/usr/src/openvswitch-1.4.0/lib/backtrace.c is in openvswitch-datapath-dkms 1.4.0-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 | /*
* Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "backtrace.h"
#include <errno.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include "compiler.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(backtrace);
#ifdef HAVE_BACKTRACE
#include <execinfo.h>
void
backtrace_capture(struct backtrace *b)
{
void *frames[BACKTRACE_MAX_FRAMES];
int i;
b->n_frames = backtrace(frames, BACKTRACE_MAX_FRAMES);
for (i = 0; i < b->n_frames; i++) {
b->frames[i] = (uintptr_t) frames[i];
}
}
#elif __GNUC__
static uintptr_t
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, "%*x-%"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)
{
uintptr_t low = (uintptr_t) &low;
return low;
}
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;
}
#else /* !HAVE_BACKTRACE && !__GNUC__ */
void
backtrace_capture(struct backtrace *backtrace)
{
backtrace->n_frames = 0;
}
#endif
|