- 18 Jun, 2009 40 commits
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Matt Helsley authored
Strictly speaking list_op_pending points to the 'lock entry', not the 'lock word' (which is actually at 'offset' from 'lock entry'). We can infer this based on reading the code in kernel/futex.c: struct robust_list __user *entry, *next_entry, *pending; ... if (fetch_robust_entry(&pending, &head->list_op_pending, &pip)) return; ... if (pending) handle_futex_death((void __user *)pending + futex_offset, curr, pip); Which is also consistent with the rest of the docs on robust futex lists. Signed-off-by:Matt Helsley <matthltc@us.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linuxtronix.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Alexey Dobriyan authored
Function is really private to ipc/ and avoid struct kern_ipc_perm forward declaration. Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by:
WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
Signed-off-by:
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Alexey Dobriyan authored
clone_nsproxy() does useless copying of old nsproxy -- every pointer will be rewritten to new ns or to old ns. Remove copying, rename clone_nsproxy(), create_nsproxy() will be used by C/R code to create fresh nsproxy on restart. Signed-off-by:
Serge Hallyn <serue@us.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
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Alexey Dobriyan authored
clone_ipc_ns() is misnamed, it doesn't clone anything and doesn't use passed parameter. Rename it. create_ipc_ns() will be used by C/R to create fresh ipcns. Signed-off-by:
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Alexey Dobriyan authored
copy_ipcs() doesn't actually copy anything. If new ipcns is created, it's created from scratch, in this case get/put on old ipcns isn't needed. Signed-off-by:
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Alexey Dobriyan authored
create_uts_ns() will be used by C/R to create fresh uts_ns. Signed-off-by:
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Alexey Dobriyan authored
copy_pid_ns() is a perfect example of a case where unwinding leads to more code and makes it less clear. Watch the diffstat. Signed-off-by:
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Reviewed-by:
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Alexey Dobriyan authored
create_pid_namespace() creates everything, but caller has to assign parent pidns by hand, which is unnatural. At the moment of call new ->level has to be taken from somewhere and parent pidns is already available. Signed-off-by:
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Christoph Hellwig authored
find_task_by_pid_type_ns is only used to implement find_task_by_vpid and find_task_by_pid_ns, but both of them pass PIDTYPE_PID as first argument. So just fold find_task_by_pid_type_ns into find_task_by_pid_ns and use find_task_by_pid_ns to implement find_task_by_vpid. While we're at it also remove the exports for find_task_by_pid_ns and find_task_by_vpid - we don't have any modular callers left as the only modular caller of he old pre pid namespace find_task_by_pid (gfs2) was switched to pid_task which operates on a struct pid pointer instead of a pid_t. Given the confusion about pid_t values vs namespace that's generally the better option anyway and I think we're better of restricting modules to do it that way. Signed-off-by:
Christoph Hellwig <hch@lst.de> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Sukanto Ghosh authored
Remoce the unused variable 'val' from __do_proc_dointvec() The integer has been declared and used as 'val = -val' and there is no reference to it anywhere. Signed-off-by:
Sukanto Ghosh <sukanto.cse.iitb@gmail.com> Cc: Jaswinder Singh Rajput <jaswinder@kernel.org> Cc: Sukanto Ghosh <sukanto.cse.iitb@gmail.com> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by:
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Michael Buesch authored
One of my programs frequently grabs the parport, does something with it and then drops it again. This results in spamming of the kernel log with "... registered pardevice" "... unregistered pardevice" These messages are completely useless, except for debugging ppdev, probably. So put them under DEBUG (or dynamic debug). Signed-off-by:
Michael Buesch <mb@bu3sch.de> Signed-off-by:
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Jiri Slaby authored
Fix this: isicom.c: In function `isicom_probe': isicom.c:1587: warning: `signature' may be used uninitialized in this function by uninitialized_var(), because if the signature is not initialized in reset_card(), we won't use it. Signed-off-by:
Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by:
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Adriano dos Santos Fernandes authored
memory_open() ignores devlist and does a switch for each item, duplicating code and conditional definitions. Clean it up by adding backing_dev_info to devlist and use it to lookup for the minor device. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Adriano dos Santos Fernandes <adrianosf@uol.com.br> Signed-off-by:
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Arnd Bergmann authored
The definition of ipc_parse_version depends on __ARCH_WANT_IPC_PARSE_VERSION, but the header file declares it conditionally based on the architecture. Use the macro consistently to make it easier to add new architectures. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
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Oleg Nesterov authored
Now that kthread_stop() can be used even if the task has already exited, we can kill the "wait_to_die:" loop in migration_thread(). But we must pin rq->migration_thread after creation. Actually, I don't think CPU_UP_CANCELED or CPU_DEAD should wait for ->migration_thread exit. Perhaps we can simplify this code a bit more. migration_call() can set ->should_stop and forget about this thread. But we need a new helper in kthred.c for that. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Vitaliy Gusev <vgusev@openvz.org Signed-off-by:
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Oleg Nesterov authored
Based on Eric's patch which in turn was based on my patch. kthread_stop() has the nasty problems: - it runs unpredictably long with the global semaphore held. - it deadlocks if kthread itself does kthread_stop() before it obeys the kthread_should_stop() request. - it is not useable if kthread exits on its own, see for example the ugly "wait_to_die:" hack in migration_thread() - it is not possible to just tell kthread it should stop, we must always wait for its exit. With this patch kthread() allocates all neccesary data (struct kthread) on its own stack, globals kthread_stop_xxx are deleted. ->vfork_done is used as a pointer into "struct kthread", this means kthread_stop() can easily wait for kthread's exit. Signed-off-by:
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Oleg Nesterov authored
We use two completions two create the kernel thread, this is a bit ugly. kthread() wakes up create_kthread() via ->started, then create_kthread() wakes up the caller kthread_create() via ->done. But kthread() does not need to wait for kthread(), it can just return. Instead kthread() itself can wake up the caller of kthread_create(). Kill kthread_create_info->started, ->done is enough. This improves the scalability a bit and sijmplifies the code. The only problem if kernel_thread() fails, in that case create_kthread() must do complete(&create->done). Signed-off-by:
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Richard Kennedy authored
Reorder struct wait_opts to remove 8 bytes of alignment padding on 64 bit builds. Signed-off-by:
Richard Kennedy <richard@rsk.demon.co.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by:
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Oleg Nesterov authored
do_wait: current->state = TASK_INTERRUPTIBLE; read_lock(&tasklist_lock); ... search for the task to reap ... In theory, the ->state changing can leak into the critical section. Since the child can change its status under read_lock(tasklist) in parallel (finish_stop/ptrace_stop), we can miss the wakeup if __wake_up_parent() sees us in TASK_RUNNING state. Add the barrier. Also, use __set_current_state() to set TASK_RUNNING. Signed-off-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
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Oleg Nesterov authored
do_wait() does BUG_ON(tsk->signal != current->signal), this looks like a raher obsolete check. At least, I don't think do_wait() is the best place to verify that all threads have the same ->signal. Remove it. Also, change the code to use while_each_thread(). Signed-off-by:
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Oleg Nesterov authored
Now that we don't pass &retval down to other helpers we can simplify the code more. - kill tsk_result, just use retval - add the "notask" label right after the main loop, and s/got end/goto notask/ after the fastpath pid check. This way we don't need to initialize retval before this check and the code becomes a bit more clean, if this pid has no attached tasks we should just skip the list search. Signed-off-by:
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Oleg Nesterov authored
Introduce "struct wait_opts" which holds the parameters for misc helpers in do_wait() pathes. This adds 13 lines to kernel/exit.c, but saves 256 bytes from .o and imho makes the code much more readable. This patch temporary uglifies rusage/siginfo code a little bit, will be addressed by further cleanups. Signed-off-by:
Ingo Molnar <mingo@elte.hu> Acked-by:
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Oleg Nesterov authored
No functional changes, preparation for the next patch. ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped() which should always accept the stopped tracee, even if do_wait() was called without WUNTRACED. Change wait_task_stopped() to check "ptrace || WUNTRACED" instead. This makes the code more explicit, and "int options" argument becomes const in do_wait() pathes. Signed-off-by:
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Oleg Nesterov authored
In theory it is not safe to dereference ->parent/real_parent without tasklist or rcu lock, we can race with re-parenting. Signed-off-by:
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Oleg Nesterov authored
The forked child can have TIF_SIGPENDING if it was copied from parent's ti->flags. But this is harmless and actually almost never happens, because copy_process() can't succeed if signal_pending() == T. Signed-off-by:
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Oleg Nesterov authored
There is no reason for thread_group_cputime() in wait_task_zombie(), there must be no other threads. This call was previously needed to collect the per-cpu data which we do not have any longer. Signed-off-by:
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Oleg Nesterov authored
Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand() without tasklist_lock. Perhaps it makes sense to make a single helper with "bool rw" argument. Signed-off-by:
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Oleg Nesterov authored
If the non-traced sub-thread calls do_notify_parent_cldstop(), we send the notification to group_leader->real_parent and we report group_leader's pid. But, if group_leader is traced we use the wrong ->parent->nsproxy->pid_ns, the tracer and parent can live in different namespaces. Change the code to use "parent" instead of tsk->parent. Signed-off-by:
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Oleg Nesterov authored
Change wait_task_zombie() to use ->real_parent instead of ->parent. We could even use current afaics, but ->real_parent is more clean. We know that the child is not ptrace_reparented() and thus they are equal. But we should avoid using task_struct->parent, we are going to remove it. Signed-off-by:
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Oleg Nesterov authored
- Use rcu_read_lock() instead of tasklist_lock to find/get the task in ptrace_get_task_struct(). - Make it static, it has no callers outside of ptrace.c. - The comment doesn't match the reality, this helper does not do any checks. Beacuse it is really trivial and static I removed the whole comment. Signed-off-by:
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Oleg Nesterov authored
Remove the "Nasty, nasty" lock dance in ptrace_attach()/ptrace_traceme() - from now task_lock() has nothing to do with ptrace at all. With the recent changes nobody uses task_lock() to serialize with ptrace, but in fact it was never needed and it was never used consistently. However ptrace_attach() calls __ptrace_may_access() and needs task_lock() to pin task->mm for get_dumpable(). But we can call __ptrace_may_access() before we take tasklist_lock, ->cred_exec_mutex protects us against do_execve() path which can change creds and MMF_DUMP* flags. (ugly, but we can't use ptrace_may_access() because it hides the error code, so we have to take task_lock() and use __ptrace_may_access()). NOTE: this change assumes that LSM hooks, security_ptrace_may_access() and security_ptrace_traceme(), can be called without task_lock() held. Signed-off-by:
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Oleg Nesterov authored
ptrace_attach() and ptrace_traceme() are the last functions which look as if the untraced task can have task->ptrace != 0, this must not be possible. Change the code to just check ->ptrace != 0 and s/|=/=/ to set PT_PTRACED. Also, a couple of trivial whitespace cleanups in ptrace_attach(). And move ptrace_traceme() up near ptrace_attach() to keep them close to each other. Signed-off-by:
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Oleg Nesterov authored
- Add PF_KTHREAD check to prevent attaching to the kernel thread with a borrowed ->mm. With or without this change we can race with daemonize() which can set PF_KTHREAD or clear ->mm after ptrace_attach() does the check, but this doesn't matter because reparent_to_kthreadd() does ptrace_unlink(). - Kill "!task->mm" check. We don't really care about ->mm != NULL, and the task can call exit_mm() right after we drop task_lock(). What we need is to make sure we can't attach after exit_notify(), check task->exit_state != 0 instead. Also, move the "already traced" check down for cosmetic reasons. Signed-off-by:
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Oleg Nesterov authored
No functional changes. - Nobody except ptrace.c & co should use ptrace flags directly, we have task_ptrace() for that. - No need to specially check PT_PTRACED, we must not have other PT_ bits set without PT_PTRACED. And no need to know this flag exists. Signed-off-by:
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Oleg Nesterov authored
tracehook_unsafe_exec() doesn't need task_lock(), remove the old comment. Signed-off-by:
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Oleg Nesterov authored
"Search in the siblings" should use ->real_parent, not ->parent. If the task is traced then ->parent == tracer, while the task's parent is always ->real_parent. Signed-off-by:
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Oleg Nesterov authored
m32r: PTRACE_SINGLESTEP sets PT_DTRACE, it is never used except cleared after do_execve(). Signed-off-by:
Hirokazu Takata <takata@linux-m32r.org> Acked-by:
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Oleg Nesterov authored
m68k sets PT_DTRACE in trap_c() but never uses it. Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Acked-by:
Greg Ungerer <gerg@snapgear.com> Cc: Roman Zippel <zippel@linux-m68k.org> Acked-by:
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Oleg Nesterov authored
avr32, mn10300, parisc, s390, sh, xtensa: They never set PT_DTRACE, but clear it after do_execve(). Signed-off-by:
Kyle McMartin <kyle@mcmartin.ca> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: Matthew Wilcox <matthew@wil.cx> Acked-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by:
Paul Mundt <lethal@linux-sh.org> Acked-by:
Chris Zankel <chris@zankel.net> Acked-by:
Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Signed-off-by:
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