From af5e43cd88d4b7d59260de6bdacbf715e2a7ff5d Mon Sep 17 00:00:00 2001 From: Waldemar Brodkorb Date: Fri, 16 Oct 2020 01:17:24 +0200 Subject: [PATCH] Revert "ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE" This reverts commit 01b636cbc4c39c7073c02c2f1dfbe8c36c11938f. Signed-off-by: Waldemar Brodkorb --- arch/arc/kernel/entry.S | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 705a68208423..85d9ea4a0acc 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -156,6 +156,7 @@ END(EV_Extension) tracesys: ; save EFA in case tracer wants the PC of traced task ; using ERET won't work since next-PC has already committed + lr r12, [efa] GET_CURR_TASK_FIELD_PTR TASK_THREAD, r11 st r12, [r11, THREAD_FAULT_ADDR] ; thread.fault_address @@ -198,9 +199,15 @@ tracesys_exit: ; Breakpoint TRAP ; --------------------------------------------- trap_with_param: - mov r0, r12 ; EFA in case ptracer/gdb wants stop_pc + + ; stop_pc info by gdb needs this info + lr r0, [efa] mov r1, sp + ; Now that we have read EFA, it is safe to do "fake" rtie + ; and get out of CPU exception mode + FAKE_RET_FROM_EXCPN + ; Save callee regs in case gdb wants to have a look ; SP will grow up by size of CALLEE Reg-File ; NOTE: clobbers r12 @@ -227,10 +234,6 @@ ENTRY(EV_Trap) EXCEPTION_PROLOGUE - lr r12, [efa] - - FAKE_RET_FROM_EXCPN - ;============ TRAP 1 :breakpoints ; Check ECR for trap with arg (PROLOGUE ensures r9 has ECR) bmsk.f 0, r9, 7 @@ -238,6 +241,9 @@ ENTRY(EV_Trap) ;============ TRAP (no param): syscall top level + ; First return from Exception to pure K mode (Exception/IRQs renabled) + FAKE_RET_FROM_EXCPN + ; If syscall tracing ongoing, invoke pre-post-hooks GET_CURR_THR_INFO_FLAGS r10 btst r10, TIF_SYSCALL_TRACE -- 2.11.0