Messages in this thread | | | Date | Tue, 10 Nov 2015 12:21:16 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH 1/3] x86, ras: Add new infrastructure for machine check fixup tables |
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On Fri, Nov 06, 2015 at 12:57:03PM -0800, Tony Luck wrote: > Copy the existing page fault fixup mechanisms to create a new table > to be used when fixing machine checks. Note: > 1) At this time we only provide a macro to annotate assembly code > 2) We assume all fixups will in code builtin to the kernel. > > Signed-off-by: Tony Luck <tony.luck@intel.com> > --- > arch/x86/include/asm/asm.h | 7 +++++++ > arch/x86/include/asm/uaccess.h | 1 + > arch/x86/mm/extable.c | 16 ++++++++++++++++ > include/asm-generic/vmlinux.lds.h | 6 ++++++ > include/linux/module.h | 1 + > kernel/extable.c | 14 ++++++++++++++ > 6 files changed, 45 insertions(+) > > diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h > index 189679aba703..f2fa7973f18f 100644 > --- a/arch/x86/include/asm/asm.h > +++ b/arch/x86/include/asm/asm.h > @@ -58,6 +58,13 @@ > .long (to) - . + 0x7ffffff0 ; \ > .popsection > > +# define _ASM_MCEXTABLE(from, to) \
Maybe add an intermediary macro which abstracts the table name:
#define __ASM_EXTABLE(from, to, table) ...
and then do
#define _ASM_EXTABLE(from, to) __ASM_EXTABLE(from, to, "__ex_table") #define _ASM_MCEXTABLE(from, to) __ASM_EXTABLE(from, to, "__mcex_table")
> + .pushsection "__mcex_table", "a" ; \ > + .balign 8 ; \ > + .long (from) - . ; \ > + .long (to) - . ; \ > + .popsection > + > # define _ASM_NOKPROBE(entry) \ > .pushsection "_kprobe_blacklist","aw" ; \ > _ASM_ALIGN ; \ > diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h > index a8df874f3e88..b8231301a224 100644 > --- a/arch/x86/include/asm/uaccess.h > +++ b/arch/x86/include/asm/uaccess.h > @@ -111,6 +111,7 @@ struct exception_table_entry { > #define ARCH_HAS_SEARCH_EXTABLE > > extern int fixup_exception(struct pt_regs *regs); > +extern int fixup_mcexception(struct pt_regs *regs); > extern int early_fixup_exception(unsigned long *ip); > > /* > diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c > index 903ec1e9c326..5b328ae00365 100644 > --- a/arch/x86/mm/extable.c > +++ b/arch/x86/mm/extable.c > @@ -49,6 +49,22 @@ int fixup_exception(struct pt_regs *regs) > return 0; > } > > +int fixup_mcexception(struct pt_regs *regs) > +{ > + const struct exception_table_entry *fixup; > + unsigned long new_ip; > + > + fixup = search_mcexception_tables(regs->ip); > + if (fixup) { > + new_ip = ex_fixup_addr(fixup); > + > + regs->ip = new_ip; > + return 1; > + } > + > + return 0; > +}
Yeah, all that duplication might raise some brows but I'd guess special-handling MCA in the normal exception paths might make the code a bit too ugly...
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply.
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