[STABLE BACKPORT 4.4.y, 4.9.y and 4.14.y] compiler.h: Raise minimum version of GCC to 5.1 for arm64
commit dca5244d2f5b94f1809f0c02a549edf41ccd5493 upstream.
GCC versions >= 4.9 and < 5.1 have been shown to emit memory references beyond the stack pointer, resulting in memory corruption if an interrupt is taken after the stack pointer has been adjusted but before the reference has been executed. This leads to subtle, infrequent data corruption such as the EXT4 problems reported by Russell King at the link below.
Life is too short for buggy compilers, so raise the minimum GCC version required by arm64 to 5.1.
Reported-by: Russell King linux@armlinux.org.uk Suggested-by: Arnd Bergmann arnd@kernel.org Signed-off-by: Will Deacon will@kernel.org Tested-by: Nathan Chancellor natechancellor@gmail.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Acked-by: Linus Torvalds torvalds@linux-foundation.org Cc: stable@vger.kernel.org # 4.4.y, 4.9.y and 4.14.y only Cc: Theodore Ts'o tytso@mit.edu Cc: Florian Weimer fweimer@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Nick Desaulniers ndesaulniers@google.com Link: https://lore.kernel.org/r/20210105154726.GD1551@shell.armlinux.org.uk Link: https://lore.kernel.org/r/20210112224832.10980-1-will@kernel.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com [will: backport to 4.4.y/4.9.y/4.14.y] Signed-off-by: Will Deacon will@kernel.org --- include/linux/compiler-gcc.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index af8b4a879934..3cc8adede67b 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -145,6 +145,12 @@
#if GCC_VERSION < 30200 # error Sorry, your compiler is too old - please upgrade it. +#elif defined(CONFIG_ARM64) && GCC_VERSION < 50100 +/* + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293 + * https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk + */ +# error Sorry, your version of GCC is too old - please use 5.1 or newer. #endif
#if GCC_VERSION < 30300
On Mon, Jan 18, 2021 at 5:54 AM Will Deacon will@kernel.org wrote:
commit dca5244d2f5b94f1809f0c02a549edf41ccd5493 upstream.
GCC versions >= 4.9 and < 5.1 have been shown to emit memory references beyond the stack pointer, resulting in memory corruption if an interrupt is taken after the stack pointer has been adjusted but before the reference has been executed. This leads to subtle, infrequent data corruption such as the EXT4 problems reported by Russell King at the link below.
Life is too short for buggy compilers, so raise the minimum GCC version required by arm64 to 5.1.
Reported-by: Russell King linux@armlinux.org.uk Suggested-by: Arnd Bergmann arnd@kernel.org Signed-off-by: Will Deacon will@kernel.org Tested-by: Nathan Chancellor natechancellor@gmail.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Acked-by: Linus Torvalds torvalds@linux-foundation.org Cc: stable@vger.kernel.org # 4.4.y, 4.9.y and 4.14.y only Cc: Theodore Ts'o tytso@mit.edu Cc: Florian Weimer fweimer@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Nick Desaulniers ndesaulniers@google.com Link: https://lore.kernel.org/r/20210105154726.GD1551@shell.armlinux.org.uk Link: https://lore.kernel.org/r/20210112224832.10980-1-will@kernel.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com [will: backport to 4.4.y/4.9.y/4.14.y]
Merging this from stable into "Android Common Kernel" trees that were built with AOSP GCC 4.9, I expect this to break some builds. Arnd, IIRC did you mention that AOSP GCC had picked up a fix? If so, did you verify that via disassembly, or gerrit patch file?
(AOSP GCC 4.9: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aa... master branch, roll back a few commits). It looks like AOSP GCC `#defines __android__ 1`.
I'm not arguing against a backport, just trying to think through how we'll need to sort this out downstream. (Revert or patch on top that checks for __android__, if AOSP GCC does in fact have a fix.)
Signed-off-by: Will Deacon will@kernel.org
include/linux/compiler-gcc.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index af8b4a879934..3cc8adede67b 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -145,6 +145,12 @@
#if GCC_VERSION < 30200 # error Sorry, your compiler is too old - please upgrade it. +#elif defined(CONFIG_ARM64) && GCC_VERSION < 50100 +/*
- */
+# error Sorry, your version of GCC is too old - please use 5.1 or newer. #endif
#if GCC_VERSION < 30300
2.30.0.284.gd98b1dd5eaa7-goog
On Tue, Jan 19, 2021 at 02:15:43PM -0800, Nick Desaulniers wrote:
On Mon, Jan 18, 2021 at 5:54 AM Will Deacon will@kernel.org wrote:
commit dca5244d2f5b94f1809f0c02a549edf41ccd5493 upstream.
GCC versions >= 4.9 and < 5.1 have been shown to emit memory references beyond the stack pointer, resulting in memory corruption if an interrupt is taken after the stack pointer has been adjusted but before the reference has been executed. This leads to subtle, infrequent data corruption such as the EXT4 problems reported by Russell King at the link below.
Life is too short for buggy compilers, so raise the minimum GCC version required by arm64 to 5.1.
Reported-by: Russell King linux@armlinux.org.uk Suggested-by: Arnd Bergmann arnd@kernel.org Signed-off-by: Will Deacon will@kernel.org Tested-by: Nathan Chancellor natechancellor@gmail.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Acked-by: Linus Torvalds torvalds@linux-foundation.org Cc: stable@vger.kernel.org # 4.4.y, 4.9.y and 4.14.y only Cc: Theodore Ts'o tytso@mit.edu Cc: Florian Weimer fweimer@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Nick Desaulniers ndesaulniers@google.com Link: https://lore.kernel.org/r/20210105154726.GD1551@shell.armlinux.org.uk Link: https://lore.kernel.org/r/20210112224832.10980-1-will@kernel.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com [will: backport to 4.4.y/4.9.y/4.14.y]
Merging this from stable into "Android Common Kernel" trees that were built with AOSP GCC 4.9, I expect this to break some builds. Arnd, IIRC did you mention that AOSP GCC had picked up a fix? If so, did you verify that via disassembly, or gerrit patch file?
(AOSP GCC 4.9: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aa... master branch, roll back a few commits). It looks like AOSP GCC `#defines __android__ 1`.
It seems like this is the source for that toolchain?
https://android.googlesource.com/toolchain/gcc
If so, it looks like that patch was picked up in this commit.
https://android.googlesource.com/toolchain/gcc/+/5ae0308a147ec3f6502fd321860...
Cheers, Nathan
On Wed, Jan 20, 2021 at 12:29 AM Nathan Chancellor natechancellor@gmail.com wrote:
On Tue, Jan 19, 2021 at 02:15:43PM -0800, Nick Desaulniers wrote:
Merging this from stable into "Android Common Kernel" trees that were built with AOSP GCC 4.9, I expect this to break some builds. Arnd, IIRC did you mention that AOSP GCC had picked up a fix? If so, did you verify that via disassembly, or gerrit patch file?
The only information I had was the fact that the gcc bug tracker mentioned it being picked up into the Android gcc and gcc-linaro. I verified that it was present in gcc-linaro, but did not also check the Android sources.
If so, it looks like that patch was picked up in this commit.
https://android.googlesource.com/toolchain/gcc/+/5ae0308a147ec3f6502fd321860...
Right.
Arnd
linux-stable-mirror@lists.linaro.org
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Arnd Bergmann -
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Nick Desaulniers -
Will Deacon