crash log - improve code dump with more info and called symbols.

This commit is contained in:
antirez 2016-09-09 10:59:29 +02:00
parent 24811fcb1b
commit 6211e77ab6

View File

@ -975,6 +975,32 @@ int memtest_test_linux_anonymous_maps(void) {
}
#endif
/* Scans the (assumed) x86 code starting at addr, for a max of `len`
* bytes, searching for E8 (callq) opcodes, and dumping the symbols
* and the call offset if they appear to be valid. */
void dumpX86Calls(void *addr, size_t len) {
size_t j;
unsigned char *p = addr;
Dl_info info;
/* Hash table to best-effort avoid printing the same symbol
* multiple times. */
unsigned long ht[256] = {0};
if (len < 5) return;
for (j = 0; j < len-4; j++) {
if (p[j] != 0xE8) continue; /* Not an E8 CALL opcode. */
unsigned long target = (unsigned long)addr+j+5;
target += *((int32_t*)(p+j+1));
if (dladdr((void*)target, &info) != 0 && info.dli_sname != NULL) {
if (ht[target&0xff] != target) {
printf("Function at 0x%lx is %s\n",target,info.dli_sname);
ht[target&0xff] = target;
}
j += 4; /* Skip the 32 bit immediate. */
}
}
}
void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
ucontext_t *uc = (ucontext_t*) secret;
void *eip = getMcontextEip(uc);
@ -1025,39 +1051,52 @@ void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
bioKillThreads();
if (memtest_test_linux_anonymous_maps()) {
serverLogRaw(LL_WARNING|LL_RAW,
"!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
"!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!\n");
} else {
serverLogRaw(LL_WARNING|LL_RAW,
"Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
"Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.\n");
}
#endif
if (eip != NULL) {
Dl_info info;
if (dladdr(eip, &info) != 0) {
serverLog(LL_WARNING|LL_RAW,
"\n------ DUMPING CODE AROUND EIP ------\n"
"Symbol: %s (base: %p)\n"
"Module: %s (base %p)\n"
"$ xxd -r -p /tmp/dump.hex /tmp/dump.bin\n"
"$ objdump --adjust-vma=%p -D -b binary -m i386:x86-64 /tmp/dump.bin\n"
"------\n",
info.dli_sname, info.dli_saddr, info.dli_fname, info.dli_fbase,
info.dli_saddr);
size_t len = (long)eip - (long)info.dli_saddr;
unsigned long sz = sysconf(_SC_PAGESIZE);
if (len < 1<<13) { /* we don't have functions over 8k (verified) */
/* Find the address of the next page, which is our "safety"
* limit when dumping. Then try to dump just 128 bytes more
* than EIP if there is room, or stop sooner. */
unsigned long next = ((unsigned long)eip + sz) & ~(sz-1);
unsigned long end = (unsigned long)eip + 128;
if (end > next) end = next;
len = end - (unsigned long)info.dli_saddr;
serverLogHexDump(LL_WARNING, "dump of function",
info.dli_saddr ,len);
dumpX86Calls(info.dli_saddr,len);
}
}
}
serverLogRaw(LL_WARNING|LL_RAW,
"\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
" Please report the crash by opening an issue on github:\n\n"
" http://github.com/antirez/redis/issues\n\n"
" Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
);
/* free(messages); Don't call free() with possibly corrupted memory. */
if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
if (eip != NULL) {
Dl_info info;
if (dladdr(eip, &info) != 0)
{
serverLog(LL_WARNING,
"symbol: %s (base %p), in module: %s (base: %p)",
info.dli_sname, info.dli_saddr, info.dli_fname, info.dli_fbase);
size_t len = (long)eip - (long)info.dli_saddr;
long sz = sysconf(_SC_PAGESIZE);
if (len < 1<<13) { /* we don't have functions over 8k (verified) */
long end = ((long)eip + sz) & ~(sz-1); /* round up to page boundary */
len = end - (long)info.dli_saddr;
serverLogHexDump(LL_WARNING, "dump of function", info.dli_saddr ,len);
}
}
}
/* Make sure we exit with the right signal at the end. So for instance
* the core will be dumped if enabled. */
sigemptyset (&act.sa_mask);
@ -1075,7 +1114,7 @@ void serverLogHexDump(int level, char *descr, void *value, size_t len) {
unsigned char *v = value;
char charset[] = "0123456789abcdef";
serverLog(level,"%s (hexdump):", descr);
serverLog(level,"%s (hexdump of %zu bytes):", descr, len);
b = buf;
while(len) {
b[0] = charset[(*v)>>4];