tcg/aarch64: Return false on failure from patch_reloc

This does require an extra two checks within the slow paths
to replace the assert that we're moving.
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>

tcg/aarch64/tcg-target.inc.c

@@ -78,20 +78,26 @@ static const int tcg_target_call_oarg_regs[1] = {
 #define TCG_REG_GUEST_BASE TCG_REG_X28
 #endif
 
-static inline void reloc_pc26(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
+static inline bool reloc_pc26(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
 {
     ptrdiff_t offset = target - code_ptr;
-    tcg_debug_assert(offset == sextract64(offset, 0, 26));
-    /* read instruction, mask away previous PC_REL26 parameter contents,
-       set the proper offset, then write back the instruction. */
-    *code_ptr = deposit32(*code_ptr, 0, 26, offset);
+    if (offset == sextract64(offset, 0, 26)) {
+        /* read instruction, mask away previous PC_REL26 parameter contents,
+           set the proper offset, then write back the instruction. */
+        *code_ptr = deposit32(*code_ptr, 0, 26, offset);
+        return true;
+    }
+    return false;
 }
 
-static inline void reloc_pc19(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
+static inline bool reloc_pc19(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
 {
     ptrdiff_t offset = target - code_ptr;
-    tcg_debug_assert(offset == sextract64(offset, 0, 19));
-    *code_ptr = deposit32(*code_ptr, 5, 19, offset);
+    if (offset == sextract64(offset, 0, 19)) {
+        *code_ptr = deposit32(*code_ptr, 5, 19, offset);
+        return true;
+    }
+    return false;
 }
 
 static inline bool patch_reloc(tcg_insn_unit *code_ptr, int type,
@@ -101,15 +107,12 @@ static inline bool patch_reloc(tcg_insn_unit *code_ptr, int type,
     switch (type) {
     case R_AARCH64_JUMP26:
     case R_AARCH64_CALL26:
-        reloc_pc26(code_ptr, (tcg_insn_unit *)value);
-        break;
+        return reloc_pc26(code_ptr, (tcg_insn_unit *)value);
     case R_AARCH64_CONDBR19:
-        reloc_pc19(code_ptr, (tcg_insn_unit *)value);
-        break;
+        return reloc_pc19(code_ptr, (tcg_insn_unit *)value);
     default:
-        tcg_abort();
+        g_assert_not_reached();
     }
-    return true;
 }
 
 #define TCG_CT_CONST_AIMM 0x100
@@ -1387,7 +1390,8 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     TCGMemOp opc = get_memop(oi);
     TCGMemOp size = opc & MO_SIZE;
 
-    reloc_pc19(lb->label_ptr[0], s->code_ptr);
+    bool ok = reloc_pc19(lb->label_ptr[0], s->code_ptr);
+    tcg_debug_assert(ok);
 
     tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_X0, TCG_AREG0);
     tcg_out_mov(s, TARGET_LONG_BITS == 64, TCG_REG_X1, lb->addrlo_reg);
@@ -1409,7 +1413,8 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     TCGMemOp opc = get_memop(oi);
     TCGMemOp size = opc & MO_SIZE;
 
-    reloc_pc19(lb->label_ptr[0], s->code_ptr);
+    bool ok = reloc_pc19(lb->label_ptr[0], s->code_ptr);
+    tcg_debug_assert(ok);
 
     tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_X0, TCG_AREG0);
     tcg_out_mov(s, TARGET_LONG_BITS == 64, TCG_REG_X1, lb->addrlo_reg);