[PATCH 1/2] powerpc/sstep: Fix issues with set_cr0()

[PATCH 1/2] powerpc/sstep: Fix issues with set_cr0()

[Anton Blanchard]

From: Anton Blanchard <anton@samba.org>

set_cr0() broke when we changed analyse_instr() to not modify the
register state. Instead of looking at regs->gpr[x] which has not
been updated yet, we need to look at op->val.

Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Anton Blanchard <anton@samba.org>
---
 arch/powerpc/lib/sstep.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index fb9f58b868e7..9d72e5900320 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -944,9 +944,9 @@ NOKPROBE_SYMBOL(emulate_dcbz);
 		: "r" (addr), "i" (-EFAULT), "0" (err))
 
 static nokprobe_inline void set_cr0(const struct pt_regs *regs,
-				    struct instruction_op *op, int rd)
+				    struct instruction_op *op)
 {
-	long val = regs->gpr[rd];
+	long val = op->val;
 
 	op->type |= SETCC;
 	op->ccval = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
@@ -1326,7 +1326,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 	case 13:	/* addic. */
 		imm = (short) instr;
 		add_with_carry(regs, op, rd, regs->gpr[ra], imm, 0);
-		set_cr0(regs, op, rd);
+		set_cr0(regs, op);
 		return 1;
 
 	case 14:	/* addi */
@@ -1397,13 +1397,13 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 	case 28:	/* andi. */
 		op->val = regs->gpr[rd] & (unsigned short) instr;
-		set_cr0(regs, op, ra);
+		set_cr0(regs, op);
 		goto logical_done_nocc;
 
 	case 29:	/* andis. */
 		imm = (unsigned short) instr;
 		op->val = regs->gpr[rd] & (imm << 16);
-		set_cr0(regs, op, ra);
+		set_cr0(regs, op);
 		goto logical_done_nocc;
 
 #ifdef __powerpc64__
@@ -2526,7 +2526,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
  logical_done:
 	if (instr & 1)
-		set_cr0(regs, op, ra);
+		set_cr0(regs, op);
  logical_done_nocc:
 	op->reg = ra;
 	op->type |= SETREG;
@@ -2534,7 +2534,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
  arith_done:
 	if (instr & 1)
-		set_cr0(regs, op, rd);
+		set_cr0(regs, op);
  compute_done:
 	op->reg = rd;
 	op->type |= SETREG;
-- 
2.11.0

[PATCH 2/2] powerpc/sstep: Fix issues with mcrf

[Anton Blanchard]

From: Anton Blanchard <anton@samba.org>

mcrf broke when we changed analyse_instr() to not modify the register
state. The instruction writes to the CR, so we need to store the result
in op->ccval, not op->val.

Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Anton Blanchard <anton@samba.org>
---
 arch/powerpc/lib/sstep.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 9d72e5900320..c4cda1afb49d 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1513,10 +1513,10 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			op->type = COMPUTE + SETCC;
 			imm = 0xf0000000UL;
 			val = regs->gpr[rd];
-			op->val = regs->ccr;
+			op->ccval = regs->ccr;
 			for (sh = 0; sh < 8; ++sh) {
 				if (instr & (0x80000 >> sh))
-					op->val = (op->val & ~imm) |
+					op->ccval = (op->ccval & ~imm) |
 						(val & imm);
 				imm >>= 4;
 			}
-- 
2.11.0

Re: [1/2] powerpc/sstep: Fix issues with set_cr0()

[Michael Ellerman]

On Tue, 2017-09-19 at 10:45:52 UTC, Anton Blanchard wrote:
> From: Anton Blanchard <anton@samba.org>
> 
> set_cr0() broke when we changed analyse_instr() to not modify the
> register state. Instead of looking at regs->gpr[x] which has not
> been updated yet, we need to look at op->val.
> 
> Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs")
> Signed-off-by: Anton Blanchard <anton@samba.org>

Series applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/ad47ff3e33503e0969db2d4f9a4094

cheers