Hi On Donnerstag, 7. Februar 2008, Greg KH wrote: > 2.6.24-stable review patch. If anyone has any objections, please let us know. > > ------------------ > From: Thomas Gleixner <[EMAIL PROTECTED]> > > The exception fixup for the futex macros __futex_atomic_op1/2 and > futex_atomic_cmpxchg_inatomic() is missing an entry when the lock > prefix is replaced by a NOP via SMP alternatives. > > Chuck Ebert tracked this down from the information provided in: > https://bugzilla.redhat.com/show_bug.cgi?id=429412 > > A possible solution would be to add another fixup after the > LOCK_PREFIX, so both the LOCK and NOP case have their own entry in the > exception table, but it's not really worth the trouble. > > Simply replace LOCK_PREFIX with lock and keep those untouched by SMP > alternatives. > > Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]> > Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]> > > --- > include/asm-x86/futex_32.h | 6 +++--- > include/asm-x86/futex_64.h | 6 +++--- > 2 files changed, 6 insertions(+), 6 deletions(-)
This patch seems to break compilation on x86_64 (i386 builds fine).
[...]
CC kernel/time/tick-sched.o
LD kernel/time/built-in.o
CC kernel/futex.o
In file included from include/asm/futex.h:4,
from kernel/futex.c:59:
include/asm/futex_64.h: In function ‘futex_atomic_op_inuser’:
include/asm/futex_64.h:69: error: expected ‘:’ or ‘)’ before ‘lock’
include/asm/futex_64.h:69: error: stray ‘\’ in program
In file included from include/asm/futex.h:4,
from kernel/futex.c:59:
include/asm/futex_64.h:69:61: error: invalid suffix "b" on integer constant
include/asm/futex_64.h:69: error: stray ‘\’ in program
include/asm/futex_64.h:69: error: stray ‘\’ in program
include/asm/futex_64.h:72: error: expected ‘:’ or ‘)’ before ‘lock’
include/asm/futex_64.h:72: error: stray ‘\’ in program
include/asm/futex_64.h:72:63: error: invalid suffix "b" on integer constant
include/asm/futex_64.h:72: error: stray ‘\’ in program
include/asm/futex_64.h:72: error: stray ‘\’ in program
include/asm/futex_64.h:75: error: expected ‘:’ or ‘)’ before ‘lock’
include/asm/futex_64.h:75: error: stray ‘\’ in program
include/asm/futex_64.h:75:62: error: invalid suffix "b" on integer constant
include/asm/futex_64.h:75: error: stray ‘\’ in program
include/asm/futex_64.h:75: error: stray ‘\’ in program
include/asm/futex_64.h:51: warning: unused variable ‘tem’
make[1]: *** [kernel/futex.o] Fehler 1
make: *** [kernel] Fehler 2
Tested on current debian-amd64/ unstable.
ii binutils 2.18.1~cvs20080103-1
The GNU assembler, linker and binary utiliti
ii gcc-4.2 4.2.3-1
The GNU C compiler
ii gcc-4.2-base 4.2.3-1
The GNU Compiler Collection (base package)
[...]
> --- a/include/asm-x86/futex_64.h
> +++ b/include/asm-x86/futex_64.h
> @@ -27,7 +27,7 @@
> "1: movl %2, %0\n\
> movl %0, %3\n" \
> insn "\n" \
> -"2: " LOCK_PREFIX "cmpxchgl %3, %2\n\
> +"2: "lock cmpxchgl %3, %2\n\
> jnz 1b\n\
> 3: .section .fixup,\"ax\"\n\
> 4: mov %5, %1\n\
> @@ -62,7 +62,7 @@ futex_atomic_op_inuser (int encoded_op,
> __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
> break;
> case FUTEX_OP_ADD:
> - __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
> + __futex_atomic_op1("lock xaddl %0, %2", ret, oldval,
> uaddr, oparg);
> break;
> case FUTEX_OP_OR:
> @@ -101,7 +101,7 @@ futex_atomic_cmpxchg_inatomic(int __user
> return -EFAULT;
>
> __asm__ __volatile__(
> - "1: " LOCK_PREFIX "cmpxchgl %3, %1 \n"
> + "1: lock cmpxchgl %3, %1 \n"
>
> "2: .section .fixup, \"ax\" \n"
> "3: mov %2, %0 \n"
Regards
Stefan Lippers-Hollmann
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