Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

13fbe991 · Linus Torvalds <[email protected]> · 2019-07-27 20:49:43 -07:00

Pull objtool fix from Thomas Gleixner:
 "A single robustness fix for objtool to handle unbalanced CLAC
  invocations under all circumstances"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Improve UACCESS coverage

Commit: 13fbe991b5b1bbb52ede39be11d5c196721349bf
Parents: 88c50834 · 882a0db9

Merge commit. Changes below are compared with the first parent: 88c50834.

Changes

2 files changed · +6 −4

File	Status	Add	Del	Content
tools/objtool/check.c	modified	+4	−3	View file
tools/objtool/check.h	modified	+2	−1	View file

tools/objtool/check.c

View file

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 5f26620..176f2f0 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1946,6 +1946,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 	struct alternative *alt;
 	struct instruction *insn, *next_insn;
 	struct section *sec;
+	u8 visited;
 	int ret;
 
 	insn = first;
@@ -1972,12 +1973,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 			return 1;
 		}
 
+		visited = 1 << state.uaccess;
 		if (insn->visited) {
 			if (!insn->hint && !insn_state_match(insn, &state))
 				return 1;
 
-			/* If we were here with AC=0, but now have AC=1, go again */
-			if (insn->state.uaccess || !state.uaccess)
+			if (insn->visited & visited)
 				return 0;
 		}
 
@@ -2024,7 +2025,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 		} else
 			insn->state = state;
 
-		insn->visited = true;
+		insn->visited |= visited;
 
 		if (!insn->ignore_alts) {
 			bool skip_orig = false;

tools/objtool/check.h

View file

diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index b881faf..6d875ca 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -33,8 +33,9 @@ struct instruction {
 	unsigned int len;
 	enum insn_type type;
 	unsigned long immediate;
-	bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
+	bool alt_group, dead_end, ignore, hint, save, restore, ignore_alts;
 	bool retpoline_safe;
+	u8 visited;
 	struct symbol *call_dest;
 	struct instruction *jump_dest;
 	struct instruction *first_jump_src;