[PATCH] selftests/mm: add missing mmap() return checks in pkey tests

[Hongfu Li]

Several mmap() calls lack error checks and would crash on failure.
Add the missing checks. Also replace bare (void *)-1 with the
standard MAP_FAILED macro in protection_keys.c for consistency.

Signed-off-by: Hongfu Li <lihongfu@xxxxxxxxxx>
---
 tools/testing/selftests/mm/pkey_sighandler_tests.c | 2 ++
 tools/testing/selftests/mm/protection_keys.c       | 9 +++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index 302fef54049c..4637809192f9 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -317,6 +317,7 @@ static void test_sigsegv_handler_with_different_pkey_for_stack(void)
 	/* Set up alternate signal stack that will use the default MPK */
 	sigstack.ss_sp = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	assert(sigstack.ss_sp != MAP_FAILED);
 	sigstack.ss_flags = 0;
 	sigstack.ss_size = STACK_SIZE;
 
@@ -490,6 +491,7 @@ static void test_pkru_sigreturn(void)
 	/* Set up alternate signal stack that will use the default MPK */
 	sigstack.ss_sp = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	assert(sigstack.ss_sp != MAP_FAILED);
 	sigstack.ss_flags = 0;
 	sigstack.ss_size = STACK_SIZE;
 
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 2085982dba69..d53bdc540a74 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -667,7 +667,7 @@ static void *malloc_pkey_with_mprotect(long size, int prot, u16 pkey)
 			size, prot, pkey);
 	pkey_assert(pkey < NR_PKEYS);
 	ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 	ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
 	pkey_assert(!ret);
 	record_pkey_malloc(ptr, size, prot);
@@ -690,7 +690,7 @@ static void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
 	 */
 	size = ALIGN_UP(size, HPAGE_SIZE * 2);
 	ptr = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 	record_pkey_malloc(ptr, size, prot);
 	mprotect_pkey(ptr, size, prot, pkey);
 
@@ -770,7 +770,7 @@ static void *malloc_pkey_hugetlb(long size, int prot, u16 pkey)
 	size = ALIGN_UP(size, HPAGE_SIZE * 2);
 	pkey_assert(pkey < NR_PKEYS);
 	ptr = mmap(NULL, size, PROT_NONE, flags, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 	mprotect_pkey(ptr, size, prot, pkey);
 
 	record_pkey_malloc(ptr, size, prot);
@@ -1217,6 +1217,7 @@ static void arch_force_pkey_reg_init(void)
 	 * doing the XSAVE size enumeration dance.
 	 */
 	buf = mmap(NULL, 1*MB, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+	pkey_assert(buf != MAP_FAILED);
 
 	/* These __builtins require compiling with -mxsave */
 
@@ -1775,7 +1776,7 @@ int main(void)
 		printf("running PKEY tests for unsupported CPU/OS\n");
 
 		ptr  = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-		assert(ptr != (void *)-1);
+		assert(ptr != MAP_FAILED);
 		test_mprotect_pkey_on_unsupported_cpu(ptr, 1);
 		exit(0);
 	}
-- 
2.25.1