![Jiri Olsa](/assets/img/avatar_default.png)
If one filter item (for set_ftrace_filter and set_ftrace_notrace) is being setup by more than 1 consecutive writes (FTRACE_ITER_CONT flag), it won't be handled corretly. I used following program to test/verify: [snip] #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> int main(int argc, char **argv) { int fd, i; char *file = argv[1]; if (-1 == (fd = open(file, O_WRONLY))) { perror("open failed"); return -1; } for(i = 0; i < (argc - 2); i++) { int len = strlen(argv[2+i]); int cnt, off = 0; while(len) { cnt = write(fd, argv[2+i] + off, len); len -= cnt; off += cnt; } } close(fd); return 0; } [snip] before change: sh-4.0# echo > ./set_ftrace_filter sh-4.0# /test ./set_ftrace_filter "sys" "_open " sh-4.0# cat ./set_ftrace_filter #### all functions enabled #### sh-4.0# after change: sh-4.0# echo > ./set_ftrace_notrace sh-4.0# test ./set_ftrace_notrace "sys" "_open " sh-4.0# cat ./set_ftrace_notrace sys_open sh-4.0# Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20090811152904.GA26065@jolsa.lab.eng.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
3445 lines
71 KiB
C
3445 lines
71 KiB
C
/*
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* Infrastructure for profiling code inserted by 'gcc -pg'.
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
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*
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* Originally ported from the -rt patch by:
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* Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
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*
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* Based on code in the latency_tracer, that is:
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*
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 William Lee Irwin III
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*/
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#include <linux/stop_machine.h>
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#include <linux/clocksource.h>
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#include <linux/kallsyms.h>
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#include <linux/seq_file.h>
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#include <linux/suspend.h>
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#include <linux/debugfs.h>
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#include <linux/hardirq.h>
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#include <linux/kthread.h>
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#include <linux/uaccess.h>
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#include <linux/kprobes.h>
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#include <linux/ftrace.h>
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#include <linux/sysctl.h>
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#include <linux/ctype.h>
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#include <linux/list.h>
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#include <linux/hash.h>
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#include <trace/events/sched.h>
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#include <asm/ftrace.h>
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#include <asm/setup.h>
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#include "trace_output.h"
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#include "trace_stat.h"
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#define FTRACE_WARN_ON(cond) \
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do { \
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if (WARN_ON(cond)) \
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ftrace_kill(); \
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} while (0)
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#define FTRACE_WARN_ON_ONCE(cond) \
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do { \
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if (WARN_ON_ONCE(cond)) \
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ftrace_kill(); \
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} while (0)
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/* hash bits for specific function selection */
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#define FTRACE_HASH_BITS 7
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#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
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/* ftrace_enabled is a method to turn ftrace on or off */
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int ftrace_enabled __read_mostly;
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static int last_ftrace_enabled;
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/* Quick disabling of function tracer. */
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int function_trace_stop;
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/*
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* ftrace_disabled is set when an anomaly is discovered.
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* ftrace_disabled is much stronger than ftrace_enabled.
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*/
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static int ftrace_disabled __read_mostly;
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static DEFINE_MUTEX(ftrace_lock);
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static struct ftrace_ops ftrace_list_end __read_mostly =
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{
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.func = ftrace_stub,
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};
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static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
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ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
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ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
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ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
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static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
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{
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struct ftrace_ops *op = ftrace_list;
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/* in case someone actually ports this to alpha! */
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read_barrier_depends();
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while (op != &ftrace_list_end) {
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/* silly alpha */
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read_barrier_depends();
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op->func(ip, parent_ip);
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op = op->next;
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};
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}
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static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
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{
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if (!test_tsk_trace_trace(current))
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return;
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ftrace_pid_function(ip, parent_ip);
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}
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static void set_ftrace_pid_function(ftrace_func_t func)
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{
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/* do not set ftrace_pid_function to itself! */
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if (func != ftrace_pid_func)
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ftrace_pid_function = func;
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}
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/**
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* clear_ftrace_function - reset the ftrace function
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*
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* This NULLs the ftrace function and in essence stops
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* tracing. There may be lag
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*/
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void clear_ftrace_function(void)
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{
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ftrace_trace_function = ftrace_stub;
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__ftrace_trace_function = ftrace_stub;
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ftrace_pid_function = ftrace_stub;
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}
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#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
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/*
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* For those archs that do not test ftrace_trace_stop in their
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* mcount call site, we need to do it from C.
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*/
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static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
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{
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if (function_trace_stop)
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return;
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__ftrace_trace_function(ip, parent_ip);
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}
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#endif
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static int __register_ftrace_function(struct ftrace_ops *ops)
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{
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ops->next = ftrace_list;
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/*
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* We are entering ops into the ftrace_list but another
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* CPU might be walking that list. We need to make sure
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* the ops->next pointer is valid before another CPU sees
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* the ops pointer included into the ftrace_list.
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*/
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smp_wmb();
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ftrace_list = ops;
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if (ftrace_enabled) {
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ftrace_func_t func;
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if (ops->next == &ftrace_list_end)
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func = ops->func;
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else
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func = ftrace_list_func;
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if (ftrace_pid_trace) {
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set_ftrace_pid_function(func);
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func = ftrace_pid_func;
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}
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/*
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* For one func, simply call it directly.
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* For more than one func, call the chain.
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*/
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#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
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ftrace_trace_function = func;
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#else
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__ftrace_trace_function = func;
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ftrace_trace_function = ftrace_test_stop_func;
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#endif
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}
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return 0;
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}
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static int __unregister_ftrace_function(struct ftrace_ops *ops)
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{
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struct ftrace_ops **p;
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/*
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* If we are removing the last function, then simply point
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* to the ftrace_stub.
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*/
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if (ftrace_list == ops && ops->next == &ftrace_list_end) {
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ftrace_trace_function = ftrace_stub;
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ftrace_list = &ftrace_list_end;
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return 0;
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}
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for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
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if (*p == ops)
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break;
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if (*p != ops)
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return -1;
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*p = (*p)->next;
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if (ftrace_enabled) {
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/* If we only have one func left, then call that directly */
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if (ftrace_list->next == &ftrace_list_end) {
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ftrace_func_t func = ftrace_list->func;
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if (ftrace_pid_trace) {
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set_ftrace_pid_function(func);
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func = ftrace_pid_func;
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}
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#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
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ftrace_trace_function = func;
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#else
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__ftrace_trace_function = func;
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#endif
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}
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}
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return 0;
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}
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static void ftrace_update_pid_func(void)
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{
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ftrace_func_t func;
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if (ftrace_trace_function == ftrace_stub)
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return;
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func = ftrace_trace_function;
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if (ftrace_pid_trace) {
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set_ftrace_pid_function(func);
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func = ftrace_pid_func;
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} else {
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if (func == ftrace_pid_func)
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func = ftrace_pid_function;
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}
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#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
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ftrace_trace_function = func;
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#else
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__ftrace_trace_function = func;
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#endif
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}
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#ifdef CONFIG_FUNCTION_PROFILER
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struct ftrace_profile {
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struct hlist_node node;
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unsigned long ip;
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unsigned long counter;
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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unsigned long long time;
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#endif
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};
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struct ftrace_profile_page {
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struct ftrace_profile_page *next;
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unsigned long index;
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struct ftrace_profile records[];
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};
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struct ftrace_profile_stat {
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atomic_t disabled;
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struct hlist_head *hash;
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struct ftrace_profile_page *pages;
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struct ftrace_profile_page *start;
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struct tracer_stat stat;
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};
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#define PROFILE_RECORDS_SIZE \
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(PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
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#define PROFILES_PER_PAGE \
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(PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
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static int ftrace_profile_bits __read_mostly;
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static int ftrace_profile_enabled __read_mostly;
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/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
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static DEFINE_MUTEX(ftrace_profile_lock);
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static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
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#define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
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static void *
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function_stat_next(void *v, int idx)
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{
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struct ftrace_profile *rec = v;
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struct ftrace_profile_page *pg;
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pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
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again:
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if (idx != 0)
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rec++;
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if ((void *)rec >= (void *)&pg->records[pg->index]) {
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pg = pg->next;
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if (!pg)
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return NULL;
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rec = &pg->records[0];
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if (!rec->counter)
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goto again;
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}
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return rec;
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}
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static void *function_stat_start(struct tracer_stat *trace)
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{
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struct ftrace_profile_stat *stat =
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container_of(trace, struct ftrace_profile_stat, stat);
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if (!stat || !stat->start)
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return NULL;
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return function_stat_next(&stat->start->records[0], 0);
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}
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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/* function graph compares on total time */
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static int function_stat_cmp(void *p1, void *p2)
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{
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struct ftrace_profile *a = p1;
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struct ftrace_profile *b = p2;
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if (a->time < b->time)
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return -1;
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if (a->time > b->time)
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return 1;
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else
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return 0;
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}
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#else
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/* not function graph compares against hits */
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static int function_stat_cmp(void *p1, void *p2)
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{
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struct ftrace_profile *a = p1;
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struct ftrace_profile *b = p2;
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if (a->counter < b->counter)
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return -1;
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if (a->counter > b->counter)
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return 1;
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else
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return 0;
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}
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#endif
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static int function_stat_headers(struct seq_file *m)
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{
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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seq_printf(m, " Function "
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"Hit Time Avg\n"
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" -------- "
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"--- ---- ---\n");
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#else
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seq_printf(m, " Function Hit\n"
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" -------- ---\n");
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#endif
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return 0;
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}
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static int function_stat_show(struct seq_file *m, void *v)
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{
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struct ftrace_profile *rec = v;
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char str[KSYM_SYMBOL_LEN];
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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static DEFINE_MUTEX(mutex);
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static struct trace_seq s;
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unsigned long long avg;
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#endif
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kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
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seq_printf(m, " %-30.30s %10lu", str, rec->counter);
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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seq_printf(m, " ");
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avg = rec->time;
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do_div(avg, rec->counter);
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mutex_lock(&mutex);
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trace_seq_init(&s);
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trace_print_graph_duration(rec->time, &s);
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trace_seq_puts(&s, " ");
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trace_print_graph_duration(avg, &s);
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trace_print_seq(m, &s);
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mutex_unlock(&mutex);
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#endif
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seq_putc(m, '\n');
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return 0;
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}
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static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
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{
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struct ftrace_profile_page *pg;
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pg = stat->pages = stat->start;
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while (pg) {
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memset(pg->records, 0, PROFILE_RECORDS_SIZE);
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pg->index = 0;
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pg = pg->next;
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}
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memset(stat->hash, 0,
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FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
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}
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int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
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{
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struct ftrace_profile_page *pg;
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int functions;
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int pages;
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int i;
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/* If we already allocated, do nothing */
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if (stat->pages)
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return 0;
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stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
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if (!stat->pages)
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return -ENOMEM;
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#ifdef CONFIG_DYNAMIC_FTRACE
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functions = ftrace_update_tot_cnt;
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#else
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/*
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* We do not know the number of functions that exist because
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* dynamic tracing is what counts them. With past experience
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* we have around 20K functions. That should be more than enough.
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* It is highly unlikely we will execute every function in
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* the kernel.
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*/
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functions = 20000;
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#endif
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pg = stat->start = stat->pages;
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pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
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for (i = 0; i < pages; i++) {
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pg->next = (void *)get_zeroed_page(GFP_KERNEL);
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if (!pg->next)
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goto out_free;
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pg = pg->next;
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}
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return 0;
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out_free:
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pg = stat->start;
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while (pg) {
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unsigned long tmp = (unsigned long)pg;
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pg = pg->next;
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free_page(tmp);
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}
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free_page((unsigned long)stat->pages);
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stat->pages = NULL;
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stat->start = NULL;
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return -ENOMEM;
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}
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static int ftrace_profile_init_cpu(int cpu)
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{
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struct ftrace_profile_stat *stat;
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int size;
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stat = &per_cpu(ftrace_profile_stats, cpu);
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if (stat->hash) {
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/* If the profile is already created, simply reset it */
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ftrace_profile_reset(stat);
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return 0;
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}
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|
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/*
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* We are profiling all functions, but usually only a few thousand
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* functions are hit. We'll make a hash of 1024 items.
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*/
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size = FTRACE_PROFILE_HASH_SIZE;
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stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
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|
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if (!stat->hash)
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return -ENOMEM;
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|
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if (!ftrace_profile_bits) {
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size--;
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for (; size; size >>= 1)
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ftrace_profile_bits++;
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}
|
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|
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/* Preallocate the function profiling pages */
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if (ftrace_profile_pages_init(stat) < 0) {
|
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kfree(stat->hash);
|
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stat->hash = NULL;
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return -ENOMEM;
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}
|
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|
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return 0;
|
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}
|
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|
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static int ftrace_profile_init(void)
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{
|
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int cpu;
|
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int ret = 0;
|
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|
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for_each_online_cpu(cpu) {
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ret = ftrace_profile_init_cpu(cpu);
|
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if (ret)
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break;
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}
|
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|
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return ret;
|
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}
|
|
|
|
/* interrupts must be disabled */
|
|
static struct ftrace_profile *
|
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ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
|
|
{
|
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struct ftrace_profile *rec;
|
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struct hlist_head *hhd;
|
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struct hlist_node *n;
|
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unsigned long key;
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|
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key = hash_long(ip, ftrace_profile_bits);
|
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hhd = &stat->hash[key];
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|
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if (hlist_empty(hhd))
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return NULL;
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|
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hlist_for_each_entry_rcu(rec, n, hhd, node) {
|
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if (rec->ip == ip)
|
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return rec;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void ftrace_add_profile(struct ftrace_profile_stat *stat,
|
|
struct ftrace_profile *rec)
|
|
{
|
|
unsigned long key;
|
|
|
|
key = hash_long(rec->ip, ftrace_profile_bits);
|
|
hlist_add_head_rcu(&rec->node, &stat->hash[key]);
|
|
}
|
|
|
|
/*
|
|
* The memory is already allocated, this simply finds a new record to use.
|
|
*/
|
|
static struct ftrace_profile *
|
|
ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
|
|
{
|
|
struct ftrace_profile *rec = NULL;
|
|
|
|
/* prevent recursion (from NMIs) */
|
|
if (atomic_inc_return(&stat->disabled) != 1)
|
|
goto out;
|
|
|
|
/*
|
|
* Try to find the function again since an NMI
|
|
* could have added it
|
|
*/
|
|
rec = ftrace_find_profiled_func(stat, ip);
|
|
if (rec)
|
|
goto out;
|
|
|
|
if (stat->pages->index == PROFILES_PER_PAGE) {
|
|
if (!stat->pages->next)
|
|
goto out;
|
|
stat->pages = stat->pages->next;
|
|
}
|
|
|
|
rec = &stat->pages->records[stat->pages->index++];
|
|
rec->ip = ip;
|
|
ftrace_add_profile(stat, rec);
|
|
|
|
out:
|
|
atomic_dec(&stat->disabled);
|
|
|
|
return rec;
|
|
}
|
|
|
|
static void
|
|
function_profile_call(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
struct ftrace_profile *rec;
|
|
unsigned long flags;
|
|
|
|
if (!ftrace_profile_enabled)
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
|
|
stat = &__get_cpu_var(ftrace_profile_stats);
|
|
if (!stat->hash || !ftrace_profile_enabled)
|
|
goto out;
|
|
|
|
rec = ftrace_find_profiled_func(stat, ip);
|
|
if (!rec) {
|
|
rec = ftrace_profile_alloc(stat, ip);
|
|
if (!rec)
|
|
goto out;
|
|
}
|
|
|
|
rec->counter++;
|
|
out:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
static int profile_graph_entry(struct ftrace_graph_ent *trace)
|
|
{
|
|
function_profile_call(trace->func, 0);
|
|
return 1;
|
|
}
|
|
|
|
static void profile_graph_return(struct ftrace_graph_ret *trace)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
unsigned long long calltime;
|
|
struct ftrace_profile *rec;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
stat = &__get_cpu_var(ftrace_profile_stats);
|
|
if (!stat->hash || !ftrace_profile_enabled)
|
|
goto out;
|
|
|
|
calltime = trace->rettime - trace->calltime;
|
|
|
|
if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
|
|
int index;
|
|
|
|
index = trace->depth;
|
|
|
|
/* Append this call time to the parent time to subtract */
|
|
if (index)
|
|
current->ret_stack[index - 1].subtime += calltime;
|
|
|
|
if (current->ret_stack[index].subtime < calltime)
|
|
calltime -= current->ret_stack[index].subtime;
|
|
else
|
|
calltime = 0;
|
|
}
|
|
|
|
rec = ftrace_find_profiled_func(stat, trace->func);
|
|
if (rec)
|
|
rec->time += calltime;
|
|
|
|
out:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static int register_ftrace_profiler(void)
|
|
{
|
|
return register_ftrace_graph(&profile_graph_return,
|
|
&profile_graph_entry);
|
|
}
|
|
|
|
static void unregister_ftrace_profiler(void)
|
|
{
|
|
unregister_ftrace_graph();
|
|
}
|
|
#else
|
|
static struct ftrace_ops ftrace_profile_ops __read_mostly =
|
|
{
|
|
.func = function_profile_call,
|
|
};
|
|
|
|
static int register_ftrace_profiler(void)
|
|
{
|
|
return register_ftrace_function(&ftrace_profile_ops);
|
|
}
|
|
|
|
static void unregister_ftrace_profiler(void)
|
|
{
|
|
unregister_ftrace_function(&ftrace_profile_ops);
|
|
}
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
static ssize_t
|
|
ftrace_profile_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long val;
|
|
char buf[64]; /* big enough to hold a number */
|
|
int ret;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
ret = strict_strtoul(buf, 10, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
val = !!val;
|
|
|
|
mutex_lock(&ftrace_profile_lock);
|
|
if (ftrace_profile_enabled ^ val) {
|
|
if (val) {
|
|
ret = ftrace_profile_init();
|
|
if (ret < 0) {
|
|
cnt = ret;
|
|
goto out;
|
|
}
|
|
|
|
ret = register_ftrace_profiler();
|
|
if (ret < 0) {
|
|
cnt = ret;
|
|
goto out;
|
|
}
|
|
ftrace_profile_enabled = 1;
|
|
} else {
|
|
ftrace_profile_enabled = 0;
|
|
/*
|
|
* unregister_ftrace_profiler calls stop_machine
|
|
* so this acts like an synchronize_sched.
|
|
*/
|
|
unregister_ftrace_profiler();
|
|
}
|
|
}
|
|
out:
|
|
mutex_unlock(&ftrace_profile_lock);
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_profile_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64]; /* big enough to hold a number */
|
|
int r;
|
|
|
|
r = sprintf(buf, "%u\n", ftrace_profile_enabled);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static const struct file_operations ftrace_profile_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = ftrace_profile_read,
|
|
.write = ftrace_profile_write,
|
|
};
|
|
|
|
/* used to initialize the real stat files */
|
|
static struct tracer_stat function_stats __initdata = {
|
|
.name = "functions",
|
|
.stat_start = function_stat_start,
|
|
.stat_next = function_stat_next,
|
|
.stat_cmp = function_stat_cmp,
|
|
.stat_headers = function_stat_headers,
|
|
.stat_show = function_stat_show
|
|
};
|
|
|
|
static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
|
|
{
|
|
struct ftrace_profile_stat *stat;
|
|
struct dentry *entry;
|
|
char *name;
|
|
int ret;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
stat = &per_cpu(ftrace_profile_stats, cpu);
|
|
|
|
/* allocate enough for function name + cpu number */
|
|
name = kmalloc(32, GFP_KERNEL);
|
|
if (!name) {
|
|
/*
|
|
* The files created are permanent, if something happens
|
|
* we still do not free memory.
|
|
*/
|
|
WARN(1,
|
|
"Could not allocate stat file for cpu %d\n",
|
|
cpu);
|
|
return;
|
|
}
|
|
stat->stat = function_stats;
|
|
snprintf(name, 32, "function%d", cpu);
|
|
stat->stat.name = name;
|
|
ret = register_stat_tracer(&stat->stat);
|
|
if (ret) {
|
|
WARN(1,
|
|
"Could not register function stat for cpu %d\n",
|
|
cpu);
|
|
kfree(name);
|
|
return;
|
|
}
|
|
}
|
|
|
|
entry = debugfs_create_file("function_profile_enabled", 0644,
|
|
d_tracer, NULL, &ftrace_profile_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'function_profile_enabled' entry\n");
|
|
}
|
|
|
|
#else /* CONFIG_FUNCTION_PROFILER */
|
|
static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
|
|
{
|
|
}
|
|
#endif /* CONFIG_FUNCTION_PROFILER */
|
|
|
|
/* set when tracing only a pid */
|
|
struct pid *ftrace_pid_trace;
|
|
static struct pid * const ftrace_swapper_pid = &init_struct_pid;
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
#ifndef CONFIG_FTRACE_MCOUNT_RECORD
|
|
# error Dynamic ftrace depends on MCOUNT_RECORD
|
|
#endif
|
|
|
|
static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
|
|
|
|
struct ftrace_func_probe {
|
|
struct hlist_node node;
|
|
struct ftrace_probe_ops *ops;
|
|
unsigned long flags;
|
|
unsigned long ip;
|
|
void *data;
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
enum {
|
|
FTRACE_ENABLE_CALLS = (1 << 0),
|
|
FTRACE_DISABLE_CALLS = (1 << 1),
|
|
FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
|
|
FTRACE_ENABLE_MCOUNT = (1 << 3),
|
|
FTRACE_DISABLE_MCOUNT = (1 << 4),
|
|
FTRACE_START_FUNC_RET = (1 << 5),
|
|
FTRACE_STOP_FUNC_RET = (1 << 6),
|
|
};
|
|
|
|
static int ftrace_filtered;
|
|
|
|
static struct dyn_ftrace *ftrace_new_addrs;
|
|
|
|
static DEFINE_MUTEX(ftrace_regex_lock);
|
|
|
|
struct ftrace_page {
|
|
struct ftrace_page *next;
|
|
int index;
|
|
struct dyn_ftrace records[];
|
|
};
|
|
|
|
#define ENTRIES_PER_PAGE \
|
|
((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
|
|
|
|
/* estimate from running different kernels */
|
|
#define NR_TO_INIT 10000
|
|
|
|
static struct ftrace_page *ftrace_pages_start;
|
|
static struct ftrace_page *ftrace_pages;
|
|
|
|
static struct dyn_ftrace *ftrace_free_records;
|
|
|
|
/*
|
|
* This is a double for. Do not use 'break' to break out of the loop,
|
|
* you must use a goto.
|
|
*/
|
|
#define do_for_each_ftrace_rec(pg, rec) \
|
|
for (pg = ftrace_pages_start; pg; pg = pg->next) { \
|
|
int _____i; \
|
|
for (_____i = 0; _____i < pg->index; _____i++) { \
|
|
rec = &pg->records[_____i];
|
|
|
|
#define while_for_each_ftrace_rec() \
|
|
} \
|
|
}
|
|
|
|
#ifdef CONFIG_KPROBES
|
|
|
|
static int frozen_record_count;
|
|
|
|
static inline void freeze_record(struct dyn_ftrace *rec)
|
|
{
|
|
if (!(rec->flags & FTRACE_FL_FROZEN)) {
|
|
rec->flags |= FTRACE_FL_FROZEN;
|
|
frozen_record_count++;
|
|
}
|
|
}
|
|
|
|
static inline void unfreeze_record(struct dyn_ftrace *rec)
|
|
{
|
|
if (rec->flags & FTRACE_FL_FROZEN) {
|
|
rec->flags &= ~FTRACE_FL_FROZEN;
|
|
frozen_record_count--;
|
|
}
|
|
}
|
|
|
|
static inline int record_frozen(struct dyn_ftrace *rec)
|
|
{
|
|
return rec->flags & FTRACE_FL_FROZEN;
|
|
}
|
|
#else
|
|
# define freeze_record(rec) ({ 0; })
|
|
# define unfreeze_record(rec) ({ 0; })
|
|
# define record_frozen(rec) ({ 0; })
|
|
#endif /* CONFIG_KPROBES */
|
|
|
|
static void ftrace_free_rec(struct dyn_ftrace *rec)
|
|
{
|
|
rec->freelist = ftrace_free_records;
|
|
ftrace_free_records = rec;
|
|
rec->flags |= FTRACE_FL_FREE;
|
|
}
|
|
|
|
static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
|
|
/* First check for freed records */
|
|
if (ftrace_free_records) {
|
|
rec = ftrace_free_records;
|
|
|
|
if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
ftrace_free_records = NULL;
|
|
return NULL;
|
|
}
|
|
|
|
ftrace_free_records = rec->freelist;
|
|
memset(rec, 0, sizeof(*rec));
|
|
return rec;
|
|
}
|
|
|
|
if (ftrace_pages->index == ENTRIES_PER_PAGE) {
|
|
if (!ftrace_pages->next) {
|
|
/* allocate another page */
|
|
ftrace_pages->next =
|
|
(void *)get_zeroed_page(GFP_KERNEL);
|
|
if (!ftrace_pages->next)
|
|
return NULL;
|
|
}
|
|
ftrace_pages = ftrace_pages->next;
|
|
}
|
|
|
|
return &ftrace_pages->records[ftrace_pages->index++];
|
|
}
|
|
|
|
static struct dyn_ftrace *
|
|
ftrace_record_ip(unsigned long ip)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
|
|
if (ftrace_disabled)
|
|
return NULL;
|
|
|
|
rec = ftrace_alloc_dyn_node(ip);
|
|
if (!rec)
|
|
return NULL;
|
|
|
|
rec->ip = ip;
|
|
rec->newlist = ftrace_new_addrs;
|
|
ftrace_new_addrs = rec;
|
|
|
|
return rec;
|
|
}
|
|
|
|
static void print_ip_ins(const char *fmt, unsigned char *p)
|
|
{
|
|
int i;
|
|
|
|
printk(KERN_CONT "%s", fmt);
|
|
|
|
for (i = 0; i < MCOUNT_INSN_SIZE; i++)
|
|
printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
|
|
}
|
|
|
|
static void ftrace_bug(int failed, unsigned long ip)
|
|
{
|
|
switch (failed) {
|
|
case -EFAULT:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace faulted on modifying ");
|
|
print_ip_sym(ip);
|
|
break;
|
|
case -EINVAL:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace failed to modify ");
|
|
print_ip_sym(ip);
|
|
print_ip_ins(" actual: ", (unsigned char *)ip);
|
|
printk(KERN_CONT "\n");
|
|
break;
|
|
case -EPERM:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace faulted on writing ");
|
|
print_ip_sym(ip);
|
|
break;
|
|
default:
|
|
FTRACE_WARN_ON_ONCE(1);
|
|
pr_info("ftrace faulted on unknown error ");
|
|
print_ip_sym(ip);
|
|
}
|
|
}
|
|
|
|
|
|
static int
|
|
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
|
|
{
|
|
unsigned long ftrace_addr;
|
|
unsigned long ip, fl;
|
|
|
|
ftrace_addr = (unsigned long)FTRACE_ADDR;
|
|
|
|
ip = rec->ip;
|
|
|
|
/*
|
|
* If this record is not to be traced and
|
|
* it is not enabled then do nothing.
|
|
*
|
|
* If this record is not to be traced and
|
|
* it is enabled then disable it.
|
|
*
|
|
*/
|
|
if (rec->flags & FTRACE_FL_NOTRACE) {
|
|
if (rec->flags & FTRACE_FL_ENABLED)
|
|
rec->flags &= ~FTRACE_FL_ENABLED;
|
|
else
|
|
return 0;
|
|
|
|
} else if (ftrace_filtered && enable) {
|
|
/*
|
|
* Filtering is on:
|
|
*/
|
|
|
|
fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
|
|
|
|
/* Record is filtered and enabled, do nothing */
|
|
if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
|
|
return 0;
|
|
|
|
/* Record is not filtered or enabled, do nothing */
|
|
if (!fl)
|
|
return 0;
|
|
|
|
/* Record is not filtered but enabled, disable it */
|
|
if (fl == FTRACE_FL_ENABLED)
|
|
rec->flags &= ~FTRACE_FL_ENABLED;
|
|
else
|
|
/* Otherwise record is filtered but not enabled, enable it */
|
|
rec->flags |= FTRACE_FL_ENABLED;
|
|
} else {
|
|
/* Disable or not filtered */
|
|
|
|
if (enable) {
|
|
/* if record is enabled, do nothing */
|
|
if (rec->flags & FTRACE_FL_ENABLED)
|
|
return 0;
|
|
|
|
rec->flags |= FTRACE_FL_ENABLED;
|
|
|
|
} else {
|
|
|
|
/* if record is not enabled, do nothing */
|
|
if (!(rec->flags & FTRACE_FL_ENABLED))
|
|
return 0;
|
|
|
|
rec->flags &= ~FTRACE_FL_ENABLED;
|
|
}
|
|
}
|
|
|
|
if (rec->flags & FTRACE_FL_ENABLED)
|
|
return ftrace_make_call(rec, ftrace_addr);
|
|
else
|
|
return ftrace_make_nop(NULL, rec, ftrace_addr);
|
|
}
|
|
|
|
static void ftrace_replace_code(int enable)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
struct ftrace_page *pg;
|
|
int failed;
|
|
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
/*
|
|
* Skip over free records, records that have
|
|
* failed and not converted.
|
|
*/
|
|
if (rec->flags & FTRACE_FL_FREE ||
|
|
rec->flags & FTRACE_FL_FAILED ||
|
|
!(rec->flags & FTRACE_FL_CONVERTED))
|
|
continue;
|
|
|
|
/* ignore updates to this record's mcount site */
|
|
if (get_kprobe((void *)rec->ip)) {
|
|
freeze_record(rec);
|
|
continue;
|
|
} else {
|
|
unfreeze_record(rec);
|
|
}
|
|
|
|
failed = __ftrace_replace_code(rec, enable);
|
|
if (failed) {
|
|
rec->flags |= FTRACE_FL_FAILED;
|
|
if ((system_state == SYSTEM_BOOTING) ||
|
|
!core_kernel_text(rec->ip)) {
|
|
ftrace_free_rec(rec);
|
|
} else {
|
|
ftrace_bug(failed, rec->ip);
|
|
/* Stop processing */
|
|
return;
|
|
}
|
|
}
|
|
} while_for_each_ftrace_rec();
|
|
}
|
|
|
|
static int
|
|
ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
|
|
{
|
|
unsigned long ip;
|
|
int ret;
|
|
|
|
ip = rec->ip;
|
|
|
|
ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
|
|
if (ret) {
|
|
ftrace_bug(ret, ip);
|
|
rec->flags |= FTRACE_FL_FAILED;
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* archs can override this function if they must do something
|
|
* before the modifying code is performed.
|
|
*/
|
|
int __weak ftrace_arch_code_modify_prepare(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* archs can override this function if they must do something
|
|
* after the modifying code is performed.
|
|
*/
|
|
int __weak ftrace_arch_code_modify_post_process(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int __ftrace_modify_code(void *data)
|
|
{
|
|
int *command = data;
|
|
|
|
if (*command & FTRACE_ENABLE_CALLS)
|
|
ftrace_replace_code(1);
|
|
else if (*command & FTRACE_DISABLE_CALLS)
|
|
ftrace_replace_code(0);
|
|
|
|
if (*command & FTRACE_UPDATE_TRACE_FUNC)
|
|
ftrace_update_ftrace_func(ftrace_trace_function);
|
|
|
|
if (*command & FTRACE_START_FUNC_RET)
|
|
ftrace_enable_ftrace_graph_caller();
|
|
else if (*command & FTRACE_STOP_FUNC_RET)
|
|
ftrace_disable_ftrace_graph_caller();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ftrace_run_update_code(int command)
|
|
{
|
|
int ret;
|
|
|
|
ret = ftrace_arch_code_modify_prepare();
|
|
FTRACE_WARN_ON(ret);
|
|
if (ret)
|
|
return;
|
|
|
|
stop_machine(__ftrace_modify_code, &command, NULL);
|
|
|
|
ret = ftrace_arch_code_modify_post_process();
|
|
FTRACE_WARN_ON(ret);
|
|
}
|
|
|
|
static ftrace_func_t saved_ftrace_func;
|
|
static int ftrace_start_up;
|
|
|
|
static void ftrace_startup_enable(int command)
|
|
{
|
|
if (saved_ftrace_func != ftrace_trace_function) {
|
|
saved_ftrace_func = ftrace_trace_function;
|
|
command |= FTRACE_UPDATE_TRACE_FUNC;
|
|
}
|
|
|
|
if (!command || !ftrace_enabled)
|
|
return;
|
|
|
|
ftrace_run_update_code(command);
|
|
}
|
|
|
|
static void ftrace_startup(int command)
|
|
{
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
ftrace_start_up++;
|
|
command |= FTRACE_ENABLE_CALLS;
|
|
|
|
ftrace_startup_enable(command);
|
|
}
|
|
|
|
static void ftrace_shutdown(int command)
|
|
{
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
ftrace_start_up--;
|
|
/*
|
|
* Just warn in case of unbalance, no need to kill ftrace, it's not
|
|
* critical but the ftrace_call callers may be never nopped again after
|
|
* further ftrace uses.
|
|
*/
|
|
WARN_ON_ONCE(ftrace_start_up < 0);
|
|
|
|
if (!ftrace_start_up)
|
|
command |= FTRACE_DISABLE_CALLS;
|
|
|
|
if (saved_ftrace_func != ftrace_trace_function) {
|
|
saved_ftrace_func = ftrace_trace_function;
|
|
command |= FTRACE_UPDATE_TRACE_FUNC;
|
|
}
|
|
|
|
if (!command || !ftrace_enabled)
|
|
return;
|
|
|
|
ftrace_run_update_code(command);
|
|
}
|
|
|
|
static void ftrace_startup_sysctl(void)
|
|
{
|
|
int command = FTRACE_ENABLE_MCOUNT;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
/* Force update next time */
|
|
saved_ftrace_func = NULL;
|
|
/* ftrace_start_up is true if we want ftrace running */
|
|
if (ftrace_start_up)
|
|
command |= FTRACE_ENABLE_CALLS;
|
|
|
|
ftrace_run_update_code(command);
|
|
}
|
|
|
|
static void ftrace_shutdown_sysctl(void)
|
|
{
|
|
int command = FTRACE_DISABLE_MCOUNT;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
/* ftrace_start_up is true if ftrace is running */
|
|
if (ftrace_start_up)
|
|
command |= FTRACE_DISABLE_CALLS;
|
|
|
|
ftrace_run_update_code(command);
|
|
}
|
|
|
|
static cycle_t ftrace_update_time;
|
|
static unsigned long ftrace_update_cnt;
|
|
unsigned long ftrace_update_tot_cnt;
|
|
|
|
static int ftrace_update_code(struct module *mod)
|
|
{
|
|
struct dyn_ftrace *p;
|
|
cycle_t start, stop;
|
|
|
|
start = ftrace_now(raw_smp_processor_id());
|
|
ftrace_update_cnt = 0;
|
|
|
|
while (ftrace_new_addrs) {
|
|
|
|
/* If something went wrong, bail without enabling anything */
|
|
if (unlikely(ftrace_disabled))
|
|
return -1;
|
|
|
|
p = ftrace_new_addrs;
|
|
ftrace_new_addrs = p->newlist;
|
|
p->flags = 0L;
|
|
|
|
/* convert record (i.e, patch mcount-call with NOP) */
|
|
if (ftrace_code_disable(mod, p)) {
|
|
p->flags |= FTRACE_FL_CONVERTED;
|
|
ftrace_update_cnt++;
|
|
} else
|
|
ftrace_free_rec(p);
|
|
}
|
|
|
|
stop = ftrace_now(raw_smp_processor_id());
|
|
ftrace_update_time = stop - start;
|
|
ftrace_update_tot_cnt += ftrace_update_cnt;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
|
|
{
|
|
struct ftrace_page *pg;
|
|
int cnt;
|
|
int i;
|
|
|
|
/* allocate a few pages */
|
|
ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
|
|
if (!ftrace_pages_start)
|
|
return -1;
|
|
|
|
/*
|
|
* Allocate a few more pages.
|
|
*
|
|
* TODO: have some parser search vmlinux before
|
|
* final linking to find all calls to ftrace.
|
|
* Then we can:
|
|
* a) know how many pages to allocate.
|
|
* and/or
|
|
* b) set up the table then.
|
|
*
|
|
* The dynamic code is still necessary for
|
|
* modules.
|
|
*/
|
|
|
|
pg = ftrace_pages = ftrace_pages_start;
|
|
|
|
cnt = num_to_init / ENTRIES_PER_PAGE;
|
|
pr_info("ftrace: allocating %ld entries in %d pages\n",
|
|
num_to_init, cnt + 1);
|
|
|
|
for (i = 0; i < cnt; i++) {
|
|
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
|
|
|
|
/* If we fail, we'll try later anyway */
|
|
if (!pg->next)
|
|
break;
|
|
|
|
pg = pg->next;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
enum {
|
|
FTRACE_ITER_FILTER = (1 << 0),
|
|
FTRACE_ITER_CONT = (1 << 1),
|
|
FTRACE_ITER_NOTRACE = (1 << 2),
|
|
FTRACE_ITER_FAILURES = (1 << 3),
|
|
FTRACE_ITER_PRINTALL = (1 << 4),
|
|
FTRACE_ITER_HASH = (1 << 5),
|
|
};
|
|
|
|
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
|
|
|
|
struct ftrace_iterator {
|
|
struct ftrace_page *pg;
|
|
int hidx;
|
|
int idx;
|
|
unsigned flags;
|
|
unsigned char buffer[FTRACE_BUFF_MAX+1];
|
|
unsigned buffer_idx;
|
|
unsigned filtered;
|
|
};
|
|
|
|
static void *
|
|
t_hash_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct hlist_node *hnd = v;
|
|
struct hlist_head *hhd;
|
|
|
|
WARN_ON(!(iter->flags & FTRACE_ITER_HASH));
|
|
|
|
(*pos)++;
|
|
|
|
retry:
|
|
if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
|
|
return NULL;
|
|
|
|
hhd = &ftrace_func_hash[iter->hidx];
|
|
|
|
if (hlist_empty(hhd)) {
|
|
iter->hidx++;
|
|
hnd = NULL;
|
|
goto retry;
|
|
}
|
|
|
|
if (!hnd)
|
|
hnd = hhd->first;
|
|
else {
|
|
hnd = hnd->next;
|
|
if (!hnd) {
|
|
iter->hidx++;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
return hnd;
|
|
}
|
|
|
|
static void *t_hash_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
void *p = NULL;
|
|
loff_t l;
|
|
|
|
if (!(iter->flags & FTRACE_ITER_HASH))
|
|
*pos = 0;
|
|
|
|
iter->flags |= FTRACE_ITER_HASH;
|
|
|
|
iter->hidx = 0;
|
|
for (l = 0; l <= *pos; ) {
|
|
p = t_hash_next(m, p, &l);
|
|
if (!p)
|
|
break;
|
|
}
|
|
return p;
|
|
}
|
|
|
|
static int t_hash_show(struct seq_file *m, void *v)
|
|
{
|
|
struct ftrace_func_probe *rec;
|
|
struct hlist_node *hnd = v;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
rec = hlist_entry(hnd, struct ftrace_func_probe, node);
|
|
|
|
if (rec->ops->print)
|
|
return rec->ops->print(m, rec->ip, rec->ops, rec->data);
|
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
|
|
seq_printf(m, "%s:", str);
|
|
|
|
kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
|
|
seq_printf(m, "%s", str);
|
|
|
|
if (rec->data)
|
|
seq_printf(m, ":%p", rec->data);
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void *
|
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct dyn_ftrace *rec = NULL;
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_next(m, v, pos);
|
|
|
|
(*pos)++;
|
|
|
|
if (iter->flags & FTRACE_ITER_PRINTALL)
|
|
return NULL;
|
|
|
|
retry:
|
|
if (iter->idx >= iter->pg->index) {
|
|
if (iter->pg->next) {
|
|
iter->pg = iter->pg->next;
|
|
iter->idx = 0;
|
|
goto retry;
|
|
}
|
|
} else {
|
|
rec = &iter->pg->records[iter->idx++];
|
|
if ((rec->flags & FTRACE_FL_FREE) ||
|
|
|
|
(!(iter->flags & FTRACE_ITER_FAILURES) &&
|
|
(rec->flags & FTRACE_FL_FAILED)) ||
|
|
|
|
((iter->flags & FTRACE_ITER_FAILURES) &&
|
|
!(rec->flags & FTRACE_FL_FAILED)) ||
|
|
|
|
((iter->flags & FTRACE_ITER_FILTER) &&
|
|
!(rec->flags & FTRACE_FL_FILTER)) ||
|
|
|
|
((iter->flags & FTRACE_ITER_NOTRACE) &&
|
|
!(rec->flags & FTRACE_FL_NOTRACE))) {
|
|
rec = NULL;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
return rec;
|
|
}
|
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
void *p = NULL;
|
|
loff_t l;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
/*
|
|
* For set_ftrace_filter reading, if we have the filter
|
|
* off, we can short cut and just print out that all
|
|
* functions are enabled.
|
|
*/
|
|
if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) {
|
|
if (*pos > 0)
|
|
return t_hash_start(m, pos);
|
|
iter->flags |= FTRACE_ITER_PRINTALL;
|
|
return iter;
|
|
}
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_start(m, pos);
|
|
|
|
iter->pg = ftrace_pages_start;
|
|
iter->idx = 0;
|
|
for (l = 0; l <= *pos; ) {
|
|
p = t_next(m, p, &l);
|
|
if (!p)
|
|
break;
|
|
}
|
|
|
|
if (!p && iter->flags & FTRACE_ITER_FILTER)
|
|
return t_hash_start(m, pos);
|
|
|
|
return p;
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static int t_show(struct seq_file *m, void *v)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct dyn_ftrace *rec = v;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_show(m, v);
|
|
|
|
if (iter->flags & FTRACE_ITER_PRINTALL) {
|
|
seq_printf(m, "#### all functions enabled ####\n");
|
|
return 0;
|
|
}
|
|
|
|
if (!rec)
|
|
return 0;
|
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
|
|
|
|
seq_printf(m, "%s\n", str);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations show_ftrace_seq_ops = {
|
|
.start = t_start,
|
|
.next = t_next,
|
|
.stop = t_stop,
|
|
.show = t_show,
|
|
};
|
|
|
|
static int
|
|
ftrace_avail_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
int ret;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
iter->pg = ftrace_pages_start;
|
|
|
|
ret = seq_open(file, &show_ftrace_seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
|
|
m->private = iter;
|
|
} else {
|
|
kfree(iter);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int ftrace_avail_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *m = (struct seq_file *)file->private_data;
|
|
struct ftrace_iterator *iter = m->private;
|
|
|
|
seq_release(inode, file);
|
|
kfree(iter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_failures_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
struct seq_file *m;
|
|
struct ftrace_iterator *iter;
|
|
|
|
ret = ftrace_avail_open(inode, file);
|
|
if (!ret) {
|
|
m = (struct seq_file *)file->private_data;
|
|
iter = (struct ftrace_iterator *)m->private;
|
|
iter->flags = FTRACE_ITER_FAILURES;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void ftrace_filter_reset(int enable)
|
|
{
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
if (enable)
|
|
ftrace_filtered = 0;
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
if (rec->flags & FTRACE_FL_FAILED)
|
|
continue;
|
|
rec->flags &= ~type;
|
|
} while_for_each_ftrace_rec();
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static int
|
|
ftrace_regex_open(struct inode *inode, struct file *file, int enable)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
int ret = 0;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&ftrace_regex_lock);
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC))
|
|
ftrace_filter_reset(enable);
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter->pg = ftrace_pages_start;
|
|
iter->flags = enable ? FTRACE_ITER_FILTER :
|
|
FTRACE_ITER_NOTRACE;
|
|
|
|
ret = seq_open(file, &show_ftrace_seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = iter;
|
|
} else
|
|
kfree(iter);
|
|
} else
|
|
file->private_data = iter;
|
|
mutex_unlock(&ftrace_regex_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
ftrace_filter_open(struct inode *inode, struct file *file)
|
|
{
|
|
return ftrace_regex_open(inode, file, 1);
|
|
}
|
|
|
|
static int
|
|
ftrace_notrace_open(struct inode *inode, struct file *file)
|
|
{
|
|
return ftrace_regex_open(inode, file, 0);
|
|
}
|
|
|
|
static loff_t
|
|
ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
|
|
{
|
|
loff_t ret;
|
|
|
|
if (file->f_mode & FMODE_READ)
|
|
ret = seq_lseek(file, offset, origin);
|
|
else
|
|
file->f_pos = ret = 1;
|
|
|
|
return ret;
|
|
}
|
|
|
|
enum {
|
|
MATCH_FULL,
|
|
MATCH_FRONT_ONLY,
|
|
MATCH_MIDDLE_ONLY,
|
|
MATCH_END_ONLY,
|
|
};
|
|
|
|
/*
|
|
* (static function - no need for kernel doc)
|
|
*
|
|
* Pass in a buffer containing a glob and this function will
|
|
* set search to point to the search part of the buffer and
|
|
* return the type of search it is (see enum above).
|
|
* This does modify buff.
|
|
*
|
|
* Returns enum type.
|
|
* search returns the pointer to use for comparison.
|
|
* not returns 1 if buff started with a '!'
|
|
* 0 otherwise.
|
|
*/
|
|
static int
|
|
ftrace_setup_glob(char *buff, int len, char **search, int *not)
|
|
{
|
|
int type = MATCH_FULL;
|
|
int i;
|
|
|
|
if (buff[0] == '!') {
|
|
*not = 1;
|
|
buff++;
|
|
len--;
|
|
} else
|
|
*not = 0;
|
|
|
|
*search = buff;
|
|
|
|
for (i = 0; i < len; i++) {
|
|
if (buff[i] == '*') {
|
|
if (!i) {
|
|
*search = buff + 1;
|
|
type = MATCH_END_ONLY;
|
|
} else {
|
|
if (type == MATCH_END_ONLY)
|
|
type = MATCH_MIDDLE_ONLY;
|
|
else
|
|
type = MATCH_FRONT_ONLY;
|
|
buff[i] = 0;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return type;
|
|
}
|
|
|
|
static int ftrace_match(char *str, char *regex, int len, int type)
|
|
{
|
|
int matched = 0;
|
|
char *ptr;
|
|
|
|
switch (type) {
|
|
case MATCH_FULL:
|
|
if (strcmp(str, regex) == 0)
|
|
matched = 1;
|
|
break;
|
|
case MATCH_FRONT_ONLY:
|
|
if (strncmp(str, regex, len) == 0)
|
|
matched = 1;
|
|
break;
|
|
case MATCH_MIDDLE_ONLY:
|
|
if (strstr(str, regex))
|
|
matched = 1;
|
|
break;
|
|
case MATCH_END_ONLY:
|
|
ptr = strstr(str, regex);
|
|
if (ptr && (ptr[len] == 0))
|
|
matched = 1;
|
|
break;
|
|
}
|
|
|
|
return matched;
|
|
}
|
|
|
|
static int
|
|
ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
|
|
{
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
|
|
return ftrace_match(str, regex, len, type);
|
|
}
|
|
|
|
static void ftrace_match_records(char *buff, int len, int enable)
|
|
{
|
|
unsigned int search_len;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
unsigned long flag;
|
|
char *search;
|
|
int type;
|
|
int not;
|
|
|
|
flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
|
|
type = ftrace_setup_glob(buff, len, &search, ¬);
|
|
|
|
search_len = strlen(search);
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
|
|
if (rec->flags & FTRACE_FL_FAILED)
|
|
continue;
|
|
|
|
if (ftrace_match_record(rec, search, search_len, type)) {
|
|
if (not)
|
|
rec->flags &= ~flag;
|
|
else
|
|
rec->flags |= flag;
|
|
}
|
|
/*
|
|
* Only enable filtering if we have a function that
|
|
* is filtered on.
|
|
*/
|
|
if (enable && (rec->flags & FTRACE_FL_FILTER))
|
|
ftrace_filtered = 1;
|
|
} while_for_each_ftrace_rec();
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static int
|
|
ftrace_match_module_record(struct dyn_ftrace *rec, char *mod,
|
|
char *regex, int len, int type)
|
|
{
|
|
char str[KSYM_SYMBOL_LEN];
|
|
char *modname;
|
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
|
|
|
|
if (!modname || strcmp(modname, mod))
|
|
return 0;
|
|
|
|
/* blank search means to match all funcs in the mod */
|
|
if (len)
|
|
return ftrace_match(str, regex, len, type);
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
static void ftrace_match_module_records(char *buff, char *mod, int enable)
|
|
{
|
|
unsigned search_len = 0;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
int type = MATCH_FULL;
|
|
char *search = buff;
|
|
unsigned long flag;
|
|
int not = 0;
|
|
|
|
flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
|
|
|
|
/* blank or '*' mean the same */
|
|
if (strcmp(buff, "*") == 0)
|
|
buff[0] = 0;
|
|
|
|
/* handle the case of 'dont filter this module' */
|
|
if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
|
|
buff[0] = 0;
|
|
not = 1;
|
|
}
|
|
|
|
if (strlen(buff)) {
|
|
type = ftrace_setup_glob(buff, strlen(buff), &search, ¬);
|
|
search_len = strlen(search);
|
|
}
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
|
|
if (rec->flags & FTRACE_FL_FAILED)
|
|
continue;
|
|
|
|
if (ftrace_match_module_record(rec, mod,
|
|
search, search_len, type)) {
|
|
if (not)
|
|
rec->flags &= ~flag;
|
|
else
|
|
rec->flags |= flag;
|
|
}
|
|
if (enable && (rec->flags & FTRACE_FL_FILTER))
|
|
ftrace_filtered = 1;
|
|
|
|
} while_for_each_ftrace_rec();
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
/*
|
|
* We register the module command as a template to show others how
|
|
* to register the a command as well.
|
|
*/
|
|
|
|
static int
|
|
ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
|
|
{
|
|
char *mod;
|
|
|
|
/*
|
|
* cmd == 'mod' because we only registered this func
|
|
* for the 'mod' ftrace_func_command.
|
|
* But if you register one func with multiple commands,
|
|
* you can tell which command was used by the cmd
|
|
* parameter.
|
|
*/
|
|
|
|
/* we must have a module name */
|
|
if (!param)
|
|
return -EINVAL;
|
|
|
|
mod = strsep(¶m, ":");
|
|
if (!strlen(mod))
|
|
return -EINVAL;
|
|
|
|
ftrace_match_module_records(func, mod, enable);
|
|
return 0;
|
|
}
|
|
|
|
static struct ftrace_func_command ftrace_mod_cmd = {
|
|
.name = "mod",
|
|
.func = ftrace_mod_callback,
|
|
};
|
|
|
|
static int __init ftrace_mod_cmd_init(void)
|
|
{
|
|
return register_ftrace_command(&ftrace_mod_cmd);
|
|
}
|
|
device_initcall(ftrace_mod_cmd_init);
|
|
|
|
static void
|
|
function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct ftrace_func_probe *entry;
|
|
struct hlist_head *hhd;
|
|
struct hlist_node *n;
|
|
unsigned long key;
|
|
int resched;
|
|
|
|
key = hash_long(ip, FTRACE_HASH_BITS);
|
|
|
|
hhd = &ftrace_func_hash[key];
|
|
|
|
if (hlist_empty(hhd))
|
|
return;
|
|
|
|
/*
|
|
* Disable preemption for these calls to prevent a RCU grace
|
|
* period. This syncs the hash iteration and freeing of items
|
|
* on the hash. rcu_read_lock is too dangerous here.
|
|
*/
|
|
resched = ftrace_preempt_disable();
|
|
hlist_for_each_entry_rcu(entry, n, hhd, node) {
|
|
if (entry->ip == ip)
|
|
entry->ops->func(ip, parent_ip, &entry->data);
|
|
}
|
|
ftrace_preempt_enable(resched);
|
|
}
|
|
|
|
static struct ftrace_ops trace_probe_ops __read_mostly =
|
|
{
|
|
.func = function_trace_probe_call,
|
|
};
|
|
|
|
static int ftrace_probe_registered;
|
|
|
|
static void __enable_ftrace_function_probe(void)
|
|
{
|
|
int i;
|
|
|
|
if (ftrace_probe_registered)
|
|
return;
|
|
|
|
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
|
|
struct hlist_head *hhd = &ftrace_func_hash[i];
|
|
if (hhd->first)
|
|
break;
|
|
}
|
|
/* Nothing registered? */
|
|
if (i == FTRACE_FUNC_HASHSIZE)
|
|
return;
|
|
|
|
__register_ftrace_function(&trace_probe_ops);
|
|
ftrace_startup(0);
|
|
ftrace_probe_registered = 1;
|
|
}
|
|
|
|
static void __disable_ftrace_function_probe(void)
|
|
{
|
|
int i;
|
|
|
|
if (!ftrace_probe_registered)
|
|
return;
|
|
|
|
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
|
|
struct hlist_head *hhd = &ftrace_func_hash[i];
|
|
if (hhd->first)
|
|
return;
|
|
}
|
|
|
|
/* no more funcs left */
|
|
__unregister_ftrace_function(&trace_probe_ops);
|
|
ftrace_shutdown(0);
|
|
ftrace_probe_registered = 0;
|
|
}
|
|
|
|
|
|
static void ftrace_free_entry_rcu(struct rcu_head *rhp)
|
|
{
|
|
struct ftrace_func_probe *entry =
|
|
container_of(rhp, struct ftrace_func_probe, rcu);
|
|
|
|
if (entry->ops->free)
|
|
entry->ops->free(&entry->data);
|
|
kfree(entry);
|
|
}
|
|
|
|
|
|
int
|
|
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
|
|
void *data)
|
|
{
|
|
struct ftrace_func_probe *entry;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
int type, len, not;
|
|
unsigned long key;
|
|
int count = 0;
|
|
char *search;
|
|
|
|
type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
|
|
len = strlen(search);
|
|
|
|
/* we do not support '!' for function probes */
|
|
if (WARN_ON(not))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
|
|
if (rec->flags & FTRACE_FL_FAILED)
|
|
continue;
|
|
|
|
if (!ftrace_match_record(rec, search, len, type))
|
|
continue;
|
|
|
|
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (!entry) {
|
|
/* If we did not process any, then return error */
|
|
if (!count)
|
|
count = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
|
|
count++;
|
|
|
|
entry->data = data;
|
|
|
|
/*
|
|
* The caller might want to do something special
|
|
* for each function we find. We call the callback
|
|
* to give the caller an opportunity to do so.
|
|
*/
|
|
if (ops->callback) {
|
|
if (ops->callback(rec->ip, &entry->data) < 0) {
|
|
/* caller does not like this func */
|
|
kfree(entry);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
entry->ops = ops;
|
|
entry->ip = rec->ip;
|
|
|
|
key = hash_long(entry->ip, FTRACE_HASH_BITS);
|
|
hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
|
|
|
|
} while_for_each_ftrace_rec();
|
|
__enable_ftrace_function_probe();
|
|
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return count;
|
|
}
|
|
|
|
enum {
|
|
PROBE_TEST_FUNC = 1,
|
|
PROBE_TEST_DATA = 2
|
|
};
|
|
|
|
static void
|
|
__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
|
|
void *data, int flags)
|
|
{
|
|
struct ftrace_func_probe *entry;
|
|
struct hlist_node *n, *tmp;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
int type = MATCH_FULL;
|
|
int i, len = 0;
|
|
char *search;
|
|
|
|
if (glob && (strcmp(glob, "*") || !strlen(glob)))
|
|
glob = NULL;
|
|
else {
|
|
int not;
|
|
|
|
type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
|
|
len = strlen(search);
|
|
|
|
/* we do not support '!' for function probes */
|
|
if (WARN_ON(not))
|
|
return;
|
|
}
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
|
|
struct hlist_head *hhd = &ftrace_func_hash[i];
|
|
|
|
hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
|
|
|
|
/* break up if statements for readability */
|
|
if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
|
|
continue;
|
|
|
|
if ((flags & PROBE_TEST_DATA) && entry->data != data)
|
|
continue;
|
|
|
|
/* do this last, since it is the most expensive */
|
|
if (glob) {
|
|
kallsyms_lookup(entry->ip, NULL, NULL,
|
|
NULL, str);
|
|
if (!ftrace_match(str, glob, len, type))
|
|
continue;
|
|
}
|
|
|
|
hlist_del(&entry->node);
|
|
call_rcu(&entry->rcu, ftrace_free_entry_rcu);
|
|
}
|
|
}
|
|
__disable_ftrace_function_probe();
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
void
|
|
unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
|
|
void *data)
|
|
{
|
|
__unregister_ftrace_function_probe(glob, ops, data,
|
|
PROBE_TEST_FUNC | PROBE_TEST_DATA);
|
|
}
|
|
|
|
void
|
|
unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
|
|
{
|
|
__unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
|
|
}
|
|
|
|
void unregister_ftrace_function_probe_all(char *glob)
|
|
{
|
|
__unregister_ftrace_function_probe(glob, NULL, NULL, 0);
|
|
}
|
|
|
|
static LIST_HEAD(ftrace_commands);
|
|
static DEFINE_MUTEX(ftrace_cmd_mutex);
|
|
|
|
int register_ftrace_command(struct ftrace_func_command *cmd)
|
|
{
|
|
struct ftrace_func_command *p;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&ftrace_cmd_mutex);
|
|
list_for_each_entry(p, &ftrace_commands, list) {
|
|
if (strcmp(cmd->name, p->name) == 0) {
|
|
ret = -EBUSY;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
list_add(&cmd->list, &ftrace_commands);
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_cmd_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int unregister_ftrace_command(struct ftrace_func_command *cmd)
|
|
{
|
|
struct ftrace_func_command *p, *n;
|
|
int ret = -ENODEV;
|
|
|
|
mutex_lock(&ftrace_cmd_mutex);
|
|
list_for_each_entry_safe(p, n, &ftrace_commands, list) {
|
|
if (strcmp(cmd->name, p->name) == 0) {
|
|
ret = 0;
|
|
list_del_init(&p->list);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_cmd_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ftrace_process_regex(char *buff, int len, int enable)
|
|
{
|
|
char *func, *command, *next = buff;
|
|
struct ftrace_func_command *p;
|
|
int ret = -EINVAL;
|
|
|
|
func = strsep(&next, ":");
|
|
|
|
if (!next) {
|
|
ftrace_match_records(func, len, enable);
|
|
return 0;
|
|
}
|
|
|
|
/* command found */
|
|
|
|
command = strsep(&next, ":");
|
|
|
|
mutex_lock(&ftrace_cmd_mutex);
|
|
list_for_each_entry(p, &ftrace_commands, list) {
|
|
if (strcmp(p->name, command) == 0) {
|
|
ret = p->func(func, command, next, enable);
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
out_unlock:
|
|
mutex_unlock(&ftrace_cmd_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_regex_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos, int enable)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
char ch;
|
|
size_t read = 0;
|
|
ssize_t ret;
|
|
|
|
if (!cnt || cnt < 0)
|
|
return 0;
|
|
|
|
mutex_lock(&ftrace_regex_lock);
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
struct seq_file *m = file->private_data;
|
|
iter = m->private;
|
|
} else
|
|
iter = file->private_data;
|
|
|
|
if (!*ppos) {
|
|
iter->flags &= ~FTRACE_ITER_CONT;
|
|
iter->buffer_idx = 0;
|
|
}
|
|
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
|
|
/*
|
|
* If the parser haven't finished with the last write,
|
|
* continue reading the user input without skipping spaces.
|
|
*/
|
|
if (!(iter->flags & FTRACE_ITER_CONT)) {
|
|
/* skip white space */
|
|
while (cnt && isspace(ch)) {
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
|
|
/* only spaces were written */
|
|
if (isspace(ch)) {
|
|
*ppos += read;
|
|
ret = read;
|
|
goto out;
|
|
}
|
|
|
|
iter->buffer_idx = 0;
|
|
}
|
|
|
|
while (cnt && !isspace(ch)) {
|
|
if (iter->buffer_idx < FTRACE_BUFF_MAX)
|
|
iter->buffer[iter->buffer_idx++] = ch;
|
|
else {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
|
|
if (isspace(ch)) {
|
|
iter->filtered++;
|
|
iter->buffer[iter->buffer_idx] = 0;
|
|
ret = ftrace_process_regex(iter->buffer,
|
|
iter->buffer_idx, enable);
|
|
if (ret)
|
|
goto out;
|
|
iter->buffer_idx = 0;
|
|
} else {
|
|
iter->flags |= FTRACE_ITER_CONT;
|
|
iter->buffer[iter->buffer_idx++] = ch;
|
|
}
|
|
|
|
*ppos += read;
|
|
ret = read;
|
|
out:
|
|
mutex_unlock(&ftrace_regex_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_filter_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_notrace_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
|
|
}
|
|
|
|
static void
|
|
ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
|
|
{
|
|
if (unlikely(ftrace_disabled))
|
|
return;
|
|
|
|
mutex_lock(&ftrace_regex_lock);
|
|
if (reset)
|
|
ftrace_filter_reset(enable);
|
|
if (buf)
|
|
ftrace_match_records(buf, len, enable);
|
|
mutex_unlock(&ftrace_regex_lock);
|
|
}
|
|
|
|
/**
|
|
* ftrace_set_filter - set a function to filter on in ftrace
|
|
* @buf - the string that holds the function filter text.
|
|
* @len - the length of the string.
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Filters denote which functions should be enabled when tracing is enabled.
|
|
* If @buf is NULL and reset is set, all functions will be enabled for tracing.
|
|
*/
|
|
void ftrace_set_filter(unsigned char *buf, int len, int reset)
|
|
{
|
|
ftrace_set_regex(buf, len, reset, 1);
|
|
}
|
|
|
|
/**
|
|
* ftrace_set_notrace - set a function to not trace in ftrace
|
|
* @buf - the string that holds the function notrace text.
|
|
* @len - the length of the string.
|
|
* @reset - non zero to reset all filters before applying this filter.
|
|
*
|
|
* Notrace Filters denote which functions should not be enabled when tracing
|
|
* is enabled. If @buf is NULL and reset is set, all functions will be enabled
|
|
* for tracing.
|
|
*/
|
|
void ftrace_set_notrace(unsigned char *buf, int len, int reset)
|
|
{
|
|
ftrace_set_regex(buf, len, reset, 0);
|
|
}
|
|
|
|
/*
|
|
* command line interface to allow users to set filters on boot up.
|
|
*/
|
|
#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
|
|
static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
|
|
static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
|
|
|
|
static int __init set_ftrace_notrace(char *str)
|
|
{
|
|
strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
|
|
return 1;
|
|
}
|
|
__setup("ftrace_notrace=", set_ftrace_notrace);
|
|
|
|
static int __init set_ftrace_filter(char *str)
|
|
{
|
|
strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
|
|
return 1;
|
|
}
|
|
__setup("ftrace_filter=", set_ftrace_filter);
|
|
|
|
static void __init set_ftrace_early_filter(char *buf, int enable)
|
|
{
|
|
char *func;
|
|
|
|
while (buf) {
|
|
func = strsep(&buf, ",");
|
|
ftrace_set_regex(func, strlen(func), 0, enable);
|
|
}
|
|
}
|
|
|
|
static void __init set_ftrace_early_filters(void)
|
|
{
|
|
if (ftrace_filter_buf[0])
|
|
set_ftrace_early_filter(ftrace_filter_buf, 1);
|
|
if (ftrace_notrace_buf[0])
|
|
set_ftrace_early_filter(ftrace_notrace_buf, 0);
|
|
}
|
|
|
|
static int
|
|
ftrace_regex_release(struct inode *inode, struct file *file, int enable)
|
|
{
|
|
struct seq_file *m = (struct seq_file *)file->private_data;
|
|
struct ftrace_iterator *iter;
|
|
|
|
mutex_lock(&ftrace_regex_lock);
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter = m->private;
|
|
|
|
seq_release(inode, file);
|
|
} else
|
|
iter = file->private_data;
|
|
|
|
if (iter->buffer_idx) {
|
|
iter->filtered++;
|
|
iter->buffer[iter->buffer_idx] = 0;
|
|
ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
|
|
}
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
if (ftrace_start_up && ftrace_enabled)
|
|
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
kfree(iter);
|
|
mutex_unlock(&ftrace_regex_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_filter_release(struct inode *inode, struct file *file)
|
|
{
|
|
return ftrace_regex_release(inode, file, 1);
|
|
}
|
|
|
|
static int
|
|
ftrace_notrace_release(struct inode *inode, struct file *file)
|
|
{
|
|
return ftrace_regex_release(inode, file, 0);
|
|
}
|
|
|
|
static const struct file_operations ftrace_avail_fops = {
|
|
.open = ftrace_avail_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = ftrace_avail_release,
|
|
};
|
|
|
|
static const struct file_operations ftrace_failures_fops = {
|
|
.open = ftrace_failures_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = ftrace_avail_release,
|
|
};
|
|
|
|
static const struct file_operations ftrace_filter_fops = {
|
|
.open = ftrace_filter_open,
|
|
.read = seq_read,
|
|
.write = ftrace_filter_write,
|
|
.llseek = ftrace_regex_lseek,
|
|
.release = ftrace_filter_release,
|
|
};
|
|
|
|
static const struct file_operations ftrace_notrace_fops = {
|
|
.open = ftrace_notrace_open,
|
|
.read = seq_read,
|
|
.write = ftrace_notrace_write,
|
|
.llseek = ftrace_regex_lseek,
|
|
.release = ftrace_notrace_release,
|
|
};
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
static DEFINE_MUTEX(graph_lock);
|
|
|
|
int ftrace_graph_count;
|
|
unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
|
|
|
|
static void *
|
|
__g_next(struct seq_file *m, loff_t *pos)
|
|
{
|
|
unsigned long *array = m->private;
|
|
|
|
if (*pos >= ftrace_graph_count)
|
|
return NULL;
|
|
return &array[*pos];
|
|
}
|
|
|
|
static void *
|
|
g_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
(*pos)++;
|
|
return __g_next(m, pos);
|
|
}
|
|
|
|
static void *g_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&graph_lock);
|
|
|
|
/* Nothing, tell g_show to print all functions are enabled */
|
|
if (!ftrace_graph_count && !*pos)
|
|
return (void *)1;
|
|
|
|
return __g_next(m, pos);
|
|
}
|
|
|
|
static void g_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&graph_lock);
|
|
}
|
|
|
|
static int g_show(struct seq_file *m, void *v)
|
|
{
|
|
unsigned long *ptr = v;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
if (!ptr)
|
|
return 0;
|
|
|
|
if (ptr == (unsigned long *)1) {
|
|
seq_printf(m, "#### all functions enabled ####\n");
|
|
return 0;
|
|
}
|
|
|
|
kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
|
|
|
|
seq_printf(m, "%s\n", str);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations ftrace_graph_seq_ops = {
|
|
.start = g_start,
|
|
.next = g_next,
|
|
.stop = g_stop,
|
|
.show = g_show,
|
|
};
|
|
|
|
static int
|
|
ftrace_graph_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&graph_lock);
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC)) {
|
|
ftrace_graph_count = 0;
|
|
memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
|
|
}
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
ret = seq_open(file, &ftrace_graph_seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = ftrace_graph_funcs;
|
|
}
|
|
} else
|
|
file->private_data = ftrace_graph_funcs;
|
|
mutex_unlock(&graph_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
ftrace_graph_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (file->f_mode & FMODE_READ)
|
|
seq_release(inode, file);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_set_func(unsigned long *array, int *idx, char *buffer)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
struct ftrace_page *pg;
|
|
int search_len;
|
|
int found = 0;
|
|
int type, not;
|
|
char *search;
|
|
bool exists;
|
|
int i;
|
|
|
|
if (ftrace_disabled)
|
|
return -ENODEV;
|
|
|
|
/* decode regex */
|
|
type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬);
|
|
if (not)
|
|
return -EINVAL;
|
|
|
|
search_len = strlen(search);
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
|
|
if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
|
|
break;
|
|
|
|
if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
|
|
continue;
|
|
|
|
if (ftrace_match_record(rec, search, search_len, type)) {
|
|
/* ensure it is not already in the array */
|
|
exists = false;
|
|
for (i = 0; i < *idx; i++)
|
|
if (array[i] == rec->ip) {
|
|
exists = true;
|
|
break;
|
|
}
|
|
if (!exists) {
|
|
array[(*idx)++] = rec->ip;
|
|
found = 1;
|
|
}
|
|
}
|
|
} while_for_each_ftrace_rec();
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return found ? 0 : -EINVAL;
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_graph_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned char buffer[FTRACE_BUFF_MAX+1];
|
|
unsigned long *array;
|
|
size_t read = 0;
|
|
ssize_t ret;
|
|
int index = 0;
|
|
char ch;
|
|
|
|
if (!cnt || cnt < 0)
|
|
return 0;
|
|
|
|
mutex_lock(&graph_lock);
|
|
|
|
if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
struct seq_file *m = file->private_data;
|
|
array = m->private;
|
|
} else
|
|
array = file->private_data;
|
|
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
|
|
/* skip white space */
|
|
while (cnt && isspace(ch)) {
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
|
|
if (isspace(ch)) {
|
|
*ppos += read;
|
|
ret = read;
|
|
goto out;
|
|
}
|
|
|
|
while (cnt && !isspace(ch)) {
|
|
if (index < FTRACE_BUFF_MAX)
|
|
buffer[index++] = ch;
|
|
else {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
buffer[index] = 0;
|
|
|
|
/* we allow only one expression at a time */
|
|
ret = ftrace_set_func(array, &ftrace_graph_count, buffer);
|
|
if (ret)
|
|
goto out;
|
|
|
|
file->f_pos += read;
|
|
|
|
ret = read;
|
|
out:
|
|
mutex_unlock(&graph_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations ftrace_graph_fops = {
|
|
.open = ftrace_graph_open,
|
|
.read = seq_read,
|
|
.write = ftrace_graph_write,
|
|
.release = ftrace_graph_release,
|
|
};
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
|
|
{
|
|
|
|
trace_create_file("available_filter_functions", 0444,
|
|
d_tracer, NULL, &ftrace_avail_fops);
|
|
|
|
trace_create_file("failures", 0444,
|
|
d_tracer, NULL, &ftrace_failures_fops);
|
|
|
|
trace_create_file("set_ftrace_filter", 0644, d_tracer,
|
|
NULL, &ftrace_filter_fops);
|
|
|
|
trace_create_file("set_ftrace_notrace", 0644, d_tracer,
|
|
NULL, &ftrace_notrace_fops);
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
trace_create_file("set_graph_function", 0444, d_tracer,
|
|
NULL,
|
|
&ftrace_graph_fops);
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_convert_nops(struct module *mod,
|
|
unsigned long *start,
|
|
unsigned long *end)
|
|
{
|
|
unsigned long *p;
|
|
unsigned long addr;
|
|
unsigned long flags;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
p = start;
|
|
while (p < end) {
|
|
addr = ftrace_call_adjust(*p++);
|
|
/*
|
|
* Some architecture linkers will pad between
|
|
* the different mcount_loc sections of different
|
|
* object files to satisfy alignments.
|
|
* Skip any NULL pointers.
|
|
*/
|
|
if (!addr)
|
|
continue;
|
|
ftrace_record_ip(addr);
|
|
}
|
|
|
|
/* disable interrupts to prevent kstop machine */
|
|
local_irq_save(flags);
|
|
ftrace_update_code(mod);
|
|
local_irq_restore(flags);
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_MODULES
|
|
void ftrace_release(void *start, void *end)
|
|
{
|
|
struct dyn_ftrace *rec;
|
|
struct ftrace_page *pg;
|
|
unsigned long s = (unsigned long)start;
|
|
unsigned long e = (unsigned long)end;
|
|
|
|
if (ftrace_disabled || !start || start == end)
|
|
return;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
do_for_each_ftrace_rec(pg, rec) {
|
|
if ((rec->ip >= s) && (rec->ip < e)) {
|
|
/*
|
|
* rec->ip is changed in ftrace_free_rec()
|
|
* It should not between s and e if record was freed.
|
|
*/
|
|
FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
|
|
ftrace_free_rec(rec);
|
|
}
|
|
} while_for_each_ftrace_rec();
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
static void ftrace_init_module(struct module *mod,
|
|
unsigned long *start, unsigned long *end)
|
|
{
|
|
if (ftrace_disabled || start == end)
|
|
return;
|
|
ftrace_convert_nops(mod, start, end);
|
|
}
|
|
|
|
static int ftrace_module_notify(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct module *mod = data;
|
|
|
|
switch (val) {
|
|
case MODULE_STATE_COMING:
|
|
ftrace_init_module(mod, mod->ftrace_callsites,
|
|
mod->ftrace_callsites +
|
|
mod->num_ftrace_callsites);
|
|
break;
|
|
case MODULE_STATE_GOING:
|
|
ftrace_release(mod->ftrace_callsites,
|
|
mod->ftrace_callsites +
|
|
mod->num_ftrace_callsites);
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
static int ftrace_module_notify(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_MODULES */
|
|
|
|
struct notifier_block ftrace_module_nb = {
|
|
.notifier_call = ftrace_module_notify,
|
|
.priority = 0,
|
|
};
|
|
|
|
extern unsigned long __start_mcount_loc[];
|
|
extern unsigned long __stop_mcount_loc[];
|
|
|
|
void __init ftrace_init(void)
|
|
{
|
|
unsigned long count, addr, flags;
|
|
int ret;
|
|
|
|
/* Keep the ftrace pointer to the stub */
|
|
addr = (unsigned long)ftrace_stub;
|
|
|
|
local_irq_save(flags);
|
|
ftrace_dyn_arch_init(&addr);
|
|
local_irq_restore(flags);
|
|
|
|
/* ftrace_dyn_arch_init places the return code in addr */
|
|
if (addr)
|
|
goto failed;
|
|
|
|
count = __stop_mcount_loc - __start_mcount_loc;
|
|
|
|
ret = ftrace_dyn_table_alloc(count);
|
|
if (ret)
|
|
goto failed;
|
|
|
|
last_ftrace_enabled = ftrace_enabled = 1;
|
|
|
|
ret = ftrace_convert_nops(NULL,
|
|
__start_mcount_loc,
|
|
__stop_mcount_loc);
|
|
|
|
ret = register_module_notifier(&ftrace_module_nb);
|
|
if (ret)
|
|
pr_warning("Failed to register trace ftrace module notifier\n");
|
|
|
|
set_ftrace_early_filters();
|
|
|
|
return;
|
|
failed:
|
|
ftrace_disabled = 1;
|
|
}
|
|
|
|
#else
|
|
|
|
static int __init ftrace_nodyn_init(void)
|
|
{
|
|
ftrace_enabled = 1;
|
|
return 0;
|
|
}
|
|
device_initcall(ftrace_nodyn_init);
|
|
|
|
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
|
|
static inline void ftrace_startup_enable(int command) { }
|
|
/* Keep as macros so we do not need to define the commands */
|
|
# define ftrace_startup(command) do { } while (0)
|
|
# define ftrace_shutdown(command) do { } while (0)
|
|
# define ftrace_startup_sysctl() do { } while (0)
|
|
# define ftrace_shutdown_sysctl() do { } while (0)
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
static ssize_t
|
|
ftrace_pid_read(struct file *file, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64];
|
|
int r;
|
|
|
|
if (ftrace_pid_trace == ftrace_swapper_pid)
|
|
r = sprintf(buf, "swapper tasks\n");
|
|
else if (ftrace_pid_trace)
|
|
r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace));
|
|
else
|
|
r = sprintf(buf, "no pid\n");
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static void clear_ftrace_swapper(void)
|
|
{
|
|
struct task_struct *p;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu) {
|
|
p = idle_task(cpu);
|
|
clear_tsk_trace_trace(p);
|
|
}
|
|
put_online_cpus();
|
|
}
|
|
|
|
static void set_ftrace_swapper(void)
|
|
{
|
|
struct task_struct *p;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu) {
|
|
p = idle_task(cpu);
|
|
set_tsk_trace_trace(p);
|
|
}
|
|
put_online_cpus();
|
|
}
|
|
|
|
static void clear_ftrace_pid(struct pid *pid)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
rcu_read_lock();
|
|
do_each_pid_task(pid, PIDTYPE_PID, p) {
|
|
clear_tsk_trace_trace(p);
|
|
} while_each_pid_task(pid, PIDTYPE_PID, p);
|
|
rcu_read_unlock();
|
|
|
|
put_pid(pid);
|
|
}
|
|
|
|
static void set_ftrace_pid(struct pid *pid)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
rcu_read_lock();
|
|
do_each_pid_task(pid, PIDTYPE_PID, p) {
|
|
set_tsk_trace_trace(p);
|
|
} while_each_pid_task(pid, PIDTYPE_PID, p);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void clear_ftrace_pid_task(struct pid **pid)
|
|
{
|
|
if (*pid == ftrace_swapper_pid)
|
|
clear_ftrace_swapper();
|
|
else
|
|
clear_ftrace_pid(*pid);
|
|
|
|
*pid = NULL;
|
|
}
|
|
|
|
static void set_ftrace_pid_task(struct pid *pid)
|
|
{
|
|
if (pid == ftrace_swapper_pid)
|
|
set_ftrace_swapper();
|
|
else
|
|
set_ftrace_pid(pid);
|
|
}
|
|
|
|
static ssize_t
|
|
ftrace_pid_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct pid *pid;
|
|
char buf[64];
|
|
long val;
|
|
int ret;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
ret = strict_strtol(buf, 10, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
if (val < 0) {
|
|
/* disable pid tracing */
|
|
if (!ftrace_pid_trace)
|
|
goto out;
|
|
|
|
clear_ftrace_pid_task(&ftrace_pid_trace);
|
|
|
|
} else {
|
|
/* swapper task is special */
|
|
if (!val) {
|
|
pid = ftrace_swapper_pid;
|
|
if (pid == ftrace_pid_trace)
|
|
goto out;
|
|
} else {
|
|
pid = find_get_pid(val);
|
|
|
|
if (pid == ftrace_pid_trace) {
|
|
put_pid(pid);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (ftrace_pid_trace)
|
|
clear_ftrace_pid_task(&ftrace_pid_trace);
|
|
|
|
if (!pid)
|
|
goto out;
|
|
|
|
ftrace_pid_trace = pid;
|
|
|
|
set_ftrace_pid_task(ftrace_pid_trace);
|
|
}
|
|
|
|
/* update the function call */
|
|
ftrace_update_pid_func();
|
|
ftrace_startup_enable(0);
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static const struct file_operations ftrace_pid_fops = {
|
|
.read = ftrace_pid_read,
|
|
.write = ftrace_pid_write,
|
|
};
|
|
|
|
static __init int ftrace_init_debugfs(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
ftrace_init_dyn_debugfs(d_tracer);
|
|
|
|
trace_create_file("set_ftrace_pid", 0644, d_tracer,
|
|
NULL, &ftrace_pid_fops);
|
|
|
|
ftrace_profile_debugfs(d_tracer);
|
|
|
|
return 0;
|
|
}
|
|
fs_initcall(ftrace_init_debugfs);
|
|
|
|
/**
|
|
* ftrace_kill - kill ftrace
|
|
*
|
|
* This function should be used by panic code. It stops ftrace
|
|
* but in a not so nice way. If you need to simply kill ftrace
|
|
* from a non-atomic section, use ftrace_kill.
|
|
*/
|
|
void ftrace_kill(void)
|
|
{
|
|
ftrace_disabled = 1;
|
|
ftrace_enabled = 0;
|
|
clear_ftrace_function();
|
|
}
|
|
|
|
/**
|
|
* register_ftrace_function - register a function for profiling
|
|
* @ops - ops structure that holds the function for profiling.
|
|
*
|
|
* Register a function to be called by all functions in the
|
|
* kernel.
|
|
*
|
|
* Note: @ops->func and all the functions it calls must be labeled
|
|
* with "notrace", otherwise it will go into a
|
|
* recursive loop.
|
|
*/
|
|
int register_ftrace_function(struct ftrace_ops *ops)
|
|
{
|
|
int ret;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -1;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
ret = __register_ftrace_function(ops);
|
|
ftrace_startup(0);
|
|
|
|
mutex_unlock(&ftrace_lock);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* unregister_ftrace_function - unregister a function for profiling.
|
|
* @ops - ops structure that holds the function to unregister
|
|
*
|
|
* Unregister a function that was added to be called by ftrace profiling.
|
|
*/
|
|
int unregister_ftrace_function(struct ftrace_ops *ops)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
ret = __unregister_ftrace_function(ops);
|
|
ftrace_shutdown(0);
|
|
mutex_unlock(&ftrace_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
ftrace_enable_sysctl(struct ctl_table *table, int write,
|
|
struct file *file, void __user *buffer, size_t *lenp,
|
|
loff_t *ppos)
|
|
{
|
|
int ret;
|
|
|
|
if (unlikely(ftrace_disabled))
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
|
|
|
|
if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
|
|
goto out;
|
|
|
|
last_ftrace_enabled = !!ftrace_enabled;
|
|
|
|
if (ftrace_enabled) {
|
|
|
|
ftrace_startup_sysctl();
|
|
|
|
/* we are starting ftrace again */
|
|
if (ftrace_list != &ftrace_list_end) {
|
|
if (ftrace_list->next == &ftrace_list_end)
|
|
ftrace_trace_function = ftrace_list->func;
|
|
else
|
|
ftrace_trace_function = ftrace_list_func;
|
|
}
|
|
|
|
} else {
|
|
/* stopping ftrace calls (just send to ftrace_stub) */
|
|
ftrace_trace_function = ftrace_stub;
|
|
|
|
ftrace_shutdown_sysctl();
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
static int ftrace_graph_active;
|
|
static struct notifier_block ftrace_suspend_notifier;
|
|
|
|
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* The callbacks that hook a function */
|
|
trace_func_graph_ret_t ftrace_graph_return =
|
|
(trace_func_graph_ret_t)ftrace_stub;
|
|
trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
|
|
|
|
/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
|
|
static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
|
|
{
|
|
int i;
|
|
int ret = 0;
|
|
unsigned long flags;
|
|
int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
|
|
struct task_struct *g, *t;
|
|
|
|
for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
|
|
ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
|
|
* sizeof(struct ftrace_ret_stack),
|
|
GFP_KERNEL);
|
|
if (!ret_stack_list[i]) {
|
|
start = 0;
|
|
end = i;
|
|
ret = -ENOMEM;
|
|
goto free;
|
|
}
|
|
}
|
|
|
|
read_lock_irqsave(&tasklist_lock, flags);
|
|
do_each_thread(g, t) {
|
|
if (start == end) {
|
|
ret = -EAGAIN;
|
|
goto unlock;
|
|
}
|
|
|
|
if (t->ret_stack == NULL) {
|
|
atomic_set(&t->tracing_graph_pause, 0);
|
|
atomic_set(&t->trace_overrun, 0);
|
|
t->curr_ret_stack = -1;
|
|
/* Make sure the tasks see the -1 first: */
|
|
smp_wmb();
|
|
t->ret_stack = ret_stack_list[start++];
|
|
}
|
|
} while_each_thread(g, t);
|
|
|
|
unlock:
|
|
read_unlock_irqrestore(&tasklist_lock, flags);
|
|
free:
|
|
for (i = start; i < end; i++)
|
|
kfree(ret_stack_list[i]);
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev,
|
|
struct task_struct *next)
|
|
{
|
|
unsigned long long timestamp;
|
|
int index;
|
|
|
|
/*
|
|
* Does the user want to count the time a function was asleep.
|
|
* If so, do not update the time stamps.
|
|
*/
|
|
if (trace_flags & TRACE_ITER_SLEEP_TIME)
|
|
return;
|
|
|
|
timestamp = trace_clock_local();
|
|
|
|
prev->ftrace_timestamp = timestamp;
|
|
|
|
/* only process tasks that we timestamped */
|
|
if (!next->ftrace_timestamp)
|
|
return;
|
|
|
|
/*
|
|
* Update all the counters in next to make up for the
|
|
* time next was sleeping.
|
|
*/
|
|
timestamp -= next->ftrace_timestamp;
|
|
|
|
for (index = next->curr_ret_stack; index >= 0; index--)
|
|
next->ret_stack[index].calltime += timestamp;
|
|
}
|
|
|
|
/* Allocate a return stack for each task */
|
|
static int start_graph_tracing(void)
|
|
{
|
|
struct ftrace_ret_stack **ret_stack_list;
|
|
int ret, cpu;
|
|
|
|
ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
|
|
sizeof(struct ftrace_ret_stack *),
|
|
GFP_KERNEL);
|
|
|
|
if (!ret_stack_list)
|
|
return -ENOMEM;
|
|
|
|
/* The cpu_boot init_task->ret_stack will never be freed */
|
|
for_each_online_cpu(cpu) {
|
|
if (!idle_task(cpu)->ret_stack)
|
|
ftrace_graph_init_task(idle_task(cpu));
|
|
}
|
|
|
|
do {
|
|
ret = alloc_retstack_tasklist(ret_stack_list);
|
|
} while (ret == -EAGAIN);
|
|
|
|
if (!ret) {
|
|
ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch);
|
|
if (ret)
|
|
pr_info("ftrace_graph: Couldn't activate tracepoint"
|
|
" probe to kernel_sched_switch\n");
|
|
}
|
|
|
|
kfree(ret_stack_list);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Hibernation protection.
|
|
* The state of the current task is too much unstable during
|
|
* suspend/restore to disk. We want to protect against that.
|
|
*/
|
|
static int
|
|
ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
|
|
void *unused)
|
|
{
|
|
switch (state) {
|
|
case PM_HIBERNATION_PREPARE:
|
|
pause_graph_tracing();
|
|
break;
|
|
|
|
case PM_POST_HIBERNATION:
|
|
unpause_graph_tracing();
|
|
break;
|
|
}
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
int register_ftrace_graph(trace_func_graph_ret_t retfunc,
|
|
trace_func_graph_ent_t entryfunc)
|
|
{
|
|
int ret = 0;
|
|
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
/* we currently allow only one tracer registered at a time */
|
|
if (ftrace_graph_active) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
|
|
register_pm_notifier(&ftrace_suspend_notifier);
|
|
|
|
ftrace_graph_active++;
|
|
ret = start_graph_tracing();
|
|
if (ret) {
|
|
ftrace_graph_active--;
|
|
goto out;
|
|
}
|
|
|
|
ftrace_graph_return = retfunc;
|
|
ftrace_graph_entry = entryfunc;
|
|
|
|
ftrace_startup(FTRACE_START_FUNC_RET);
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
return ret;
|
|
}
|
|
|
|
void unregister_ftrace_graph(void)
|
|
{
|
|
mutex_lock(&ftrace_lock);
|
|
|
|
if (unlikely(!ftrace_graph_active))
|
|
goto out;
|
|
|
|
ftrace_graph_active--;
|
|
unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
|
|
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
|
|
ftrace_graph_entry = ftrace_graph_entry_stub;
|
|
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
|
|
unregister_pm_notifier(&ftrace_suspend_notifier);
|
|
|
|
out:
|
|
mutex_unlock(&ftrace_lock);
|
|
}
|
|
|
|
/* Allocate a return stack for newly created task */
|
|
void ftrace_graph_init_task(struct task_struct *t)
|
|
{
|
|
/* Make sure we do not use the parent ret_stack */
|
|
t->ret_stack = NULL;
|
|
|
|
if (ftrace_graph_active) {
|
|
struct ftrace_ret_stack *ret_stack;
|
|
|
|
ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
|
|
* sizeof(struct ftrace_ret_stack),
|
|
GFP_KERNEL);
|
|
if (!ret_stack)
|
|
return;
|
|
t->curr_ret_stack = -1;
|
|
atomic_set(&t->tracing_graph_pause, 0);
|
|
atomic_set(&t->trace_overrun, 0);
|
|
t->ftrace_timestamp = 0;
|
|
/* make curr_ret_stack visable before we add the ret_stack */
|
|
smp_wmb();
|
|
t->ret_stack = ret_stack;
|
|
}
|
|
}
|
|
|
|
void ftrace_graph_exit_task(struct task_struct *t)
|
|
{
|
|
struct ftrace_ret_stack *ret_stack = t->ret_stack;
|
|
|
|
t->ret_stack = NULL;
|
|
/* NULL must become visible to IRQs before we free it: */
|
|
barrier();
|
|
|
|
kfree(ret_stack);
|
|
}
|
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void ftrace_graph_stop(void)
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|
{
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|
ftrace_stop();
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|
}
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|
#endif
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|