From 106c5ff7e52083dd8c257ef926e03dc078e87c8f Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 1 Apr 2020 21:11:51 -0700 Subject: [PATCH] selftests/vm: fix map_hugetlb length used for testing read and write [ Upstream commit cabc30da10e677c67ab9a136b1478175734715c5 ] 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") Signed-off-by: Christophe Leroy Signed-off-by: Andrew Morton Reviewed-by: Leonardo Bras Cc: Michael Ellerman Cc: Shuah Khan Cc: Link: http://lkml.kernel.org/r/9a404a13c871c4bd0ba9ede68f69a1225180dd7e.1580978385.git.christophe.leroy@c-s.fr Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- 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 7b41cc6ecb0b..c65c55b7a789 100644 --- a/tools/testing/selftests/vm/map_hugetlb.c +++ b/tools/testing/selftests/vm/map_hugetlb.c @@ -46,20 +46,20 @@ 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; @@ -103,11 +103,11 @@ 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); }