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Commit af289249 authored by Christophe Leroy's avatar Christophe Leroy Committed by Sasha Levin
Browse files

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: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarLeonardo Bras <leonardo@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/9a404a13c871c4bd0ba9ede68f69a1225180dd7e.1580978385.git.christophe.leroy@c-s.fr


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 71317d70

tools/testing/selftests/vm/map_hugetlb.c

+7 −7
Original line number Diff line number Diff line
@@ -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);

	}