From: Nick Desaulniers <ndesaulniers@google.com> Date: 2021-08-30 21:38:55
tglx notes:
This function [futex_detect_cmpxchg] is only needed when an
architecture has to runtime discover whether the CPU supports it or
not. ARM has unconditional support for this, so the obvious thing to
do is the below.
Fixes linkage failure from Clang randconfigs:
kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24 against `.init.text'
and boot failures for CONFIG_THUMB2_KERNEL.
Link: https://github.com/ClangBuiltLinux/linux/issues/325
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Thomas Gleixner <redacted>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
arch/arm/Kconfig | 1 +
1 file changed, 1 insertion(+)
From: Thomas Gleixner <hidden> Date: 2021-08-30 23:17:50
On Mon, Aug 30 2021 at 14:38, Nick Desaulniers wrote:
tglx notes:
This function [futex_detect_cmpxchg] is only needed when an
architecture has to runtime discover whether the CPU supports it or
not. ARM has unconditional support for this, so the obvious thing to
do is the below.
Fixes linkage failure from Clang randconfigs:
kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24 against `.init.text'
and boot failures for CONFIG_THUMB2_KERNEL.
Link: https://github.com/ClangBuiltLinux/linux/issues/325
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Thomas Gleixner <redacted>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
On Mon, Aug 30, 2021 at 02:38:43PM -0700, Nick Desaulniers wrote:
tglx notes:
This function [futex_detect_cmpxchg] is only needed when an
architecture has to runtime discover whether the CPU supports it or
not. ARM has unconditional support for this, so the obvious thing to
do is the below.
Fixes linkage failure from Clang randconfigs:
kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24 against `.init.text'
and boot failures for CONFIG_THUMB2_KERNEL.
Link: https://github.com/ClangBuiltLinux/linux/issues/325
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Thomas Gleixner <redacted>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
On Mon, Aug 30, 2021 at 11:38 PM Nick Desaulniers
[off-list ref] wrote:
tglx notes:
This function [futex_detect_cmpxchg] is only needed when an
architecture has to runtime discover whether the CPU supports it or
not. ARM has unconditional support for this, so the obvious thing to
do is the below.
Fixes linkage failure from Clang randconfigs:
kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24 against `.init.text'
and boot failures for CONFIG_THUMB2_KERNEL.
Link: https://github.com/ClangBuiltLinux/linux/issues/325
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Thomas Gleixner <redacted>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
LGTM
Reviewed-by: Linus Walleij <redacted>
Please put this into Russell's patch tracker!
Yours,
Linus Walleij
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
From: Nick Desaulniers <ndesaulniers@google.com> Date: 2021-09-16 23:27:02
On Thu, Sep 16, 2021 at 3:40 PM Linus Walleij [off-list ref] wrote:
On Mon, Aug 30, 2021 at 11:38 PM Nick Desaulniers
[off-list ref] wrote:
quoted
tglx notes:
This function [futex_detect_cmpxchg] is only needed when an
architecture has to runtime discover whether the CPU supports it or
not. ARM has unconditional support for this, so the obvious thing to
do is the below.
Fixes linkage failure from Clang randconfigs:
kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24 against `.init.text'
and boot failures for CONFIG_THUMB2_KERNEL.
Link: https://github.com/ClangBuiltLinux/linux/issues/325
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Thomas Gleixner <redacted>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
LGTM
Reviewed-by: Linus Walleij <redacted>
Please put this into Russell's patch tracker!
On Mon, Aug 30, 2021 at 11:38 PM 'Nick Desaulniers' via Clang Built
Linux [off-list ref] wrote:
tglx notes:
This function [futex_detect_cmpxchg] is only needed when an
architecture has to runtime discover whether the CPU supports it or
not. ARM has unconditional support for this, so the obvious thing to
do is the below.
Fixes linkage failure from Clang randconfigs:
kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24 against `.init.text'
and boot failures for CONFIG_THUMB2_KERNEL.
Link: https://github.com/ClangBuiltLinux/linux/issues/325
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Thomas Gleixner <redacted>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Nice! I did remember that we had come up with a number of solutions
for the build error and that at least one of them was an obvious and
nice fix, but I could never figure out what it was. This is clearly better
than any of the other ones I had found when I last looked.
I would add a reference to the commit that introduced the conditional,
and a request for backports as well:
See-also: 03b8c7b623c8 ("futex: Allow architectures to skip
futex_atomic_cmpxchg_inatomic() test")
Cc: stable@vger.kernel.org # v3.14+
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Fri, Sep 17, 2021 at 9:11 AM Arnd Bergmann [off-list ref] wrote:
Nice! I did remember that we had come up with a number of solutions
for the build error and that at least one of them was an obvious and
nice fix, but I could never figure out what it was. This is clearly better
than any of the other ones I had found when I last looked.