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

Shuah,

Le 06/02/2020 à 09:42, Christophe Leroy a écrit :

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

Can you also consider this one for next rc ?

Thanks Christophe

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); }