R_PPC_REL24 safety net

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4706 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 8 insertions, 0 deletions

diff --git a/dyngen.c b/dyngen.c
index c38d12386f..880d641a56 100644
--- a/dyngen.c
+++ b/dyngen.c
@@ -1963,6 +1963,14 @@ void gen_code(const char *name, host_ulong offset, host_ulong size,
                                 break;
                             case R_PPC_REL24:
                                 /* warning: must be at 32 MB distancy */
+                                fprintf(outfile, "{\n"
+                                        "    long disp = (%s - (long)(gen_code_ptr + %d) + %d);\n"
+                                        "    if ((disp << 6) >> 6 != disp) {;\n"
+                                        "        fprintf(stderr, \"Branch target is too far away\\n\");"
+                                        "        abort();\n"
+                                        "    }\n"
+                                        "}\n",
+                                        relname, reloc_offset, addend);
                                 fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | ((%s - (long)(gen_code_ptr + %d) + %d) & 0x03fffffc);\n",
                                         reloc_offset, reloc_offset, relname, reloc_offset, addend);
                                 break;