![Ingo Molnar](/assets/img/avatar_default.png)
factor out code and clean it up. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1241 lines
26 KiB
C
1241 lines
26 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/debugfs.h>
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#include <linux/kthread.h>
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#include <linux/hardirq.h>
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#include <linux/ftrace.h>
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#include <linux/uaccess.h>
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#include <linux/sysctl.h>
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#include <linux/hash.h>
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#include <linux/ctype.h>
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#include <linux/list.h>
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#include "trace.h"
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int ftrace_enabled;
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static int last_ftrace_enabled;
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static DEFINE_SPINLOCK(ftrace_lock);
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static DEFINE_MUTEX(ftrace_sysctl_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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/* mcount is defined per arch in assembly */
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EXPORT_SYMBOL(mcount);
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notrace 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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/**
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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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}
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static int notrace __register_ftrace_function(struct ftrace_ops *ops)
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{
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/* Should never be called by interrupts */
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spin_lock(&ftrace_lock);
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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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/*
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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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if (ops->next == &ftrace_list_end)
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ftrace_trace_function = ops->func;
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else
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ftrace_trace_function = ftrace_list_func;
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}
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spin_unlock(&ftrace_lock);
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return 0;
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}
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static int notrace __unregister_ftrace_function(struct ftrace_ops *ops)
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{
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struct ftrace_ops **p;
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int ret = 0;
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spin_lock(&ftrace_lock);
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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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goto out;
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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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ret = -1;
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goto out;
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}
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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 == &ftrace_list_end ||
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ftrace_list->next == &ftrace_list_end)
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ftrace_trace_function = ftrace_list->func;
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}
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out:
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spin_unlock(&ftrace_lock);
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return ret;
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}
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#ifdef CONFIG_DYNAMIC_FTRACE
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static struct task_struct *ftraced_task;
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static DECLARE_WAIT_QUEUE_HEAD(ftraced_waiters);
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static unsigned long ftraced_iteration_counter;
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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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};
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static int ftrace_filtered;
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static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
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static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
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static DEFINE_SPINLOCK(ftrace_shutdown_lock);
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static DEFINE_MUTEX(ftraced_lock);
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static DEFINE_MUTEX(ftrace_filter_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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} __attribute__((packed));
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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 int ftraced_trigger;
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static int ftraced_suspend;
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static int ftrace_record_suspend;
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static inline int
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notrace ftrace_ip_in_hash(unsigned long ip, unsigned long key)
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{
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struct dyn_ftrace *p;
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struct hlist_node *t;
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int found = 0;
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hlist_for_each_entry(p, t, &ftrace_hash[key], node) {
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if (p->ip == ip) {
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found = 1;
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break;
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}
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}
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return found;
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}
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static inline void notrace
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ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
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{
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hlist_add_head(&node->node, &ftrace_hash[key]);
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}
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static notrace struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
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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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return NULL;
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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 void notrace
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ftrace_record_ip(unsigned long ip)
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{
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struct dyn_ftrace *node;
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unsigned long flags;
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unsigned long key;
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int resched;
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int atomic;
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if (!ftrace_enabled)
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return;
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resched = need_resched();
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preempt_disable_notrace();
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/* We simply need to protect against recursion */
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__get_cpu_var(ftrace_shutdown_disable_cpu)++;
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if (__get_cpu_var(ftrace_shutdown_disable_cpu) != 1)
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goto out;
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if (unlikely(ftrace_record_suspend))
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goto out;
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key = hash_long(ip, FTRACE_HASHBITS);
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WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
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if (ftrace_ip_in_hash(ip, key))
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goto out;
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atomic = irqs_disabled();
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spin_lock_irqsave(&ftrace_shutdown_lock, flags);
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/* This ip may have hit the hash before the lock */
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if (ftrace_ip_in_hash(ip, key))
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goto out_unlock;
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/*
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* There's a slight race that the ftraced will update the
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* hash and reset here. If it is already converted, skip it.
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*/
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if (ftrace_ip_converted(ip))
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goto out_unlock;
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node = ftrace_alloc_dyn_node(ip);
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if (!node)
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goto out_unlock;
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node->ip = ip;
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ftrace_add_hash(node, key);
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ftraced_trigger = 1;
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out_unlock:
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spin_unlock_irqrestore(&ftrace_shutdown_lock, flags);
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out:
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__get_cpu_var(ftrace_shutdown_disable_cpu)--;
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/* prevent recursion with scheduler */
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if (resched)
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preempt_enable_no_resched_notrace();
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else
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preempt_enable_notrace();
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}
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#define FTRACE_ADDR ((long)(&ftrace_caller))
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#define MCOUNT_ADDR ((long)(&mcount))
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static void notrace
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__ftrace_replace_code(struct dyn_ftrace *rec,
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unsigned char *old, unsigned char *new, int enable)
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{
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unsigned long ip;
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int failed;
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ip = rec->ip;
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if (ftrace_filtered && enable) {
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unsigned long fl;
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/*
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* If filtering is on:
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*
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* If this record is set to be filtered and
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* is enabled then do nothing.
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*
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* If this record is set to be filtered and
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* it is not enabled, enable it.
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*
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* If this record is not set to be filtered
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* and it is not enabled do nothing.
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*
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* If this record is not set to be filtered and
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* it is enabled, disable it.
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*/
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fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
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if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
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(fl == 0))
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return;
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/*
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* If it is enabled disable it,
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* otherwise enable it!
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*/
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if (fl == FTRACE_FL_ENABLED) {
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/* swap new and old */
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new = old;
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old = ftrace_call_replace(ip, FTRACE_ADDR);
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rec->flags &= ~FTRACE_FL_ENABLED;
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} else {
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new = ftrace_call_replace(ip, FTRACE_ADDR);
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rec->flags |= FTRACE_FL_ENABLED;
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}
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} else {
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if (enable)
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new = ftrace_call_replace(ip, FTRACE_ADDR);
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else
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old = ftrace_call_replace(ip, FTRACE_ADDR);
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if (enable) {
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if (rec->flags & FTRACE_FL_ENABLED)
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return;
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rec->flags |= FTRACE_FL_ENABLED;
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} else {
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if (!(rec->flags & FTRACE_FL_ENABLED))
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return;
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rec->flags &= ~FTRACE_FL_ENABLED;
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}
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}
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failed = ftrace_modify_code(ip, old, new);
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if (failed)
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rec->flags |= FTRACE_FL_FAILED;
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}
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static void notrace ftrace_replace_code(int enable)
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{
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unsigned char *new = NULL, *old = NULL;
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struct dyn_ftrace *rec;
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struct ftrace_page *pg;
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int i;
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if (enable)
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old = ftrace_nop_replace();
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else
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new = ftrace_nop_replace();
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for (pg = ftrace_pages_start; pg; pg = pg->next) {
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for (i = 0; i < pg->index; i++) {
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rec = &pg->records[i];
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/* don't modify code that has already faulted */
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if (rec->flags & FTRACE_FL_FAILED)
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continue;
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__ftrace_replace_code(rec, old, new, enable);
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}
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}
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}
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static notrace void ftrace_shutdown_replenish(void)
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{
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if (ftrace_pages->next)
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return;
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/* allocate another page */
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ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
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}
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static notrace void
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ftrace_code_disable(struct dyn_ftrace *rec)
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{
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unsigned long ip;
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unsigned char *nop, *call;
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int failed;
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ip = rec->ip;
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nop = ftrace_nop_replace();
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call = ftrace_call_replace(ip, MCOUNT_ADDR);
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failed = ftrace_modify_code(ip, call, nop);
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if (failed)
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rec->flags |= FTRACE_FL_FAILED;
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}
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static int notrace __ftrace_modify_code(void *data)
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{
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unsigned long addr;
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int *command = data;
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if (*command & FTRACE_ENABLE_CALLS)
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ftrace_replace_code(1);
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else if (*command & FTRACE_DISABLE_CALLS)
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ftrace_replace_code(0);
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if (*command & FTRACE_UPDATE_TRACE_FUNC)
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ftrace_update_ftrace_func(ftrace_trace_function);
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if (*command & FTRACE_ENABLE_MCOUNT) {
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addr = (unsigned long)ftrace_record_ip;
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ftrace_mcount_set(&addr);
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} else if (*command & FTRACE_DISABLE_MCOUNT) {
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addr = (unsigned long)ftrace_stub;
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ftrace_mcount_set(&addr);
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}
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return 0;
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}
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static void notrace ftrace_run_update_code(int command)
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{
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stop_machine_run(__ftrace_modify_code, &command, NR_CPUS);
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}
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static ftrace_func_t saved_ftrace_func;
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static void notrace ftrace_startup(void)
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{
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int command = 0;
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mutex_lock(&ftraced_lock);
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ftraced_suspend++;
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if (ftraced_suspend == 1)
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command |= FTRACE_ENABLE_CALLS;
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if (saved_ftrace_func != ftrace_trace_function) {
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saved_ftrace_func = ftrace_trace_function;
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command |= FTRACE_UPDATE_TRACE_FUNC;
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}
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if (!command || !ftrace_enabled)
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goto out;
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ftrace_run_update_code(command);
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out:
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mutex_unlock(&ftraced_lock);
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}
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static void notrace ftrace_shutdown(void)
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{
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int command = 0;
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mutex_lock(&ftraced_lock);
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ftraced_suspend--;
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if (!ftraced_suspend)
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command |= FTRACE_DISABLE_CALLS;
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if (saved_ftrace_func != ftrace_trace_function) {
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saved_ftrace_func = ftrace_trace_function;
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command |= FTRACE_UPDATE_TRACE_FUNC;
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}
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if (!command || !ftrace_enabled)
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goto out;
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ftrace_run_update_code(command);
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out:
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mutex_unlock(&ftraced_lock);
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}
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static void notrace ftrace_startup_sysctl(void)
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{
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int command = FTRACE_ENABLE_MCOUNT;
|
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|
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mutex_lock(&ftraced_lock);
|
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/* Force update next time */
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saved_ftrace_func = NULL;
|
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/* ftraced_suspend is true if we want ftrace running */
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if (ftraced_suspend)
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command |= FTRACE_ENABLE_CALLS;
|
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|
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ftrace_run_update_code(command);
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mutex_unlock(&ftraced_lock);
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}
|
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|
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static void notrace ftrace_shutdown_sysctl(void)
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{
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int command = FTRACE_DISABLE_MCOUNT;
|
|
|
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mutex_lock(&ftraced_lock);
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/* ftraced_suspend is true if ftrace is running */
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if (ftraced_suspend)
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command |= FTRACE_DISABLE_CALLS;
|
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|
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ftrace_run_update_code(command);
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mutex_unlock(&ftraced_lock);
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}
|
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|
|
static cycle_t ftrace_update_time;
|
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static unsigned long ftrace_update_cnt;
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unsigned long ftrace_update_tot_cnt;
|
|
|
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static int notrace __ftrace_update_code(void *ignore)
|
|
{
|
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struct dyn_ftrace *p;
|
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struct hlist_head head;
|
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struct hlist_node *t;
|
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int save_ftrace_enabled;
|
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cycle_t start, stop;
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int i;
|
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|
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/* Don't be recording funcs now */
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save_ftrace_enabled = ftrace_enabled;
|
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ftrace_enabled = 0;
|
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|
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start = now(raw_smp_processor_id());
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ftrace_update_cnt = 0;
|
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|
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/* No locks needed, the machine is stopped! */
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for (i = 0; i < FTRACE_HASHSIZE; i++) {
|
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if (hlist_empty(&ftrace_hash[i]))
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continue;
|
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head = ftrace_hash[i];
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|
INIT_HLIST_HEAD(&ftrace_hash[i]);
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|
|
/* all CPUS are stopped, we are safe to modify code */
|
|
hlist_for_each_entry(p, t, &head, node) {
|
|
ftrace_code_disable(p);
|
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ftrace_update_cnt++;
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|
}
|
|
|
|
}
|
|
|
|
stop = now(raw_smp_processor_id());
|
|
ftrace_update_time = stop - start;
|
|
ftrace_update_tot_cnt += ftrace_update_cnt;
|
|
|
|
ftrace_enabled = save_ftrace_enabled;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void notrace ftrace_update_code(void)
|
|
{
|
|
stop_machine_run(__ftrace_update_code, NULL, NR_CPUS);
|
|
}
|
|
|
|
static int notrace ftraced(void *ignore)
|
|
{
|
|
unsigned long usecs;
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
|
|
while (!kthread_should_stop()) {
|
|
|
|
/* check once a second */
|
|
schedule_timeout(HZ);
|
|
|
|
mutex_lock(&ftrace_sysctl_lock);
|
|
mutex_lock(&ftraced_lock);
|
|
if (ftrace_enabled && ftraced_trigger && !ftraced_suspend) {
|
|
ftrace_record_suspend++;
|
|
ftrace_update_code();
|
|
usecs = nsecs_to_usecs(ftrace_update_time);
|
|
if (ftrace_update_tot_cnt > 100000) {
|
|
ftrace_update_tot_cnt = 0;
|
|
pr_info("hm, dftrace overflow: %lu change%s"
|
|
" (%lu total) in %lu usec%s\n",
|
|
ftrace_update_cnt,
|
|
ftrace_update_cnt != 1 ? "s" : "",
|
|
ftrace_update_tot_cnt,
|
|
usecs, usecs != 1 ? "s" : "");
|
|
WARN_ON_ONCE(1);
|
|
}
|
|
ftraced_trigger = 0;
|
|
ftrace_record_suspend--;
|
|
}
|
|
ftraced_iteration_counter++;
|
|
mutex_unlock(&ftraced_lock);
|
|
mutex_unlock(&ftrace_sysctl_lock);
|
|
|
|
wake_up_interruptible(&ftraced_waiters);
|
|
|
|
ftrace_shutdown_replenish();
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
}
|
|
__set_current_state(TASK_RUNNING);
|
|
return 0;
|
|
}
|
|
|
|
static int __init ftrace_dyn_table_alloc(void)
|
|
{
|
|
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 = NR_TO_INIT / ENTRIES_PER_PAGE;
|
|
|
|
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),
|
|
};
|
|
|
|
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
|
|
|
|
struct ftrace_iterator {
|
|
loff_t pos;
|
|
struct ftrace_page *pg;
|
|
unsigned idx;
|
|
unsigned flags;
|
|
unsigned char buffer[FTRACE_BUFF_MAX+1];
|
|
unsigned buffer_idx;
|
|
unsigned filtered;
|
|
};
|
|
|
|
static void notrace *
|
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct ftrace_iterator *iter = m->private;
|
|
struct dyn_ftrace *rec = NULL;
|
|
|
|
(*pos)++;
|
|
|
|
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_FAILED) ||
|
|
((iter->flags & FTRACE_ITER_FILTER) &&
|
|
!(rec->flags & FTRACE_FL_FILTER))) {
|
|
rec = NULL;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
iter->pos = *pos;
|
|
|
|
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 = -1;
|
|
|
|
if (*pos != iter->pos) {
|
|
for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
|
|
;
|
|
} else {
|
|
l = *pos;
|
|
p = t_next(m, p, &l);
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
}
|
|
|
|
static int t_show(struct seq_file *m, void *v)
|
|
{
|
|
struct dyn_ftrace *rec = v;
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
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 notrace
|
|
ftrace_avail_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
int ret;
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
iter->pg = ftrace_pages_start;
|
|
iter->pos = -1;
|
|
|
|
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 void notrace ftrace_filter_reset(void)
|
|
{
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
unsigned i;
|
|
|
|
/* keep kstop machine from running */
|
|
preempt_disable();
|
|
ftrace_filtered = 0;
|
|
pg = ftrace_pages_start;
|
|
while (pg) {
|
|
for (i = 0; i < pg->index; i++) {
|
|
rec = &pg->records[i];
|
|
if (rec->flags & FTRACE_FL_FAILED)
|
|
continue;
|
|
rec->flags &= ~FTRACE_FL_FILTER;
|
|
}
|
|
pg = pg->next;
|
|
}
|
|
preempt_enable();
|
|
}
|
|
|
|
static int notrace
|
|
ftrace_filter_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
int ret = 0;
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&ftrace_filter_lock);
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
!(file->f_flags & O_APPEND))
|
|
ftrace_filter_reset();
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter->pg = ftrace_pages_start;
|
|
iter->pos = -1;
|
|
iter->flags = FTRACE_ITER_FILTER;
|
|
|
|
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_filter_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t notrace
|
|
ftrace_filter_read(struct file *file, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
if (file->f_mode & FMODE_READ)
|
|
return seq_read(file, ubuf, cnt, ppos);
|
|
else
|
|
return -EPERM;
|
|
}
|
|
|
|
static loff_t notrace
|
|
ftrace_filter_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 void notrace
|
|
ftrace_match(unsigned char *buff, int len)
|
|
{
|
|
char str[KSYM_SYMBOL_LEN];
|
|
char *search = NULL;
|
|
struct ftrace_page *pg;
|
|
struct dyn_ftrace *rec;
|
|
int type = MATCH_FULL;
|
|
unsigned i, match = 0, search_len = 0;
|
|
|
|
for (i = 0; i < len; i++) {
|
|
if (buff[i] == '*') {
|
|
if (!i) {
|
|
search = buff + i + 1;
|
|
type = MATCH_END_ONLY;
|
|
search_len = len - (i + 1);
|
|
} else {
|
|
if (type == MATCH_END_ONLY) {
|
|
type = MATCH_MIDDLE_ONLY;
|
|
} else {
|
|
match = i;
|
|
type = MATCH_FRONT_ONLY;
|
|
}
|
|
buff[i] = 0;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* keep kstop machine from running */
|
|
preempt_disable();
|
|
ftrace_filtered = 1;
|
|
pg = ftrace_pages_start;
|
|
while (pg) {
|
|
for (i = 0; i < pg->index; i++) {
|
|
int matched = 0;
|
|
char *ptr;
|
|
|
|
rec = &pg->records[i];
|
|
if (rec->flags & FTRACE_FL_FAILED)
|
|
continue;
|
|
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
|
|
switch (type) {
|
|
case MATCH_FULL:
|
|
if (strcmp(str, buff) == 0)
|
|
matched = 1;
|
|
break;
|
|
case MATCH_FRONT_ONLY:
|
|
if (memcmp(str, buff, match) == 0)
|
|
matched = 1;
|
|
break;
|
|
case MATCH_MIDDLE_ONLY:
|
|
if (strstr(str, search))
|
|
matched = 1;
|
|
break;
|
|
case MATCH_END_ONLY:
|
|
ptr = strstr(str, search);
|
|
if (ptr && (ptr[search_len] == 0))
|
|
matched = 1;
|
|
break;
|
|
}
|
|
if (matched)
|
|
rec->flags |= FTRACE_FL_FILTER;
|
|
}
|
|
pg = pg->next;
|
|
}
|
|
preempt_enable();
|
|
}
|
|
|
|
static ssize_t notrace
|
|
ftrace_filter_write(struct file *file, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct ftrace_iterator *iter;
|
|
char ch;
|
|
size_t read = 0;
|
|
ssize_t ret;
|
|
|
|
if (!cnt || cnt < 0)
|
|
return 0;
|
|
|
|
mutex_lock(&ftrace_filter_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;
|
|
ftrace_match(iter->buffer, iter->buffer_idx);
|
|
iter->buffer_idx = 0;
|
|
} else
|
|
iter->flags |= FTRACE_ITER_CONT;
|
|
|
|
|
|
file->f_pos += read;
|
|
|
|
ret = read;
|
|
out:
|
|
mutex_unlock(&ftrace_filter_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int notrace
|
|
ftrace_filter_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *m = (struct seq_file *)file->private_data;
|
|
struct ftrace_iterator *iter;
|
|
|
|
mutex_lock(&ftrace_filter_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(iter->buffer, iter->buffer_idx);
|
|
}
|
|
|
|
mutex_lock(&ftrace_sysctl_lock);
|
|
mutex_lock(&ftraced_lock);
|
|
if (iter->filtered && ftraced_suspend && ftrace_enabled)
|
|
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
|
|
mutex_unlock(&ftraced_lock);
|
|
mutex_unlock(&ftrace_sysctl_lock);
|
|
|
|
kfree(iter);
|
|
mutex_unlock(&ftrace_filter_lock);
|
|
return 0;
|
|
}
|
|
|
|
static struct file_operations ftrace_avail_fops = {
|
|
.open = ftrace_avail_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = ftrace_avail_release,
|
|
};
|
|
|
|
static struct file_operations ftrace_filter_fops = {
|
|
.open = ftrace_filter_open,
|
|
.read = ftrace_filter_read,
|
|
.write = ftrace_filter_write,
|
|
.llseek = ftrace_filter_lseek,
|
|
.release = ftrace_filter_release,
|
|
};
|
|
|
|
/**
|
|
* ftrace_force_update - force an update to all recording ftrace functions
|
|
*
|
|
* The ftrace dynamic update daemon only wakes up once a second.
|
|
* There may be cases where an update needs to be done immediately
|
|
* for tests or internal kernel tracing to begin. This function
|
|
* wakes the daemon to do an update and will not return until the
|
|
* update is complete.
|
|
*/
|
|
int ftrace_force_update(void)
|
|
{
|
|
unsigned long last_counter;
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
int ret = 0;
|
|
|
|
if (!ftraced_task)
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&ftraced_lock);
|
|
last_counter = ftraced_iteration_counter;
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
add_wait_queue(&ftraced_waiters, &wait);
|
|
|
|
do {
|
|
mutex_unlock(&ftraced_lock);
|
|
wake_up_process(ftraced_task);
|
|
schedule();
|
|
mutex_lock(&ftraced_lock);
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
} while (last_counter == ftraced_iteration_counter);
|
|
|
|
mutex_unlock(&ftraced_lock);
|
|
remove_wait_queue(&ftraced_waiters, &wait);
|
|
set_current_state(TASK_RUNNING);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static __init int ftrace_init_debugfs(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
struct dentry *entry;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
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("set_ftrace_filter", 0644, d_tracer,
|
|
NULL, &ftrace_filter_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'set_ftrace_filter' entry\n");
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(ftrace_init_debugfs);
|
|
|
|
static int __init notrace ftrace_dynamic_init(void)
|
|
{
|
|
struct task_struct *p;
|
|
unsigned long addr;
|
|
int ret;
|
|
|
|
addr = (unsigned long)ftrace_record_ip;
|
|
stop_machine_run(ftrace_dyn_arch_init, &addr, NR_CPUS);
|
|
|
|
/* ftrace_dyn_arch_init places the return code in addr */
|
|
if (addr)
|
|
return addr;
|
|
|
|
ret = ftrace_dyn_table_alloc();
|
|
if (ret)
|
|
return ret;
|
|
|
|
p = kthread_run(ftraced, NULL, "ftraced");
|
|
if (IS_ERR(p))
|
|
return -1;
|
|
|
|
last_ftrace_enabled = ftrace_enabled = 1;
|
|
ftraced_task = p;
|
|
|
|
return 0;
|
|
}
|
|
|
|
core_initcall(ftrace_dynamic_init);
|
|
#else
|
|
# define ftrace_startup() do { } while (0)
|
|
# define ftrace_shutdown() do { } while (0)
|
|
# define ftrace_startup_sysctl() do { } while (0)
|
|
# define ftrace_shutdown_sysctl() do { } while (0)
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
/**
|
|
* 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;
|
|
|
|
mutex_lock(&ftrace_sysctl_lock);
|
|
ret = __register_ftrace_function(ops);
|
|
ftrace_startup();
|
|
mutex_unlock(&ftrace_sysctl_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* unregister_ftrace_function - unresgister 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_sysctl_lock);
|
|
ret = __unregister_ftrace_function(ops);
|
|
ftrace_shutdown();
|
|
mutex_unlock(&ftrace_sysctl_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
notrace int
|
|
ftrace_enable_sysctl(struct ctl_table *table, int write,
|
|
struct file *file, void __user *buffer, size_t *lenp,
|
|
loff_t *ppos)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&ftrace_sysctl_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_sysctl_lock);
|
|
return ret;
|
|
}
|