Re: [Kgdb-bugreport] [PATCH] kgdb, ppc: Corrected the address using of current->thread.evr register

[Kumar G. <ga...@ke...>]

On Nov 16, 2010, at 4:02 PM, Jason Wessel wrote:

> On 11/16/2010 06:58 AM, Dongdong Deng wrote:
>> Passing the address of current->thread.evr register to memcpy function.
>> 
>> 
> 
> It turns out that out of all of my test configs and targets I did not
> have any that defined both CONFIG_FSL_BOOKE and CONFIG_SPE else this
> would have been caught in testing because will definitely crash
> dereferencing the contents of the evr registers.
> 
>> Signed-off-by: Dongdong Deng <don...@wi...>
>> CC: Hai Shan <sha...@wi...>
>> CC: Milton Miller <mi...@bg...>
>> CC: lin...@li...
>> ---
>> arch/powerpc/kernel/kgdb.c |    4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
>> index 7a9db64..781acff 100644
>> --- a/arch/powerpc/kernel/kgdb.c
>> +++ b/arch/powerpc/kernel/kgdb.c
>> @@ -337,7 +337,7 @@ char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
>> 		/* FP registers 32 -> 63 */
>> #if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
>> 		if (current)
>> -			memcpy(mem, current->thread.evr[regno-32],
>> +			memcpy(mem, (void *)&current->thread.evr[regno-32],
>> 					dbg_reg_def[regno].size);
>> 
> 
> As Sergei already pointed out, the (void *) casts should not be needed here.
> 
> This would have been fixed correctly had I seen the compile warnings
> from the CONFIG_SPE at the test phase.   Namely at the compile phase
> doesn't even complete:
> 
> arch/powerpc/kernel/kgdb.c: In function 'dbg_get_reg':
> arch/powerpc/kernel/kgdb.c:341: error: passing argument 2 of 'memcpy'
> makes pointer from integer without a cast
> arch/powerpc/include/asm/string.h:25: note: expected 'const void *' but
> argument is of type 'long unsigned int'
> arch/powerpc/kernel/kgdb.c: In function 'dbg_set_reg':
> arch/powerpc/kernel/kgdb.c:366: error: passing argument 1 of 'memcpy'
> makes pointer from integer without a cast
> arch/powerpc/include/asm/string.h:25: note: expected 'void *' but
> argument is of type 'long unsigned int'
> 
> 
> Moral of the story... I now have a board and config with the SPE turned
> on, and after boot testing confirmed the evr registers are working.
> 
> I plan to have a pull request out to Linus with this fix and several
> other accumulated regression fixes sometime in the next 48 hours.
> 
> Thanks,
> Jason.

Repost a version with the casts and I'll pick it up.

- k