- 02 Oct, 2006 40 commits
-
-
Greg Banks authored
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Greg Banks authored
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Greg Banks authored
cpumask: ensure that node_to_cpumask() is available to modules for all supported combinations of architecture and CONFIG_NUMA. Signed-off-by: Greg Banks <gnb@melbourne.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Greg Banks authored
cpumask: ensure that the cpu_online_map and cpu_possible_map bitmasks, and hence all the macros in <linux/cpumask.h> that require them, are available to modules for all supported combinations of architecture and CONFIG_SMP. Signed-off-by: Greg Banks <gnb@melbourne.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Greg Banks authored
cpumask: add highest_possible_node_id(), analogous to highest_possible_processor_id(). [pj@sgi.com: fix typo] Signed-off-by: Greg Banks <gnb@melbourne.sgi.com> Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Andrew Morton authored
As reported in http://bugzilla.kernel.org/show_bug.cgi?id=6970, ISDN can issue excessively-long udelays, which triggers a build-time error on ARM. This is very sucky of ISDN, but I doubt if anyone is going to suddenly fix it. So change the macro to do the microsecond counting itself. Cc: <tch@wpkg.org> Cc: Karsten Keil <kkeil@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Tilman Schmidt authored
This patch to the Siemens Gigaset driver fixes the compile warning "ignoring return value of 'class_device_create_file', declared with attribute warn_unused_result" appearing with CONFIG_ENABLE_MUST_CHECK=y in release 2.6.18-rc1-mm1. Signed-off-by: Tilman Schmidt <tilman@imap.cc> Acked-by: Hansjoerg Lipp <hjlipp@web.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Ankita Garg authored
A simple module to test Linux Kernel Dump mechanism. This module uses jprobes to install/activate pre-defined crash points. At different crash points, various types of crashing scenarios are created like a BUG(), panic(), exception, recursive loop and stack overflow. The user can activate a crash point with specific type by providing parameters at the time of module insertion. Please see the file header for usage information. The module is based on the Linux Kernel Dump Test Tool by Fernando <http://lkdtt.sourceforge.net>. This module could be merged with mainline. Jprobes is used here so that the context in which crash point is hit, could be maintained. This implements all the crash points as done by LKDTT except the one in the middle of tasklet_action(). Signed-off-by: Ankita Garg <ankita@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
bibo,mao authored
kprobe_flush_task() possibly calls kfree function during holding kretprobe_lock spinlock, if kfree function is probed by kretprobe that will incur spinlock deadlock. This patch moves kfree function out scope of kretprobe_lock. Signed-off-by: bibo, mao <bibo.mao@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
bibo,mao authored
When kprobe is re-entered, the re-entered kprobe kernel path will will call atomic_notifier_call_chain function, if this function is kprobed that will incur numerous kprobe recursive fault. This patch disallows kprobes on atomic_notifier_call_chain function. Signed-off-by: bibo, mao <bibo.mao@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
bibo,mao authored
Whitespace is used to indent, this patch cleans up these sentences by kernel coding style. Signed-off-by: bibo, mao <bibo.mao@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Ananth N Mavinakayanahalli authored
Documentation/kprobes.txt updated to reflect: o In-kernel symbol resolution o CONFIG_KALLSYMS dependency o Usage of JPROBE_ENTRY o Addition of regs_return_value() Also update the references list and usage examples to use correct module interfaces. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Ananth N Mavinakayanahalli authored
Add the regs_return_value() macro to extract the return value in an architecture agnostic manner, given the pt_regs. Other architecture maintainers may want to add similar helpers. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Ananth N Mavinakayanahalli authored
kallsyms_lookup_name() allows for <module:symbol> style specification for looking up symbol addresses. Handle the case where the user specifies <module:.symbol> on powerpc, given that 64-bit powerpc uses function descriptors. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Ananth N Mavinakayanahalli authored
In an effort to make kprobe modules more portable, here is a patch that: o Introduces the "symbol_name" field to struct kprobe. The symbol->address resolution now happens in the kernel in an architecture agnostic manner. 64-bit powerpc users no longer have to specify the ".symbols" o Introduces the "offset" field to struct kprobe to allow a user to specify an offset into a symbol. o The legacy mechanism of specifying the kprobe.addr is still supported. However, if both the kprobe.addr and kprobe.symbol_name are specified, probe registration fails with an -EINVAL. o The symbol resolution code uses kallsyms_lookup_name(). So CONFIG_KPROBES now depends on CONFIG_KALLSYMS o Apparantly kprobe modules were the only legitimate out-of-tree user of the kallsyms_lookup_name() EXPORT. Now that the symbol resolution happens in-kernel, remove the EXPORT as suggested by Christoph Hellwig o Modify tcp_probe.c that uses the kprobe interface so as to make it work on multiple platforms (in its earlier form, the code wouldn't work, say, on powerpc) Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Cedric Le Goater authored
Replaces the pid_t value with a struct pid to avoid pid wrap around problems. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
The problem with remembering a user space process by its pid is that it is possible that the process will exit, pid wrap around will occur. Converting to a struct pid avoid that problem, and paves the way for implementing a pid namespace. Also since usb is the only user of kill_proc_info_as_uid rename kill_proc_info_as_uid to kill_pid_info_as_uid and have the new version take a struct pid. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
This has been needed for a long time, but now with the advent of a reference counted struct pid there are real consequences for getting this wrong. Someone I think it was Oleg Nesterov pointed out that this construct was missing locking, when I introduced struct pid. After taking time to review the locking construct already present I figured out which lock needs to be taken. The other paths that access f_owner.pid take either the f_owner read or the write lock. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Cedric Le Goater authored
Message queues can signal a process waiting for a message. This patch replaces the pid_t value with a struct pid to avoid pid wrap around problems. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Acked-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
This updates my proc: readdir race fix (take 3) patch to account for the changes made by: Sukadev Bhattiprolu <sukadev@us.ibm.com> to introduce struct pspace. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Sukadev Bhattiprolu authored
Define a per-container pid space object. And create one instance of this object, init_pspace, to define the entire pid space. Subsequent patches will provide/use interfaces to create/destroy pid spaces. Its a subset/rework of Eric Biederman's patch http://lkml.org/lkml/2006/2/6/285 . Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Kirill Korotaev <dev@sw.ru> Cc: Andrey Savochkin <saw@sw.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Sukadev Bhattiprolu authored
Move struct pidmap and PIDMAP_ENTRIES to a new file, include/linux/pspace.h where it will be used in subsequent patches to define pid spaces. Its a subset of Eric Biederman's patch http://lkml.org/lkml/2006/2/6/285 [akpm@osdl.org: cleanups] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Oleg Nesterov authored
I think it is hardly possible to read the current do_each_task_pid(). The new version is much simpler and makes the code smaller. Only the do_each_task_pid change is tested, the do_each_pid_task isn't. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
Use struct pidmap instead of pidmap_t. This updates my proc: readdir race fix (take 3) patch to account for the changes made by: Sukadev Bhattiprolu <sukadev@us.ibm.com> to kill pidmap_t. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Sukadev Bhattiprolu authored
Use struct pidmap instead of pidmap_t. Its a subset of Eric Biederman's patch http://lkml.org/lkml/2006/2/6/271. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Jeff Dike authored
As part of an SMP cleanliness pass over UML, I consted a bunch of structures in order to not have to document their locking. One of these structures was a struct tty_operations. In order to const it in UML without introducing compiler complaints, the declaration of tty_set_operations needs to be changed, and then all of its callers need to be fixed. This patch declares all struct tty_operations in the tree as const. In all cases, they are static and used only as input to tty_set_operations. As an extra check, I ran an i386 allyesconfig build which produced no extra warnings. 53 drivers are affected. I checked the history of a bunch of them, and in most cases, there have been only a handful of maintenance changes in the last six months. serial_core.c was the busiest one that I looked at. Signed-off-by: Jeff Dike <jdike@addtoit.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Andreas Mohr authored
Only touch inode's i_mtime and i_ctime to make them equal to "now" in case they aren't yet (don't just update timestamp unconditionally). Uninline the hash function to save 259 Bytes. This tiny inode change which may improve cache behaviour also shaves off 8 Bytes from file_update_time() on i386. Included a tiny codestyle cleanup, too. Signed-off-by: Andreas Mohr <andi@lisas.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Alexey Dobriyan authored
Everybody passes valid pointer there. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
File handles can be requested to send sigio and sigurg to processes. By tracking the destination processes using struct pid instead of pid_t we make the interface safe from all potential pid wrap around problems. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
I took a good hard look at the locking and it appears the locking on vt_pid is the console semaphore. Every modified path is called under the console semaphore except reset_vc when it is called from fn_SAK or do_SAK both of which appear to be in interrupt context. In addition I need to be careful because in the presence of an oops the console_sem may be arbitrarily dropped. Which leads me to conclude the current locking is inadequate for my needs. Given the weird cases we could hit because of oops printing instead of introducing an extra spin lock to protect the data and keep the pid to signal and the signal to send in sync, I have opted to use xchg on just the struct pid * pointer instead. Due to console_sem we will stay in sync between vt_pid and vt_mode except for a small window during a SAK, or oops handling. SAK handling should kill any user space process that care, and oops handling we are broken anyway. Besides the worst that can happen is that I try to send the wrong signal. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
This is such a rare path it took me a while to figure out how to test this after soring out the locking. This patch does several things. - The variables used are moved into a structure and declared in vt_kern.h - A spinlock is added so we don't have SMP races updating the values. - Instead of raw pid_t value a struct_pid is used to guard against pid wrap around issues, if the daemon to spawn a new console dies. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
As we stop storing pid_t's and move to storing struct pid *. We need a way to get the pid_t from the struct pid to report to user space what we have stored. Having a clean well defined way to do this is especially important as we move to multiple pid spaces as may need to report a different value to the caller depending on which pid space the caller is in. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
pids aren't something that drivers should care about. However there are a lot of helper layers in the kernel that do care, and are built as modules. Before I can convert them to using struct pid instead of pid_t I need to export the appropriate symbols so they can continue to be built. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
Currently the signal functions all either take a task or a pid_t argument. This patch implements variants that take a struct pid *. After all of the users have been update it is my intention to remove the variants that take a pid_t as using pid_t can be more work (an extra hash table lookup) and difficult to get right in the presence of multiple pid namespaces. There are two kinds of functions introduced in this patch. The are the general use functions kill_pgrp and kill_pid which take a priv argument that is ultimately used to create the appropriate siginfo information, Then there are _kill_pgrp_info, kill_pgrp_info, kill_pid_info the internal implementation helpers that take an explicit siginfo. The distinction is made because filling out an explcit siginfo is tricky, and will be even more tricky when pid namespaces are introduced. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
To avoid pid rollover confusion the kernel needs to work with struct pid * instead of pid_t. Currently there is not an iterator that walks through all of the tasks of a given pid type starting with a struct pid. This prevents us replacing some pid_t instances with struct pid. So this patch adds do_each_pid_task which walks through the set of task for a given pid type starting with a struct pid. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
In the last round of cleaning up the pid hash table a more general struct pid was introduced, that can be referenced counted. With the more general struct pid most if not all places where we store a pid_t we can now store a struct pid * and remove the need for a hash table lookup, and avoid any possible problems with pid roll over. Looking forward to the pid namespaces struct pid * gives us an absolute form a pid so we can compare and use them without caring which pid namespace we are in. This patchset introduces the infrastructure needed to use struct pid instead of pid_t, and then it goes on to convert two different kernel users that currently store a pid_t value. There are a lot more places to go but this is enough to get the basic idea. Before we can merge a pid namespace patch all of the kernel pid_t users need to be examined. Those that deal with user space processes need to be converted to using a struct pid *. Those that deal with kernel processes need to converted to using the kthread api. A rare few that only use their current processes pid values get to be left alone. This patch: task_session returns the struct pid of a tasks session. task_pgrp returns the struct pid of a tasks process group. task_tgid returns the struct pid of a tasks thread group. task_pid returns the struct pid of a tasks process id. These can be used to avoid unnecessary hash table lookups, and to implement safe pid comparisions in the face of a pid namespace. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
Helper functions in base.c like proc_pident_readdir and proc_pident_lookup assume the directories have an associated task, and cannot currently be used on the /proc root directory because it does not have such a task. This small changes allows for base.c to be simplified and later when multiple pid spaces are introduced it makes getting the needed context information trivial. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
Currently proc_pident_lookup gets the names and types from a table and then has a huge switch statement to get the inode and file operations it needs. That is silly and is becoming increasingly hard to maintain so I just put all of the information in the table. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
There were enough changes in my last round of cleaning up proc I had to break up the patch series into smaller chunks, and my last chunk never got resent. This patchset gives proc dynamic inode numbers (the static inode numbers were a pain to maintain and prevent all kinds of things), and removes the horrible switch statements that had to be kept in sync with everything else. Being fully table driver takes us 90% of the way of being able to register new process specific attributes in proc. This patch: Group the functions by what they implement instead of by type of operation. As it existed base.c was quickly approaching the point where it could not be followed. No functionality or code changes asside from adding/removing forward declartions are implemented in this patch. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-
Eric W. Biederman authored
The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-