From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Subject: selftest/mremap_test: avoid crash with static build With a large mmap map size, we can overlap with the text area and using MAP_FIXED results in unmapping that area. Switch to MAP_FIXED_NOREPLACE and handle the EEXIST error. Link: https://lkml.kernel.org/r/20210616045239.370802-3-aneesh.kumar@xxxxxxxxxxxxx Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Reviewed-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/vm/mremap_test.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/tools/testing/selftests/vm/mremap_test.c~selftest-mremap_test-avoid-crash-with-static-build +++ a/tools/testing/selftests/vm/mremap_test.c @@ -75,9 +75,10 @@ static void *get_source_mapping(struct c retry: addr += c.src_alignment; src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE, - MAP_FIXED | MAP_ANONYMOUS | MAP_SHARED, -1, 0); + MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED, + -1, 0); if (src_addr == MAP_FAILED) { - if (errno == EPERM) + if (errno == EPERM || errno == EEXIST) goto retry; goto error; } _