diff mbox series

[v5] lib/eal: fix segfaults in exiting

Message ID 20220906025132.160801-1-zhichaox.zeng@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers show
Series [v5] lib/eal: fix segfaults in exiting | expand

Checks

Context Check Description
ci/intel-Testing success Testing PASS
ci/Intel-compilation fail Compilation issues
ci/checkpatch warning coding style issues

Commit Message

Zhichao Zeng Sept. 6, 2022, 2:51 a.m. UTC
The 'eal-intr-thread' is not closed before memory cleanup in the process of
exiting. There is a small chance that the 'eal-intr-thread' is about to use
some pointers, the memory was just cleaned, which causes segfaults
caught by ASan.

This patch closes the 'eal-intr-thread' before memory cleanup in
'rte_eal_cleanup' to avoid segfaults, and adds a flag to avoid executing
'rte_eal_cleanup' in the child process which is forked to execut some
test cases(e.g. debug_autotest of dpdk-test).

Bugzilla ID: 1006
Cc: stable@dpdk.org

Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>

---
v2: add same API for FreeBSD
---
v3: fix rte_eal_cleanup crash in debug_autotest
---
v4: shorten the prompt message and optimize the commit log
---
v5: simplify patch
---
 lib/eal/common/eal_private.h     |  7 +++++++
 lib/eal/freebsd/eal.c            | 13 +++++++++++++
 lib/eal/freebsd/eal_interrupts.c | 12 ++++++++++++
 lib/eal/linux/eal.c              | 13 +++++++++++++
 lib/eal/linux/eal_interrupts.c   | 12 ++++++++++++
 5 files changed, 57 insertions(+)

Comments

Stephen Hemminger Sept. 6, 2022, 3:03 p.m. UTC | #1
On Tue,  6 Sep 2022 10:51:31 +0800
Zhichao Zeng <zhichaox.zeng@intel.com> wrote:

>  
> +static void mark_forked(void)
> +{
> +	is_forked++;
> +}
> +

This will end up counting application threads as well.

Also, it would need to be atomic.

>  /* Launch threads, called at application init(). */
>  int
>  rte_eal_init(int argc, char **argv)
> @@ -1324,6 +1331,8 @@ rte_eal_init(int argc, char **argv)
>  
>  	eal_mcfg_complete();
>  
> +	pthread_atfork(NULL, NULL, mark_forked);
> +
>  	return fctret;
>  }

>  int
>  rte_eal_cleanup(void)
>  {
> +	if (is_forked)
> +		return 0;
> +

rte_eal_cleanup is supposed to be called only once by application.
Zhichao Zeng Sept. 7, 2022, 8:53 a.m. UTC | #2
Hi Stephen,

> >
> > +static void mark_forked(void)
> > +{
> > +	is_forked++;
> > +}
> > +
> 
> This will end up counting application threads as well.
> 

I think it would be counted in the child process when 'fork()' is called,
and in the parent process, it would be zero.

> Also, it would need to be atomic.
> 

Thanks for your advice.

> >  /* Launch threads, called at application init(). */  int
> > rte_eal_init(int argc, char **argv) @@ -1324,6 +1331,8 @@
> > rte_eal_init(int argc, char **argv)
> >
> >  	eal_mcfg_complete();
> >
> > +	pthread_atfork(NULL, NULL, mark_forked);
> > +
> >  	return fctret;
> >  }
> 
> >  int
> >  rte_eal_cleanup(void)
> >  {
> > +	if (is_forked)
> > +		return 0;
> > +
> 
> rte_eal_cleanup is supposed to be called only once by application.

Yes. But in some case(e.g. debug_autotest of dpdk-test), it would fork
a child process to test 'rte_exit()', then it would call 'rte_eal_cleanup()'.
So 'is_forked' is introduced to avoid this situation.

Regards
Zhichao
diff mbox series

Patch

diff --git a/lib/eal/common/eal_private.h b/lib/eal/common/eal_private.h
index 44d14241f0..7adf41b7d7 100644
--- a/lib/eal/common/eal_private.h
+++ b/lib/eal/common/eal_private.h
@@ -152,6 +152,13 @@  int rte_eal_tailqs_init(void);
  */
 int rte_eal_intr_init(void);
 
+/**
+ * Destroy interrupt handling thread.
+ *
+ * This function is private to EAL.
+ */
+void rte_eal_intr_destroy(void);
+
 /**
  * Close the default log stream
  *
diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index 26fbc91b26..f27c1d9f97 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -72,6 +72,8 @@  struct lcore_config lcore_config[RTE_MAX_LCORE];
 /* used by rte_rdtsc() */
 int rte_cycles_vmware_tsc_map;
 
+/* used to judge if is forked */
+static int is_forked;
 
 int
 eal_clean_runtime_dir(void)
@@ -574,6 +576,11 @@  static void rte_eal_init_alert(const char *msg)
 	RTE_LOG(ERR, EAL, "%s\n", msg);
 }
 
+static void mark_forked(void)
+{
+	is_forked++;
+}
+
 /* Launch threads, called at application init(). */
 int
 rte_eal_init(int argc, char **argv)
@@ -883,16 +890,22 @@  rte_eal_init(int argc, char **argv)
 
 	eal_mcfg_complete();
 
+	pthread_atfork(NULL, NULL, mark_forked);
+
 	return fctret;
 }
 
 int
 rte_eal_cleanup(void)
 {
+	if (is_forked)
+		return 0;
+
 	struct internal_config *internal_conf =
 		eal_get_internal_configuration();
 	rte_service_finalize();
 	rte_mp_channel_cleanup();
+	rte_eal_intr_destroy();
 	rte_trace_save();
 	eal_trace_fini();
 	/* after this point, any DPDK pointers will become dangling */
diff --git a/lib/eal/freebsd/eal_interrupts.c b/lib/eal/freebsd/eal_interrupts.c
index 9f720bdc8f..cac3859b06 100644
--- a/lib/eal/freebsd/eal_interrupts.c
+++ b/lib/eal/freebsd/eal_interrupts.c
@@ -648,6 +648,18 @@  rte_eal_intr_init(void)
 	return ret;
 }
 
+void
+rte_eal_intr_destroy(void)
+{
+	/* cancel the host thread to wait/handle the interrupt */
+	pthread_cancel(intr_thread);
+	pthread_join(intr_thread, NULL);
+
+	/* close kqueue */
+	close(kq);
+	kq = -1;
+}
+
 int
 rte_intr_rx_ctl(struct rte_intr_handle *intr_handle,
 		int epfd, int op, unsigned int vec, void *data)
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 37d29643a5..ea38ec183d 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -76,6 +76,8 @@  struct lcore_config lcore_config[RTE_MAX_LCORE];
 /* used by rte_rdtsc() */
 int rte_cycles_vmware_tsc_map;
 
+/* used to judge if is forked */
+static int is_forked;
 
 int
 eal_clean_runtime_dir(void)
@@ -954,6 +956,11 @@  eal_worker_thread_create(unsigned int lcore_id)
 	return ret;
 }
 
+static void mark_forked(void)
+{
+	is_forked++;
+}
+
 /* Launch threads, called at application init(). */
 int
 rte_eal_init(int argc, char **argv)
@@ -1324,6 +1331,8 @@  rte_eal_init(int argc, char **argv)
 
 	eal_mcfg_complete();
 
+	pthread_atfork(NULL, NULL, mark_forked);
+
 	return fctret;
 }
 
@@ -1347,6 +1356,9 @@  mark_freeable(const struct rte_memseg_list *msl, const struct rte_memseg *ms,
 int
 rte_eal_cleanup(void)
 {
+	if (is_forked)
+		return 0;
+
 	/* if we're in a primary process, we need to mark hugepages as freeable
 	 * so that finalization can release them back to the system.
 	 */
@@ -1362,6 +1374,7 @@  rte_eal_cleanup(void)
 	vfio_mp_sync_cleanup();
 #endif
 	rte_mp_channel_cleanup();
+	rte_eal_intr_destroy();
 	rte_trace_save();
 	eal_trace_fini();
 	/* after this point, any DPDK pointers will become dangling */
diff --git a/lib/eal/linux/eal_interrupts.c b/lib/eal/linux/eal_interrupts.c
index d52ec8eb4c..7e9853e8e7 100644
--- a/lib/eal/linux/eal_interrupts.c
+++ b/lib/eal/linux/eal_interrupts.c
@@ -1199,6 +1199,18 @@  rte_eal_intr_init(void)
 	return ret;
 }
 
+void
+rte_eal_intr_destroy(void)
+{
+	/* cancel the host thread to wait/handle the interrupt */
+	pthread_cancel(intr_thread);
+	pthread_join(intr_thread, NULL);
+
+	/* close the pipe used by epoll */
+	close(intr_pipe.writefd);
+	close(intr_pipe.readfd);
+}
+
 static void
 eal_intr_proc_rxtx_intr(int fd, const struct rte_intr_handle *intr_handle)
 {