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/*
* Copyright (c) 2008, 2009 Nicira Networks.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include "backtrace.h"
#include <errno.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include "compiler.h"
#define THIS_MODULE VLM_backtrace
#include "vlog.h"
static uintptr_t UNUSED
get_max_stack(void)
{
static const char file_name[] = "/proc/self/maps";
char line[1024];
int line_number;
FILE *f;
f = fopen(file_name, "r");
if (f == NULL) {
VLOG_WARN("opening %s failed: %s", file_name, strerror(errno));
return -1;
}
for (line_number = 1; fgets(line, sizeof line, f); line_number++) {
if (strstr(line, "[stack]")) {
uintptr_t end;
if (sscanf(line, "%*"SCNxPTR"-%"SCNxPTR, &end) != 1) {
VLOG_WARN("%s:%d: parse error", file_name, line_number);
continue;
}
fclose(f);
return end;
}
}
fclose(f);
VLOG_WARN("%s: no stack found", file_name);
return -1;
}
static uintptr_t
stack_high(void)
{
static uintptr_t high;
if (!high) {
high = get_max_stack();
}
return high;
}
static uintptr_t
stack_low(void)
{
#ifdef __i386__
uintptr_t low;
asm("movl %%esp,%0" : "=g" (low));
return low;
#else
/* This causes a warning in GCC that cannot be disabled, so use it only on
* non-x86. */
int dummy;
return (uintptr_t) &dummy;
#endif
}
static bool
in_stack(void *p)
{
uintptr_t address = (uintptr_t) p;
return address >= stack_low() && address < stack_high();
}
void
backtrace_capture(struct backtrace *backtrace)
{
void **frame;
size_t n;
n = 0;
for (frame = __builtin_frame_address(1);
frame != NULL && in_stack(frame) && frame[0] != NULL
&& n < BACKTRACE_MAX_FRAMES;
frame = frame[0])
{
backtrace->frames[n++] = (uintptr_t) frame[1];
}
backtrace->n_frames = n;
}
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