[PATCH v2 2/6] selftest/mremap_test: Avoid crash with static build

Aneesh Kumar K.V aneesh.kumar at linux.ibm.com
Wed Jun 16 14:52:35 AEST 2021


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.

Reviewed-by: Kalesh Singh <kaleshsingh at google.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
---
 tools/testing/selftests/vm/mremap_test.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vm/mremap_test.c b/tools/testing/selftests/vm/mremap_test.c
index c9a5461eb786..0624d1bd71b5 100644
--- a/tools/testing/selftests/vm/mremap_test.c
+++ b/tools/testing/selftests/vm/mremap_test.c
@@ -75,9 +75,10 @@ static void *get_source_mapping(struct config 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;
 	}
-- 
2.31.1



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