powerpc: Implement emulation of string loads and stores

The size field of the op.type word is now the total number of bytes
to be loaded or stored.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 209a506f8517e2f49cad323ac301c8b117f549d3..54651fc2d4124dc7fd9b80fa5fbc3d551e7b8f06 100644 (file)
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1433,11 +1433,24 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
                        break;
 
 #endif
+               case 533:       /* lswx */
+                       op->type = MKOP(LOAD_MULTI, 0, regs->xer & 0x7f);
+                       break;
 
                case 534:       /* lwbrx */
                        op->type = MKOP(LOAD, BYTEREV, 4);
                        break;
 
+               case 597:       /* lswi */
+                       if (rb == 0)
+                               rb = 32;        /* # bytes to load */
+                       op->type = MKOP(LOAD_MULTI, 0, rb);
+                       op->ea = 0;
+                       if (ra)
+                               op->ea = truncate_if_32bit(regs->msr,
+                                                          regs->gpr[ra]);
+                       break;
+
 #ifdef CONFIG_PPC_FPU
                case 535:       /* lfsx */
                case 567:       /* lfsux */
@@ -1475,11 +1488,25 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
                        break;
 
 #endif
+               case 661:       /* stswx */
+                       op->type = MKOP(STORE_MULTI, 0, regs->xer & 0x7f);
+                       break;
+
                case 662:       /* stwbrx */
                        op->type = MKOP(STORE, BYTEREV, 4);
                        op->val = byterev_4(regs->gpr[rd]);
                        break;
 
+               case 725:
+                       if (rb == 0)
+                               rb = 32;        /* # bytes to store */
+                       op->type = MKOP(STORE_MULTI, 0, rb);
+                       op->ea = 0;
+                       if (ra)
+                               op->ea = truncate_if_32bit(regs->msr,
+                                                          regs->gpr[ra]);
+                       break;
+
                case 790:       /* lhbrx */
                        op->type = MKOP(LOAD, BYTEREV, 2);
                        break;
@@ -1553,15 +1580,14 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
                break;
 
        case 46:        /* lmw */
-               ra = (instr >> 16) & 0x1f;
                if (ra >= rd)
                        break;          /* invalid form, ra in range to load */
-               op->type = MKOP(LOAD_MULTI, 0, 4);
+               op->type = MKOP(LOAD_MULTI, 0, 4 * (32 - rd));
                op->ea = dform_ea(instr, regs);
                break;
 
        case 47:        /* stmw */
-               op->type = MKOP(STORE_MULTI, 0, 4);
+               op->type = MKOP(STORE_MULTI, 0, 4 * (32 - rd));
                op->ea = dform_ea(instr, regs);
                break;
 
@@ -1744,7 +1770,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
        int r, err, size;
        unsigned long val;
        unsigned int cr;
-       int rd;
+       int i, rd, nb;
 
        r = analyse_instr(&op, regs, instr);
        if (r != 0)
@@ -1866,12 +1892,18 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
                if (regs->msr & MSR_LE)
                        return 0;
                rd = op.reg;
-               do {
-                       err = read_mem(&regs->gpr[rd], op.ea, 4, regs);
+               for (i = 0; i < size; i += 4) {
+                       nb = size - i;
+                       if (nb > 4)
+                               nb = 4;
+                       err = read_mem(&regs->gpr[rd], op.ea, nb, regs);
                        if (err)
                                return 0;
+                       if (nb < 4)     /* left-justify last bytes */
+                               regs->gpr[rd] <<= 32 - 8 * nb;
                        op.ea += 4;
-               } while (++rd < 32);
+                       ++rd;
+               }
                goto instr_done;
 
        case STORE:
@@ -1914,12 +1946,19 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
                if (regs->msr & MSR_LE)
                        return 0;
                rd = op.reg;
-               do {
-                       err = write_mem(regs->gpr[rd], op.ea, 4, regs);
+               for (i = 0; i < size; i += 4) {
+                       val = regs->gpr[rd];
+                       nb = size - i;
+                       if (nb > 4)
+                               nb = 4;
+                       else
+                               val >>= 32 - 8 * nb;
+                       err = write_mem(val, op.ea, nb, regs);
                        if (err)
                                return 0;
                        op.ea += 4;
-               } while (++rd < 32);
+                       ++rd;
+               }
                goto instr_done;
 
        case MFMSR: