kernel/linux.git/Documentation/trace, branch v5.15.99

tracing/histogram: Update document for KEYS_MAX size

2022-11-10T17:15:38+00:00

commit a635beeacc6d56d2b71c39e6c0103f85b53d108e upstream. After commit 4f36c2d85ced ("tracing: Increase tracing map KEYS_MAX size"), 'keys' supports up to three fields. Signed-off-by: Zheng Yejian Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20221017103806.2479139-1-zhengyejian1@huawei.com Signed-off-by: Jonathan Corbet Signed-off-by: Greg Kroah-Hartman

tracing: Add ustring operation to filtering string pointers

2022-03-08T18:12:33+00:00

[ Upstream commit f37c3bbc635994eda203a6da4ba0f9d05165a8d6 ] Since referencing user space pointers is special, if the user wants to filter on a field that is a pointer to user space, then they need to specify it. Add a ".ustring" attribute to the field name for filters to state that the field is pointing to user space such that the kernel can take the appropriate action to read that pointer. Link: https://lore.kernel.org/all/yt9d8rvmt2jq.fsf@linux.ibm.com/ Fixes: 77360f9bbc7e ("tracing: Add test for user space strings when filtering on string pointers") Tested-by: Sven Schnelle Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin

tracing: Add test for user space strings when filtering on string pointers

2022-03-08T18:12:32+00:00

[ Upstream commit 77360f9bbc7e5e2ab7a2c8b4c0244fbbfcfc6f62 ] Pingfan reported that the following causes a fault: echo "filename ~ \"cpu\"" > events/syscalls/sys_enter_openat/filter echo 1 > events/syscalls/sys_enter_at/enable The reason is that trace event filter treats the user space pointer defined by "filename" as a normal pointer to compare against the "cpu" string. The following bug happened: kvm-03-guest16 login: [72198.026181] BUG: unable to handle page fault for address: 00007fffaae8ef60 #PF: supervisor read access in kernel mode #PF: error_code(0x0001) - permissions violation PGD 80000001008b7067 P4D 80000001008b7067 PUD 2393f1067 PMD 2393ec067 PTE 8000000108f47867 Oops: 0001 [#1] PREEMPT SMP PTI CPU: 1 PID: 1 Comm: systemd Kdump: loaded Not tainted 5.14.0-32.el9.x86_64 #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:strlen+0x0/0x20 Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31 RSP: 0018:ffffb5b900013e48 EFLAGS: 00010246 RAX: 0000000000000018 RBX: ffff8fc1c49ede00 RCX: 0000000000000000 RDX: 0000000000000020 RSI: ffff8fc1c02d601c RDI: 00007fffaae8ef60 RBP: 00007fffaae8ef60 R08: 0005034f4ddb8ea4 R09: 0000000000000000 R10: ffff8fc1c02d601c R11: 0000000000000000 R12: ffff8fc1c8a6e380 R13: 0000000000000000 R14: ffff8fc1c02d6010 R15: ffff8fc1c00453c0 FS: 00007fa86123db40(0000) GS:ffff8fc2ffd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffaae8ef60 CR3: 0000000102880001 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: filter_pred_pchar+0x18/0x40 filter_match_preds+0x31/0x70 ftrace_syscall_enter+0x27a/0x2c0 syscall_trace_enter.constprop.0+0x1aa/0x1d0 do_syscall_64+0x16/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa861d88664 The above happened because the kernel tried to access user space directly and triggered a "supervisor read access in kernel mode" fault. Worse yet, the memory could not even be loaded yet, and a SEGFAULT could happen as well. This could be true for kernel space accessing as well. To be even more robust, test both kernel and user space strings. If the string fails to read, then simply have the filter fail. Note, TASK_SIZE is used to determine if the pointer is user or kernel space and the appropriate strncpy_from_kernel/user_nofault() function is used to copy the memory. For some architectures, the compare to TASK_SIZE may always pick user space or kernel space. If it gets it wrong, the only thing is that the filter will fail to match. In the future, this needs to be fixed to have the event denote which should be used. But failing a filter is much better than panicing the machine, and that can be solved later. Link: https://lore.kernel.org/all/20220107044951.22080-1-kernelfans@gmail.com/ Link: https://lkml.kernel.org/r/20220110115532.536088fd@gandalf.local.home Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Tom Zanussi Reported-by: Pingfan Liu Tested-by: Pingfan Liu Fixes: 87a342f5db69d ("tracing/filters: Support filtering for char * strings") Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin

Documentation: coresight: Fix documentation issue

2022-01-27T10:05:20+00:00

commit 66bd1333abd7fa191f13b929c9119d6cd3df27b0 upstream. Fix the description of the directories and attributes used in cs_etm as used by perf. Drop the references to the 'configurations' sub-directory which had been removed in an earlier version of the patchset. Fixes: f71cd93d5ea4 ("Documentation: coresight: Add documentation for CoreSight config") Reported-by: German Gomex Signed-off-by: Mike Leach Link: https://lore.kernel.org/r/20211117164220.14883-1-mike.leach@linaro.org Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-09-05T18:50:41+00:00

Pull tracing updates from Steven Rostedt: - simplify the Kconfig use of FTRACE and TRACE_IRQFLAGS_SUPPORT - bootconfig can now start histograms - bootconfig supports group/all enabling - histograms now can put values in linear size buckets - execnames can be passed to synthetic events - introduce "event probes" that attach to other events and can retrieve data from pointers of fields, or record fields as different types (a pointer to a string as a string instead of just a hex number) - various fixes and clean ups * tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (35 commits) tracing/doc: Fix table format in histogram code selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes selftests/ftrace: Add selftest for testing eprobe events on synthetic events selftests/ftrace: Add test case to test adding and removing of event probe selftests/ftrace: Fix requirement check of README file selftests/ftrace: Add clear_dynamic_events() to test cases tracing: Add a probe that attaches to trace events tracing/probes: Reject events which have the same name of existing one tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs tracing/probe: Change traceprobe_set_print_fmt() to take a type tracing/probes: Use struct_size() instead of defining custom macros tracing/probes: Allow for dot delimiter as well as slash for system names tracing/probe: Have traceprobe_parse_probe_arg() take a const arg tracing: Have dynamic events have a ref counter tracing: Add DYNAMIC flag for dynamic events tracing: Replace deprecated CPU-hotplug functions. MAINTAINERS: Add an entry for os noise/latency tracepoint: Fix kerneldoc comments bootconfig/tracing/ktest: Update ktest example for boot-time tracing tools/bootconfig: Use per-group/all enable option in ftrace2bconf script ...

Merge tag 'char-misc-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2021-09-01T15:35:06+00:00

Pull char / misc driver updates from Greg KH: "Here is the big set of char/misc driver changes for 5.15-rc1. Lots of different driver subsystems are being updated in here, notably: - mhi subsystem update - fpga subsystem update - coresight/hwtracing subsystem update - interconnect subsystem update - nvmem subsystem update - parport drivers update - phy subsystem update - soundwire subsystem update and there are some other char/misc drivers being updated as well: - binder driver additions - new misc drivers - lkdtm driver updates - mei driver updates - sram driver updates - other minor driver updates. Note, there are no habanalabs driver updates in this pull request, that will probably come later before -rc1 is out in a different request. All of these have been in linux-next for a while with no reported problems" * tag 'char-misc-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (169 commits) Revert "bus: mhi: Add inbound buffers allocation flag" misc/pvpanic: fix set driver data VMCI: fix NULL pointer dereference when unmapping queue pair char: mware: fix returnvar.cocci warnings parport: remove non-zero check on count soundwire: cadence: do not extend reset delay soundwire: intel: conditionally exit clock stop mode on system suspend soundwire: intel: skip suspend/resume/wake when link was not started soundwire: intel: fix potential race condition during power down phy: qcom-qmp: Add support for SM6115 UFS phy dt-bindings: phy: qcom,qmp: Add SM6115 UFS PHY bindings phy: qmp: Provide unique clock names for DP clocks lkdtm: remove IDE_CORE_CP crashpoint lkdtm: replace SCSI_DISPATCH_CMD with SCSI_QUEUE_RQ coresight: Replace deprecated CPU-hotplug functions. Documentation: coresight: Add documentation for CoreSight config coresight: syscfg: Add initial configfs support coresight: config: Add preloaded configurations coresight: etm4x: Add complex configuration handlers to etmv4 coresight: etm-perf: Update to activate selected configuration ...

Documentation: Replace deprecated CPU-hotplug functions.

2021-08-27T23:46:17+00:00

The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Update the documentation accordingly. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210803141621.780504-2-bigeasy@linutronix.de

tracing/doc: Fix table format in histogram code

2021-08-24T13:48:34+00:00

The addition of the buckets conversion for the histogram code, updated the documentation table of available conversions, but did not update the format to accommodate the extra size needed to cover the description. Link: https://lkml.kernel.org/r/20210823100007.71ce2ba9@oasis.local.home Reported-by: Stephen Rothwell Tested-by: Stephen Rothwell Signed-off-by: Steven Rostedt (VMware)

Documentation: coresight: Add documentation for CoreSight config

2021-08-18T20:33:28+00:00

Adds documentation for the CoreSight System configuration manager. Link: https://lore.kernel.org/r/20210723165444.1048-11-mike.leach@linaro.org [Fixed coresight-config.rst documentation link] Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Signed-off-by: Mike Leach Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20210818194022.379573-11-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman

Documentation: tracing: Add histogram syntax to boot-time tracing

2021-08-16T15:37:21+00:00

Add the documentation about histogram syntax in boot-time tracing. This will allow user to write the histogram setting in a structured parameters. Link: https://lkml.kernel.org/r/162856127129.203126.15551542847575916525.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)