From: Rong Tao rongtao@cestc.cn
When testing overflow and overread, there is no need to keep unnecessary compilation warnings, we should simply ignore them.
How to reproduce the problem:
$ make -C tools/testing/selftests/ gcc huge_count_read_write.c -o /home/sd/Git/linux/tools/testing/selftests/damon/huge_count_read_write huge_count_read_write.c: In function ‘write_read_with_huge_count’: huge_count_read_write.c:23:9: warning: ‘write’ reading 4294967295 bytes from a region of size 1 [-Wstringop-overread] 23 | write(filedesc, "", 0xfffffffful); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from huge_count_read_write.c:8: /usr/include/unistd.h:378:16: note: in a call to function ‘write’ declared with attribute ‘access (read_only, 2, 3)’ 378 | extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur | ^~~~~ huge_count_read_write.c:25:15: warning: ‘read’ writing 4294967295 bytes into a region of size 25 overflows the destination [-Wstringop-overflow=] 25 | ret = read(filedesc, buf, 0xfffffffful); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ huge_count_read_write.c:14:14: note: destination object ‘buf’ of size 25 14 | char buf[25]; | ^~~ In file included from huge_count_read_write.c:8: /usr/include/unistd.h:371:16: note: in a call to function ‘read’ declared with attribute ‘access (write_only, 2, 3)’ 371 | extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur | ^~~~
Signed-off-by: Rong Tao rongtao@cestc.cn --- tools/testing/selftests/damon/huge_count_read_write.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/tools/testing/selftests/damon/huge_count_read_write.c b/tools/testing/selftests/damon/huge_count_read_write.c index ad7a6b4cf338..8fbe276870e7 100644 --- a/tools/testing/selftests/damon/huge_count_read_write.c +++ b/tools/testing/selftests/damon/huge_count_read_write.c @@ -8,6 +8,11 @@ #include <unistd.h> #include <stdio.h>
+#pragma GCC diagnostic push +/* Ignore read(2) overflow and write(2) overread compile warnings */ +#pragma GCC diagnostic ignored "-Wstringop-overread" +#pragma GCC diagnostic ignored "-Wstringop-overflow" + void write_read_with_huge_count(char *file) { int filedesc = open(file, O_RDWR); @@ -27,6 +32,8 @@ void write_read_with_huge_count(char *file) close(filedesc); }
+#pragma GCC diagnostic pop + int main(int argc, char *argv[]) { if (argc != 2) {