Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing/kprobes: Fix probe parsing
  tracing: Fix circular dead lock in stack trace
This commit is contained in:
Linus Torvalds
2010-02-15 19:47:59 -08:00
2 changed files with 25 additions and 1 deletions

View File

@@ -689,7 +689,7 @@ static int create_trace_probe(int argc, char **argv)
return -EINVAL; return -EINVAL;
} }
/* an address specified */ /* an address specified */
ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr); ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
if (ret) { if (ret) {
pr_info("Failed to parse address.\n"); pr_info("Failed to parse address.\n");
return ret; return ret;

View File

@@ -157,6 +157,7 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
unsigned long val, flags; unsigned long val, flags;
char buf[64]; char buf[64];
int ret; int ret;
int cpu;
if (count >= sizeof(buf)) if (count >= sizeof(buf))
return -EINVAL; return -EINVAL;
@@ -171,9 +172,20 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
return ret; return ret;
local_irq_save(flags); local_irq_save(flags);
/*
* In case we trace inside arch_spin_lock() or after (NMI),
* we will cause circular lock, so we also need to increase
* the percpu trace_active here.
*/
cpu = smp_processor_id();
per_cpu(trace_active, cpu)++;
arch_spin_lock(&max_stack_lock); arch_spin_lock(&max_stack_lock);
*ptr = val; *ptr = val;
arch_spin_unlock(&max_stack_lock); arch_spin_unlock(&max_stack_lock);
per_cpu(trace_active, cpu)--;
local_irq_restore(flags); local_irq_restore(flags);
return count; return count;
@@ -206,7 +218,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
static void *t_start(struct seq_file *m, loff_t *pos) static void *t_start(struct seq_file *m, loff_t *pos)
{ {
int cpu;
local_irq_disable(); local_irq_disable();
cpu = smp_processor_id();
per_cpu(trace_active, cpu)++;
arch_spin_lock(&max_stack_lock); arch_spin_lock(&max_stack_lock);
if (*pos == 0) if (*pos == 0)
@@ -217,7 +235,13 @@ static void *t_start(struct seq_file *m, loff_t *pos)
static void t_stop(struct seq_file *m, void *p) static void t_stop(struct seq_file *m, void *p)
{ {
int cpu;
arch_spin_unlock(&max_stack_lock); arch_spin_unlock(&max_stack_lock);
cpu = smp_processor_id();
per_cpu(trace_active, cpu)--;
local_irq_enable(); local_irq_enable();
} }