objtool: Uniquely identify alternative instruction groups

Assign a unique identifier to every alternative instruction group in
order to be able to tell which instructions belong to what
alternative.

[peterz: extracted from a larger patch]
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index cc52da6..4da6bfb 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -752,7 +752,9 @@ static int handle_group_alt(struct objtool_file *file,
                            struct instruction *orig_insn,
                            struct instruction **new_insn)
 {
+       static unsigned int alt_group_next_index = 1;
        struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
+       unsigned int alt_group = alt_group_next_index++;
        unsigned long dest_off;
 
        last_orig_insn = NULL;
@@ -761,7 +763,7 @@ static int handle_group_alt(struct objtool_file *file,
                if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
                        break;
 
-               insn->alt_group = true;
+               insn->alt_group = alt_group;
                last_orig_insn = insn;
        }
 
@@ -795,6 +797,7 @@ static int handle_group_alt(struct objtool_file *file,
        }
 
        last_new_insn = NULL;
+       alt_group = alt_group_next_index++;
        insn = *new_insn;
        sec_for_each_insn_from(file, insn) {
                if (insn->offset >= special_alt->new_off + special_alt->new_len)
@@ -804,6 +807,7 @@ static int handle_group_alt(struct objtool_file *file,
 
                insn->ignore = orig_insn->ignore_alts;
                insn->func = orig_insn->func;
+               insn->alt_group = alt_group;
 
                /*
                 * Since alternative replacement code is copy/pasted by the

diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 12a9660..2428022 100644 (file)
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -30,12 +30,13 @@ struct instruction {
        unsigned int len;
        enum insn_type type;
        unsigned long immediate;
-       bool alt_group, dead_end, ignore, ignore_alts;
+       bool dead_end, ignore, ignore_alts;
        bool hint;
        bool retpoline_safe;
        s8 instr;
        u8 visited;
        u8 ret_offset;
+       int alt_group;
        struct symbol *call_dest;
        struct instruction *jump_dest;
        struct instruction *first_jump_src;