[PATCH v5 18/22] kallsyms: Drop CONFIG_CFI_CLANG workarounds

From: Sami Tolvanen <samitolvanen@google.com>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	 Peter Zijlstra <peterz@infradead.org>,
	x86@kernel.org,  Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	 Mark Rutland <mark.rutland@arm.com>,
	Nathan Chancellor <nathan@kernel.org>,
	 Nick Desaulniers <ndesaulniers@google.com>,
	Joao Moreira <joao@overdrivepizza.com>,
	 Sedat Dilek <sedat.dilek@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	 linux-hardening@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,  llvm@lists.linux.dev,
	Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH v5 18/22] kallsyms: Drop CONFIG_CFI_CLANG workarounds
Date: Thu,  8 Sep 2022 14:55:00 -0700	[thread overview]
Message-ID: <20220908215504.3686827-19-samitolvanen@google.com> (raw)
In-Reply-To: <20220908215504.3686827-1-samitolvanen@google.com>

With -fsanitize=kcfi, the compiler no longer renames static
functions with CONFIG_CFI_CLANG + ThinLTO. Drop the code that cleans
up the ThinLTO hash from the function names.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
---
 kernel/kallsyms.c | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 3e7e2c2ad2f7..b27e6ea31f8b 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -159,7 +159,6 @@ static bool cleanup_symbol_name(char *s)
 	 * character in an identifier in C. Suffixes observed:
 	 * - foo.llvm.[0-9a-f]+
 	 * - foo.[0-9a-f]+
-	 * - foo.[0-9a-f]+.cfi_jt
 	 */
 	res = strchr(s, '.');
 	if (res) {
@@ -167,22 +166,6 @@ static bool cleanup_symbol_name(char *s)
 		return true;
 	}
 
-	if (!IS_ENABLED(CONFIG_CFI_CLANG) ||
-	    !IS_ENABLED(CONFIG_LTO_CLANG_THIN) ||
-	    CONFIG_CLANG_VERSION >= 130000)
-		return false;
-
-	/*
-	 * Prior to LLVM 13, the following suffixes were observed when thinLTO
-	 * and CFI are both enabled:
-	 * - foo$[0-9]+
-	 */
-	res = strrchr(s, '$');
-	if (res) {
-		*res = '\0';
-		return true;
-	}
-
 	return false;
 }
 
-- 
2.37.2.789.g6183377224-goog

