linux-kernel - [PATCH] compiler-gcc: remove comment about gcc 4.5 from unreachable()

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Message-Id: <20181015212428.260810-1-ndesaulniers@google.com>
Date:   Mon, 15 Oct 2018 14:24:27 -0700
From:   ndesaulniers@...gle.com
To:     miguel.ojeda.sandonis@...il.com
Cc:     luto@...capital.net, jpoimboe@...hat.com, natechancellor@...il.com,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Kees Cook <keescook@...omium.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Ingo Molnar <mingo@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Arnd Bergmann <arnd@...db.de>,
        Will Deacon <will.deacon@....com>,
        Joe Perches <joe@...ches.com>, linux-kernel@...r.kernel.org
Subject: [PATCH] compiler-gcc: remove comment about gcc 4.5 from unreachable()

Remove the comment about being unable to detect __builtin_unreachable.
__builtin_unreachable was implemented in the GCC 4.5 timeframe. The
kernel's minimum supported version of GCC is 4.6 since commit
cafa0010cd51 ("Raise the minimum required gcc version to 4.6"). Commit
cb984d101b30 ("compiler-gcc: integrate the various compiler-gcc[345].h
files") shows that unreachable() had different guards based on GCC
version.

Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@...il.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@...gle.com>
---
 include/linux/compiler-gcc.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 4d36b27214fd..9890411b33d5 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -107,10 +107,6 @@
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer
  * control elsewhere.
- *
- * Early snapshots of gcc 4.5 don't support this and we can't detect
- * this in the preprocessor, but we can live with this because they're
- * unreleased.  Really, we need to have autoconf for the kernel.
  */
 #define unreachable() \
 	do {					\
-- 
2.19.1.331.ge82ca0e54c-goog