From 9b2c750d8e81da33cdf6e16db911faa2008652cd Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Tue, 20 Aug 2013 13:38:10 +0530 Subject: 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 Tested-by: Anton Kolesov Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman --- arch/arc/include/asm/ptrace.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arc/include') diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h index 6179de7e07c2..2046a89a57cf 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; }; }; -- cgit v1.2.3