Re: [PATCH] Fix CFI interpretation for locations on DW_CFA_*_loc boundaries

[Milian Wolff <milian dot wolff at kdab dot com>]

Please ignore this patch for now - I only looked at one specific case where 
this changed the behavior to be in line with libunwind. Sadly, it breaks other 
previously working situations. I need to look at this in more detail.

Cheers

On Donnerstag, 1. November 2018 09:48:18 CET Milian Wolff wrote:
> According to the DWARF v3 standard §6.4.3 3., all call frame
> instructions up to L1 <= L2 should be interpreted for an FDE.
> Elfutils currently only interprets L1 < L2, potentially missing
> some instructions when L1 directly points at a DW_CFA_*_loc boundary.
> 
> This patch changes the behavior and makes elfutils behave like
> libunwind in that regard.
> ---
>  libdw/cfi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libdw/cfi.c b/libdw/cfi.c
> index 341e055b..332c6b8b 100644
> --- a/libdw/cfi.c
> +++ b/libdw/cfi.c
> @@ -125,7 +125,7 @@ execute_cfi (Dwarf_CFI *cache,
>      fs->regs[regno].value = (r_value);			\
>    } while (0)
> 
> -  while (program < end)
> +  while (program <= end)
>      {
>        uint8_t opcode = *program++;
>        Dwarf_Word regno;


-- 
Milian Wolff | milian.wolff@kdab.com | Senior Software Engineer
KDAB (Deutschland) GmbH, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt, C++ and OpenGL Experts

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