linux

iv/linux

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Christophe Leroy c0ec202951 powerpc/32: Preserve cr1 in exception prolog stack check to fix build error

commit 3642eb21256a317ac14e9ed560242c6d20cf06d9 upstream.

THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1
Maximum PAGE_SHIFT is 18 for 256k pages so
THREAD_ALIGN_SHIFT is 19 at the maximum.

No need to clobber cr1, it can be preserved when moving r1
into CR when we check stack overflow.

This reduces the number of instructions in Machine Check Exception
prolog and fixes a build failure reported by the kernel test robot
on v5.10 stable when building with RTAS + VMAP_STACK + KVM. That
build failure is due to too many instructions in the prolog hence
not fitting between 0x200 and 0x300. Allthough the problem doesn't
show up in mainline, it is still worth the change.

Fixes: 98bf2d3f4970 ("powerpc/32s: Fix RTAS machine check with VMAP stack")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5ae4d545e3ac58e133d2599e0deb88843cb494fc.1612768623.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2021-03-04 11:38:39 +01:00

alpha

local64.h: make <asm/local64.h> mandatory

2021-01-12 20:18:16 +01:00

arc

arch/arc: add copy_user_page() to <asm/page.h> to fix build error on ARC

2021-01-19 18:27:26 +01:00

arm

ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled

2021-03-04 11:38:10 +01:00

arm64

arm64: spectre: Prevent lockdep splat on v4 mitigation enable path