Skip to content
Browse files

Fast memory test on Redis crash.

  • Loading branch information...
1 parent 3cb4328 commit 5a9e3f58428df7d6a7a4d7cc891c95b84517183d @antirez committed
Showing with 86 additions and 0 deletions.
  1. +55 −0 src/debug.c
  2. +31 −0 src/memtest.c
View
55 src/debug.c
@@ -665,6 +665,49 @@ void logCurrentClient(void) {
}
}
+#if defined(HAVE_PROC_MAPS)
+int memtest_non_destructive(void *addr, size_t size); /* memtest.c */
+
+int memtest_test_linux_anonymous_maps(void) {
+ FILE *fp = fopen("/proc/self/maps","r");
+ char line[1024];
+ size_t start_addr, end_addr, size;
+
+ while(fgets(line,sizeof(line),fp) != NULL) {
+ char *start, *end, *p = line;
+ int j;
+
+ start = p;
+ p = strchr(p,'-');
+ if (!p) continue;
+ *p++ = '\0';
+ end = p;
+ p = strchr(p,' ');
+ if (!p) continue;
+ *p++ = '\0';
+ if (strstr(p,"stack") ||
+ strstr(p,"vdso") ||
+ strstr(p,"vsyscall")) continue;
+ if (!strstr(p,"00:00")) continue;
+ if (!strstr(p,"rw")) continue;
+
+ start_addr = strtoul(start,NULL,16);
+ end_addr = strtoul(end,NULL,16);
+ size = end_addr-start_addr;
+ redisLog(REDIS_WARNING,
+ "Testing memory at %lx (%lu bytes)", start_addr, size);
+ for (j = 0; j < 3; j++) {
+ if (memtest_non_destructive((void*)start_addr,size) != 0) {
+ fclose(fp);
+ return 1;
+ }
+ }
+ }
+ fclose(fp);
+ return 0;
+}
+#endif
+
void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
ucontext_t *uc = (ucontext_t*) secret;
sds infostring, clients;
@@ -700,6 +743,18 @@ void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
/* Log dump of processor registers */
logRegisters(uc);
+#if defined(HAVE_PROC_MAPS)
+ /* Test memory */
+ redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
+ if (memtest_test_linux_anonymous_maps()) {
+ redisLog(REDIS_WARNING,
+ "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
@anydot
anydot added a note

Shouldn't be this marked as error and not just warning?

@antirez Owner
antirez added a note

@anydot WARNING is the highest level of Redis logging, there is no ERROR level :-)

@anydot
anydot added a note

Right, seems that I'm working on too many things together to remember such a little nuances ;-)

@antirez Owner
antirez added a note

;-)

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
+ } else {
+ redisLog(REDIS_WARNING,
+ "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
+ }
+#endif
+
redisLog(REDIS_WARNING,
"\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
" Please report the crash opening an issue on github:\n\n"
View
31 src/memtest.c
@@ -35,6 +35,7 @@
#include <errno.h>
#include <termios.h>
#include <sys/ioctl.h>
+#include "config.h"
#if (ULONG_MAX == 4294967295UL)
#define MEMTEST_32BIT
@@ -240,6 +241,36 @@ void memtest_test(size_t megabytes, int passes) {
}
}
+/* This is a fast O(N) best effort memory test, only ZERO-ONE tests and
+ * checkerboard tests are performed, without pauses between setting and
+ * reading the value, so this can only detect a subclass of permanent errors.
+ *
+ * However the function does not destroy the content of the memory tested that
+ * is left unmodified.
+ *
+ * If a memory error is detected, 1 is returned. Otherwise 0 is returned. */
+int memtest_non_destructive(void *addr, size_t size) {
+ volatile unsigned long *p = addr;
+ unsigned long val;
+ size_t j;
+
+ size /= sizeof(unsigned long);
+ for (j = 0; j < size; j++) {
+ val = p[j];
+
+ p[j] = 0; if (p[j] != 0) goto err;
+ p[j] = (unsigned long)-1; if (p[j] != (unsigned long)-1) goto err;
+ p[j] = ULONG_ONEZERO; if (p[j] != ULONG_ONEZERO) goto err;
+ p[j] = ULONG_ZEROONE; if (p[j] != ULONG_ZEROONE) goto err;
+ p[j] = val; /* restore the original value. */
+ }
+ return 0;
+
+err: /* memory error detected. */
+ p[j] = val;
+ return 1;
+}
+
void memtest(size_t megabytes, int passes) {
if (ioctl(1, TIOCGWINSZ, &ws) == -1) {
ws.ws_col = 80;

0 comments on commit 5a9e3f5

Please sign in to comment.
Something went wrong with that request. Please try again.