selftests/vm: fix map_hugetlb length used for testing read and write

Commit fa7b9a805c ("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: fa7b9a805c ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Leonardo 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: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christophe Leroy 2020-04-01 21:11:51 -07:00 committed by Linus Torvalds
parent d4af73e3f8
commit cabc30da10

View File

@ -45,20 +45,20 @@ 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;
@ -96,11 +96,11 @@ 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);
}