![Steven Rostedt](/assets/img/avatar_default.png)
When the function graph tracer is enabled, it calls the initialization needed for the init tasks that would be called on all created tasks. The problem is that this is called every time the function graph tracer is enabled, and the ret_stack is allocated for the idle tasks each time. Thus, the old ret_stack is lost and a memory leak is created. This is also dangerous because if an interrupt happened on another CPU with the init task and the ret_stack is replaced, we then lose all the return pointers for the interrupt, and a crash would take place. [ Impact: fix memory leak and possible crash due to race ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2772 lines
57 KiB
C
2772 lines
57 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/sched.h>
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#include <asm/ftrace.h>
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#include "trace.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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/* set when tracing only a pid */
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struct pid *ftrace_pid_trace;
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static struct pid * const ftrace_swapper_pid = &init_struct_pid;
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#ifdef CONFIG_DYNAMIC_FTRACE
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#ifndef CONFIG_FTRACE_MCOUNT_RECORD
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# error Dynamic ftrace depends on MCOUNT_RECORD
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#endif
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static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
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struct ftrace_func_probe {
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struct hlist_node node;
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struct ftrace_probe_ops *ops;
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unsigned long flags;
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unsigned long ip;
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void *data;
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struct rcu_head rcu;
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};
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enum {
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FTRACE_ENABLE_CALLS = (1 << 0),
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FTRACE_DISABLE_CALLS = (1 << 1),
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FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
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FTRACE_ENABLE_MCOUNT = (1 << 3),
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FTRACE_DISABLE_MCOUNT = (1 << 4),
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FTRACE_START_FUNC_RET = (1 << 5),
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FTRACE_STOP_FUNC_RET = (1 << 6),
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};
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static int ftrace_filtered;
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static struct dyn_ftrace *ftrace_new_addrs;
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static DEFINE_MUTEX(ftrace_regex_lock);
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struct ftrace_page {
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struct ftrace_page *next;
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int index;
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struct dyn_ftrace records[];
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};
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#define ENTRIES_PER_PAGE \
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((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
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/* estimate from running different kernels */
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#define NR_TO_INIT 10000
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static struct ftrace_page *ftrace_pages_start;
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static struct ftrace_page *ftrace_pages;
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static struct dyn_ftrace *ftrace_free_records;
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/*
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* This is a double for. Do not use 'break' to break out of the loop,
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* you must use a goto.
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*/
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#define do_for_each_ftrace_rec(pg, rec) \
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for (pg = ftrace_pages_start; pg; pg = pg->next) { \
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int _____i; \
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for (_____i = 0; _____i < pg->index; _____i++) { \
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rec = &pg->records[_____i];
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#define while_for_each_ftrace_rec() \
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} \
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}
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#ifdef CONFIG_KPROBES
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static int frozen_record_count;
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static inline void freeze_record(struct dyn_ftrace *rec)
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{
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if (!(rec->flags & FTRACE_FL_FROZEN)) {
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rec->flags |= FTRACE_FL_FROZEN;
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frozen_record_count++;
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}
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}
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static inline void unfreeze_record(struct dyn_ftrace *rec)
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{
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if (rec->flags & FTRACE_FL_FROZEN) {
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rec->flags &= ~FTRACE_FL_FROZEN;
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frozen_record_count--;
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}
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}
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static inline int record_frozen(struct dyn_ftrace *rec)
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{
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return rec->flags & FTRACE_FL_FROZEN;
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}
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#else
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# define freeze_record(rec) ({ 0; })
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# define unfreeze_record(rec) ({ 0; })
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# define record_frozen(rec) ({ 0; })
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#endif /* CONFIG_KPROBES */
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static void ftrace_free_rec(struct dyn_ftrace *rec)
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{
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rec->freelist = ftrace_free_records;
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ftrace_free_records = rec;
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rec->flags |= FTRACE_FL_FREE;
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}
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void ftrace_release(void *start, unsigned long size)
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{
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struct dyn_ftrace *rec;
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struct ftrace_page *pg;
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unsigned long s = (unsigned long)start;
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unsigned long e = s + size;
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if (ftrace_disabled || !start)
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return;
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mutex_lock(&ftrace_lock);
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do_for_each_ftrace_rec(pg, rec) {
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if ((rec->ip >= s) && (rec->ip < e)) {
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/*
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* rec->ip is changed in ftrace_free_rec()
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* It should not between s and e if record was freed.
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*/
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FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
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ftrace_free_rec(rec);
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}
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} while_for_each_ftrace_rec();
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mutex_unlock(&ftrace_lock);
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}
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static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
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{
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struct dyn_ftrace *rec;
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/* First check for freed records */
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if (ftrace_free_records) {
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rec = ftrace_free_records;
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if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
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FTRACE_WARN_ON_ONCE(1);
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ftrace_free_records = NULL;
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return NULL;
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}
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ftrace_free_records = rec->freelist;
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memset(rec, 0, sizeof(*rec));
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return rec;
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}
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if (ftrace_pages->index == ENTRIES_PER_PAGE) {
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if (!ftrace_pages->next) {
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/* allocate another page */
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ftrace_pages->next =
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(void *)get_zeroed_page(GFP_KERNEL);
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if (!ftrace_pages->next)
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return NULL;
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}
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ftrace_pages = ftrace_pages->next;
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}
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return &ftrace_pages->records[ftrace_pages->index++];
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}
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static struct dyn_ftrace *
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ftrace_record_ip(unsigned long ip)
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{
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struct dyn_ftrace *rec;
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if (ftrace_disabled)
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return NULL;
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rec = ftrace_alloc_dyn_node(ip);
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if (!rec)
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return NULL;
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rec->ip = ip;
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rec->newlist = ftrace_new_addrs;
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ftrace_new_addrs = rec;
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return rec;
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}
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static void print_ip_ins(const char *fmt, unsigned char *p)
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{
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int i;
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printk(KERN_CONT "%s", fmt);
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for (i = 0; i < MCOUNT_INSN_SIZE; i++)
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printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
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}
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static void ftrace_bug(int failed, unsigned long ip)
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{
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switch (failed) {
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case -EFAULT:
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FTRACE_WARN_ON_ONCE(1);
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pr_info("ftrace faulted on modifying ");
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print_ip_sym(ip);
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break;
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case -EINVAL:
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FTRACE_WARN_ON_ONCE(1);
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pr_info("ftrace failed to modify ");
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print_ip_sym(ip);
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print_ip_ins(" actual: ", (unsigned char *)ip);
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printk(KERN_CONT "\n");
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break;
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case -EPERM:
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FTRACE_WARN_ON_ONCE(1);
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pr_info("ftrace faulted on writing ");
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print_ip_sym(ip);
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break;
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default:
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FTRACE_WARN_ON_ONCE(1);
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pr_info("ftrace faulted on unknown error ");
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print_ip_sym(ip);
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}
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}
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static int
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__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
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{
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unsigned long ftrace_addr;
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unsigned long ip, fl;
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ftrace_addr = (unsigned long)FTRACE_ADDR;
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ip = rec->ip;
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/*
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* If this record is not to be traced and
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* it is not enabled then do nothing.
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*
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* If this record is not to be traced and
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* it is enabled then disable it.
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*
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*/
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if (rec->flags & FTRACE_FL_NOTRACE) {
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if (rec->flags & FTRACE_FL_ENABLED)
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rec->flags &= ~FTRACE_FL_ENABLED;
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else
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return 0;
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|
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} else if (ftrace_filtered && enable) {
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/*
|
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* Filtering is on:
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*/
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fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
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/* Record is filtered and enabled, do nothing */
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if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
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return 0;
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|
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/* Record is not filtered or enabled, do nothing */
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if (!fl)
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return 0;
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/* Record is not filtered but enabled, disable it */
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if (fl == FTRACE_FL_ENABLED)
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rec->flags &= ~FTRACE_FL_ENABLED;
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else
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/* Otherwise record is filtered but not enabled, enable it */
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rec->flags |= FTRACE_FL_ENABLED;
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} else {
|
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/* Disable or not filtered */
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|
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if (enable) {
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/* if record is enabled, do nothing */
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if (rec->flags & FTRACE_FL_ENABLED)
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return 0;
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rec->flags |= FTRACE_FL_ENABLED;
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} else {
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|
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/* if record is not enabled, do nothing */
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if (!(rec->flags & FTRACE_FL_ENABLED))
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return 0;
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|
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rec->flags &= ~FTRACE_FL_ENABLED;
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}
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}
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|
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if (rec->flags & FTRACE_FL_ENABLED)
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return ftrace_make_call(rec, ftrace_addr);
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else
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return ftrace_make_nop(NULL, rec, ftrace_addr);
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}
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|
|
static void ftrace_replace_code(int enable)
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{
|
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struct dyn_ftrace *rec;
|
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struct ftrace_page *pg;
|
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int failed;
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|
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do_for_each_ftrace_rec(pg, rec) {
|
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/*
|
|
* Skip over free records, records that have
|
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* failed and not converted.
|
|
*/
|
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if (rec->flags & FTRACE_FL_FREE ||
|
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rec->flags & FTRACE_FL_FAILED ||
|
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!(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--;
|
|
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;
|
|
|
|
iter->flags |= FTRACE_ITER_HASH;
|
|
|
|
return t_hash_next(m, p, pos);
|
|
}
|
|
|
|
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 {
|
|
iter->idx = -1;
|
|
}
|
|
} 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;
|
|
|
|
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;
|
|
(*pos)++;
|
|
return iter;
|
|
}
|
|
|
|
if (iter->flags & FTRACE_ITER_HASH)
|
|
return t_hash_start(m, pos);
|
|
|
|
if (*pos > 0) {
|
|
if (iter->idx < 0)
|
|
return p;
|
|
(*pos)--;
|
|
iter->idx--;
|
|
}
|
|
|
|
p = t_next(m, p, pos);
|
|
|
|
if (!p)
|
|
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_APPEND))
|
|
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 (!(iter->flags & ~FTRACE_ITER_CONT)) {
|
|
/* skip white space */
|
|
while (cnt && isspace(ch)) {
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
|
|
if (isspace(ch)) {
|
|
file->f_pos += 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;
|
|
|
|
|
|
file->f_pos += 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);
|
|
}
|
|
|
|
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, void *v, loff_t *pos)
|
|
{
|
|
unsigned long *array = m->private;
|
|
int index = *pos;
|
|
|
|
(*pos)++;
|
|
|
|
if (index >= ftrace_graph_count)
|
|
return NULL;
|
|
|
|
return &array[index];
|
|
}
|
|
|
|
static void *g_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
void *p = NULL;
|
|
|
|
mutex_lock(&graph_lock);
|
|
|
|
/* Nothing, tell g_show to print all functions are enabled */
|
|
if (!ftrace_graph_count && !*pos)
|
|
return (void *)1;
|
|
|
|
p = g_next(m, p, pos);
|
|
|
|
return p;
|
|
}
|
|
|
|
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_APPEND)) {
|
|
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_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,
|
|
};
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
|
|
{
|
|
struct dentry *entry;
|
|
|
|
entry = debugfs_create_file("available_filter_functions", 0444,
|
|
d_tracer, NULL, &ftrace_avail_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'available_filter_functions' entry\n");
|
|
|
|
entry = debugfs_create_file("failures", 0444,
|
|
d_tracer, NULL, &ftrace_failures_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'failures' entry\n");
|
|
|
|
entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer,
|
|
NULL, &ftrace_filter_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'set_ftrace_filter' entry\n");
|
|
|
|
entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer,
|
|
NULL, &ftrace_notrace_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'set_ftrace_notrace' entry\n");
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
entry = debugfs_create_file("set_graph_function", 0444, d_tracer,
|
|
NULL,
|
|
&ftrace_graph_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'set_graph_function' entry\n");
|
|
#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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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);
|
|
|
|
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;
|
|
struct dentry *entry;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
ftrace_init_dyn_debugfs(d_tracer);
|
|
|
|
entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer,
|
|
NULL, &ftrace_pid_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'set_ftrace_pid' entry\n");
|
|
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 atomic_t 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) {
|
|
t->curr_ret_stack = -1;
|
|
/* Make sure IRQs see the -1 first: */
|
|
barrier();
|
|
t->ret_stack = ret_stack_list[start++];
|
|
atomic_set(&t->tracing_graph_pause, 0);
|
|
atomic_set(&t->trace_overrun, 0);
|
|
}
|
|
} 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 (atomic_read(&ftrace_graph_active)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
|
|
register_pm_notifier(&ftrace_suspend_notifier);
|
|
|
|
atomic_inc(&ftrace_graph_active);
|
|
ret = start_graph_tracing();
|
|
if (ret) {
|
|
atomic_dec(&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(atomic_read(&ftrace_graph_active)))
|
|
goto out;
|
|
|
|
atomic_dec(&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)
|
|
{
|
|
if (atomic_read(&ftrace_graph_active)) {
|
|
t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
|
|
* sizeof(struct ftrace_ret_stack),
|
|
GFP_KERNEL);
|
|
if (!t->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;
|
|
} else
|
|
t->ret_stack = NULL;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
void ftrace_graph_stop(void)
|
|
{
|
|
ftrace_stop();
|
|
}
|
|
#endif
|
|
|