From: Christophe Leroy <christophe.leroy@xxxxxx>
Subject: selftests/vm: fix map_hugetlb length used for testing read and write
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().
Link: http://lkml.kernel.org/r/9a404a13c871c4bd0ba9ede68f69a1225180dd7e.1580978385.git.christophe.leroy@xxxxxx
Fixes: fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb")
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Reviewed-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/map_hugetlb.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- a/tools/testing/selftests/vm/map_hugetlb.c~selftests-vm-fix-map_hugetlb-length-used-for-testing-read-and-write
+++ a/tools/testing/selftests/vm/map_hugetlb.c
@@ -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);
}
_
