Re: [GIT PULL] L3 CID fix for 3.5

From: Borislav Petkov
Date: Wed Apr 25 2012 - 05:30:21 EST


Ping?

Guys, any issues with this that I should know of?

Thanks.

On Thu, Apr 19, 2012 at 06:53:53PM +0200, Borislav Petkov wrote:
> Hi guys,
>
> please pull the following fix for L3 cache index disable into tip. Since
> there's no real breakage but simply a correctness issue, it can wait for
> 3.5. I've also removed the stable tag I had in the previous version.
>
> Thanks.
>
> --
> The following changes since commit e816b57a337ea3b755de72bec38c10c864f23015:
>
> Linux 3.4-rc3 (2012-04-15 18:28:29 -0700)
>
> are available in the git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git tags/l3-fix-for-3.5
>
> for you to fetch changes up to a720b2dd2470a52345df11dca8d6c1466599f812:
>
> x86, intel_cacheinfo: Fix error return code in amd_set_l3_disable_slot() (2012-04-19 18:30:28 +0200)
>
> ----------------------------------------------------------------
> A small L3 cache index disable fix from Srivatsa Bhat which unifies the
> way the code checks for already disabled indices.
>
> ----------------------------------------------------------------
> Srivatsa S. Bhat (1):
> x86, intel_cacheinfo: Fix error return code in amd_set_l3_disable_slot()
>
> arch/x86/kernel/cpu/intel_cacheinfo.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> Appending patch here too:
>
> --
> commit a720b2dd2470a52345df11dca8d6c1466599f812
> Author: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> Date: Thu Apr 19 12:35:08 2012 +0200
>
> x86, intel_cacheinfo: Fix error return code in amd_set_l3_disable_slot()
>
> If the L3 disable slot is already in use, return -EEXIST instead of
> -EINVAL. The caller, store_cache_disable(), checks this return value to
> print an appropriate warning.
>
> Also, we want to signal with -EEXIST that the current index we're
> disabling has actually been already disabled on the node:
>
> $ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_0
> $ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_0
> -bash: echo: write error: File exists
> $ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_1
> -bash: echo: write error: File exists
> $ echo 12 > /sys/devices/system/cpu/cpu5/cache/index3/cache_disable_1
> -bash: echo: write error: File exists
>
> The old code would say
>
> -bash: echo: write error: Invalid argument
>
> for disable slot 1 when playing the example above with no output in
> dmesg, which is clearly misleading.
>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> Link: http://lkml.kernel.org/r/20120419070053.GB16645@xxxxxxxxxxxxxx
> [Boris: add testing for the other index too]
> Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
>
> diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
> index 73d08ed98a64..b8f3653dddbc 100644
> --- a/arch/x86/kernel/cpu/intel_cacheinfo.c
> +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
> @@ -433,14 +433,14 @@ int amd_set_l3_disable_slot(struct amd_northbridge *nb, int cpu, unsigned slot,
> /* check if @slot is already used or the index is already disabled */
> ret = amd_get_l3_disable_slot(nb, slot);
> if (ret >= 0)
> - return -EINVAL;
> + return -EEXIST;
>
> if (index > nb->l3_cache.indices)
> return -EINVAL;
>
> /* check whether the other slot has disabled the same index already */
> if (index == amd_get_l3_disable_slot(nb, !slot))
> - return -EINVAL;
> + return -EEXIST;
>
> amd_l3_disable_index(nb, cpu, slot, index);
>
> @@ -468,8 +468,8 @@ static ssize_t store_cache_disable(struct _cpuid4_info *this_leaf,
> err = amd_set_l3_disable_slot(this_leaf->base.nb, cpu, slot, val);
> if (err) {
> if (err == -EEXIST)
> - printk(KERN_WARNING "L3 disable slot %d in use!\n",
> - slot);
> + pr_warning("L3 slot %d in use/index already disabled!\n",
> + slot);
> return err;
> }
> return count;
>
> --
> Regards/Gruss,
> Boris.
>
> Advanced Micro Devices GmbH
> Einsteinring 24, 85609 Dornach
> GM: Alberto Bozzo
> Reg: Dornach, Landkreis Muenchen
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--
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

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