From a32c7765e2796395aec49f699bd25c407155e9c5 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 26 Jun 2009 16:55:51 +0800 Subject: tracing: Fix stack tracer sysctl handling This made my machine completely frozen: # echo 1 > /proc/sys/kernel/stack_tracer_enabled # echo 2 > /proc/sys/kernel/stack_tracer_enabled The cause is register_ftrace_function() was called twice. Also fix ftrace_enabled sysctl, though seems nothing bad happened as I tested it. Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A448D17.9010305@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_stack.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace/trace_stack.c') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 2d7aebd71dbd..e644af910124 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -326,10 +326,10 @@ stack_trace_sysctl(struct ctl_table *table, int write, ret = proc_dointvec(table, write, file, buffer, lenp, ppos); if (ret || !write || - (last_stack_tracer_enabled == stack_tracer_enabled)) + (last_stack_tracer_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = stack_tracer_enabled; + last_stack_tracer_enabled = !!stack_tracer_enabled; if (stack_tracer_enabled) register_ftrace_function(&trace_ops); -- cgit v1.2.2 From 79173bf556417a737e9d2e096e0788452ec30a61 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 16 Jul 2009 14:17:11 +0800 Subject: tracing/trace_stack: Cleanup for trace_lookup_stack() We can directly use %pF input format instead of sprint_symbol() and %s input format. Signed-off-by: Xiao Guangrong Reviewed-by: Li Zefan Signed-off-by: Frederic Weisbecker --- kernel/trace/trace_stack.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'kernel/trace/trace_stack.c') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index e644af910124..a4dc8d9ad1b1 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -234,15 +234,8 @@ static void t_stop(struct seq_file *m, void *p) static int trace_lookup_stack(struct seq_file *m, long i) { unsigned long addr = stack_dump_trace[i]; -#ifdef CONFIG_KALLSYMS - char str[KSYM_SYMBOL_LEN]; - sprint_symbol(str, addr); - - return seq_printf(m, "%s\n", str); -#else - return seq_printf(m, "%p\n", (void*)addr); -#endif + return seq_printf(m, "%pF\n", (void *)addr); } static void print_disabled(struct seq_file *m) -- cgit v1.2.2 From d8cc1ab793993c886c62abf77c93287df33ffd8b Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 23 Jul 2009 11:28:40 +0800 Subject: trace_stack: Fix seqfile memory leak Every time we cat stack_trace, we leak memory allocated by seq_open(). Signed-off-by: Li Zefan LKML-Reference: <4A67D8E8.3020500@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_stack.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'kernel/trace/trace_stack.c') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index e644af910124..6a2a9d484cd6 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -301,17 +301,14 @@ static const struct seq_operations stack_trace_seq_ops = { static int stack_trace_open(struct inode *inode, struct file *file) { - int ret; - - ret = seq_open(file, &stack_trace_seq_ops); - - return ret; + return seq_open(file, &stack_trace_seq_ops); } static const struct file_operations stack_trace_fops = { .open = stack_trace_open, .read = seq_read, .llseek = seq_lseek, + .release = seq_release, }; int -- cgit v1.2.2 From 2fc5f0cff4cf1c4cd336d0f61f11bca6eeee1d84 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 17 Aug 2009 16:53:37 +0800 Subject: trace_stack: Simplify seqfile code Extract duplicate code in t_start() and t_next(). Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A891A91.4030602@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_stack.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) (limited to 'kernel/trace/trace_stack.c') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 0da1cff08d67..0f6facb050a1 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = { }; static void * -t_next(struct seq_file *m, void *v, loff_t *pos) +__next(struct seq_file *m, loff_t *pos) { - long i; + long n = *pos - 1; - (*pos)++; - - if (v == SEQ_START_TOKEN) - i = 0; - else { - i = *(long *)v; - i++; - } - - if (i >= max_stack_trace.nr_entries || - stack_dump_trace[i] == ULONG_MAX) + if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX) return NULL; - m->private = (void *)i; - + m->private = (void *)n; return &m->private; } -static void *t_start(struct seq_file *m, loff_t *pos) +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) { - void *t = SEQ_START_TOKEN; - loff_t l = 0; + (*pos)++; + return __next(m, pos); +} +static void *t_start(struct seq_file *m, loff_t *pos) +{ local_irq_disable(); __raw_spin_lock(&max_stack_lock); if (*pos == 0) return SEQ_START_TOKEN; - for (; t && l < *pos; t = t_next(m, t, &l)) - ; - - return t; + return __next(m, pos); } static void t_stop(struct seq_file *m, void *p) -- cgit v1.2.2