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2016-01-23wrappers for ->i_mutex accessAl Viro1-8/+8
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-27Merge branch 'for-linus' of ↵Linus Torvalds1-8/+8
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fourth vfs update from Al Viro: "d_inode() annotations from David Howells (sat in for-next since before the beginning of merge window) + four assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RCU pathwalk breakage when running into a symlink overmounting something fix I_DIO_WAKEUP definition direct-io: only inc/dec inode->i_dio_count for file systems fs/9p: fix readdir() VFS: assorted d_backing_inode() annotations VFS: fs/inode.c helpers: d_inode() annotations VFS: fs/cachefiles: d_backing_inode() annotations VFS: fs library helpers: d_inode() annotations VFS: assorted weird filesystems: d_inode() annotations VFS: normal filesystems (and lustre): d_inode() annotations VFS: security/: d_inode() annotations VFS: security/: d_backing_inode() annotations VFS: net/: d_inode() annotations VFS: net/unix: d_backing_inode() annotations VFS: kernel/: d_inode() annotations VFS: audit: d_backing_inode() annotations VFS: Fix up some ->d_inode accesses in the chelsio driver VFS: Cachefiles should perform fs modifications on the top layer only VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-17oprofile: reduce mmap_sem hold for mm->exe_fileDavidlohr Bueso1-14/+16
sync_buffer() needs the mmap_sem for two distinct operations, both only occurring upon user context switch handling: 1) Dealing with the exe_file. 2) Adding the dcookie data as we need to lookup the vma that backs it. This is done via add_sample() and add_data(). This patch isolates 1), for it will no longer need the mmap_sem for serialization. However, for now, make of the more standard get_mm_exe_file(), requiring only holding the mmap_sem to read the value, and relying on reference counting to make sure that the exe file won't dissappear underneath us while doing the get dcookie. As a consequence, for 2) we move the mmap_sem locking into where we really need it, in lookup_dcookie(). The benefits are twofold: reduce mmap_sem hold times, and cleaner code. [akpm@linux-foundation.org: export get_mm_exe_file for arch/x86/oprofile/oprofile.ko] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Robert Richter <rric@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15VFS: assorted weird filesystems: d_inode() annotationsDavid Howells1-8/+8
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-26drivers/oprofile: Replace __get_cpu_var uses for address calculationChristoph Lameter2-6/+6
Replace the uses of __get_cpu_var for address calculation with this_cpu_ptr. Cc: Robert Richter <rric@kernel.org> Cc: oprofile-list@lists.sf.net Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-03-20oprofile, nmi-timer: Fix CPU hotplug callback registrationSrivatsa S. Bhat1-10/+13
Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the nmi-timer code in oprofile by using this latter form of callback registration. Cc: Robert Richter <rric@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-04oprofile: get rid of pointless forward declarations of struct super_blockAl Viro2-2/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04oprofilefs_create_...() do not need superblock argumentAl Viro4-39/+38
same story as with oprofilefs_mkdir() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04oprofilefs_mkdir() doesn't need superblock argumentAl Viro3-11/+10
it's always equal to ->d_sb of the second argument (parent dentry), due to either being literally that, or ->d_sb of parent's parent. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04don't bother with passing superblock to oprofile_create_stats_files()Al Viro3-14/+14
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04oprofile: don't bother with passing superblock to ->create_files()Al Viro2-9/+9
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04don't bother passing sb to oprofile_create_files()Al Viro3-15/+15
it's always root->d_sb Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-15drivers: delete __cpuinit usage from all remaining drivers filesPaul Gortmaker1-2/+2
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the remaining one-off uses of the __cpuinit macros from all C files in the drivers/* directory. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-03-04fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman1-0/+1
Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-23oprofilefs: add missing ->i_mutex locking in object creationAl Viro1-3/+13
Right now it's safe only during initial mount *and* functions are asking to be abused for dynamic adding of objects. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-09mm: use mm->exe_file instead of first VM_EXECUTABLE vma->vm_fileKonstantin Khlebnikov1-14/+3
Some security modules and oprofile still uses VM_EXECUTABLE for retrieving a task's executable file. After this patch they will use mm->exe_file directly. mm->exe_file is protected with mm->mmap_sem, so locking stays the same. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [arch/tile] Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> [tomoyo] Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-27oprofile: Remove 'WQ on CPUx, prefer CPUy' warningRobert Richter1-8/+3
Under certain workloads we see the following warnings: WQ on CPU0, prefer CPU1 WQ on CPU0, prefer CPU2 WQ on CPU0, prefer CPU3 It warns the user that the wq to access a per-cpu buffers runs not on the same cpu. This happens if the wq is rescheduled on a different cpu than where the buffer is located. This was probably implemented to detect performance issues. Not sure if there actually is one as the buffers are copied to a single buffer anyway which should be the actual bottleneck. We wont change WQ implementation. Since a user can do nothing the warning is pointless. Removing it. Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
2012-06-22oprofile, perf: Use per-cpu frameworkRobert Richter1-12/+11
This changes oprofile_perf.c to use the per-cpu framework. Using the per-cpu framework should avoid error like the following: arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:28:28: error: variably modified 'perf_events' at file scope Reported-by: William Cohen <wcohen@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2012-06-21oprofile: perf: use NR_CPUS instead or nr_cpumask_bits for static arrayWill Deacon1-1/+1
The OProfile perf backend uses a static array to keep track of the perf events on the system. When compiling with CONFIG_CPUMASK_OFFSTACK=y && SMP, nr_cpumask_bits is not a compile-time constant and the build will fail with: oprofile_perf.c:28: error: variably modified 'perf_events' at file scope This patch uses NR_CPUs instead of nr_cpumask_bits for the array initialisation. If this causes space problems in the future, we can always move to dynamic allocation for the events array. Cc: Matt Fleming <matt@console-pimps.org> Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> # v2.6.37+ Signed-off-by: Robert Richter <robert.richter@amd.com>
2012-04-06simple_open: automatically convert to simple_open()Stephen Boyd1-11/+3
Many users of debugfs copy the implementation of default_open() when they want to support a custom read/write function op. This leads to a proliferation of the default_open() implementation across the entire tree. Now that the common implementation has been consolidated into libfs we can replace all the users of this function with simple_open(). This replacement was done with the following semantic patch: <smpl> @ open @ identifier open_f != simple_open; identifier i, f; @@ -int open_f(struct inode *i, struct file *f) -{ ( -if (i->i_private) -f->private_data = i->i_private; | -f->private_data = i->i_private; ) -return 0; -} @ has_open depends on open @ identifier fops; identifier open.open_f; @@ struct file_operations fops = { ... -.open = open_f, +.open = simple_open, ... }; </smpl> [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21tidy up after d_make_root() conversionAl Viro1-6/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-21switch open-coded instances of d_make_root() to new helperAl Viro1-4/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06Merge branch 'perf-core-for-linus' of ↵Linus Torvalds4-34/+209
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (106 commits) perf kvm: Fix copy & paste error in description perf script: Kill script_spec__delete perf top: Fix a memory leak perf stat: Introduce get_ratio_color() helper perf session: Remove impossible condition check perf tools: Fix feature-bits rework fallout, remove unused variable perf script: Add generic perl handler to process events perf tools: Use for_each_set_bit() to iterate over feature flags perf tools: Unify handling of features when writing feature section perf report: Accept fifos as input file perf tools: Moving code in some files perf tools: Fix out-of-bound access to struct perf_session perf tools: Continue processing header on unknown features perf tools: Improve macros for struct feature_ops perf: builtin-record: Document and check that mmap_pages must be a power of two. perf: builtin-record: Provide advice if mmap'ing fails with EPERM. perf tools: Fix truncated annotation perf script: look up thread using tid instead of pid perf tools: Look up thread names for system wide profiling perf tools: Fix comm for processes with named threads ...
2011-12-20Merge branch 'for-tip' of ↵Ingo Molnar1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core
2011-12-19oprofile: Fix uninitialized memory access when writing to writing to oprofilefsRobert Richter2-5/+13
If oprofilefs_ulong_from_user() is called with count equals zero, *val remains unchanged. Depending on the implementation it might be uninitialized. Change oprofilefs_ulong_from_user()'s interface to return count on success. Thus, we are able to return early if count equals zero which avoids using *val uninitialized. Fixing all users of oprofilefs_ulong_ from_user(). This follows write syscall implementation when count is zero: "If count is zero ... [and if] no errors are detected, 0 will be returned without causing any other effect." (man 2 write) Reported-By: Mike Waychison <mikew@google.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> Cc: oprofile-list <oprofile-list@lists.sourceforge.net> Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-07oprofile: Fix oprofile_timer_exit() breakageRobert Richter1-1/+0
Removing remainings of oprofile_timer_exit() completly. Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-15Merge branch 'core' of git://amd64.org/linux/rric into perf/coreIngo Molnar4-18/+214
2011-11-15Merge branch 'urgent' of git://amd64.org/linux/rric into perf/urgentIngo Molnar2-5/+25
2011-11-04oprofile, x86: Reimplement nmi timer mode using perf eventRobert Richter3-13/+193
The legacy x86 nmi watchdog code was removed with the implementation of the perf based nmi watchdog. This broke Oprofile's nmi timer mode. To run nmi timer mode we relied on a continuous ticking nmi source which the nmi watchdog provided. The nmi tick was no longer available and current watchdog can not be used anymore since it runs with very long periods in the range of seconds. This patch reimplements the nmi timer mode using a perf counter nmi source. V2: * removing pr_info() * fix undefined reference to `__udivdi3' for 32 bit build * fix section mismatch of .cpuinit.data:nmi_timer_cpu_nb * removed nmi timer setup in arch/x86 * implemented function stubs for op_nmi_init/exit() * made code more readable in oprofile_init() V3: * fix architectural initialization in oprofile_init() * fix CONFIG_OPROFILE_NMI_TIMER dependencies Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-04oprofile: Remove exit function for timer modeRobert Richter2-21/+17
Remove exit functions by moving init/exit code to oprofile's setup/ shutdown functions. Doing so the oprofile module exit code will be easier and less error-prone. Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-04oprofile: Fix crash when unloading module (hr timer mode)Robert Richter2-5/+25
Oprofile may crash in a KVM guest while unlaoding modules. This happens if oprofile_arch_init() fails and oprofile switches to the hr timer mode as a fallback. In this case oprofile_arch_exit() is called, but it never was initialized properly which causes the crash. This patch fixes this. oprofile: using timer interrupt. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58 PGD 41da3f067 PUD 41d80e067 PMD 0 Oops: 0002 [#1] PREEMPT SMP CPU 5 Modules linked in: oprofile(-) Pid: 2382, comm: modprobe Not tainted 3.1.0-rc7-00018-g709a39d #18 Advanced Micro Device Anaheim/Anaheim RIP: 0010:[<ffffffff8123c226>] [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58 RSP: 0018:ffff88041de1de98 EFLAGS: 00010296 RAX: 0000000000000000 RBX: ffffffffa00060e0 RCX: dead000000200200 RDX: 0000000000000000 RSI: dead000000100100 RDI: ffffffff8178c620 RBP: ffff88041de1dea8 R08: 0000000000000001 R09: 0000000000000082 R10: 0000000000000000 R11: ffff88041de1dde8 R12: 0000000000000080 R13: fffffffffffffff5 R14: 0000000000000001 R15: 0000000000610210 FS: 00007f9ae5bef700(0000) GS:ffff88042fd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000008 CR3: 000000041ca44000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process modprobe (pid: 2382, threadinfo ffff88041de1c000, task ffff88042db6d040) Stack: ffff88041de1deb8 ffffffffa0006770 ffff88041de1deb8 ffffffffa000251e ffff88041de1dec8 ffffffffa00022c2 ffff88041de1ded8 ffffffffa0004993 ffff88041de1df78 ffffffff81073115 656c69666f72706f 0000000000610200 Call Trace: [<ffffffffa000251e>] op_nmi_exit+0x15/0x17 [oprofile] [<ffffffffa00022c2>] oprofile_arch_exit+0xe/0x10 [oprofile] [<ffffffffa0004993>] oprofile_exit+0x13/0x15 [oprofile] [<ffffffff81073115>] sys_delete_module+0x1c3/0x22f [<ffffffff811bf09e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8148070b>] system_call_fastpath+0x16/0x1b Code: 20 c6 78 81 e8 c5 cc 23 00 48 8b 13 48 8b 43 08 48 be 00 01 10 00 00 00 ad de 48 b9 00 02 20 00 00 00 ad de 48 c7 c7 20 c6 78 81 89 42 08 48 89 10 48 89 33 48 89 4b 08 e8 a6 c0 23 00 5a 5b RIP [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58 RSP <ffff88041de1de98> CR2: 0000000000000008 ---[ end trace 06d4e95b6aa3b437 ]--- CC: stable@kernel.org # 2.6.37+ Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-09-13locking, oprofile: Annotate oprofilefs lock as rawThomas Gleixner3-7/+7
The oprofilefs_lock can be taken in atomic context (in profiling interrupts) and therefore cannot cannot be preempted on -rt - annotate it. In mainline this change documents the low level nature of the lock - otherwise there's no functional difference. Lockdep and Sparse checking will work as usual. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-27atomic: use <linux/atomic.h>Arun Sharma1-1/+1
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-21perf: Remove the nmi parameter from the oprofile_perf backendWill Deacon1-1/+1
In commit a8b0ca17b80e ("perf: Remove the nmi parameter from the swevent and overflow interface") one site was overlooked. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110708173442.GB31972@e102144-lin.cambridge.arm.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01perf: Add context field to perf_eventAvi Kivity1-1/+1
The perf_event overflow handler does not receive any caller-derived argument, so many callers need to resort to looking up the perf_event in their local data structure. This is ugly and doesn't scale if a single callback services many perf_events. Fix by adding a context parameter to perf_event_create_kernel_counter() (and derived hardware breakpoints APIs) and storing it in the perf_event. The field can be accessed from the callback as event->overflow_handler_context. All callers are updated. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-31oprofile: Fix locking dependency in sync_start()Robert Richter1-6/+2
This fixes the A->B/B->A locking dependency, see the warning below. The function task_exit_notify() is called with (task_exit_notifier) .rwsem set and then calls sync_buffer() which locks buffer_mutex. In sync_start() the buffer_mutex was set to prevent notifier functions to be started before sync_start() is finished. But when registering the notifier, (task_exit_notifier).rwsem is locked too, but now in different order than in sync_buffer(). In theory this causes a locking dependency, what does not occur in practice since task_exit_notify() is always called after the notifier is registered which means the lock is already released. However, after checking the notifier functions it turned out the buffer_mutex in sync_start() is unnecessary. This is because sync_buffer() may be called from the notifiers even if sync_start() did not finish yet, the buffers are already allocated but empty. No need to protect this with the mutex. So we fix this theoretical locking dependency by removing buffer_mutex in sync_start(). This is similar to the implementation before commit: 750d857 oprofile: fix crash when accessing freed task structs which introduced the locking dependency. Lockdep warning: oprofiled/4447 is trying to acquire lock: (buffer_mutex){+.+...}, at: [<ffffffffa0000e55>] sync_buffer+0x31/0x3ec [oprofile] but task is already holding lock: ((task_exit_notifier).rwsem){++++..}, at: [<ffffffff81058026>] __blocking_notifier_call_chain+0x39/0x67 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((task_exit_notifier).rwsem){++++..}: [<ffffffff8106557f>] lock_acquire+0xf8/0x11e [<ffffffff81463a2b>] down_write+0x44/0x67 [<ffffffff810581c0>] blocking_notifier_chain_register+0x52/0x8b [<ffffffff8105a6ac>] profile_event_register+0x2d/0x2f [<ffffffffa00013c1>] sync_start+0x47/0xc6 [oprofile] [<ffffffffa00001bb>] oprofile_setup+0x60/0xa5 [oprofile] [<ffffffffa00014e3>] event_buffer_open+0x59/0x8c [oprofile] [<ffffffff810cd3b9>] __dentry_open+0x1eb/0x308 [<ffffffff810cd59d>] nameidata_to_filp+0x60/0x67 [<ffffffff810daad6>] do_last+0x5be/0x6b2 [<ffffffff810dbc33>] path_openat+0xc7/0x360 [<ffffffff810dbfc5>] do_filp_open+0x3d/0x8c [<ffffffff810ccfd2>] do_sys_open+0x110/0x1a9 [<ffffffff810cd09e>] sys_open+0x20/0x22 [<ffffffff8146ad4b>] system_call_fastpath+0x16/0x1b -> #0 (buffer_mutex){+.+...}: [<ffffffff81064dfb>] __lock_acquire+0x1085/0x1711 [<ffffffff8106557f>] lock_acquire+0xf8/0x11e [<ffffffff814634f0>] mutex_lock_nested+0x63/0x309 [<ffffffffa0000e55>] sync_buffer+0x31/0x3ec [oprofile] [<ffffffffa0001226>] task_exit_notify+0x16/0x1a [oprofile] [<ffffffff81467b96>] notifier_call_chain+0x37/0x63 [<ffffffff8105803d>] __blocking_notifier_call_chain+0x50/0x67 [<ffffffff81058068>] blocking_notifier_call_chain+0x14/0x16 [<ffffffff8105a718>] profile_task_exit+0x1a/0x1c [<ffffffff81039e8f>] do_exit+0x2a/0x6fc [<ffffffff8103a5e4>] do_group_exit+0x83/0xae [<ffffffff8103a626>] sys_exit_group+0x17/0x1b [<ffffffff8146ad4b>] system_call_fastpath+0x16/0x1b other info that might help us debug this: 1 lock held by oprofiled/4447: #0: ((task_exit_notifier).rwsem){++++..}, at: [<ffffffff81058026>] __blocking_notifier_call_chain+0x39/0x67 stack backtrace: Pid: 4447, comm: oprofiled Not tainted 2.6.39-00007-gcf4d8d4 #10 Call Trace: [<ffffffff81063193>] print_circular_bug+0xae/0xbc [<ffffffff81064dfb>] __lock_acquire+0x1085/0x1711 [<ffffffffa0000e55>] ? sync_buffer+0x31/0x3ec [oprofile] [<ffffffff8106557f>] lock_acquire+0xf8/0x11e [<ffffffffa0000e55>] ? sync_buffer+0x31/0x3ec [oprofile] [<ffffffff81062627>] ? mark_lock+0x42f/0x552 [<ffffffffa0000e55>] ? sync_buffer+0x31/0x3ec [oprofile] [<ffffffff814634f0>] mutex_lock_nested+0x63/0x309 [<ffffffffa0000e55>] ? sync_buffer+0x31/0x3ec [oprofile] [<ffffffffa0000e55>] sync_buffer+0x31/0x3ec [oprofile] [<ffffffff81058026>] ? __blocking_notifier_call_chain+0x39/0x67 [<ffffffff81058026>] ? __blocking_notifier_call_chain+0x39/0x67 [<ffffffffa0001226>] task_exit_notify+0x16/0x1a [oprofile] [<ffffffff81467b96>] notifier_call_chain+0x37/0x63 [<ffffffff8105803d>] __blocking_notifier_call_chain+0x50/0x67 [<ffffffff81058068>] blocking_notifier_call_chain+0x14/0x16 [<ffffffff8105a718>] profile_task_exit+0x1a/0x1c [<ffffffff81039e8f>] do_exit+0x2a/0x6fc [<ffffffff81465031>] ? retint_swapgs+0xe/0x13 [<ffffffff8103a5e4>] do_group_exit+0x83/0xae [<ffffffff8103a626>] sys_exit_group+0x17/0x1b [<ffffffff8146ad4b>] system_call_fastpath+0x16/0x1b Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Carl Love <carll@us.ibm.com> Cc: <stable@kernel.org> # .36+ Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-05-31oprofile: Free potentially owned tasks in case of errorsRobert Richter1-4/+9
After registering the task free notifier we possibly have tasks in our dying_tasks list. Free them after unregistering the notifier in case of an error. Cc: <stable@kernel.org> # .36+ Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-05-24oprofile: Use linux/mutex.hAnton Blanchard2-2/+2
The oprofile code is still including asm/mutex.h instead of linux/mutex.h. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-02-15oprofile, s390: Rework hwsampler implementationRobert Richter3-46/+3
This patch is a rework of the hwsampler oprofile implementation that has been applied recently. Now there are less non-architectural changes. The only changes are: * introduction of oprofile_add_ext_hw_sample(), and * removal of section attributes of oprofile_timer_init/_exit(). To setup hwsampler for oprofile we need to modify start()/stop() callbacks and additional hwsampler control files in oprofilefs. We do not reinitialize the timer or hwsampler mode by restarting calling init/exit() anymore, instead hwsampler_running is used to switch the mode directly in oprofile_hwsampler_start/_stop(). For locking reasons there is also hwsampler_file that reflects the value in oprofilefs. The overall diffstat of the oprofile s390 hwsampler implemenation shows the low impact to non-architectural code: arch/Kconfig | 3 + arch/s390/Kconfig | 1 + arch/s390/oprofile/Makefile | 2 +- arch/s390/oprofile/hwsampler.c | 1256 ++++++++++++++++++++++++++++++++++ arch/s390/oprofile/hwsampler.h | 113 +++ arch/s390/oprofile/hwsampler_files.c | 162 +++++ arch/s390/oprofile/init.c | 6 +- drivers/oprofile/cpu_buffer.c | 24 +- drivers/oprofile/timer_int.c | 4 +- include/linux/oprofile.h | 7 + 10 files changed, 1567 insertions(+), 11 deletions(-) Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-02-15oprofile, s390: Enhance OProfile to support System zs hardware sampling featureHeinz Graalfs3-3/+46
OProfile is enhanced to export all files for controlling System z's hardware sampling, and to invoke hwsampler exported functions to initialize and use System z's hardware sampling. The patch invokes hwsampler_setup() during oprofile init and exports following hwsampler files under oprofilefs if hwsampler's setup succeeded: A new directory for hardware sampling based files /dev/oprofile/hwsampling/ The userland daemon must explicitly write to the following files to disable (or enable) hardware based sampling /dev/oprofile/hwsampling/hwsampler to modify the actual sampling rate /dev/oprofile/hwsampling/hw_interval to modify the amount of sampling memory (measured in 4K pages) /dev/oprofile/hwsampling/hw_sdbt_blocks The following files are read only and show the possible minimum sampling rate /dev/oprofile/hwsampling/hw_min_interval the possible maximum sampling rate /dev/oprofile/hwsampling/hw_max_interval The patch splits the oprofile_timer_[init/exit] function so that it can be also called through user context (oprofilefs) to avoid kernel oops. Applied with following changes: * whitespace changes in Makefile and timer_int.c Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com> Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-02-15oprofile: Introduce new oprofile sample add function ↵Heinz Graalfs1-7/+17
(oprofile_add_ext_hw_sample) This patch introduces a new oprofile sample add function (oprofile_add_ext_hw_sample) that can also take task_struct as an argument, which is used by the hwsampler kernel module when copying hardware samples to OProfile buffers. Applied with following changes: * removed #include <linux/module.h> * whitespace changes * removed conditional compilation (CONFIG_HAVE_HWSAMPLER) * modified order of functions * fix missing function definition in header file Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com> Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-10-30Merge branches 'perf-fixes-for-linus' and 'x86-fixes-for-linus' of ↵Linus Torvalds4-4/+22
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: jump label: Add work around to i386 gcc asm goto bug x86, ftrace: Use safe noops, drop trap test jump_label: Fix unaligned traps on sparc. jump label: Make arch_jump_label_text_poke_early() optional jump label: Fix error with preempt disable holding mutex oprofile: Remove deprecated use of flush_scheduled_work() oprofile: Fix the hang while taking the cpu offline jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex jump label: Fix module __init section race * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Check irq_remapped instead of remapping_enabled in destroy_irq()
2010-10-30Merge branch 'tip/perf/jump-label-2' of ↵Ingo Molnar2-1/+11
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2010-10-29oprofile: Remove deprecated use of flush_scheduled_work()Tejun Heo3-4/+9
flush_scheduled_work() is deprecated and scheduled to be removed. sync_stop() currently cancels cpu_buffer works inside buffer_mutex and flushes the system workqueue outside. Instead, split end_cpu_work() into two parts - stopping further work enqueues and flushing works - and do the former inside buffer_mutex and latter outside. For stable kernels v2.6.35.y and v2.6.36.y. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-10-29oprofile: Fix the hang while taking the cpu offlineSantosh Shilimkar1-0/+13
The kernel build with CONFIG_OPROFILE and CPU_HOTPLUG enabled. The oprofile is initialised using system timer in absence of hardware counters supports. Oprofile isn't started from userland. In this setup while doing a CPU offline the kernel hangs in infinite for loop inside lock_hrtimer_base() function This happens because as part of oprofile_cpu_notify(, it tries to stop an hrtimer which was never started. These per-cpu hrtimers are started when the oprfile is started. echo 1 > /dev/oprofile/enable This problem also existwhen the cpu is booted with maxcpus parameter set. When bringing the remaining cpus online the timers are started even if oprofile is not yet enabled. This patch fix this issue by adding a state variable so that these hrtimer start/stop is only attempted when oprofile is started For stable kernels v2.6.35.y and v2.6.36.y. Reported-by: Jan Sebastien <s-jan@ti.com> Tested-by: sricharan <r.sricharan@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-10-29convert get_sb_single() usersAl Viro1-4/+4
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-26fs: do not assign default i_ino in new_inodeChristoph Hellwig1-0/+1
Instead of always assigning an increasing inode number in new_inode move the call to assign it into those callers that actually need it. For now callers that need it is estimated conservatively, that is the call is added to all filesystems that do not assign an i_ino by themselves. For a few more filesystems we can avoid assigning any inode number given that they aren't user visible, and for others it could be done lazily when an inode number is actually needed, but that's left for later patches. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds2-1/+10
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-15llseek: automatically add .llseek fopArnd Bergmann2-1/+10
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15oprofile: make !CONFIG_PM function stubs static inlineRobert Richter1-2/+6
Make !CONFIG_PM function stubs static inline and remove section attribute. Signed-off-by: Robert Richter <robert.richter@amd.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 00:22:33 +0300