Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Lots of asm-*/futex.h call pagefault_enable and pagefault_disable, which are declared in linux/uaccess.h, without including linux/uaccess.h. They all include asm/uaccess.h, so this patch replaces asm/uaccess.h with linux/uaccess.h. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The LL / SC loops in __futex_atomic_op() have the usual fixups necessary
for memory acccesses to userspace from kernel space installed:
__asm__ __volatile__(
" .set push \n"
" .set noat \n"
" .set mips3 \n"
"1: ll %1, %4 # __futex_atomic_op \n"
" .set mips0 \n"
" " insn " \n"
" .set mips3 \n"
"2: sc $1, %2 \n"
" beqz $1, 1b \n"
__WEAK_LLSC_MB
"3: \n"
" .set pop \n"
" .set mips0 \n"
" .section .fixup,\"ax\" \n"
"4: li %0, %6 \n"
" j 2b \n" <-----
" .previous \n"
" .section __ex_table,\"a\" \n"
" "__UA_ADDR "\t1b, 4b \n"
" "__UA_ADDR "\t2b, 4b \n"
" .previous \n"
: "=r" (ret), "=&r" (oldval), "=R" (*uaddr)
: "0" (0), "R" (*uaddr), "Jr" (oparg), "i" (-EFAULT)
: "memory");
The branch at the end of the fixup code, it goes back to the SC
instruction, no matter if the fault was first taken by the LL or SC
instruction resulting in an endless loop which will only terminate if
the address become valid again due to another thread setting up an
accessible mapping and the CPU happens to execute the SC instruction
successfully which due to the preceeding ERET instruction of the fault
handler would only happen if UNPREDICTABLE instruction behaviour of the
SC instruction without a preceeding LL happens to favor that outcome.
But normally processes are nice, pass valid arguments and we were just
getting away with this.
Thanks to Kaz Kylheku <kaz@zeugmasystems.com> for providing the original
report and a test case.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
None of weakly ordered processor supported in tree need this but it seems like this could change ... Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Introduce pagefault_{disable,enable}() and use these where previously we did
manual preempt increments/decrements to make the pagefault handler do the
atomic thing.
Currently they still rely on the increased preempt count, but do not rely on
the disabled preemption, this might go away in the future.
(NOTE: the extra barrier() in pagefault_disable might fix some holes on
machines which have too many registers for their own good)
[heiko.carstens@de.ibm.com: s390 fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Also the R4000 / R4600 LL/SC instructions imply a sync so no explicit sync needed. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* git://git.infradead.org/hdrcleanup-2.6: (63 commits) [S390] __FD_foo definitions. Switch to __s32 types in joystick.h instead of C99 types for consistency. Add <sys/types.h> to headers included for userspace in <linux/input.h> Move inclusion of <linux/compat.h> out of user scope in asm-x86_64/mtrr.h Remove struct fddi_statistics from user view in <linux/if_fddi.h> Move user-visible parts of drivers/s390/crypto/z90crypt.h to include/asm-s390 Revert include/media changes: Mauro says those ioctls are only used in-kernel(!) Include <linux/types.h> and use __uXX types in <linux/cramfs_fs.h> Use __uXX types in <linux/i2o_dev.h>, include <linux/ioctl.h> too Remove private struct dx_hash_info from public view in <linux/ext3_fs.h> Include <linux/types.h> and use __uXX types in <linux/affs_hardblocks.h> Use __uXX types in <linux/divert.h> for struct divert_blk et al. Use __u32 for elf_addr_t in <asm-powerpc/elf.h>, not u32. It's user-visible. Remove PPP_FCS from user view in <linux/ppp_defs.h>, remove __P mess entirely Use __uXX types in user-visible structures in <linux/nbd.h> Don't use 'u32' in user-visible struct ip_conntrack_old_tuple. Use __uXX types for S390 DASD volume label definitions which are user-visible S390 BIODASDREADCMB ioctl should use __u64 not u64 type. Remove unneeded inclusion of <linux/time.h> from <linux/ufs_fs.h> Fix private integer types used in V4L2 ioctls. ... Manually resolve conflict in include/linux/mtd/physmap.h
I found that NPTL's pthread_cond_signal() does not work properly on kernels compiled by gcc 4.1.x. I suppose inline asm for __futex_atomic_op() was wrong. I suppose: 1. "=&r" constraint should be used for oldval. 2. Instead of "r" (uaddr), "=R" (*uaddr) for output and "R" (*uaddr) for input should be used. 3. "memory" should be added to the clobber list. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
o Implement futex_atomic_op_inuser() operation
o Don't use the R10000-ll/sc bug workaround version for every processor.
branch likely is deprecated and some historic ll/sc processors don't
implement it. In any case it's slow.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>