user/sven/linux.git/kernel/trace/trace.c, branch v4.9.16

fs: Better permission checking for submounts

2017-03-15T02:02:44Z

commit 93faccbbfa958a9668d3ab4e30f38dd205cee8d8 upstream. To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reviewed-by: Trond Myklebust Reviewed-by: Seth Forshee Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-10-06T18:48:41Z

Pull tracing updates from Steven Rostedt: "This release cycle is rather small. Just a few fixes to tracing. The big change is the addition of the hwlat tracer. It not only detects SMIs, but also other latency that's caused by the hardware. I have detected some latency from large boxes having bus contention" * tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Call traceoff trigger after event is recorded ftrace/scripts: Add helper script to bisect function tracing problem functions tracing: Have max_latency be defined for HWLAT_TRACER as well tracing: Add NMI tracing in hwlat detector tracing: Have hwlat trace migrate across tracing_cpumask CPUs tracing: Add documentation for hwlat_detector tracer tracing: Added hardware latency tracer ftrace: Access ret_stack->subtime only in the function profiler function_graph: Handle TRACE_BPUTS in print_graph_comment tracing/uprobe: Drop isdigit() check in create_trace_uprobe

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-10-03T19:47:28Z

Pull perf updates from Ingo Molnar: "The main kernel side changes were: - uprobes enhancements (Masami Hiramatsu) - Uncore group events enhancements (David Carrillo-Cisneros) - x86 Intel: Add support for Skylake server uncore PMUs (Kan Liang) - x86 Intel: LBR cleanups and enhancements, for better branch annotation tracking (Peter Zijlstra) - x86 Intel: Add support for PTWRITE and power event tracing (Alexander Shishkin) - ... various fixes, cleanups and smaller enhancements. Lots of tooling changes - a couple of highlights: - Support event group view with hierarchy mode in 'perf top' and 'perf report' (Namhyung Kim) e.g.: $ perf record -e '{cycles,instructions}' make $ perf report --hierarchy --stdio ... # Overhead Command / Shared Object / Symbol # ...................... .................................. ... 25.74% 27.18%sh 19.96% 24.14%libc-2.24.so 9.55% 14.64%[.] __strcmp_sse2 1.54% 0.00%[.] __tfind 1.07% 1.13%[.] _int_malloc 0.95% 0.00%[.] __strchr_sse2 0.89% 1.39%[.] __tsearch 0.76% 0.00%[.] strlen - Add branch stack / basic block info to 'perf annotate --stdio', where for each branch, we add an asm comment after the instruction with information on how often it was taken and predicted. See example with color output at: http://vger.kernel.org/~acme/perf/annotate_basic_blocks.png (Peter Zijlstra) - Add support for using symbols in address filters with Intel PT and ARM CoreSight (hardware assisted tracing facilities) (Adrian Hunter, Mathieu Poirier) - Add support for interacting with Coresight PMU ETMs/PTMs, that are IP blocks to perform hardware assisted tracing on a ARM CPU core (Mathieu Poirier) - Support generating cross arch probes, i.e. if you specify a vmlinux file for different arch than the one in the host machine, $ perf probe --definition function_name args will generate the probe definition string needed to append to the target machine /sys/kernel/debug/tracing/kprobes_events file, using scripting (Masami Hiramatsu). - Allow configuring the default 'perf report -s' sort order in ~/.perfconfig, for instance, "sym,dso" may be more fitting for kernel developers. (Arnaldo Carvalho de Melo) - ... plus lots of other changes, refactorings, features and fixes" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (149 commits) perf tests: Add dwarf unwind test for powerpc perf probe: Match linkage name with mangled name perf probe: Fix to cut off incompatible chars from group name perf probe: Skip if the function address is 0 perf probe: Ignore the error of finding inline instance perf intel-pt: Fix decoding when there are address filters perf intel-pt: Enable decoder to handle TIP.PGD with missing IP perf intel-pt: Read address filter from AUXTRACE_INFO event perf intel-pt: Record address filter in AUXTRACE_INFO event perf intel-pt: Add a helper function for processing AUXTRACE_INFO perf intel-pt: Fix missing error codes processing auxtrace_info perf intel-pt: Add support for recording the max non-turbo ratio perf intel-pt: Fix snapshot overlap detection decoder errors perf probe: Increase debug level of SDT debug messages perf record: Add support for using symbols in address filters perf symbols: Add dso__last_symbol() perf record: Fix error paths perf record: Rename label 'out_symbol_exit' perf script: Fix vanished idle symbols perf evsel: Add support for address filters ...

Merge tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-09-26T01:40:13Z

Pull tracefs fixes from Steven Rostedt: "Al Viro has been looking at the tracefs code, and has pointed out some issues. This contains one fix by me and one by Al. I'm sure that he'll come up with more but for now I tested these patches and they don't appear to have any negative impact on tracing" * tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: fix memory leaks in tracing_buffers_splice_read() tracing: Move mutex to protect against resetting of seq data

fix memory leaks in tracing_buffers_splice_read()

2016-09-25T17:30:13Z

Cc: stable@vger.kernel.org Signed-off-by: Al Viro

tracing: Move mutex to protect against resetting of seq data

2016-09-25T14:27:08Z

The iter->seq can be reset outside the protection of the mutex. So can reading of user data. Move the mutex up to the beginning of the function. Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants") Cc: stable@vger.kernel.org # 2.6.30+ Reported-by: Al Viro Signed-off-by: Steven Rostedt

tracing: Have max_latency be defined for HWLAT_TRACER as well

2016-09-12T13:59:46Z

The hwlat tracer uses tr->max_latency, and if it's the only tracer enabled that uses it, the build will fail. Add max_latency and its file when the hwlat tracer is enabled. Link: http://lkml.kernel.org/r/d6c3b7eb-ba95-1ffa-0453-464e1e24262a@infradead.org Reported-by: Randy Dunlap Tested-by: Randy Dunlap Acked-by: Randy Dunlap Signed-off-by: Steven Rostedt

tracing: Added hardware latency tracer

2016-09-02T16:47:51Z

The hardware latency tracer has been in the PREEMPT_RT patch for some time. It is used to detect possible SMIs or any other hardware interruptions that the kernel is unaware of. Note, NMIs may also be detected, but that may be good to note as well. The logic is pretty simple. It simply creates a thread that spins on a single CPU for a specified amount of time (width) within a periodic window (window). These numbers may be adjusted by their cooresponding names in /sys/kernel/tracing/hwlat_detector/ The defaults are window = 1000000 us (1 second) width = 500000 us (1/2 second) The loop consists of: t1 = trace_clock_local(); t2 = trace_clock_local(); Where trace_clock_local() is a variant of sched_clock(). The difference of t2 - t1 is recorded as the "inner" timestamp and also the timestamp t1 - prev_t2 is recorded as the "outer" timestamp. If either of these differences are greater than the time denoted in /sys/kernel/tracing/tracing_thresh then it records the event. When this tracer is started, and tracing_thresh is zero, it changes to the default threshold of 10 us. The hwlat tracer in the PREEMPT_RT patch was originally written by Jon Masters. I have modified it quite a bit and turned it into a tracer. Based-on-code-by: Jon Masters Signed-off-by: Steven Rostedt

ftrace: probe: Add README entries for k/uprobe-events

2016-08-23T18:39:57Z

Add README entries for kprobe-events and uprobe-events. This allows user to check what options can be acceptable for running kernel. E.g. perf tools can choose correct types for the kernel. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt Cc: Alexander Shishkin Cc: Hemant Kumar Cc: Naohiro Aota Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/147151069524.12957.12957179170304055028.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

tracing: Using for_each_set_bit() to simplify trace_pid_write()

2016-07-05T15:22:40Z

Using for_each_set_bit() to simplify the code. Link: http://lkml.kernel.org/r/1467645004-11169-1-git-send-email-weiyj_lk@163.com Signed-off-by: Wei Yongjun Signed-off-by: Steven Rostedt