From: Kees Cook <keescook@chromium.org>
Date: Sun, 6 Feb 2022 17:12:50 +0000 (-0800)
Subject: gcc-plugins/stackleak: Ignore .noinstr.text and .entry.text
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ae978009fc013e3166c9f523f8b17e41a3c0286e;p=linux.git

gcc-plugins/stackleak: Ignore .noinstr.text and .entry.text

The .noinstr.text section functions may not have "current()" sanely
available. Similarly true for .entry.text, though such a check is
currently redundant. Add a check for both. In an x86_64 defconfig build,
the following functions no longer receive stackleak instrumentation:

	__do_fast_syscall_32()
	do_int80_syscall_32()
	do_machine_check()
	do_syscall_64()
	exc_general_protection()
	fixup_bad_iret()

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---

diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c
index b04aa8e91a41f..42f0252ee2a4e 100644
--- a/scripts/gcc-plugins/stackleak_plugin.c
+++ b/scripts/gcc-plugins/stackleak_plugin.c
@@ -463,6 +463,10 @@ static bool stackleak_gate(void)
 			return false;
 		if (STRING_EQUAL(section, ".meminit.text"))
 			return false;
+		if (STRING_EQUAL(section, ".noinstr.text"))
+			return false;
+		if (STRING_EQUAL(section, ".entry.text"))
+			return false;
 	}
 
 	return track_frame_size >= 0;