diff options
| author | Vineet Gupta <Vineet.Gupta1@synopsys.com> | 2013-08-20 13:38:10 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-29 09:47:29 -0700 |
| commit | 9b2c750d8e81da33cdf6e16db911faa2008652cd (patch) | |
| tree | 551cbb516890e8fe8d92d3d79714836529a82168 /arch | |
| parent | 6e4fdb803584635587bd4dc00d1f8c0883a02d3b (diff) | |
ARC: gdbserver breakage in Big-Endian configuration #1
[Based on mainline commit 502a0c775c7f0a: "ARC: pt_regs update #5"]
gdbserver needs @stop_pc, served by ptrace, but fetched from pt_regs
differently, based on in_brkpt_traps(), which in turn relies on
additional machine state in pt_regs->event bitfield.
unsigned long orig_r8:16, event:16;
For big endian config, this macro was returning false, despite being in
breakpoint Trap exception, causing wrong @stop_pc to be returned to gdb.
Issue #1: In BE, @event above is at offset 2 in word, while a STW insn
at offset 0 was used to update it. Resort to using ST insn
which updates the half-word at right location.
Issue #2: The union involving bitfields causes all the members to be
laid out at offset 0. So with fix #1 above, ASM was now
updating at offset 2, "C" code was still referencing at
offset 0. Fixed by wrapping bitfield in a struct.
Reported-by: Noam Camus <noamc@ezchip.com>
Tested-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arc/include/asm/ptrace.h | 2 | ||||
| -rw-r--r-- | arch/arc/kernel/entry.S | 4 |
2 files changed, 4 insertions, 2 deletions
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h index 6179de7e07c..2046a89a57c 100644 --- a/arch/arc/include/asm/ptrace.h +++ b/arch/arc/include/asm/ptrace.h @@ -52,12 +52,14 @@ struct pt_regs { /*to distinguish bet excp, syscall, irq */ union { + struct { #ifdef CONFIG_CPU_BIG_ENDIAN /* so that assembly code is same for LE/BE */ unsigned long orig_r8:16, event:16; #else unsigned long event:16, orig_r8:16; #endif + }; long orig_r8_word; }; }; diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 0c6d664d4a8..6dbe359c760 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -498,7 +498,7 @@ tracesys_exit: trap_with_param: ; stop_pc info by gdb needs this info - stw orig_r8_IS_BRKPT, [sp, PT_orig_r8] + st orig_r8_IS_BRKPT, [sp, PT_orig_r8] mov r0, r12 lr r1, [efa] @@ -723,7 +723,7 @@ not_exception: ; things to what they were, before returning from L2 context ;---------------------------------------------------------------- - ldw r9, [sp, PT_orig_r8] ; get orig_r8 to make sure it is + ld r9, [sp, PT_orig_r8] ; get orig_r8 to make sure it is brne r9, orig_r8_IS_IRQ2, 149f ; infact a L2 ISR ret path ld r9, [sp, PT_status32] ; get statu32_l2 (saved in pt_regs) |