diff options
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 40 | ||||
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 12 |
2 files changed, 9 insertions, 43 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 7ecc0d1855c..6f7eb7e00c7 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1162,39 +1162,17 @@ machine_check_in_rtas: #ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) - stwu r1,-48(r1) - stw r3, 12(r1) - stw r4, 16(r1) - stw r5, 20(r1) - stw r6, 24(r1) - mflr r3 - stw r7, 28(r1) - mfcr r5 - stw r8, 32(r1) - stw r9, 36(r1) - stw r10,40(r1) - stw r3, 44(r1) - stw r5, 8(r1) - subi r3, r3, MCOUNT_INSN_SIZE - .globl mcount_call -mcount_call: - bl ftrace_stub - nop - lwz r6, 8(r1) - lwz r0, 44(r1) - lwz r3, 12(r1) + /* + * It is required that _mcount on PPC32 must preserve the + * link register. But we have r0 to play with. We use r0 + * to push the return address back to the caller of mcount + * into the ctr register, restore the link register and + * then jump back using the ctr register. + */ + mflr r0 mtctr r0 - lwz r4, 16(r1) - mtcr r6 - lwz r5, 20(r1) - lwz r6, 24(r1) - lwz r0, 52(r1) - lwz r7, 28(r1) - lwz r8, 32(r1) + lwz r0, 4(r1) mtlr r0 - lwz r9, 36(r1) - lwz r10,40(r1) - addi r1, r1, 48 bctr _GLOBAL(ftrace_caller) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index e6d52845854..b00982e0d1e 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -888,18 +888,6 @@ _GLOBAL(enter_prom) #ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) - /* Taken from output of objdump from lib64/glibc */ - mflr r3 - stdu r1, -112(r1) - std r3, 128(r1) - subi r3, r3, MCOUNT_INSN_SIZE - .globl mcount_call -mcount_call: - bl ftrace_stub - nop - ld r0, 128(r1) - mtlr r0 - addi r1, r1, 112 blr _GLOBAL(ftrace_caller) |