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    Subject[PATCH 5.17 175/298] x86: drop bogus "cc" clobber from __try_cmpxchg_user_asm()
    Date
    From: Jan Beulich <jbeulich@suse.com>

    [ Upstream commit 1df931d95f4dc1c11db1123e85d4e08156e46ef9 ]

    As noted (and fixed) a couple of times in the past, "=@cc<cond>" outputs
    and clobbering of "cc" don't work well together. The compiler appears to
    mean to reject such, but doesn't - in its upstream form - quite manage
    to yet for "cc". Furthermore two similar macros don't clobber "cc", and
    clobbering "cc" is pointless in asm()-s for x86 anyway - the compiler
    always assumes status flags to be clobbered there.

    Fixes: 989b5db215a2 ("x86/uaccess: Implement macros for CMPXCHG on user addresses")
    Signed-off-by: Jan Beulich <jbeulich@suse.com>
    Message-Id: <485c0c0b-a3a7-0b7c-5264-7d00c01de032@suse.com>
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/x86/include/asm/uaccess.h | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
    index 1c14bcce88f2..729ecf1e546c 100644
    --- a/arch/x86/include/asm/uaccess.h
    +++ b/arch/x86/include/asm/uaccess.h
    @@ -466,7 +466,7 @@ do { \
    [ptr] "+m" (*_ptr), \
    [old] "+a" (__old) \
    : [new] ltype (__new) \
    - : "memory", "cc"); \
    + : "memory"); \
    if (unlikely(__err)) \
    goto label; \
    if (unlikely(!success)) \
    --
    2.35.1


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