When MAP_HUGETLB memory is unmapped, the length must be hugepage aligned, otherwise it fails with -EINVAL.
All tests currently behave correctly, but it's better to explcitly test the return value for completeness and document the requirement, especially if users copy map_hugetlb.c as a sample implementation. Signed-off-by: David Rientjes <[email protected]> --- tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c | 8 ++++++-- tools/testing/selftests/vm/hugetlbfstest.c | 4 +++- tools/testing/selftests/vm/map_hugetlb.c | 6 +++++- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c --- a/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c +++ b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c @@ -21,9 +21,13 @@ static int test_body(void) * Typically the mmap will fail because no huge pages are * allocated on the system. But if there are huge pages * allocated the mmap will succeed. That's fine too, we just - * munmap here before continuing. + * munmap here before continuing. munmap() length of + * MAP_HUGETLB memory must be hugepage aligned. */ - munmap(addr, SIZE); + if (munmap(addr, SIZE)) { + perror("munmap"); + return 1; + } } p = mmap(addr, SIZE, PROT_READ | PROT_WRITE, diff --git a/tools/testing/selftests/vm/hugetlbfstest.c b/tools/testing/selftests/vm/hugetlbfstest.c --- a/tools/testing/selftests/vm/hugetlbfstest.c +++ b/tools/testing/selftests/vm/hugetlbfstest.c @@ -34,6 +34,7 @@ static void do_mmap(int fd, int extra_flags, int unmap) int *p; int flags = MAP_PRIVATE | MAP_POPULATE | extra_flags; u64 before, after; + int ret; before = read_rss(); p = mmap(NULL, length, PROT_READ | PROT_WRITE, flags, fd, 0); @@ -44,7 +45,8 @@ static void do_mmap(int fd, int extra_flags, int unmap) !"rss didn't grow as expected"); if (!unmap) return; - munmap(p, length); + ret = munmap(p, length); + assert(!ret || !"munmap returned an unexpected error"); after = read_rss(); assert(llabs(after - before) < 0x40000 || !"rss didn't shrink as expected"); diff --git a/tools/testing/selftests/vm/map_hugetlb.c b/tools/testing/selftests/vm/map_hugetlb.c --- a/tools/testing/selftests/vm/map_hugetlb.c +++ b/tools/testing/selftests/vm/map_hugetlb.c @@ -73,7 +73,11 @@ int main(void) write_bytes(addr); ret = read_bytes(addr); - munmap(addr, LENGTH); + /* munmap() length of MAP_HUGETLB memory must be hugepage aligned */ + if (munmap(addr, LENGTH)) { + perror("munmap"); + exit(1); + } return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
