Commit 6b4e81db authored Nov 13, 2010 by Jim Bos Committed by Linus Torvalds Nov 13, 2010

i8k: Tell gcc that *regs gets clobbered



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>

parent ed3aada1

drivers/char/i8k.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -142,7 +142,7 @@ 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
		@@ -167,7 +167,8 @@ 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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