This is the mail archive of the
gdb@sourceware.org
mailing list for the GDB project.
Re: Problem with GDB when debugging IRQ handlers
On Tue, Jun 28, 2011 at 04:45:52PM +0100, Dmitry Eremin-Solenikov wrote:
> Here is a part of gdb log generated using the attached patch:
[...]
> #11 0xc0033810 in kernel_thread_helper ()
> #12 0xc0033810 in kernel_thread_helper ()
> Backtrace stopped: previous frame identical to this frame (corrupt stack?)
Maybe you can add something similar to the kernel_thread_helper in
arch/arm/kernel/process.c? I'm not sure whether there is something like
.cantunwind (as for the kernel unwinding information).
> diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
> index e8d8856..44daf40 100644
> --- a/arch/arm/kernel/entry-armv.S
> +++ b/arch/arm/kernel/entry-armv.S
> @@ -28,6 +28,7 @@
> #include "entry-header.S"
> #include <asm/entry-macro-multi.S>
>
> + .cfi_sections .debug_frame
> /*
> * Interrupt handling. Preserves r7, r8, r9
> */
> @@ -113,6 +114,7 @@ ENDPROC(__und_invalid)
>
> .macro svc_entry, stack_hole=0
> UNWIND(.fnstart )
> + .cfi_startproc
> UNWIND(.save {r0 - pc} )
> sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
> #ifdef CONFIG_THUMB2_KERNEL
> @@ -146,6 +148,24 @@ ENDPROC(__und_invalid)
> @ r4 - orig_r0 (see pt_regs definition in ptrace.h)
> @
> stmia r5, {r0 - r4}
> + .cfi_def_cfa_offset S_PC + 4
> + .cfi_offset 14, -4
> +#define CFI_REG_OFF(r) .cfi_offset r, (r - 16) * 4
> + CFI_REG_OFF(13)
> + CFI_REG_OFF(12)
> + CFI_REG_OFF(11)
> + CFI_REG_OFF(10)
> + CFI_REG_OFF(9)
> + CFI_REG_OFF(8)
> + CFI_REG_OFF(7)
> + CFI_REG_OFF(6)
> + CFI_REG_OFF(5)
> + CFI_REG_OFF(4)
> + CFI_REG_OFF(3)
> + CFI_REG_OFF(2)
> + CFI_REG_OFF(1)
> + CFI_REG_OFF(0)
> +#undef CFI_REG_OFF
> .endm
Do we need all the registers in here for gdb stack unwinding? In general
we would only need LR, SP and FP.
--
Catalin