X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fcompat%2Fcompat-epoll.c;h=29bd2f868ed38e1e6253b8841f2326025cb8c644;hb=6c1c0768320135c6936c371b09731851b508c023;hp=f014a0d783d434f57fc95a5c17e126f62946e74e;hpb=94cc2fd1d4c93bf52c9142999ad0355ad7bc7323;p=lttng-tools.git

diff --git a/src/common/compat/compat-epoll.c b/src/common/compat/compat-epoll.c
index f014a0d78..29bd2f868 100644
--- a/src/common/compat/compat-epoll.c
+++ b/src/common/compat/compat-epoll.c
@@ -16,6 +16,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <fcntl.h>
 #include <limits.h>
@@ -27,6 +28,8 @@
 
 #include <common/error.h>
 #include <common/defaults.h>
+#include <common/macros.h>
+#include <common/utils.h>
 
 #include "poll.h"
 
@@ -49,6 +52,11 @@ static int resize_poll_event(struct lttng_poll_event *events,
 		PERROR("realloc epoll add");
 		goto error;
 	}
+	if (new_size > events->alloc_size) {
+		/* Zero newly allocated memory */
+		memset(ptr + events->alloc_size, 0,
+			(new_size - events->alloc_size) * sizeof(*ptr));
+	}
 	events->events = ptr;
 	events->alloc_size = new_size;
 
@@ -74,7 +82,7 @@ int compat_epoll_create(struct lttng_poll_event *events, int size, int flags)
 		size = poll_max_size;
 	}
 
-	ret = epoll_create1(flags);
+	ret = compat_glibc_epoll_create(size, flags);
 	if (ret < 0) {
 		/* At this point, every error is fatal */
 		PERROR("epoll_create1");
@@ -117,6 +125,11 @@ int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_event
 		goto error;
 	}
 
+	/*
+	 * Zero struct epoll_event to ensure all representations of its
+	 * union are zeroed.
+	 */
+	memset(&ev, 0, sizeof(ev));
 	ev.events = req_events;
 	ev.data.fd = fd;
 
@@ -201,11 +214,15 @@ int compat_epoll_wait(struct lttng_poll_event *events, int timeout)
 	 */
 	if (events->nb_fd > events->alloc_size) {
 		/* Expand if the nb_fd is higher than the actual size. */
-		new_size = events->alloc_size << 1UL;
+		new_size = max_t(uint32_t,
+				1U << utils_get_count_order_u32(events->nb_fd),
+				events->alloc_size << 1UL);
 	} else if ((events->nb_fd << 1UL) <= events->alloc_size &&
 			events->nb_fd >= events->init_size) {
 		/* Shrink if nb_fd multiplied by two is <= than the actual size. */
-		new_size = events->alloc_size >> 1UL;
+		new_size = max_t(uint32_t,
+				utils_get_count_order_u32(events->nb_fd) >> 1U,
+				events->alloc_size >> 1U);
 	} else {
 		/* Indicate that we don't want to resize. */
 		new_size = 0;
@@ -244,6 +261,7 @@ error:
 void compat_epoll_set_max_size(void)
 {
 	int ret, fd;
+	ssize_t size_ret;
 	char buf[64];
 
 	poll_max_size = DEFAULT_POLL_SIZE;
@@ -253,11 +271,16 @@ void compat_epoll_set_max_size(void)
 		return;
 	}
 
-	ret = read(fd, buf, sizeof(buf));
-	if (ret < 0) {
+	size_ret = lttng_read(fd, buf, sizeof(buf));
+	/*
+	 * Allow reading a file smaller than buf, but keep space for
+	 * final \0.
+	 */
+	if (size_ret < 0 || size_ret >= sizeof(buf)) {
 		PERROR("read set max size");
 		goto error;
 	}
+	buf[size_ret] = '\0';
 
 	poll_max_size = atoi(buf);
 	if (poll_max_size == 0) {