From dd9cef43c222df7c0d76d34451808e789952379d Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Tue, 5 Feb 2019 15:12:34 -0200 Subject: [PATCH] bpf: test_maps: fix possible out of bound access warning MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When compiling test_maps selftest with GCC-8, it warns that an array might be indexed with a negative value, which could cause a negative out of bound access, depending on parameters of the function. This is the GCC-8 warning: gcc -Wall -O2 -I../../../include/uapi -I../../../lib -I../../../lib/bpf -I../../../../include/generated -DHAVE_GENHDR -I../../../include test_maps.c /home/breno/Devel/linux/tools/testing/selftests/bpf/libbpf.a -lcap -lelf -lrt -lpthread -o /home/breno/Devel/linux/tools/testing/selftests/bpf/test_maps In file included from test_maps.c:16: test_maps.c: In function ‘run_all_tests’: test_maps.c:1079:10: warning: array subscript -1 is below array bounds of ‘pid_t[ + 1]’ [-Warray-bounds] assert(waitpid(pid[i], &status, 0) == pid[i]); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ test_maps.c:1059:6: warning: array subscript -1 is below array bounds of ‘pid_t[ + 1]’ [-Warray-bounds] pid[i] = fork(); ~~~^~~ This patch simply guarantees that the task(s) variables are unsigned, thus, they could never be a negative number (which they are not in current code anyway), hence avoiding an out of bound access warning. Signed-off-by: Breno Leitao Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_maps.c | 27 +++++++++++++------------ 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c index e7798dd97f4b..3c627771f965 100644 --- a/tools/testing/selftests/bpf/test_maps.c +++ b/tools/testing/selftests/bpf/test_maps.c @@ -45,7 +45,7 @@ static int map_flags; } \ }) -static void test_hashmap(int task, void *data) +static void test_hashmap(unsigned int task, void *data) { long long key, next_key, first_key, value; int fd; @@ -135,7 +135,7 @@ static void test_hashmap(int task, void *data) close(fd); } -static void test_hashmap_sizes(int task, void *data) +static void test_hashmap_sizes(unsigned int task, void *data) { int fd, i, j; @@ -155,7 +155,7 @@ static void test_hashmap_sizes(int task, void *data) } } -static void test_hashmap_percpu(int task, void *data) +static void test_hashmap_percpu(unsigned int task, void *data) { unsigned int nr_cpus = bpf_num_possible_cpus(); BPF_DECLARE_PERCPU(long, value); @@ -282,7 +282,7 @@ static int helper_fill_hashmap(int max_entries) return fd; } -static void test_hashmap_walk(int task, void *data) +static void test_hashmap_walk(unsigned int task, void *data) { int fd, i, max_entries = 1000; long long key, value, next_key; @@ -353,7 +353,7 @@ static void test_hashmap_zero_seed(void) close(second); } -static void test_arraymap(int task, void *data) +static void test_arraymap(unsigned int task, void *data) { int key, next_key, fd; long long value; @@ -408,7 +408,7 @@ static void test_arraymap(int task, void *data) close(fd); } -static void test_arraymap_percpu(int task, void *data) +static void test_arraymap_percpu(unsigned int task, void *data) { unsigned int nr_cpus = bpf_num_possible_cpus(); BPF_DECLARE_PERCPU(long, values); @@ -504,7 +504,7 @@ static void test_arraymap_percpu_many_keys(void) close(fd); } -static void test_devmap(int task, void *data) +static void test_devmap(unsigned int task, void *data) { int fd; __u32 key, value; @@ -519,7 +519,7 @@ static void test_devmap(int task, void *data) close(fd); } -static void test_queuemap(int task, void *data) +static void test_queuemap(unsigned int task, void *data) { const int MAP_SIZE = 32; __u32 vals[MAP_SIZE + MAP_SIZE/2], val; @@ -577,7 +577,7 @@ static void test_queuemap(int task, void *data) close(fd); } -static void test_stackmap(int task, void *data) +static void test_stackmap(unsigned int task, void *data) { const int MAP_SIZE = 32; __u32 vals[MAP_SIZE + MAP_SIZE/2], val; @@ -642,7 +642,7 @@ static void test_stackmap(int task, void *data) #define SOCKMAP_PARSE_PROG "./sockmap_parse_prog.o" #define SOCKMAP_VERDICT_PROG "./sockmap_verdict_prog.o" #define SOCKMAP_TCP_MSG_PROG "./sockmap_tcp_msg_prog.o" -static void test_sockmap(int tasks, void *data) +static void test_sockmap(unsigned int tasks, void *data) { struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_msg, *bpf_map_break; int map_fd_msg = 0, map_fd_rx = 0, map_fd_tx = 0, map_fd_break; @@ -1268,10 +1268,11 @@ static void test_map_large(void) } #define run_parallel(N, FN, DATA) \ - printf("Fork %d tasks to '" #FN "'\n", N); \ + printf("Fork %u tasks to '" #FN "'\n", N); \ __run_parallel(N, FN, DATA) -static void __run_parallel(int tasks, void (*fn)(int task, void *data), +static void __run_parallel(unsigned int tasks, + void (*fn)(unsigned int task, void *data), void *data) { pid_t pid[tasks]; @@ -1312,7 +1313,7 @@ static void test_map_stress(void) #define DO_UPDATE 1 #define DO_DELETE 0 -static void test_update_delete(int fn, void *data) +static void test_update_delete(unsigned int fn, void *data) { int do_update = ((int *)data)[1]; int fd = ((int *)data)[0]; -- 2.30.2