powerpc/kprobes: Don't save/restore DAR/DSISR to/from pt_regs for optprobes
authorNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Thu, 8 Jun 2017 19:16:55 +0000 (00:46 +0530)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 24 Aug 2017 06:19:01 +0000 (16:19 +1000)
We don't save/restore these across a trap, or with KPROBES_ON_FTRACE.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/kernel/optprobes_head.S

index 4937bef7652f4bc3dd1837be993d5d117917664c..52fc864cdec4e9f3950fc5da1a48de74a34380d7 100644 (file)
@@ -60,10 +60,6 @@ optprobe_template_entry:
        std     r5,_CCR(r1)
        lbz     r5,PACASOFTIRQEN(r13)
        std     r5,SOFTE(r1)
-       mfdar   r5
-       std     r5,_DAR(r1)
-       mfdsisr r5
-       std     r5,_DSISR(r1)
 
        /*
         * We may get here from a module, so load the kernel TOC in r2.
@@ -122,10 +118,6 @@ optprobe_template_call_emulate:
        mtxer   r5
        ld      r5,_CCR(r1)
        mtcr    r5
-       ld      r5,_DAR(r1)
-       mtdar   r5
-       ld      r5,_DSISR(r1)
-       mtdsisr r5
        REST_GPR(0,r1)
        REST_10GPRS(2,r1)
        REST_10GPRS(12,r1)