Messages in this thread Patch in this message | | | Date | Fri, 22 Mar 2019 18:24:05 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 1/2] x86/MCE: Add function to allow filtering of MCA errors |
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On Thu, Mar 21, 2019 at 08:25:17PM +0000, Ghannam, Yazen wrote: > From: Yazen Ghannam <yazen.ghannam@amd.com> > > Some systems may report spurious MCA errors. In general, spurious MCA > errors may be disabled by clearing a particular bit in MCA_CTL. However, > clearing a bit in MCA_CTL may not be recommended for some errors, so the > only option is to ignore them. > > An MCA error is printed and handled after it has been added to the MCE > event pool. So an MCA error can be ignored by not adding it to the pool. > > Create a function pointer to filter MCA errors and use this when adding > an error to the MCE event pool. > > Install a default function that does not filter any errors. > > Cc: <stable@vger.kernel.org> # 4.14.x > Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> > --- > Link: > https://lkml.kernel.org/r/20190307212552.8865-1-Yazen.Ghannam@amd.com > > v1->v2: > * This is a new patch replacing V1 Patch 1 which is no longer needed. > > arch/x86/include/asm/mce.h | 3 +++ > arch/x86/kernel/cpu/mce/core.c | 6 ++++++ > arch/x86/kernel/cpu/mce/genpool.c | 3 +++ > 3 files changed, 12 insertions(+) > > diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h > index 22d05e3835f0..0b0b797a959c 100644 > --- a/arch/x86/include/asm/mce.h > +++ b/arch/x86/include/asm/mce.h > @@ -253,6 +253,9 @@ extern void mce_disable_bank(int bank); > extern void (*machine_check_vector)(struct pt_regs *, long error_code); > void do_machine_check(struct pt_regs *, long); > > +/* Filter MCEs from the decoder chain. */
That should be something like:
/* Decides whether to add MCE records to the decoder chain or filter them out. */
> +extern bool (*filter_mce)(struct mce *m); > + > /* > * Threshold handler > */ > diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c > index b7fb541a4873..effb40581f08 100644 > --- a/arch/x86/kernel/cpu/mce/core.c > +++ b/arch/x86/kernel/cpu/mce/core.c > @@ -1771,6 +1771,12 @@ static void __mcheck_cpu_init_timer(void) > mce_start_timer(t); > } > > +/* > + * Don't filter MCEs by default. Install a system-specific function, if needed. > + */
That comment is kinda obvious.
> +static bool default_filter_mce(struct mce *m) { return false; } > +bool (*filter_mce)(struct mce *) = default_filter_mce; > + > /* Handle unconfigured int18 (should never happen) */ > static void unexpected_machine_check(struct pt_regs *regs, long error_code) > { > diff --git a/arch/x86/kernel/cpu/mce/genpool.c b/arch/x86/kernel/cpu/mce/genpool.c > index 3395549c51d3..64d1d5a00f39 100644 > --- a/arch/x86/kernel/cpu/mce/genpool.c > +++ b/arch/x86/kernel/cpu/mce/genpool.c > @@ -99,6 +99,9 @@ int mce_gen_pool_add(struct mce *mce) > { > struct mce_evt_llist *node; > > + if (filter_mce(mce)) > + return -EINVAL; > + > if (!mce_evt_pool) > return -EINVAL; > > -- > 2.17.1 >
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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