x86/extable: ensure entries are swapped completely when sorting
The x86 exception table sorting was changed in commit 29934b0f ("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 548acf19 ("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. 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. [ Ard Biesheuvel points out that BUILDTIME_EXTABLE_SORT applies to the core image only, but we still rely on the sorting routines for modules in that case - Linus ] Fix this by providing a swap_ex_entry_fixup() macro that takes care of the 'handler' member. [1] https://lkml.org/lkml/2016/1/27/232Signed-off-by: Mathias Krause <minipli@googlemail.com> Fixes: 29934b0f ("x86/extable: use generic search and sort routines") Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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