The glibc backtrace_symbols() calls malloc which makes it
dangerous to use rte_dump_stack() in a signal handler that
is handling errors that maybe due to memory corruption.
Instead, use dladdr() to lookup up symbols incrementally.
The format of the messages is based on what X org server
has been doing for many years. It changes from bottom up
to top down order.
Bugzilla ID: 929
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
lib/eal/linux/eal_debug.c | 45 ++++++++++++++++++++++++++++-----------
1 file changed, 32 insertions(+), 13 deletions(-)
diff --git a/lib/eal/linux/eal_debug.c b/lib/eal/linux/eal_debug.c
index 64dab4e0da24..bf232f72f402 100644
--- a/lib/eal/linux/eal_debug.c
+++ b/lib/eal/linux/eal_debug.c
@@ -4,6 +4,7 @@
#ifdef RTE_BACKTRACE
#include <execinfo.h>
+#include <dlfcn.h>
#endif
#include <stdarg.h>
#include <signal.h>
@@ -18,26 +19,44 @@
#define BACKTRACE_SIZE 256
-/* dump the stack of the calling core */
+/* Dump the stack of the calling core
+ *
+ * Note: this requires some careful usage in order to
+ * stay safe in case where called from a signal
+ * handler and the malloc pool may be corrupted.
+ */
void rte_dump_stack(void)
{
#ifdef RTE_BACKTRACE
void *func[BACKTRACE_SIZE];
- char **symb = NULL;
- int size;
+ int i, size;
size = backtrace(func, BACKTRACE_SIZE);
- symb = backtrace_symbols(func, size);
-
- if (symb == NULL)
- return;
- while (size > 0) {
- rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
- "%d: [%s]\n", size, symb[size - 1]);
- size --;
+ for (i = 0; i < size; i++) {
+ void *pc = func[i];
+ const char *fname;
+ Dl_info info;
+
+ if (dladdr(pc, &info) == 0) {
+ rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+ "%d: ?? [%p]\n", i, pc);
+ continue;
+ }
+
+ fname = (info.dli_fname && *info.dli_fname) ? info.dli_fname :
"(vdso)";
+ if (info.dli_saddr != NULL)
+ rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+ "%d: %s (%s+%#tx) [%p]\n",
+ i, fname, info.dli_sname,
+ (ptrdiff_t)((uintptr_t)pc -
(uintptr_t)info.dli_saddr),
+ pc);
+ else
+ rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+ "%d: %s (%p+%#tx) [%p]\n",
+ i, fname, info.dli_fbase,
+ (ptrdiff_t)((uintptr_t)pc -
(uintptr_t)info.dli_fbase),
+ pc);
}
-
free(symb);
#endif /* RTE_BACKTRACE */
}
--
2.34.1
