Re: gdb gets confused with o32 core files, WANT_COMPAT_REG_H needed?

[Martin Michlmayr <tbm@cyrius.com>]

* Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com> [2005-08-22 17:08]:
> I've been trying to fix core file support for 64bit kernel with o32
> userspace (working against 2.6.12 cvs tag).
> 
> After applying the patch posted on 13 Feb 2005 from Daniel Jacobowitz
> to fix binfmt_elfo32.c (any reason this didn't make it into CVS?),
> I still ran into trouble with gdb not understanding the NT_PRSTATUS
> header in the core file.
> 
> While Dan's fix makes the kernel use elf32 definitions, gdb was still
> getting confused by pr_reg contained in the core file.
> 
> Dan's definition of ELF_CORE_COPY_REGS in binfmt_elfo32.c is copying
> the registers using EF_R0 as 0 not 6 producing results into offset 0
> through 37 not 6 through 43 as gdb expects for 32bit core files.
> 
> Below patch (applied after Dan's patch) writes the registers at offset
> 6 making gdb much happier.

* Daniel Jacobowitz <dan@debian.org> [2005-08-28 11:45]:
> > Below patch (applied after Dan's patch) writes the registers at offset
> > 6 making gdb much happier.
> 
> FYI, this has all been rearranged since - it did this correctly at the
> time.  I don't know why the patch was dropped.

Can this be applied?


> Fix o32 core files under 64bit kernel to use correct register
> offset in NT_PRSTATUS
> 
> Signed-off-by: Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com>
> 
> ===== arch/mips/kernel/binfmt_elfo32.c 1.7 vs edited =====
> --- 1.7/arch/mips/kernel/binfmt_elfo32.c	2005-08-20 12:30:12 -04:00
> +++ edited/arch/mips/kernel/binfmt_elfo32.c	2005-08-22 16:09:59 -04:00
> @@ -51,6 +51,7 @@
>  #define TASK32_SIZE		0x7fff8000UL
>  #undef ELF_ET_DYN_BASE
>  #define ELF_ET_DYN_BASE         (TASK32_SIZE / 3 * 2)
> +#define WANT_COMPAT_REG_H
>  
>  #include <asm/processor.h>
>  #include <linux/module.h>
> ===== include/asm-mips/reg.h 1.1 vs edited =====
> --- 1.1/include/asm-mips/reg.h	2005-02-02 11:39:14 -05:00
> +++ edited/include/asm-mips/reg.h	2005-08-22 15:55:04 -04:00
> @@ -70,7 +70,7 @@
>  
>  #endif
>  
> -#if CONFIG_MIPS64
> +#if defined(CONFIG_MIPS64) && !defined(WANT_COMPAT_REG_H)
>  
>  #define EF_R0			 0
>  #define EF_R1			 1
> 

-- 
Martin Michlmayr
http://www.cyrius.com/