...

4 files changed, 129 insertions, 97 deletions

diff --git a/lib/arm/assemble.h b/lib/arm/assemble.h
new file mode 100644
index 0000000..90f91c9
--- /dev/null
+++ b/lib/arm/assemble.h
@@ -0,0 +1,80 @@
+#pragma once
+#include "dis.h"
+
+static inline void PUSHone(void **codep, int Rt) {
+    if (codep->arch.pc_low_bit)
+        op32(codep, 0x0d04f84d | Rt << 28);
+    else
+        op32(codep, 0xe52d0004 | Rt << 12);
+}
+
+static inline void POPone(void **codep, int Rt) {
+    if (codep->arch.pc_low_bit)
+        op32(codep, 0x0b04f85d | Rt << 28);
+    else
+        op32(codep, 0xe49d0004 | Rt << 12);
+}
+
+static inline void POPmulti(void **codep, uint16_t mask) {
+    if (codep->arch.pc_low_bit)
+        op32(codep, 0x0000e8bd | mask << 16);
+    else
+        op32(codep, 0xe8bd0000 | mask);
+}
+
+static inline void MOVW_MOVT(void **codep, int Rd, uint32_t val) {
+    uint16_t hi = val >> 16, lo = (uint16_t) val;
+    if (codep->arch.pc_low_bit) {
+        op32(codep, 0x0000f240 | Rd << 24 | lo >> 12 | (lo >> 11 & 1) << 10 |
+                                 (lo >> 8 & 7) << 28 | (lo & 0xff) << 16);
+        op32(codep, 0x0000f2c0 | Rd << 24 | hi >> 12 | (hi >> 11 & 1) << 10 |
+                                 (hi >> 8 & 7) << 28 | (hi & 0xff) << 16);
+
+    } else {
+        op32(codep, 0xe3000000 | Rd << 12 | (lo >> 12) << 16 | (lo & 0xfff));
+        op32(codep, 0xe3400000 | Rd << 12 | (hi >> 12) << 16 | (hi & 0xfff));
+    }
+
+}
+
+static inline void STRri(void **codep, int Rt, int Rn, uint32_t off) {
+    if (codep->arch.pc_low_bit)
+        op32(codep, 0x0000f8c0 | Rn | Rt << 28 | off << 16);
+    else
+        op32(codep, 0xe4800000 | Rn << 16 | Rt << 12 | off);
+}
+
+static inline void LDRxi(void **codep, int Rt, int Rn, uint32_t off,
+                         enum pcrel_load_mode load_mode) {
+    if (codep->arch.pc_low_bit) {
+        int subop, sign;
+        switch (load_mode) {
+            case PLM_U8:  subop = 0; sign = 0; break;
+            case PLM_S8:  subop = 0; sign = 1; break;
+            case PLM_U16: subop = 1; sign = 0; break;
+            case PLM_S16: subop = 1; sign = 1; break;
+            case PLM_U32: subop = 2; sign = 0; break;
+            default: __builtin_abort();
+        }
+        op32(codep, 0x0000f890 | Rn | Rt << 28 | subop << 5 | sign << 8 | off << 16);
+    } else {
+        int is_byte, subop, not_ldrd;
+        switch (load_mode) {
+            case PLM_U8:   is_byte = 1; goto type1;
+            case PLM_S8:   subop = 13; not_ldrd = 1; goto type2;
+            case PLM_U16:  subop = 11; not_ldrd = 1; goto type2;
+            case PLM_S16:  subop = 15; not_ldrd = 1; goto type2;
+            case PLM_U32:  is_byte = 0; goto type1;
+            case PLM_U128: subop = 13; not_ldrd = 0; goto type2;
+            type1:
+                op32(codep, 0xe5900000 | Rn << 16 | Rt << 12 | off);
+                break;
+            type2:
+                op32(codep, 0xe1c00000 | Rn << 16 | Rt << 12 | subop << 4 |
+                            (off & 0xf) | (off & 0xf0) << 4 | not_ldrd << 20);
+                break;
+            default:
+                __builtin_abort();
+        }
+    }
+}
diff --git a/lib/arm/jump-patch.h b/lib/arm/jump-patch.h
new file mode 100644
index 0000000..b19e90f
--- /dev/null
+++ b/lib/arm/jump-patch.h
@@ -0,0 +1,18 @@
+#pragma once
+#include "dis.h"
+#define MAX_JUMP_PATCH_SIZE 8
+#define MAX_REWRITTEN_SIZE (12 * 4) /* actually should be less */
+
+static inline int jump_patch_size(uintptr_t pc, uintptr_t dpc,
+                                  struct arch_dis_ctx arch) {
+    return 8;
+}
+
+static inline void make_jump_patch(void **codep, uintptr_t pc, uintptr_t dpc,
+                                   struct arch_dis_ctx arch) {
+    if (arch.pc_low_bit)
+        op32(codep, 0xf000f8df);
+    else
+        op32(codep, 0xe51ff004);
+    op32(codep, (uint32_t) pc);
+}
diff --git a/lib/arm/misc.h b/lib/arm/misc.h
index 047be2d..3dc9633 100644
--- a/lib/arm/misc.h
+++ b/lib/arm/misc.h
@@ -1,6 +1,7 @@
 #pragma once
 #define TARGET_DIS_SUPPORTED
 #define TARGET_DIS_HEADER "arm/dis-arm-multi.inc.h"
+#define TARGET_JUMP_PATCH_HDR "arm/jump-patch.h"
 #define TARGET_TRANSFORM_DIS_HEADER "arm/transform-dis-arm-multi.inc.h"
 #define MIN_INSN_SIZE 2
 struct arch_dis_ctx {
@@ -8,3 +9,9 @@ struct arch_dis_ctx {
     bool pc_low_bit;
 };
 enum { IS_LDRD_STRD = 1 << 16 };
+
+#define JUMP_PATCH_SIZE 8
+#define MAX_REWRITTEN_SIZE (12 * 4) /* actually should be less */
+static inline bool can_reach_with_jump_patch(uintptr_t pc, uintptr_t dpc) {
+    return true;
+}
diff --git a/lib/arm/transform-dis-arm-multi.inc.h b/lib/arm/transform-dis-arm-multi.inc.h
index f1b9b80..001e613 100644
--- a/lib/arm/transform-dis-arm-multi.inc.h
+++ b/lib/arm/transform-dis-arm-multi.inc.h
@@ -1,80 +1,4 @@
-static inline void PUSHone(struct transform_dis_ctx *ctx, int Rt) {
-    if (ctx->arch.pc_low_bit)
-        op32(ctx, 0x0d04f84d | Rt << 28);
-    else
-        op32(ctx, 0xe52d0004 | Rt << 12);
-}
-
-static inline void POPone(struct transform_dis_ctx *ctx, int Rt) {
-    if (ctx->arch.pc_low_bit)
-        op32(ctx, 0x0b04f85d | Rt << 28);
-    else
-        op32(ctx, 0xe49d0004 | Rt << 12);
-}
-
-static inline void POPmulti(struct transform_dis_ctx *ctx, uint16_t mask) {
-    if (ctx->arch.pc_low_bit)
-        op32(ctx, 0x0000e8bd | mask << 16);
-    else
-        op32(ctx, 0xe8bd0000 | mask);
-}
-
-static inline void MOVW_MOVT(struct transform_dis_ctx *ctx, int Rd, uint32_t val) {
-    uint16_t hi = val >> 16, lo = (uint16_t) val;
-    if (ctx->arch.pc_low_bit) {
-        op32(ctx, 0x0000f240 | Rd << 24 | lo >> 12 | (lo >> 11 & 1) << 10 |
-                               (lo >> 8 & 7) << 28 | (lo & 0xff) << 16);
-        op32(ctx, 0x0000f2c0 | Rd << 24 | hi >> 12 | (hi >> 11 & 1) << 10 |
-                               (hi >> 8 & 7) << 28 | (hi & 0xff) << 16);
-
-    } else {
-        op32(ctx, 0xe3000000 | Rd << 12 | (lo >> 12) << 16 | (lo & 0xfff));
-        op32(ctx, 0xe3400000 | Rd << 12 | (hi >> 12) << 16 | (hi & 0xfff));
-    }
-
-}
-
-static inline void STRri(struct transform_dis_ctx *ctx, int Rt, int Rn, uint32_t off) {
-    if (ctx->arch.pc_low_bit)
-        op32(ctx, 0x0000f8c0 | Rn | Rt << 28 | off << 16);
-    else
-        op32(ctx, 0xe4800000 | Rn << 16 | Rt << 12 | off);
-}
-
-static inline void LDRxi(struct transform_dis_ctx *ctx, int Rt, int Rn, uint32_t off,
-                         enum pcrel_load_mode load_mode) {
-    if (ctx->arch.pc_low_bit) {
-        int subop, sign;
-        switch (load_mode) {
-            case PLM_U8:  subop = 0; sign = 0; break;
-            case PLM_S8:  subop = 0; sign = 1; break;
-            case PLM_U16: subop = 1; sign = 0; break;
-            case PLM_S16: subop = 1; sign = 1; break;
-            case PLM_U32: subop = 2; sign = 0; break;
-            default: __builtin_abort();
-        }
-        op32(ctx, 0x0000f890 | Rn | Rt << 28 | subop << 5 | sign << 8 | off << 16);
-    } else {
-        int is_byte, subop, not_ldrd;
-        switch (load_mode) {
-            case PLM_U8:   is_byte = 1; goto type1;
-            case PLM_S8:   subop = 13; not_ldrd = 1; goto type2;
-            case PLM_U16:  subop = 11; not_ldrd = 1; goto type2;
-            case PLM_S16:  subop = 15; not_ldrd = 1; goto type2;
-            case PLM_U32:  is_byte = 0; goto type1;
-            case PLM_U128: subop = 13; not_ldrd = 0; goto type2;
-            type1:
-                op32(ctx, 0xe5900000 | Rn << 16 | Rt << 12 | off);
-                break;
-            type2:
-                op32(ctx, 0xe1c00000 | Rn << 16 | Rt << 12 | subop << 4 |
-                     (off & 0xf) | (off & 0xf0) << 4 | not_ldrd << 20);
-                 break;
-            default:
-                __builtin_abort();
-        }
-    }
-}
+#include "arm/assemble.h"
 
 static NOINLINE UNUSED void transform_dis_data(struct transform_dis_ctx *ctx,
         unsigned o0, unsigned o1, unsigned o2, unsigned o3, unsigned out_mask) {
@@ -91,7 +15,7 @@ static NOINLINE UNUSED void transform_dis_data(struct transform_dis_ctx *ctx,
     newval[2] = o2;
     newval[3] = o3;
 
-    void **rpp = ctx->rewritten_ptr_ptr;
+    void **codep = ctx->rewritten_ptr_ptr;
 
     /* A few cases:
      * 1. Move to PC that does not read PC.  Probably fine.
@@ -130,32 +54,33 @@ static NOINLINE UNUSED void transform_dis_data(struct transform_dis_ctx *ctx,
         if (in_regs & 1 << 15)
             return; /* case 1 */
         /* case 2 */
-        PUSHone(ctx, scratch);
-        PUSHone(ctx, scratch);
-        MOVW_MOVT(ctx, scratch, pc);
+        PUSHone(codep, scratch);
+        PUSHone(codep, scratch);
+        MOVW_MOVT(codep, scratch, pc);
         for (int i = 0; i < 4; i++)
             if (newval[i] == 15)
                 newval[i] = scratch;
-        ctx->write_newop_here = *rpp; *rpp += ctx->op_size;
-        STRri(ctx, scratch, 13, 4);
-        POPmulti(ctx, 1 << scratch | 1 << 15);
+        ctx->write_newop_here = *codep; *codep += ctx->op_size;
+        STRri(codep, scratch, 13, 4);
+        POPmulti(codep, 1 << scratch | 1 << 15);
+        transform_dis_ret(ctx);
     } else {
         if (out_reg != -1 && !(in_regs & 1 << out_reg)) {
             /* case 3 - ignore scratch */
-            MOVW_MOVT(ctx, out_reg, pc);
+            MOVW_MOVT(codep, out_reg, pc);
             for (int i = 0; i < 4; i++)
                 if (newval[i] == 15)
                     newval[i] = out_reg;
-            ctx->write_newop_here = *rpp; *rpp += ctx->op_size;
+            ctx->write_newop_here = *codep; *codep += ctx->op_size;
         } else {
             /* case 4 */
-            PUSHone(ctx, scratch);
-            MOVW_MOVT(ctx, scratch, pc);
+            PUSHone(codep, scratch);
+            MOVW_MOVT(codep, scratch, pc);
             for (int i = 0; i < 4; i++)
                 if (newval[i] == 15)
                     newval[i] = scratch;
             ctx->write_newop_here = *rpp; *rpp += ctx->op_size;
-            POPone(ctx, scratch);
+            POPone(codep, scratch);
         }
     }
     ctx->modify = true;
@@ -172,18 +97,20 @@ static NOINLINE UNUSED void transform_dis_pcrel(struct transform_dis_ctx *ctx,
            (void *) dpc, reg, load_mode);
 #endif
     ctx->write_newop_here = NULL;
+    void **codep = ctx->rewritten_ptr_ptr;
     if (reg == 15) {
         int scratch = 0;
-        PUSHone(ctx, scratch);
-        PUSHone(ctx, scratch);
-        MOVW_MOVT(ctx, scratch, dpc);
+        PUSHone(codep, scratch);
+        PUSHone(codep, scratch);
+        MOVW_MOVT(codep, scratch, dpc);
         if (load_mode != PLM_ADR)
-            LDRxi(ctx, scratch, scratch, 0, load_mode);
-        STRri(ctx, scratch, 13, 4);
-        POPmulti(ctx, 1 << scratch | 1 << 15);
+            LDRxi(codep, scratch, scratch, 0, load_mode);
+        STRri(codep, scratch, 13, 4);
+        POPmulti(codep, 1 << scratch | 1 << 15);
+        transform_dis_ret(codep);
     } else {
-        MOVW_MOVT(ctx, reg, dpc);
+        MOVW_MOVT(codep, reg, dpc);
         if (load_mode != PLM_ADR)
-            LDRxi(ctx, reg, reg, 0, load_mode);
+            LDRxi(codep, reg, reg, 0, load_mode);
     }
 }