我遇到一个问题,即任何Leak Sanitizer回溯通过动态加载的库报告Unknown Module
进行该库中的任何函数调用。
Direct leak of 48 byte(s) in 1 object(s) allocated from:
#0 0x4e3e36 in malloc (/usr/sbin/radiusd+0x4e3e36)
#1 0x7fb406e95f69 (<unknown module>)
#2 0x7fb406eafc36 (<unknown module>)
#3 0x7fb406eafd40 (<unknown module>)
#4 0x7fb406ea3364 (<unknown module>)
#5 0x7fb4063de7d4 (<unknown module>)
#6 0x7fb4063c61c4 (<unknown module>)
#7 0x7fb406617863 (<unknown module>)
#8 0x7fb415620681 in dl_load_func /usr/src/debug/freeradius-server-4.0.0/src/main/dl.c:194:34
#9 0x7fb41561edab in dl_symbol_init_walk /usr/src/debug/freeradius-server-4.0.0/src/main/dl.c:301:7
#10 0x7fb41561df1e in dl_module /usr/src/debug/freeradius-server-4.0.0/src/main/dl.c:748:6
#11 0x7fb41561f3db in dl_instance /usr/src/debug/freeradius-server-4.0.0/src/main/dl.c:853:20
#12 0x7fb41564f4ab in module_bootstrap /usr/src/debug/freeradius-server-4.0.0/src/main/module.c:827:6
#13 0x7fb41564ed56 in modules_bootstrap /usr/src/debug/freeradius-server-4.0.0/src/main/module.c:1070:14
#14 0x5352bb in main /usr/src/debug/freeradius-server-4.0.0/src/main/radiusd.c:561:6
#15 0x7fb41282ab34 in __libc_start_main (/lib64/libc.so.6+0x21b34)
#16 0x4204ab in _start (/usr/sbin/radiusd+0x4204ab)
我之前和valgrind有过几乎完全相同的问题,我知道这是因为在退出时卸载了dlclose库,并且符号器运行时符号不可用。
使用valgrind,修复很简单
/*
* Only dlclose() handle if we're *NOT* running under valgrind
* as it unloads the symbols valgrind needs.
*/
if (!RUNNING_ON_VALGRIND) dlclose(module->handle); /* ignore any errors */
RUNNING_ON_VALGRIND
是valgrind库提供的宏,用于检测程序是否为valground。
在设置ASAN_OPTIONS=detect_leaks=1
时,我无法在LSAN文档中看到类似功能的任何内容。
是否有人知道是否可以在LSAN下运行运行时检查?
答案 0 :(得分:1)
首先,不在detect_leaks=0
打印堆栈跟踪(或打印不正确的堆栈跟踪)在所有清洁剂(不仅仅是LSan)中都是known issue。
其次,截至目前,还没有API可以检测到LeakSanitizer在运行时启用,因此最好的办法是手动检查程序是否与Lsan相关联,并且void (*__lsan_is_turned_off)() = dlsym(RTLD_DEFAULT, "__lsan_is_turned_off");
const char *lsan_opts = getenv("LSAN_OPTIONS");
const char *asan_opts = getenv("ASAN_OPTIONS");
int disable_dlclose = __lsan_is_turned_off != 0 && !__lsan_is_turned_off()
&& !(lsan_opts && (strstr(lsan_opts, "detect_leaks=0") || strstr(lsan_opts, "detect_leaks=false"))
&& !(asan_opts && (strstr(asan_opts, "detect_leaks=0") || strstr(asan_opts, "detect_leaks=false"));
未设置为环境:
__lsan_is_turned_off
(-fsanitize=address
中定义了__lsan_is_turned_off
。
如果您通过#ifdef __SANITIZE_ADDRESS__
启用LSan,则可以将let children = document.querySelectorAll('.child')
function addClass(className, idx) {
if (typeof idx === 'undefined') {
idx = 0
}
if (children.length>idx) {
children[idx].classList.add(className)
setTimeout(function() {
addClass(className, idx+1)
}, 1000)
}
}
addClass('changed')
替换为#container {
padding: 4px;
font-family: sans-serif;
}
.child {
background: #02042e;
color: white;
}
.changed {
background: #1010ff;
}
。
答案 1 :(得分:1)
LSAN接口标头允许用户定义回调__lsan_is_turned_off
以允许程序禁用泄漏检查程序。只有在启用LSAN时才会执行此回调。
#include <sanitizer/lsan_interface.h>
static bool running_under_lsan = false;
int __attribute__((used)) __lsan_is_turned_off(void)
{
running_under_lsan = true;
return 0;
}
编辑:实际上比这更复杂。正如@yugr所评论的那样,只有在进程或子进程退出时才会执行__lsan_is_turned_off
。
但是有一个解决方案!
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sanitizer/common_interface_defs.h>
static int from_child[2] = {-1, -1};
static int pid;
int __attribute__((used)) __lsan_is_turned_off(void)
{
uint8_t ret = 1;
/* Parent */
if (pid != 0) return 0;
/* Child */
if (write(from_child[1], &ret, sizeof(ret)) < 0) {
fprintf(stderr, "Writing LSAN status failed: %s", strerror(errno));
}
close(from_child[1]);
return 0;
}
int main(int argc, char **argv)
{
uint8_t ret = 0;
if (pipe(from_child) < 0) {
fprintf(stderr, "Failed opening internal pipe: %s", strerror(errno));
exit(EXIT_FAILURE);
}
pid = fork();
if (pid == -1) {
fprintf(stderr, "Error forking: %s", strerror(errno));
exit(EXIT_FAILURE);
}
/* Child */
if (pid == 0) {
close(from_child[0]); /* Close parent's side */
exit(EXIT_SUCCESS);
}
/* Parent */
close(from_child[1]); /* Close child's side */
while ((read(from_child[0], &ret, sizeof(ret)) < 0) && (errno == EINTR));
close(from_child[0]); /* Close our side (so we don't leak FDs) */
/* Collect child */
waitpid(pid, NULL, 0);
if (ret) {
printf("Running under LSAN\n");
} else {
printf("Not running under LSAN\n");
}
exit(EXIT_SUCCESS);
}
示例:
clang -g3 -fsanitize=address foo.c
ASAN_OPTIONS='detect_leaks=1' ./a.out
Running under LSAN
ASAN_OPTIONS='detect_leaks=0' ./a.out
Not running under LSAN