Hello Christophe, thank you for the patch.
On Thu, 2020-02-06 at 08:42 +0000, Christophe Leroy wrote:
Commit fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb") added the possibility to change the size of memory mapped for the test, but left the read and write test using the default value. This is unnoticed when mapping a length greater than the default one, but segfaults otherwise.
Fix read_bytes() and write_bytes() by giving them the real length.
Also fix the call to munmap().
Fixes: fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy christophe.leroy@c-s.fr
tools/testing/selftests/vm/map_hugetlb.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/vm/map_hugetlb.c b/tools/testing/selftests/vm/map_hugetlb.c index 5a2d7b8efc40..6af951900aa3 100644 --- a/tools/testing/selftests/vm/map_hugetlb.c +++ b/tools/testing/selftests/vm/map_hugetlb.c @@ -45,20 +45,20 @@ static void check_bytes(char *addr) printf("First hex is %x\n", *((unsigned int *)addr)); } -static void write_bytes(char *addr) +static void write_bytes(char *addr, size_t length) { unsigned long i;
- for (i = 0; i < LENGTH; i++)
- for (i = 0; i < length; i++) *(addr + i) = (char)i;
} -static int read_bytes(char *addr) +static int read_bytes(char *addr, size_t length) { unsigned long i; check_bytes(addr);
- for (i = 0; i < LENGTH; i++)
- for (i = 0; i < length; i++) if (*(addr + i) != (char)i) { printf("Mismatch at %lu\n", i); return 1;
@@ -96,11 +96,11 @@ int main(int argc, char **argv) printf("Returned address is %p\n", addr); check_bytes(addr);
- write_bytes(addr);
- ret = read_bytes(addr);
- write_bytes(addr, length);
- ret = read_bytes(addr, length);
/* munmap() length of MAP_HUGETLB memory must be hugepage aligned */
- if (munmap(addr, LENGTH)) {
- if (munmap(addr, length)) { perror("munmap"); exit(1); }
I agree with you, it's a needed fix.
FWIW: Reviwed-by: Leonardo Bras leonardo@linux.ibm.com