| Message ID | 20210209005719.803608-1-nathan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+ | expand |
On Mon, Feb 8, 2021 at 4:58 PM Nathan Chancellor <nathan@kernel.org> wrote: > > Similar to commit 28187dc8ebd9 ("ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN > depends on !LD_IS_LLD"), ld.lld prior to 13.0.0 does not properly > support aarch64 big endian, leading to the following build error when > CONFIG_CPU_BIG_ENDIAN is selected: > > ld.lld: error: unknown emulation: aarch64linuxb > > This has been resolved in LLVM 13. To avoid errors like this, only allow > CONFIG_CPU_BIG_ENDIAN to be selected if using ld.bfd or ld.lld 13.0.0 > and newer. > > While we are here, the indentation of this symbol used spaces since its > introduction in commit a872013d6d03 ("arm64: kconfig: allow > CPU_BIG_ENDIAN to be selected"). Change it to tabs to be consistent with > kernel coding style. > > Link: https://github.com/ClangBuiltLinux/linux/issues/380 > Link: https://github.com/ClangBuiltLinux/linux/issues/1288 > Link: https://github.com/llvm/llvm-project/commit/7605a9a009b5fa3bdac07e3131c8d82f6d08feb7 > Link: https://github.com/llvm/llvm-project/commit/eea34aae2e74e9b6fbdd5b95f479bc7f397bf387 > Reported-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> LGTM, thanks for implementing BE support for aarch64 in LLD, Fangrui! (And Nathan for the kernel patch+testing) Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > --- > > v1 -> v2: > > * Conditionally disable CONFIG_CPU_BIG_ENDIAN for older versions of > ld.lld now that proper support has been added to ld.lld 13+ (thanks to > the quick work of Fangrui Song). > > arch/arm64/Kconfig | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index f39568b28ec1..912da4e2ab59 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -952,8 +952,9 @@ choice > that is selected here. > > config CPU_BIG_ENDIAN > - bool "Build big-endian kernel" > - help > + bool "Build big-endian kernel" > + depends on !LD_IS_LLD || LLD_VERSION >= 130000 > + help > Say Y if you plan on running a kernel with a big-endian userspace. > > config CPU_LITTLE_ENDIAN > > base-commit: 92bf22614b21a2706f4993b278017e437f7785b3 > -- > 2.30.1 >
On Mon, 8 Feb 2021 17:57:20 -0700, Nathan Chancellor wrote: > Similar to commit 28187dc8ebd9 ("ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN > depends on !LD_IS_LLD"), ld.lld prior to 13.0.0 does not properly > support aarch64 big endian, leading to the following build error when > CONFIG_CPU_BIG_ENDIAN is selected: > > ld.lld: error: unknown emulation: aarch64linuxb > > [...] Applied to arm64 (for-next/misc), thanks! [1/1] arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+ https://git.kernel.org/arm64/c/e9c6deee00e9 Cheers,
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index f39568b28ec1..912da4e2ab59 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -952,8 +952,9 @@ choice that is selected here. config CPU_BIG_ENDIAN - bool "Build big-endian kernel" - help + bool "Build big-endian kernel" + depends on !LD_IS_LLD || LLD_VERSION >= 130000 + help Say Y if you plan on running a kernel with a big-endian userspace. config CPU_LITTLE_ENDIAN
Similar to commit 28187dc8ebd9 ("ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN depends on !LD_IS_LLD"), ld.lld prior to 13.0.0 does not properly support aarch64 big endian, leading to the following build error when CONFIG_CPU_BIG_ENDIAN is selected: ld.lld: error: unknown emulation: aarch64linuxb This has been resolved in LLVM 13. To avoid errors like this, only allow CONFIG_CPU_BIG_ENDIAN to be selected if using ld.bfd or ld.lld 13.0.0 and newer. While we are here, the indentation of this symbol used spaces since its introduction in commit a872013d6d03 ("arm64: kconfig: allow CPU_BIG_ENDIAN to be selected"). Change it to tabs to be consistent with kernel coding style. Link: https://github.com/ClangBuiltLinux/linux/issues/380 Link: https://github.com/ClangBuiltLinux/linux/issues/1288 Link: https://github.com/llvm/llvm-project/commit/7605a9a009b5fa3bdac07e3131c8d82f6d08feb7 Link: https://github.com/llvm/llvm-project/commit/eea34aae2e74e9b6fbdd5b95f479bc7f397bf387 Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- v1 -> v2: * Conditionally disable CONFIG_CPU_BIG_ENDIAN for older versions of ld.lld now that proper support has been added to ld.lld 13+ (thanks to the quick work of Fangrui Song). arch/arm64/Kconfig | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) base-commit: 92bf22614b21a2706f4993b278017e437f7785b3