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| author | Nicholas Piggin <npiggin@gmail.com> | 2022-11-27 22:49:30 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-12-02 17:54:07 +1100 |
| commit | baa49d81a94bb4170e7f2f4d97016772117d0f60 (patch) | |
| tree | e2088da77c790d6806d9c569c5dfcb2592702967 | |
| parent | bc0677363d0ffaec0c56685291e97b080116976c (diff) | |
| download | lwn-baa49d81a94bb4170e7f2f4d97016772117d0f60.tar.gz lwn-baa49d81a94bb4170e7f2f4d97016772117d0f60.zip | |
powerpc/pseries: hvcall stack frame overhead
This call may use the min size stack frame. The scratch space used is
in the caller's parameter area frame, not this function's frame.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-6-npiggin@gmail.com
| -rw-r--r-- | arch/powerpc/platforms/pseries/hvCall.S | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S index 762eb15d3bd4..783c16ad648b 100644 --- a/arch/powerpc/platforms/pseries/hvCall.S +++ b/arch/powerpc/platforms/pseries/hvCall.S @@ -27,7 +27,9 @@ hcall_tracepoint_refcount: /* * precall must preserve all registers. use unused STK_PARAM() - * areas to save snapshots and opcode. + * areas to save snapshots and opcode. STK_PARAM() in the caller's + * frame will be available even on ELFv2 because these are all + * variadic functions. */ #define HCALL_INST_PRECALL(FIRST_REG) \ mflr r0; \ @@ -41,29 +43,29 @@ hcall_tracepoint_refcount: std r10,STK_PARAM(R10)(r1); \ std r0,16(r1); \ addi r4,r1,STK_PARAM(FIRST_REG); \ - stdu r1,-STACK_FRAME_OVERHEAD(r1); \ + stdu r1,-STACK_FRAME_MIN_SIZE(r1); \ bl __trace_hcall_entry; \ - ld r3,STACK_FRAME_OVERHEAD+STK_PARAM(R3)(r1); \ - ld r4,STACK_FRAME_OVERHEAD+STK_PARAM(R4)(r1); \ - ld r5,STACK_FRAME_OVERHEAD+STK_PARAM(R5)(r1); \ - ld r6,STACK_FRAME_OVERHEAD+STK_PARAM(R6)(r1); \ - ld r7,STACK_FRAME_OVERHEAD+STK_PARAM(R7)(r1); \ - ld r8,STACK_FRAME_OVERHEAD+STK_PARAM(R8)(r1); \ - ld r9,STACK_FRAME_OVERHEAD+STK_PARAM(R9)(r1); \ - ld r10,STACK_FRAME_OVERHEAD+STK_PARAM(R10)(r1) + ld r3,STACK_FRAME_MIN_SIZE+STK_PARAM(R3)(r1); \ + ld r4,STACK_FRAME_MIN_SIZE+STK_PARAM(R4)(r1); \ + ld r5,STACK_FRAME_MIN_SIZE+STK_PARAM(R5)(r1); \ + ld r6,STACK_FRAME_MIN_SIZE+STK_PARAM(R6)(r1); \ + ld r7,STACK_FRAME_MIN_SIZE+STK_PARAM(R7)(r1); \ + ld r8,STACK_FRAME_MIN_SIZE+STK_PARAM(R8)(r1); \ + ld r9,STACK_FRAME_MIN_SIZE+STK_PARAM(R9)(r1); \ + ld r10,STACK_FRAME_MIN_SIZE+STK_PARAM(R10)(r1) /* * postcall is performed immediately before function return which * allows liberal use of volatile registers. */ #define __HCALL_INST_POSTCALL \ - ld r0,STACK_FRAME_OVERHEAD+STK_PARAM(R3)(r1); \ - std r3,STACK_FRAME_OVERHEAD+STK_PARAM(R3)(r1); \ + ld r0,STACK_FRAME_MIN_SIZE+STK_PARAM(R3)(r1); \ + std r3,STACK_FRAME_MIN_SIZE+STK_PARAM(R3)(r1); \ mr r4,r3; \ mr r3,r0; \ bl __trace_hcall_exit; \ - ld r0,STACK_FRAME_OVERHEAD+16(r1); \ - addi r1,r1,STACK_FRAME_OVERHEAD; \ + ld r0,STACK_FRAME_MIN_SIZE+16(r1); \ + addi r1,r1,STACK_FRAME_MIN_SIZE; \ ld r3,STK_PARAM(R3)(r1); \ mtlr r0 @@ -303,14 +305,14 @@ plpar_hcall9_trace: mr r7,r8 mr r8,r9 mr r9,r10 - ld r10,STACK_FRAME_OVERHEAD+STK_PARAM(R11)(r1) - ld r11,STACK_FRAME_OVERHEAD+STK_PARAM(R12)(r1) - ld r12,STACK_FRAME_OVERHEAD+STK_PARAM(R13)(r1) + ld r10,STACK_FRAME_MIN_SIZE+STK_PARAM(R11)(r1) + ld r11,STACK_FRAME_MIN_SIZE+STK_PARAM(R12)(r1) + ld r12,STACK_FRAME_MIN_SIZE+STK_PARAM(R13)(r1) HVSC mr r0,r12 - ld r12,STACK_FRAME_OVERHEAD+STK_PARAM(R4)(r1) + ld r12,STACK_FRAME_MIN_SIZE+STK_PARAM(R4)(r1) std r4,0(r12) std r5,8(r12) std r6,16(r12) |