Simplify TCG relocation bugfix.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3974 c046a42c-6fe2-441c-8c8c-71466251a162

5 files changed, 12 insertions, 17 deletions

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index dd8b5f6..ceacb4f 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -318,7 +318,7 @@ static void tcg_out_jxx(TCGContext *s, int opc, int label_index)
             tcg_out8(s, 0x80 + opc);
         }
         tcg_out_reloc(s, s->code_ptr, R_386_PC32, label_index, -4);
-        tcg_out32(s, -4);
+        s->code_ptr += 4;
     }
 }
 
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 4ddc62f..a206e53 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -97,9 +97,9 @@ void tcg_out_reloc(TCGContext *s, uint8_t *code_ptr, int type,
 
     l = &s->labels[label_index];
     if (l->has_value) {
-        /* FIXME: This is wrong.  We can not resolve the relocation
-           immediately because the caller has not yet written the
-           initial value.  */
+        /* FIXME: This may break relocations on RISC targets that
+           modify instruction fields in place.  The caller may not have 
+           written the initial value.  */
         patch_reloc(code_ptr, type, l->u.value + addend);
     } else {
         /* add a new relocation entry */
@@ -1810,16 +1810,11 @@ int dyngen_code(TCGContext *s, uint8_t *gen_code_buf)
     return s->code_ptr -  gen_code_buf;
 }
 
-static uint8_t *dummy_code_buf;
-
 /* Return the index of the micro operation such as the pc after is <
-   offset bytes from the start of the TB.
-   We have to use a dummy code buffer here to avoid clobbering the
-   oringinal code.  Because we terminate code generation part way through
-   we can end up with unresolved relocations.  Return -1 if not found. */
-int dyngen_code_search_pc(TCGContext *s, long offset)
+   offset bytes from the start of the TB.  The contents of gen_code_buf must
+   not be changed, though writing the same values is ok.
+   Return -1 if not found. */
+int dyngen_code_search_pc(TCGContext *s, uint8_t *gen_code_buf, long offset)
 {
-    if (!dummy_code_buf)
-        dummy_code_buf = qemu_malloc(code_gen_max_block_size());
-    return tcg_gen_code_common(s, dummy_code_buf, offset);
+    return tcg_gen_code_common(s, gen_code_buf, offset);
 }
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 11ffb0c..09fb9ef 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -257,7 +257,7 @@ void tcg_context_init(TCGContext *s);
 void tcg_func_start(TCGContext *s);
 
 int dyngen_code(TCGContext *s, uint8_t *gen_code_buf);
-int dyngen_code_search_pc(TCGContext *s, long offset);
+int dyngen_code_search_pc(TCGContext *s, uint8_t *gen_code_buf, long offset);
 
 void tcg_set_frame(TCGContext *s, int reg,
                    tcg_target_long start, tcg_target_long size);
diff --git a/tcg/x86_64/tcg-target.c b/tcg/x86_64/tcg-target.c
index b4b3e7d..0ee7d23 100644
--- a/tcg/x86_64/tcg-target.c
+++ b/tcg/x86_64/tcg-target.c
@@ -431,7 +431,7 @@ static void tcg_out_jxx(TCGContext *s, int opc, int label_index)
             tcg_out8(s, 0x80 + opc);
         }
         tcg_out_reloc(s, s->code_ptr, R_386_PC32, label_index, -4);
-        tcg_out32(s, -4);
+        s->code_ptr += 4;
     }
 }
 
diff --git a/translate-all.c b/translate-all.c
index 2000083..f100a98 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -187,7 +187,7 @@ int cpu_restore_state(TranslationBlock *tb,
     s->tb_jmp_offset = NULL;
     s->tb_next = tb->tb_next;
 #endif
-    j = dyngen_code_search_pc(s, searched_pc - tc_ptr);
+    j = dyngen_code_search_pc(s, (uint8_t *)tc_ptr, searched_pc - tc_ptr);
     if (j < 0)
         return -1;
     /* now find start of instruction before */