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5872 commits

Author SHA1 Message Date
Steven Rostedt (Google)
9034c87d61 tracing: Have trace_event_file have ref counters
commit bb32500fb9 upstream

The following can crash the kernel:

 # cd /sys/kernel/tracing
 # echo 'p:sched schedule' > kprobe_events
 # exec 5>>events/kprobes/sched/enable
 # > kprobe_events
 # exec 5>&-

The above commands:

 1. Change directory to the tracefs directory
 2. Create a kprobe event (doesn't matter what one)
 3. Open bash file descriptor 5 on the enable file of the kprobe event
 4. Delete the kprobe event (removes the files too)
 5. Close the bash file descriptor 5

The above causes a crash!

 BUG: kernel NULL pointer dereference, address: 0000000000000028
 #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: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
 RIP: 0010:tracing_release_file_tr+0xc/0x50

What happens here is that the kprobe event creates a trace_event_file
"file" descriptor that represents the file in tracefs to the event. It
maintains state of the event (is it enabled for the given instance?).
Opening the "enable" file gets a reference to the event "file" descriptor
via the open file descriptor. When the kprobe event is deleted, the file is
also deleted from the tracefs system which also frees the event "file"
descriptor.

But as the tracefs file is still opened by user space, it will not be
totally removed until the final dput() is called on it. But this is not
true with the event "file" descriptor that is already freed. If the user
does a write to or simply closes the file descriptor it will reference the
event "file" descriptor that was just freed, causing a use-after-free bug.

To solve this, add a ref count to the event "file" descriptor as well as a
new flag called "FREED". The "file" will not be freed until the last
reference is released. But the FREE flag will be set when the event is
removed to prevent any more modifications to that event from happening,
even if there's still a reference to the event "file" descriptor.

Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: f5ca233e2e ("tracing: Increase trace array ref count on enable and filter files")
Reported-by: Beau Belgrave <beaub@linux.microsoft.com>
Tested-by: Beau Belgrave <beaub@linux.microsoft.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-08 11:56:21 +01:00
Andrii Nakryiko
926fe783c8 tracing/kprobes: Fix symbol counting logic by looking at modules as well
Recent changes to count number of matching symbols when creating
a kprobe event failed to take into account kernel modules. As such, it
breaks kprobes on kernel module symbols, by assuming there is no match.

Fix this my calling module_kallsyms_on_each_symbol() in addition to
kallsyms_on_each_match_symbol() to perform a proper counting.

Link: https://lore.kernel.org/all/20231027233126.2073148-1-andrii@kernel.org/

Cc: Francis Laniel <flaniel@linux.microsoft.com>
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: b022f0c7e4 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-28 09:50:42 +09:00
Yujie Liu
e0f831836c tracing/kprobes: Fix the description of variable length arguments
Fix the following kernel-doc warnings:

kernel/trace/trace_kprobe.c:1029: warning: Excess function parameter 'args' description in '__kprobe_event_gen_cmd_start'
kernel/trace/trace_kprobe.c:1097: warning: Excess function parameter 'args' description in '__kprobe_event_add_fields'

Refer to the usage of variable length arguments elsewhere in the kernel
code, "@..." is the proper way to express it in the description.

Link: https://lore.kernel.org/all/20231027041315.2613166-1-yujie.liu@intel.com/

Fixes: 2a588dd1d5 ("tracing: Add kprobe event command generation functions")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310190437.paI6LYJF-lkp@intel.com/
Signed-off-by: Yujie Liu <yujie.liu@intel.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-27 22:20:28 +09:00
Francis Laniel
b022f0c7e4 tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols
When a kprobe is attached to a function that's name is not unique (is
static and shares the name with other functions in the kernel), the
kprobe is attached to the first function it finds. This is a bug as the
function that it is attaching to is not necessarily the one that the
user wants to attach to.

Instead of blindly picking a function to attach to what is ambiguous,
error with EADDRNOTAVAIL to let the user know that this function is not
unique, and that the user must use another unique function with an
address offset to get to the function they want to attach to.

Link: https://lore.kernel.org/all/20231020104250.9537-2-flaniel@linux.microsoft.com/

Cc: stable@vger.kernel.org
Fixes: 413d37d1eb ("tracing: Add kprobe-based event tracer")
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Francis Laniel <flaniel@linux.microsoft.com>
Link: https://lore.kernel.org/lkml/20230819101105.b0c104ae4494a7d1f2eea742@kernel.org/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-20 22:10:41 +09:00
Masami Hiramatsu (Google)
700b2b4397 fprobe: Fix to ensure the number of active retprobes is not zero
The number of active retprobes can be zero but it is not acceptable,
so return EINVAL error if detected.

Link: https://lore.kernel.org/all/169750018550.186853.11198884812017796410.stgit@devnote2/

Reported-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Closes: https://lore.kernel.org/all/20231016222103.cb9f426edc60220eabd8aa6a@kernel.org/
Fixes: 5b0ab78998 ("fprobe: Add exit_handler support")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-17 10:22:42 +09:00
Beau Belgrave
2de9ee9405 tracing/user_events: Align set_bit() address for all archs
All architectures should use a long aligned address passed to set_bit().
User processes can pass either a 32-bit or 64-bit sized value to be
updated when tracing is enabled when on a 64-bit kernel. Both cases are
ensured to be naturally aligned, however, that is not enough. The
address must be long aligned without affecting checks on the value
within the user process which require different adjustments for the bit
for little and big endian CPUs.

Add a compat flag to user_event_enabler that indicates when a 32-bit
value is being used on a 64-bit kernel. Long align addresses and correct
the bit to be used by set_bit() to account for this alignment. Ensure
compat flags are copied during forks and used during deletion clears.

Link: https://lore.kernel.org/linux-trace-kernel/20230925230829.341-2-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/20230914131102.179100-1-cleger@rivosinc.com/

Cc: stable@vger.kernel.org
Fixes: 7235759084 ("tracing/user_events: Use remote writes for event enablement")
Reported-by: Clément Léger <cleger@rivosinc.com>
Suggested-by: Clément Léger <cleger@rivosinc.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30 16:25:41 -04:00
Clément Léger
23cce5f254 tracing: relax trace_event_eval_update() execution with cond_resched()
When kernel is compiled without preemption, the eval_map_work_func()
(which calls trace_event_eval_update()) will not be preempted up to its
complete execution. This can actually cause a problem since if another
CPU call stop_machine(), the call will have to wait for the
eval_map_work_func() function to finish executing in the workqueue
before being able to be scheduled. This problem was observe on a SMP
system at boot time, when the CPU calling the initcalls executed
clocksource_done_booting() which in the end calls stop_machine(). We
observed a 1 second delay because one CPU was executing
eval_map_work_func() and was not preempted by the stop_machine() task.

Adding a call to cond_resched() in trace_event_eval_update() allows
other tasks to be executed and thus continue working asynchronously
like before without blocking any pending task at boot time.

Link: https://lore.kernel.org/linux-trace-kernel/20230929191637.416931-1-cleger@rivosinc.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30 16:24:55 -04:00
Steven Rostedt (Google)
1e0cb399c7 ring-buffer: Update "shortest_full" in polling
It was discovered that the ring buffer polling was incorrectly stating
that read would not block, but that's because polling did not take into
account that reads will block if the "buffer-percent" was set. Instead,
the ring buffer polling would say reads would not block if there was any
data in the ring buffer. This was incorrect behavior from a user space
point of view. This was fixed by commit 42fb0a1e84 by having the polling
code check if the ring buffer had more data than what the user specified
"buffer percent" had.

The problem now is that the polling code did not register itself to the
writer that it wanted to wait for a specific "full" value of the ring
buffer. The result was that the writer would wake the polling waiter
whenever there was a new event. The polling waiter would then wake up, see
that there's not enough data in the ring buffer to notify user space and
then go back to sleep. The next event would wake it up again.

Before the polling fix was added, the code would wake up around 100 times
for a hackbench 30 benchmark. After the "fix", due to the constant waking
of the writer, it would wake up over 11,0000 times! It would never leave
the kernel, so the user space behavior was still "correct", but this
definitely is not the desired effect.

To fix this, have the polling code add what it's waiting for to the
"shortest_full" variable, to tell the writer not to wake it up if the
buffer is not as full as it expects to be.

Note, after this fix, it appears that the waiter is now woken up around 2x
the times it was before (~200). This is a tremendous improvement from the
11,000 times, but I will need to spend some time to see why polling is
more aggressive in its wakeups than the read blocking code.

Link: https://lore.kernel.org/linux-trace-kernel/20230929180113.01c2cae3@rorschach.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 42fb0a1e84 ("tracing/ring-buffer: Have polling block on watermark")
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Tested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30 16:17:34 -04:00
Linus Torvalds
5edc6bb321 Tracing fixes for 6.6-rc2:
- Fix the "bytes" output of the per_cpu stat file
   The tracefs/per_cpu/cpu*/stats "bytes" was giving bogus values as the
   accounting was not accurate. It is suppose to show how many used bytes are
   still in the ring buffer, but even when the ring buffer was empty it would
   still show there were bytes used.
 
 - Fix a bug in eventfs where reading a dynamic event directory (open) and then
   creating a dynamic event that goes into that diretory screws up the accounting.
   On close, the newly created event dentry will get a "dput" without ever having
   a "dget" done for it. The fix is to allocate an array on dir open to save what
   dentries were actually "dget" on, and what ones to "dput" on close.
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Merge tag 'trace-v6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix the "bytes" output of the per_cpu stat file

   The tracefs/per_cpu/cpu*/stats "bytes" was giving bogus values as the
   accounting was not accurate. It is suppose to show how many used
   bytes are still in the ring buffer, but even when the ring buffer was
   empty it would still show there were bytes used.

 - Fix a bug in eventfs where reading a dynamic event directory (open)
   and then creating a dynamic event that goes into that diretory screws
   up the accounting.

   On close, the newly created event dentry will get a "dput" without
   ever having a "dget" done for it. The fix is to allocate an array on
   dir open to save what dentries were actually "dget" on, and what ones
   to "dput" on close.

* tag 'trace-v6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Remember what dentries were created on dir open
  ring-buffer: Fix bytes info in per_cpu buffer stats
2023-09-24 13:55:34 -07:00
Zheng Yejian
45d99ea451 ring-buffer: Fix bytes info in per_cpu buffer stats
The 'bytes' info in file 'per_cpu/cpu<X>/stats' means the number of
bytes in cpu buffer that have not been consumed. However, currently
after consuming data by reading file 'trace_pipe', the 'bytes' info
was not changed as expected.

  # cat per_cpu/cpu0/stats
  entries: 0
  overrun: 0
  commit overrun: 0
  bytes: 568             <--- 'bytes' is problematical !!!
  oldest event ts:  8651.371479
  now ts:  8653.912224
  dropped events: 0
  read events: 8

The root cause is incorrect stat on cpu_buffer->read_bytes. To fix it:
  1. When stat 'read_bytes', account consumed event in rb_advance_reader();
  2. When stat 'entries_bytes', exclude the discarded padding event which
     is smaller than minimum size because it is invisible to reader. Then
     use rb_page_commit() instead of BUF_PAGE_SIZE at where accounting for
     page-based read/remove/overrun.

Also correct the comments of ring_buffer_bytes_cpu() in this patch.

Link: https://lore.kernel.org/linux-trace-kernel/20230921125425.1708423-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Fixes: c64e148a3b ("trace: Add ring buffer stats to measure rate of events")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-22 16:57:14 -04:00
David S. Miller
1612cc4b14 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================

The following pull-request contains BPF updates for your *net* tree.

We've added 21 non-merge commits during the last 8 day(s) which contain
a total of 21 files changed, 450 insertions(+), 36 deletions(-).

The main changes are:

1) Adjust bpf_mem_alloc buckets to match ksize(), from Hou Tao.

2) Check whether override is allowed in kprobe mult, from Jiri Olsa.

3) Fix btf_id symbol generation with ld.lld, from Jiri and Nick.

4) Fix potential deadlock when using queue and stack maps from NMI, from Toke Høiland-Jørgensen.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Alan Maguire, Biju Das, Björn Töpel, Dan Carpenter, Daniel Borkmann,
Eduard Zingerman, Hsin-Wei Hung, Marcus Seyfarth, Nathan Chancellor,
Satya Durga Srinivasu Prabhala, Song Liu, Stephen Rothwell
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-16 11:16:00 +01:00
Jiri Olsa
57eb5e1c5c bpf: Fix uprobe_multi get_pid_task error path
Dan reported Smatch static checker warning due to missing error
value set in uprobe multi link's get_pid_task error path.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/bpf/c5ffa7c0-6b06-40d5-aca2-63833b5cd9af@moroto.mountain/
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230915101420.1193800-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-15 10:32:40 -07:00
Linus Torvalds
99214f6778 Tracing fixes for 6.6:
- Add missing LOCKDOWN checks for eventfs callers
   When LOCKDOWN is active for tracing, it causes inconsistent state
   when some functions succeed and others fail.
 
 - Use dput() to free the top level eventfs descriptor
   There was a race between accesses and freeing it.
 
 - Fix a long standing bug that eventfs exposed due to changing timings
   by dynamically creating files. That is, If a event file is opened
   for an instance, there's nothing preventing the instance from being
   removed which will make accessing the files cause use-after-free bugs.
 
 - Fix a ring buffer race that happens when iterating over the ring
   buffer while writers are active. Check to make sure not to read
   the event meta data if it's beyond the end of the ring buffer sub buffer.
 
 - Fix the print trigger that disappeared because the test to create it
   was looking for the event dir field being filled, but now it has the
   "ef" field filled for the eventfs structure.
 
 - Remove the unused "dir" field from the event structure.
 
 - Fix the order of the trace_dynamic_info as it had it backwards for the
   offset and len fields for which one was for which endianess.
 
 - Fix NULL pointer dereference with eventfs_remove_rec()
   If an allocation fails in one of the eventfs_add_*() functions,
   the caller of it in event_subsystem_dir() or event_create_dir()
   assigns the result to the structure. But it's assigning the ERR_PTR
   and not NULL. This was passed to eventfs_remove_rec() which expects
   either a good pointer or a NULL, not ERR_PTR. The fix is to not
   assign the ERR_PTR to the structure, but to keep it NULL on error.
 
 - Fix list_for_each_rcu() to use list_for_each_srcu() in
   dcache_dir_open_wrapper(). One iteration of the code used RCU
   but because it had to call sleepable code, it had to be changed
   to use SRCU, but one of the iterations was missed.
 
 - Fix synthetic event print function to use "as_u64" instead of
   passing in a pointer to the union. To fix big/little endian issues,
   the u64 that represented several types was turned into a union to
   define the types properly.
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Merge tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Add missing LOCKDOWN checks for eventfs callers

   When LOCKDOWN is active for tracing, it causes inconsistent state
   when some functions succeed and others fail.

 - Use dput() to free the top level eventfs descriptor

   There was a race between accesses and freeing it.

 - Fix a long standing bug that eventfs exposed due to changing timings
   by dynamically creating files. That is, If a event file is opened for
   an instance, there's nothing preventing the instance from being
   removed which will make accessing the files cause use-after-free
   bugs.

 - Fix a ring buffer race that happens when iterating over the ring
   buffer while writers are active. Check to make sure not to read the
   event meta data if it's beyond the end of the ring buffer sub buffer.

 - Fix the print trigger that disappeared because the test to create it
   was looking for the event dir field being filled, but now it has the
   "ef" field filled for the eventfs structure.

 - Remove the unused "dir" field from the event structure.

 - Fix the order of the trace_dynamic_info as it had it backwards for
   the offset and len fields for which one was for which endianess.

 - Fix NULL pointer dereference with eventfs_remove_rec()

   If an allocation fails in one of the eventfs_add_*() functions, the
   caller of it in event_subsystem_dir() or event_create_dir() assigns
   the result to the structure. But it's assigning the ERR_PTR and not
   NULL. This was passed to eventfs_remove_rec() which expects either a
   good pointer or a NULL, not ERR_PTR. The fix is to not assign the
   ERR_PTR to the structure, but to keep it NULL on error.

 - Fix list_for_each_rcu() to use list_for_each_srcu() in
   dcache_dir_open_wrapper(). One iteration of the code used RCU but
   because it had to call sleepable code, it had to be changed to use
   SRCU, but one of the iterations was missed.

 - Fix synthetic event print function to use "as_u64" instead of passing
   in a pointer to the union. To fix big/little endian issues, the u64
   that represented several types was turned into a union to define the
   types properly.

* tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Fix the NULL pointer dereference bug in eventfs_remove_rec()
  tracefs/eventfs: Use list_for_each_srcu() in dcache_dir_open_wrapper()
  tracing/synthetic: Print out u64 values properly
  tracing/synthetic: Fix order of struct trace_dynamic_info
  selftests/ftrace: Fix dependencies for some of the synthetic event tests
  tracing: Remove unused trace_event_file dir field
  tracing: Use the new eventfs descriptor for print trigger
  ring-buffer: Do not attempt to read past "commit"
  tracefs/eventfs: Free top level files on removal
  ring-buffer: Avoid softlockup in ring_buffer_resize()
  tracing: Have event inject files inc the trace array ref count
  tracing: Have option files inc the trace array ref count
  tracing: Have current_trace inc the trace array ref count
  tracing: Have tracing_max_latency inc the trace array ref count
  tracing: Increase trace array ref count on enable and filter files
  tracefs/eventfs: Use dput to free the toplevel events directory
  tracefs/eventfs: Add missing lockdown checks
  tracefs: Add missing lockdown check to tracefs_create_dir()
2023-09-13 11:30:11 -07:00
Jinjie Ruan
c8414dab16 eventfs: Fix the NULL pointer dereference bug in eventfs_remove_rec()
Inject fault while probing btrfs.ko, if kstrdup() fails in
eventfs_prepare_ef() in eventfs_add_dir(), it will return ERR_PTR
to assign file->ef. But the eventfs_remove() check NULL in
trace_module_remove_events(), which causes the below NULL
pointer dereference.

As both Masami and Steven suggest, allocater side should handle the
error carefully and remove it, so fix the places where it failed.

 Could not create tracefs 'raid56_write' directory
 Btrfs loaded, zoned=no, fsverity=no
 Unable to handle kernel NULL pointer dereference at virtual address 000000000000001c
 Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000102544000
 [000000000000001c] pgd=0000000000000000, p4d=0000000000000000
 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Modules linked in: btrfs(-) libcrc32c xor xor_neon raid6_pq cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: btrfs]
 CPU: 15 PID: 1343 Comm: rmmod Tainted: G                 N 6.5.0+ #40
 Hardware name: linux,dummy-virt (DT)
 pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : eventfs_remove_rec+0x24/0xc0
 lr : eventfs_remove+0x68/0x1d8
 sp : ffff800082d63b60
 x29: ffff800082d63b60 x28: ffffb84b80ddd00c x27: ffffb84b3054ba40
 x26: 0000000000000002 x25: ffff800082d63bf8 x24: ffffb84b8398e440
 x23: ffffb84b82af3000 x22: dead000000000100 x21: dead000000000122
 x20: ffff800082d63bf8 x19: fffffffffffffff4 x18: ffffb84b82508820
 x17: 0000000000000000 x16: 0000000000000000 x15: 000083bc876a3166
 x14: 000000000000006d x13: 000000000000006d x12: 0000000000000000
 x11: 0000000000000001 x10: 00000000000017e0 x9 : 0000000000000001
 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffb84b84289804
 x5 : 0000000000000000 x4 : 9696969696969697 x3 : ffff33a5b7601f38
 x2 : 0000000000000000 x1 : ffff800082d63bf8 x0 : fffffffffffffff4
 Call trace:
  eventfs_remove_rec+0x24/0xc0
  eventfs_remove+0x68/0x1d8
  remove_event_file_dir+0x88/0x100
  event_remove+0x140/0x15c
  trace_module_notify+0x1fc/0x230
  notifier_call_chain+0x98/0x17c
  blocking_notifier_call_chain+0x4c/0x74
  __arm64_sys_delete_module+0x1a4/0x298
  invoke_syscall+0x44/0x100
  el0_svc_common.constprop.1+0x68/0xe0
  do_el0_svc+0x1c/0x28
  el0_svc+0x3c/0xc4
  el0t_64_sync_handler+0xa0/0xc4
  el0t_64_sync+0x174/0x178
 Code: 5400052c a90153b3 aa0003f3 aa0103f4 (f9401400)
 ---[ end trace 0000000000000000 ]---
 Kernel panic - not syncing: Oops: Fatal exception
 SMP: stopping secondary CPUs
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Kernel Offset: 0x384b00c00000 from 0xffff800080000000
 PHYS_OFFSET: 0xffffcc5b80000000
 CPU features: 0x88000203,3c020000,1000421b
 Memory Limit: none
 Rebooting in 1 seconds..

Link: https://lore.kernel.org/linux-trace-kernel/20230912134752.1838524-1-ruanjinjie@huawei.com
Link: https://lore.kernel.org/all/20230912025808.668187-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230911052818.1020547-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230909072817.182846-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230908074816.3724716-1-ruanjinjie@huawei.com/

Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 5bdcd5f533 ("eventfs: Implement removal of meta data from eventfs")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-12 09:57:01 -04:00
Tero Kristo
62663b8496 tracing/synthetic: Print out u64 values properly
The synth traces incorrectly print pointer to the synthetic event values
instead of the actual value when using u64 type. Fix by addressing the
contents of the union properly.

Link: https://lore.kernel.org/linux-trace-kernel/20230911141704.3585965-1-tero.kristo@linux.intel.com

Fixes: ddeea494a1 ("tracing/synthetic: Use union instead of casts")
Cc: stable@vger.kernel.org
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-11 18:23:10 -04:00
Steven Rostedt (Google)
6fdac58c56 tracing: Remove unused trace_event_file dir field
Now that eventfs structure is used to create the events directory via the
eventfs dynamically allocate code, the "dir" field of the trace_event_file
structure is no longer used. Remove it.

Link: https://lkml.kernel.org/r/20230908022001.580400115@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-08 23:13:02 -04:00
Steven Rostedt (Google)
1ef26d8b2c tracing: Use the new eventfs descriptor for print trigger
The check to create the print event "trigger" was using the obsolete "dir"
value of the trace_event_file to determine if it should create the trigger
or not. But that value will now be NULL because it uses the event file
descriptor.

Change it to test the "ef" field of the trace_event_file structure so that
the trace_marker "trigger" file appears again.

Link: https://lkml.kernel.org/r/20230908022001.371815239@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 27152bceea ("eventfs: Move tracing/events to eventfs")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-08 23:13:01 -04:00
Steven Rostedt (Google)
95a404bd60 ring-buffer: Do not attempt to read past "commit"
When iterating over the ring buffer while the ring buffer is active, the
writer can corrupt the reader. There's barriers to help detect this and
handle it, but that code missed the case where the last event was at the
very end of the page and has only 4 bytes left.

The checks to detect the corruption by the writer to reads needs to see the
length of the event. If the length in the first 4 bytes is zero then the
length is stored in the second 4 bytes. But if the writer is in the process
of updating that code, there's a small window where the length in the first
4 bytes could be zero even though the length is only 4 bytes. That will
cause rb_event_length() to read the next 4 bytes which could happen to be off the
allocated page.

To protect against this, fail immediately if the next event pointer is
less than 8 bytes from the end of the commit (last byte of data), as all
events must be a minimum of 8 bytes anyway.

Link: https://lore.kernel.org/all/20230905141245.26470-1-Tze-nan.Wu@mediatek.com/
Link: https://lore.kernel.org/linux-trace-kernel/20230907122820.0899019c@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reported-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-08 23:12:19 -04:00
Jiri Olsa
41bc46c12a bpf: Add override check to kprobe multi link attach
Currently the multi_kprobe link attach does not check error
injection list for programs with bpf_override_return helper
and allows them to attach anywhere. Adding the missing check.

Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org
2023-09-08 16:53:10 -07:00
Zheng Yejian
f6bd2c9248 ring-buffer: Avoid softlockup in ring_buffer_resize()
When user resize all trace ring buffer through file 'buffer_size_kb',
then in ring_buffer_resize(), kernel allocates buffer pages for each
cpu in a loop.

If the kernel preemption model is PREEMPT_NONE and there are many cpus
and there are many buffer pages to be allocated, it may not give up cpu
for a long time and finally cause a softlockup.

To avoid it, call cond_resched() after each cpu buffer allocation.

Link: https://lore.kernel.org/linux-trace-kernel/20230906081930.3939106-1-zhengyejian1@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:54 -04:00
Steven Rostedt (Google)
e5c624f027 tracing: Have event inject files inc the trace array ref count
The event inject files add events for a specific trace array. For an
instance, if the file is opened and the instance is deleted, reading or
writing to the file will cause a use after free.

Up the ref count of the trace_array when a event inject file is opened.

Link: https://lkml.kernel.org/r/20230907024804.292337868@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 6c3edaf9fd ("tracing: Introduce trace event injection")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:54 -04:00
Steven Rostedt (Google)
7e2cfbd2d3 tracing: Have option files inc the trace array ref count
The option files update the options for a given trace array. For an
instance, if the file is opened and the instance is deleted, reading or
writing to the file will cause a use after free.

Up the ref count of the trace_array when an option file is opened.

Link: https://lkml.kernel.org/r/20230907024804.086679464@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:54 -04:00
Steven Rostedt (Google)
9b37febc57 tracing: Have current_trace inc the trace array ref count
The current_trace updates the trace array tracer. For an instance, if the
file is opened and the instance is deleted, reading or writing to the file
will cause a use after free.

Up the ref count of the trace array when current_trace is opened.

Link: https://lkml.kernel.org/r/20230907024803.877687227@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:53 -04:00
Steven Rostedt (Google)
7d660c9b2b tracing: Have tracing_max_latency inc the trace array ref count
The tracing_max_latency file points to the trace_array max_latency field.
For an instance, if the file is opened and the instance is deleted,
reading or writing to the file will cause a use after free.

Up the ref count of the trace_array when tracing_max_latency is opened.

Link: https://lkml.kernel.org/r/20230907024803.666889383@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:53 -04:00
Steven Rostedt (Google)
f5ca233e2e tracing: Increase trace array ref count on enable and filter files
When the trace event enable and filter files are opened, increment the
trace array ref counter, otherwise they can be accessed when the trace
array is being deleted. The ref counter keeps the trace array from being
deleted while those files are opened.

Link: https://lkml.kernel.org/r/20230907024803.456187066@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:05:46 -04:00
Linus Torvalds
b70100f2e6 Probes updates for v6.6:
- kprobes: use struct_size() for variable size kretprobe_instance
   data structure.
 
 - eprobe: Simplify trace_eprobe list iteration.
 
 - probe events: Data structure field access support on BTF argument.
   . Update BTF argument support on the functions in the kernel loadable
     modules (only loaded modules are supported).
   . Move generic BTF access function (search function prototype and get
     function parameters) to a separated file.
   . Add a function to search a member of data structure in BTF.
   . Support accessing BTF data structure member from probe args by
     C-like arrow('->') and dot('.') operators. e.g.
     't sched_switch next=next->pid vruntime=next->se.vruntime'
   . Support accessing BTF data structure member from $retval. e.g.
       'f getname_flags%return +0($retval->name):string'
   . Add string type checking if BTF type info is available.
     This will reject if user specify ":string" type for non "char
     pointer" type.
   . Automatically assume the fprobe event as a function return event
     if $retval is used.
 
 - selftests/ftrace: Add BTF data field access test cases.
 
 - Documentation: Update fprobe event example with BTF data field.
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Merge tag 'probes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:

 - kprobes: use struct_size() for variable size kretprobe_instance data
   structure.

 - eprobe: Simplify trace_eprobe list iteration.

 - probe events: Data structure field access support on BTF argument.

     - Update BTF argument support on the functions in the kernel
       loadable modules (only loaded modules are supported).

     - Move generic BTF access function (search function prototype and
       get function parameters) to a separated file.

     - Add a function to search a member of data structure in BTF.

     - Support accessing BTF data structure member from probe args by
       C-like arrow('->') and dot('.') operators. e.g.
          't sched_switch next=next->pid vruntime=next->se.vruntime'

     - Support accessing BTF data structure member from $retval. e.g.
          'f getname_flags%return +0($retval->name):string'

     - Add string type checking if BTF type info is available. This will
       reject if user specify ":string" type for non "char pointer"
       type.

     - Automatically assume the fprobe event as a function return event
       if $retval is used.

 - selftests/ftrace: Add BTF data field access test cases.

 - Documentation: Update fprobe event example with BTF data field.

* tag 'probes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Update fprobe event example with BTF field
  selftests/ftrace: Add BTF fields access testcases
  tracing/fprobe-event: Assume fprobe is a return event by $retval
  tracing/probes: Add string type check with BTF
  tracing/probes: Support BTF field access from $retval
  tracing/probes: Support BTF based data structure field access
  tracing/probes: Add a function to search a member of a struct/union
  tracing/probes: Move finding func-proto API and getting func-param API to trace_btf
  tracing/probes: Support BTF argument on module functions
  tracing/eprobe: Iterate trace_eprobe directly
  kernel: kprobes: Use struct_size()
2023-09-02 11:10:50 -07:00
Valentin Schneider
cbb557ba92 tracing/filters: Fix coding style issues
Recent commits have introduced some coding style issues, fix those up.

Link: https://lkml.kernel.org/r/20230901151039.125186-5-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:27:23 -04:00
Valentin Schneider
2900bcbee3 tracing/filters: Change parse_pred() cpulist ternary into an if block
Review comments noted that an if block would be clearer than a ternary, so
swap it out.

No change in behaviour intended

Link: https://lkml.kernel.org/r/20230901151039.125186-4-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:27:22 -04:00
Valentin Schneider
1caf7adb9e tracing/filters: Fix double-free of struct filter_pred.mask
When a cpulist filter is found to contain a single CPU, that CPU is saved
as a scalar and the backing cpumask storage is freed.

Also NULL the mask to avoid a double-free once we get down to
free_predicate().

Link: https://lkml.kernel.org/r/20230901151039.125186-3-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:27:22 -04:00
Valentin Schneider
9af4058493 tracing/filters: Fix error-handling of cpulist parsing buffer
parse_pred() allocates a string buffer to parse the user-provided cpulist,
but doesn't check the allocation result nor does it free the buffer once it
is no longer needed.

Add an allocation check, and free the buffer as soon as it is no longer
needed.

Link: https://lkml.kernel.org/r/20230901151039.125186-2-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:27:22 -04:00
Brian Foster
3d07fa1dd1 tracing: Zero the pipe cpumask on alloc to avoid spurious -EBUSY
The pipe cpumask used to serialize opens between the main and percpu
trace pipes is not zeroed or initialized. This can result in
spurious -EBUSY returns if underlying memory is not fully zeroed.
This has been observed by immediate failure to read the main
trace_pipe file on an otherwise newly booted and idle system:

 # cat /sys/kernel/debug/tracing/trace_pipe
 cat: /sys/kernel/debug/tracing/trace_pipe: Device or resource busy

Zero the allocation of pipe_cpumask to avoid the problem.

Link: https://lore.kernel.org/linux-trace-kernel/20230831125500.986862-1-bfoster@redhat.com

Cc: stable@vger.kernel.org
Fixes: c2489bb7e6 ("tracing: Introduce pipe_cpumask to avoid race on trace_pipes")
Reviewed-by: Zheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:26:07 -04:00
Ruan Jinjie
2a30dbcbef ftrace: Use LIST_HEAD to initialize clear_hash
Use LIST_HEAD() to initialize clear_hash instead of open-coding it.

Link: https://lore.kernel.org/linux-trace-kernel/20230809071551.913041-1-ruanjinjie@huawei.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:18:38 -04:00
Levi Yun
1351148904 ftrace: Use within_module to check rec->ip within specified module.
within_module_core && within_module_init condition is same to
within module but it's more readable.

Use within_module instead of former condition to check rec->ip
within specified module area or not.

Link: https://lore.kernel.org/linux-trace-kernel/20230803205236.32201-1-ppbuk5246@gmail.com

Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:17:10 -04:00
Zheng Yejian
3163f635b2 tracing: Fix race issue between cpu buffer write and swap
Warning happened in rb_end_commit() at code:
	if (RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)))

  WARNING: CPU: 0 PID: 139 at kernel/trace/ring_buffer.c:3142
	rb_commit+0x402/0x4a0
  Call Trace:
   ring_buffer_unlock_commit+0x42/0x250
   trace_buffer_unlock_commit_regs+0x3b/0x250
   trace_event_buffer_commit+0xe5/0x440
   trace_event_buffer_reserve+0x11c/0x150
   trace_event_raw_event_sched_switch+0x23c/0x2c0
   __traceiter_sched_switch+0x59/0x80
   __schedule+0x72b/0x1580
   schedule+0x92/0x120
   worker_thread+0xa0/0x6f0

It is because the race between writing event into cpu buffer and swapping
cpu buffer through file per_cpu/cpu0/snapshot:

  Write on CPU 0             Swap buffer by per_cpu/cpu0/snapshot on CPU 1
  --------                   --------
                             tracing_snapshot_write()
                               [...]

  ring_buffer_lock_reserve()
    cpu_buffer = buffer->buffers[cpu]; // 1. Suppose find 'cpu_buffer_a';
    [...]
    rb_reserve_next_event()
      [...]

                               ring_buffer_swap_cpu()
                                 if (local_read(&cpu_buffer_a->committing))
                                     goto out_dec;
                                 if (local_read(&cpu_buffer_b->committing))
                                     goto out_dec;
                                 buffer_a->buffers[cpu] = cpu_buffer_b;
                                 buffer_b->buffers[cpu] = cpu_buffer_a;
                                 // 2. cpu_buffer has swapped here.

      rb_start_commit(cpu_buffer);
      if (unlikely(READ_ONCE(cpu_buffer->buffer)
          != buffer)) { // 3. This check passed due to 'cpu_buffer->buffer'
        [...]           //    has not changed here.
        return NULL;
      }
                                 cpu_buffer_b->buffer = buffer_a;
                                 cpu_buffer_a->buffer = buffer_b;
                                 [...]

      // 4. Reserve event from 'cpu_buffer_a'.

  ring_buffer_unlock_commit()
    [...]
    cpu_buffer = buffer->buffers[cpu]; // 5. Now find 'cpu_buffer_b' !!!
    rb_commit(cpu_buffer)
      rb_end_commit()  // 6. WARN for the wrong 'committing' state !!!

Based on above analysis, we can easily reproduce by following testcase:
  ``` bash
  #!/bin/bash

  dmesg -n 7
  sysctl -w kernel.panic_on_warn=1
  TR=/sys/kernel/tracing
  echo 7 > ${TR}/buffer_size_kb
  echo "sched:sched_switch" > ${TR}/set_event
  while [ true ]; do
          echo 1 > ${TR}/per_cpu/cpu0/snapshot
  done &
  while [ true ]; do
          echo 1 > ${TR}/per_cpu/cpu0/snapshot
  done &
  while [ true ]; do
          echo 1 > ${TR}/per_cpu/cpu0/snapshot
  done &
  ```

To fix it, IIUC, we can use smp_call_function_single() to do the swap on
the target cpu where the buffer is located, so that above race would be
avoided.

Link: https://lore.kernel.org/linux-trace-kernel/20230831132739.4070878-1-zhengyejian1@huawei.com

Cc: <mhiramat@kernel.org>
Fixes: f1affcaaa8 ("tracing: Add snapshot in the per_cpu trace directories")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:00:00 -04:00
Mikhail Kobuk
2cf0dee989 tracing: Remove extra space at the end of hwlat_detector/mode
Space is printed after each mode value including the last one:
$ echo \"$(sudo cat /sys/kernel/tracing/hwlat_detector/mode)\"
"none [round-robin] per-cpu "

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Link: https://lore.kernel.org/linux-trace-kernel/20230825103432.7750-1-m.kobuk@ispras.ru

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 8fa826b734 ("trace/hwlat: Implement the mode config option")
Signed-off-by: Mikhail Kobuk <m.kobuk@ispras.ru>
Reviewed-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-01 21:00:00 -04:00
Linus Torvalds
34232fcfe9 Tracing updates for 6.6:
User visible changes:
 
   - Added a way to easier filter with cpumasks:
      # echo 'cpumask & CPUS{17-42}' > /sys/kernel/tracing/events/ipi_send_cpumask/filter
 
   - Show actual size of ring buffer after modifying the ring buffer size via
     buffer_size_kb. Currently it just returns what was written, but the actual
     size rounds up to the sub buffer size. Show that real size instead.
 
  Major changes:
 
   - Added "eventfs". This is the code that handles the inodes and dentries of
     tracefs/events directory. As there are thousands of events, and each event
     has several inodes and dentries that currently exist even when tracing is
     never used, they take up precious memory. Instead, eventfs will allocate
     the inodes and dentries in a JIT way (similar to what procfs does). There
     is now metadata that handles the events and subdirectories, and will create
     the inodes and dentries when they are used.
 
     Note, I also have patches that remove the subdirectory meta data, but will
     wait till the next merge window before applying them. It's a little more
     complex, and I want to make sure the dynamic code works properly before
     adding more complexity, making it easier to revert if need be.
 
  Minor changes:
 
   - Optimization to user event list traversal.
 
   - Remove intermediate permission of tracefs files (note the intermediate
     permission removes all access to the files so it is not a security concern,
     but just a clean up.)
 
   - Add the complex fix to FORTIFY_SOURCE to the kernel stack event logic.
 
   - Other minor clean ups.
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Merge tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:
 "User visible changes:

   - Added a way to easier filter with cpumasks:

       # echo 'cpumask & CPUS{17-42}' > /sys/kernel/tracing/events/ipi_send_cpumask/filter

   - Show actual size of ring buffer after modifying the ring buffer
     size via buffer_size_kb.

     Currently it just returns what was written, but the actual size
     rounds up to the sub buffer size. Show that real size instead.

  Major changes:

   - Added "eventfs". This is the code that handles the inodes and
     dentries of tracefs/events directory. As there are thousands of
     events, and each event has several inodes and dentries that
     currently exist even when tracing is never used, they take up
     precious memory. Instead, eventfs will allocate the inodes and
     dentries in a JIT way (similar to what procfs does). There is now
     metadata that handles the events and subdirectories, and will
     create the inodes and dentries when they are used.

     Note, I also have patches that remove the subdirectory meta data,
     but will wait till the next merge window before applying them. It's
     a little more complex, and I want to make sure the dynamic code
     works properly before adding more complexity, making it easier to
     revert if need be.

  Minor changes:

   - Optimization to user event list traversal

   - Remove intermediate permission of tracefs files (note the
     intermediate permission removes all access to the files so it is
     not a security concern, but just a clean up)

   - Add the complex fix to FORTIFY_SOURCE to the kernel stack event
     logic

   - Other minor cleanups"

* tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (29 commits)
  tracefs: Remove kerneldoc from struct eventfs_file
  tracefs: Avoid changing i_mode to a temp value
  tracing/user_events: Optimize safe list traversals
  ftrace: Remove empty declaration ftrace_enable_daemon() and ftrace_disable_daemon()
  tracing: Remove unused function declarations
  tracing/filters: Document cpumask filtering
  tracing/filters: Further optimise scalar vs cpumask comparison
  tracing/filters: Optimise CPU vs cpumask filtering when the user mask is a single CPU
  tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU
  tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU
  tracing/filters: Enable filtering the CPU common field by a cpumask
  tracing/filters: Enable filtering a scalar field by a cpumask
  tracing/filters: Enable filtering a cpumask field by another cpumask
  tracing/filters: Dynamically allocate filter_pred.regex
  test: ftrace: Fix kprobe test for eventfs
  eventfs: Move tracing/events to eventfs
  eventfs: Implement removal of meta data from eventfs
  eventfs: Implement functions to create files and dirs when accessed
  eventfs: Implement eventfs lookup, read, open functions
  eventfs: Implement eventfs file add functions
  ...
2023-09-01 16:34:25 -07:00
Linus Torvalds
bd6c11bc43 Networking changes for 6.6.
Core
 ----
 
  - Increase size limits for to-be-sent skb frag allocations. This
    allows tun, tap devices and packet sockets to better cope with large
    writes operations.
 
  - Store netdevs in an xarray, to simplify iterating over netdevs.
 
  - Refactor nexthop selection for multipath routes.
 
  - Improve sched class lifetime handling.
 
  - Add backup nexthop ID support for bridge.
 
  - Implement drop reasons support in openvswitch.
 
  - Several data races annotations and fixes.
 
  - Constify the sk parameter of routing functions.
 
  - Prepend kernel version to netconsole message.
 
 Protocols
 ---------
 
  - Implement support for TCP probing the peer being under memory
    pressure.
 
  - Remove hard coded limitation on IPv6 specific info placement
    inside the socket struct.
 
  - Get rid of sysctl_tcp_adv_win_scale and use an auto-estimated
    per socket scaling factor.
 
  - Scaling-up the IPv6 expired route GC via a separated list of
    expiring routes.
 
  - In-kernel support for the TLS alert protocol.
 
  - Better support for UDP reuseport with connected sockets.
 
  - Add NEXT-C-SID support for SRv6 End.X behavior, reducing the SR
    header size.
 
  - Get rid of additional ancillary per MPTCP connection struct socket.
 
  - Implement support for BPF-based MPTCP packet schedulers.
 
  - Format MPTCP subtests selftests results in TAP.
 
  - Several new SMC 2.1 features including unique experimental options,
    max connections per lgr negotiation, max links per lgr negotiation.
 
 BPF
 ---
 
  - Multi-buffer support in AF_XDP.
 
  - Add multi uprobe BPF links for attaching multiple uprobes
    and usdt probes, which is significantly faster and saves extra fds.
 
  - Implement an fd-based tc BPF attach API (TCX) and BPF link support on
    top of it.
 
  - Add SO_REUSEPORT support for TC bpf_sk_assign.
 
  - Support new instructions from cpu v4 to simplify the generated code and
    feature completeness, for x86, arm64, riscv64.
 
  - Support defragmenting IPv(4|6) packets in BPF.
 
  - Teach verifier actual bounds of bpf_get_smp_processor_id()
    and fix perf+libbpf issue related to custom section handling.
 
  - Introduce bpf map element count and enable it for all program types.
 
  - Add a BPF hook in sys_socket() to change the protocol ID
    from IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy.
 
  - Introduce bpf_me_mcache_free_rcu() and fix OOM under stress.
 
  - Add uprobe support for the bpf_get_func_ip helper.
 
  - Check skb ownership against full socket.
 
  - Support for up to 12 arguments in BPF trampoline.
 
  - Extend link_info for kprobe_multi and perf_event links.
 
 Netfilter
 ---------
 
  - Speed-up process exit by aborting ruleset validation if a
    fatal signal is pending.
 
  - Allow NLA_POLICY_MASK to be used with BE16/BE32 types.
 
 Driver API
 ----------
 
  - Page pool optimizations, to improve data locality and cache usage.
 
  - Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set() to avoid the need
    for raw ioctl() handling in drivers.
 
  - Simplify genetlink dump operations (doit/dumpit) providing them
    the common information already populated in struct genl_info.
 
  - Extend and use the yaml devlink specs to [re]generate the split ops.
 
  - Introduce devlink selective dumps, to allow SF filtering SF based on
    handle and other attributes.
 
  - Add yaml netlink spec for netlink-raw families, allow route, link and
    address related queries via the ynl tool.
 
  - Remove phylink legacy mode support.
 
  - Support offload LED blinking to phy.
 
  - Add devlink port function attributes for IPsec.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - Broadcom ASP 2.0 (72165) ethernet controller
    - MediaTek MT7988 SoC
    - Texas Instruments AM654 SoC
    - Texas Instruments IEP driver
    - Atheros qca8081 phy
    - Marvell 88Q2110 phy
    - NXP TJA1120 phy
 
  - WiFi:
    - MediaTek mt7981 support
 
  - Can:
    - Kvaser SmartFusion2 PCI Express devices
    - Allwinner T113 controllers
    - Texas Instruments tcan4552/4553 chips
 
  - Bluetooth:
    - Intel Gale Peak
    - Qualcomm WCN3988 and WCN7850
    - NXP AW693 and IW624
    - Mediatek MT2925
 
 Drivers
 -------
 
  - Ethernet NICs:
    - nVidia/Mellanox:
      - mlx5:
        - support UDP encapsulation in packet offload mode
        - IPsec packet offload support in eswitch mode
        - improve aRFS observability by adding new set of counters
        - extends MACsec offload support to cover RoCE traffic
        - dynamic completion EQs
      - mlx4:
        - convert to use auxiliary bus instead of custom interface logic
    - Intel
      - ice:
        - implement switchdev bridge offload, even for LAG interfaces
        - implement SRIOV support for LAG interfaces
      - igc:
        - add support for multiple in-flight TX timestamps
    - Broadcom:
      - bnxt:
        - use the unified RX page pool buffers for XDP and non-XDP
        - use the NAPI skb allocation cache
    - OcteonTX2:
      - support Round Robin scheduling HTB offload
      - TC flower offload support for SPI field
    - Freescale:
      -  add XDP_TX feature support
    - AMD:
      - ionic: add support for PCI FLR event
      - sfc:
        - basic conntrack offload
        - introduce eth, ipv4 and ipv6 pedit offloads
    - ST Microelectronics:
      - stmmac: maximze PTP timestamping resolution
 
  - Virtual NICs:
    - Microsoft vNIC:
      - batch ringing RX queue doorbell on receiving packets
      - add page pool for RX buffers
    - Virtio vNIC:
      - add per queue interrupt coalescing support
    - Google vNIC:
      - add queue-page-list mode support
 
  - Ethernet high-speed switches:
    - nVidia/Mellanox (mlxsw):
      - add port range matching tc-flower offload
      - permit enslavement to netdevices with uppers
 
  - Ethernet embedded switches:
    - Marvell (mv88e6xxx):
      - convert to phylink_pcs
    - Renesas:
      - r8A779fx: add speed change support
      - rzn1: enables vlan support
 
  - Ethernet PHYs:
    - convert mv88e6xxx to phylink_pcs
 
  - WiFi:
    - Qualcomm Wi-Fi 7 (ath12k):
      - extremely High Throughput (EHT) PHY support
    - RealTek (rtl8xxxu):
      - enable AP mode for: RTL8192FU, RTL8710BU (RTL8188GU),
        RTL8192EU and RTL8723BU
    - RealTek (rtw89):
      - Introduce Time Averaged SAR (TAS) support
 
  - Connector:
    - support for event filtering
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
 "Core:

   - Increase size limits for to-be-sent skb frag allocations. This
     allows tun, tap devices and packet sockets to better cope with
     large writes operations

   - Store netdevs in an xarray, to simplify iterating over netdevs

   - Refactor nexthop selection for multipath routes

   - Improve sched class lifetime handling

   - Add backup nexthop ID support for bridge

   - Implement drop reasons support in openvswitch

   - Several data races annotations and fixes

   - Constify the sk parameter of routing functions

   - Prepend kernel version to netconsole message

  Protocols:

   - Implement support for TCP probing the peer being under memory
     pressure

   - Remove hard coded limitation on IPv6 specific info placement inside
     the socket struct

   - Get rid of sysctl_tcp_adv_win_scale and use an auto-estimated per
     socket scaling factor

   - Scaling-up the IPv6 expired route GC via a separated list of
     expiring routes

   - In-kernel support for the TLS alert protocol

   - Better support for UDP reuseport with connected sockets

   - Add NEXT-C-SID support for SRv6 End.X behavior, reducing the SR
     header size

   - Get rid of additional ancillary per MPTCP connection struct socket

   - Implement support for BPF-based MPTCP packet schedulers

   - Format MPTCP subtests selftests results in TAP

   - Several new SMC 2.1 features including unique experimental options,
     max connections per lgr negotiation, max links per lgr negotiation

  BPF:

   - Multi-buffer support in AF_XDP

   - Add multi uprobe BPF links for attaching multiple uprobes and usdt
     probes, which is significantly faster and saves extra fds

   - Implement an fd-based tc BPF attach API (TCX) and BPF link support
     on top of it

   - Add SO_REUSEPORT support for TC bpf_sk_assign

   - Support new instructions from cpu v4 to simplify the generated code
     and feature completeness, for x86, arm64, riscv64

   - Support defragmenting IPv(4|6) packets in BPF

   - Teach verifier actual bounds of bpf_get_smp_processor_id() and fix
     perf+libbpf issue related to custom section handling

   - Introduce bpf map element count and enable it for all program types

   - Add a BPF hook in sys_socket() to change the protocol ID from
     IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy

   - Introduce bpf_me_mcache_free_rcu() and fix OOM under stress

   - Add uprobe support for the bpf_get_func_ip helper

   - Check skb ownership against full socket

   - Support for up to 12 arguments in BPF trampoline

   - Extend link_info for kprobe_multi and perf_event links

  Netfilter:

   - Speed-up process exit by aborting ruleset validation if a fatal
     signal is pending

   - Allow NLA_POLICY_MASK to be used with BE16/BE32 types

  Driver API:

   - Page pool optimizations, to improve data locality and cache usage

   - Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set() to avoid the
     need for raw ioctl() handling in drivers

   - Simplify genetlink dump operations (doit/dumpit) providing them the
     common information already populated in struct genl_info

   - Extend and use the yaml devlink specs to [re]generate the split ops

   - Introduce devlink selective dumps, to allow SF filtering SF based
     on handle and other attributes

   - Add yaml netlink spec for netlink-raw families, allow route, link
     and address related queries via the ynl tool

   - Remove phylink legacy mode support

   - Support offload LED blinking to phy

   - Add devlink port function attributes for IPsec

  New hardware / drivers:

   - Ethernet:
      - Broadcom ASP 2.0 (72165) ethernet controller
      - MediaTek MT7988 SoC
      - Texas Instruments AM654 SoC
      - Texas Instruments IEP driver
      - Atheros qca8081 phy
      - Marvell 88Q2110 phy
      - NXP TJA1120 phy

   - WiFi:
      - MediaTek mt7981 support

   - Can:
      - Kvaser SmartFusion2 PCI Express devices
      - Allwinner T113 controllers
      - Texas Instruments tcan4552/4553 chips

   - Bluetooth:
      - Intel Gale Peak
      - Qualcomm WCN3988 and WCN7850
      - NXP AW693 and IW624
      - Mediatek MT2925

  Drivers:

   - Ethernet NICs:
      - nVidia/Mellanox:
         - mlx5:
            - support UDP encapsulation in packet offload mode
            - IPsec packet offload support in eswitch mode
            - improve aRFS observability by adding new set of counters
            - extends MACsec offload support to cover RoCE traffic
            - dynamic completion EQs
         - mlx4:
            - convert to use auxiliary bus instead of custom interface
              logic
      - Intel
         - ice:
            - implement switchdev bridge offload, even for LAG
              interfaces
            - implement SRIOV support for LAG interfaces
         - igc:
            - add support for multiple in-flight TX timestamps
      - Broadcom:
         - bnxt:
            - use the unified RX page pool buffers for XDP and non-XDP
            - use the NAPI skb allocation cache
      - OcteonTX2:
         - support Round Robin scheduling HTB offload
         - TC flower offload support for SPI field
      - Freescale:
         - add XDP_TX feature support
      - AMD:
         - ionic: add support for PCI FLR event
         - sfc:
            - basic conntrack offload
            - introduce eth, ipv4 and ipv6 pedit offloads
      - ST Microelectronics:
         - stmmac: maximze PTP timestamping resolution

   - Virtual NICs:
      - Microsoft vNIC:
         - batch ringing RX queue doorbell on receiving packets
         - add page pool for RX buffers
      - Virtio vNIC:
         - add per queue interrupt coalescing support
      - Google vNIC:
         - add queue-page-list mode support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add port range matching tc-flower offload
         - permit enslavement to netdevices with uppers

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - convert to phylink_pcs
      - Renesas:
         - r8A779fx: add speed change support
         - rzn1: enables vlan support

   - Ethernet PHYs:
      - convert mv88e6xxx to phylink_pcs

   - WiFi:
      - Qualcomm Wi-Fi 7 (ath12k):
         - extremely High Throughput (EHT) PHY support
      - RealTek (rtl8xxxu):
         - enable AP mode for: RTL8192FU, RTL8710BU (RTL8188GU),
           RTL8192EU and RTL8723BU
      - RealTek (rtw89):
         - Introduce Time Averaged SAR (TAS) support

   - Connector:
      - support for event filtering"

* tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1806 commits)
  net: ethernet: mtk_wed: minor change in wed_{tx,rx}info_show
  net: ethernet: mtk_wed: add some more info in wed_txinfo_show handler
  net: stmmac: clarify difference between "interface" and "phy_interface"
  r8152: add vendor/device ID pair for D-Link DUB-E250
  devlink: move devlink_notify_register/unregister() to dev.c
  devlink: move small_ops definition into netlink.c
  devlink: move tracepoint definitions into core.c
  devlink: push linecard related code into separate file
  devlink: push rate related code into separate file
  devlink: push trap related code into separate file
  devlink: use tracepoint_enabled() helper
  devlink: push region related code into separate file
  devlink: push param related code into separate file
  devlink: push resource related code into separate file
  devlink: push dpipe related code into separate file
  devlink: move and rename devlink_dpipe_send_and_alloc_skb() helper
  devlink: push shared buffer related code into separate file
  devlink: push port related code into separate file
  devlink: push object register/unregister notifications into separate helpers
  inet: fix IP_TRANSPARENT error handling
  ...
2023-08-29 11:33:01 -07:00
Masami Hiramatsu (Google)
08c9306fc2 tracing/fprobe-event: Assume fprobe is a return event by $retval
Assume the fprobe event is a return event if there is $retval is
used in the probe's argument without %return. e.g.

echo 'f:myevent vfs_read $retval' >> dynamic_events

then 'myevent' is a return probe event.

Link: https://lore.kernel.org/all/169272160261.160970.13613040161560998787.stgit@devnote2/

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:41:32 +09:00
Masami Hiramatsu (Google)
27973e5c64 tracing/probes: Add string type check with BTF
Add a string type checking with BTF information if possible.
This will check whether the given BTF argument (and field) is
signed char array or pointer to signed char. If not, it reject
the 'string' type. If it is pointer to signed char, it adds
a dereference opration so that it can correctly fetch the
string data from memory.

 # echo 'f getname_flags%return retval->name:string' >> dynamic_events
 # echo 't sched_switch next->comm:string' >> dynamic_events

The above cases, 'struct filename::name' is 'char *' and
'struct task_struct::comm' is 'char []'. But in both case,
user can specify ':string' to fetch the string data.

Link: https://lore.kernel.org/all/169272159250.160970.1881112937198526188.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:41:13 +09:00
Masami Hiramatsu (Google)
d157d76944 tracing/probes: Support BTF field access from $retval
Support BTF argument on '$retval' for function return events including
kretprobe and fprobe for accessing the return value.
This also allows user to access its fields if the return value is a
pointer of a data structure.

E.g.
 # echo 'f getname_flags%return +0($retval->name):string' \
   > dynamic_events
 # echo 1 > events/fprobes/getname_flags__exit/enable
 # ls > /dev/null
 # head -n 40 trace | tail
              ls-87      [000] ...1.  8067.616101: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./function_profile_enabled"
              ls-87      [000] ...1.  8067.616108: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./trace_stat"
              ls-87      [000] ...1.  8067.616115: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./set_graph_notrace"
              ls-87      [000] ...1.  8067.616122: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./set_graph_function"
              ls-87      [000] ...1.  8067.616129: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./set_ftrace_notrace"
              ls-87      [000] ...1.  8067.616135: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./set_ftrace_filter"
              ls-87      [000] ...1.  8067.616143: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./touched_functions"
              ls-87      [000] ...1.  8067.616237: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./enabled_functions"
              ls-87      [000] ...1.  8067.616245: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./available_filter_functions"
              ls-87      [000] ...1.  8067.616253: getname_flags__exit: (vfs_fstatat+0x3c/0x70 <- getname_flags) arg1="./set_ftrace_notrace_pid"


Link: https://lore.kernel.org/all/169272158234.160970.2446691104240645205.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:40:51 +09:00
Masami Hiramatsu (Google)
c440adfbe3 tracing/probes: Support BTF based data structure field access
Using BTF to access the fields of a data structure. You can use this
for accessing the field with '->' or '.' operation with BTF argument.

 # echo 't sched_switch next=next->pid vruntime=next->se.vruntime' \
   > dynamic_events
 # echo 1 > events/tracepoints/sched_switch/enable
 # head -n 40 trace | tail
          <idle>-0       [000] d..3.   272.565382: sched_switch: (__probestub_sched_switch+0x4/0x10) next=26 vruntime=956533179
      kcompactd0-26      [000] d..3.   272.565406: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
          <idle>-0       [000] d..3.   273.069441: sched_switch: (__probestub_sched_switch+0x4/0x10) next=9 vruntime=956533179
     kworker/0:1-9       [000] d..3.   273.069464: sched_switch: (__probestub_sched_switch+0x4/0x10) next=26 vruntime=956579181
      kcompactd0-26      [000] d..3.   273.069480: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
          <idle>-0       [000] d..3.   273.141434: sched_switch: (__probestub_sched_switch+0x4/0x10) next=22 vruntime=956533179
    kworker/u2:1-22      [000] d..3.   273.141461: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
          <idle>-0       [000] d..3.   273.480872: sched_switch: (__probestub_sched_switch+0x4/0x10) next=22 vruntime=956585857
    kworker/u2:1-22      [000] d..3.   273.480905: sched_switch: (__probestub_sched_switch+0x4/0x10) next=70 vruntime=959533179
              sh-70      [000] d..3.   273.481102: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0

Link: https://lore.kernel.org/all/169272157251.160970.9318175874130965571.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:40:28 +09:00
Masami Hiramatsu (Google)
302db0f5b3 tracing/probes: Add a function to search a member of a struct/union
Add btf_find_struct_member() API to search a member of a given data structure
or union from the member's name.

Link: https://lore.kernel.org/all/169272156248.160970.8868479822371129043.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:40:16 +09:00
Masami Hiramatsu (Google)
ebeed8d4a5 tracing/probes: Move finding func-proto API and getting func-param API to trace_btf
Move generic function-proto find API and getting function parameter API
to BTF library code from trace_probe.c. This will avoid redundant efforts
on different feature.

Link: https://lore.kernel.org/all/169272155255.160970.719426926348706349.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:39:45 +09:00
Masami Hiramatsu (Google)
b1d1e90490 tracing/probes: Support BTF argument on module functions
Since the btf returned from bpf_get_btf_vmlinux() only covers functions in
the vmlinux, BTF argument is not available on the functions in the modules.
Use bpf_find_btf_id() instead of bpf_get_btf_vmlinux()+btf_find_name_kind()
so that BTF argument can find the correct struct btf and btf_type in it.
With this fix, fprobe events can use `$arg*` on module functions as below

 # grep nf_log_ip_packet /proc/kallsyms
ffffffffa0005c00 t nf_log_ip_packet	[nf_log_syslog]
ffffffffa0005bf0 t __pfx_nf_log_ip_packet	[nf_log_syslog]
 # echo 'f nf_log_ip_packet $arg*' > dynamic_events
 # cat dynamic_events
f:fprobes/nf_log_ip_packet__entry nf_log_ip_packet net=net pf=pf hooknum=hooknum skb=skb in=in out=out loginfo=loginfo prefix=prefix

To support the module's btf which is removable, the struct btf needs to be
ref-counted. So this also records the btf in the traceprobe_parse_context
and returns the refcount when the parse has done.

Link: https://lore.kernel.org/all/169272154223.160970.3507930084247934031.stgit@devnote2/

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-23 09:39:15 +09:00
Chuang Wang
f8bbf8b990 tracing/eprobe: Iterate trace_eprobe directly
Refer to the description in [1], we can skip "container_of()" following
"list_for_each_entry()" by using "list_for_each_entry()" with
"struct trace_eprobe" and "tp.list".

Also, this patch defines "for_each_trace_eprobe_tp" to simplify the code
of the same logic.

[1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/

Link: https://lore.kernel.org/all/20230822022433.262478-1-nashuiliang@gmail.com/

Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-08-23 09:38:56 +09:00
Eric Vaughn
a943188dab tracing/user_events: Optimize safe list traversals
Several of the list traversals in the user_events facility use safe list
traversals where they could be using the unsafe versions instead.

Replace these safe traversals with their unsafe counterparts in the
interest of optimization.

Link: https://lore.kernel.org/linux-trace-kernel/20230810194337.695983-1-ervaughn@linux.microsoft.com

Suggested-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Eric Vaughn <ervaughn@linux.microsoft.com>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-22 05:22:10 -04:00
Yue Haibing
efde97a175 tracing: Remove unused function declarations
Commit 9457158bbc ("tracing: Fix reset of time stamps during trace_clock changes")
left behind tracing_reset_current() declaration.
Also commit 6954e41526 ("tracing: Place trace_pid_list logic into abstract functions")
removed trace_free_pid_list() implementation but leave declaration.

Link: https://lore.kernel.org/linux-trace-kernel/20230803144028.25492-1-yuehaibing@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-22 05:19:35 -04:00
Valentin Schneider
38c6f68083 tracing/filters: Further optimise scalar vs cpumask comparison
Per the previous commits, we now only enter do_filter_scalar_cpumask() with
a mask of weight greater than one. Optimise the equality checks.

Link: https://lkml.kernel.org/r/20230707172155.70873-9-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-22 05:13:29 -04:00
Valentin Schneider
1cffbe6c62 tracing/filters: Optimise CPU vs cpumask filtering when the user mask is a single CPU
Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.

In this case we can directly re-use filter_pred_cpu(), we just need to
transform '&' into '==' before executing it.

Link: https://lkml.kernel.org/r/20230707172155.70873-8-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-22 05:13:29 -04:00
Valentin Schneider
ca77dd8ce4 tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU
Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.

When the mask contains a single CPU, directly re-use the unsigned field
predicate functions. Transform '&' into '==' beforehand.

Link: https://lkml.kernel.org/r/20230707172155.70873-7-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-22 05:13:29 -04:00