This is a note to let you know that I've just added the patch titled Kconfig: add config option for asm goto w/ outputs to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kconfig-add-config-option-for-asm-goto-w-outputs.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 587f17018a2c6c414e41a312b002faaef60cf423 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Date: Fri, 14 Feb 2020 14:18:11 -0800 Subject: Kconfig: add config option for asm goto w/ outputs From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> commit 587f17018a2c6c414e41a312b002faaef60cf423 upstream. This allows C code to make use of compilers with support for output variables along the fallthrough path via preprocessor define: CONFIG_CC_HAS_ASM_GOTO_OUTPUT [ This is not used anywhere yet, and currently released compilers don't support this yet, but it's coming, and I have some local experimental patches to take advantage of it when it does - Linus ] Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- init/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) --- a/init/Kconfig +++ b/init/Kconfig @@ -38,6 +38,10 @@ config CC_HAS_ASM_GOTO_TIED_OUTPUT # Detect buggy gcc and clang, fixed in gcc-11 clang-14. def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .\n": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null) +config CC_HAS_ASM_GOTO_OUTPUT + depends on CC_HAS_ASM_GOTO + def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null) + config TOOLS_SUPPORT_RELR def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh) Patches currently in stable-queue which might be from ndesaulniers@xxxxxxxxxx are queue-5.4/kconfig-add-option-for-asm-goto-w-tied-outputs-to-workaround-clang-13-bug.patch queue-5.4/kconfig-add-config-option-for-asm-goto-w-outputs.patch