In kernel_exit there is a alternative branch for KPTI which causes stack size conflict for two instruction boundaries. To fix that, make both branch move the sp and then revert it in tramp_exit branch. Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx> --- arch/arm64/kernel/entry.S | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index d49bfbe81a0d..677e3be471bb 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -430,7 +430,11 @@ alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0 ldr lr, [sp, #S_LR] add sp, sp, #PT_REGS_SIZE // restore sp eret -alternative_else_nop_endif +alternative_else + nop + add sp, sp, #PT_REGS_SIZE // restore sp + nop +alternative_endif #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 bne 4f msr far_el1, x29 @@ -729,6 +733,7 @@ alternative_else_nop_endif .macro tramp_exit, regsize = 64 UNWIND_HINT_EMPTY + sub sp, sp, #PT_REGS_SIZE // revert sp tramp_data_read_var x30, this_cpu_vector get_this_cpu_offset x29 ldr x30, [x30, x29] -- 2.17.1
