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    Subject[PATCH] [7/98] i8k: Tell gcc that *regs gets clobbered
    Date
    2.6.35-longterm review patch.  If anyone has any objections, please let me know.

    ------------------
    From: Jim Bos <jim876@xs4all.nl>

    [ upstream commit 6b4e81db2552bad04100e7d5ddeed7e848f53b48 ]

    More recent GCC caused the i8k driver to stop working, on Slackware
    compiler was upgraded from gcc-4.4.4 to gcc-4.5.1 after which it didn't
    work anymore, meaning the driver didn't load or gave total nonsensical
    output.

    As it turned out the asm(..) statement forgot to mention it modifies the
    *regs variable.

    Credits to Andi Kleen and Andreas Schwab for providing the fix.

    Signed-off-by: Jim Bos <jim876@xs4all.nl>
    Cc: Andi Kleen <andi@firstfloor.org>
    Cc: Andreas Schwab <schwab@linux-m68k.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Andi Kleen <ak@linux.intel.com>

    Index: linux-2.6.35.y/drivers/char/i8k.c
    ===================================================================
    --- linux-2.6.35.y.orig/drivers/char/i8k.c
    +++ linux-2.6.35.y/drivers/char/i8k.c
    @@ -141,7 +141,7 @@ static int i8k_smm(struct smm_regs *regs
    "lahf\n\t"
    "shrl $8,%%eax\n\t"
    "andl $1,%%eax\n"
    - :"=a"(rc)
    + :"=a"(rc), "+m" (*regs)
    : "a"(regs)
    : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
    #else
    @@ -166,7 +166,8 @@ static int i8k_smm(struct smm_regs *regs
    "movl %%edx,0(%%eax)\n\t"
    "lahf\n\t"
    "shrl $8,%%eax\n\t"
    - "andl $1,%%eax\n":"=a"(rc)
    + "andl $1,%%eax\n"
    + :"=a"(rc), "+m" (*regs)
    : "a"(regs)
    : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
    #endif

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