- 10 Nov, 2009 2 commits
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Andrew Morton authored
#252: FILE: fs/direct-io.c:1212: + if (end > isize ) total: 1 errors, 0 warnings, 338 lines checked ./patches/direct-io-cleanup-blockdev_direct_io-locking.patch has style problems, please review. If any of these errors are false positives report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Christoph Hellwig authored
different locking types and very confusing checks for some of them. The most complicated one is DIO_OWN_LOCKING for reads, which happens to not actually be used. This patch gets rid of the DIO_OWN_LOCKING - as mentioned above the read case is unused anyway, and the write side is almost identical to DIO_NO_LOCKING. The difference is that DIO_NO_LOCKING always sets the create argument for the get_blocks callback to zero, but we can easily move that to the actual get_blocks callbacks. There are four users of the DIO_NO_LOCKING mode: gfs already ignores the create argument and thus is fine with the new version, ocfs2 only errors out if create were ever set, and we can remove this dead code now, the block device code only ever uses create for an error message if we are fully beyond the device which can never happen, and last but not least XFS will need the new behavour for writes. Now we can replace the lock_type variable with a flags one, where no flag means the DIO_NO_LOCKING behaviour and DIO_LOCKING is kept as the first flag. Separate out the check for not allowing to fill holes into a separate flag, although for now both flags always get set at the same time. Also revamp the documentation of the locking scheme to actually make sense. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alex Elder <aelder@sgi.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 30 Oct, 2009 2 commits
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Andrew Morton authored
Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Jeff Moyer authored
commit 848c4dd5 Author: Zach Brown <zach.brown@oracle.com> Date: Mon Aug 20 17:12:01 2007 -0700 dio: zero struct dio with kzalloc instead of manually This patch uses kzalloc to zero all of struct dio rather than manually trying to track which fields we rely on being zero. It passed aio+dio stress testing and some bug regression testing on ext3. This patch was introduced by Linus in the conversation that lead up to Badari's minimal fix to manually zero .map_bh.b_state in commit: 6a648fa7 It makes the code a bit smaller. Maybe a couple fewer cachelines to load, if we're lucky: text data bss dec hex filename 3285925 568506 1304616 5159047 4eb887 vmlinux 3285797 568506 1304616 5158919 4eb807 vmlinux.patched I was unable to measure a stable difference in the number of cpu cycles spent in blockdev_direct_IO() when pushing aio+dio 256K reads at ~340MB/s. So the resulting intent of the patch isn't a performance gain but to avoid exposing ourselves to the risk of finding another field like .map_bh.b_state where we rely on zeroing but don't enforce it in the code. Zach surmised that zeroing out the page array was what caused most of the problem, and suggested the approach taken in the attached patch for resolving the issue. Intel re-tested with this patch and saw a 0.6% performance gain (the original regression was 0.5%). Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 13 Nov, 2009 2 commits
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Shaohua Li authored
Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joe Perches authored
Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 14 Oct, 2009 1 commit
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Roel Kluin authored
Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 09 Nov, 2009 1 commit
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Jan Beulich authored
comparison msut also be done using the last valid of the buffer in question. Also fix the open-coded instances in lib/swiotlb.c. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Becky Bruce <beckyb@kernel.crashing.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 30 Sep, 2009 3 commits
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Nils Carlson authored
the patch as far as possible with correctible errors and things appear good. The DIMM mapping is correct for our board, but boards may differ. Signed-off-by: Nils Carlson <nils.carlson@ludd.ltu.se> Acked-by: Arthur Jones <ajones@riverbed.com> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nils Carlson authored
scrubbing rate, which is not constant but dependent on memory load. The rate returned by this driver is an estimate based on some experimentation, but is substantially closer to the truth than the speed supplied in the documentation. Also, scrubbing is done once, and then a done-bit is set. This means that to accomplish continuous scrubbing a re-enabling mechanism must be used. I have created the simplest possible such mechanism in the form of a work-queue which will check every five minutes. This interval is quite arbitrary but should be sufficient for all sizes of system memory. Signed-off-by: Nils Carlson <nils.carlson@ludd.ltu.se> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nils Carlson authored
places, this is simply a cleanup of the patch. Signed-off-by: Nils Carlson <nils.carlson@ludd.ltu.se> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 13 Nov, 2009 2 commits
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Karel Zak authored
allocated for the header. The HeaderSize field must be greater than 92 (= sizeof(struct gpt_header) and must be less than or equal to the logical block size. It means we have to read whole sector with the header, because the header crc32 checksum is calculated according to HeaderSize. For more details see UEFI standard (version 2.3, May 2009): - 5.3.1 GUID Format overview, page 93 - Table 13. GUID Partition Table Header, page 96 Signed-off-by: Karel Zak <kzak@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Karel Zak authored
That's wrong. UEFI standard (version 2.3, May 2009, 5.3.1 GUID Format overview, page 95) defines that LBA is always based on the logical block size. It means bdev_logical_block_size() (aka BLKSSZGET) for Linux. This patch removes static sector size from EFI GPT parser. The problem is reproducible with the latest GNU Parted: # modprobe scsi_debug dev_size_mb=50 sector_size=4096 # ./parted /dev/sdb print Model: Linux scsi_debug (scsi) Disk /dev/sdb: 52.4MB Sector size (logical/physical): 4096B/4096B Partition Table: gpt Number Start End Size File system Name Flags 1 24.6kB 3002kB 2978kB primary 2 3002kB 6001kB 2998kB primary 3 6001kB 9003kB 3002kB primary # blockdev --rereadpt /dev/sdb # dmesg | tail -1 sdb: unknown partition table <---- !!! with this patch: # blockdev --rereadpt /dev/sdb # dmesg | tail -1 sdb: sdb1 sdb2 sdb3 Signed-off-by: Karel Zak <kzak@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 12 Nov, 2009 1 commit
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Rakib Mullick authored
!MODULE. So, #ifdef MODULE becomes obsolete. Also move the declaration moxa_board_conf at the start of the function, since we were hit by the following warning. drivers/char/moxa.c: In function `moxa_init': drivers/char/moxa.c:1040: warning: ISO C90 forbids mixed declarations and code Signed-off-by: Rakib Mullick<rakib.mullick@gmail.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 16 Oct, 2009 1 commit
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Roel Kluin authored
Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 09 Oct, 2009 1 commit
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Joe Perches authored
Convert printks to pr_<level> Convert some embedded function names to %s...__func__ Remove a period after exclamation points. Remove #define pr_dbg which could be used by future kernel.h includes Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 30 Sep, 2009 1 commit
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Jiri Slaby authored
tty is dereferenced earlier, the test is superfluous. Remove it. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Greg KH <greg@kroah.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 24 Aug, 2009 1 commit
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Bartlomiej Zolnierkiewicz authored
Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 09 Nov, 2009 1 commit
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Christoph Hellwig authored
USE_ELF_CORE_DUMP. The microblaze omission seems like an error to me, so let's kill this ifdef and make sure we are the same everywhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <linux-arch@vger.kernel.org> Cc: Michal Simek <michal.simek@petalogix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 29 Sep, 2009 1 commit
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Julia Lawall authored
constants ending in _STATE are compared to the state variable. Signed-off-by: Julia Lawall <julia@diku.dk> Cc: Corey Minyard <minyard@acm.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 09 Nov, 2009 7 commits
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Manfred Spraul authored
current code scans all decrement operations, even if the semaphore value is already 0. The patch optimizes that: if the semaphore value is 0, then there is no need to scan the q->alter entries. Note that this is a common case: It happens if 100 decrements by one are pending and now an increment by one increases the semaphore value from 0 to 1. Without this patch, all 100 entries are scanned. With the patch, only one entry is scanned, then woken up. Then the new rule triggers and the scanning is aborted, without looking at the remaining 99 tasks. With this patch, single sop increment/decrement by 1 are now O(1). (same as with Nick's patch) Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Manfred Spraul authored
semaphores. Atomic operations that affect multiple semaphores are supported. The patch optimizes single semaphore operation calls that affect only one semaphore: It's not necessary to scan all pending operations, it is sufficient to scan the per-semaphore list. The idea is from Nick Piggin version of an ipc sem improvement, the implementation is different: The code tries to keep as much common code as possible. As the result, the patch is simpler, but optimizes fewer cases. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Manfred Spraul authored
sysv sem has the concept of semaphore arrays that consist out of multiple semaphores. Atomic operations that affect multiple semaphores are supported. The patch is the first step for optimizing simple, single semaphore operations: In addition to the global list of all pending operations, a 2nd, per-semaphore list with the simple operations is added. Note: this patch does not make sense by itself, the new list is used nowhere. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Manfred Spraul authored
If try_atomic_semop failed, then no changes were applied. Thus no need to restart. Additionally, this patch correct an incorrect comment: It's possible to wait for arbitrary semaphore values (do a dec by <x>, wait-for-zero, inc by <x> in one atomic operation) Both changes are from Nick Piggin, the patch is the result of a different split of the individual changes. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nick Piggin authored
involved, which could deadlock if preemption is enabled during the "lock". It is an implementation detail (due to a spinlock being held) that this is actually the case. However if "spinlocks" are made preemptible, or if the sem lock is changed to a sleeping lock for example, then the wakeup would become buggy. So this might be a bugfix for -rt kernels. Imagine waker being preempted by wakee and never clearing IN_WAKEUP -- if wakee has higher RT priority then there is a priority inversion deadlock. Even if there is not a priority inversion to cause a deadlock, then there is still time wasted spinning. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nick Piggin authored
list_for_each_entry macros. list_for_each_entry_safe() must be used, because list entries can disappear immediately uppon the wakeup event. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nick Piggin authored
sysv sem algorithm: Most (at least: some important) users only use simple semaphore operations, therefore it's worthwile to optimize this use case. This patch: Move last looked up sem_undo struct to the head of the task's undo list. Attempt to move common entries to the front of the list so search time is reduced. This reduces lookup_undo on oprofile of problematic SAP workload by 30% (see patch 4 for a description of SAP workload). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 13 Oct, 2009 1 commit
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Serge E. Hallyn authored
7ca7e564 "ipc: store ipcs into IDRs" in 2007. The idr of which 3 exist for each ipc namespace is never freed. This patch simply frees them when the ipcns is freed. I don't believe any idr_remove() are done from rcu (and could therefore be delayed until after this idr_destroy()), so the patch should be safe. Some quick testing showed no harm, and the memory leak fixed. Caught by kmemleak. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 09 Nov, 2009 1 commit
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Oleg Nesterov authored
Currently we add sub-threads to ->real_parent->children list. This buys nothing but slows down do_wait(). With this patch ->children contains only main threads (group leaders). The only complication is that forget_original_parent() should iterate over sub-threads by hand, and de_thread() needs another list_replace() when it changes ->group_leader. Henceforth do_wait_thread() can never see task_detached() && !EXIT_DEAD tasks, we can remove this check (and we can unify do_wait_thread() and ptrace_do_wait()). This change can confuse the optimistic search in mm_update_next_owner(), but this is fixable and minor. Perhaps badness() and oom_kill_process() should be updated, but they should be fixed in any case. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ratan Nalumasu <rnalumasu@gmail.com> Cc: Vitaly Mayatskikh <vmayatsk@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 30 Oct, 2009 1 commit
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Oleg Nesterov authored
->group_stop_count condition visible to tracers before do_signal_stop() will participate in this group-stop. Currently the patch has no effect, tracehook_get_signal() always returns 0. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 16 Oct, 2009 3 commits
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Oleg Nesterov authored
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
This is a bit confusing, we don't know the source of this signal. But we don't care, and "info->si_code = 0" is imho worse. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
triggers the "from_ancestor_ns" check. This fixes reparent_thread()->group_send_sig_info(pdeath_signal) behaviour, before this patch send_signal() does not detect the cross-namespace case when the child of the dying parent belongs to the sub-namespace. This patch can affect the behaviour of send_sig(), kill_pgrp() and kill_pid() when the caller sends the signal to the sub-namespace with "priv == 0" but surprisingly all callers seem to use them correctly, including disassociate_ctty(on_exit). Except: drivers/staging/comedi/drivers/addi-data/*.c incorrectly use send_sig(priv => 0). But his is minor and should be fixed anyway. Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 11 Nov, 2009 1 commit
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Oleg Nesterov authored
and changes check_kill_permission() to use this helper. The real effect of this patch is that from now we "officially" consider SEND_SIG_NOINFO signal as "from user-space" signals. This is already true if we look at the code which uses SEND_SIG_NOINFO, except __send_signal() has another opinion - see the next patch. The naming of these special SEND_SIG_XXX siginfo's is really bad imho. From __send_signal()'s pov they mean SEND_SIG_NOINFO from user SEND_SIG_PRIV from kernel SEND_SIG_FORCED no info Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 12 Nov, 2009 5 commits
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Oleg Nesterov authored
Unlike powepc, x86 always calls tracehook_report_syscall_exit(step) with step = 0, and sends the trap by hand. This results in unnecessary SIGTRAP when PTRACE_SINGLESTEP follows the syscall-exit stop. Change syscall_trace_leave() to pass the correct "step" argument to tracehook and remove the send_sigtrap() logic. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
Implement user_single_step_siginfo() for x86. Extract this code from send_sigtrap(). Since x86 calls tracehook_report_syscall_exit(step => 0) the new helper is not used yet. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
Change tracehook_report_syscall_exit() to look at step flag and send the trap signal if needed. This change affects ia64, microblaze, parisc, powerpc, sh. They pass nonzero "step" argument to tracehook but since it was ignored the tracee reports via ptrace_notify(), this is not right and not consistent. - PTRACE_SETSIGINFO doesn't work - if the tracer resumes the tracee with signr != 0 the new signal is generated rather than delivering it - If PT_TRACESYSGOOD is set the tracee reports the wrong exit_code I don't have a powerpc machine, but I think this test-case should see the difference: #include <unistd.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <assert.h> #include <stdio.h> int main(void) { int pid, status; if (!(pid = fork())) { assert(ptrace(PTRACE_TRACEME) == 0); kill(getpid(), SIGSTOP); getppid(); return 0; } assert(pid == wait(&status)); assert(ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACESYSGOOD) == 0); assert(ptrace(PTRACE_SYSCALL, pid, 0,0) == 0); assert(pid == wait(&status)); assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0); assert(pid == wait(&status)); if (status == 0x57F) return 0; printf("kernel bug: status=%X shouldn't have 0x80\n", status); return 1; } Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
Implement user_single_step_siginfo() for powerpc. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
Currently there is no way to synthesize a single-stepping trap in the arch-independent manner. This patch adds the default helper which fills siginfo_t, arch/ can can override it. Architetures which implement user_enable_single_step() should add user_single_step_siginfo() also. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 11 Nov, 2009 1 commit
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Oleg Nesterov authored
starts with TIF_SINGLESTEP/X86_EFLAGS_TF bits copied from ptraced parent. This is not right, especially when the new child is not auto-attaced: in this case it is killed by SIGTRAP. Change copy_process() to call user_disable_single_step(). Tested on x86. Test-case: #include <stdio.h> #include <unistd.h> #include <signal.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <assert.h> int main(void) { int pid, status; if (!(pid = fork())) { assert(ptrace(PTRACE_TRACEME) == 0); kill(getpid(), SIGSTOP); if (!fork()) { /* kernel bug: this child will be killed by SIGTRAP */ printf("Hello world\n"); return 43; } wait(&status); return WEXITSTATUS(status); } for (;;) { assert(pid == wait(&status)); if (WIFEXITED(status)) break; assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0); } assert(WEXITSTATUS(status) == 43); return 0; } Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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