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2016-04-19tracing: Add hist trigger 'hex' modifier for displaying numeric fieldsTom Zanussi
Allow users to have numeric fields displayed as hex values in the output by appending '.hex' to field names: # echo hist:keys=aaa,bbb.hex:vals=ccc.hex ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/67bd431edda2af5798d7694818f7e8d71b6b3463.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add hist trigger support for clearing a traceTom Zanussi
Allow users to append 'clear' to an existing trigger in order to have the hash table cleared. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont \ [ if filter] >> event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont/clear \ [ if filter] >> event/trigger Link: http://lkml.kernel.org/r/ae15dd0d9b2f7af07a37c1ff682063e2dbcdf160.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add hist trigger support for pausing and continuing a traceTom Zanussi
Allow users to append 'pause' or 'continue' to an existing trigger in order to have it paused or to have a paused trace continue. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending \ [ if filter] >> event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause or cont \ [ if filter] >> event/trigger Link: http://lkml.kernel.org/r/b672a92c14702cb924cdf6fc27ea1809bed04907.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add hist trigger support for user-defined sorting ('sort=' param)Tom Zanussi
Allow users to specify keys and/or values to sort on. With this addition, keys and values specified using the 'keys=' and 'vals=' keywords can be used to sort the hist trigger output via a new 'sort=' keyword. If multiple sort keys are specified, the output will be sorted using the second key as a secondary sort key, etc. The default sort order is ascending; if the user wants a different sort order, '.descending' can be appended to the specific sort key. Before this addition, output was always sorted by 'hitcount' in ascending order. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy \ [ if filter] > event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/b30a41db66ba486979c4f987aff5fab500ea53b3.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add hist trigger support for compound keysTom Zanussi
Allow users to specify multiple trace event fields to use in keys by allowing multiple fields in the 'keys=' keyword. With this addition, any unique combination of any of the fields named in the 'keys' keyword will result in a new entry being added to the hash table. Link: http://lkml.kernel.org/r/0cfa24e6ac3b0dcece7737d94aa1f322ae3afc4b.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add hist trigger support for multiple values ('vals=' param)Tom Zanussi
Allow users to specify trace event fields to use in aggregated sums via a new 'vals=' keyword. Before this addition, the only aggregated sum supported was the implied value 'hitcount'. With this addition, 'hitcount' is also supported as an explicit value field, as is any numeric trace event field. This expands the hist trigger syntax from this: # echo hist:keys=xxx [ if filter] > event/trigger to this: # echo hist:keys=xxx:vals=yyy [ if filter] > event/trigger Link: http://lkml.kernel.org/r/2a5d1adb5ba6c65d7bb2148e379f2fed47f29a68.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add 'hist' event trigger commandTom Zanussi
'hist' triggers allow users to continually aggregate trace events, which can then be viewed afterwards by simply reading a 'hist' file containing the aggregation in a human-readable format. The basic idea is very simple and boils down to a mechanism whereby trace events, rather than being exhaustively dumped in raw form and viewed directly, are automatically 'compressed' into meaningful tables completely defined by the user. This is done strictly via single-line command-line commands and without the aid of any kind of programming language or interpreter. A surprising number of typical use cases can be accomplished by users via this simple mechanism. In fact, a large number of the tasks that users typically do using the more complicated script-based tracing tools, at least during the initial stages of an investigation, can be accomplished by simply specifying a set of keys and values to be used in the creation of a hash table. The Linux kernel trace event subsystem happens to provide an extensive list of keys and values ready-made for such a purpose in the form of the event format files associated with each trace event. By simply consulting the format file for field names of interest and by plugging them into the hist trigger command, users can create an endless number of useful aggregations to help with investigating various properties of the system. See Documentation/trace/events.txt for examples. hist triggers are implemented on top of the existing event trigger infrastructure, and as such are consistent with the existing triggers from a user's perspective as well. The basic syntax follows the existing trigger syntax. Users start an aggregation by writing a 'hist' trigger to the event of interest's trigger file: # echo hist:keys=xxx [ if filter] > event/trigger Once a hist trigger has been set up, by default it continually aggregates every matching event into a hash table using the event key and a value field named 'hitcount'. To view the aggregation at any point in time, simply read the 'hist' file in the same directory as the 'trigger' file: # cat event/hist The detailed syntax provides additional options for user control, and is described exhaustively in Documentation/trace/events.txt and in the virtual tracing/README file in the tracing subsystem. Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Update some tracing_map constants and commentsTom Zanussi
Make it clear exactly how many keys and values are supported through better defines, and add 1 to the vals count, since normally clients want support for at least a hitcount and two other values. Also, note the error return value for tracing_map_add_key/val_field() in the comments. Link: http://lkml.kernel.org/r/6696fa02ebc716aa344c27a571a2afaa25e5b4d4.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Fix TRACING_MAP KconfigSteven Rostedt (Red Hat)
The config option for TRACING_MAP has "default n", which is not needed because the default of configs is 'n'. Also, since the TRACING_MAP has no config prompt, there's no reason to include "If in doubt, say N" in the help text. Fixed a typo in the comments of tracing_map.h. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add lock-free tracing_mapTom Zanussi
Add tracing_map, a special-purpose lock-free map for tracing. tracing_map is designed to aggregate or 'sum' one or more values associated with a specific object of type tracing_map_elt, which is associated by the map to a given key. It provides various hooks allowing per-tracer customization and is separated out into a separate file in order to allow it to be shared between multiple tracers, but isn't meant to be generally used outside of that context. The tracing_map implementation was inspired by lock-free map algorithms originated by Dr. Cliff Click: http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf Link: http://lkml.kernel.org/r/b43d68d1add33582a396f553c8ef705a33a6a748.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Add infrastructure to allow set_event_pid to follow childrenSteven Rostedt
Add the infrastructure needed to have the PIDs in set_event_pid to automatically add PIDs of the children of the tasks that have their PIDs in set_event_pid. This will also remove PIDs from set_event_pid when a task exits This is implemented by adding hooks into the fork and exit tracepoints. On fork, the PIDs are added to the list, and on exit, they are removed. Add a new option called event_fork that when set, PIDs in set_event_pid will automatically get their children PIDs added when they fork, as well as any task that exits will have its PID removed from set_event_pid. This works for instances as well. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Use pid bitmap instead of a pid array for set_event_pidSteven Rostedt
In order to add the ability to let tasks that are filtered by the events have their children also be traced on fork (and then not traced on exit), convert the array into a pid bitmask. Most of the time the number of pids is only 32768 pids or a 4k bitmask, which is the same size as the default list currently is, and that list could grow if more pids are listed. This also greatly simplifies the code. Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19tracing: Rename check_ignore_pid() to ignore_this_task()Steven Rostedt
The name "check_ignore_pid" is confusing in trying to figure out if the pid should be ignored or not. Rename it to "ignore_this_task" which is pretty straight forward, as a task (not a pid) is passed in, and should if true should be ignored. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-04-19locking/pvqspinlock: Fix division by zero in qstat_read()Davidlohr Bueso
While playing with the qstat statistics (in <debugfs>/qlockstat/) I ran into the following splat on a VM when opening pv_hash_hops: divide error: 0000 [#1] SMP ... RIP: 0010:[<ffffffff810b61fe>] [<ffffffff810b61fe>] qstat_read+0x12e/0x1e0 ... Call Trace: [<ffffffff811cad7c>] ? mem_cgroup_commit_charge+0x6c/0xd0 [<ffffffff8119750c>] ? page_add_new_anon_rmap+0x8c/0xd0 [<ffffffff8118d3b9>] ? handle_mm_fault+0x1439/0x1b40 [<ffffffff811937a9>] ? do_mmap+0x449/0x550 [<ffffffff811d3de3>] ? __vfs_read+0x23/0xd0 [<ffffffff811d4ab2>] ? rw_verify_area+0x52/0xd0 [<ffffffff811d4bb1>] ? vfs_read+0x81/0x120 [<ffffffff811d5f12>] ? SyS_read+0x42/0xa0 [<ffffffff815720f6>] ? entry_SYSCALL_64_fastpath+0x1e/0xa8 Fix this by verifying that qstat_pv_kick_unlock is in fact non-zero, similarly to what the qstat_pv_latency_wake case does, as if nothing else, this can come from resetting the statistics, thus having 0 kicks should be quite valid in this context. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: waiman.long@hpe.com Link: http://lkml.kernel.org/r/1460961103-24953-1-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-18bpf: avoid warning for wrong pointer castArnd Bergmann
Two new functions in bpf contain a cast from a 'u64' to a pointer. This works on 64-bit architectures but causes a warning on all 32-bit architectures: kernel/trace/bpf_trace.c: In function 'bpf_perf_event_output_tp': kernel/trace/bpf_trace.c:350:13: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] u64 ctx = *(long *)r1; This changes the cast to first convert the u64 argument into a uintptr_t, which is guaranteed to be the same size as a pointer. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 9940d67c93b5 ("bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs") Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-18Merge branch 'topic/livepatch' into nextMichael Ellerman
Merge the support for live patching on ppc64le using mprofile-kernel. This branch has also been merged into the livepatching tree for v4.7.
2016-04-16Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixlet from Ingo Molnar: "Fixes a build warning on certain Kconfig combinations" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/lockdep: Fix print_collision() unused warning
2016-04-15Merge branch 'topic/livepatch' of ↵Jiri Kosina
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux into for-4.7/livepatching-ppc64le Pull livepatching support for ppc64 architecture from Michael Ellerman. Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-04-14bpf: convert relevant helper args to ARG_PTR_TO_RAW_STACKDaniel Borkmann
This patch converts all helpers that can use ARG_PTR_TO_RAW_STACK as argument type. For tc programs this is bpf_skb_load_bytes(), bpf_skb_get_tunnel_key(), bpf_skb_get_tunnel_opt(). For tracing, this optimizes bpf_get_current_comm() and bpf_probe_read(). The check in bpf_skb_load_bytes() for MAX_BPF_STACK can also be removed since the verifier already makes sure we stay within bounds on stack buffers. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14bpf, verifier: add ARG_PTR_TO_RAW_STACK typeDaniel Borkmann
When passing buffers from eBPF stack space into a helper function, we have ARG_PTR_TO_STACK argument type for helpers available. The verifier makes sure that such buffers are initialized, within boundaries, etc. However, the downside with this is that we have a couple of helper functions such as bpf_skb_load_bytes() that fill out the passed buffer in the expected success case anyway, so zero initializing them prior to the helper call is unneeded/wasted instructions in the eBPF program that can be avoided. Therefore, add a new helper function argument type called ARG_PTR_TO_RAW_STACK. The idea is to skip the STACK_MISC check in check_stack_boundary() and color the related stack slots as STACK_MISC after we checked all call arguments. Helper functions using ARG_PTR_TO_RAW_STACK must make sure that every path of the helper function will fill the provided buffer area, so that we cannot leak any uninitialized stack memory. This f.e. means that error paths need to memset() the buffers, but the expected fast-path doesn't have to do this anymore. Since there's no such helper needing more than at most one ARG_PTR_TO_RAW_STACK argument, we can keep it simple and don't need to check for multiple areas. Should in future such a use-case really appear, we have check_raw_mode() that will make sure we implement support for it first. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14bpf, verifier: add bpf_call_arg_meta for passing meta dataDaniel Borkmann
Currently, when the verifier checks calls in check_call() function, we call check_func_arg() for all 5 arguments e.g. to make sure expected types are correct. In some cases, we collect meta data (here: map pointer) to perform additional checks such as checking stack boundary on key/value sizes for subsequent arguments. As we're going to extend the meta data, add a generic struct bpf_call_arg_meta that we can use for passing into check_func_arg(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14/proc/iomem: only expose physical resource addresses to privileged usersLinus Torvalds
In commit c4004b02f8e5b ("x86: remove the kernel code/data/bss resources from /proc/iomem") I was hoping to remove the phyiscal kernel address data from /proc/iomem entirely, but that had to be reverted because some system programs actually use it. This limits all the detailed resource information to properly credentialed users instead. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-14livepatch: Allow architectures to specify an alternate ftrace locationMichael Ellerman
When livepatch tries to patch a function it takes the function address and asks ftrace to install the livepatch handler at that location. ftrace will look for an mcount call site at that exact address. On powerpc the mcount location is not the first instruction of the function, and in fact it's not at a constant offset from the start of the function. To accommodate this add a hook which arch code can override to customise the behaviour. Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-14ftrace: Make ftrace_location_range() globalMichael Ellerman
In order to support live patching on powerpc we would like to call ftrace_location_range(), so make it global. Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-14bpf/verifier: reject invalid LD_ABS | BPF_DW instructionAlexei Starovoitov
verifier must check for reserved size bits in instruction opcode and reject BPF_LD | BPF_ABS | BPF_DW and BPF_LD | BPF_IND | BPF_DW instructions, otherwise interpreter will WARN_RATELIMIT on them during execution. Fixes: ddd872bc3098 ("bpf: verifier: add checks for BPF_ABS | BPF_IND instructions") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-13sched/cpuacct: Check for NULL when using task_pt_regs()Anton Blanchard
task_pt_regs() can return NULL for kernel threads, so add a check. This fixes an oops at boot on ppc64. Reported-and-Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: efault@gmx.de Cc: htejun@gmail.com Cc: linuxppc-dev@lists.ozlabs.org Cc: tj@kernel.org Cc: yangds.fnst@cn.fujitsu.com Link: http://lkml.kernel.org/r/20160406215950.04bc3f0b@kryten Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13sched/clock: Make local_clock()/cpu_clock() inlineDaniel Lezcano
The local_clock/cpu_clock functions were changed to prevent a double identical test with sched_clock_cpu() when HAVE_UNSTABLE_SCHED_CLOCK is set. That resulted in one line functions. As these functions are in all the cases one line functions and in the hot path, it is useful to specify them as static inline in order to give a strong hint to the compiler. After verification, it appears the compiler does not inline them without this hint. Change those functions to static inline. sched_clock_cpu() is called via the inlined local_clock()/cpu_clock() functions from sched.h. So any module code including sched.h will reference sched_clock_cpu(). Thus it must be exported with the EXPORT_SYMBOL_GPL macro. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1460385514-14700-2-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13sched/clock: Remove pointless test in cpu_clock/local_clockDaniel Lezcano
In case the HAVE_UNSTABLE_SCHED_CLOCK config is set, the cpu_clock() version checks if sched_clock_stable() is not set and calls sched_clock_cpu(), otherwise it calls sched_clock(). sched_clock_cpu() checks also if sched_clock_stable() is set and, if true, calls sched_clock(). sched_clock() will be called in sched_clock_cpu() if sched_clock_stable() is true. Remove the duplicate test by directly calling sched_clock_cpu() and let the static key act in this function instead. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1460385514-14700-1-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13sched/debug: Don't dump sched debug info in SysRq-WRabin Vincent
sysrq_sched_debug_show() can dump a lot of information. Don't print out all that if we're just trying to get a list of blocked tasks (SysRq-W). The information is still accessible with SysRq-T. Signed-off-by: Rabin Vincent <rabinv@axis.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459777322-30902-1-git-send-email-rabin.vincent@axis.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13locking/rwsem: Introduce basis for down_write_killable()Michal Hocko
Introduce a generic implementation necessary for down_write_killable(). This is a trivial extension of the already existing down_write() call which can be interrupted by SIGKILL. This patch doesn't provide down_write_killable() yet because arches have to provide the necessary pieces before. rwsem_down_write_failed() which is a generic slow path for the write lock is extended to take a task state and renamed to __rwsem_down_write_failed_common(). The return value is either a valid semaphore pointer or ERR_PTR(-EINTR). rwsem_down_write_failed_killable() is exported as a new way to wait for the lock and be killable. For rwsem-spinlock implementation the current __down_write() it updated in a similar way as __rwsem_down_write_failed_common() except it doesn't need new exports just visible __down_write_killable(). Architectures which are not using the generic rwsem implementation are supposed to provide their __down_write_killable() implementation and use rwsem_down_write_failed_killable() for the slow path. Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Signed-off-by: Jason Low <jason.low2@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/1460041951-22347-7-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13locking/rwsem: Get rid of __down_write_nested()Michal Hocko
This is no longer used anywhere and all callers (__down_write()) use 0 as a subclass. Ditch __down_write_nested() to make the code easier to follow. This shouldn't introduce any functional change. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Signed-off-by: Jason Low <jason.low2@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/1460041951-22347-2-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13locking/lockdep: Deinline register_lock_class(), save 2328 bytesDenys Vlasenko
This function compiles to 1328 bytes of machine code. Three callsites. Registering a new lock class is definitely not *that* time-critical to inline it. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1460141926-13069-5-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13Merge tag 'v4.6-rc3' into perf/core, to refresh the treeIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13locking/locktorture: Fix NULL pointer dereference for cleanup pathsDavidlohr Bueso
It has been found that paths that invoke cleanups through lock_torture_cleanup() can trigger NULL pointer dereferencing bugs during the statistics printing phase. This is mainly because we should not be calling into statistics before we are sure things have been set up correctly. Specifically, early checks (and the need for handling this in the cleanup call) only include parameter checks and basic statistics allocation. Once we start write/read kthreads we then consider the test as started. As such, update the function in question to check for cxt.lwsa writer stats, if not set, we either have a bogus parameter or -ENOMEM situation and therefore only need to deal with general torture calls. Reported-and-tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bobby.prani@gmail.com Cc: dhowells@redhat.com Cc: dipankar@in.ibm.com Cc: dvhart@linux.intel.com Cc: edumazet@google.com Cc: fweisbec@gmail.com Cc: jiangshanlai@gmail.com Cc: josh@joshtriplett.org Cc: mathieu.desnoyers@efficios.com Cc: oleg@redhat.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1460476038-27060-2-git-send-email-paulmck@linux.vnet.ibm.com [ Improved the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13locking/locktorture: Fix deboosting NULL pointer dereferenceDavidlohr Bueso
For the case of rtmutex torturing we will randomly call into the boost() handler, including upon module exiting when the tasks are deboosted before stopping. In such cases the task may or may not have already been boosted, and therefore the NULL being explicitly passed can occur anywhere. Currently we only assume that the task will is at a higher prio, and in consequence, dereference a NULL pointer. This patch fixes the case of a rmmod locktorture exploding while pounding on the rtmutex lock (partial trace): task: ffff88081026cf80 ti: ffff880816120000 task.ti: ffff880816120000 RSP: 0018:ffff880816123eb0 EFLAGS: 00010206 RAX: ffff88081026cf80 RBX: ffff880816bfa630 RCX: 0000000000160d1b RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000000 RBP: ffff88081026cf80 R08: 000000000000001f R09: ffff88017c20ca80 R10: 0000000000000000 R11: 000000000048c316 R12: ffffffffa05d1840 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88203f880000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000001c0a000 CR4: 00000000000406e0 Stack: ffffffffa05d141d ffff880816bfa630 ffffffffa05d1922 ffff88081e70c2c0 ffff880816bfa630 ffffffff81095fed 0000000000000000 ffffffff8107bf60 ffff880816bfa630 ffffffff00000000 ffff880800000000 ffff880816123f08 Call Trace: [<ffffffff81095fed>] kthread+0xbd/0xe0 [<ffffffff815cf40f>] ret_from_fork+0x3f/0x70 This patch ensures that if the random state pointer is not NULL and current is not boosted, then do nothing. RIP: 0010:[<ffffffffa05c6185>] [<ffffffffa05c6185>] torture_random+0x5/0x60 [torture] [<ffffffffa05d141d>] torture_rtmutex_boost+0x1d/0x90 [locktorture] [<ffffffffa05d1922>] lock_torture_writer+0xe2/0x170 [locktorture] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bobby.prani@gmail.com Cc: dhowells@redhat.com Cc: dipankar@in.ibm.com Cc: dvhart@linux.intel.com Cc: edumazet@google.com Cc: fweisbec@gmail.com Cc: jiangshanlai@gmail.com Cc: josh@joshtriplett.org Cc: mathieu.desnoyers@efficios.com Cc: oleg@redhat.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1460476038-27060-1-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-11KEYS: Move the point of trust determination to __key_link()David Howells
Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-10bpf: simplify verifier register state assignmentsAlexei Starovoitov
verifier is using the following structure to track the state of registers: struct reg_state { enum bpf_reg_type type; union { int imm; struct bpf_map *map_ptr; }; }; and later on in states_equal() does memcmp(&old->regs[i], &cur->regs[i],..) to find equivalent states. Throughout the code of verifier there are assignements to 'imm' and 'map_ptr' fields and it's not obvious that most of the assignments into 'imm' don't need to clear extra 4 bytes (like mark_reg_unknown_value() does) to make sure that memcmp doesn't go over junk left from 'map_ptr' assignment. Simplify the code by converting 'int' into 'long' Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-10don't bother with ->d_inode->i_sb - it's always equal to ->d_sbAl Viro
... and neither can ever be NULL Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-04-08cpufreq: Call cpufreq_disable_fast_switch() in sugov_exit()Rafael J. Wysocki
Due to differences in the cpufreq core's handling of runtime CPU offline and nonboot CPUs disabling during system suspend-to-RAM, fast frequency switching gets disabled after a suspend-to-RAM and resume cycle on all of the nonboot CPUs. To prevent that from happening, move the invocation of cpufreq_disable_fast_switch() from cpufreq_exit_governor() to sugov_exit(), as the schedutil governor is the only user of fast frequency switching today anyway. That simply prevents cpufreq_disable_fast_switch() from being called without invoking the ->governor callback for the CPUFREQ_GOV_POLICY_EXIT event (which happens during system suspend now). Fixes: b7898fda5bc7 (cpufreq: Support for fast frequency switching) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-04-08bpf, verifier: further improve search pruningDaniel Borkmann
The verifier needs to go through every path of the program in order to check that it terminates safely, which can be quite a lot of instructions that need to be processed f.e. in cases with more branchy programs. With search pruning from f1bca824dabb ("bpf: add search pruning optimization to verifier") the search space can already be reduced significantly when the verifier detects that a previously walked path with same register and stack contents terminated already (see verifier's states_equal()), so the search can skip walking those states. When working with larger programs of > ~2000 (out of max 4096) insns, we found that the current limit of 32k instructions is easily hit. For example, a case we ran into is that the search space cannot be pruned due to branches at the beginning of the program that make use of certain stack space slots (STACK_MISC), which are never used in the remaining program (STACK_INVALID). Therefore, the verifier needs to walk paths for the slots in STACK_INVALID state, but also all remaining paths with a stack structure, where the slots are in STACK_MISC, which can nearly double the search space needed. After various experiments, we find that a limit of 64k processed insns is a more reasonable choice when dealing with larger programs in practice. This still allows to reject extreme crafted cases that can have a much higher complexity (f.e. > ~300k) within the 4096 insns limit due to search pruning not being able to take effect. Furthermore, we found that a lot of states can be pruned after a call instruction, f.e. we were able to reduce the search state by ~35% in some cases with this heuristic, trade-off is to keep a bit more states in env->explored_states. Usually, call instructions have a number of preceding register assignments and/or stack stores, where search pruning has a better chance to suceed in states_equal() test. The current code marks the branch targets with STATE_LIST_MARK in case of conditional jumps, and the next (t + 1) instruction in case of unconditional jump so that f.e. a backjump will walk it. We also did experiments with using t + insns[t].off + 1 as a marker in the unconditionally jump case instead of t + 1 with the rationale that these two branches of execution that converge after the label might have more potential of pruning. We found that it was a bit better, but not necessarily significantly better than the current state, perhaps also due to clang not generating back jumps often. Hence, we left that as is for now. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07bpf: sanitize bpf tracepoint accessAlexei Starovoitov
during bpf program loading remember the last byte of ctx access and at the time of attaching the program to tracepoint check that the program doesn't access bytes beyond defined in tracepoint fields This also disallows access to __dynamic_array fields, but can be relaxed in the future. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint ↵Alexei Starovoitov
programs needs two wrapper functions to fetch 'struct pt_regs *' to convert tracepoint bpf context into kprobe bpf context to reuse existing helper functions Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07bpf: register BPF_PROG_TYPE_TRACEPOINT program typeAlexei Starovoitov
register tracepoint bpf program type and let it call the same set of helper functions as BPF_PROG_TYPE_KPROBE Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07perf, bpf: allow bpf programs attach to tracepointsAlexei Starovoitov
introduce BPF_PROG_TYPE_TRACEPOINT program type and allow it to be attached to the perf tracepoint handler, which will copy the arguments into the per-cpu buffer and pass it to the bpf program as its first argument. The layout of the fields can be discovered by doing 'cat /sys/kernel/debug/tracing/events/sched/sched_switch/format' prior to the compilation of the program with exception that first 8 bytes are reserved and not accessible to the program. This area is used to store the pointer to 'struct pt_regs' which some of the bpf helpers will use: +---------+ | 8 bytes | hidden 'struct pt_regs *' (inaccessible to bpf program) +---------+ | N bytes | static tracepoint fields defined in tracepoint/format (bpf readonly) +---------+ | dynamic | __dynamic_array bytes of tracepoint (inaccessible to bpf yet) +---------+ Not that all of the fields are already dumped to user space via perf ring buffer and broken application access it directly without consulting tracepoint/format. Same rule applies here: static tracepoint fields should only be accessed in a format defined in tracepoint/format. The order of fields and field sizes are not an ABI. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07perf: split perf_trace_buf_prepare into alloc and update partsAlexei Starovoitov
split allows to move expensive update of 'struct trace_entry' to later phase. Repurpose unused 1st argument of perf_tp_event() to indicate event type. While splitting use temp variable 'rctx' instead of '*rctx' to avoid unnecessary loads done by the compiler due to -fno-strict-aliasing Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07perf: optimize perf_fetch_caller_regsAlexei Starovoitov
avoid memset in perf_fetch_caller_regs, since it's the critical path of all tracepoints. It's called from perf_sw_event_sched, perf_event_task_sched_in and all of perf_trace_##call with this_cpu_ptr(&__perf_regs[..]) which are zero initialized by perpcu init logic and subsequent call to perf_arch_fetch_caller_regs initializes the same fields on all archs, so we can safely drop memset from all of the above cases and move it into perf_ftrace_function_call that calls it with stack allocated pt_regs. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07livepatch: robustify klp_register_patch() API error checkingJiri Kosina
Commit 425595a7fc20 ("livepatch: reuse module loader code to write relocations") adds a possibility of dereferncing pointers supplied by the consumer of the livepatch API before sanity (NULL) checking them (patch and patch->mod). Spotted by smatch tool. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-04-06PKCS#7: Make trust determination dependent on contents of trust keyringDavid Howells
Make the determination of the trustworthiness of a key dependent on whether a key that can verify it is present in the supplied ring of trusted keys rather than whether or not the verifying key has KEY_FLAG_TRUSTED set. verify_pkcs7_signature() will return -ENOKEY if the PKCS#7 message trust chain cannot be verified. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06KEYS: Generalise system_verify_data() to provide access to internal contentDavid Howells
Generalise system_verify_data() to provide access to internal content through a callback. This allows all the PKCS#7 stuff to be hidden inside this function and removed from the PE file parser and the PKCS#7 test key. If external content is not required, NULL should be passed as data to the function. If the callback is not required, that can be set to NULL. The function is now called verify_pkcs7_signature() to contrast with verify_pefile_signature() and the definitions of both have been moved into linux/verification.h along with the key_being_used_for enum. Signed-off-by: David Howells <dhowells@redhat.com>