compiler/gcc: Raise minimum GCC version for kernel builds to 4.8

It is very rare to see versions of GCC prior to 4.8 being used to build the mainline kernel. These old compilers are also know to have codegen issues which can lead to silent miscompilation: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 Raise the minimum GCC version for kernel build to 4.8 and remove some tautological Kconfig dependencies as a consequence. Cc: Masahiro Yamada <[email protected]> Acked-by: Arnd Bergmann <[email protected]> Reviewed-by: Nick Desaulniers <[email protected]> Signed-off-by: Will Deacon <[email protected]>
torvalds · Apr 15, 2020 · 5429ef6 · 5429ef6
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commit 5429ef6
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Showing 6 changed files with 10 additions and 13 deletions.
diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
@@ -29,7 +29,7 @@ you probably needn't concern yourself with pcmciautils.
 ====================== =============== ========================================
  Program Minimal version Command to check the version
 ====================== =============== ========================================
-GNU C 4.6 gcc --version
+GNU C 4.8 gcc --version
 GNU make 3.81 make --version
 binutils 2.23 ld -v
 flex 2.5.35 flex --version

diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
@@ -30,7 +30,7 @@ config CRYPTO_SHA1_ARM_NEON
 
 config CRYPTO_SHA1_ARM_CE
  tristate "SHA1 digest algorithm (ARM v8 Crypto Extensions)"
- depends on KERNEL_MODE_NEON && (CC_IS_CLANG || GCC_VERSION >= 40800)
+ depends on KERNEL_MODE_NEON
  select CRYPTO_SHA1_ARM
  select CRYPTO_HASH
  help
@@ -39,7 +39,7 @@ config CRYPTO_SHA1_ARM_CE
 
 config CRYPTO_SHA2_ARM_CE
  tristate "SHA-224/256 digest algorithm (ARM v8 Crypto Extensions)"
- depends on KERNEL_MODE_NEON && (CC_IS_CLANG || GCC_VERSION >= 40800)
+ depends on KERNEL_MODE_NEON
  select CRYPTO_SHA256_ARM
  select CRYPTO_HASH
  help
@@ -96,7 +96,7 @@ config CRYPTO_AES_ARM_BS
 
 config CRYPTO_AES_ARM_CE
  tristate "Accelerated AES using ARMv8 Crypto Extensions"
- depends on KERNEL_MODE_NEON && (CC_IS_CLANG || GCC_VERSION >= 40800)
+ depends on KERNEL_MODE_NEON
  select CRYPTO_SKCIPHER
  select CRYPTO_LIB_AES
  select CRYPTO_SIMD
@@ -106,7 +106,7 @@ config CRYPTO_AES_ARM_CE
 
 config CRYPTO_GHASH_ARM_CE
  tristate "PMULL-accelerated GHASH using NEON/ARMv8 Crypto Extensions"
- depends on KERNEL_MODE_NEON && (CC_IS_CLANG || GCC_VERSION >= 40800)
+ depends on KERNEL_MODE_NEON
  select CRYPTO_HASH
  select CRYPTO_CRYPTD
  select CRYPTO_GF128MUL
@@ -118,13 +118,13 @@ config CRYPTO_GHASH_ARM_CE
 
 config CRYPTO_CRCT10DIF_ARM_CE
  tristate "CRCT10DIF digest algorithm using PMULL instructions"
- depends on KERNEL_MODE_NEON && (CC_IS_CLANG || GCC_VERSION >= 40800)
+ depends on KERNEL_MODE_NEON
  depends on CRC_T10DIF
  select CRYPTO_HASH
 
 config CRYPTO_CRC32_ARM_CE
  tristate "CRC32(C) digest algorithm using CRC and/or PMULL instructions"
- depends on KERNEL_MODE_NEON && (CC_IS_CLANG || GCC_VERSION >= 40800)
+ depends on KERNEL_MODE_NEON
  depends on CRC32
  select CRYPTO_HASH
 

diff --git a/crypto/Kconfig b/crypto/Kconfig
@@ -316,7 +316,6 @@ config CRYPTO_AEGIS128
 config CRYPTO_AEGIS128_SIMD
  bool "Support SIMD acceleration for AEGIS-128"
  depends on CRYPTO_AEGIS128 && ((ARM || ARM64) && KERNEL_MODE_NEON)
- depends on !ARM || CC_IS_CLANG || GCC_VERSION >= 40800
  default y
 
 config CRYPTO_AEGIS128_AESNI_SSE2

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
@@ -10,7 +10,8 @@
  + __GNUC_MINOR__ * 100 \
  + __GNUC_PATCHLEVEL__)
 
-#if GCC_VERSION < 40600
+/* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 */
+#if GCC_VERSION < 40800
 # error Sorry, your compiler is too old - please upgrade it.
 #endif
 
@@ -126,9 +127,7 @@
 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
 #define __HAVE_BUILTIN_BSWAP32__
 #define __HAVE_BUILTIN_BSWAP64__
-#if GCC_VERSION >= 40800
 #define __HAVE_BUILTIN_BSWAP16__
-#endif
 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
 
 #if GCC_VERSION >= 70000

diff --git a/init/Kconfig b/init/Kconfig
@@ -1285,7 +1285,6 @@ config LD_DEAD_CODE_DATA_ELIMINATION
  bool "Dead code and data elimination (EXPERIMENTAL)"
  depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
  depends on EXPERT
- depends on !(FUNCTION_TRACER && CC_IS_GCC && GCC_VERSION < 40800)
  depends on $(cc-option,-ffunction-sections -fdata-sections)
  depends on $(ld-option,--gc-sections)
  help

diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
@@ -8,7 +8,7 @@ config HAVE_GCC_PLUGINS
 menuconfig GCC_PLUGINS
  bool "GCC plugins"
  depends on HAVE_GCC_PLUGINS
- depends on CC_IS_GCC && GCC_VERSION >= 40800
+ depends on CC_IS_GCC
  depends on $(success,$(srctree)/scripts/gcc-plugin.sh $(CC))
  default y
  help