[Linux-kernel-mentees] [PATCH v3] drm/amdkfd: Fix undefined behavior in bit shift

Jiunn Chang c0d1n61at3 at gmail.com
Thu Jun 27 05:04:25 UTC 2019


Shifting signed 32-bit value by 31 bits is undefined.  Changing most
significant bit to unsigned.

Signed-off-by: Jiunn Chang <c0d1n61at3 at gmail.com>
---
Changes included in v3:
  - remove change log from patch description

Changes included in v2:
  - use subsystem specific subject lines
  - CC required mailing lists

 include/uapi/linux/kfd_ioctl.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h
index dc067ed0b72d..ae5669272303 100644
--- a/include/uapi/linux/kfd_ioctl.h
+++ b/include/uapi/linux/kfd_ioctl.h
@@ -339,7 +339,7 @@ struct kfd_ioctl_acquire_vm_args {
 #define KFD_IOC_ALLOC_MEM_FLAGS_USERPTR		(1 << 2)
 #define KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL	(1 << 3)
 /* Allocation flags: attributes/access options */
-#define KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE	(1 << 31)
+#define KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE	(1U << 31)
 #define KFD_IOC_ALLOC_MEM_FLAGS_EXECUTABLE	(1 << 30)
 #define KFD_IOC_ALLOC_MEM_FLAGS_PUBLIC		(1 << 29)
 #define KFD_IOC_ALLOC_MEM_FLAGS_NO_SUBSTITUTE	(1 << 28)
-- 
2.22.0



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