[LTP] [PATCH v2 1/2] syscalls/epoll_*: allow for epoll_wait returning a subset of events

[LTP] [PATCH v2 1/2] syscalls/epoll_*: allow for epoll_wait returning a subset of events

[Steve Muckle]

The epoll_wait syscall is not guaranteed to return all pending events -
a subset may be returned. Modify the epoll_wait01 and epoll_ctl01
testcases to allow for that.

CC: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Steve Muckle <smuckle.linux@gmail.com>
---
 testcases/kernel/syscalls/epoll_ctl/epoll_ctl01.c  | 52 ++++++++++----------
 .../kernel/syscalls/epoll_wait/epoll_wait01.c      | 55 ++++++++++++----------
 2 files changed, 57 insertions(+), 50 deletions(-)

diff --git a/testcases/kernel/syscalls/epoll_ctl/epoll_ctl01.c b/testcases/kernel/syscalls/epoll_ctl/epoll_ctl01.c
index 0fa1ab25f..f3599de50 100644
--- a/testcases/kernel/syscalls/epoll_ctl/epoll_ctl01.c
+++ b/testcases/kernel/syscalls/epoll_ctl/epoll_ctl01.c
@@ -85,41 +85,43 @@ static int has_event(struct epoll_event *epvs, int len,
 static void check_epoll_ctl(int opt, int exp_num)
 {
 	int res;
-
+	unsigned int events;
 	char write_buf[] = "test";
 	char read_buf[sizeof(write_buf)];
+	struct epoll_event res_evs[2];
 
-	struct epoll_event res_evs[2] = {
-		{.events = 0, .data.fd = 0},
-		{.events = 0, .data.fd = 0}
-	};
+	events = EPOLLIN;
+	if (exp_num == 2)
+		events |= EPOLLOUT;
 
 	SAFE_WRITE(1, fd[1], write_buf, sizeof(write_buf));
 
-	res = epoll_wait(epfd, res_evs, 2, -1);
-	if (res == -1)
-		tst_brk(TBROK | TERRNO, "epoll_wait() fails");
-
-	if (res != exp_num) {
-		tst_res(TFAIL, "epoll_wait() returns %i, expected %i",
-			res, exp_num);
-		goto end;
-	}
+	while (events) {
+		int events_matched = 0;
+		bzero(res_evs, sizeof(res_evs));
 
-	if (exp_num == 1) {
-		if (!has_event(res_evs, 2, fd[0], EPOLLIN) ||
-		    !has_event(res_evs, 2, 0, 0)) {
-			tst_res(TFAIL, "epoll_wait() fails to "
-				"get expected fd and event");
+		res = epoll_wait(epfd, res_evs, 2, -1);
+		if (res <= 0) {
+			tst_res(TFAIL | TERRNO, "epoll_wait() returned %i",
+				res);
 			goto end;
 		}
-	}
 
-	if (exp_num == 2) {
-		if (!has_event(res_evs, 2, fd[0], EPOLLIN) ||
-		    !has_event(res_evs, 2, fd[1], EPOLLOUT)) {
-			tst_res(TFAIL, "epoll_wait() fails to "
-				"get expected fd and event");
+		if ((events & EPOLLIN) &&
+		    has_event(res_evs, 2, fd[0], EPOLLIN)) {
+			events_matched++;
+			events &= ~EPOLLIN;
+		}
+
+		if ((events & EPOLLOUT) &&
+		    has_event(res_evs, 2, fd[1], EPOLLOUT)) {
+			events_matched++;
+			events &= ~EPOLLOUT;
+		}
+
+		if (res != events_matched) {
+			tst_res(TFAIL,
+				"epoll_wait() returned unexpected events");
 			goto end;
 		}
 	}
diff --git a/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c b/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
index c8c55720f..10f8b6ca6 100644
--- a/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
+++ b/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
@@ -200,34 +200,39 @@ static void verify_epollio(void)
 {
 	char write_buf[] = "Testing";
 	char read_buf[sizeof(write_buf)];
+	uint32_t events = EPOLLIN | EPOLLOUT;
 
 	SAFE_WRITE(cleanup, 1, fds[1], write_buf, sizeof(write_buf));
 
-	TEST(epoll_wait(epfd, epevs, 3, -1));
-
-	if (TEST_RETURN == -1) {
-		tst_resm(TFAIL | TTERRNO, "epoll_wait() epollio failed");
-		goto end;
-	}
-
-	if (TEST_RETURN != 2) {
-		tst_resm(TFAIL, "epoll_wait() returned %li, expected 2",
-			 TEST_RETURN);
-		goto end;
-	}
-
-	if (!has_event(epevs, 2, fds[0], EPOLLIN)) {
-		dump_epevs(epevs, 2);
-		tst_resm(TFAIL, "epoll_wait() expected %d and EPOLLIN %x",
-			 fds[0], EPOLLIN);
-		goto end;
-	}
-
-	if (!has_event(epevs, 2, fds[1], EPOLLOUT)) {
-		dump_epevs(epevs, 2);
-		tst_resm(TFAIL, "epoll_wait() expected %d and EPOLLOUT %x",
-			 fds[1], EPOLLOUT);
-		goto end;
+	while (events) {
+		int events_matched = 0;
+
+		TEST(epoll_wait(epfd, epevs, 3, -1));
+
+		if (TEST_RETURN <= 0) {
+			tst_resm(TFAIL | TTERRNO, "epoll_wait() returned %i",
+				 TEST_RETURN);
+			goto end;
+		}
+
+		if ((events & EPOLLIN) &&
+		    has_event(epevs, 2, fds[0], EPOLLIN)) {
+			events_matched++;
+			events &= ~EPOLLIN;
+		}
+
+		if ((events & EPOLLOUT) &&
+		    has_event(epevs, 2, fds[1], EPOLLOUT)) {
+			events_matched++;
+			events &= ~EPOLLOUT;
+		}
+
+		if (TEST_RETURN != events_matched) {
+			tst_resm(TFAIL,
+				 "epoll_wait() returned unexpected events");
+			dump_epevs(epevs, 2);
+			goto end;
+		}
 	}
 
 	tst_resm(TPASS, "epoll_wait() epollio");
-- 
2.14.0.rc0.400.g1c36432dff-goog

[LTP] [PATCH v2 2/2] syscalls/epoll_wait01: cleanup data structure usage

[Steve Muckle]

The fds2 data structure is not used during the test, remove it.
Ensure the event structure that epoll_wait() writes into is cleared
prior to invoking the call so that the returned data is confidently
known.

Signed-off-by: Steve Muckle <smuckle.linux@gmail.com>
---
 .../kernel/syscalls/epoll_wait/epoll_wait01.c      | 49 ++++++++++------------
 1 file changed, 22 insertions(+), 27 deletions(-)

diff --git a/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c b/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
index 10f8b6ca6..9afd2dae2 100644
--- a/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
+++ b/testcases/kernel/syscalls/epoll_wait/epoll_wait01.c
@@ -34,11 +34,10 @@
 char *TCID = "epoll_wait01";
 int TST_TOTAL = 3;
 
-static int write_size, epfd, fds[2], fds2[2];
-static struct epoll_event epevs[3] = {
+static int write_size, epfd, fds[2];
+static struct epoll_event epevs[2] = {
 	{.events = EPOLLIN},
 	{.events = EPOLLOUT},
-	{.events = EPOLLIN}
 };
 
 static void setup(void);
@@ -77,7 +76,6 @@ static void setup(void)
 	TEST_PAUSE;
 
 	SAFE_PIPE(NULL, fds);
-	SAFE_PIPE(cleanup, fds2);
 
 	write_size = get_writesize();
 
@@ -89,11 +87,9 @@ static void setup(void)
 
 	epevs[0].data.fd = fds[0];
 	epevs[1].data.fd = fds[1];
-	epevs[2].data.fd = fds2[0];
 
 	if (epoll_ctl(epfd, EPOLL_CTL_ADD, fds[0], &epevs[0]) ||
-	    epoll_ctl(epfd, EPOLL_CTL_ADD, fds[1], &epevs[1]) ||
-	    epoll_ctl(epfd, EPOLL_CTL_ADD, fds2[0], &epevs[2])) {
+	    epoll_ctl(epfd, EPOLL_CTL_ADD, fds[1], &epevs[1])) {
 		tst_brkm(TBROK | TERRNO, cleanup,
 			 "failed to register epoll target");
 	}
@@ -128,7 +124,9 @@ static int get_writesize(void)
 
 static void verify_epollout(void)
 {
-	TEST(epoll_wait(epfd, epevs, 3, -1));
+	struct epoll_event ret_evs = {.events = 0, .data.fd = 0};
+
+	TEST(epoll_wait(epfd, &ret_evs, 1, -1));
 
 	if (TEST_RETURN == -1) {
 		tst_resm(TFAIL | TTERRNO, "epoll_wait() epollout failed");
@@ -141,15 +139,15 @@ static void verify_epollout(void)
 		return;
 	}
 
-	if (epevs[0].data.fd != fds[1]) {
+	if (ret_evs.data.fd != fds[1]) {
 		tst_resm(TFAIL, "epoll.data.fd %i, expected %i",
-			 epevs[0].data.fd, fds[1]);
+			 ret_evs.data.fd, fds[1]);
 		return;
 	}
 
-	if (epevs[0].events != EPOLLOUT) {
+	if (ret_evs.events != EPOLLOUT) {
 		tst_resm(TFAIL, "epoll.events %x, expected EPOLLOUT %x",
-			 epevs[0].events, EPOLLOUT);
+			 ret_evs.events, EPOLLOUT);
 		return;
 	}
 
@@ -160,12 +158,13 @@ static void verify_epollin(void)
 {
 	char write_buf[write_size];
 	char read_buf[sizeof(write_buf)];
+	struct epoll_event ret_evs = {.events = 0, .data.fd = 0};
 
 	memset(write_buf, 'a', sizeof(write_buf));
 
 	SAFE_WRITE(cleanup, 1, fds[1], write_buf, sizeof(write_buf));
 
-	TEST(epoll_wait(epfd, epevs, 3, -1));
+	TEST(epoll_wait(epfd, &ret_evs, 1, -1));
 
 	if (TEST_RETURN == -1) {
 		tst_resm(TFAIL | TTERRNO, "epoll_wait() epollin failed");
@@ -178,15 +177,15 @@ static void verify_epollin(void)
 		goto end;
 	}
 
-	if (epevs[0].data.fd != fds[0]) {
+	if (ret_evs.data.fd != fds[0]) {
 		tst_resm(TFAIL, "epoll.data.fd %i, expected %i",
-			 epevs[0].data.fd, fds[0]);
+			 ret_evs.data.fd, fds[0]);
 		goto end;
 	}
 
-	if (epevs[0].events != EPOLLIN) {
+	if (ret_evs.events != EPOLLIN) {
 		tst_resm(TFAIL, "epoll.events %x, expected EPOLLIN %x",
-			 epevs[0].events, EPOLLIN);
+			 ret_evs.events, EPOLLIN);
 		goto end;
 	}
 
@@ -201,13 +200,15 @@ static void verify_epollio(void)
 	char write_buf[] = "Testing";
 	char read_buf[sizeof(write_buf)];
 	uint32_t events = EPOLLIN | EPOLLOUT;
+	struct epoll_event ret_evs[2];
 
 	SAFE_WRITE(cleanup, 1, fds[1], write_buf, sizeof(write_buf));
 
 	while (events) {
 		int events_matched = 0;
 
-		TEST(epoll_wait(epfd, epevs, 3, -1));
+		bzero(ret_evs, sizeof(ret_evs));
+		TEST(epoll_wait(epfd, ret_evs, 2, -1));
 
 		if (TEST_RETURN <= 0) {
 			tst_resm(TFAIL | TTERRNO, "epoll_wait() returned %i",
@@ -216,13 +217,13 @@ static void verify_epollio(void)
 		}
 
 		if ((events & EPOLLIN) &&
-		    has_event(epevs, 2, fds[0], EPOLLIN)) {
+		    has_event(ret_evs, 2, fds[0], EPOLLIN)) {
 			events_matched++;
 			events &= ~EPOLLIN;
 		}
 
 		if ((events & EPOLLOUT) &&
-		    has_event(epevs, 2, fds[1], EPOLLOUT)) {
+		    has_event(ret_evs, 2, fds[1], EPOLLOUT)) {
 			events_matched++;
 			events &= ~EPOLLOUT;
 		}
@@ -230,7 +231,7 @@ static void verify_epollio(void)
 		if (TEST_RETURN != events_matched) {
 			tst_resm(TFAIL,
 				 "epoll_wait() returned unexpected events");
-			dump_epevs(epevs, 2);
+			dump_epevs(ret_evs, 2);
 			goto end;
 		}
 	}
@@ -274,10 +275,4 @@ static void cleanup(void)
 
 	if (close(fds[1]))
 		tst_resm(TWARN | TERRNO, "failed to close fds[1]");
-
-	if (fds2[0] > 0 && close(fds2[0]))
-		tst_resm(TWARN | TERRNO, "failed to close fds2[0]");
-
-	if (fds2[1] > 0 && close(fds2[1]))
-		tst_resm(TWARN | TERRNO, "failed to close fds2[1]");
 }
-- 
2.14.0.rc0.400.g1c36432dff-goog

[LTP] [PATCH v2 2/2] syscalls/epoll_wait01: cleanup data structure usage

[Cyril Hrubis]

Hi!
>  		if (TEST_RETURN <= 0) {
>  			tst_resm(TFAIL | TTERRNO, "epoll_wait() returned %i",
                                                                          ^
							The TEST_RETURN
							is long hence
							this has to be
							%li

I've ammended this changed to this patch and pushed both, thanks.

-- 
Cyril Hrubis
chrubis@suse.cz