Commit Graph

4640 Commits

Author SHA1 Message Date
Linus Torvalds
fefa636d81 Updates for tracing and bootconfig:
- Add support for "bool" type in synthetic events
 
 - Add per instance tracing for bootconfig
 
 - Support perf-style return probe ("SYMBOL%return") in kprobes and uprobes
 
 - Allow for kprobes to be enabled earlier in boot up
 
 - Added tracepoint helper function to allow testing if tracepoints are
   enabled in headers
 
 - Synthetic events can now have dynamic strings (variable length)
 
 - Various fixes and cleanups
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Merge tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Updates for tracing and bootconfig:

   - Add support for "bool" type in synthetic events

   - Add per instance tracing for bootconfig

   - Support perf-style return probe ("SYMBOL%return") in kprobes and
     uprobes

   - Allow for kprobes to be enabled earlier in boot up

   - Added tracepoint helper function to allow testing if tracepoints
     are enabled in headers

   - Synthetic events can now have dynamic strings (variable length)

   - Various fixes and cleanups"

* tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (58 commits)
  tracing: support "bool" type in synthetic trace events
  selftests/ftrace: Add test case for synthetic event syntax errors
  tracing: Handle synthetic event array field type checking correctly
  selftests/ftrace: Change synthetic event name for inter-event-combined test
  tracing: Add synthetic event error logging
  tracing: Check that the synthetic event and field names are legal
  tracing: Move is_good_name() from trace_probe.h to trace.h
  tracing: Don't show dynamic string internals in synthetic event description
  tracing: Fix some typos in comments
  tracing/boot: Add ftrace.instance.*.alloc_snapshot option
  tracing: Fix race in trace_open and buffer resize call
  tracing: Check return value of __create_val_fields() before using its result
  tracing: Fix synthetic print fmt check for use of __get_str()
  tracing: Remove a pointless assignment
  ftrace: ftrace_global_list is renamed to ftrace_ops_list
  ftrace: Format variable declarations of ftrace_allocate_records
  ftrace: Simplify the calculation of page number for ftrace_page->records
  ftrace: Simplify the dyn_ftrace->flags macro
  ftrace: Simplify the hash calculation
  ftrace: Use fls() to get the bits for dup_hash()
  ...
2020-10-15 15:51:28 -07:00
Linus Torvalds
726eb70e0d Char/Misc driver patches for 5.10-rc1
Here is the big set of char, misc, and other assorted driver subsystem
 patches for 5.10-rc1.
 
 There's a lot of different things in here, all over the drivers/
 directory.  Some summaries:
 	- soundwire driver updates
 	- habanalabs driver updates
 	- extcon driver updates
 	- nitro_enclaves new driver
 	- fsl-mc driver and core updates
 	- mhi core and bus updates
 	- nvmem driver updates
 	- eeprom driver updates
 	- binder driver updates and fixes
 	- vbox minor bugfixes
 	- fsi driver updates
 	- w1 driver updates
 	- coresight driver updates
 	- interconnect driver updates
 	- misc driver updates
 	- other minor driver updates
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char, misc, and other assorted driver subsystem
  patches for 5.10-rc1.

  There's a lot of different things in here, all over the drivers/
  directory. Some summaries:

   - soundwire driver updates

   - habanalabs driver updates

   - extcon driver updates

   - nitro_enclaves new driver

   - fsl-mc driver and core updates

   - mhi core and bus updates

   - nvmem driver updates

   - eeprom driver updates

   - binder driver updates and fixes

   - vbox minor bugfixes

   - fsi driver updates

   - w1 driver updates

   - coresight driver updates

   - interconnect driver updates

   - misc driver updates

   - other minor driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (396 commits)
  binder: fix UAF when releasing todo list
  docs: w1: w1_therm: Fix broken xref, mistakes, clarify text
  misc: Kconfig: fix a HISI_HIKEY_USB dependency
  LSM: Fix type of id parameter in kernel_post_load_data prototype
  misc: Kconfig: add a new dependency for HISI_HIKEY_USB
  firmware_loader: fix a kernel-doc markup
  w1: w1_therm: make w1_poll_completion static
  binder: simplify the return expression of binder_mmap
  test_firmware: Test partial read support
  firmware: Add request_partial_firmware_into_buf()
  firmware: Store opt_flags in fw_priv
  fs/kernel_file_read: Add "offset" arg for partial reads
  IMA: Add support for file reads without contents
  LSM: Add "contents" flag to kernel_read_file hook
  module: Call security_kernel_post_load_data()
  firmware_loader: Use security_post_load_data()
  LSM: Introduce kernel_post_load_data() hook
  fs/kernel_read_file: Add file_size output argument
  fs/kernel_read_file: Switch buffer size arg to size_t
  fs/kernel_read_file: Remove redundant size argument
  ...
2020-10-15 10:01:51 -07:00
Axel Rasmussen
6107742d15 tracing: support "bool" type in synthetic trace events
It's common [1] to define tracepoint fields as "bool" when they contain
a true / false value. Currently, defining a synthetic event with a
"bool" field yields EINVAL. It's possible to work around this by using
e.g. u8 (assuming sizeof(bool) is 1, and bool is unsigned; if either of
these properties don't match, you get EINVAL [2]).

Supporting "bool" explicitly makes hooking this up easier and more
portable for userspace.

[1]: grep -r "bool" include/trace/events/
[2]: check_synth_field() in kernel/trace/trace_events_hist.c

Link: https://lkml.kernel.org/r/20201009220524.485102-2-axelrasmussen@google.com

Acked-by: Michel Lespinasse <walken@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:14 -04:00
Tom Zanussi
10819e2579 tracing: Handle synthetic event array field type checking correctly
Since synthetic event array types are derived from the field name,
there may be a semicolon at the end of the type which should be
stripped off.

If there are more characters following that, normal type string
checking will result in an invalid type.

Without this patch, you can end up with an invalid field type string
that gets displayed in both the synthetic event description and the
event format:

Before:

  # echo 'myevent char str[16]; int v' >> synthetic_events
  # cat synthetic_events
    myevent	char[16]; str; int v

  name: myevent
  ID: 1936
  format:
  	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
  	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
  	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
  	field:int common_pid;	offset:4;	size:4;	signed:1;

  	field:char str[16];;	offset:8;	size:16;	signed:1;
  	field:int v;	offset:40;	size:4;	signed:1;

  print fmt: "str=%s, v=%d", REC->str, REC->v

After:

  # echo 'myevent char str[16]; int v' >> synthetic_events
  # cat synthetic_events
    myevent	char[16] str; int v

  # cat events/synthetic/myevent/format
  name: myevent
  ID: 1936
  format:
	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
	field:int common_pid;	offset:4;	size:4;	signed:1;

	field:char str[16];	offset:8;	size:16;	signed:1;
	field:int v;	offset:40;	size:4;	signed:1;

  print fmt: "str=%s, v=%d", REC->str, REC->v

Link: https://lkml.kernel.org/r/6587663b56c2d45ab9d8c8472a2110713cdec97d.1602598160.git.zanussi@kernel.org

[ <rostedt@goodmis.org>: wrote parse_synth_field() snippet. ]
Fixes: 4b147936fa (tracing: Add support for 'synthetic' events)
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Tom Zanussi
d4d704637d tracing: Add synthetic event error logging
Add support for synthetic event error logging, which entails adding a
logging function for it, a way to save the synthetic event command,
and a set of specific synthetic event parse error strings and
handling.

Link: https://lkml.kernel.org/r/ed099c66df13b40cfc633aaeb17f66c37a923066.1602598160.git.zanussi@kernel.org

[ <rostedt@goodmis.org>: wrote save_cmdstr() seq_buf implementation. ]
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Tom Zanussi
9bbb33291f tracing: Check that the synthetic event and field names are legal
Call the is_good_name() function used by probe events to make sure
synthetic event and field names don't contain illegal characters and
cause unexpected parsing of synthetic event commands.

Link: https://lkml.kernel.org/r/c4d4bb59d3ac39bcbd70fba0cf837d6b1cedb015.1602598160.git.zanussi@kernel.org

Fixes: 4b147936fa (tracing: Add support for 'synthetic' events)
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Tom Zanussi
42d120e2dd tracing: Move is_good_name() from trace_probe.h to trace.h
is_good_name() is useful for other trace infrastructure, such as
synthetic events, so make it available via trace.h.

Link: https://lkml.kernel.org/r/cc6d6a2d7da6957fcbe1e2922e76d18d2bb459b4.1602598160.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Tom Zanussi
7d27adf575 tracing: Don't show dynamic string internals in synthetic event description
For synthetic event dynamic fields, the type contains "__data_loc",
which is basically an internal part of the type which is only meant to
be displayed in the format, not in the event description itself, which
is confusing to users since they can't use __data_loc on the
command-line to define an event field, which printing it would lead
them to believe.

So filter it out from the description, while leaving it in the type.

Link: https://lkml.kernel.org/r/b3b7baf7813298a5ede4ff02e2e837b91c05a724.1602598160.git.zanussi@kernel.org

Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Qiujun Huang
499f7bb085 tracing: Fix some typos in comments
s/wihin/within/
s/retrieven/retrieved/
s/suppport/support/
s/wil/will/
s/accidently/accidentally/
s/if the if the/if the/

Link: https://lkml.kernel.org/r/20201010140924.3809-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Masami Hiramatsu
c163409719 tracing/boot: Add ftrace.instance.*.alloc_snapshot option
Add ftrace.instance.*.alloc_snapshot option.

This option has been described in Documentation/trace/boottime-trace.rst
but not implemented yet.

ftrace.[instance.INSTANCE.]alloc_snapshot
   Allocate snapshot buffer.

The difference from kernel.alloc_snapshot is that the kernel.alloc_snapshot
will allocate the buffer only for the main instance, but this can allocate
buffer for any new instances.

Link: https://lkml.kernel.org/r/160234368948.400560.15313384470765915015.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Gaurav Kohli
bbeb97464e tracing: Fix race in trace_open and buffer resize call
Below race can come, if trace_open and resize of
cpu buffer is running parallely on different cpus
CPUX                                CPUY
				    ring_buffer_resize
				    atomic_read(&buffer->resize_disabled)
tracing_open
tracing_reset_online_cpus
ring_buffer_reset_cpu
rb_reset_cpu
				    rb_update_pages
				    remove/insert pages
resetting pointer

This race can cause data abort or some times infinte loop in
rb_remove_pages and rb_insert_pages while checking pages
for sanity.

Take buffer lock to fix this.

Link: https://lkml.kernel.org/r/1601976833-24377-1-git-send-email-gkohli@codeaurora.org

Cc: stable@vger.kernel.org
Fixes: b23d7a5f4a ("ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU")
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Steven Rostedt (VMware)
6d9bd13945 tracing: Check return value of __create_val_fields() before using its result
After having a typo for writing a histogram trigger.

Wrote:
  echo 'hist:key=pid:ts=common_timestamp.usec' > events/sched/sched_waking/trigger

Instead of:
  echo 'hist:key=pid:ts=common_timestamp.usecs' > events/sched/sched_waking/trigger

and the following crash happened:

 BUG: kernel NULL pointer dereference, address: 0000000000000008
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 4 PID: 1641 Comm: sh Not tainted 5.9.0-rc5-test+ #549
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:event_hist_trigger_func+0x70b/0x1ee0
 Code: 24 08 89 d5 49 89 cc e9 8c 00 00 00 4c 89 f2 41 b9 00 10 00 00 4c 89 e1 44 89 ee 4c 89 ff e8 dc d3 ff ff 45 89 ea 4b 8b 14 d7 <f6> 42 08 04 74 17 41 8b 8f c0 00 00 00 8d 71 01 41 89 b7 c0 00 00
 RSP: 0018:ffff959213d53db0 EFLAGS: 00010202
 RAX: ffffffffffffffea RBX: 0000000000000000 RCX: 0000000000084c04
 RDX: 0000000000000000 RSI: df7326aefebd174c RDI: 0000000000031080
 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001
 R10: 0000000000000001 R11: 0000000000000046 R12: ffff959211dcf690
 R13: 0000000000000001 R14: ffff95925a36e370 R15: ffff959251c89800
 FS:  00007fb9ea934740(0000) GS:ffff95925ab00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000008 CR3: 00000000c976c005 CR4: 00000000001706e0
 Call Trace:
  ? trigger_process_regex+0x78/0x110
  trigger_process_regex+0xc5/0x110
  event_trigger_write+0x71/0xd0
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fb9eaa29487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24

This was caused by accessing the hlist_data fields after the call to
__create_val_fields() without checking if the creation succeed.

Link: https://lkml.kernel.org/r/20201013154852.3abd8702@gandalf.local.home

Fixes: 63a1e5de30 ("tracing: Save normal string variables")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:00:59 -04:00
Linus Torvalds
3ad11d7ac8 block-5.10-2020-10-12
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Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Series of merge handling cleanups (Baolin, Christoph)

 - Series of blk-throttle fixes and cleanups (Baolin)

 - Series cleaning up BDI, seperating the block device from the
   backing_dev_info (Christoph)

 - Removal of bdget() as a generic API (Christoph)

 - Removal of blkdev_get() as a generic API (Christoph)

 - Cleanup of is-partition checks (Christoph)

 - Series reworking disk revalidation (Christoph)

 - Series cleaning up bio flags (Christoph)

 - bio crypt fixes (Eric)

 - IO stats inflight tweak (Gabriel)

 - blk-mq tags fixes (Hannes)

 - Buffer invalidation fixes (Jan)

 - Allow soft limits for zone append (Johannes)

 - Shared tag set improvements (John, Kashyap)

 - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)

 - DM no-wait support (Mike, Konstantin)

 - Request allocation improvements (Ming)

 - Allow md/dm/bcache to use IO stat helpers (Song)

 - Series improving blk-iocost (Tejun)

 - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
   Xianting, Yang, Yufen, yangerkun)

* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
  block: fix uapi blkzoned.h comments
  blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
  blk-mq: get rid of the dead flush handle code path
  block: get rid of unnecessary local variable
  block: fix comment and add lockdep assert
  blk-mq: use helper function to test hw stopped
  block: use helper function to test queue register
  block: remove redundant mq check
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  percpu_ref: don't refer to ref->data if it isn't allocated
  block: ratelimit handle_bad_sector() message
  blk-throttle: Re-use the throtl_set_slice_end()
  blk-throttle: Open code __throtl_de/enqueue_tg()
  blk-throttle: Move service tree validation out of the throtl_rb_first()
  blk-throttle: Move the list operation after list validation
  blk-throttle: Fix IO hang for a corner case
  blk-throttle: Avoid tracking latency if low limit is invalid
  blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
  blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
  block: Remove redundant 'return' statement
  ...
2020-10-13 12:12:44 -07:00
Linus Torvalds
3bff6112c8 These are the performance events changes for v5.10:
x86 Intel updates:
 
  - Add Jasper Lake support
 
  - Add support for TopDown metrics on Ice Lake
 
  - Fix Ice Lake & Tiger Lake uncore support, add Snow Ridge support
 
  - Add a PCI sub driver to support uncore PMUs where the PCI resources
    have been claimed already - extending the range of supported systems.
 
 x86 AMD updates:
 
  - Restore 'perf stat -a' behaviour to program the uncore PMU
    to count all CPU threads.
 
  - Fix setting the proper count when sampling Large Increment
    per Cycle events / 'paired' events.
 
  - Fix IBS Fetch sampling on F17h and some other IBS fine tuning,
    greatly reducing the number of interrupts when large sample
    periods are specified.
 
  - Extends Family 17h RAPL support to also work on compatible
    F19h machines.
 
 Core code updates:
 
  - Fix race in perf_mmap_close()
 
  - Add PERF_EV_CAP_SIBLING, to denote that sibling events should be
    closed if the leader is removed.
 
  - Smaller fixes and updates.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "x86 Intel updates:

   - Add Jasper Lake support

   - Add support for TopDown metrics on Ice Lake

   - Fix Ice Lake & Tiger Lake uncore support, add Snow Ridge support

   - Add a PCI sub driver to support uncore PMUs where the PCI resources
     have been claimed already - extending the range of supported
     systems.

  x86 AMD updates:

   - Restore 'perf stat -a' behaviour to program the uncore PMU to count
     all CPU threads.

   - Fix setting the proper count when sampling Large Increment per
     Cycle events / 'paired' events.

   - Fix IBS Fetch sampling on F17h and some other IBS fine tuning,
     greatly reducing the number of interrupts when large sample periods
     are specified.

   - Extends Family 17h RAPL support to also work on compatible F19h
     machines.

  Core code updates:

   - Fix race in perf_mmap_close()

   - Add PERF_EV_CAP_SIBLING, to denote that sibling events should be
     closed if the leader is removed.

   - Smaller fixes and updates"

* tag 'perf-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  perf/core: Fix race in the perf_mmap_close() function
  perf/x86: Fix n_metric for cancelled txn
  perf/x86: Fix n_pair for cancelled txn
  x86/events/amd/iommu: Fix sizeof mismatch
  perf/x86/intel: Check perf metrics feature for each CPU
  perf/x86/intel: Fix Ice Lake event constraint table
  perf/x86/intel/uncore: Fix the scale of the IMC free-running events
  perf/x86/intel/uncore: Fix for iio mapping on Skylake Server
  perf/x86/msr: Add Jasper Lake support
  perf/x86/intel: Add Jasper Lake support
  perf/x86/intel/uncore: Reduce the number of CBOX counters
  perf/x86/intel/uncore: Update Ice Lake uncore units
  perf/x86/intel/uncore: Split the Ice Lake and Tiger Lake MSR uncore support
  perf/x86/intel/uncore: Support PCIe3 unit on Snow Ridge
  perf/x86/intel/uncore: Generic support for the PCI sub driver
  perf/x86/intel/uncore: Factor out uncore_pci_pmu_unregister()
  perf/x86/intel/uncore: Factor out uncore_pci_pmu_register()
  perf/x86/intel/uncore: Factor out uncore_pci_find_dev_pmu()
  perf/x86/intel/uncore: Factor out uncore_pci_get_dev_die_info()
  perf/amd/uncore: Inform the user how many counters each uncore PMU has
  ...
2020-10-12 14:14:35 -07:00
Linus Torvalds
dd502a8107 This tree introduces static_call(), which is the idea of static_branch()
applied to indirect function calls. Remove a data load (indirection) by
 modifying the text.
 
 They give the flexibility of function pointers, but with better
 performance. (This is especially important for cases where
 retpolines would otherwise be used, as retpolines can be pretty
 slow.)
 
 API overview:
 
   DECLARE_STATIC_CALL(name, func);
   DEFINE_STATIC_CALL(name, func);
   DEFINE_STATIC_CALL_NULL(name, typename);
 
   static_call(name)(args...);
   static_call_cond(name)(args...);
   static_call_update(name, func);
 
 x86 is supported via text patching, otherwise basic indirect calls are used,
 with function pointers.
 
 There's a second variant using inline code patching, inspired by jump-labels,
 implemented on x86 as well.
 
 The new APIs are utilized in the x86 perf code, a heavy user of function pointers,
 where static calls speed up the PMU handler by 4.2% (!).
 
 The generic implementation is not really excercised on other architectures,
 outside of the trivial test_static_call_init() self-test.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-static_call-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull static call support from Ingo Molnar:
 "This introduces static_call(), which is the idea of static_branch()
  applied to indirect function calls. Remove a data load (indirection)
  by modifying the text.

  They give the flexibility of function pointers, but with better
  performance. (This is especially important for cases where retpolines
  would otherwise be used, as retpolines can be pretty slow.)

  API overview:

      DECLARE_STATIC_CALL(name, func);
      DEFINE_STATIC_CALL(name, func);
      DEFINE_STATIC_CALL_NULL(name, typename);

      static_call(name)(args...);
      static_call_cond(name)(args...);
      static_call_update(name, func);

  x86 is supported via text patching, otherwise basic indirect calls are
  used, with function pointers.

  There's a second variant using inline code patching, inspired by
  jump-labels, implemented on x86 as well.

  The new APIs are utilized in the x86 perf code, a heavy user of
  function pointers, where static calls speed up the PMU handler by
  4.2% (!).

  The generic implementation is not really excercised on other
  architectures, outside of the trivial test_static_call_init()
  self-test"

* tag 'core-static_call-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  static_call: Fix return type of static_call_init
  tracepoint: Fix out of sync data passing by static caller
  tracepoint: Fix overly long tracepoint names
  x86/perf, static_call: Optimize x86_pmu methods
  tracepoint: Optimize using static_call()
  static_call: Allow early init
  static_call: Add some validation
  static_call: Handle tail-calls
  static_call: Add static_call_cond()
  x86/alternatives: Teach text_poke_bp() to emulate RET
  static_call: Add simple self-test for static calls
  x86/static_call: Add inline static call implementation for x86-64
  x86/static_call: Add out-of-line static call implementation
  static_call: Avoid kprobes on inline static_call()s
  static_call: Add inline static call infrastructure
  static_call: Add basic static call infrastructure
  compiler.h: Make __ADDRESSABLE() symbol truly unique
  jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved()
  module: Properly propagate MODULE_STATE_COMING failure
  module: Fix up module_notifier return values
  ...
2020-10-12 13:58:15 -07:00
Steven Rostedt (VMware)
848183553e tracing: Fix synthetic print fmt check for use of __get_str()
A cut and paste error had the check to use __get_str() test "is_dynamic"
twice, instead of checking "is_string && is_dynamic".

Link: https://lore.kernel.org/r/d34dccd5-96ba-a2d9-46ea-de8807525deb@canonical.com

Reported-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:07 -04:00
Sudip Mukherjee
43aa422c0c tracing: Remove a pointless assignment
The variable 'len' has been assigned a value but is not used after that.
So, remove the assignement.

Link: https://lkml.kernel.org/r/20200930184303.22896-1-sudipm.mukherjee@gmail.com

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Steven Rostedt (VMware)
7ba031e8b7 ftrace: Format variable declarations of ftrace_allocate_records
I hate when unrelated variables are declared on the same line.
Split them.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Wei Yang
b40c6eabfc ftrace: Simplify the calculation of page number for ftrace_page->records
Based on the following two reasones, we could simplify the calculation:

  - If the number after roundup count is not power of 2, we would
    definitely have more than 1 empty page with a higher order.
  - get_count_order() just return current order, so one lower order
    could meet the requirement.

The calculation could be simplified by lower one order level when pages
are not power of 2.

Link: https://lkml.kernel.org/r/20200831031104.23322-5-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Steven Rostedt (VMware)
be49313273 ftrace: Simplify the hash calculation
No need to add a check to subtract the number of bits if bits is zero after
fls(). Just divide the size by two before calling it. This does give the
same answer for size of 0 and 1, but that's fine.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Wei Yang
59e65b3358 ftrace: Use fls() to get the bits for dup_hash()
The effect here is to get the number of bits, lets use fls() to do
this job.

Link: https://lkml.kernel.org/r/20200831031104.23322-3-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Steven Rostedt (VMware)
8db4d6bfbb tracing: Change synthetic event string format to limit printed length
Change the format for printing synthetic field strings to limit the
length of the string printed even if it's not correctly terminated.

Link: https://lore.kernel.org/r/20201002210036.0200371b@oasis.local.home
Link: https://lkml.kernel.org/r/b6bdb34e70d970e8026daa3503db6b8e5cdad524.1601848695.git.zanussi@kernel.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Tom Zanussi
1bc36bd4a8 tracing: Add README information for synthetic_events file
Add an entry with a basic description of events/synthetic_events along
with a simple example.

Link: https://lkml.kernel.org/r/3c7f178cf95aaeebc01eda7d95600dd937233eb7.1601848695.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:28:14 -04:00
Tom Zanussi
bd82631d7c tracing: Add support for dynamic strings to synthetic events
Currently, sythetic events only support static string fields such as:

  # echo 'test_latency u64 lat; char somename[32]' > /sys/kernel/debug/tracing/synthetic_events

Which is fine, but wastes a lot of space in the event.

It also prevents the most commonly-defined strings in the existing
trace events e.g. those defined using __string(), from being passed to
synthetic events via the trace() action.

With this change, synthetic events with dynamic fields can be defined:

  # echo 'test_latency u64 lat; char somename[]' > /sys/kernel/debug/tracing/synthetic_events

And the trace() action can be used to generate events using either
dynamic or static strings:

  # echo 'hist:keys=name:lat=common_timestamp.usecs-$ts0:onmatch(sys.event).test_latency($lat,name)' > /sys/kernel/debug/tracing/events

The synthetic event dynamic strings are implemented in the same way as
the existing __data_loc strings and appear as such in the format file.

[ <rostedt@goodmis.org>: added __set_synth_event_print_fmt() changes:

  I added the following to make it work with trace-cmd. Dynamic strings
  must have __get_str() for events in the print_fmt otherwise it can't be
  parsed correctly. ]

Link: https://lore.kernel.org/r/cover.1601588066.git.zanussi@kernel.org
Link: https://lkml.kernel.org/r/3ed35b6d0e390f5b94cb4a9ba1cc18f5982ab277.1601848695.git.zanussi@kernel.org

Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 19:32:18 -04:00
Tom Zanussi
63a1e5de30 tracing: Save normal string variables
String variables created as field variables and save variables are
already handled properly by having their values copied when set.  The
same isn't done for normal variables, but needs to be - simply saving
a pointer to a string contained in an old event isn't sufficient,
since that event's data may quickly become overwritten and therefore a
string pointer to it could yield garbage.

This change uses the same mechanism as field variables and simply
appends the new strings to the existing per-element field_var_str[]
array allocated for that purpose.

Link: https://lkml.kernel.org/r/1c1a03798b02e67307412a0c719d1bfb69b13007.1601848695.git.zanussi@kernel.org

Fixes: 02205a6752 (tracing: Add support for 'field variables')
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 18:13:53 -04:00
Tom Zanussi
8fbeb52a59 tracing: Fix parse_synth_field() error handling
synth_field_size() returns either a positive size or an error (zero or
a negative value). However, the existing code assumes the only error
value is 0. It doesn't handle negative error codes, as it assigns
directly to field->size (a size_t; unsigned), thereby interpreting the
error code as a valid size instead.

Do the test before assignment to field->size.

[ axelrasmussen@google.com: changelog addition, first paragraph above ]

Link: https://lkml.kernel.org/r/9b6946d9776b2eeb43227678158196de1c3c6e1d.1601848695.git.zanussi@kernel.org

Fixes: 4b147936fa (tracing: Add support for 'synthetic' events)
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 18:13:53 -04:00
Tom Zanussi
4a4a56b4e7 tracing: Change STR_VAR_MAX_LEN
32 is too small for this value, and anyway it makes more sense to use
MAX_FILTER_STR_VAL, as this is also the value used for variable-length
__strings.

Link: https://lkml.kernel.org/r/6adfd1668ac1fd8670bd58206944a762061a5559.1601848695.git.zanussi@kernel.org

Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 18:13:53 -04:00
Christoph Hellwig
10ed16662d block: add a bdget_part helper
All remaining callers of bdget() outside of fs/block_dev.c want to get a
reference to the struct block_device for a given struct hd_struct.  Add
a helper just for that and then mark bdget static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:38:33 -06:00
Tingwei Zhang
458999c6f6 tracing: Add trace_export support for trace_marker
Add the support to route trace_marker buffer to other destination
via trace_export.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05 12:43:53 +02:00
Tingwei Zhang
8ab7a2b705 tracing: Add trace_export support for event trace
Only function traces can be exported to other destinations currently.
This patch exports event trace as well. Move trace export related
function to the beginning of file so other trace can call
trace_process_export() to export.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05 12:43:53 +02:00
Tingwei Zhang
8438f52114 tracing: Add flag to control different traces
More traces like event trace or trace marker will be supported.
Add flag for difference traces, so that they can be controlled
separately. Move current function trace to it's own flag
instead of global ftrace enable flag.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05 12:43:53 +02:00
Qiujun Huang
fdda88d31a ftrace: Fix some typos in comment
s/coorditate/coordinate/
s/emty/empty/
s/preeptive/preemptive/
s/succes/success/
s/carefule/careful/

Link: https://lkml.kernel.org/r/20201002143126.2890-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-02 14:05:48 -04:00
Linus Torvalds
aa5ff93523 Two tracing fixes:
- Fix temp buffer accounting that caused a WARNING for
   ftrace_dump_on_opps()
 
 - Move the recursion check in one of the function callback helpers to the
   beginning of the function, as if the rcu_is_watching() gets traced, it
   will cause a recursive loop that will crash the kernel.
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Merge tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two tracing fixes:

   - Fix temp buffer accounting that caused a WARNING for
     ftrace_dump_on_opps()

   - Move the recursion check in one of the function callback helpers to
     the beginning of the function, as if the rcu_is_watching() gets
     traced, it will cause a recursive loop that will crash the kernel"

* tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Move RCU is watching check after recursion check
  tracing: Fix trace_find_next_entry() accounting of temp buffer size
2020-10-01 09:41:02 -07:00
Steven Rostedt (VMware)
b40341fad6 ftrace: Move RCU is watching check after recursion check
The first thing that the ftrace function callback helper functions should do
is to check for recursion. Peter Zijlstra found that when
"rcu_is_watching()" had its notrace removed, it caused perf function tracing
to crash. This is because the call of rcu_is_watching() is tested before
function recursion is checked and and if it is traced, it will cause an
infinite recursion loop.

rcu_is_watching() should still stay notrace, but to prevent this should
never had crashed in the first place. The recursion prevention must be the
first thing done in callback functions.

Link: https://lore.kernel.org/r/20200929112541.GM2628@hirez.programming.kicks-ass.net

Cc: stable@vger.kernel.org
Cc: Paul McKenney <paulmck@kernel.org>
Fixes: c68c0fa293 ("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-29 13:05:10 -04:00
Steven Rostedt (VMware)
851e6f61cd tracing: Fix trace_find_next_entry() accounting of temp buffer size
The temp buffer size variable for trace_find_next_entry() was incorrectly
being updated when the size did not change. The temp buffer size should only
be updated when it is reallocated.

This is mostly an issue when used with ftrace_dump(). That's because
ftrace_dump() can not allocate a new buffer, and instead uses a temporary
buffer with a fix size. But the variable that keeps track of that size is
incorrectly updated with each call, and it could fall into the path that
would try to reallocate the buffer and produce a warning.

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 1601 at kernel/trace/trace.c:3548
trace_find_next_entry+0xd0/0xe0
 Modules linked in [..]
 CPU: 1 PID: 1601 Comm: bash Not tainted 5.9.0-rc5-test+ #521
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03
07/14/2016
 RIP: 0010:trace_find_next_entry+0xd0/0xe0
 Code: 40 21 00 00 4c 89 e1 31 d2 4c 89 ee 48 89 df e8 c6 9e ff ff 89 ab 54
21 00 00 5b 5d 41 5c 41 5d c3 48 63 d5 eb bf 31 c0 eb f0 <0f> 0b 48 63 d5 eb
b4 66 0f 1f 84 00 00 00 00 00 53 48 8d 8f 60 21
 RSP: 0018:ffff95a4f2e8bd70 EFLAGS: 00010046
 RAX: ffffffff96679fc0 RBX: ffffffff97910de0 RCX: ffffffff96679fc0
 RDX: ffff95a4f2e8bd98 RSI: ffff95a4ee321098 RDI: ffffffff97913000
 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000046 R12: ffff95a4f2e8bd98
 R13: 0000000000000000 R14: ffff95a4ee321098 R15: 00000000009aa301
 FS:  00007f8565484740(0000) GS:ffff95a55aa40000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055876bd43d90 CR3: 00000000b76e6003 CR4: 00000000001706e0
 Call Trace:
  trace_print_lat_context+0x58/0x2d0
  ? cpumask_next+0x16/0x20
  print_trace_line+0x1a4/0x4f0
  ftrace_dump.cold+0xad/0x12c
  __handle_sysrq.cold+0x51/0x126
  write_sysrq_trigger+0x3f/0x4a
  proc_reg_write+0x53/0x80
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f8565579487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa
64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff
77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
 RSP: 002b:00007ffd40707948 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8565579487
 RDX: 0000000000000002 RSI: 000055876bd74de0 RDI: 0000000000000001
 RBP: 000055876bd74de0 R08: 000000000000000a R09: 0000000000000001
 R10: 000055876bdec280 R11: 0000000000000246 R12: 0000000000000002
 R13: 00007f856564a500 R14: 0000000000000002 R15: 00007f856564a700
 irq event stamp: 109958
 ---[ end trace 7aab5b7e51484b00 ]---

Not only fix the updating of the temp buffer, but also do not free the temp
buffer before a new buffer is allocated (there's no reason to not continue
to use the current temp buffer if an allocation fails).

Cc: stable@vger.kernel.org
Fixes: 8e99cf91b9 ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Reported-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-29 12:46:22 -04:00
Masami Hiramatsu
720dee53ad tracing/boot: Initialize per-instance event list in early boot
Initialize per-instance event list in early boot time (before
initializing instance directory on tracefs). This fixes boot-time
tracing to correctly handle the boot-time per-instance settings.

Link: https://lkml.kernel.org/r/160096560826.182763.17110991546046128881.stgit@devnote2

Fixes: 4114fbfd02 ("tracing: Enable creating new instance early boot")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-25 15:36:03 -04:00
Christoph Hellwig
fa01b1e973 block: add a bdev_is_partition helper
Add a littler helper to make the somewhat arcane bd_contains checks a
little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:18:57 -06:00
Jarkko Sakkinen
e9ffc8c1b8 kprobes: Use module_name() macro
It is advised to use module_name() macro instead of dereferencing mod->name
directly. This makes sense for consistencys sake and also it prevents a
hard dependency to CONFIG_MODULES.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200818050857.117998-1-jarkko.sakkinen@linux.intel.com
2020-09-24 15:55:49 +02:00
Linus Torvalds
eff48ddeab Tracing fixes:
- Check kprobe is enabled before unregistering from ftrace as it isn't
   registered when disabled.
 
 - Remove kprobes enabled via command-line that is on init text when freed.
 
 - Add missing RCU synchronization for ftrace trampoline symbols removed
   from kallsyms.
 
 - Free trampoline on error path if ftrace_startup() fails.
 
 - Give more space for the longer PID numbers in trace output.
 
 - Fix a possible double free in the histogram code.
 
 - A couple of fixes that were discovered by sparse.
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Merge tag 'trace-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Check kprobe is enabled before unregistering from ftrace as it isn't
   registered when disabled.

 - Remove kprobes enabled via command-line that is on init text when
   freed.

 - Add missing RCU synchronization for ftrace trampoline symbols removed
   from kallsyms.

 - Free trampoline on error path if ftrace_startup() fails.

 - Give more space for the longer PID numbers in trace output.

 - Fix a possible double free in the histogram code.

 - A couple of fixes that were discovered by sparse.

* tag 'trace-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  bootconfig: init: make xbc_namebuf static
  kprobes: tracing/kprobes: Fix to kill kprobes on initmem after boot
  tracing: fix double free
  ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer
  tracing: Make the space reserved for the pid wider
  ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms
  ftrace: Free the trampoline when ftrace_startup() fails
  kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
2020-09-22 09:08:33 -07:00
Masami Hiramatsu
ba0fbfbb21 tracing/boot, kprobe, synth: Initialize boot-time tracing earlier
Initialize boot-time tracing in core_initcall_sync instead of
fs_initcall, and initialize required tracers (kprobes and synth)
in core_initcall. This will allow the boot-time tracing to trace
__init code from the beginning of postcore_initcall stage.

Link: https://lkml.kernel.org/r/159974155727.478751.7486926132902849578.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu
4114fbfd02 tracing: Enable creating new instance early boot
Enable creating new trace_array instance in early boot stage.
If the instances directory is not created, postpone it until
the tracefs is initialized.

Link: https://lkml.kernel.org/r/159974154763.478751.6289753509587233103.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu
a838deab4e tracing: Enable adding dynamic events early stage
Split the event fields initialization from creating new event directory.
This allows the boot-time tracing to define dynamic events before
initializing events directory on tracefs.

Link: https://lkml.kernel.org/r/159974153790.478751.3475515065034825374.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu
ac343da7bc tracing: Define event fields early stage
Define event fields at early stage so that boot-time tracing can
access the event fields (like per-event filter setting).

Link: https://lkml.kernel.org/r/159974152862.478751.2023768466808361350.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu
3dd3aae32d tracing/uprobes: Support perf-style return probe
Support perf-style return probe ("SYMBOL%return") for uprobe events
as same as kprobe events does.

Link: https://lkml.kernel.org/r/159972814601.428528.7641183316212425445.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:03 -04:00
Masami Hiramatsu
4725cd8997 tracing/kprobes: Support perf-style return probe
Support perf-style return probe ("SYMBOL%return") for kprobe events.
This will allow boot-time tracing user to define a return probe event.

Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:03 -04:00
Masami Hiramatsu
8490db06f9 tracing/boot: Add per-instance tracing_on option support
Add per-instance tracing_on option, which will be useful with
traceon/traceoff event trigger actions. For example, if we
disable tracing_on by default and set traceon and traceoff on
a pair of events, we can trace functions between the pair of
events.

Link: https://lkml.kernel.org/r/159972811538.428528.2561315102284268611.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:03 -04:00
Davidlohr Bueso
40d14da383 fgraph: Convert ret_stack tasklist scanning to rcu
It seems that alloc_retstack_tasklist() can also take a lockless
approach for scanning the tasklist, instead of using the big global
tasklist_lock. For this we also kill another deprecated and rcu-unsafe
tsk->thread_group user replacing it with for_each_process_thread(),
maintaining semantics.

Here tasklist_lock does not protect anything other than the list
against concurrent fork/exit. And considering that the whole thing
is capped by FTRACE_RETSTACK_ALLOC_SIZE (32), it should not be a
problem to have a pontentially stale, yet stable, list. The task cannot
go away either, so we don't risk racing with ftrace_graph_exit_task()
which clears the retstack.

The tsk->ret_stack management is not protected by tasklist_lock, being
serialized with the corresponding publish/subscribe barriers against
concurrent ftrace_push_return_trace(). In addition this plays nicer
with cachelines by avoiding two atomic ops in the uncontended case.

Link: https://lkml.kernel.org/r/20200907013326.9870-1-dave@stgolabs.net

Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Dan Carpenter
eb8d8b4c98 tracing: remove a pointless assignment
The "tr" is a stack variable so setting it to NULL before a return is
a no-op.  Delete the assignment.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Jarkko Sakkinen
f3d3642661 kprobes: Use module_name() macro
It is advised to use module_name() macro instead of dereferencing mod->name
directly. This makes sense for consistencys sake and also it prevents a
hard dependency to CONFIG_MODULES.

Link: https://lkml.kernel.org/r/20200818050857.117998-1-jarkko.sakkinen@linux.intel.com

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mm@kvack.org
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Xianting Tian
b427e765bd tracing: Use __this_cpu_read() in trace_buffered_event_enable()
The code is executed with preemption disabled, so it's
safe to use __this_cpu_read().

Link: https://lkml.kernel.org/r/20200813112803.12256-1-tian.xianting@h3c.com

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00