When taking an exception/interrupt, add UNWIND_HINT_REGS to indicate from which point the pt_regs is on stack. Whether returning to userland or creating a new task, sp is pointing to a pt_regs frame, add UNWIND_HINT_REGS after that. Signed-off-by: Julien Thierry <jthierry@xxxxxxxxxx> Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx> --- arch/arm64/kernel/entry.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3bd11101e79d..bbc440379304 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -120,6 +120,7 @@ alternative_cb spectre_v4_patch_fw_mitigation_enable b .L__asm_ssbd_skip\@ // Patched to NOP alternative_cb_end + UNWIND_HINT_REGS ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1 cbz \tmp2, .L__asm_ssbd_skip\@ ldr \tmp2, [tsk, #TSK_TI_FLAGS] @@ -218,6 +219,7 @@ alternative_cb_end stp x24, x25, [sp, #16 * 12] stp x26, x27, [sp, #16 * 13] stp x28, x29, [sp, #16 * 14] + UNWIND_HINT_REGS .if \el == 0 clear_gp_regs @@ -601,6 +603,7 @@ SYM_CODE_START_LOCAL(ret_to_kernel) SYM_CODE_END(ret_to_kernel) SYM_CODE_START_LOCAL(ret_to_user) + UNWIND_HINT_REGS ldr x19, [tsk, #TSK_TI_FLAGS] // re-check for single-step enable_step_tsk x19, x2 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK @@ -872,6 +875,7 @@ NOKPROBE(cpu_switch_to) * This is how we return from a fork. */ SYM_CODE_START(ret_from_fork) + UNWIND_HINT_REGS bl schedule_tail cbz x19, 1f // not a kernel thread mov x0, x20 -- 2.17.1
