[PATCH] sanitizer: do not inline no-sanitize into sanitizer fn

[Martin Liška]

Hello.

The patch is follow up of the kernel discussion:
https://lore.kernel.org/lkml/CANpmjNNRz5OVKb6PE7K6GjfoGbht_ZhyPkNG9aD+KjNDzK7hGg@mail.gmail.com/

The patch changes inliner in the following way:
1) do not compare caller and callee sanitizer attributes
    for always_inline functions - that matches Clang behavior
2) do not inline if one function is sanitized and the second
    one isn't (for all ASAN, UBSAN, TSAN, LSAN sanitizers);
    that also matches what Clang does

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin

gcc/ChangeLog:

	* cif-code.def (ATTRIBUTE_MISMATCH): Rename to...
	(SANITIZE_ATTRIBUTE_MISMATCH): ...this.
	* ipa-inline.c (sanitize_attrs_match_for_inline_p):
	Handle all sanitizer options.
	(can_inline_edge_p): Use renamed CIF_* enum value.

gcc/testsuite/ChangeLog:

	* c-c++-common/asan/inline.c: New test.
	* c-c++-common/tsan/inline.c: New test.
	* c-c++-common/ubsan/inline.c: New test.
---
  gcc/cif-code.def                          |  7 +++---
  gcc/ipa-inline.c                          | 29 ++++++++++++++---------
  gcc/testsuite/c-c++-common/asan/inline.c  | 20 ++++++++++++++++
  gcc/testsuite/c-c++-common/tsan/inline.c  | 20 ++++++++++++++++
  gcc/testsuite/c-c++-common/ubsan/inline.c | 20 ++++++++++++++++
  5 files changed, 82 insertions(+), 14 deletions(-)
  create mode 100644 gcc/testsuite/c-c++-common/asan/inline.c
  create mode 100644 gcc/testsuite/c-c++-common/tsan/inline.c
  create mode 100644 gcc/testsuite/c-c++-common/ubsan/inline.c

diff --git a/gcc/cif-code.def b/gcc/cif-code.def
index 31c18c6c691..c65b2477203 100644
--- a/gcc/cif-code.def
+++ b/gcc/cif-code.def
@@ -128,9 +128,10 @@ DEFCIFCODE(OPTIMIZATION_MISMATCH, CIF_FINAL_ERROR,
  DEFCIFCODE(USES_COMDAT_LOCAL, CIF_FINAL_ERROR,
  	   N_("callee refers to comdat-local symbols"))
  
-/* We can't inline because of mismatched caller/callee attributes.  */
-DEFCIFCODE(ATTRIBUTE_MISMATCH, CIF_FINAL_ERROR,
-	   N_("function attribute mismatch"))
+/* We can't inline because of mismatched caller/callee
+   sanitizer attributes.  */
+DEFCIFCODE(SANITIZE_ATTRIBUTE_MISMATCH, CIF_FINAL_ERROR,
+	   N_("sanitizer function attribute mismatch"))
  
  /* We can't inline because the user requests only static functions
     but the function has external linkage for live patching purpose.  */
diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
index f71443feff7..edf4095bcbc 100644
--- a/gcc/ipa-inline.c
+++ b/gcc/ipa-inline.c
@@ -264,18 +264,25 @@ sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
    if (!caller || !callee)
      return true;
  
-  /* Allow inlining always_inline functions into no_sanitize_address
-     functions.  */
-  if (!sanitize_flags_p (SANITIZE_ADDRESS, caller)
-      && lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
+  /* Follow clang and allow inlining for always_inline functions.  */
+  if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
      return true;
  
-  return ((sanitize_flags_p (SANITIZE_ADDRESS, caller)
-	   == sanitize_flags_p (SANITIZE_ADDRESS, callee))
-	  && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller)
-	      == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee))
-	  && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller)
-	      == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee)));
+  const sanitize_code codes[] =
+    {
+      SANITIZE_ADDRESS,
+      SANITIZE_THREAD,
+      SANITIZE_LEAK,
+      SANITIZE_UNDEFINED,
+      SANITIZE_UNDEFINED_NONDEFAULT
+    };
+
+  for (unsigned i = 0; i < sizeof (codes) / sizeof (codes[0]); i++)
+    if (sanitize_flags_p (codes[i], caller)
+	!= sanitize_flags_p (codes[i], callee))
+      return false;
+
+  return true;
  }
  
  /* Used for flags where it is safe to inline when caller's value is
@@ -382,7 +389,7 @@ can_inline_edge_p (struct cgraph_edge *e, bool report,
    /* Don't inline a function with mismatched sanitization attributes. */
    else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
      {
-      e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
+      e->inline_failed = CIF_SANITIZE_ATTRIBUTE_MISMATCH;
        inlinable = false;
      }
    if (!inlinable && report)
diff --git a/gcc/testsuite/c-c++-common/asan/inline.c b/gcc/testsuite/c-c++-common/asan/inline.c
new file mode 100644
index 00000000000..7c36702cf9e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/inline.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=address -c -O3 -fdump-tree-optimized" } */
+
+int x;
+
+static inline
+__attribute__((no_sanitize("address")))
+void do_not_sanitize(void)
+{
+  x++;
+}
+
+void
+sanitize_this(void)
+{
+  x++;
+  do_not_sanitize();
+}
+
+/* { dg-final { scan-tree-dump-times "Function do_not_sanitize" 1 "optimized" } } */
diff --git a/gcc/testsuite/c-c++-common/tsan/inline.c b/gcc/testsuite/c-c++-common/tsan/inline.c
new file mode 100644
index 00000000000..7fb3e576f54
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/tsan/inline.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=thread -c -O3 -fdump-tree-optimized" } */
+
+int x;
+
+static inline
+__attribute__((no_sanitize("thread")))
+void do_not_sanitize(void)
+{
+  x++;
+}
+
+void
+sanitize_this(void)
+{
+  x++;
+  do_not_sanitize();
+}
+
+/* { dg-final { scan-tree-dump-times "Function do_not_sanitize" 1 "optimized" } } */
diff --git a/gcc/testsuite/c-c++-common/ubsan/inline.c b/gcc/testsuite/c-c++-common/ubsan/inline.c
new file mode 100644
index 00000000000..de9660427f6
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/inline.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=vla-bound -c -O3 -fdump-tree-optimized" } */
+
+int x;
+
+static inline
+__attribute__((no_sanitize("undefined")))
+void do_not_sanitize(void)
+{
+  x++;
+}
+
+void
+sanitize_this(void)
+{
+  x++;
+  do_not_sanitize();
+}
+
+/* { dg-final { scan-tree-dump-times "Function do_not_sanitize" 1 "optimized" } } */
-- 
2.26.2