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  1. 11 Mar, 2012 4 commits
    • Martin Schwidefsky's avatar
      [S390] rework idle code · 4c1051e3
      Martin Schwidefsky authored 
      Whenever the cpu loads an enabled wait PSW it will appear as idle to the
underlying host system. The code in default_idle calls vtime_stop_cpu
which does the necessary voodoo to get the cpu time accounting right.
The udelay code just loads an enabled wait PSW. To correct this rework
the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts
to entry[64].S, vtime_stop_cpu can now be called from anywhere and
vtime_start_cpu is gone. The correction of the cpu time during wakeup
from an enabled wait PSW is done with a critical section in entry[64].S.
As vtime_start_cpu is gone, s390_idle_check can be removed as well.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      4c1051e3
    • Martin Schwidefsky's avatar
      [S390] rework smp code · 8b646bd7
      Martin Schwidefsky authored 
      Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.

The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.

Overall the code is now simpler and there are ~380 lines less code.
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      8b646bd7
    • Martin Schwidefsky's avatar
      [S390] rename lowcore field · 7e180bd8
      Martin Schwidefsky authored 
      The 16 bit value at the lowcore location with offset 0x84 is the
cpu address that is associated with an external interrupt. Rename
the field from cpu_addr to ext_cpu_addr to make that clear.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      7e180bd8
    • Michael Holzheu's avatar
      [S390] Fix gcc 4.6.0 compile warning · 4fdf7f43
      Michael Holzheu authored 
      With gcc 4.6.0 we get a false compile warning:

 arch/s390/kernel/setup.c: In function 'setup_arch':
 arch/s390/kernel/setup.c:767:3: warning: 'msg' may be used
            uninitialized in this function [-Wuninitialized]
 arch/s390/kernel/setup.c:753:8: note: 'msg' was declared here

This patch makes gcc quiet.
Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      4fdf7f43
  3. 10 Mar, 2012 4 commits
    • Linus Torvalds's avatar
      Linux 3.3-rc7 · fde7d904
      Linus Torvalds authored
      fde7d904
    • Al Viro's avatar
      aio: fix the "too late munmap()" race · c7b28555
      Al Viro authored 
      Current code has put_ioctx() called asynchronously from aio_fput_routine();
that's done *after* we have killed the request that used to pin ioctx,
so there's nothing to stop io_destroy() waiting in wait_for_all_aios()
from progressing.  As the result, we can end up with async call of
put_ioctx() being the last one and possibly happening during exit_mmap()
or elf_core_dump(), neither of which expects stray munmap() being done
to them...

We do need to prevent _freeing_ ioctx until aio_fput_routine() is done
with that, but that's all we care about - neither io_destroy() nor
exit_aio() will progress past wait_for_all_aios() until aio_fput_routine()
does really_put_req(), so the ioctx teardown won't be done until then
and we don't care about the contents of ioctx past that point.

Since actual freeing of these suckers is RCU-delayed, we don't need to
bump ioctx refcount when request goes into list for async removal.
All we need is rcu_read_lock held just over the ->ctx_lock-protected
area in aio_fput_routine().
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Reviewed-by: default avatarJeff Moyer <jmoyer@redhat.com>
Acked-by: default avatarBenjamin LaHaise <bcrl@kvack.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c7b28555
    • Al Viro's avatar
      aio: fix io_setup/io_destroy race · 86b62a2c
      Al Viro authored 
      Have ioctx_alloc() return an extra reference, so that caller would drop it
on success and not bother with re-grabbing it on failure exit.  The current
code is obviously broken - io_destroy() from another thread that managed
to guess the address io_setup() would've returned would free ioctx right
under us; gets especially interesting if aio_context_t * we pass to
io_setup() points to PROT_READ mapping, so put_user() fails and we end
up doing io_destroy() on kioctx another thread has just got freed...
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Acked-by: default avatarBenjamin LaHaise <bcrl@kvack.org>
Reviewed-by: default avatarJeff Moyer <jmoyer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      86b62a2c
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs · 86e06008
      Linus Torvalds authored 
      Pull btrfs updates from Chris Mason:
 "I have two additional and btrfs fixes in my for-linus branch.  One is
  a casting error that leads to memory corruption on i386 during scrub,
  and the other fixes a corner case in the backref walking code (also
  triggered by scrub)."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix casting error in scrub reada code
  btrfs: fix locking issues in find_parent_nodes()
      86e06008
  5. 09 Mar, 2012 14 commits
  7. 08 Mar, 2012 16 commits
  9. 07 Mar, 2012 2 commits
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