Messages in this thread Patch in this message | | | From | Uros Bizjak <> | Subject | [RFC PATCH 2/4] x86/percpu: Detect compiler support for named address spaces | Date | Sun, 1 Oct 2023 15:14:34 +0200 |
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Detect compiler support for named address spaces by trying to compile a small testcase that includes __seg_gs and __seg_gs keywords. Reflect successful compilation in CC_HAS_NAMED_AS and set USE_X86_SEG_SUPPORT to signal when segment qualifiers should be used.
Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> --- arch/x86/Kconfig | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 66bfabae8814..f66fa5bf1f78 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2388,6 +2388,13 @@ source "kernel/livepatch/Kconfig" endmenu +config CC_HAS_NAMED_AS + def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -c -o /dev/null) + +config USE_X86_SEG_SUPPORT + def_bool y + depends on CC_HAS_NAMED_AS && SMP + config CC_HAS_SLS def_bool $(cc-option,-mharden-sls=all) -- 2.41.0
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