- 11 Dec, 2014 40 commits
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Linus Torvalds authored
Merge first patchbomb from Andrew Morton: - a few minor cifs fixes - dma-debug upadtes - ocfs2 - slab - about half of MM - procfs - kernel/exit.c - panic.c tweaks - printk upates - lib/ updates - checkpatch updates - fs/binfmt updates - the drivers/rtc tree - nilfs - kmod fixes - more kernel/exit.c - various other misc tweaks and fixes * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) exit: pidns: fix/update the comments in zap_pid_ns_processes() exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting exit: exit_notify: re-use "dead" list to autoreap current exit: reparent: call forget_original_parent() under tasklist_lock exit: reparent: avoid find_new_reaper() if no children exit: reparent: introduce find_alive_thread() exit: reparent: introduce find_child_reaper() exit: reparent: document the ->has_child_subreaper checks exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper() exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting exit: proc: don't try to flush /proc/tgid/task/tgid exit: release_task: fix the comment about group leader accounting exit: wait: drop tasklist_lock before psig->c* accounting exit: wait: don't use zombie->real_parent exit: wait: cleanup the ptrace_reparented() checks usermodehelper: kill the kmod_thread_locker logic usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races ...
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Oleg Nesterov authored
The comments in zap_pid_ns_processes() are not clear, we need to explain how this code actually works. 1. "Ignore SIGCHLD" looks like optimization but it is not, we also need this for correctness. 2. The comment above sys_wait4() could tell more. EXIT_ZOMBIE child is only possible if it has exited before we ignored SIGCHLD. Or if it is traced from the parent namespace, but in this case it will be reaped by debugger after detach, sys_wait4() acts as a synchronization point. 3. The comment about TASK_DEAD (EXIT_DEAD in fact) children is outdated. Contrary to what it says we do not need to make sure they all go away after 0a01f2cc "pidns: Make the pidns proc mount/umount logic obvious". At the same time, we do need to wait for nr_hashed==init_pids, but the reasons are quite different and not obvious: setns(). Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Sterling Alexander <stalexan@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Oleg Nesterov authored
alloc_pid() does get_pid_ns() beforehand but forgets to put_pid_ns() if it fails because disable_pid_allocation() was called by the exiting child_reaper. We could simply move get_pid_ns() down to successful return, but this fix tries to be as trivial as possible. Signed-off-by:
"Eric W. Biederman" <ebiederm@xmission.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Sterling Alexander <stalexan@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Oleg Nesterov authored
After the previous change we can add just the exiting EXIT_DEAD task to the "dead" list and remove another release_task(tsk). Signed-off-by:
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Oleg Nesterov authored
Shift "release dead children" loop from forget_original_parent() to its caller, exit_notify(). It is safe to reap them even if our parent reaps us right after we drop tasklist_lock, those children no longer have any connection to the exiting task. And this allows us to avoid write_lock_irq(tasklist_lock) right after it was released by forget_original_parent(), we can simply call it with tasklist_lock held. While at it, move the comment about forget_original_parent() up to this function. Signed-off-by:
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Oleg Nesterov authored
Now that pid_ns logic was isolated we can change forget_original_parent() to return right after find_child_reaper() when father->children is empty, there is nothing to reparent in this case. In particular this avoids find_alive_thread() and this can help if the whole process exits and it has a lot of PF_EXITING threads at the start of the thread list, this can easily lead to O(nr_threads ** 2) iterations. Trivial test case (tested under KVM, 2 CPUs): static void *tfunc(void *arg) { pause(); return NULL; } static int child(unsigned int nt) { pthread_t pt; while (nt--) assert(pthread_create(&pt, NULL, tfunc, NULL) == 0); pthread_kill(pt, SIGTRAP); pause(); return 0; } int main(int argc, const char *argv[]) { int stat; unsigned int nf = atoi(argv[1]); unsigned int nt = atoi(argv[2]); while (nf--) { if (!fork()) return child(nt); wait(&stat); assert(stat == SIGTRAP); } return 0; } $ time ./test 16 16536 shows: real user sys - 5m37.628s 0m4.437s 8m5.560s + 0m50.032s 0m7.130s 1m4.927s Signed-off-by: -
Oleg Nesterov authored
Add the new simple helper to factor out the for_each_thread() code in find_child_reaper() and find_new_reaper(). It can also simplify the potential PF_EXITING -> exit_state change, plus perhaps we can change this code to take SIGNAL_GROUP_EXIT into account. Signed-off-by:
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Oleg Nesterov authored
find_new_reaper() does 2 completely different things. Not only it finds a reaper, it also updates pid_ns->child_reaper or kills the whole namespace if the caller is ->child_reaper. Now that has_child_subreaper logic doesn't depend on child_reaper check we can move that pid_ns code into a separate helper. IMHO this makes the code more clean, and this allows the next changes. Signed-off-by:
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Oleg Nesterov authored
Swap the "init_task" and same_thread_group() checks. This way it is more simple to document these checks and we can remove the link to the previous discussion on lkml. Signed-off-by:
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Oleg Nesterov authored
Change find_new_reaper() to use for_each_thread() instead of deprecated while_each_thread(). We do not bother to check "thread != father" in the 1st loop, we can rely on PF_EXITING check. Note: this means the minor behavioural change: for_each_thread() starts from the group leader. But this should be fine, nobody should make any assumption about do_wait(__WNOTHREAD) when it comes to reparented tasks. And this can avoid the pointless reparenting to a short-living thread While zombie leaders are not that common. Signed-off-by:
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Oleg Nesterov authored
find_new_reaper() assumes that "has_child_subreaper" logic is safe as long as we are not the exiting ->child_reaper and this is doubly wrong: 1. In fact it is safe if "pid_ns->child_reaper == father"; there must be no children after zap_pid_ns_processes() returns, so it doesn't matter what we return in this case and even pid_ns->child_reaper is wrong otherwise: we can't reparent to ->child_reaper == current. This is not a bug, but this is confusing. 2. It is not safe if we are not pid_ns->child_reaper but from the same thread group. We drop tasklist_lock before zap_pid_ns_processes(), so another thread can lock it and choose the new reaper from the upper namespace if has_child_subreaper == T, and this is obviously wrong. This is not that bad, zap_pid_ns_processes() won't return until the the new reaper reaps all zombies, but this should be fixed anyway. We could change for_each_thread() loop to use ->exit_state instead of PF_EXITING which we had to use until 8aac6270, or we could change copy_signal() to check CLONE_NEWPID before setting has_child_subreaper, but lets change this code so that it is clear we can't look outside of our namespace, otherwise same_thread_group(reaper, child_reaper) check will look wrong and confusing anyway. We can simply start from "father" and fix the problem. We can't wrongly return a thread from the same thread group if ->is_child_subreaper == T, we know that all threads have PF_EXITING set. Signed-off-by:
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Oleg Nesterov authored
The ->has_child_subreaper code in find_new_reaper() finds alive "thread" but returns another "reaper" thread which can be dead. Signed-off-by:
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Oleg Nesterov authored
proc_flush_task_mnt() always tries to flush task/pid, but this is pointless if we reap the leader. d_invalidate() is recursive, and if nothing else the next d_hash_and_lookup(tgid) should fail anyway. Signed-off-by:
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Oleg Nesterov authored
Contrary to what the comment in __exit_signal() says we do account the group leader. Fix this and explain why. Signed-off-by:
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Oleg Nesterov authored
wait_task_zombie() no longer needs tasklist_lock to accumulate the psig->c* counters, we can drop it right after cmpxchg(exit_state). Signed-off-by:
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Oleg Nesterov authored
1. wait_task_zombie() uses p->real_parent to get psig/siglock. This is correct but needs tasklist_lock, ->real_parent can exit. We can use "current" instead. This is our natural child, its parent must be our sub-thread. 2. Read psig/sig outside of ->siglock, ->signal is no longer protected by this lock. 3. Fix the outdated comments about tasklist_lock. We can not race with __exit_signal(), the whole thread group is dead, nobody but us can call it. Also clarify the usage of ->stats_lock and ->siglock. Note: thread_group_cputime_adjusted() is sub-optimal in this case, we probably want to export cputime_adjust() to avoid thread_group_cputime(). The comment says "all threads" but there are no other threads. Signed-off-by:
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Oleg Nesterov authored
Now that EXIT_DEAD is the terminal state we can kill "int traced" variable and check "state == EXIT_DEAD" instead to cleanup the code. In particular, this way it is clear that the check obviously doesn't need tasklist_lock. Also fix the type of "unsigned long state", "long" was always wrong although this doesn't matter because cmpxchg/xchg uses typeof(*ptr). [akpm@linux-foundation.org: don't make me google the C Operator Precedence table] Signed-off-by:
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Oleg Nesterov authored
Now that we do not call kernel_thread(CLONE_VFORK) from the worker thread we can not deadlock if do_execve() in turn triggers another call_usermodehelper(), we can remove the kmod_thread_locker code. Note: we should probably kill khelper_wq and simply use one of the global workqueues, say, system_unbound_wq, this special wq for umh buys nothing nowadays. Signed-off-by:
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Oleg Nesterov authored
After "kernel/kmod: fix use-after-free of the sub_infostructure" CLONE_VFORK in __call_usermodehelper() buys nothing, we rely on on umh_complete() in ____call_usermodehelper() anyway. Remove it. This also eliminates the unnecessary sleep/wakeup in the likely case, and this allows the next change. While at it, kill the "int wait" locals in ____call_usermodehelper() and __call_usermodehelper(), they can safely use sub_info->wait. Signed-off-by:
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Rasmus Villemoes authored
Relying on the sign (after casting to int) of the difference of two quantities for comparison is usually wrong. For example, should a-b turn out to be 2^31, the return value of cmp(a,b) is -2^31; but that would also be the return value from cmp(b, a). So a compares less than b and b compares less than a. One can also easily find three values a,b,c such that a compares less than b, b compares less than c, but a does not compare less than c. Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by:
Vyacheslav Dubeyko <slava@dubeyko.com> Signed-off-by:
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Ryusuke Konishi authored
Same story as in commit 41080b5a ("nfsd race fixes: ext2") (similar ext2 fix) except that nilfs2 needs to use insert_inode_locked4() instead of insert_inode_locked() and a bug of a check for dead inodes needs to be fixed. If nilfs_iget() is called from nfsd after nilfs_new_inode() calls insert_inode_locked4(), nilfs_iget() will wait for unlock_new_inode() at the end of nilfs_mkdir()/nilfs_create()/etc to unlock the inode. If nilfs_iget() is called before nilfs_new_inode() calls insert_inode_locked4(), it will create an in-core inode and read its data from the on-disk inode. But, nilfs_iget() will find i_nlink equals zero and fail at nilfs_read_inode_common(), which will lead it to call iget_failed() and cleanly fail. However, this sanity check doesn't work as expected for reused on-disk inodes because they leave a non-zero value in i_mode field and it hinders the test of i_nlink. This patch also fixes the issue by removing the test on i_mode that nilfs2 doesn't need. Signed-off-by:
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Markus Elfring authored
The iput() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by:
Markus Elfring <elfring@users.sourceforge.net> Signed-off-by:
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Andreas Rohner authored
This patch removes filemap_write_and_wait_range() from nilfs_sync_file(), because it triggers a data segment construction by calling nilfs_writepages() with WB_SYNC_ALL. A data segment construction does not remove the inode from the i_dirty list and it does not clear the NILFS_I_DIRTY flag. Therefore nilfs_inode_dirty() still returns true, which leads to an unnecessary duplicate segment construction in nilfs_sync_file(). A call to filemap_write_and_wait_range() is not needed, because NILFS2 does not rely on the generic writeback mechanisms. Instead it implements its own mechanism to collect all dirty pages and write them into segments. It is more efficient to initiate the segment construction directly in nilfs_sync_file() without the detour over filemap_write_and_wait_range(). Additionally the lock of i_mutex is not needed, because all code blocks that are protected by i_mutex are also protected by a NILFS transaction: Function i_mutex nilfs_transaction ------------------------------------------------------ nilfs_ioctl_setflags: yes yes nilfs_fiemap: yes no nilfs_write_begin: yes yes nilfs_write_end: yes yes nilfs_lookup: yes no nilfs_create: yes yes nilfs_link: yes yes nilfs_mknod: yes yes nilfs_symlink: yes yes nilfs_mkdir: yes yes nilfs_unlink: yes yes nilfs_rmdir: yes yes nilfs_rename: yes yes nilfs_setattr: yes yes For nilfs_lookup() i_mutex is held for the parent directory, to protect it from modification. The segment construction does not modify directory inodes, so no lock is needed. nilfs_fiemap() reads the block layout on the disk, by using nilfs_bmap_lookup_contig(). This is already protected by bmap->b_sem. Signed-off-by:
Andreas Rohner <andreas.rohner@gmx.net> Signed-off-by:
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Xunlei Pang authored
rtc_timer_do_work() only judges -ETIME failure of__rtc_set_alarm(), but doesn't handle other failures like -EIO, -EBUSY, etc. If there is a failure other than -ETIME, the next rtc_timer will stay in the timerqueue. Then later rtc_timers will be enqueued directly because they have a later expires time, so the alarm irq will never be programmed. When such failures happen, this patch will retry __rtc_set_alarm(), if still can't program the alarm time, it will remove current rtc_timer from timerqueue and fetch next one, thus preventing it from affecting other rtc timers. Signed-off-by:
Xunlei Pang <pang.xunlei@linaro.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: John Stultz <john.stultz@linaro.org> Cc: Arnd Bergmann <arnd.bergmann@linaro.org> Signed-off-by:
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Xunlei Pang authored
Currently, ab8500 doesn't set uie_unsupported of rtc_device, while it doesn't support UIE, see ab8500_rtc_set_alarm(). Thus, when going through rtc_update_irq_enable()->rtc_timer_enqueue(), there's a chance it has an alarm timer1 queued before which is going to fired, so this update timer2 will be queued because it isn't the leftmost one, which means rtc_timer_enqueue() will return 0. This will result in two problems: 1) UIE EMUL will not be used. 2) When the alarm timer1 is fired, in rtc_timer_do_work() timer2 will fail to set the alarm time, so this rtc will disfunctional due to timer2 with the earliest expires in the timerqueue. So, rtc drivers must set this flag if they don't support UIE. Signed-off-by:
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Sanchayan Maity authored
The alarm interrupt handler also reads registers which are part of SNVS and need clocks enabled. However, the resume function is called after IRQ's have been enabled, hence this leads to a abort: Unhandled fault: external abort on non-linefetch (0x1008) at 0x908c604c Internal error: : 1008 [#1] ARM Modules linked in: CPU: 0 PID: 421 Comm: sh Not tainted 3.18.0-rc5-00135-g0689c67-dirty #1592 task: 8e03e800 ti: 8cad8000 task.ti: 8cad8000 PC is at snvs_rtc_irq_handler+0x14/0x74 LR is at handle_irq_event_percpu+0x3c/0x144 Fix this by using the .{suspend/resume}_noirq callbacks instead of .{suspend/resume} . Signed-off-by:Sanchayan Maity <maitysanchayan@gmail.com> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Stefan Agner <stefan@agner.ch> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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Sanchayan Maity authored
Add clock enable and disable support for the SNVS peripheral, which is required for using the RTC within the SNVS block. The clock is not strictly enforced, as this would break the i.MX devices. The clocking for the i.MX devices seems to be enabled elsewhere and enabling RTC SNVS for Vybrid results in a crash. This patch adds the clock support but also makes it optional so Vybrid platform can use the clock if defined while making sure not to break i.MX. Signed-off-by:
Stefan Agner <stefan@agner.ch> Acked-by:
Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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Johan Hovold authored
Drop the vendor-prefix from the "ti,system-power-controller" device-tree property name. It has been agreed to make "system-power-controller" a standard property and to drop the vendor-prefix that is currently used by several drivers. Note that drivers that have used "<vendor>,system-power-controller" in a released kernel will need to support both versions. Signed-off-by:
Johan Hovold <johan@kernel.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Benot Cousson <bcousson@baylibre.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Felipe Balbi <balbi@ti.com> Signed-off-by:
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Arnaud Ebalard authored
As pointed out by Mark, it is generally useful to log the error code when reporting a failure. This patch improves existing calls to dev_err() in ISL12057 driver to also report error code. Signed-off-by:
Arnaud Ebalard <arno@natisbad.org> Suggested-by:
Mark Brown <broonie@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Peter Huewe <peter.huewe@infineon.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Grant Likely <grant.likely@linaro.org> Acked-by:
Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by:
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Arnaud Ebalard authored
As suggested by Uwe, instead of clearing oscillator failure bit unconditionally at driver load, this patch adds proper handling of the flag. The driver now returns -ENODATA when reading time from the device and oscillator failure bit is set. The flag is now cleared only when the a new time value is pushed to the device. Signed-off-by:
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Arnaud Ebalard authored
The month register of ISL12057 RTC chip includes a century bit which reports overflow of year register from 99 to 0. This bit can also be written, which allows using it to extend the time interval the chip can support from 99 to 199 years. This patch adds support for century overflow bit in tm to regs and regs to tm helpers in ISL12057 driver. This was tested by putting a device 100 years in the future (using a specific kernel due to the inability of userland tools such as date or hwclock to pass year 2038), rebooting on a kernel w/ this patch applied and verifying the device was still 100 years in the future. Signed-off-by:
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Arnaud Ebalard authored
When Intersil ISL12057 support was added by commit 70e12337 ("rtc: Add support for Intersil ISL12057 I2C RTC chip"), two masks for time registers values imported from the device were either wrong or omitted, leading to additional bits from those registers to impact read values: - mask for hour register value when reading it in AM/PM mode. As AM/PM mode is not the usual mode used by the driver, this error would only have an impact on an externally configured RTC hour later read by the driver. - mask for month value. The lack of masking would provide an erroneous value if century bit is set. This patch fixes those two masks. Fixes: 70e12337 ("rtc: Add support for Intersil ISL12057 I2C RTC chip") Signed-off-by:
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Tomas Novotny authored
Signed-off-by:
Tomas Novotny <tomas@novotny.cz> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Signed-off-by:
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Tomas Novotny authored
MCP7940x is same RTC as MCP7941x. The difference is that MCP7941x chips contain additional EEPROM on a different i2c address. DS1307 driver already supports MCP7941x, so just add a new i2c device id and rename functions and defines accordingly. Signed-off-by:
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Søren Andersen authored
Add support for the watchdog functionality of the DS1374 rtc. Based on the m41t80 watchdog functionality Note: watchdog uses the same registers as alarm. [akpm@linux-foundation.org: don't forget mutex_unlock() in ds1374_wdt_open() error path] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Soeren Andersen <san@rosetechnology.dk> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Barry Song authored
Signed-off-by:
Barry Song <Baohua.Song@csr.com> Cc: hao liu <hao.liu@csr.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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hao liu authored
Add missed alarm_irq_enable() callback for CSR SiRFSoC RTCs. [akpm@linux-foundation.org: remove unneeded cast] Signed-off-by:
hao liu <hao.liu@csr.com> Signed-off-by:
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Jan Kardell authored
In case the card is woken up of the rtc alarm, the devm_rtc_device_register function detects it as a pending alarm about a month in the future. Fix this by clearing the alarm in module probe. Signed-off-by:
Jan Kardell <jan.kardell@telliq.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Vincent Donnefort <vdonnefort@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Jan Kardell authored
According to Haoyu hym8563 datasheet this saves som power. Might be importat to battery life. And maybe it works for the NXP part as well. Signed-off-by:
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Jan Kardell authored
To guarantee that a set alarm occurs in the future, the set alarm time is rounded up to the nearest minute. Also we cannot handle UIE as it requires second precision. Signed-off-by:
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