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- From af5e43cd88d4b7d59260de6bdacbf715e2a7ff5d Mon Sep 17 00:00:00 2001
- From: Waldemar Brodkorb <wbx@openadk.org>
- 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 <wbx@openadk.org>
- ---
- 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
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