Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / tools / objtool / check.c

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index f40d46e..b00b189 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -138,6 +138,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
                "__reiserfs_panic",
                "lbug_with_loc",
                "fortify_panic",
+               "usercopy_abort",
        };
 
        if (func->bind == STB_WEAK)
@@ -543,18 +544,14 @@ static int add_call_destinations(struct objtool_file *file)
                        dest_off = insn->offset + insn->len + insn->immediate;
                        insn->call_dest = find_symbol_by_offset(insn->sec,
                                                                dest_off);
-                       /*
-                        * FIXME: Thanks to retpolines, it's now considered
-                        * normal for a function to call within itself.  So
-                        * disable this warning for now.
-                        */
-#if 0
-                       if (!insn->call_dest) {
-                               WARN_FUNC("can't find call dest symbol at offset 0x%lx",
-                                         insn->sec, insn->offset, dest_off);
+
+                       if (!insn->call_dest && !insn->ignore) {
+                               WARN_FUNC("unsupported intra-function call",
+                                         insn->sec, insn->offset);
+                               WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.");
                                return -1;
                        }
-#endif
+
                } else if (rela->sym->type == STT_SECTION) {
                        insn->call_dest = find_symbol_by_offset(rela->sym->sec,
                                                                rela->addend+4);
@@ -598,7 +595,7 @@ static int handle_group_alt(struct objtool_file *file,
                            struct instruction *orig_insn,
                            struct instruction **new_insn)
 {
-       struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump;
+       struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
        unsigned long dest_off;
 
        last_orig_insn = NULL;
@@ -614,28 +611,30 @@ static int handle_group_alt(struct objtool_file *file,
                last_orig_insn = insn;
        }
 
-       if (!next_insn_same_sec(file, last_orig_insn)) {
-               WARN("%s: don't know how to handle alternatives at end of section",
-                    special_alt->orig_sec->name);
-               return -1;
-       }
-
-       fake_jump = malloc(sizeof(*fake_jump));
-       if (!fake_jump) {
-               WARN("malloc failed");
-               return -1;
+       if (next_insn_same_sec(file, last_orig_insn)) {
+               fake_jump = malloc(sizeof(*fake_jump));
+               if (!fake_jump) {
+                       WARN("malloc failed");
+                       return -1;
+               }
+               memset(fake_jump, 0, sizeof(*fake_jump));
+               INIT_LIST_HEAD(&fake_jump->alts);
+               clear_insn_state(&fake_jump->state);
+
+               fake_jump->sec = special_alt->new_sec;
+               fake_jump->offset = -1;
+               fake_jump->type = INSN_JUMP_UNCONDITIONAL;
+               fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
+               fake_jump->ignore = true;
        }
-       memset(fake_jump, 0, sizeof(*fake_jump));
-       INIT_LIST_HEAD(&fake_jump->alts);
-       clear_insn_state(&fake_jump->state);
-
-       fake_jump->sec = special_alt->new_sec;
-       fake_jump->offset = -1;
-       fake_jump->type = INSN_JUMP_UNCONDITIONAL;
-       fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
-       fake_jump->ignore = true;
 
        if (!special_alt->new_len) {
+               if (!fake_jump) {
+                       WARN("%s: empty alternative at end of section",
+                            special_alt->orig_sec->name);
+                       return -1;
+               }
+
                *new_insn = fake_jump;
                return 0;
        }
@@ -648,6 +647,8 @@ static int handle_group_alt(struct objtool_file *file,
 
                last_new_insn = insn;
 
+               insn->ignore = orig_insn->ignore_alts;
+
                if (insn->type != INSN_JUMP_CONDITIONAL &&
                    insn->type != INSN_JUMP_UNCONDITIONAL)
                        continue;
@@ -656,8 +657,14 @@ static int handle_group_alt(struct objtool_file *file,
                        continue;
 
                dest_off = insn->offset + insn->len + insn->immediate;
-               if (dest_off == special_alt->new_off + special_alt->new_len)
+               if (dest_off == special_alt->new_off + special_alt->new_len) {
+                       if (!fake_jump) {
+                               WARN("%s: alternative jump to end of section",
+                                    special_alt->orig_sec->name);
+                               return -1;
+                       }
                        insn->jump_dest = fake_jump;
+               }
 
                if (!insn->jump_dest) {
                        WARN_FUNC("can't find alternative jump destination",
@@ -672,7 +679,8 @@ static int handle_group_alt(struct objtool_file *file,
                return -1;
        }
 
-       list_add(&fake_jump->list, &last_new_insn->list);
+       if (fake_jump)
+               list_add(&fake_jump->list, &last_new_insn->list);
 
        return 0;
 }
@@ -729,10 +737,6 @@ static int add_special_section_alts(struct objtool_file *file)
                        goto out;
                }
 
-               /* Ignore retpoline alternatives. */
-               if (orig_insn->ignore_alts)
-                       continue;
-
                new_insn = NULL;
                if (!special_alt->group || special_alt->new_len) {
                        new_insn = find_insn(file, special_alt->new_sec,
@@ -1089,11 +1093,11 @@ static int decode_sections(struct objtool_file *file)
        if (ret)
                return ret;
 
-       ret = add_call_destinations(file);
+       ret = add_special_section_alts(file);
        if (ret)
                return ret;
 
-       ret = add_special_section_alts(file);
+       ret = add_call_destinations(file);
        if (ret)
                return ret;
 
@@ -1720,10 +1724,12 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
 
                insn->visited = true;
 
-               list_for_each_entry(alt, &insn->alts, list) {
-                       ret = validate_branch(file, alt->insn, state);
-                       if (ret)
-                               return 1;
+               if (!insn->ignore_alts) {
+                       list_for_each_entry(alt, &insn->alts, list) {
+                               ret = validate_branch(file, alt->insn, state);
+                               if (ret)
+                                       return 1;
+                       }
                }
 
                switch (insn->type) {