[prev in list] [next in list] [prev in thread] [next in thread] 

List:       gdb-patches
Subject:    [PATCH 2/2] [AArch64] Add more debugging output to aarch64_displaced_step_fixup
From:       luis.machado () linaro ! org (Luis Machado)
Date:       2019-12-30 16:50:00
Message-ID: a80e390e-967b-b80c-1aaf-b420bb198025 () linaro ! org
[Download RAW message or body]

cc-ing Alan.

On 12/30/19 1:25 PM, Luis Machado wrote:
> While debugging the step-over-syscall problem, i wanted to see a bit more
> debugging output to try to determine the root cause.
> 
> This patch does this.
> 
> gdb/ChangeLog:
> 
> 2019-12-30  Luis Machado  <luis.machado@linaro.org>
> 
> 	* aarch64-tdep.c (aarch64_displaced_step_fixup): Add more debugging
> 	output.
> 
> Signed-off-by: Luis Machado <luis.machado@linaro.org>
> ---
>   gdb/aarch64-tdep.c | 24 +++++++++++++++++++++++-
>   1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
> index a639b753cd..2d6c5a4bcb 100644
> --- a/gdb/aarch64-tdep.c
> +++ b/gdb/aarch64-tdep.c
> @@ -3058,8 +3058,16 @@ aarch64_displaced_step_fixup (struct gdbarch *gdbarch,
>     /* Fetch the current PC, after the displaced execution took place.  */
>     regcache_cooked_read_unsigned (regs, AARCH64_PC_REGNUM, &pc);
>   
> +  if (debug_displaced)
> +    debug_printf ("displaced: PC after stepping: %s (was %s).\n",
> +		  paddress (gdbarch, pc), paddress (gdbarch, to));
> +
>     if (dsc->cond)
>       {
> +      if (debug_displaced)
> +	debug_printf ("displaced: [Conditional] pc_adjust before: %d\n",
> +		      dsc->pc_adjust);
> +
>         if (pc - to == 8)
>   	{
>   	  /* Condition is true.  */
> @@ -3072,8 +3080,17 @@ aarch64_displaced_step_fixup (struct gdbarch *gdbarch,
>   	}
>         else
>   	gdb_assert_not_reached ("Unexpected PC value after displaced stepping");
> +
> +      if (debug_displaced)
> +	debug_printf ("displaced: [Conditional] pc_adjust after: %d\n",
> +		      dsc->pc_adjust);
>       }
>   
> +  if (debug_displaced)
> +    debug_printf ("displaced: %s PC by %d\n",
> +		  dsc->should_adjust_pc? "adjusting" : "not adjusting",
> +		  dsc->pc_adjust);
> +
>     if (dsc->should_adjust_pc)
>       {
>   
> @@ -3082,7 +3099,12 @@ aarch64_displaced_step_fixup (struct gdbarch *gdbarch,
>   	 and the instruction after the syscall instruction.  Make sure we don't
>   	 adjust the PC when we did not really move.  */
>         if ((pc - to) == 0)
> -	dsc->pc_adjust = 0;
> +	{
> +	  if (debug_displaced)
> +	    debug_printf ("displaced: PC did not move. Discarding PC \
> +adjustment.\n");
> +	  dsc->pc_adjust = 0;
> +	}
>   
>         if (debug_displaced)
>   	{
> 


[prev in list] [next in list] [prev in thread] [next in thread]