From 94cdc6a2c837d33e64d9453e9110d35af3833eda Mon Sep 17 00:00:00 2001 From: longlong yan Date: Wed, 22 Jul 2026 09:51:29 +0800 Subject: [PATCH] selftests/net: use MAP_FAILED instead of (void *)-1 in tcp_mmap mmap() is documented to return MAP_FAILED on error, but tcp_mmap.c compares the return value against (void *)-1 and (unsigned char *)-1. Replace these with the standard MAP_FAILED macro for better readability and type safety. Signed-off-by: longlong yan Reviewed-by: Joe Damato Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260722015129.916-1-yanlonglong@kylinos.cn Signed-off-by: Jakub Kicinski --- tools/testing/selftests/net/tcp_mmap.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c index 2544ae35d07a..487ae659a1f1 100644 --- a/tools/testing/selftests/net/tcp_mmap.c +++ b/tools/testing/selftests/net/tcp_mmap.c @@ -141,12 +141,12 @@ static void *mmap_large_buffer(size_t need, size_t *allocated) buffer = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0); - if (buffer == (void *)-1) { + if (buffer == MAP_FAILED) { sz = need; buffer = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0); - if (buffer != (void *)-1) + if (buffer != MAP_FAILED) fprintf(stderr, "MAP_HUGETLB attempt failed, look at /sys/kernel/mm/hugepages for optimal performance\n"); } *allocated = sz; @@ -189,13 +189,13 @@ void *child_thread(void *arg) fcntl(fd, F_SETFL, O_NDELAY); buffer = mmap_large_buffer(chunk_size, &buffer_sz); - if (buffer == (void *)-1) { + if (buffer == MAP_FAILED) { perror("mmap"); goto error; } if (zflg) { raddr = mmap(NULL, chunk_size + map_align, PROT_READ, flags, fd, 0); - if (raddr == (void *)-1) { + if (raddr == MAP_FAILED) { perror("mmap"); zflg = 0; } else { @@ -547,7 +547,7 @@ int main(int argc, char *argv[]) } buffer = mmap_large_buffer(chunk_size, &buffer_sz); - if (buffer == (unsigned char *)-1) { + if (buffer == MAP_FAILED) { perror("mmap"); exit(1); }