[PATCH AUTOSEL 5.13 06/19] s390: add kmemleak annotation in stack_alloc()

Sasha Levin
2021-09-13T22:35:58Z

From: Sven Schnelle <svens@linux.ibm.com>

[ Upstream commit 436fc4feeabbf103d78d50a8e091b3aac28cc37f ]

kmemleak with enabled auto scanning reports that our stack allocation is
lost. This is because we're saving the pointer + STACK_INIT_OFFSET to
lowcore. When kmemleak now scans the objects, it thinks that this one is
lost because it can't find a corresponding pointer.

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/s390/kernel/setup.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 93538e63fa03..442150c88278 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -50,6 +50,7 @@
#include <linux/compat.h>
#include <linux/start_kernel.h>
#include <linux/hugetlb.h>
+#include <linux/kmemleak.h>

#include <asm/boot_data.h>
#include <asm/ipl.h>
@@ -310,9 +311,12 @@ void *restart_stack;
unsigned long stack_alloc(void)
{
#ifdef CONFIG_VMAP_STACK
- return (unsigned long)__vmalloc_node(THREAD_SIZE, THREAD_SIZE,
- THREADINFO_GFP, NUMA_NO_NODE,
- __builtin_return_address(0));
+ void *ret;
+
+ ret = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
+ NUMA_NO_NODE, __builtin_return_address(0));
+ kmemleak_not_leak(ret);
+ return (unsigned long)ret;
#else
return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
#endif
--
2.30.2