| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 59/86] xtensa: fix a7 clobbering in coprocessor context load/store | Date | Tue, 26 Apr 2022 10:21:27 +0200 |
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From: Max Filippov <jcmvbkbc@gmail.com>
commit 839769c35477d4acc2369e45000ca7b0b6af39a7 upstream.
Fast coprocessor exception handler saves a3..a6, but coprocessor context load/store code uses a4..a7 as temporaries, potentially clobbering a7. 'Potentially' because coprocessor state load/store macros may not use all four temporary registers (and neither FPU nor HiFi macros do). Use a3..a6 as intended.
Cc: stable@vger.kernel.org Fixes: c658eac628aa ("[XTENSA] Add support for configurable registers and coprocessors") Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/xtensa/kernel/coprocessor.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/xtensa/kernel/coprocessor.S +++ b/arch/xtensa/kernel/coprocessor.S @@ -29,7 +29,7 @@ .if XTENSA_HAVE_COPROCESSOR(x); \ .align 4; \ .Lsave_cp_regs_cp##x: \ - xchal_cp##x##_store a2 a4 a5 a6 a7; \ + xchal_cp##x##_store a2 a3 a4 a5 a6; \ jx a0; \ .endif @@ -46,7 +46,7 @@ .if XTENSA_HAVE_COPROCESSOR(x); \ .align 4; \ .Lload_cp_regs_cp##x: \ - xchal_cp##x##_load a2 a4 a5 a6 a7; \ + xchal_cp##x##_load a2 a3 a4 a5 a6; \ jx a0; \ .endif
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