From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri, 21 Feb 2014 16:01:01 +0000 (-0500)
Subject: Fix: handle sysconf errors
X-Git-Tag: v2.4.0~16
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=172d6b687981b2606a5ad9caffba5686be96ff28;p=lttng-ust.git

Fix: handle sysconf errors

CID 1021261 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)10.
negative_returns: "sysconf(30)" is passed to a parameter that cannot be
negative.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 74d805ae..77cde295 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -819,9 +819,14 @@ void cleanup_sock_info(struct sock_info *sock_info, int exiting)
 		sock_info->notify_socket = -1;
 	}
 	if (sock_info->wait_shm_mmap) {
-		ret = munmap(sock_info->wait_shm_mmap, sysconf(_SC_PAGE_SIZE));
-		if (ret) {
-			ERR("Error unmapping wait shm");
+		long page_size;
+
+		page_size = sysconf(_SC_PAGE_SIZE);
+		if (page_size > 0) {
+			ret = munmap(sock_info->wait_shm_mmap, page_size);
+			if (ret) {
+				ERR("Error unmapping wait shm");
+			}
 		}
 		sock_info->wait_shm_mmap = NULL;
 	}
@@ -994,15 +999,20 @@ error_close:
 static
 char *get_map_shm(struct sock_info *sock_info)
 {
-	size_t mmap_size = sysconf(_SC_PAGE_SIZE);
+	long page_size;
 	int wait_shm_fd, ret;
 	char *wait_shm_mmap;
 
-	wait_shm_fd = get_wait_shm(sock_info, mmap_size);
+	page_size = sysconf(_SC_PAGE_SIZE);
+	if (page_size < 0) {
+		goto error;
+	}
+
+	wait_shm_fd = get_wait_shm(sock_info, page_size);
 	if (wait_shm_fd < 0) {
 		goto error;
 	}
-	wait_shm_mmap = mmap(NULL, mmap_size, PROT_READ,
+	wait_shm_mmap = mmap(NULL, page_size, PROT_READ,
 		  MAP_SHARED, wait_shm_fd, 0);
 	/* close shm fd immediately after taking the mmap reference */
 	ret = close(wait_shm_fd);
diff --git a/tests/ust-basic-tracing/ust-basic-tracing.c b/tests/ust-basic-tracing/ust-basic-tracing.c
index 18fb0878..7bfeb5bc 100644
--- a/tests/ust-basic-tracing/ust-basic-tracing.c
+++ b/tests/ust-basic-tracing/ust-basic-tracing.c
@@ -642,11 +642,15 @@ error:
 
 int update_futex(int fd, int active)
 {
-	size_t mmap_size = sysconf(_SC_PAGE_SIZE);
+	long page_size;
 	char *wait_shm_mmap;
 	int ret;
 
-	wait_shm_mmap = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
+	page_size = sysconf(_SC_PAGE_SIZE);
+	if (page_size < 0) {
+		goto error;
+	}
+	wait_shm_mmap = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
 		  MAP_SHARED, fd, 0);
 	if (wait_shm_mmap == MAP_FAILED) {
 		perror("mmap");
@@ -660,7 +664,7 @@ int update_futex(int fd, int active)
 	} else {
 		uatomic_set((int32_t *) wait_shm_mmap, 0);
 	}
-	ret = munmap(wait_shm_mmap, mmap_size);
+	ret = munmap(wait_shm_mmap, page_size);
 	if (ret) {
 		perror("Error unmapping wait shm");
 		goto error;
diff --git a/tests/ust-multi-test/ust-multi-test.c b/tests/ust-multi-test/ust-multi-test.c
index 6f277a21..77711540 100644
--- a/tests/ust-multi-test/ust-multi-test.c
+++ b/tests/ust-multi-test/ust-multi-test.c
@@ -638,11 +638,15 @@ error:
 
 int update_futex(int fd, int active)
 {
-	size_t mmap_size = sysconf(_SC_PAGE_SIZE);
+	long page_size;
 	char *wait_shm_mmap;
 	int ret;
 
-	wait_shm_mmap = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
+	page_size = sysconf(_SC_PAGE_SIZE);
+	if (page_size < 0) {
+		goto error;
+	}
+	wait_shm_mmap = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
 		  MAP_SHARED, fd, 0);
 	if (wait_shm_mmap == MAP_FAILED) {
 		perror("mmap");
@@ -656,7 +660,7 @@ int update_futex(int fd, int active)
 	} else {
 		uatomic_set((int32_t *) wait_shm_mmap, 0);
 	}
-	ret = munmap(wait_shm_mmap, mmap_size);
+	ret = munmap(wait_shm_mmap, page_size);
 	if (ret) {
 		perror("Error unmapping wait shm");
 		goto error;