objtool: Add STT_NOTYPE noinstr validation

Make sure to also check STT_NOTYPE symbols for noinstr violations.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115119.465335884@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index f49bf83..0d9f9cf 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -229,10 +229,18 @@ static void init_cfi_state(struct cfi_state *cfi)
        cfi->drap_offset = -1;
 }
 
-static void clear_insn_state(struct insn_state *state)
+static void init_insn_state(struct insn_state *state, struct section *sec)
 {
        memset(state, 0, sizeof(*state));
        init_cfi_state(&state->cfi);
+
+       /*
+        * We need the full vmlinux for noinstr validation, otherwise we can
+        * not correctly determine insn->call_dest->sec (external symbols do
+        * not have a section).
+        */
+       if (vmlinux && sec)
+               state->noinstr = sec->noinstr;
 }
 
 /*
@@ -2354,24 +2362,34 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
        return 0;
 }
 
-static int validate_unwind_hints(struct objtool_file *file)
+static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
 {
        struct instruction *insn;
-       int ret, warnings = 0;
        struct insn_state state;
+       int ret, warnings = 0;
 
        if (!file->hints)
                return 0;
 
-       clear_insn_state(&state);
+       init_insn_state(&state, sec);
 
-       for_each_insn(file, insn) {
+       if (sec) {
+               insn = find_insn(file, sec, 0);
+               if (!insn)
+                       return 0;
+       } else {
+               insn = list_first_entry(&file->insn_list, typeof(*insn), list);
+       }
+
+       while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) {
                if (insn->hint && !insn->visited) {
                        ret = validate_branch(file, insn->func, insn, state);
                        if (ret && backtrace)
                                BT_FUNC("<=== (hint)", insn);
                        warnings += ret;
                }
+
+               insn = list_next_entry(insn, list);
        }
 
        return warnings;
@@ -2518,19 +2536,11 @@ static int validate_section(struct objtool_file *file, struct section *sec)
        struct symbol *func;
        int warnings = 0;
 
-       /*
-        * We need the full vmlinux for noinstr validation, otherwise we can
-        * not correctly determine insn->call_dest->sec (external symbols do
-        * not have a section).
-        */
-       if (vmlinux)
-               state.noinstr = sec->noinstr;
-
        list_for_each_entry(func, &sec->symbol_list, list) {
                if (func->type != STT_FUNC)
                        continue;
 
-               clear_insn_state(&state);
+               init_insn_state(&state, sec);
                state.cfi.cfa = initial_func_cfi.cfa;
                memcpy(&state.cfi.regs, &initial_func_cfi.regs,
                       CFI_NUM_REGS * sizeof(struct cfi_reg));
@@ -2545,12 +2555,16 @@ static int validate_section(struct objtool_file *file, struct section *sec)
 static int validate_vmlinux_functions(struct objtool_file *file)
 {
        struct section *sec;
+       int warnings = 0;
 
        sec = find_section_by_name(file->elf, ".noinstr.text");
        if (!sec)
                return 0;
 
-       return validate_section(file, sec);
+       warnings += validate_section(file, sec);
+       warnings += validate_unwind_hints(file, sec);
+
+       return warnings;
 }
 
 static int validate_functions(struct objtool_file *file)
@@ -2635,7 +2649,7 @@ int check(const char *_objname, bool orc)
                goto out;
        warnings += ret;
 
-       ret = validate_unwind_hints(&file);
+       ret = validate_unwind_hints(&file, NULL);
        if (ret < 0)
                goto out;
        warnings += ret;