Andy Lutomirski fc0e81b2be x86/traps: Ignore high word of regs->cs in early_fixup_exception() ... On the 80486 DX, it seems that some exceptions may leave garbage in the high bits of CS. This causes sporadic failures in which early_fixup_exception() refuses to fix up an exception. As far as I can tell, this has been buggy for a long time, but the problem seems to have been exacerbated by commits: 1e02ce4ccc ("x86: Store a per-cpu shadow copy of CR4") e1bfc11c5a ("x86/init: Fix cr4_init_shadow() on CR4-less machines") This appears to have broken for as long as we've had early exception handling. [ Note to stable maintainers: This patch is needed all the way back to 3.4, but it will only apply to 4.6 and up, as it depends on commit: 0e861fbb5b ("x86/head: Move early exception panic code into early_fixup_exception()") If you want to backport to kernels before 4.6, please don't backport the prerequisites (there was a big chain of them that rewrote a lot of the early exception machinery); instead, ask me and I can send you a one-liner that will apply. ] Reported-by: Matthew Whitehead <tedheadster@gmail.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 4c5023a3fa ("x86-32: Handle exception table entries during early boot") Link: http://lkml.kernel.org/r/cb32c69920e58a1a58e7b5cad975038a69c0ce7d.1479609510.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-11-21 08:06:54 +01:00
..
kmemcheck
amdtopology.c
debug_pagetables.c
dump_pagetables.c
extable.c	x86/traps: Ignore high word of regs->cs in early_fixup_exception()	2016-11-21 08:06:54 +01:00
fault.c	Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-11 23:38:39 -07:00
gup.c	mm: replace get_user_pages_unlocked() write/force parameters with gup_flags	2016-10-18 14:13:37 -07:00
highmem_32.c
hugetlbpage.c
ident_map.c
init_32.c
init_64.c
init.c
iomap_32.c
ioremap.c
kasan_init_64.c
kaslr.c	kconfig.h: remove config_enabled() macro	2016-10-27 18:43:43 -07:00
kmmio.c
Makefile
mm_internal.h
mmap.c
mmio-mod.c
mpx.c	mm: replace get_user_pages() write/force parameters with gup_flags	2016-10-19 08:11:43 -07:00
numa_32.c
numa_64.c
numa_emulation.c
numa_internal.h
numa.c
pageattr-test.c
pageattr.c
pat_internal.h
pat_rbtree.c
pat.c	x86/io: add interface to reserve io memtype for a resource range. (v1.1)	2016-10-26 15:45:38 +10:00
pf_in.c
pf_in.h
pgtable_32.c
pgtable.c
physaddr.c
physaddr.h
pkeys.c
setup_nx.c
srat.c
testmmiotrace.c
tlb.c