Since the offset would be bitwise ANDed with 0x3FF in
add_random_kstack_offset(), so just remove AND operation here.
Signed-off-by: Yuntao Liu <liuyuntao12@xxxxxxxxxx>
---
arch/arm64/kernel/syscall.c | 2 +-
arch/s390/include/asm/entry-common.h | 2 +-
arch/x86/include/asm/entry-common.h | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index ad198262b981..43f555f7cd2d 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -63,7 +63,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
*
* The resulting 5 bits of entropy is seen in SP[8:4].
*/
- choose_random_kstack_offset(get_random_u16() & 0x1FF);
+ choose_random_kstack_offset(get_random_u16());
}
static inline bool has_syscall_work(unsigned long flags)
diff --git a/arch/s390/include/asm/entry-common.h b/arch/s390/include/asm/entry-common.h
index 7f5004065e8a..35555c944630 100644
--- a/arch/s390/include/asm/entry-common.h
+++ b/arch/s390/include/asm/entry-common.h
@@ -54,7 +54,7 @@ static __always_inline void arch_exit_to_user_mode(void)
static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
unsigned long ti_work)
{
- choose_random_kstack_offset(get_tod_clock_fast() & 0xff);
+ choose_random_kstack_offset(get_tod_clock_fast());
}
#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h
index 7e523bb3d2d3..b28a307f2014 100644
--- a/arch/x86/include/asm/entry-common.h
+++ b/arch/x86/include/asm/entry-common.h
@@ -85,7 +85,7 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
* Therefore, final stack offset entropy will be 5 (x86_64) or
* 6 (ia32) bits.
*/
- choose_random_kstack_offset(rdtsc() & 0xFF);
+ choose_random_kstack_offset(rdtsc());
}
#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
--
2.34.1
