[PATCH v3 1/5] build: Add sanitizer options

[PATCH v3 1/5] build: Add sanitizer options

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 3585 bytes --]

Build using Address Sanitizer (asan), Leak Sanitizer (lsan), or
Undefined Behavior Sanitizer (ubsan) by using one of these options for
the configure script:

  --enable-asan
  --enable-lsan
  --enable-ubsan

For each of these to work, the compiler must support the requested
sanitizer and the requisite libraries must be installed (libasan,
liblsan, libubsan).
---
 acinclude.m4 | 36 ++++++++++++++++++++++++++++++++++++
 configure.ac | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/acinclude.m4 b/acinclude.m4
index 0ba4287..8aab4ee 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -10,6 +10,42 @@ AC_DEFUN([AC_PROG_CC_PIE], [
 	])
 ])
 
+AC_DEFUN([AC_PROG_CC_ASAN], [
+	AC_CACHE_CHECK([whether ${CC-cc} accepts -fsanitize=address], ac_cv_prog_cc_asan, [
+		echo 'void f(){}' > conftest.c
+		if test -z "`${CC-cc} -fsanitize=address -c conftest.c 2>&1`"; then
+			ac_cv_prog_cc_asan=yes
+		else
+			ac_cv_prog_cc_asan=no
+		fi
+		rm -rf conftest*
+	])
+])
+
+AC_DEFUN([AC_PROG_CC_LSAN], [
+	AC_CACHE_CHECK([whether ${CC-cc} accepts -fsanitize=leak], ac_cv_prog_cc_lsan, [
+		echo 'void f(){}' > conftest.c
+		if test -z "`${CC-cc} -fsanitize=leak -c conftest.c 2>&1`"; then
+			ac_cv_prog_cc_lsan=yes
+		else
+			ac_cv_prog_cc_lsan=no
+		fi
+		rm -rf conftest*
+	])
+])
+
+AC_DEFUN([AC_PROG_CC_UBSAN], [
+	AC_CACHE_CHECK([whether ${CC-cc} accepts -fsanitize=undefined], ac_cv_prog_cc_ubsan, [
+		echo 'void f(){}' > conftest.c
+		if test -z "`${CC-cc} -fsanitize=undefined -c conftest.c 2>&1`"; then
+			ac_cv_prog_cc_ubsan=yes
+		else
+			ac_cv_prog_cc_ubsan=no
+		fi
+		rm -rf conftest*
+	])
+])
+
 AC_DEFUN([COMPILER_FLAGS], [
 	if (test "${CFLAGS}" = ""); then
 		CFLAGS="-Wall -O2 -fsigned-char"
diff --git a/configure.ac b/configure.ac
index 39755fe..e4ca5b2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,6 +20,9 @@ AC_LANG_C
 
 AC_PROG_CC
 AC_PROG_CC_PIE
+AC_PROG_CC_ASAN
+AC_PROG_CC_LSAN
+AC_PROG_CC_UBSAN
 AC_PROG_INSTALL
 
 AC_C_CHAR_UNSIGNED
@@ -54,6 +57,48 @@ AC_ARG_ENABLE(pie, AC_HELP_STRING([--enable-pie],
 	fi
 ])
 
+save_LIBS=$LIBS
+AC_CHECK_LIB(asan, __sanitizer_cov_init)
+LIBS=$save_LIBS
+
+AC_ARG_ENABLE(asan, AC_HELP_STRING([--enable-asan],
+			[enable linking with address sanitizer]), [
+	if (test "${enableval}" = "yes" &&
+				test "${ac_cv_lib_asan___sanitizer_cov_init}" = "yes" &&
+				test "${ac_cv_prog_cc_asan}" = "yes"); then
+		CFLAGS="$CFLAGS -fsanitize=address";
+		LDFLAGS="$LDFLAGS -fsanitize=address"
+	fi
+])
+
+save_LIBS=$LIBS
+AC_CHECK_LIB(lsan, __sanitizer_cov_init)
+LIBS=$save_LIBS
+
+AC_ARG_ENABLE(lsan, AC_HELP_STRING([--enable-lsan],
+			[enable linking with leak sanitizer]), [
+	if (test "${enableval}" = "yes" &&
+				test "${ac_cv_lib_lsan___sanitizer_cov_init}" = "yes" &&
+				test "${ac_cv_prog_cc_lsan}" = "yes"); then
+		CFLAGS="$CFLAGS -fsanitize=leak";
+		LDFLAGS="$LDFLAGS -fsanitize=leak"
+	fi
+])
+
+save_LIBS=$LIBS
+AC_CHECK_LIB(ubsan, __sanitizer_cov_init)
+LIBS=$save_LIBS
+
+AC_ARG_ENABLE(ubsan, AC_HELP_STRING([--enable-ubsan],
+			[enable linking with undefined behavior sanitizer]), [
+	if (test "${enableval}" = "yes" &&
+				test "${ac_cv_lib_ubsan___sanitizer_cov_init}" = "yes" &&
+				test "${ac_cv_prog_cc_ubsan}" = "yes"); then
+		CFLAGS="$CFLAGS -fsanitize=undefined";
+		LDFLAGS="$LDFLAGS -fsanitize=undefined"
+	fi
+])
+
 AC_CHECK_FUNC(signalfd, dummy=yes,
 			AC_MSG_ERROR(signalfd support is required))
 
-- 
2.7.3

[PATCH v3 2/5] unit: Add race condition test to test-main

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 2482 bytes --]

This test excercises the case where multiple events are returned from
the same epoll_wait call and an early event deletes a watch that is
waiting to be processed in the same event loop iteration.
---
 unit/test-main.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/unit/test-main.c b/unit/test-main.c
index b61e337..469d186 100644
--- a/unit/test-main.c
+++ b/unit/test-main.c
@@ -25,6 +25,7 @@
 #endif
 
 #include <ell/ell.h>
+#include <unistd.h>
 
 static void signal_handler(struct l_signal *signal, uint32_t signo,
 							void *user_data)
@@ -38,7 +39,7 @@ static void signal_handler(struct l_signal *signal, uint32_t signo,
 	}
 }
 
-static void timeout_handler(struct l_timeout *timeout, void *user_data)
+static void timeout_quit_handler(struct l_timeout *timeout, void *user_data)
 {
 	l_main_quit();
 }
@@ -58,9 +59,27 @@ static void oneshot_handler(void *user_data)
 	l_info("One-shot");
 }
 
+static void race_delay_handler(struct l_timeout *timeout, void *user_data)
+{
+	l_info("Delay");
+	usleep(250 * 1000);
+}
+
+static void race_handler(struct l_timeout *timeout, void *user_data)
+{
+	struct l_timeout **other_racer = user_data;
+
+	l_info("Remove pending event");
+	l_timeout_remove(*other_racer);
+	*other_racer = NULL;
+}
+
 int main(int argc, char *argv[])
 {
-	struct l_timeout *timeout;
+	struct l_timeout *timeout_quit;
+	struct l_timeout *race_delay;
+	struct l_timeout *race1;
+	struct l_timeout *race2;
 	struct l_signal *signal;
 	struct l_idle *idle;
 	sigset_t mask;
@@ -71,7 +90,13 @@ int main(int argc, char *argv[])
 
 	signal = l_signal_create(&mask, signal_handler, NULL, NULL);
 
-	timeout = l_timeout_create(3, timeout_handler, NULL, NULL);
+	timeout_quit = l_timeout_create(3, timeout_quit_handler, NULL, NULL);
+
+	race_delay = l_timeout_create(1, race_delay_handler, NULL, NULL);
+	race1 = l_timeout_create_with_nanoseconds(1, 100000000, race_handler,
+						  &race2, NULL);
+	race2 = l_timeout_create_with_nanoseconds(1, 100000000, race_handler,
+						  &race1, NULL);
 
 	idle = l_idle_create(idle_handler, NULL, NULL);
 
@@ -85,7 +110,11 @@ int main(int argc, char *argv[])
 
 	l_main_run();
 
-	l_timeout_remove(timeout);
+	l_timeout_remove(race_delay);
+	l_timeout_remove(race1);
+	l_timeout_remove(race2);
+
+	l_timeout_remove(timeout_quit);
 
 	l_signal_remove(signal);
 
-- 
2.7.3

[PATCH v3 3/5] main: Safely free watch_data structures

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 2677 bytes --]

The race condition test in test-main exposed a case where the events
array returned by epoll_wait could have a stale watch_data
pointer. This triggered a use-after-free error that was reported by
the address sanitizer (./configure --enable-asan).

When the event loop is running, watch_data structures with events
being dispatched are flagged. If watch_remove is called on a flagged
structure, the l_free() is deferred until after all events are
dispatched and the callback for that event is skipped.
---
 ell/main.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/ell/main.c b/ell/main.c
index f8fa4ac..6143a42 100644
--- a/ell/main.c
+++ b/ell/main.c
@@ -49,6 +49,9 @@
 #define IDLE_FLAG_DISPATCHING	1
 #define IDLE_FLAG_DESTROYED	2
 
+#define WATCH_FLAG_DISPATCHING	1
+#define WATCH_FLAG_DESTROYED	2
+
 static int epoll_fd;
 static bool epoll_running;
 static bool epoll_terminate;
@@ -60,6 +63,7 @@ static struct l_queue *idle_list;
 struct watch_data {
 	int fd;
 	uint32_t events;
+	uint32_t flags;
 	watch_event_cb_t callback;
 	watch_destroy_cb_t destroy;
 	void *user_data;
@@ -139,6 +143,7 @@ int watch_add(int fd, uint32_t events, watch_event_cb_t callback,
 
 	data->fd = fd;
 	data->events = events;
+	data->flags = 0;
 	data->callback = callback;
 	data->destroy = destroy;
 	data->user_data = user_data;
@@ -212,7 +217,10 @@ int watch_remove(int fd)
 	if (data->destroy)
 		data->destroy(data->user_data);
 
-	l_free(data);
+	if (data->flags & WATCH_FLAG_DISPATCHING)
+		data->flags |= WATCH_FLAG_DESTROYED;
+	else
+		l_free(data);
 
 	return err;
 }
@@ -334,6 +342,7 @@ LIB_EXPORT int l_main_run(void)
 
 	for (;;) {
 		struct epoll_event events[MAX_EPOLL_EVENTS];
+		struct watch_data *data;
 		int n, nfds;
 		int timeout;
 
@@ -344,12 +353,30 @@ LIB_EXPORT int l_main_run(void)
 		nfds = epoll_wait(epoll_fd, events, MAX_EPOLL_EVENTS, timeout);
 
 		for (n = 0; n < nfds; n++) {
-			struct watch_data *data = events[n].data.ptr;
+			data = events[n].data.ptr;
+
+			data->flags |= WATCH_FLAG_DISPATCHING;
+		}
+
+		for (n = 0; n < nfds; n++) {
+			data = events[n].data.ptr;
+
+			if (data->flags & WATCH_FLAG_DESTROYED)
+				continue;
 
 			data->callback(data->fd, events[n].events,
 							data->user_data);
 		}
 
+		for (n = 0; n < nfds; n++) {
+			data = events[n].data.ptr;
+
+			if (data->flags & WATCH_FLAG_DESTROYED)
+				l_free(data);
+			else
+				data->flags = 0;
+		}
+
 		l_queue_foreach(idle_list, idle_dispatch, NULL);
 		l_queue_foreach_remove(idle_list, idle_prune, NULL);
 	}
-- 
2.7.3

[PATCH v3 4/5] main: Remove unnecessary error check

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 714 bytes --]

l_queue_new() cannot fail, so there's no need to check for NULL or do
other cleanup.
---
 ell/main.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/ell/main.c b/ell/main.c
index 6143a42..46e929a 100644
--- a/ell/main.c
+++ b/ell/main.c
@@ -100,8 +100,6 @@ static inline bool __attribute__ ((always_inline)) create_epoll(void)
 		goto close_epoll;
 
 	idle_list = l_queue_new();
-	if (!idle_list)
-		goto free_watch_list;
 
 	idle_id = 0;
 
@@ -112,10 +110,6 @@ static inline bool __attribute__ ((always_inline)) create_epoll(void)
 
 	return true;
 
-free_watch_list:
-	free(watch_list);
-	watch_list = NULL;
-
 close_epoll:
 	close(epoll_fd);
 	epoll_fd = 0;
-- 
2.7.3

[PATCH v3 5/5] unit: Add test-main check for self-removal

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 1126 bytes --]

Call l_timeout_remove() within a handler for the same timeout.
---
 unit/test-main.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/unit/test-main.c b/unit/test-main.c
index 469d186..ee99a4b 100644
--- a/unit/test-main.c
+++ b/unit/test-main.c
@@ -74,12 +74,19 @@ static void race_handler(struct l_timeout *timeout, void *user_data)
 	*other_racer = NULL;
 }
 
+static void remove_handler(struct l_timeout *timeout, void *user_data)
+{
+	l_timeout_remove(timeout);
+	l_info("Timer removed itself");
+}
+
 int main(int argc, char *argv[])
 {
 	struct l_timeout *timeout_quit;
 	struct l_timeout *race_delay;
 	struct l_timeout *race1;
 	struct l_timeout *race2;
+	struct l_timeout *remove_self;
 	struct l_signal *signal;
 	struct l_idle *idle;
 	sigset_t mask;
@@ -98,6 +105,8 @@ int main(int argc, char *argv[])
 	race2 = l_timeout_create_with_nanoseconds(1, 100000000, race_handler,
 						  &race1, NULL);
 
+	remove_self = l_timeout_create(2, remove_handler, &remove_self, NULL);
+
 	idle = l_idle_create(idle_handler, NULL, NULL);
 
 	l_log_set_stderr();
-- 
2.7.3

Re: [PATCH v3 2/5] unit: Add race condition test to test-main

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 323 bytes --]


On Thu, 17 Mar 2016, Mat Martineau wrote:

> This test excercises the case where multiple events are returned from

Oops, should be "exercises"

> the same epoll_wait call and an early event deletes a watch that is
> waiting to be processed in the same event loop iteration.


--
Mat Martineau
Intel OTC

[PATCH v4 2/5] unit: Add race condition test to test-main

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 2481 bytes --]

This test exercises the case where multiple events are returned from
the same epoll_wait call and an early event deletes a watch that is
waiting to be processed in the same event loop iteration.
---
 unit/test-main.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/unit/test-main.c b/unit/test-main.c
index b61e337..469d186 100644
--- a/unit/test-main.c
+++ b/unit/test-main.c
@@ -25,6 +25,7 @@
 #endif
 
 #include <ell/ell.h>
+#include <unistd.h>
 
 static void signal_handler(struct l_signal *signal, uint32_t signo,
 							void *user_data)
@@ -38,7 +39,7 @@ static void signal_handler(struct l_signal *signal, uint32_t signo,
 	}
 }
 
-static void timeout_handler(struct l_timeout *timeout, void *user_data)
+static void timeout_quit_handler(struct l_timeout *timeout, void *user_data)
 {
 	l_main_quit();
 }
@@ -58,9 +59,27 @@ static void oneshot_handler(void *user_data)
 	l_info("One-shot");
 }
 
+static void race_delay_handler(struct l_timeout *timeout, void *user_data)
+{
+	l_info("Delay");
+	usleep(250 * 1000);
+}
+
+static void race_handler(struct l_timeout *timeout, void *user_data)
+{
+	struct l_timeout **other_racer = user_data;
+
+	l_info("Remove pending event");
+	l_timeout_remove(*other_racer);
+	*other_racer = NULL;
+}
+
 int main(int argc, char *argv[])
 {
-	struct l_timeout *timeout;
+	struct l_timeout *timeout_quit;
+	struct l_timeout *race_delay;
+	struct l_timeout *race1;
+	struct l_timeout *race2;
 	struct l_signal *signal;
 	struct l_idle *idle;
 	sigset_t mask;
@@ -71,7 +90,13 @@ int main(int argc, char *argv[])
 
 	signal = l_signal_create(&mask, signal_handler, NULL, NULL);
 
-	timeout = l_timeout_create(3, timeout_handler, NULL, NULL);
+	timeout_quit = l_timeout_create(3, timeout_quit_handler, NULL, NULL);
+
+	race_delay = l_timeout_create(1, race_delay_handler, NULL, NULL);
+	race1 = l_timeout_create_with_nanoseconds(1, 100000000, race_handler,
+						  &race2, NULL);
+	race2 = l_timeout_create_with_nanoseconds(1, 100000000, race_handler,
+						  &race1, NULL);
 
 	idle = l_idle_create(idle_handler, NULL, NULL);
 
@@ -85,7 +110,11 @@ int main(int argc, char *argv[])
 
 	l_main_run();
 
-	l_timeout_remove(timeout);
+	l_timeout_remove(race_delay);
+	l_timeout_remove(race1);
+	l_timeout_remove(race2);
+
+	l_timeout_remove(timeout_quit);
 
 	l_signal_remove(signal);
 
-- 
2.7.3

Re: [PATCH v4 2/5] unit: Add race condition test to test-main

[Denis Kenzior]

[-- Attachment #1: Type: text/plain, Size: 429 bytes --]

Hi Mat,

On 03/17/2016 01:19 PM, Mat Martineau wrote:
> This test exercises the case where multiple events are returned from
> the same epoll_wait call and an early event deletes a watch that is
> waiting to be processed in the same event loop iteration.
> ---
>   unit/test-main.c | 37 +++++++++++++++++++++++++++++++++----
>   1 file changed, 33 insertions(+), 4 deletions(-)

Applied, thanks.

Regards,
-Denis

Re: [PATCH v3 3/5] main: Safely free watch_data structures

[Denis Kenzior]

[-- Attachment #1: Type: text/plain, Size: 756 bytes --]

Hi Mat,

On 03/17/2016 01:15 PM, Mat Martineau wrote:
> The race condition test in test-main exposed a case where the events
> array returned by epoll_wait could have a stale watch_data
> pointer. This triggered a use-after-free error that was reported by
> the address sanitizer (./configure --enable-asan).
>
> When the event loop is running, watch_data structures with events
> being dispatched are flagged. If watch_remove is called on a flagged
> structure, the l_free() is deferred until after all events are
> dispatched and the callback for that event is skipped.
> ---
>   ell/main.c | 31 +++++++++++++++++++++++++++++--
>   1 file changed, 29 insertions(+), 2 deletions(-)
>

Patches 3-5 applied.  Thanks.

Regards,
-Denis

Re: [PATCH v3 1/5] build: Add sanitizer options

[Mat Martineau]

[-- Attachment #1: Type: text/plain, Size: 3938 bytes --]


Marcel - any issues with this patch?


On Thu, 17 Mar 2016, Mat Martineau wrote:

> Build using Address Sanitizer (asan), Leak Sanitizer (lsan), or
> Undefined Behavior Sanitizer (ubsan) by using one of these options for
> the configure script:
>
>  --enable-asan
>  --enable-lsan
>  --enable-ubsan
>
> For each of these to work, the compiler must support the requested
> sanitizer and the requisite libraries must be installed (libasan,
> liblsan, libubsan).
> ---
> acinclude.m4 | 36 ++++++++++++++++++++++++++++++++++++
> configure.ac | 45 +++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 81 insertions(+)
>
> diff --git a/acinclude.m4 b/acinclude.m4
> index 0ba4287..8aab4ee 100644
> --- a/acinclude.m4
> +++ b/acinclude.m4
> @@ -10,6 +10,42 @@ AC_DEFUN([AC_PROG_CC_PIE], [
> 	])
> ])
>
> +AC_DEFUN([AC_PROG_CC_ASAN], [
> +	AC_CACHE_CHECK([whether ${CC-cc} accepts -fsanitize=address], ac_cv_prog_cc_asan, [
> +		echo 'void f(){}' > conftest.c
> +		if test -z "`${CC-cc} -fsanitize=address -c conftest.c 2>&1`"; then
> +			ac_cv_prog_cc_asan=yes
> +		else
> +			ac_cv_prog_cc_asan=no
> +		fi
> +		rm -rf conftest*
> +	])
> +])
> +
> +AC_DEFUN([AC_PROG_CC_LSAN], [
> +	AC_CACHE_CHECK([whether ${CC-cc} accepts -fsanitize=leak], ac_cv_prog_cc_lsan, [
> +		echo 'void f(){}' > conftest.c
> +		if test -z "`${CC-cc} -fsanitize=leak -c conftest.c 2>&1`"; then
> +			ac_cv_prog_cc_lsan=yes
> +		else
> +			ac_cv_prog_cc_lsan=no
> +		fi
> +		rm -rf conftest*
> +	])
> +])
> +
> +AC_DEFUN([AC_PROG_CC_UBSAN], [
> +	AC_CACHE_CHECK([whether ${CC-cc} accepts -fsanitize=undefined], ac_cv_prog_cc_ubsan, [
> +		echo 'void f(){}' > conftest.c
> +		if test -z "`${CC-cc} -fsanitize=undefined -c conftest.c 2>&1`"; then
> +			ac_cv_prog_cc_ubsan=yes
> +		else
> +			ac_cv_prog_cc_ubsan=no
> +		fi
> +		rm -rf conftest*
> +	])
> +])
> +
> AC_DEFUN([COMPILER_FLAGS], [
> 	if (test "${CFLAGS}" = ""); then
> 		CFLAGS="-Wall -O2 -fsigned-char"
> diff --git a/configure.ac b/configure.ac
> index 39755fe..e4ca5b2 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -20,6 +20,9 @@ AC_LANG_C
>
> AC_PROG_CC
> AC_PROG_CC_PIE
> +AC_PROG_CC_ASAN
> +AC_PROG_CC_LSAN
> +AC_PROG_CC_UBSAN
> AC_PROG_INSTALL
>
> AC_C_CHAR_UNSIGNED
> @@ -54,6 +57,48 @@ AC_ARG_ENABLE(pie, AC_HELP_STRING([--enable-pie],
> 	fi
> ])
>
> +save_LIBS=$LIBS
> +AC_CHECK_LIB(asan, __sanitizer_cov_init)
> +LIBS=$save_LIBS
> +
> +AC_ARG_ENABLE(asan, AC_HELP_STRING([--enable-asan],
> +			[enable linking with address sanitizer]), [
> +	if (test "${enableval}" = "yes" &&
> +				test "${ac_cv_lib_asan___sanitizer_cov_init}" = "yes" &&
> +				test "${ac_cv_prog_cc_asan}" = "yes"); then
> +		CFLAGS="$CFLAGS -fsanitize=address";
> +		LDFLAGS="$LDFLAGS -fsanitize=address"
> +	fi
> +])
> +
> +save_LIBS=$LIBS
> +AC_CHECK_LIB(lsan, __sanitizer_cov_init)
> +LIBS=$save_LIBS
> +
> +AC_ARG_ENABLE(lsan, AC_HELP_STRING([--enable-lsan],
> +			[enable linking with leak sanitizer]), [
> +	if (test "${enableval}" = "yes" &&
> +				test "${ac_cv_lib_lsan___sanitizer_cov_init}" = "yes" &&
> +				test "${ac_cv_prog_cc_lsan}" = "yes"); then
> +		CFLAGS="$CFLAGS -fsanitize=leak";
> +		LDFLAGS="$LDFLAGS -fsanitize=leak"
> +	fi
> +])
> +
> +save_LIBS=$LIBS
> +AC_CHECK_LIB(ubsan, __sanitizer_cov_init)
> +LIBS=$save_LIBS
> +
> +AC_ARG_ENABLE(ubsan, AC_HELP_STRING([--enable-ubsan],
> +			[enable linking with undefined behavior sanitizer]), [
> +	if (test "${enableval}" = "yes" &&
> +				test "${ac_cv_lib_ubsan___sanitizer_cov_init}" = "yes" &&
> +				test "${ac_cv_prog_cc_ubsan}" = "yes"); then
> +		CFLAGS="$CFLAGS -fsanitize=undefined";
> +		LDFLAGS="$LDFLAGS -fsanitize=undefined"
> +	fi
> +])
> +
> AC_CHECK_FUNC(signalfd, dummy=yes,
> 			AC_MSG_ERROR(signalfd support is required))
>
> -- 
> 2.7.3
>
>


--
Mat Martineau
Intel OTC