From 6888199f7fe5ea496f48bb6de67b9b7f05b8071b Mon Sep 17 00:00:00 2001
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Date: Wed, 18 Apr 2007 15:56:38 +1000
Subject: [PATCH] [POWERPC] Emulate more instructions in software
Emulate a few more instructions in software - especially useful during
singlestepping (xmon/kprobes).
Instructions emulated with this patch are mfcr/mtcr rX, mfxer/mtxer rX,
mflr/mtlr rX, mfctr/mtctr rX and mr rA,rB.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/lib/sstep.c | 45 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 7e8ded051b5b..4aae0c387645 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -54,7 +54,7 @@ static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
*/
int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
{
- unsigned int opcode, rd;
+ unsigned int opcode, rs, rb, rd, spr;
unsigned long int imm;
opcode = instr >> 26;
@@ -152,6 +152,49 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
regs->nip &= 0xffffffffUL;
return 1;
#endif
+ case 0x26: /* mfcr */
+ regs->gpr[rd] = regs->ccr;
+ regs->gpr[rd] &= 0xffffffffUL;
+ goto mtspr_out;
+ case 0x2a6: /* mfspr */
+ spr = (instr >> 11) & 0x3ff;
+ switch (spr) {
+ case 0x20: /* mfxer */
+ regs->gpr[rd] = regs->xer;
+ regs->gpr[rd] &= 0xffffffffUL;
+ goto mtspr_out;
+ case 0x100: /* mflr */
+ regs->gpr[rd] = regs->link;
+ goto mtspr_out;
+ case 0x120: /* mfctr */
+ regs->gpr[rd] = regs->ctr;
+ goto mtspr_out;
+ }
+ break;
+ case 0x378: /* orx */
+ rs = (instr >> 21) & 0x1f;
+ rb = (instr >> 11) & 0x1f;
+ if (rs == rb) { /* mr */
+ rd = (instr >> 16) & 0x1f;
+ regs->gpr[rd] = regs->gpr[rs];
+ goto mtspr_out;
+ }
+ break;
+ case 0x3a6: /* mtspr */
+ spr = (instr >> 11) & 0x3ff;
+ switch (spr) {
+ case 0x20: /* mtxer */
+ regs->xer = (regs->gpr[rd] & 0xffffffffUL);
+ goto mtspr_out;
+ case 0x100: /* mtlr */
+ regs->link = regs->gpr[rd];
+ goto mtspr_out;
+ case 0x120: /* mtctr */
+ regs->ctr = regs->gpr[rd];
+mtspr_out:
+ regs->nip += 4;
+ return 1;
+ }
}
}
return 0;
--
2.20.1