Messages in this thread | | | Date | Wed, 11 May 2016 08:06:27 +0200 | Subject | Re: [PATCH] x86/extable: ensure entries are swapped completely when sorting | From | Mathias Krause <> |
| |
On 11 May 2016 at 07:46, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > On 10 May 2016 at 23:07, Mathias Krause <minipli@googlemail.com> wrote: >> The x86 exception table sorting was changed in commit 29934b0fb8ff >> ("x86/extable: use generic search and sort routines") to use the arch >> independent code in lib/extable.c. However, the patch was mangled >> somehow on its way into the kernel from the last version posted at [1]. >> The committed version kind of attempted to incorporate the changes of >> commit 548acf19234d ("x86/mm: Expand the exception table logic to allow >> new handling options") as in _completely_ _ignoring_ the x86 specific >> 'handler' member of struct exception_table_entry. This effectively broke >> the sorting as entries will only partly be swapped now. >> > > OK, it appears that Tony's patches grew a 'handler' field fairly late > in their review cycle, and I didn't pick up on that. Apologies.
No need to apologize, as your patch *must* have created conflicts for the committer applying it. It's just that those conflicts were resolved wrongly. He/She should have asked you for a new version, but... did not :/
>> Fortunately, the x86 Kconfig selects BUILDTIME_EXTABLE_SORT, so the >> exception table doesn't need to be sorted at runtime. However, in case >> that ever changes, we better not break the exception table sorting just >> because of that. >> > > BUILDTIME_EXTABLE_SORT applies to the core image only, but we still > rely on the sorting routines for modules in that case. So I think this > needs to be fixed right away.
Good point!
> >> Fix this by providing a swap_ex_entry_fixup() macro that takes care of >> the 'handler' member. >> >> [1] https://lkml.org/lkml/2016/1/27/232 >> >> Signed-off-by: Mathias Krause <minipli@googlemail.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Andy Lutomirski <luto@kernel.org> >> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> Cc: Borislav Petkov <bp@suse.de> >> Cc: H. Peter Anvin <hpa@linux.intel.com> >> Cc: Ingo Molnar <mingo@kernel.org> >> Cc: Linus Torvalds <torvalds@linux-foundation.org> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Tony Luck <tony.luck@intel.com> > > Fixes: 29934b0fb8f ("x86/extable: use generic search and sort routines") > Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > Thanks, > Ard. >
Thanks, Mathias
| |