* [RFC] eal_debug: do not use malloc in rte_dump_stack
@ 2022-01-29 1:10 Stephen Hemminger
2022-01-29 8:25 ` Morten Brørup
` (3 more replies)
0 siblings, 4 replies; 14+ messages in thread
From: Stephen Hemminger @ 2022-01-29 1:10 UTC (permalink / raw)
To: dev; +Cc: Stephen Hemminger
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
^ permalink raw reply [flat|nested] 14+ messages in thread
* RE: [RFC] eal_debug: do not use malloc in rte_dump_stack
2022-01-29 1:10 [RFC] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
@ 2022-01-29 8:25 ` Morten Brørup
2022-02-12 18:44 ` [PATCH v2 0/2] rte_dump_stack: improvements Stephen Hemminger
` (2 subsequent siblings)
3 siblings, 0 replies; 14+ messages in thread
From: Morten Brørup @ 2022-01-29 8:25 UTC (permalink / raw)
To: Stephen Hemminger, dev
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Saturday, 29 January 2022 02.11
>
> 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.
Yes. We have experienced that problem with backtrace_symbols(); so as a workaround, our failure signal handler dumps all other information first, and calls backtrace_symbols() last, in case it crashes.
>
> Instead, use dladdr() to lookup up symbols incrementally.
I took a brief look at the dladdr() source code, and it looks good to me.
>
> 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.
Good idea. Seems more logical.
>
> 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);
Probably something is lost in formatting here, but free(symb) must also be removed.
> #endif /* RTE_BACKTRACE */
> }
> --
> 2.34.1
>
Great improvement, Stephen!
Acked-by: Morten Brørup <mb@smartsharesystems.com>
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2 0/2] rte_dump_stack: improvements
2022-01-29 1:10 [RFC] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
2022-01-29 8:25 ` Morten Brørup
@ 2022-02-12 18:44 ` Stephen Hemminger
2022-02-12 18:44 ` [PATCH v2 1/2] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
` (3 more replies)
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
3 siblings, 4 replies; 14+ messages in thread
From: Stephen Hemminger @ 2022-02-12 18:44 UTC (permalink / raw)
To: dev; +Cc: Stephen Hemminger
This is update to earlier RFC. Add some more comments and changes
to have common code for Linux and FreeBSD
Stephen Hemminger (2):
eal_debug: do not use malloc in rte_dump_stack
eal: common rte_dump_stack for both Linux and FreeBSD
lib/eal/freebsd/eal_debug.c | 43 ------------------------
lib/eal/freebsd/meson.build | 1 -
lib/eal/linux/eal_debug.c | 43 ------------------------
lib/eal/linux/meson.build | 1 -
lib/eal/unix/eal_debug.c | 65 +++++++++++++++++++++++++++++++++++++
lib/eal/unix/meson.build | 5 +--
6 files changed, 68 insertions(+), 90 deletions(-)
delete mode 100644 lib/eal/freebsd/eal_debug.c
delete mode 100644 lib/eal/linux/eal_debug.c
create mode 100644 lib/eal/unix/eal_debug.c
--
2.34.1
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2 1/2] eal_debug: do not use malloc in rte_dump_stack
2022-02-12 18:44 ` [PATCH v2 0/2] rte_dump_stack: improvements Stephen Hemminger
@ 2022-02-12 18:44 ` Stephen Hemminger
2022-02-13 11:41 ` Thomas Monjalon
2022-02-12 18:44 ` [PATCH v2 2/2] eal: common rte_dump_stack for both Linux and FreeBSD Stephen Hemminger
` (2 subsequent siblings)
3 siblings, 1 reply; 14+ messages in thread
From: Stephen Hemminger @ 2022-02-12 18:44 UTC (permalink / raw)
To: dev; +Cc: Stephen Hemminger
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.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
lib/eal/linux/eal_debug.c | 46 +++++++++++++++++++++++++++++----------
1 file changed, 34 insertions(+), 12 deletions(-)
diff --git a/lib/eal/linux/eal_debug.c b/lib/eal/linux/eal_debug.c
index 64dab4e0da24..51f24e3cccdf 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 +19,47 @@
#define BACKTRACE_SIZE 256
-/* dump the stack of the calling core */
+/* Dump the stack of the calling core
+ *
+ * Note: this requires limiting what functions are used in this code to stay safe
+ * when called from a signal handler and malloc pool maybe corrupt.
+ */
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;
+ for (i = 0; i < size; i++) {
+ void *pc = func[i];
+ const char *fname;
+ Dl_info info;
- while (size > 0) {
- rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
- "%d: [%s]\n", size, symb[size - 1]);
- size --;
- }
+ if (dladdr(pc, &info) == 0) {
+ /* If symbol information not found print in hex */
+ rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+ "%d: ?? [%p]\n", i, pc);
+ continue;
+ }
- free(symb);
+ /* Is file name known? */
+ fname = (info.dli_fname && *info.dli_fname) ? info.dli_fname : "(vdso)";
+
+ /* Is symbol name known? */
+ if (info.dli_sname != 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);
+ }
#endif /* RTE_BACKTRACE */
}
--
2.34.1
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2 2/2] eal: common rte_dump_stack for both Linux and FreeBSD
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
@ 2022-02-12 18:44 ` Stephen Hemminger
2022-02-14 11:10 ` [PATCH v2 0/2] rte_dump_stack: improvements Morten Brørup
2022-04-07 12:45 ` David Marchand
3 siblings, 0 replies; 14+ messages in thread
From: Stephen Hemminger @ 2022-02-12 18:44 UTC (permalink / raw)
To: dev; +Cc: Stephen Hemminger
The core functions used by rte_dump_stack() are backtrace_symbols
and dladdr. Both of those functions are the same in Linux and
FreeBSD so the code for decoding stack should be common.
Also, the filenames unix/meson.build are now resorted.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
lib/eal/freebsd/eal_debug.c | 43 -----------------------------
lib/eal/freebsd/meson.build | 1 -
lib/eal/linux/meson.build | 1 -
lib/eal/{linux => unix}/eal_debug.c | 0
lib/eal/unix/meson.build | 5 ++--
5 files changed, 3 insertions(+), 47 deletions(-)
delete mode 100644 lib/eal/freebsd/eal_debug.c
rename lib/eal/{linux => unix}/eal_debug.c (100%)
diff --git a/lib/eal/freebsd/eal_debug.c b/lib/eal/freebsd/eal_debug.c
deleted file mode 100644
index 64dab4e0da24..000000000000
--- a/lib/eal/freebsd/eal_debug.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2014 Intel Corporation
- */
-
-#ifdef RTE_BACKTRACE
-#include <execinfo.h>
-#endif
-#include <stdarg.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-
-#include <rte_log.h>
-#include <rte_debug.h>
-#include <rte_common.h>
-#include <rte_eal.h>
-
-#define BACKTRACE_SIZE 256
-
-/* dump the stack of the calling core */
-void rte_dump_stack(void)
-{
-#ifdef RTE_BACKTRACE
- void *func[BACKTRACE_SIZE];
- char **symb = NULL;
- int 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 --;
- }
-
- free(symb);
-#endif /* RTE_BACKTRACE */
-}
diff --git a/lib/eal/freebsd/meson.build b/lib/eal/freebsd/meson.build
index 398ceab71d03..85cca5a096ca 100644
--- a/lib/eal/freebsd/meson.build
+++ b/lib/eal/freebsd/meson.build
@@ -7,7 +7,6 @@ sources += files(
'eal.c',
'eal_alarm.c',
'eal_cpuflags.c',
- 'eal_debug.c',
'eal_dev.c',
'eal_hugepage_info.c',
'eal_interrupts.c',
diff --git a/lib/eal/linux/meson.build b/lib/eal/linux/meson.build
index 65f2ac6b4798..3cccfa36c0a4 100644
--- a/lib/eal/linux/meson.build
+++ b/lib/eal/linux/meson.build
@@ -7,7 +7,6 @@ sources += files(
'eal.c',
'eal_alarm.c',
'eal_cpuflags.c',
- 'eal_debug.c',
'eal_dev.c',
'eal_hugepage_info.c',
'eal_interrupts.c',
diff --git a/lib/eal/linux/eal_debug.c b/lib/eal/unix/eal_debug.c
similarity index 100%
rename from lib/eal/linux/eal_debug.c
rename to lib/eal/unix/eal_debug.c
diff --git a/lib/eal/unix/meson.build b/lib/eal/unix/meson.build
index a22ea7cabc46..9f724bfd5d7a 100644
--- a/lib/eal/unix/meson.build
+++ b/lib/eal/unix/meson.build
@@ -2,10 +2,11 @@
# Copyright(c) 2020 Dmitry Kozlyuk
sources += files(
+ 'eal_debug.c',
'eal_file.c',
+ 'eal_filesystem.c',
+ 'eal_firmware.c',
'eal_unix_memory.c',
'eal_unix_timer.c',
- 'eal_firmware.c',
- 'eal_filesystem.c',
'rte_thread.c',
)
--
2.34.1
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 1/2] eal_debug: do not use malloc in rte_dump_stack
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
0 siblings, 1 reply; 14+ messages in thread
From: Thomas Monjalon @ 2022-02-13 11:41 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: dev, Morten Brørup
12/02/2022 19:44, Stephen Hemminger:
> 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.
>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Morten acked the RFC.
Is there any significant change?
^ permalink raw reply [flat|nested] 14+ messages in thread
* RE: [PATCH v2 0/2] rte_dump_stack: improvements
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
2022-02-12 18:44 ` [PATCH v2 2/2] eal: common rte_dump_stack for both Linux and FreeBSD Stephen Hemminger
@ 2022-02-14 11:10 ` Morten Brørup
2022-02-14 11:51 ` Bruce Richardson
2022-04-07 12:45 ` David Marchand
3 siblings, 1 reply; 14+ messages in thread
From: Morten Brørup @ 2022-02-14 11:10 UTC (permalink / raw)
To: Stephen Hemminger, dev
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Saturday, 12 February 2022 19.45
>
> This is update to earlier RFC. Add some more comments and changes
> to have common code for Linux and FreeBSD
>
> Stephen Hemminger (2):
> eal_debug: do not use malloc in rte_dump_stack
> eal: common rte_dump_stack for both Linux and FreeBSD
>
> lib/eal/freebsd/eal_debug.c | 43 ------------------------
> lib/eal/freebsd/meson.build | 1 -
> lib/eal/linux/eal_debug.c | 43 ------------------------
> lib/eal/linux/meson.build | 1 -
> lib/eal/unix/eal_debug.c | 65 +++++++++++++++++++++++++++++++++++++
> lib/eal/unix/meson.build | 5 +--
> 6 files changed, 68 insertions(+), 90 deletions(-)
> delete mode 100644 lib/eal/freebsd/eal_debug.c
> delete mode 100644 lib/eal/linux/eal_debug.c
> create mode 100644 lib/eal/unix/eal_debug.c
>
> --
> 2.34.1
>
The dladdr() man page mentions that linking with -ldl is required; I assume this is already part of the DPDK EAL build system?
For the series,
Acked-by: Morten Brørup <mb@smartsharesystems.com>
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 0/2] rte_dump_stack: improvements
2022-02-14 11:10 ` [PATCH v2 0/2] rte_dump_stack: improvements Morten Brørup
@ 2022-02-14 11:51 ` Bruce Richardson
0 siblings, 0 replies; 14+ messages in thread
From: Bruce Richardson @ 2022-02-14 11:51 UTC (permalink / raw)
To: Morten Brørup; +Cc: Stephen Hemminger, dev
On Mon, Feb 14, 2022 at 12:10:30PM +0100, Morten Brørup wrote:
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Saturday, 12 February 2022 19.45
> >
> > This is update to earlier RFC. Add some more comments and changes
> > to have common code for Linux and FreeBSD
> >
> > Stephen Hemminger (2):
> > eal_debug: do not use malloc in rte_dump_stack
> > eal: common rte_dump_stack for both Linux and FreeBSD
> >
> > lib/eal/freebsd/eal_debug.c | 43 ------------------------
> > lib/eal/freebsd/meson.build | 1 -
> > lib/eal/linux/eal_debug.c | 43 ------------------------
> > lib/eal/linux/meson.build | 1 -
> > lib/eal/unix/eal_debug.c | 65 +++++++++++++++++++++++++++++++++++++
> > lib/eal/unix/meson.build | 5 +--
> > 6 files changed, 68 insertions(+), 90 deletions(-)
> > delete mode 100644 lib/eal/freebsd/eal_debug.c
> > delete mode 100644 lib/eal/linux/eal_debug.c
> > create mode 100644 lib/eal/unix/eal_debug.c
> >
> > --
> > 2.34.1
> >
>
> The dladdr() man page mentions that linking with -ldl is required; I assume this is already part of the DPDK EAL build system?
>
Yes, we should be already linking against dl because of the use of dlopen
for loading drivers dynamically.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 1/2] eal_debug: do not use malloc in rte_dump_stack
2022-02-13 11:41 ` Thomas Monjalon
@ 2022-03-17 23:13 ` Stephen Hemminger
0 siblings, 0 replies; 14+ messages in thread
From: Stephen Hemminger @ 2022-03-17 23:13 UTC (permalink / raw)
To: Thomas Monjalon; +Cc: dev, Morten Brørup
On Sun, 13 Feb 2022 12:41:59 +0100
Thomas Monjalon <thomas@monjalon.net> wrote:
> 12/02/2022 19:44, Stephen Hemminger:
> > 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.
> >
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
>
> Morten acked the RFC.
> Is there any significant change?
>
>
>
The change was making it not RFC.
Lets make a common code for this FreeBSD should have same code.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 0/2] rte_dump_stack: improvements
2022-02-12 18:44 ` [PATCH v2 0/2] rte_dump_stack: improvements Stephen Hemminger
` (2 preceding siblings ...)
2022-02-14 11:10 ` [PATCH v2 0/2] rte_dump_stack: improvements Morten Brørup
@ 2022-04-07 12:45 ` David Marchand
2022-04-07 23:06 ` Stephen Hemminger
3 siblings, 1 reply; 14+ messages in thread
From: David Marchand @ 2022-04-07 12:45 UTC (permalink / raw)
To: Stephen Hemminger
Cc: dev, Morten Brørup, Bruce Richardson, Thomas Monjalon
On Sat, Feb 12, 2022 at 7:44 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> This is update to earlier RFC. Add some more comments and changes
> to have common code for Linux and FreeBSD
>
> Stephen Hemminger (2):
> eal_debug: do not use malloc in rte_dump_stack
> eal: common rte_dump_stack for both Linux and FreeBSD
>
> lib/eal/freebsd/eal_debug.c | 43 ------------------------
> lib/eal/freebsd/meson.build | 1 -
> lib/eal/linux/eal_debug.c | 43 ------------------------
> lib/eal/linux/meson.build | 1 -
> lib/eal/unix/eal_debug.c | 65 +++++++++++++++++++++++++++++++++++++
> lib/eal/unix/meson.build | 5 +--
> 6 files changed, 68 insertions(+), 90 deletions(-)
> delete mode 100644 lib/eal/freebsd/eal_debug.c
> delete mode 100644 lib/eal/linux/eal_debug.c
> create mode 100644 lib/eal/unix/eal_debug.c
Strange to change only the Linux implementation as a first patch, then
merge implementations in a second time effectively changing FreeBSD
implementation in what is presented in commitlog as a factorisation
cleanup.
Please invert the patches.
Besides, the series does not compile on current main.
It's probably a result of the header inclusion cleanup we had in
v22.03, but I prefer you check.
Thanks.
--
David Marchand
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 0/2] rte_dump_stack: improvements
2022-04-07 12:45 ` David Marchand
@ 2022-04-07 23:06 ` Stephen Hemminger
0 siblings, 0 replies; 14+ messages in thread
From: Stephen Hemminger @ 2022-04-07 23:06 UTC (permalink / raw)
To: David Marchand; +Cc: dev, Morten Brørup, Bruce Richardson, Thomas Monjalon
On Thu, 7 Apr 2022 14:45:07 +0200
David Marchand <david.marchand@redhat.com> wrote:
> On Sat, Feb 12, 2022 at 7:44 PM Stephen Hemminger
> <stephen@networkplumber.org> wrote:
> >
> > This is update to earlier RFC. Add some more comments and changes
> > to have common code for Linux and FreeBSD
> >
> > Stephen Hemminger (2):
> > eal_debug: do not use malloc in rte_dump_stack
> > eal: common rte_dump_stack for both Linux and FreeBSD
> >
> > lib/eal/freebsd/eal_debug.c | 43 ------------------------
> > lib/eal/freebsd/meson.build | 1 -
> > lib/eal/linux/eal_debug.c | 43 ------------------------
> > lib/eal/linux/meson.build | 1 -
> > lib/eal/unix/eal_debug.c | 65 +++++++++++++++++++++++++++++++++++++
> > lib/eal/unix/meson.build | 5 +--
> > 6 files changed, 68 insertions(+), 90 deletions(-)
> > delete mode 100644 lib/eal/freebsd/eal_debug.c
> > delete mode 100644 lib/eal/linux/eal_debug.c
> > create mode 100644 lib/eal/unix/eal_debug.c
>
> Strange to change only the Linux implementation as a first patch, then
> merge implementations in a second time effectively changing FreeBSD
> implementation in what is presented in commitlog as a factorisation
> cleanup.
> Please invert the patches.
>
> Besides, the series does not compile on current main.
> It's probably a result of the header inclusion cleanup we had in
> v22.03, but I prefer you check.
>
>
> Thanks.
As I looked at it more, there was more there.
Turns out that printf and therefore rte_log() is not signal safe.
There is a version of backtrace_symbols_fd that just uses writev() on glibc for Linux
so that is a better alternative, but format changes.
But the BSD version of backtrace_symbols_fd uses printf and is therefore not signal safe.
Not sure if that matters.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v3] rte_dump_stack: make in async signal safe
2022-01-29 1:10 [RFC] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
2022-01-29 8:25 ` Morten Brørup
2022-02-12 18:44 ` [PATCH v2 0/2] rte_dump_stack: improvements Stephen Hemminger
@ 2022-04-14 19:41 ` Stephen Hemminger
2022-04-14 20:19 ` [PATCH v4] " Stephen Hemminger
3 siblings, 0 replies; 14+ messages in thread
From: Stephen Hemminger @ 2022-04-14 19:41 UTC (permalink / raw)
To: dev; +Cc: Stephen Hemminger, Morten Brørup, Bruce Richardson
rte_dump_stack needs to be usable in situations when a bug is
encountered and from signal handlers (such as SEGV).
Glibc backtrace_symbols() calls malloc which makes it
dangerous in a signal handler that is handling errors that maybe
due to memory corruption. Additionally, rte_log() is unsafe because
syslog() is not signal safe; printf() is also documented as
not being safe.
This version formats message and uses writev for each line in a manner
similar to what glibc version of backtrace_symbols_fd() does. The
FreeBSD version of backtrace_symbols_fd() is not signal safe.
Sample output:
0: ./build/app/dpdk-testpmd (rte_dump_stack+0x2b) [560a6e9c002b]
1: ./build/app/dpdk-testpmd (main+0xad) [560a6decd5ad]
2: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xcd) [7fd43d3e27fd]
3: ./build/app/dpdk-testpmd (_start+0x2a) [560a6e83628a]
Bugzilla ID: 929
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
v3
- merge previous two patches into one
common Linux/FreeBSD code.
- rewrite the code to not use functions which are not
documented to be signal safe.
lib/eal/freebsd/eal_debug.c | 43 -------------
lib/eal/freebsd/meson.build | 1 -
lib/eal/include/rte_debug.h | 2 +-
lib/eal/linux/eal_debug.c | 38 -----------
lib/eal/linux/meson.build | 1 -
lib/eal/unix/eal_debug.c | 123 ++++++++++++++++++++++++++++++++++++
lib/eal/unix/meson.build | 1 +
7 files changed, 125 insertions(+), 84 deletions(-)
delete mode 100644 lib/eal/freebsd/eal_debug.c
delete mode 100644 lib/eal/linux/eal_debug.c
create mode 100644 lib/eal/unix/eal_debug.c
diff --git a/lib/eal/freebsd/eal_debug.c b/lib/eal/freebsd/eal_debug.c
deleted file mode 100644
index 64dab4e0da24..000000000000
--- a/lib/eal/freebsd/eal_debug.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2014 Intel Corporation
- */
-
-#ifdef RTE_BACKTRACE
-#include <execinfo.h>
-#endif
-#include <stdarg.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-
-#include <rte_log.h>
-#include <rte_debug.h>
-#include <rte_common.h>
-#include <rte_eal.h>
-
-#define BACKTRACE_SIZE 256
-
-/* dump the stack of the calling core */
-void rte_dump_stack(void)
-{
-#ifdef RTE_BACKTRACE
- void *func[BACKTRACE_SIZE];
- char **symb = NULL;
- int 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 --;
- }
-
- free(symb);
-#endif /* RTE_BACKTRACE */
-}
diff --git a/lib/eal/freebsd/meson.build b/lib/eal/freebsd/meson.build
index 398ceab71d03..85cca5a096ca 100644
--- a/lib/eal/freebsd/meson.build
+++ b/lib/eal/freebsd/meson.build
@@ -7,7 +7,6 @@ sources += files(
'eal.c',
'eal_alarm.c',
'eal_cpuflags.c',
- 'eal_debug.c',
'eal_dev.c',
'eal_hugepage_info.c',
'eal_interrupts.c',
diff --git a/lib/eal/include/rte_debug.h b/lib/eal/include/rte_debug.h
index c4bc71ce28f5..2c4b94a7c9bf 100644
--- a/lib/eal/include/rte_debug.h
+++ b/lib/eal/include/rte_debug.h
@@ -22,7 +22,7 @@ extern "C" {
#endif
/**
- * Dump the stack of the calling core to the console.
+ * Dump the stack of the calling core to the standard error.
*/
void rte_dump_stack(void);
diff --git a/lib/eal/linux/eal_debug.c b/lib/eal/linux/eal_debug.c
deleted file mode 100644
index b0ecf5a9dcde..000000000000
--- a/lib/eal/linux/eal_debug.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2014 Intel Corporation
- */
-
-#ifdef RTE_BACKTRACE
-#include <execinfo.h>
-#endif
-#include <stdlib.h>
-#include <stdio.h>
-
-#include <rte_log.h>
-#include <rte_debug.h>
-
-#define BACKTRACE_SIZE 256
-
-/* dump the stack of the calling core */
-void rte_dump_stack(void)
-{
-#ifdef RTE_BACKTRACE
- void *func[BACKTRACE_SIZE];
- char **symb = NULL;
- int 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 --;
- }
-
- free(symb);
-#endif /* RTE_BACKTRACE */
-}
diff --git a/lib/eal/linux/meson.build b/lib/eal/linux/meson.build
index 65f2ac6b4798..3cccfa36c0a4 100644
--- a/lib/eal/linux/meson.build
+++ b/lib/eal/linux/meson.build
@@ -7,7 +7,6 @@ sources += files(
'eal.c',
'eal_alarm.c',
'eal_cpuflags.c',
- 'eal_debug.c',
'eal_dev.c',
'eal_hugepage_info.c',
'eal_interrupts.c',
diff --git a/lib/eal/unix/eal_debug.c b/lib/eal/unix/eal_debug.c
new file mode 100644
index 000000000000..79b6f2fea2b9
--- /dev/null
+++ b/lib/eal/unix/eal_debug.c
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation
+ */
+
+#include <rte_debug.h>
+
+
+#ifdef RTE_BACKTRACE
+
+#include <dlfcn.h>
+#include <execinfo.h>
+#include <string.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#define BACKTRACE_SIZE 256
+
+/*
+ * Convert number to string and return start of string.
+ * Note: string does not start at beginning of buffer.
+ */
+static char *safe_itoa(long val, char *buf, size_t len, unsigned int radix)
+{
+ char *bp = buf + len;
+ static const char hexdigit[] = "0123456789abcdef";
+
+ *--bp = '\0'; /* Null terminate the string */
+ do {
+ /* if buffer is not big enough, then truncate */
+ if (bp == buf)
+ return bp;
+
+ *--bp = hexdigit[val % radix];
+ val /= radix;
+ } while (val != 0);
+
+ return bp;
+}
+
+
+/* Dump the stack of the calling core
+ *
+ * To be safe in signal handler requires limiting what functions are
+ * used in this code since may be called from inside libc or
+ * when malloc poll is corrupt.
+ *
+ * Most of libc is therefore not safe, include RTE_LOG (calls syslog);
+ * backtrace_symbols (calls malloc), etc.
+ */
+void rte_dump_stack(void)
+{
+ void *func[BACKTRACE_SIZE];
+ Dl_info info;
+ char buf1[8], buf2[32], buf3[32], buf4[32];
+ struct iovec iov[10];
+ int i, size;
+
+ size = backtrace(func, BACKTRACE_SIZE);
+
+ for (i = 0; i < size; i++) {
+ struct iovec *io = iov;
+ char *str;
+ uintptr_t base;
+ long offset;
+ void *pc = func[i];
+
+/* Macro to put string onto set of iovecs
+ * cast is to suppress warnings about lose of const qualifier
+ */
+#define PUSH_IOV(io, str) { \
+ (io)->iov_base = (char *)(uintptr_t)str; \
+ (io)->iov_len = strlen(str); \
+ ++io; }
+
+ /* output stack frame number */
+ str = safe_itoa(i, buf1, sizeof(buf1), 10);
+ PUSH_IOV(io, str); /* iov[0] */
+ PUSH_IOV(io, ": "); /* iov[1] */
+
+ /* Lookup the symbol information */
+ if (dladdr (pc, &info) == 0) {
+ PUSH_IOV(io, "?? [");
+ } else {
+ const char *fname;
+
+ if (info.dli_fname && *info.dli_fname)
+ fname = info.dli_fname;
+ else
+ fname = "(vdso)";
+ PUSH_IOV(io, fname); /* iov[2] */
+ PUSH_IOV(io, " ("); /* iov[3] */
+
+ if (info.dli_saddr != NULL) {
+ PUSH_IOV(io, info.dli_sname); /* iov[4] */
+ base = (uintptr_t)info.dli_saddr;
+ } else {
+ str = safe_itoa((unsigned long)info.dli_fbase,
+ buf3, sizeof(buf3), 16);
+ PUSH_IOV(io, str);
+ base = (uintptr_t)info.dli_fbase;
+ }
+
+ PUSH_IOV(io, "+0x"); /* iov[5] */
+
+ offset = (uintptr_t)pc - base;
+ str = safe_itoa(offset, buf4, sizeof(buf4), 16);
+ PUSH_IOV(io, str); /* iov[6] */
+
+ PUSH_IOV(io, ") ["); /* iov[7] */
+ }
+
+ str = safe_itoa((unsigned long)pc, buf2, sizeof(buf2), 16);
+ PUSH_IOV(io, str); /* iov[8] */
+ PUSH_IOV(io, "]\n"); /* iov[9] */
+
+ if (writev(STDERR_FILENO, iov, io - iov) < 0)
+ break;
+ }
+}
+#else
+/* stub if not enabled */
+void rte_dump_stack(void) { }
+#endif /* RTE_BACKTRACE */
diff --git a/lib/eal/unix/meson.build b/lib/eal/unix/meson.build
index a22ea7cabc46..9c59f3d31693 100644
--- a/lib/eal/unix/meson.build
+++ b/lib/eal/unix/meson.build
@@ -2,6 +2,7 @@
# Copyright(c) 2020 Dmitry Kozlyuk
sources += files(
+ 'eal_debug.c',
'eal_file.c',
'eal_unix_memory.c',
'eal_unix_timer.c',
--
2.35.1
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v4] rte_dump_stack: make in async signal safe
2022-01-29 1:10 [RFC] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
` (2 preceding siblings ...)
2022-04-14 19:41 ` [PATCH v3] rte_dump_stack: make in async signal safe Stephen Hemminger
@ 2022-04-14 20:19 ` Stephen Hemminger
2022-06-23 7:51 ` David Marchand
3 siblings, 1 reply; 14+ messages in thread
From: Stephen Hemminger @ 2022-04-14 20:19 UTC (permalink / raw)
To: dev; +Cc: Stephen Hemminger, Morten Brørup, Bruce Richardson
rte_dump_stack() needs to be usable in situations when a bug is
encountered and from signal handlers (such as SEGV).
Glibc backtrace_symbols() calls malloc which makes it
dangerous in a signal handler that is handling errors that maybe
due to memory corruption. Additionally, rte_log() is unsafe because
syslog() is not signal safe; printf() is also documented as
not being safe.
This version formats message and uses writev for each line in a manner
similar to what glibc version of backtrace_symbols_fd() does. The
FreeBSD version of backtrace_symbols_fd() is not signal safe.
Sample output:
0: ./build/app/dpdk-testpmd (rte_dump_stack+0x2b) [560a6e9c002b]
1: ./build/app/dpdk-testpmd (main+0xad) [560a6decd5ad]
2: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xcd) [7fd43d3e27fd]
3: ./build/app/dpdk-testpmd (_start+0x2a) [560a6e83628a]
Bugzilla ID: 929
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
v4
- fix whitespace report from checkpatch
v3
- merge previous two patches into one
common Linux/FreeBSD code.
- rewrite the code to not use functions which are not
documented to be signal safe.
lib/eal/freebsd/eal_debug.c | 43 -------------
lib/eal/freebsd/meson.build | 1 -
lib/eal/include/rte_debug.h | 2 +-
lib/eal/linux/eal_debug.c | 38 -----------
lib/eal/linux/meson.build | 1 -
lib/eal/unix/eal_debug.c | 123 ++++++++++++++++++++++++++++++++++++
lib/eal/unix/meson.build | 1 +
7 files changed, 125 insertions(+), 84 deletions(-)
delete mode 100644 lib/eal/freebsd/eal_debug.c
delete mode 100644 lib/eal/linux/eal_debug.c
create mode 100644 lib/eal/unix/eal_debug.c
diff --git a/lib/eal/freebsd/eal_debug.c b/lib/eal/freebsd/eal_debug.c
deleted file mode 100644
index 64dab4e0da24..000000000000
--- a/lib/eal/freebsd/eal_debug.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2014 Intel Corporation
- */
-
-#ifdef RTE_BACKTRACE
-#include <execinfo.h>
-#endif
-#include <stdarg.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-
-#include <rte_log.h>
-#include <rte_debug.h>
-#include <rte_common.h>
-#include <rte_eal.h>
-
-#define BACKTRACE_SIZE 256
-
-/* dump the stack of the calling core */
-void rte_dump_stack(void)
-{
-#ifdef RTE_BACKTRACE
- void *func[BACKTRACE_SIZE];
- char **symb = NULL;
- int 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 --;
- }
-
- free(symb);
-#endif /* RTE_BACKTRACE */
-}
diff --git a/lib/eal/freebsd/meson.build b/lib/eal/freebsd/meson.build
index 398ceab71d03..85cca5a096ca 100644
--- a/lib/eal/freebsd/meson.build
+++ b/lib/eal/freebsd/meson.build
@@ -7,7 +7,6 @@ sources += files(
'eal.c',
'eal_alarm.c',
'eal_cpuflags.c',
- 'eal_debug.c',
'eal_dev.c',
'eal_hugepage_info.c',
'eal_interrupts.c',
diff --git a/lib/eal/include/rte_debug.h b/lib/eal/include/rte_debug.h
index c4bc71ce28f5..2c4b94a7c9bf 100644
--- a/lib/eal/include/rte_debug.h
+++ b/lib/eal/include/rte_debug.h
@@ -22,7 +22,7 @@ extern "C" {
#endif
/**
- * Dump the stack of the calling core to the console.
+ * Dump the stack of the calling core to the standard error.
*/
void rte_dump_stack(void);
diff --git a/lib/eal/linux/eal_debug.c b/lib/eal/linux/eal_debug.c
deleted file mode 100644
index b0ecf5a9dcde..000000000000
--- a/lib/eal/linux/eal_debug.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2014 Intel Corporation
- */
-
-#ifdef RTE_BACKTRACE
-#include <execinfo.h>
-#endif
-#include <stdlib.h>
-#include <stdio.h>
-
-#include <rte_log.h>
-#include <rte_debug.h>
-
-#define BACKTRACE_SIZE 256
-
-/* dump the stack of the calling core */
-void rte_dump_stack(void)
-{
-#ifdef RTE_BACKTRACE
- void *func[BACKTRACE_SIZE];
- char **symb = NULL;
- int 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 --;
- }
-
- free(symb);
-#endif /* RTE_BACKTRACE */
-}
diff --git a/lib/eal/linux/meson.build b/lib/eal/linux/meson.build
index 65f2ac6b4798..3cccfa36c0a4 100644
--- a/lib/eal/linux/meson.build
+++ b/lib/eal/linux/meson.build
@@ -7,7 +7,6 @@ sources += files(
'eal.c',
'eal_alarm.c',
'eal_cpuflags.c',
- 'eal_debug.c',
'eal_dev.c',
'eal_hugepage_info.c',
'eal_interrupts.c',
diff --git a/lib/eal/unix/eal_debug.c b/lib/eal/unix/eal_debug.c
new file mode 100644
index 000000000000..dea7372af2f8
--- /dev/null
+++ b/lib/eal/unix/eal_debug.c
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation
+ */
+
+#include <rte_debug.h>
+
+
+#ifdef RTE_BACKTRACE
+
+#include <dlfcn.h>
+#include <execinfo.h>
+#include <string.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#define BACKTRACE_SIZE 256
+
+/*
+ * Convert number to string and return start of string.
+ * Note: string does not start at beginning of buffer.
+ */
+static char *safe_itoa(long val, char *buf, size_t len, unsigned int radix)
+{
+ char *bp = buf + len;
+ static const char hexdigit[] = "0123456789abcdef";
+
+ *--bp = '\0'; /* Null terminate the string */
+ do {
+ /* if buffer is not big enough, then truncate */
+ if (bp == buf)
+ return bp;
+
+ *--bp = hexdigit[val % radix];
+ val /= radix;
+ } while (val != 0);
+
+ return bp;
+}
+
+
+/* Dump the stack of the calling core
+ *
+ * To be safe in signal handler requires limiting what functions are
+ * used in this code since may be called from inside libc or
+ * when malloc poll is corrupt.
+ *
+ * Most of libc is therefore not safe, include RTE_LOG (calls syslog);
+ * backtrace_symbols (calls malloc), etc.
+ */
+void rte_dump_stack(void)
+{
+ void *func[BACKTRACE_SIZE];
+ Dl_info info;
+ char buf1[8], buf2[32], buf3[32], buf4[32];
+ struct iovec iov[10];
+ int i, size;
+
+ size = backtrace(func, BACKTRACE_SIZE);
+
+ for (i = 0; i < size; i++) {
+ struct iovec *io = iov;
+ char *str;
+ uintptr_t base;
+ long offset;
+ void *pc = func[i];
+
+/* Macro to put string onto set of iovecs
+ * cast is to suppress warnings about lose of const qualifier
+ */
+#define PUSH_IOV(io, str) { \
+ (io)->iov_base = (char *)(uintptr_t)str; \
+ (io)->iov_len = strlen(str); \
+ ++io; }
+
+ /* output stack frame number */
+ str = safe_itoa(i, buf1, sizeof(buf1), 10);
+ PUSH_IOV(io, str); /* iov[0] */
+ PUSH_IOV(io, ": "); /* iov[1] */
+
+ /* Lookup the symbol information */
+ if (dladdr(pc, &info) == 0) {
+ PUSH_IOV(io, "?? [");
+ } else {
+ const char *fname;
+
+ if (info.dli_fname && *info.dli_fname)
+ fname = info.dli_fname;
+ else
+ fname = "(vdso)";
+ PUSH_IOV(io, fname); /* iov[2] */
+ PUSH_IOV(io, " ("); /* iov[3] */
+
+ if (info.dli_saddr != NULL) {
+ PUSH_IOV(io, info.dli_sname); /* iov[4] */
+ base = (uintptr_t)info.dli_saddr;
+ } else {
+ str = safe_itoa((unsigned long)info.dli_fbase,
+ buf3, sizeof(buf3), 16);
+ PUSH_IOV(io, str);
+ base = (uintptr_t)info.dli_fbase;
+ }
+
+ PUSH_IOV(io, "+0x"); /* iov[5] */
+
+ offset = (uintptr_t)pc - base;
+ str = safe_itoa(offset, buf4, sizeof(buf4), 16);
+ PUSH_IOV(io, str); /* iov[6] */
+
+ PUSH_IOV(io, ") ["); /* iov[7] */
+ }
+
+ str = safe_itoa((unsigned long)pc, buf2, sizeof(buf2), 16);
+ PUSH_IOV(io, str); /* iov[8] */
+ PUSH_IOV(io, "]\n"); /* iov[9] */
+
+ if (writev(STDERR_FILENO, iov, io - iov) < 0)
+ break;
+ }
+}
+#else
+/* stub if not enabled */
+void rte_dump_stack(void) { }
+#endif /* RTE_BACKTRACE */
diff --git a/lib/eal/unix/meson.build b/lib/eal/unix/meson.build
index 781505ca9061..cc7d67dd321d 100644
--- a/lib/eal/unix/meson.build
+++ b/lib/eal/unix/meson.build
@@ -2,6 +2,7 @@
# Copyright(c) 2020 Dmitry Kozlyuk
sources += files(
+ 'eal_debug.c',
'eal_file.c',
'eal_filesystem.c',
'eal_firmware.c',
--
2.35.1
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4] rte_dump_stack: make in async signal safe
2022-04-14 20:19 ` [PATCH v4] " Stephen Hemminger
@ 2022-06-23 7:51 ` David Marchand
0 siblings, 0 replies; 14+ messages in thread
From: David Marchand @ 2022-06-23 7:51 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: dev, Morten Brørup, Bruce Richardson
On Thu, Apr 14, 2022 at 10:19 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> rte_dump_stack() needs to be usable in situations when a bug is
> encountered and from signal handlers (such as SEGV).
>
> Glibc backtrace_symbols() calls malloc which makes it
> dangerous in a signal handler that is handling errors that maybe
> due to memory corruption. Additionally, rte_log() is unsafe because
> syslog() is not signal safe; printf() is also documented as
> not being safe.
>
> This version formats message and uses writev for each line in a manner
> similar to what glibc version of backtrace_symbols_fd() does. The
> FreeBSD version of backtrace_symbols_fd() is not signal safe.
>
> Sample output:
>
> 0: ./build/app/dpdk-testpmd (rte_dump_stack+0x2b) [560a6e9c002b]
> 1: ./build/app/dpdk-testpmd (main+0xad) [560a6decd5ad]
> 2: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xcd) [7fd43d3e27fd]
> 3: ./build/app/dpdk-testpmd (_start+0x2a) [560a6e83628a]
>
> Bugzilla ID: 929
> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: David Marchand <david.marchand@redhat.com>
Applied, thanks.
--
David Marchand
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2022-06-23 7:51 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-29 1:10 [RFC] eal_debug: do not use malloc in rte_dump_stack Stephen Hemminger
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
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