From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: Stephen Hemminger <stephen@networkplumber.org>
Subject: [RFC] eal_debug: do not use malloc in rte_dump_stack
Date: Fri, 28 Jan 2022 17:10:39 -0800 [thread overview]
Message-ID: <20220129011039.264377-1-stephen@networkplumber.org> (raw)
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 <stephen@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
next reply other threads:[~2022-01-29 1:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-29 1:10 Stephen Hemminger [this message]
2022-01-29 8:25 ` Morten Brørup
2022-02-12 18:44 ` [PATCH v2 0/2] rte_dump_stack: improvements Stephen Hemminger
2022-02-12 18:44 ` [PATCH v2 1/2] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
2022-02-13 11:41 ` Thomas Monjalon
2022-03-17 23:13 ` Stephen Hemminger
2022-02-12 18:44 ` [PATCH v2 2/2] eal: common rte_dump_stack for both Linux and FreeBSD Stephen Hemminger
2022-02-14 11:10 ` [PATCH v2 0/2] rte_dump_stack: improvements Morten Brørup
2022-02-14 11:51 ` Bruce Richardson
2022-04-07 12:45 ` David Marchand
2022-04-07 23:06 ` Stephen Hemminger
2022-04-14 19:41 ` [PATCH v3] rte_dump_stack: make in async signal safe Stephen Hemminger
2022-04-14 20:19 ` [PATCH v4] " Stephen Hemminger
2022-06-23 7:51 ` David Marchand
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220129011039.264377-1-stephen@networkplumber.org \
--to=stephen@networkplumber.org \
--cc=dev@dpdk.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).