android_kernel_motorola_sm6225/arch/x86/kernel/stacktrace.c
Vegard Nossum 1650743cdc x86: don't save unreliable stack trace entries
Currently, there is no way for print_stack_trace() to determine whether
a given stack trace entry was deemed reliable or not, simply because
save_stack_trace() does not record this information. (Perhaps needless
to say, this makes the saved stack traces A LOT harder to read, and
probably with no other benefits, since debugging features that use
save_stack_trace() most likely also require frame pointers, etc.)

This patch reverts to the old behaviour of only recording the reliable trace
entries for saved stack traces.

Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-26 12:55:58 +01:00

83 lines
2 KiB
C

/*
* Stack trace management functions
*
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/module.h>
#include <asm/stacktrace.h>
static void save_stack_warning(void *data, char *msg)
{
}
static void
save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
{
}
static int save_stack_stack(void *data, char *name)
{
return -1;
}
static void save_stack_address(void *data, unsigned long addr, int reliable)
{
struct stack_trace *trace = data;
if (!reliable)
return;
if (trace->skip > 0) {
trace->skip--;
return;
}
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = addr;
}
static void
save_stack_address_nosched(void *data, unsigned long addr, int reliable)
{
struct stack_trace *trace = (struct stack_trace *)data;
if (!reliable)
return;
if (in_sched_functions(addr))
return;
if (trace->skip > 0) {
trace->skip--;
return;
}
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = addr;
}
static const struct stacktrace_ops save_stack_ops = {
.warning = save_stack_warning,
.warning_symbol = save_stack_warning_symbol,
.stack = save_stack_stack,
.address = save_stack_address,
};
static const struct stacktrace_ops save_stack_ops_nosched = {
.warning = save_stack_warning,
.warning_symbol = save_stack_warning_symbol,
.stack = save_stack_stack,
.address = save_stack_address_nosched,
};
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
void save_stack_trace(struct stack_trace *trace)
{
dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}