| Message ID | 20220416015018.2025282-1-jcmvbkbc@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xtensa: fix a7 clobbering in coprocessor context load/store | expand |
diff --git a/arch/xtensa/kernel/coprocessor.S b/arch/xtensa/kernel/coprocessor.S index 45cc0ae0af6f..c7b9f12896f2 100644 --- 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
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> --- arch/xtensa/kernel/coprocessor.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)