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authorVineet Gupta <Vineet.Gupta1@synopsys.com>2013-08-20 13:38:10 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-29 09:47:29 -0700
commit9b2c750d8e81da33cdf6e16db911faa2008652cd (patch)
tree551cbb516890e8fe8d92d3d79714836529a82168 /arch/arc
parent6e4fdb803584635587bd4dc00d1f8c0883a02d3b (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/arc')
-rw-r--r--arch/arc/include/asm/ptrace.h2
-rw-r--r--arch/arc/kernel/entry.S4
2 files changed, 4 insertions, 2 deletions
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;
};
};
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 0c6d664d4a83..6dbe359c760d 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)