Re: [Libunwind-devel] [PATCH] coredump: simplify bad regnum checks a little

[Berat, Frederic (ADITG/SW1)]

Looking at the code snippet, there could also be a kind of "UNW_LAST_REG" value 
defined in architecture specific code. The "port me" complain would then be if 
this value is not defined.

Best regards

Frederic Berat
Software Group I (ADITG/SW1)

Tel. +49 5121 49 6935
> -----Original Message-----
> From: Libunwind-devel [mailto:libunwind-devel-bounces+fberat=de.adit-
> address@hidden On Behalf Of Mike Frysinger
> Sent: Dienstag, 14. Februar 2017 03:33
> To: address@hidden
> Subject: [Libunwind-devel] [PATCH] coredump: simplify bad regnum checks a
> little
> 
> We always want to reject negative regnums since we use it as an index, so
> make it a common check at the top for all arches.
> ---
>  src/coredump/_UCD_access_reg_linux.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/src/coredump/_UCD_access_reg_linux.c
> b/src/coredump/_UCD_access_reg_linux.c
> index 4b5994fad438..208d8d27b658 100644
> --- a/src/coredump/_UCD_access_reg_linux.c
> +++ b/src/coredump/_UCD_access_reg_linux.c
> @@ -39,17 +39,20 @@ _UCD_access_reg (unw_addr_space_t as,
>        return -UNW_EINVAL;
>      }
> 
> +  if (regnum < 0)
> +    goto badreg;
> +
>  #if defined(UNW_TARGET_AARCH64)
> -  if (regnum < 0 || regnum >= UNW_AARCH64_FPCR)
> +  if (regnum >= UNW_AARCH64_FPCR)
>      goto badreg;
>  #elif defined(UNW_TARGET_ARM)
> -  if (regnum < 0 || regnum >= 16)
> +  if (regnum >= 16)
>      goto badreg;
>  #elif defined(UNW_TARGET_SH)
> -  if (regnum < 0 || regnum > UNW_SH_PR)
> +  if (regnum > UNW_SH_PR)
>      goto badreg;
>  #elif defined(UNW_TARGET_TILEGX)
> -  if (regnum < 0 || regnum > UNW_TILEGX_CFA)
> +  if (regnum > UNW_TILEGX_CFA)
>      goto badreg;
>  #else
>  #if defined(UNW_TARGET_MIPS)
> @@ -120,7 +123,7 @@ _UCD_access_reg (unw_addr_space_t as,  #error
> Port me  #endif
> 
> -  if (regnum < 0 || regnum >= (unw_regnum_t)ARRAY_SIZE(remap_regs))
> +  if (regnum >= (unw_regnum_t)ARRAY_SIZE(remap_regs))
>      goto badreg;
> 
>    regnum = remap_regs[regnum];
> --
> 2.11.0
> 
> 
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