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Diffstat (limited to 'kernel/trace/trace_stack.c')
-rw-r--r--kernel/trace/trace_stack.c85
1 files changed, 27 insertions, 58 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index eec648a0d673..5d16f73898db 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -18,44 +18,32 @@
#include "trace.h"
-static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
- { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };
-unsigned stack_trace_index[STACK_TRACE_ENTRIES];
+#define STACK_TRACE_ENTRIES 500
-/*
- * Reserve one entry for the passed in ip. This will allow
- * us to remove most or all of the stack size overhead
- * added by the stack tracer itself.
- */
-struct stack_trace stack_trace_max = {
- .max_entries = STACK_TRACE_ENTRIES - 1,
- .entries = &stack_dump_trace[0],
-};
+static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES];
+static unsigned stack_trace_index[STACK_TRACE_ENTRIES];
-unsigned long stack_trace_max_size;
-arch_spinlock_t stack_trace_max_lock =
+static unsigned int stack_trace_nr_entries;
+static unsigned long stack_trace_max_size;
+static arch_spinlock_t stack_trace_max_lock =
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
DEFINE_PER_CPU(int, disable_stack_tracer);
static DEFINE_MUTEX(stack_sysctl_mutex);
int stack_tracer_enabled;
-static int last_stack_tracer_enabled;
-void stack_trace_print(void)
+static void print_max_stack(void)
{
long i;
int size;
pr_emerg(" Depth Size Location (%d entries)\n"
" ----- ---- --------\n",
- stack_trace_max.nr_entries);
+ stack_trace_nr_entries);
- for (i = 0; i < stack_trace_max.nr_entries; i++) {
- if (stack_dump_trace[i] == ULONG_MAX)
- break;
- if (i+1 == stack_trace_max.nr_entries ||
- stack_dump_trace[i+1] == ULONG_MAX)
+ for (i = 0; i < stack_trace_nr_entries; i++) {
+ if (i + 1 == stack_trace_nr_entries)
size = stack_trace_index[i];
else
size = stack_trace_index[i] - stack_trace_index[i+1];
@@ -65,16 +53,7 @@ void stack_trace_print(void)
}
}
-/*
- * When arch-specific code overrides this function, the following
- * data should be filled up, assuming stack_trace_max_lock is held to
- * prevent concurrent updates.
- * stack_trace_index[]
- * stack_trace_max
- * stack_trace_max_size
- */
-void __weak
-check_stack(unsigned long ip, unsigned long *stack)
+static void check_stack(unsigned long ip, unsigned long *stack)
{
unsigned long this_size, flags; unsigned long *p, *top, *start;
static int tracer_frame;
@@ -110,13 +89,12 @@ check_stack(unsigned long ip, unsigned long *stack)
stack_trace_max_size = this_size;
- stack_trace_max.nr_entries = 0;
- stack_trace_max.skip = 0;
-
- save_stack_trace(&stack_trace_max);
+ stack_trace_nr_entries = stack_trace_save(stack_dump_trace,
+ ARRAY_SIZE(stack_dump_trace) - 1,
+ 0);
/* Skip over the overhead of the stack tracer itself */
- for (i = 0; i < stack_trace_max.nr_entries; i++) {
+ for (i = 0; i < stack_trace_nr_entries; i++) {
if (stack_dump_trace[i] == ip)
break;
}
@@ -125,7 +103,7 @@ check_stack(unsigned long ip, unsigned long *stack)
* Some archs may not have the passed in ip in the dump.
* If that happens, we need to show everything.
*/
- if (i == stack_trace_max.nr_entries)
+ if (i == stack_trace_nr_entries)
i = 0;
/*
@@ -143,15 +121,13 @@ check_stack(unsigned long ip, unsigned long *stack)
* loop will only happen once. This code only takes place
* on a new max, so it is far from a fast path.
*/
- while (i < stack_trace_max.nr_entries) {
+ while (i < stack_trace_nr_entries) {
int found = 0;
stack_trace_index[x] = this_size;
p = start;
- for (; p < top && i < stack_trace_max.nr_entries; p++) {
- if (stack_dump_trace[i] == ULONG_MAX)
- break;
+ for (; p < top && i < stack_trace_nr_entries; p++) {
/*
* The READ_ONCE_NOCHECK is used to let KASAN know that
* this is not a stack-out-of-bounds error.
@@ -182,12 +158,10 @@ check_stack(unsigned long ip, unsigned long *stack)
i++;
}
- stack_trace_max.nr_entries = x;
- for (; x < i; x++)
- stack_dump_trace[x] = ULONG_MAX;
+ stack_trace_nr_entries = x;
if (task_stack_end_corrupted(current)) {
- stack_trace_print();
+ print_max_stack();
BUG();
}
@@ -286,7 +260,7 @@ __next(struct seq_file *m, loff_t *pos)
{
long n = *pos - 1;
- if (n >= stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX)
+ if (n >= stack_trace_nr_entries)
return NULL;
m->private = (void *)n;
@@ -350,7 +324,7 @@ static int t_show(struct seq_file *m, void *v)
seq_printf(m, " Depth Size Location"
" (%d entries)\n"
" ----- ---- --------\n",
- stack_trace_max.nr_entries);
+ stack_trace_nr_entries);
if (!stack_tracer_enabled && !stack_trace_max_size)
print_disabled(m);
@@ -360,12 +334,10 @@ static int t_show(struct seq_file *m, void *v)
i = *(long *)v;
- if (i >= stack_trace_max.nr_entries ||
- stack_dump_trace[i] == ULONG_MAX)
+ if (i >= stack_trace_nr_entries)
return 0;
- if (i+1 == stack_trace_max.nr_entries ||
- stack_dump_trace[i+1] == ULONG_MAX)
+ if (i + 1 == stack_trace_nr_entries)
size = stack_trace_index[i];
else
size = stack_trace_index[i] - stack_trace_index[i+1];
@@ -422,23 +394,21 @@ stack_trace_sysctl(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
+ int was_enabled;
int ret;
mutex_lock(&stack_sysctl_mutex);
+ was_enabled = !!stack_tracer_enabled;
ret = proc_dointvec(table, write, buffer, lenp, ppos);
- if (ret || !write ||
- (last_stack_tracer_enabled == !!stack_tracer_enabled))
+ if (ret || !write || (was_enabled == !!stack_tracer_enabled))
goto out;
- last_stack_tracer_enabled = !!stack_tracer_enabled;
-
if (stack_tracer_enabled)
register_ftrace_function(&trace_ops);
else
unregister_ftrace_function(&trace_ops);
-
out:
mutex_unlock(&stack_sysctl_mutex);
return ret;
@@ -454,7 +424,6 @@ static __init int enable_stacktrace(char *str)
strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE);
stack_tracer_enabled = 1;
- last_stack_tracer_enabled = 1;
return 1;
}
__setup("stacktrace", enable_stacktrace);
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-07 18:46:00 +0000