Merge branch 'x86/debug' into core/urgent

[sfrench/cifs-2.6.git] / tools / objtool / check.c

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index de8f40730b376dd381cc8229ddfaef75e5a15852..2f8ba036823109d32ccb3f0f4973c7b742a8c897 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -18,6 +18,8 @@
 
 #define FAKE_JUMP_OFFSET -1
 
+#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
+
 struct alternative {
        struct list_head list;
        struct instruction *insn;
@@ -1035,9 +1037,15 @@ static struct rela *find_switch_table(struct objtool_file *file,
 
                /*
                 * Make sure the .rodata address isn't associated with a
-                * symbol.  gcc jump tables are anonymous data.
+                * symbol.  GCC jump tables are anonymous data.
+                *
+                * Also support C jump tables which are in the same format as
+                * switch jump tables.  For objtool to recognize them, they
+                * need to be placed in the C_JUMP_TABLE_SECTION section.  They
+                * have symbols associated with them.
                 */
-               if (find_symbol_containing(rodata_sec, table_offset))
+               if (find_symbol_containing(rodata_sec, table_offset) &&
+                   strcmp(rodata_sec->name, C_JUMP_TABLE_SECTION))
                        continue;
 
                rodata_rela = find_rela_by_dest(rodata_sec, table_offset);
@@ -1277,13 +1285,18 @@ static void mark_rodata(struct objtool_file *file)
        bool found = false;
 
        /*
-        * This searches for the .rodata section or multiple .rodata.func_name
-        * sections if -fdata-sections is being used. The .str.1.1 and .str.1.8
-        * rodata sections are ignored as they don't contain jump tables.
+        * Search for the following rodata sections, each of which can
+        * potentially contain jump tables:
+        *
+        * - .rodata: can contain GCC switch tables
+        * - .rodata.<func>: same, if -fdata-sections is being used
+        * - .rodata..c_jump_table: contains C annotated jump tables
+        *
+        * .rodata.str1.* sections are ignored; they don't contain jump tables.
         */
        for_each_sec(file, sec) {
-               if (!strncmp(sec->name, ".rodata", 7) &&
-                   !strstr(sec->name, ".str1.")) {
+               if ((!strncmp(sec->name, ".rodata", 7) && !strstr(sec->name, ".str1.")) ||
+                   !strcmp(sec->name, C_JUMP_TABLE_SECTION)) {
                        sec->rodata = true;
                        found = true;
                }