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* Merge branch 'for-linus' of ↵Linus Torvalds2012-10-031-41/+31
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs update from Al Viro: - big one - consolidation of descriptor-related logics; almost all of that is moved to fs/file.c (BTW, I'm seriously tempted to rename the result to fd.c. As it is, we have a situation when file_table.c is about handling of struct file and file.c is about handling of descriptor tables; the reasons are historical - file_table.c used to be about a static array of struct file we used to have way back). A lot of stray ends got cleaned up and converted to saner primitives, disgusting mess in android/binder.c is still disgusting, but at least doesn't poke so much in descriptor table guts anymore. A bunch of relatively minor races got fixed in process, plus an ext4 struct file leak. - related thing - fget_light() partially unuglified; see fdget() in there (and yes, it generates the code as good as we used to have). - also related - bits of Cyrill's procfs stuff that got entangled into that work; _not_ all of it, just the initial move to fs/proc/fd.c and switch of fdinfo to seq_file. - Alex's fs/coredump.c spiltoff - the same story, had been easier to take that commit than mess with conflicts. The rest is a separate pile, this was just a mechanical code movement. - a few misc patches all over the place. Not all for this cycle, there'll be more (and quite a few currently sit in akpm's tree)." Fix up trivial conflicts in the android binder driver, and some fairly simple conflicts due to two different changes to the sock_alloc_file() interface ("take descriptor handling from sock_alloc_file() to callers" vs "net: Providing protocol type via system.sockprotoname xattr of /proc/PID/fd entries" adding a dentry name to the socket) * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits) MAX_LFS_FILESIZE should be a loff_t compat: fs: Generic compat_sys_sendfile implementation fs: push rcu_barrier() from deactivate_locked_super() to filesystems btrfs: reada_extent doesn't need kref for refcount coredump: move core dump functionality into its own file coredump: prevent double-free on an error path in core dumper usb/gadget: fix misannotations fcntl: fix misannotations ceph: don't abuse d_delete() on failure exits hypfs: ->d_parent is never NULL or negative vfs: delete surplus inode NULL check switch simple cases of fget_light to fdget new helpers: fdget()/fdput() switch o2hb_region_dev_write() to fget_light() proc_map_files_readdir(): don't bother with grabbing files make get_file() return its argument vhost_set_vring(): turn pollstart/pollstop into bool switch prctl_set_mm_exe_file() to fget_light() switch xfs_find_handle() to fget_light() switch xfs_swapext() to fget_light() ...
| * switch simple cases of fget_light to fdgetAl Viro2012-09-271-40/+30
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * events: don't use get_unused_fd_flags() when get_unused_fd() will doAl Viro2012-09-271-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-3.7-hierarchy' of ↵Linus Torvalds2012-10-021-0/+7
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup hierarchy update from Tejun Heo: "Currently, different cgroup subsystems handle nested cgroups completely differently. There's no consistency among subsystems and the behaviors often are outright broken. People at least seem to agree that the broken hierarhcy behaviors need to be weeded out if any progress is gonna be made on this front and that the fallouts from deprecating the broken behaviors should be acceptable especially given that the current behaviors don't make much sense when nested. This patch makes cgroup emit warning messages if cgroups for subsystems with broken hierarchy behavior are nested to prepare for fixing them in the future. This was put in a separate branch because more related changes were expected (didn't make it this round) and the memory cgroup wanted to pull in this and make changes on top." * 'for-3.7-hierarchy' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them
| * | cgroup: mark subsystems with broken hierarchy support and whine if cgroups ↵Tejun Heo2012-09-141-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | are nested for them Currently, cgroup hierarchy support is a mess. cpu related subsystems behave correctly - configuration, accounting and control on a parent properly cover its children. blkio and freezer completely ignore hierarchy and treat all cgroups as if they're directly under the root cgroup. Others show yet different behaviors. These differing interpretations of cgroup hierarchy make using cgroup confusing and it impossible to co-mount controllers into the same hierarchy and obtain sane behavior. Eventually, we want full hierarchy support from all subsystems and probably a unified hierarchy. Users using separate hierarchies expecting completely different behaviors depending on the mounted subsystem is deterimental to making any progress on this front. This patch adds cgroup_subsys.broken_hierarchy and sets it to %true for controllers which are lacking in hierarchy support. The goal of this patch is two-fold. * Move users away from using hierarchy on currently non-hierarchical subsystems, so that implementing proper hierarchy support on those doesn't surprise them. * Keep track of which controllers are broken how and nudge the subsystems to implement proper hierarchy support. For now, start with a single warning message. We can whine louder later on. v2: Fixed a typo spotted by Michal. Warning message updated. v3: Updated memcg part so that it doesn't generate warning in the cases where .use_hierarchy=false doesn't make the behavior different from root.use_hierarchy=true. Fixed a typo spotted by Glauber. v4: Check ->broken_hierarchy after cgroup creation is complete so that ->create() can affect the result per Michal. Dropped unnecessary memcg root handling per Michal. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Turner <pjt@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Thomas Graf <tgraf@suug.ch> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
* | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2012-10-015-167/+425
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf update from Ingo Molnar: "Lots of changes in this cycle as well, with hundreds of commits from over 30 contributors. Most of the activity was on the tooling side. Higher level changes: - New 'perf kvm' analysis tool, from Xiao Guangrong. - New 'perf trace' system-wide tracing tool - uprobes fixes + cleanups from Oleg Nesterov. - Lots of patches to make perf build on Android out of box, from Irina Tirdea - Extend ftrace function tracing utility to be more dynamic for its users. It allows for data passing to the callback functions, as well as reading regs as if a breakpoint were to trigger at function entry. The main goal of this patch series was to allow kprobes to use ftrace as an optimized probe point when a probe is placed on an ftrace nop. With lots of help from Masami Hiramatsu, and going through lots of iterations, we finally came up with a good solution. - Add cpumask for uncore pmu, use it in 'stat', from Yan, Zheng. - Various tracing updates from Steve Rostedt - Clean up and improve 'perf sched' performance by elliminating lots of needless calls to libtraceevent. - Event group parsing support, from Jiri Olsa - UI/gtk refactorings and improvements from Namhyung Kim - Add support for non-tracepoint events in perf script python, from Feng Tang - Add --symbols to 'script', similar to the one in 'report', from Feng Tang. Infrastructure enhancements and fixes: - Convert the trace builtins to use the growing evsel/evlist tracepoint infrastructure, removing several open coded constructs like switch like series of strcmp to dispatch events, etc. Basically what had already been showcased in 'perf sched'. - Add evsel constructor for tracepoints, that uses libtraceevent just to parse the /format events file, use it in a new 'perf test' to make sure the libtraceevent format parsing regressions can be more readily caught. - Some strange errors were happening in some builds, but not on the next, reported by several people, problem was some parser related files, generated during the build, didn't had proper make deps, fix from Eric Sandeen. - Introduce struct and cache information about the environment where a perf.data file was captured, from Namhyung Kim. - Fix handling of unresolved samples when --symbols is used in 'report', from Feng Tang. - Add union member access support to 'probe', from Hyeoncheol Lee. - Fixups to die() removal, from Namhyung Kim. - Render fixes for the TUI, from Namhyung Kim. - Don't enable annotation in non symbolic view, from Namhyung Kim. - Fix pipe mode in 'report', from Namhyung Kim. - Move related stats code from stat to util/, will be used by the 'stat' kvm tool, from Xiao Guangrong. - Remove die()/exit() calls from several tools. - Resolve vdso callchains, from Jiri Olsa - Don't pass const char pointers to basename, so that we can unconditionally use libgen.h and thus avoid ifdef BIONIC lines, from David Ahern - Refactor hist formatting so that it can be reused with the GTK browser, From Namhyung Kim - Fix build for another rbtree.c change, from Adrian Hunter. - Make 'perf diff' command work with evsel hists, from Jiri Olsa. - Use the only field_sep var that is set up: symbol_conf.field_sep, fix from Jiri Olsa. - .gitignore compiled python binaries, from Namhyung Kim. - Get rid of die() in more libtraceevent places, from Namhyung Kim. - Rename libtraceevent 'private' struct member to 'priv' so that it works in C++, from Steven Rostedt - Remove lots of exit()/die() calls from tools so that the main perf exit routine can take place, from David Ahern - Fix x86 build on x86-64, from David Ahern. - {int,str,rb}list fixes from Suzuki K Poulose - perf.data header fixes from Namhyung Kim - Allow user to indicate objdump path, needed in cross environments, from Maciek Borzecki - Fix hardware cache event name generation, fix from Jiri Olsa - Add round trip test for sw, hw and cache event names, catching the problem Jiri fixed, after Jiri's patch, the test passes successfully. - Clean target should do clean for lib/traceevent too, fix from David Ahern - Check the right variable for allocation failure, fix from Namhyung Kim - Set up evsel->tp_format regardless of evsel->name being set already, fix from Namhyung Kim - Oprofile fixes from Robert Richter. - Remove perf_event_attr needless version inflation, from Jiri Olsa - Introduce libtraceevent strerror like error reporting facility, from Namhyung Kim - Add pmu mappings to perf.data header and use event names from cmd line, from Robert Richter - Fix include order for bison/flex-generated C files, from Ben Hutchings - Build fixes and documentation corrections from David Ahern - Assorted cleanups from Robert Richter - Let O= makes handle relative paths, from Steven Rostedt - perf script python fixes, from Feng Tang. - Initial bash completion support, from Frederic Weisbecker - Allow building without libelf, from Namhyung Kim. - Support DWARF CFI based unwind to have callchains when %bp based unwinding is not possible, from Jiri Olsa. - Symbol resolution fixes, while fixing support PPC64 files with an .opt ELF section was the end goal, several fixes for code that handles all architectures and cleanups are included, from Cody Schafer. - Assorted fixes for Documentation and build in 32 bit, from Robert Richter - Cache the libtraceevent event_format associated to each evsel early, so that we avoid relookups, i.e. calling pevent_find_event repeatedly when processing tracepoint events. [ This is to reduce the surface contact with libtraceevents and make clear what is that the perf tools needs from that lib: so far parsing the common and per event fields. ] - Don't stop the build if the audit libraries are not installed, fix from Namhyung Kim. - Fix bfd.h/libbfd detection with recent binutils, from Markus Trippelsdorf. - Improve warning message when libunwind devel packages not present, from Jiri Olsa" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (282 commits) perf trace: Add aliases for some syscalls perf probe: Print an enum type variable in "enum variable-name" format when showing accessible variables perf tools: Check libaudit availability for perf-trace builtin perf hists: Add missing period_* fields when collapsing a hist entry perf trace: New tool perf evsel: Export the event_format constructor perf evsel: Introduce rawptr() method perf tools: Use perf_evsel__newtp in the event parser perf evsel: The tracepoint constructor should store sys:name perf evlist: Introduce set_filter() method perf evlist: Renane set_filters method to apply_filters perf test: Add test to check we correctly parse and match syscall open parms perf evsel: Handle endianity in intval method perf evsel: Know if byte swap is needed perf tools: Allow handling a NULL cpu_map as meaning "all cpus" perf evsel: Improve tracepoint constructor setup tools lib traceevent: Fix error path on pevent_parse_event perf test: Fix build failure trace: Move trace event enable from fs_initcall to core_initcall tracing: Add an option for disabling markers ...
| * | uprobes: Introduce arch_uprobe_enable/disable_step()Sebastian Andrzej Siewior2012-09-151-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As Oleg pointed out in [0] uprobe should not use the ptrace interface for enabling/disabling single stepping. [0] http://lkml.kernel.org/r/20120730141638.GA5306@redhat.com Add the new "__weak arch" helpers which simply call user_*_single_step() as a preparation. This is only needed to not break the powerpc port, we will fold this logic into arch_uprobe_pre/post_xol() hooks later. We should also change handle_singlestep(), _disable_step(&uprobe->arch) should be called before put_uprobe(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Teach find_active_uprobe() to clear MMF_HAS_UPROBESOleg Nesterov2012-09-151-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The wrong MMF_HAS_UPROBES doesn't really hurt, just it triggers the "slow" and unnecessary handle_swbp() path if the task hits the non-uprobe breakpoint. So this patch changes find_active_uprobe() to check every valid vma and clear MMF_HAS_UPROBES if no uprobes were found. This is adds the slow O(n) path, but it is only called in unlikely case when the task hits the normal breakpoint first time after uprobe_unregister(). Note the "not strictly accurate" comment in mmf_recalc_uprobes(). We can fix this, we only need to teach vma_has_uprobes() to return a bit more more info, but I am not sure this worth the trouble. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Introduce MMF_RECALC_UPROBESOleg Nesterov2012-09-151-4/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the new MMF_RECALC_UPROBES flag, it means that MMF_HAS_UPROBES can be false positive after remove_breakpoint() or uprobe_munmap(). It is also set by uprobe_dup_mmap(), this is not optimal but simple. We could add the new hook, uprobe_dup_vma(), to set MMF_HAS_UPROBES only if the new mm actually has uprobes, but I don't think this makes sense. The next patch will use this flag to clear MMF_HAS_UPROBES. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: uprobes_treelock should not disable irqsOleg Nesterov2012-09-151-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | Nobody plays with uprobes_tree/uprobes_treelock in interrupt context, no need to disable irqs. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Don't put NULL pointer in uprobe_register()Sebastian Andrzej Siewior2012-09-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_uprobe() might return a NULL pointer, put_uprobe() can't deal with this. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Remove "verify" argument from set_orig_insn()Oleg Nesterov2012-08-281-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody does set_orig_insn(verify => false), and I think nobody will. Remove this argument. IIUC set_orig_insn(verify => false) was needed to single-step without xol area. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Fold uprobe_reset_state() into uprobe_dup_mmap()Oleg Nesterov2012-08-281-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have uprobe_dup_mmap() we can fold uprobe_reset_state() into the new hook and remove it. mmput()->uprobe_clear_state() can't be called before dup_mmap(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Introduce MMF_HAS_UPROBESOleg Nesterov2012-08-281-1/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the new MMF_HAS_UPROBES flag. It is set by install_breakpoint() and it is copied by dup_mmap(), uprobe_pre_sstep_notifier() checks it to avoid the slow path if the task was never probed. Perhaps it makes sense to check it in valid_vma(is_register => false) as well. This needs the new dup_mmap()->uprobe_dup_mmap() hook. We can't use uprobe_reset_state() or put MMF_HAS_UPROBES into MMF_INIT_MASK, we need oldmm->mmap_sem to avoid the race with uprobe_register() or mmap() from another thread. Currently we never clear this bit, it can be false-positive after uprobe_unregister() or uprobe_munmap() or if dup_mmap() hits the probed VM_DONTCOPY vma. But this is fine correctness-wise and has no effect unless the task hits the non-uprobe breakpoint. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Do not use -EEXIST in install_breakpoint() pathsOleg Nesterov2012-08-281-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | -EEXIST from install_breakpoint() no longer makes sense, all callers should simply treat it as "success". Change the code to return zero and simplify register_for_each_vma(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Change uprobe_mmap() to ignore the errors but check ↵Oleg Nesterov2012-08-281-21/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fatal_signal_pending() Once install_breakpoint() fails uprobe_mmap() "ignores" all other uprobes and returns the error. It was never really needed to to stop after the first error, and in fact it was always wrong at least in -ENOTSUPP case. Change uprobe_mmap() to ignore the errors and always return 0. This is not what we want in the long term, but until we teach the callers to handle the failure it would be better to remove the pointless complications. And this doesn't look too bad, the only "reasonable" error is ENOMEM but in this case the caller should be oom-killed in the likely case or the system has more serious problems. However it makes sense to stop if fatal_signal_pending() == T. In particular this helps if the task was oom-killed. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Kill dup_mmap()->uprobe_mmap(), simplify uprobe_mmap/munmapOleg Nesterov2012-08-281-27/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. Kill dup_mmap()->uprobe_mmap(), it was only needed to calculate new_mm->uprobes_state.count removed by the previous patch. If the forking process has a pending uprobe (int3) in vma, it will be copied by copy_page_range(), note that it checks vma->anon_vma so "Don't copy ptes" is not possible after install_breakpoint() which does anon_vma_prepare(). 2. Remove is_swbp_at_addr() and "int count" in uprobe_mmap(). Again, this was needed for uprobes_state.count. As a side effect this fixes the bug pointed out by Srikar, this code lacked the necessary put_uprobe(). 3. uprobe_munmap() becomes a nop after the previous patch. Remove the meaningless code but do not remove the helper, we will need it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Kill uprobes_state->countOleg Nesterov2012-08-281-36/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobes_state->count is only needed to avoid the slow path in uprobe_pre_sstep_notifier(). It is also checked in uprobe_munmap() but ironically its only goal to decrement this counter. However, it is very broken. Just some examples: - uprobe_mmap() can race with uprobe_unregister() and wrongly increment the counter if it hits the non-uprobe "int3". Note that install_breakpoint() checks ->consumers first and returns -EEXIST if it is NULL. "atomic_sub() if error" in uprobe_mmap() looks obviously wrong too. - uprobe_munmap() can race with uprobe_register() and wrongly decrement the counter by the same reason. - Suppose an appication tries to increase the mmapped area via sys_mremap(). vma_adjust() does uprobe_munmap(whole_vma) first, this can nullify the counter temporarily and race with another thread which can hit the bp, the application will be killed by SIGTRAP. - Suppose an application mmaps 2 consecutive areas in the same file and one (or both) of these areas has uprobes. In the likely case mmap_region()->vma_merge() suceeds. Like above, this leads to uprobe_munmap/uprobe_mmap from vma_merge()->vma_adjust() but then mmap_region() does another uprobe_mmap(resulting_vma) and doubles the counter. This patch only removes this counter and fixes the compile errors, then we will try to cleanup the changed code and add something else instead. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | uprobes: Remove check for uprobe variable in handle_swbp()Sebastian Andrzej Siewior2012-08-281-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | by the time we get here (after we pass cleanup_ret) uprobe is always is set. If it is NULL we leave very early in the code. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | uprobes: Remove redundant lock_page/unlock_pageSrikar Dronamraju2012-08-281-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | Since read_opcode() reads from the referenced page and doesnt modify the page contents nor the page attributes, there is no need to lock the page. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | perf: Add attribute to filter out callchainsFrederic Weisbecker2012-08-101-14/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introducing following bits to the the perf_event_attr struct: - exclude_callchain_kernel to filter out kernel callchain from the sample dump - exclude_callchain_user to filter out user callchain from the sample dump We need to be able to disable standard user callchain dump when we use the dwarf cfi callchain mode, because frame pointer based user callchains are useless in this mode. Implementing also exclude_callchain_kernel to have complete set of options. Signed-off-by: Jiri Olsa <jolsa@redhat.com> [ Added kernel callchains filtering ] Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Arun Sharma <asharma@fb.com> Cc: Benjamin Redelings <benjamin.redelings@nescent.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/1344345647-11536-7-git-send-email-jolsa@redhat.com Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | perf: Add ability to attach user stack dump to sampleJiri Olsa2012-08-102-1/+165
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introducing PERF_SAMPLE_STACK_USER sample type bit to trigger the dump of the user level stack on sample. The size of the dump is specified by sample_stack_user value. Being able to dump parts of the user stack, starting from the stack pointer, will be useful to make a post mortem dwarf CFI based stack unwinding. Added HAVE_PERF_USER_STACK_DUMP config option to determine if the architecture provides user stack dump on perf event samples. This needs access to the user stack pointer which is not unified across architectures. Enabling this for x86 architecture. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Original-patch-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Arun Sharma <asharma@fb.com> Cc: Benjamin Redelings <benjamin.redelings@nescent.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/1344345647-11536-6-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | perf: Add perf_output_skip function to skip bytes in sampleJiri Olsa2012-08-102-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introducing perf_output_skip function to be able to skip data within the perf ring buffer. When writing data into perf ring buffer we first reserve needed place in ring buffer and then copy the actual data. There's a possibility we won't be able to fill all the reserved size with data, so we need a way to skip the remaining bytes. This is going to be useful when storing the user stack dump, where we might end up with less data than we originally requested. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Arun Sharma <asharma@fb.com> Cc: Benjamin Redelings <benjamin.redelings@nescent.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/1344345647-11536-5-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | perf: Factor __output_copy to be usable with specific copy functionFrederic Weisbecker2012-08-102-23/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding a generic way to use __output_copy function with specific copy function via DEFINE_PERF_OUTPUT_COPY macro. Using this to add new __output_copy_user function, that provides output copy from user pointers. For x86 the copy_from_user_nmi function is used and __copy_from_user_inatomic for the rest of the architectures. This new function will be used in user stack dump on sample, coming in next patches. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Arun Sharma <asharma@fb.com> Cc: Benjamin Redelings <benjamin.redelings@nescent.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/1344345647-11536-4-git-send-email-jolsa@redhat.com Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | perf: Add ability to attach user level registers dump to sampleJiri Olsa2012-08-101-0/+66
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introducing PERF_SAMPLE_REGS_USER sample type bit to trigger the dump of user level registers on sample. Registers we want to dump are specified by sample_regs_user bitmask. Only user level registers are dumped at the moment. Meaning the register values of the user space context as it was before the user entered the kernel for whatever reason (syscall, irq, exception, or a PMI happening in userspace). The layout of the sample_regs_user bitmap is described in asm/perf_regs.h for archs that support register dump. This is going to be useful to bring Dwarf CFI based stack unwinding on top of samples. Original-patch-by: Frederic Weisbecker <fweisbec@gmail.com> [ Dump registers ABI specification. ] Signed-off-by: Jiri Olsa <jolsa@redhat.com> Suggested-by: Stephane Eranian <eranian@google.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Arun Sharma <asharma@fb.com> Cc: Benjamin Redelings <benjamin.redelings@nescent.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/1344345647-11536-3-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | perf/hwpb: Invoke __perf_event_disable() if interrupts are already disabledK.Prasad2012-09-042-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While debugging a warning message on PowerPC while using hardware breakpoints, it was discovered that when perf_event_disable is invoked through hw_breakpoint_handler function with interrupts disabled, a subsequent IPI in the code path would trigger a WARN_ON_ONCE message in smp_call_function_single function. This patch calls __perf_event_disable() when interrupts are already disabled, instead of perf_event_disable(). Reported-by: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com> Signed-off-by: K.Prasad <Prasad.Krishnan@gmail.com> [naveen.n.rao@linux.vnet.ibm.com: v3: Check to make sure we target current task] Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120802081635.5811.17737.stgit@localhost.localdomain [ Fixed build error on MIPS. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | perf_event: Switch to internal refcount, fix race with close()Al Viro2012-09-041-29/+33
|/ | | | | | | | | | | | | | | | | | Don't mess with file refcounts (or keep a reference to file, for that matter) in perf_event. Use explicit refcount of its own instead. Deal with the race between the final reference to event going away and new children getting created for it by use of atomic_long_inc_not_zero() in inherit_event(); just have the latter free what it had allocated and return NULL, that works out just fine (children of siblings of something doomed are created as singletons, same as if the child of leader had been created and immediately killed). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120820135925.GG23464@ZenIV.linux.org.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* perf/trace: Add ability to set a target task for eventsAndrew Vagin2012-07-313-4/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | A few events are interesting not only for a current task. For example, sched_stat_* events are interesting for a task which wakes up. For this reason, it will be good if such events will be delivered to a target task too. Now a target task can be set by using __perf_task(). The original idea and a draft patch belongs to Peter Zijlstra. I need these events for profiling sleep times. sched_switch is used for getting callchains and sched_stat_* is used for getting time periods. These events are combined in user space, then it can be analyzed by perf tools. Inspired-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arun Sharma <asharma@fb.com> Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: __replace_page() needs munlock_vma_page()Oleg Nesterov2012-07-301-2/+6
| | | | | | | | | | | | | | | | Like do_wp_page(), __replace_page() should do munlock_vma_page() for the case when the old page still has other !VM_LOCKED mappings. Unfortunately this needs mm/internal.h. Also, move put_page() outside of ptl lock. This doesn't really matter but looks a bit better. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182249.GA20372@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Rename vma_address() and make it return "unsigned long"Oleg Nesterov2012-07-301-10/+5
| | | | | | | | | | | | | | | | 1. vma_address() returns loff_t, this looks confusing and this is unnecessary after the previous change. Make it return "ulong", all callers truncate the result anyway. 2. Its name conflicts with mm/rmap.c:vma_address(), rename it to offset_to_vaddr(), this matches vaddr_to_offset(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182247.GA20365@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Fix register_for_each_vma()->vma_address() checkOleg Nesterov2012-07-301-4/+5
| | | | | | | | | | | | | | | | | | | | | | | 1. register_for_each_vma() checks that vma_address() == vaddr, but this is not enough. We should also ensure that vaddr >= vm_start, find_vma() guarantees "vaddr < vm_end" only. 2. After the prevous changes, register_for_each_vma() is the only reason why vma_address() has to return loff_t, all other users know that we have the valid mapping at this offset and thus the overflow is not possible. Change the code to use vaddr_to_offset() instead, imho this looks more clean/understandable and now we can change vma_address(). 3. While at it, remove the unnecessary type-cast. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182244.GA20362@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Introduce vaddr_to_offset(vma, vaddr)Oleg Nesterov2012-07-301-6/+8
| | | | | | | | | | | | | | | Add the new helper, vaddr_to_offset(vma, vaddr) which returns the offset in vma->vm_file this vaddr is mapped at. Change build_probe_list() and find_active_uprobe() to use the new helper, the next patch adds another user. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182242.GA20355@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Teach build_probe_list() to consider the rangeOleg Nesterov2012-07-301-53/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently build_probe_list() builds the list of all uprobes attached to the given inode, and the caller should filter out those who don't fall into the [start,end) range, this is sub-optimal. This patch turns find_least_offset_node() into find_node_in_range() which returns the first node inside the [min,max] range, and changes build_probe_list() to use this node as a starting point for rb_prev() and rb_next() to find all other nodes the caller needs. The resulting list is no longer sorted but we do not care. This can speed up both build_probe_list() and the callers, but there is another reason to introduce find_node_in_range(). It can be used to figure out whether the given vma has uprobes or not, this will be needed soon. While at it, shift INIT_LIST_HEAD(tmp_list) into build_probe_list(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182240.GA20352@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Fix overflow in vma_address()/find_active_uprobe()Oleg Nesterov2012-07-301-2/+2
| | | | | | | | | | | | vma->vm_pgoff is "unsigned long", it should be promoted to loff_t before the multiplication to avoid the overflow. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182233.GA20339@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Suppress uprobe_munmap() from mmput()Oleg Nesterov2012-07-301-0/+3
| | | | | | | | | | | | | | | | | | | uprobe_munmap() does get_user_pages() and it is also called from the final mmput()->exit_mmap() path. This slows down exit/mmput() for no reason, and I think it is simply dangerous/wrong to try to fault-in a page into the dying mm. If nothing else, this happens after the last sync_mm_rss(), afaics handle_mm_fault() can change the task->rss_stat and make the subsequent check_mm() unhappy. Change uprobe_munmap() to check mm->mm_users != 0. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182231.GA20336@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Uprobe_mmap/munmap needs list_for_each_entry_safe()Oleg Nesterov2012-07-301-4/+4
| | | | | | | | | | | | | | | | The bug was introduced by me in 449d0d7c ("uprobes: Simplify the usage of uprobe->pending_list"). Yes, we do not care about uprobe->pending_list after return and nobody can remove the current list entry, but put_uprobe(uprobe) can actually free it and thus we need list_for_each_safe(). Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Link: http://lkml.kernel.org/r/20120729182229.GA20329@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Clean up and document write_opcode()->lock_page(old_page)Oleg Nesterov2012-07-301-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | The comment above write_opcode()->lock_page(old_page) tells about the race with do_wp_page(). I don't really understand which exactly race it means, but afaics this lock_page() was not enough to close all races with do_wp_page(). Anyway, since: 77fc4af1b59d uprobes: Change register_for_each_vma() to take mm->mmap_sem for writing this code is always called with ->mmap_sem held for writing, so we can forget about do_wp_page(). However, we can't simply remove this lock_page(), and the only (afaics) reason is __replace_page()->try_to_free_swap(). Nothing in write_opcode() needs it, move it into __replace_page() and fix the comment. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182220.GA20322@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Kill write_opcode()->lock_page(new_page)Oleg Nesterov2012-07-301-2/+0
| | | | | | | | | | | | | | | | write_opcode() does lock_page(new_page) for no reason. Nobody can see this page until __replace_page() exposes it under ptl lock, and we do nothing with this page after pte_unmap_unlock(). If nothing else, the similar code in do_wp_page() doesn't lock the new page for page_add_new_anon_rmap/set_pte_at_notify. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182218.GA20315@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: __replace_page() should not use page_address_in_vma()Oleg Nesterov2012-07-301-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | page_address_in_vma(old_page) in __replace_page() is ugly and wrong. The caller already knows the correct virtual address, this page was found by get_user_pages(vaddr). However, page_address_in_vma() can actually fail if page->mapping was cleared by __delete_from_page_cache() after get_user_pages() returns. But this means the race with page reclaim, write_opcode() should not fail, it should retry and read this page again. Probably the race with remove_mapping() is not possible due to page_freeze_refs() logic, but afaics at least shmem_writepage()->shmem_delete_from_page_cache() can clear ->mapping. We could change __replace_page() to return -EAGAIN in this case, but it would be better to simply use the caller's vaddr and rely on page_check_address(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182216.GA20311@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* uprobes: Don't recheck vma/f_mapping in write_opcode()Oleg Nesterov2012-07-301-18/+1
| | | | | | | | | | | | | | | | write_opcode() rechecks valid_vma() and ->f_mapping, this is pointless. The caller, register_for_each_vma() or uprobe_mmap(), has already done these checks under mmap_sem. To clarify, uprobe_mmap() checks valid_vma() only, but we can rely on build_probe_list(vm_file->f_mapping->host). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182212.GA20304@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* perf: Introduce perf_pmu_migrate_context()Yan, Zheng2012-06-181-0/+36
| | | | | | | | | | Originally from Peter Zijlstra. The helper migrates perf events from one cpu to another cpu. Signed-off-by: Zheng Yan <zheng.z.yan@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1339741902-8449-5-git-send-email-zheng.z.yan@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* perf: Allow the PMU driver to choose the CPU on which to install eventsYan, Zheng2012-06-181-4/+4
| | | | | | | | | | Allow the pmu->event_init callback to change event->cpu, so the PMU driver can choose the CPU on which to install events. Signed-off-by: Zheng Yan <zheng.z.yan@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1339741902-8449-4-git-send-email-zheng.z.yan@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* perf: Avoid race between cpu hotplug and installing eventYan, Zheng2012-06-181-0/+5
| | | | | | | | | | | perf_event_open() requires the cpu on which to install event is online, but the cpu can go offline after perf_event_open checks that. Add a get_online_cpus()/put_online_cpus() pair to avoid the race. Signed-off-by: Zheng Yan <zheng.z.yan@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1339741902-8449-3-git-send-email-zheng.z.yan@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'perf/urgent' into perf/coreIngo Molnar2012-06-181-3/+7
|\ | | | | | | | | | | Merge in all fixes before applying more changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Use css_tryget() to avoid propping up css refcountSalman Qazi2012-06-181-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An rmdir pushes css's ref count to zero. However, if the associated directory is open at the time, the dentry ref count is non-zero. If the fd for this directory is then passed into perf_event_open, it does a css_get(). This bounces the ref count back up from zero. This is a problem by itself. But what makes it turn into a crash is the fact that we end up doing an extra dput, since we perform a dput when css_put sees the ref count go down to zero. css_tryget() does not fall into that trap. So, we use that instead. Reproduction test-case for the bug: #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <linux/unistd.h> #include <linux/perf_event.h> #include <string.h> #include <errno.h> #include <stdio.h> #define PERF_FLAG_PID_CGROUP (1U << 2) int perf_event_open(struct perf_event_attr *hw_event_uptr, pid_t pid, int cpu, int group_fd, unsigned long flags) { return syscall(__NR_perf_event_open,hw_event_uptr, pid, cpu, group_fd, flags); } /* * Directly poke at the perf_event bug, since it's proving hard to repro * depending on where in the kernel tree. what moved? */ int main(int argc, char **argv) { int fd; struct perf_event_attr attr; memset(&attr, 0, sizeof(attr)); attr.exclude_kernel = 1; attr.size = sizeof(attr); mkdir("/dev/cgroup/perf_event/blah", 0777); fd = open("/dev/cgroup/perf_event/blah", O_RDONLY); perror("open"); rmdir("/dev/cgroup/perf_event/blah"); sleep(2); perf_event_open(&attr, fd, 0, -1, PERF_FLAG_PID_CGROUP); perror("perf_event_open"); close(fd); return 0; } Signed-off-by: Salman Qazi <sqazi@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20120614223108.1025.2503.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | uprobes: Remove the unnecessary initialization in add_utask()Oleg Nesterov2012-06-161-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Trivial cleanup. No need to nullify ->active_uprobe after kzalloc(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120615154401.GA9633@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | uprobes: __copy_insn() needs "loff_t offset"Oleg Nesterov2012-06-161-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. __copy_insn() needs "loff_t offset", not "unsigned long", to read the file. 2. use pgoff_t for "idx" and remove the unnecessary typecast. 3. fix the typo, "&=" is not what we want 4. can't resist, rename off1 to off. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154359.GA9625@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | uprobes: Don't use loff_t for the valid virtual addressOleg Nesterov2012-06-161-17/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | loff_t looks confusing when it is used for the virtual address. Change map_info and install_breakpoint/remove_breakpoint paths to use "unsigned long". The patch doesn't change vma_address(), it can't return "long" because it is used to verify the mapping. But probably this needs some cleanups too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154355.GA9622@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | uprobes: Simplify the usage of uprobe->pending_listOleg Nesterov2012-06-161-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobe->pending_list is only used to create the temporary list, it has no meaning after we drop uprobes_mmap_hash(inode). No need to initialize this node or remove it from tmp_list, and we can use list_for_each_entry(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120615154353.GA9614@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | uprobes: Move BUG_ON(UPROBE_SWBP_INSN_SIZE) from write_opcode() to ↵Oleg Nesterov2012-06-161-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | install_breakpoint() write_opcode() ensures that UPROBE_SWBP_INSN doesn't cross the page boundary. This looks a bit confusing, the check does not depend on vaddr and it is enough to do it only once right after install_breakpoint()->arch_uprobe_analyze_insn(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154350.GA9611@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>