30 Oct, 2020
1 commit
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There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arraysSigned-off-by: Gustavo A. R. Silva
03 Oct, 2020
1 commit
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Naresh reported a bug that appears to be a side effect of the static
calls. It happens when going from more than one tracepoint callback to
a single one, and removing the first callback on the list. The list of
tracepoint callbacks holds data and a function to call with the
parameters of that tracepoint and a handler to the associated data.old_list:
0: func = foo; data = NULL;
1: func = bar; data = &bar_struct;new_list:
0: func = bar; data = &bar_struct;CPU 0 CPU 1
----- -----
tp_funcs = old_list;
tp_static_caller = tp_interator__DO_TRACE()
data = tp_funcs[0].data = NULL;
tp_funcs = new_list;
tracepoint_update_call()
tp_static_caller = tp_funcs[0] = bar;
tp_static_caller(data)
bar(data)
x = data->item = NULL->itemBOOM!
To solve this, add a tracepoint_synchronize_unregister() between
changing tp_funcs and updating the static tracepoint, that does both a
synchronize_rcu() and synchronize_srcu(). This will ensure that when
the static call is updated to the single callback that it will be
receiving the data that it registered with.Fixes: d25e37d89dd2f ("tracepoint: Optimize using static_call()")
Reported-by: Naresh Kamboju
Signed-off-by: Steven Rostedt (VMware)
Signed-off-by: Peter Zijlstra (Intel)
Link: https://lore.kernel.org/linux-next/CA+G9fYvPXVRO0NV7yL=FxCmFEMYkCwdz7R=9W+_votpT824YJA@mail.gmail.com
01 Sep, 2020
2 commits
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Currently the tracepoint site will iterate a vector and issue indirect
calls to however many handlers are registered (ie. the vector is
long).Using static_call() it is possible to optimize this for the common
case of only having a single handler registered. In this case the
static_call() can directly call this handler. Otherwise, if the vector
is longer than 1, call a function that iterates the whole vector like
the current code.[peterz: updated to new interface]
Signed-off-by: Steven Rostedt (VMware)
Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Ingo Molnar
Cc: Linus Torvalds
Link: https://lore.kernel.org/r/20200818135805.279421092@infradead.org -
While auditing all module notifiers I noticed a whole bunch of fail
wrt the return value. Notifiers have a 'special' return semantics.As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but
notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a
comment that says "Don't care".From this I've used NOTIFY_DONE when the function completely ignores
the callback and notifier_to_error() isn't used.Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Ingo Molnar
Reviewed-by: Mathieu Desnoyers
Reviewed-by: Joel Fernandes (Google)
Reviewed-by: Robert Richter
Acked-by: Steven Rostedt (VMware)
Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org
19 Jul, 2019
1 commit
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Pull tracing updates from Steven Rostedt:
"The main changes in this release include:- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes"
* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
tracing: Make trace_get_fields() global
tracing: Let filter_assign_type() detect FILTER_PTR_STRING
tracing: Pass type into tracing_generic_entry_update()
ftrace/selftest: Test if set_event/ftrace_pid exists before writing
ftrace/selftests: Return the skip code when tracing directory not configured in kernel
tracing/kprobe: Check registered state using kprobe
tracing/probe: Add trace_event_call accesses APIs
tracing/probe: Add probe event name and group name accesses APIs
tracing/probe: Add trace flag access APIs for trace_probe
tracing/probe: Add trace_event_file access APIs for trace_probe
tracing/probe: Add trace_event_call register API for trace_probe
tracing/probe: Add trace_probe init and free functions
tracing/uprobe: Set print format when parsing command
tracing/kprobe: Set print format right after parsed command
kprobes: Fix to init kprobes in subsys_initcall
tracepoint: Use struct_size() in kmalloc()
ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
ftrace: Enable trampoline when rec count returns back to one
tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
tracing: Make a separate config for trace event self tests
...
18 Jun, 2019
1 commit
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One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:struct tp_probes {
...
struct tracepoint_func probes[0];
};instance = kmalloc(sizeof(sizeof(struct tp_probes) +
sizeof(struct tracepoint_func) * count, GFP_KERNEL);Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:instance = kmalloc(struct_size(instance, probes, count) GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva
Signed-off-by: Steven Rostedt (VMware)
31 May, 2019
1 commit
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Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usaextracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Allison Randal
Reviewed-by: Richard Fontana
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman
28 Nov, 2018
1 commit
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Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can
be replaced by synchronize_rcu(). Similarly, call_rcu_sched() can be
replaced by call_rcu(). This commit therefore makes these changes.Signed-off-by: Paul E. McKenney
Cc: Ingo Molnar
Cc:
Acked-by: Steven Rostedt (VMware)
18 Oct, 2018
1 commit
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commit 46e0c9be206f ("kernel: tracepoints: add support for relative
references") changes the layout of the __tracepoint_ptrs section on
architectures supporting relative references. However, it does so
without turning struct tracepoint * const into const int elsewhere in
the tracepoint code, which has the following side-effect:Setting mod->num_tracepoints is done in by module.c:
mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
sizeof(*mod->tracepoints_ptrs),
&mod->num_tracepoints);Basically, since sizeof(*mod->tracepoints_ptrs) is a pointer size
(rather than sizeof(int)), num_tracepoints is erroneously set to half the
size it should be on 64-bit arch. So a module with an odd number of
tracepoints misses the last tracepoint due to effect of integer
division.So in the module going notifier:
for_each_tracepoint_range(mod->tracepoints_ptrs,
mod->tracepoints_ptrs + mod->num_tracepoints,
tp_module_going_check_quiescent, NULL);the expression (mod->tracepoints_ptrs + mod->num_tracepoints) actually
evaluates to something within the bounds of the array, but miss the
last tracepoint if the number of tracepoints is odd on 64-bit arch.Fix this by introducing a new typedef: tracepoint_ptr_t, which
is either "const int" on architectures that have PREL32 relocations,
or "struct tracepoint * const" on architectures that does not have
this feature.Also provide a new tracepoint_ptr_defer() static inline to
encapsulate deferencing this type rather than duplicate code and
ugly idefs within the for_each_tracepoint_range() implementation.This issue appears in 4.19-rc kernels, and should ideally be fixed
before the end of the rc cycle.Acked-by: Ard Biesheuvel
Acked-by: Jessica Yu
Link: http://lkml.kernel.org/r/20181013191050.22389-1-mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org
Cc: Michael Ellerman
Cc: Ingo Molnar
Cc: Ard Biesheuvel
Cc: Arnd Bergmann
Cc: Benjamin Herrenschmidt
Cc: Bjorn Helgaas
Cc: Catalin Marinas
Cc: James Morris
Cc: James Morris
Cc: Josh Poimboeuf
Cc: Kees Cook
Cc: Nicolas Pitre
Cc: Paul Mackerras
Cc: Petr Mladek
Cc: Russell King
Cc: "Serge E. Hallyn"
Cc: Sergey Senozhatsky
Cc: Thomas Garnier
Cc: Thomas Gleixner
Cc: Will Deacon
Cc: Andrew Morton
Cc: Linus Torvalds
Cc: Greg Kroah-Hartman
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt (VMware)
23 Aug, 2018
1 commit
-
To avoid the need for relocating absolute references to tracepoint
structures at boot time when running relocatable kernels (which may
take a disproportionate amount of space), add the option to emit
these tables as relative references instead.Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org
Acked-by: Michael Ellerman
Acked-by: Ingo Molnar
Acked-by: Steven Rostedt (VMware)
Signed-off-by: Ard Biesheuvel
Cc: Arnd Bergmann
Cc: Benjamin Herrenschmidt
Cc: Bjorn Helgaas
Cc: Catalin Marinas
Cc: James Morris
Cc: James Morris
Cc: Jessica Yu
Cc: Josh Poimboeuf
Cc: Kees Cook
Cc: Nicolas Pitre
Cc: Paul Mackerras
Cc: Petr Mladek
Cc: Russell King
Cc: "Serge E. Hallyn"
Cc: Sergey Senozhatsky
Cc: Thomas Garnier
Cc: Thomas Gleixner
Cc: Will Deacon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Aug, 2018
1 commit
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When enabling trace events via the kernel command line, I hit this warning:
WARNING: CPU: 0 PID: 13 at kernel/rcu/srcutree.c:236 check_init_srcu_struct+0xe/0x61
Modules linked in:
CPU: 0 PID: 13 Comm: watchdog/0 Not tainted 4.18.0-rc6-test+ #6
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
RIP: 0010:check_init_srcu_struct+0xe/0x61
Code: 48 c7 c6 ec 8a 65 b4 e8 ff 79 fe ff 48 89 df 31 f6 e8 f2 fa ff ff 5a
5b 41 5c 5d c3 0f 1f 44 00 00 83 3d 68 94 b8 01 01 75 02 0b 48 8b 87 f0
0a 00 00 a8 03 74 45 55 48 89 e5 41 55 41 54 4c
RSP: 0000:ffff96eb9ea03e68 EFLAGS: 00010246
RAX: ffff96eb962b5b01 RBX: ffffffffb4a87420 RCX: 0000000000000001
RDX: ffffffffb3107969 RSI: ffff96eb962b5b40 RDI: ffffffffb4a87420
RBP: ffff96eb9ea03eb0 R08: ffffabbd00cd7f48 R09: 0000000000000000
R10: ffff96eb9ea03e68 R11: ffffffffb4a6eec0 R12: ffff96eb962b5b40
R13: ffff96eb9ea03ef8 R14: ffffffffb3107969 R15: ffffffffb3107948
FS: 0000000000000000(0000) GS:ffff96eb9ea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff96eb13ab2000 CR3: 0000000192a1e001 CR4: 00000000001606f0
Call Trace:
? __call_srcu+0x2d/0x290
? rcu_process_callbacks+0x26e/0x448
? allocate_probes+0x2b/0x2b
call_srcu+0x13/0x15
rcu_free_old_probes+0x1f/0x21
rcu_process_callbacks+0x2ed/0x448
__do_softirq+0x172/0x336
irq_exit+0x62/0xb2
smp_apic_timer_interrupt+0x161/0x19e
apic_timer_interrupt+0xf/0x20
The problem is that the enabling of trace events before RCU is set up will
cause SRCU to give this warning. To avoid this, add a list to store probes
that need to be freed till after RCU is initialized, and then free them
then.Link: http://lkml.kernel.org/r/20180810113554.1df28050@gandalf.local.home
Link: http://lkml.kernel.org/r/20180810123517.5e9714ad@gandalf.local.homeAcked-by: Paul E. McKenney
Reviewed-by: Joel Fernandes (Google)
Fixes: e6753f23d961d ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Signed-off-by: Steven Rostedt (VMware)
31 Jul, 2018
1 commit
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In recent tests with IRQ on/off tracepoints, a large performance
overhead ~10% is noticed when running hackbench. This is root caused to
calls to rcu_irq_enter_irqson and rcu_irq_exit_irqson from the
tracepoint code. Following a long discussion on the list [1] about this,
we concluded that srcu is a better alternative for use during rcu idle.
Although it does involve extra barriers, its lighter than the sched-rcu
version which has to do additional RCU calls to notify RCU idle about
entry into RCU sections.In this patch, we change the underlying implementation of the
trace_*_rcuidle API to use SRCU. This has shown to improve performance
alot for the high frequency irq enable/disable tracepoints.Test: Tested idle and preempt/irq tracepoints.
Here are some performance numbers:
With a run of the following 30 times on a single core x86 Qemu instance
with 1GB memory:
hackbench -g 4 -f 2 -l 3000Completion times in seconds. CONFIG_PROVE_LOCKING=y.
No patches (without this series)
Mean: 3.048
Median: 3.025
Std Dev: 0.064With Lockdep using irq tracepoints with RCU implementation:
Mean: 3.451 (-11.66 %)
Median: 3.447 (-12.22%)
Std Dev: 0.049With Lockdep using irq tracepoints with SRCU implementation (this series):
Mean: 3.020 (I would consider the improvement against the "without
this series" case as just noise).
Median: 3.013
Std Dev: 0.033[1] https://patchwork.kernel.org/patch/10344297/
[remove rcu_read_lock_sched_notrace as its the equivalent of
preempt_disable_notrace and is unnecessary to call in tracepoint code]
Link: http://lkml.kernel.org/r/20180730222423.196630-3-joel@joelfernandes.orgCleaned-up-by: Peter Zijlstra
Acked-by: Peter Zijlstra
Reviewed-by: Mathieu Desnoyers
Signed-off-by: Joel Fernandes (Google)
[ Simplified WARN_ON_ONCE() ]
Signed-off-by: Steven Rostedt (VMware)
29 May, 2018
1 commit
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The description of tracepoint_probe_register duplicates
with tracepoint_probe_register_prio. This patch cleans up
the descriptions.Link: http://lkml.kernel.org/r/20170616082643.7311-1-jlee@suse.com
Signed-off-by: "Lee, Chun-Yi"
Signed-off-by: Steven Rostedt (VMware)
01 May, 2018
1 commit
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Tracepoint should only warn when a kernel API user does not respect the
required preconditions (e.g. same tracepoint enabled twice, or called
to remove a tracepoint that does not exist).Silence warning in out-of-memory conditions, given that the error is
returned to the caller.This ensures that out-of-memory error-injection testing does not trigger
warnings in tracepoint.c, which were seen by syzbot.Link: https://lkml.kernel.org/r/001a114465e241a8720567419a72@google.com
Link: https://lkml.kernel.org/r/001a1140e0de15fc910567464190@google.com
Link: http://lkml.kernel.org/r/20180315124424.32319-1-mathieu.desnoyers@efficios.comCC: Peter Zijlstra
CC: Jiri Olsa
CC: Arnaldo Carvalho de Melo
CC: Alexander Shishkin
CC: Namhyung Kim
CC: stable@vger.kernel.org
Fixes: de7b2973903c6 ("tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints")
Reported-by: syzbot+9c0d616860575a73166a@syzkaller.appspotmail.com
Reported-by: syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt (VMware)
05 Dec, 2017
1 commit
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The comment in tracepoint_add_func() mentions smp_read_barrier_depends(),
whose use should be quite restricted. This commit updates the comment
to instead mention the smp_store_release() and rcu_dereference_sched()
that the current code actually uses.Signed-off-by: Paul E. McKenney
Cc: Ingo Molnar
Acked-by: Steven Rostedt (VMware)
Acked-by: Mathieu Desnoyers
02 Mar, 2017
2 commits
-
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
09 Dec, 2016
1 commit
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Some tracepoints have a registration function that gets enabled when the
tracepoint is enabled. There may be cases that the registraction function
must fail (for example, can't allocate enough memory). In this case, the
tracepoint should also fail to register, otherwise the user would not know
why the tracepoint is not working.Cc: David Howells
Cc: Seiji Aguchi
Cc: Anton Blanchard
Cc: Mathieu Desnoyers
Signed-off-by: Steven Rostedt
23 Mar, 2016
1 commit
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Use the more common logging method with the eventual goal of removing
pr_warning altogether.Miscellanea:
- Realign arguments
- Coalesce formats
- Add missing space between a few coalesced formatsSigned-off-by: Joe Perches
Acked-by: Rafael J. Wysocki [kernel/power/suspend.c]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Oct, 2015
1 commit
-
In order to guarantee that a probe will be called before other probes that
are attached to a tracepoint, there needs to be a mechanism to provide
priority of one probe over the others.Adding a prio field to the struct tracepoint_func, which lets the probes be
sorted by the priority set in the structure. If no priority is specified,
then a priority of 10 is given (this is a macro, and perhaps may be changed
in the future).Now probes may be added to affect other probes that are attached to a
tracepoint with a guaranteed order.One use case would be to allow tracing of tracepoints be able to filter by
pid. A special (higher priority probe) may be added to the sched_switch
tracepoint and set the necessary flags of the other tracepoints to notify
them if they should be traced or not. In case a tracepoint is enabled at the
sched_switch tracepoint too, the order of the two are not random.Cc: Mathieu Desnoyers
Signed-off-by: Steven Rostedt
21 Jun, 2014
2 commits
-
syscall_regfunc() ignores the kernel threads because "it has no effect",
see cc3b13c1 "Don't trace kernel thread syscalls" which added this check.However, this means that a user-space task spawned by call_usermodehelper()
will run without TIF_SYSCALL_TRACEPOINT if sys_tracepoint_refcount != 0.Remove this check. The unnecessary report from ret_from_fork path mentioned
by cc3b13c1 is no longer possible, see See commit fb45550d76bb5 "make sure
that kernel_thread() callbacks call do_exit() themselves".A kernel_thread() callback can only return and take the int_ret_from_sys_call
path after do_execve() succeeds, otherwise the kernel will crash. But in this
case it is no longer a kernel thread and thus is needs TIF_SYSCALL_TRACEPOINT.Link: http://lkml.kernel.org/p/20140413185938.GD20668@redhat.com
Signed-off-by: Oleg Nesterov
Signed-off-by: Steven Rostedt -
1. Remove _irqsafe from syscall_regfunc/syscall_unregfunc,
read_lock(tasklist) doesn't need to disable irqs.2. Change this code to avoid the deprecated do_each_thread()
and use for_each_process_thread() (stolen from the patch
from Frederic).3. Change syscall_regfunc() to check PF_KTHREAD to skip
the kernel threads, ->mm != NULL is the common mistake.Note: probably this check should be simply removed, needs
another patch.[fweisbec@gmail.com: s/do_each_thread/for_each_process_thread/]
Link: http://lkml.kernel.org/p/20140413185918.GC20668@redhat.comSigned-off-by: Oleg Nesterov
Signed-off-by: Steven Rostedt
05 Jun, 2014
1 commit
-
Signed-off-by: Fabian Frederick
Cc: Steven Rostedt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2014
1 commit
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Commit de7b2973903c "tracepoint: Use struct pointer instead of name hash
for reg/unreg tracepoints" introduces a use after free by calling
release_probes on the old struct tracepoint array before the newly
allocated array is published with rcu_assign_pointer. There is a race
window where tracepoints (RCU readers) can perform a
"use-after-grace-period-after-free", which shows up as a GPF in
stress-tests.Link: http://lkml.kernel.org/r/53698021.5020108@oracle.com
Link: http://lkml.kernel.org/p/1399549669-25465-1-git-send-email-mathieu.desnoyers@efficios.comReported-by: Sasha Levin
CC: Oleg Nesterov
CC: Dave Jones
Fixes: de7b2973903c "tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints"
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt
13 Apr, 2014
1 commit
-
Pull more tracing updates from Steven Rostedt:
"This includes the final patch to clean up and fix the issue with the
design of tracepoints and how a user could register a tracepoint and
have that tracepoint not be activated but no error was shown.The design was for an out of tree module but broke in tree users. The
clean up was to remove the saving of the hash table of tracepoint
names such that they can be enabled before they exist (enabling a
module tracepoint before that module is loaded). This added more
complexity than needed. The clean up was to remove that code and just
enable tracepoints that exist or fail if they do not.This removed a lot of code as well as the complexity that it brought.
As a side effect, instead of registering a tracepoint by its name, the
tracepoint needs to be registered with the tracepoint descriptor.
This removes having to duplicate the tracepoint names that are
enabled.The second patch was added that simplified the way modules were
searched for.This cleanup required changes that were in the 3.15 queue as well as
some changes that were added late in the 3.14-rc cycle. This final
change waited till the two were merged in upstream and then the change
was added and full tests were run. Unfortunately, the test found some
errors, but after it was already submitted to the for-next branch and
not to be rebased. Sparse errors were detected by Fengguang Wu's bot
tests, and my internal tests discovered that the anonymous union
initialization triggered a bug in older gcc compilers. Luckily, there
was a bugzilla for the gcc bug which gave a work around to the
problem. The third and fourth patch handled the sparse error and the
gcc bug respectively.A final patch was tagged along to fix a missing documentation for the
README file"* tag 'trace-3.15-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Add missing function triggers dump and cpudump to README
tracing: Fix anonymous unions in struct ftrace_event_call
tracepoint: Fix sparse warnings in tracepoint.c
tracepoint: Simplify tracepoint module search
tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints
09 Apr, 2014
3 commits
-
Fix the following sparse warnings:
CHECK kernel/tracepoint.c
kernel/tracepoint.c:184:18: warning: incorrect type in assignment (different address spaces)
kernel/tracepoint.c:184:18: expected struct tracepoint_func *tp_funcs
kernel/tracepoint.c:184:18: got struct tracepoint_func [noderef] *funcs
kernel/tracepoint.c:216:18: warning: incorrect type in assignment (different address spaces)
kernel/tracepoint.c:216:18: expected struct tracepoint_func *tp_funcs
kernel/tracepoint.c:216:18: got struct tracepoint_func [noderef] *funcs
kernel/tracepoint.c:392:24: error: return expression in void function
CC kernel/tracepoint.o
kernel/tracepoint.c: In function tracepoint_module_going:
kernel/tracepoint.c:491:6: warning: symbol 'syscall_regfunc' was not declared. Should it be static?
kernel/tracepoint.c:508:6: warning: symbol 'syscall_unregfunc' was not declared. Should it be static?Link: http://lkml.kernel.org/r/1397049883-28692-1-git-send-email-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt -
Instead of copying the num_tracepoints and tracepoints_ptrs from
the module structure to the tp_mod structure, which only uses it to
find the module associated to tracepoints of modules that are coming
and going, simply copy the pointer to the module struct to the tracepoint
tp_module structure.Also removed un-needed brackets around an if statement.
Link: http://lkml.kernel.org/r/20140408201705.4dad2c4a@gandalf.local.home
Acked-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt -
Register/unregister tracepoint probes with struct tracepoint pointer
rather than tracepoint name.This change, which vastly simplifies tracepoint.c, has been proposed by
Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux
size.From this point on, the tracers need to pass a struct tracepoint pointer
to probe register/unregister. A probe can now only be connected to a
tracepoint that exists. Moreover, tracers are responsible for
unregistering the probe before the module containing its associated
tracepoint is unloaded.text data bss dec hex filename
10443444 4282528 10391552 25117524 17f4354 vmlinux.orig
10434930 4282848 10391552 25109330 17f2352 vmlinuxLink: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com
CC: Ingo Molnar
CC: Frederic Weisbecker
CC: Andrew Morton
CC: Frank Ch. Eigler
CC: Johannes Berg
Signed-off-by: Mathieu Desnoyers
[ SDR - fixed return val in void func in tracepoint_module_going() ]
Signed-off-by: Steven Rostedt
07 Apr, 2014
1 commit
-
Pull module updates from Rusty Russell:
"Nothing major: the stricter permissions checking for sysfs broke a
staging driver; fix included. Greg KH said he'd take the patch but
hadn't as the merge window opened, so it's included here to avoid
breaking build"* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
staging: fix up speakup kobject mode
Use 'E' instead of 'X' for unsigned module taint flag.
VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.
kallsyms: fix percpu vars on x86-64 with relocation.
kallsyms: generalize address range checking
module: LLVMLinux: Remove unused function warning from __param_check macro
Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE
module: remove MODULE_GENERIC_TABLE
module: allow multiple calls to MODULE_DEVICE_TABLE() per module
module: use pr_cont
04 Apr, 2014
1 commit
-
Pull tracing updates from Steven Rostedt:
"Most of the changes were largely clean ups, and some documentation.
But there were a few features that were added:Uprobes now work with event triggers and multi buffers and have
support under ftrace and perf.The big feature is that the function tracer can now be used within the
multi buffer instances. That is, you can now trace some functions in
one buffer, others in another buffer, all functions in a third buffer
and so on. They are basically agnostic from each other. This only
works for the function tracer and not for the function graph trace,
although you can have the function graph tracer running in the top
level buffer (or any tracer for that matter) and have different
function tracing going on in the sub buffers"* tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
tracing: Add BUG_ON when stack end location is over written
tracepoint: Remove unused API functions
Revert "tracing: Move event storage for array from macro to standalone function"
ftrace: Constify ftrace_text_reserved
tracepoints: API doc update to tracepoint_probe_register() return value
tracepoints: API doc update to data argument
ftrace: Fix compilation warning about control_ops_free
ftrace/x86: BUG when ftrace recovery fails
ftrace: Warn on error when modifying ftrace function
ftrace: Remove freelist from struct dyn_ftrace
ftrace: Do not pass data to ftrace_dyn_arch_init
ftrace: Pass retval through return in ftrace_dyn_arch_init()
ftrace: Inline the code from ftrace_dyn_table_alloc()
ftrace: Cleanup of global variables ftrace_new_pgs and ftrace_update_cnt
tracing: Evaluate len expression only once in __dynamic_array macro
tracing: Correctly expand len expressions from __dynamic_array macro
tracing/module: Replace include of tracepoint.h with jump_label.h in module.h
tracing: Fix event header migrate.h to include tracepoint.h
tracing: Fix event header writeback.h to include tracepoint.h
tracing: Warn if a tracepoint is not set via debugfs
...
22 Mar, 2014
1 commit
-
After the following commit:
commit b75ef8b44b1cb95f5a26484b0e2fe37a63b12b44
Author: Mathieu Desnoyers
Date: Wed Aug 10 15:18:39 2011 -0400Tracepoint: Dissociate from module mutex
The following functions became unnecessary:
- tracepoint_probe_register_noupdate,
- tracepoint_probe_unregister_noupdate,
- tracepoint_probe_update_all.In fact, none of the in-kernel tracers, nor LTTng, nor SystemTAP use
them. Remove those.Moreover, the functions:
- tracepoint_iter_start,
- tracepoint_iter_next,
- tracepoint_iter_stop,
- tracepoint_iter_reset.are unused by in-kernel tracers, LTTng and SystemTAP. Remove those too.
Link: http://lkml.kernel.org/r/1395379142-2118-2-git-send-email-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt
13 Mar, 2014
1 commit
-
Users have reported being unable to trace non-signed modules loaded
within a kernel supporting module signature.This is caused by tracepoint.c:tracepoint_module_coming() refusing to
take into account tracepoints sitting within force-loaded modules
(TAINT_FORCED_MODULE). The reason for this check, in the first place, is
that a force-loaded module may have a struct module incompatible with
the layout expected by the kernel, and can thus cause a kernel crash
upon forced load of that module on a kernel with CONFIG_TRACEPOINTS=y.Tracepoints, however, specifically accept TAINT_OOT_MODULE and
TAINT_CRAP, since those modules do not lead to the "very likely system
crash" issue cited above for force-loaded modules.With kernels having CONFIG_MODULE_SIG=y (signed modules), a non-signed
module is tainted re-using the TAINT_FORCED_MODULE taint flag.
Unfortunately, this means that Tracepoints treat that module as a
force-loaded module, and thus silently refuse to consider any tracepoint
within this module.Since an unsigned module does not fit within the "very likely system
crash" category of tainting, add a new TAINT_UNSIGNED_MODULE taint flag
to specifically address this taint behavior, and accept those modules
within Tracepoints. We use the letter 'X' as a taint flag character for
a module being loaded that doesn't know how to sign its name (proposed
by Steven Rostedt).Also add the missing 'O' entry to trace event show_module_flags() list
for the sake of completeness.Signed-off-by: Mathieu Desnoyers
Acked-by: Steven Rostedt
NAKed-by: Ingo Molnar
CC: Thomas Gleixner
CC: David Howells
CC: Greg Kroah-Hartman
Signed-off-by: Rusty Russell
12 Mar, 2014
2 commits
-
Describe the return values of tracepoint_probe_register(), including
-ENODEV added by commit:Author: Steven Rostedt
tracing: Warn if a tracepoint is not set via debugfs
Link: http://lkml.kernel.org/r/1394499898-1537-2-git-send-email-mathieu.desnoyers@efficios.com
CC: Ingo Molnar
CC: Frederic Weisbecker
CC: Andrew Morton
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt -
Describe the @data argument (probe private data).
Link: http://lkml.kernel.org/r/1394587948-27878-1-git-send-email-mathieu.desnoyers@efficios.com
Fixes: 38516ab59fbc "tracing: Let tracepoints have data passed to tracepoint callbacks"
CC: Ingo Molnar
CC: Frederic Weisbecker
CC: Andrew Morton
Signed-off-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt
07 Mar, 2014
1 commit
-
Tracepoints were made to allow enabling a tracepoint in a module before that
module was loaded. When a tracepoint is enabled and it does not exist, the
name is stored and will be enabled when the tracepoint is created.The problem with this approach is that when a tracepoint is enabled when
it expects to be there, it gives no warning that it does not exist.To add salt to the wound, if a module is added and sets the FORCED flag, which
can happen if it isn't signed properly, the tracepoint code will not enabled
the tracepoints, but they will be created in the debugfs system! When a user
goes to enable the tracepoint, the tracepoint code will not see it existing
and will think it is to be enabled later AND WILL NOT GIVE A WARNING.The tracing will look like it succeeded but will actually be doing nothing.
This will cause lots of confusion and headaches for developers trying to
figure out why they are not seeing their tracepoints.Link: http://lkml.kernel.org/r/20140213154507.4040fb06@gandalf.local.home
Reported-by: Mathieu Desnoyers
Reported-by: Johannes Berg
Signed-off-by: Steven Rostedt
04 Mar, 2014
2 commits
-
No reason to allocate tp_module structures for modules that have no
tracepoints. This just wastes memory.Fixes: b75ef8b44b1c "Tracepoint: Dissociate from module mutex"
Acked-by: Mathieu Desnoyers
Signed-off-by: Steven Rostedt -
If a module fails to add its tracepoints due to module tainting, do not
create the module event infrastructure in the debugfs directory. As the events
will not work and worse yet, they will silently fail, making the user wonder
why the events they enable do not display anything.Having a warning on module load and the events not visible to the users
will make the cause of the problem much clearer.Link: http://lkml.kernel.org/r/20140227154923.265882695@goodmis.org
Fixes: 6d723736e472 "tracing/events: add support for modules to TRACE_EVENT"
Acked-by: Mathieu Desnoyers
Cc: stable@vger.kernel.org # 2.6.31+
Cc: Rusty Russell
Signed-off-by: Steven Rostedt
30 Apr, 2013
1 commit
-
Pull tracing updates from Steven Rostedt:
"Along with the usual minor fixes and clean ups there are a few major
changes with this pull request.1) Multiple buffers for the ftrace facility
This feature has been requested by many people over the last few
years. I even heard that Google was about to implement it themselves.
I finally had time and cleaned up the code such that you can now
create multiple instances of the ftrace buffer and have different
events go to different buffers. This way, a low frequency event will
not be lost in the noise of a high frequency event.Note, currently only events can go to different buffers, the tracers
(ie function, function_graph and the latency tracers) still can only
be written to the main buffer.2) The function tracer triggers have now been extended.
The function tracer had two triggers. One to enable tracing when a
function is hit, and one to disable tracing. Now you can record a
stack trace on a single (or many) function(s), take a snapshot of the
buffer (copy it to the snapshot buffer), and you can enable or disable
an event to be traced when a function is hit.3) A perf clock has been added.
A "perf" clock can be chosen to be used when tracing. This will cause
ftrace to use the same clock as perf uses, and hopefully this will
make it easier to interleave the perf and ftrace data for analysis."* tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits)
tracepoints: Prevent null probe from being added
tracing: Compare to 1 instead of zero for is_signed_type()
tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT
ftrace: Get rid of ftrace_profile_bits
tracing: Check return value of tracing_init_dentry()
tracing: Get rid of unneeded key calculation in ftrace_hash_move()
tracing: Reset ftrace_graph_filter_enabled if count is zero
tracing: Fix off-by-one on allocating stat->pages
kernel: tracing: Use strlcpy instead of strncpy
tracing: Update debugfs README file
tracing: Fix ftrace_dump()
tracing: Rename trace_event_mutex to trace_event_sem
tracing: Fix comment about prefix in arch_syscall_match_sym_name()
tracing: Convert trace_destroy_fields() to static
tracing: Move find_event_field() into trace_events.c
tracing: Use TRACE_MAX_PRINT instead of constant
tracing: Use pr_warn_once instead of open coded implementation
ring-buffer: Add ring buffer startup selftest
tracing: Bring Documentation/trace/ftrace.txt up to date
tracing: Add "perf" trace_clock
...Conflicts:
kernel/trace/ftrace.c
kernel/trace/trace.c
20 Apr, 2013
1 commit
-
Somehow tracepoint_entry_add_probe() function allows a null probe function.
And, this may lead to unexpected results since the number of probe
functions in an entry can be counted by checking whether a probe is null
or not in the for-loop.
This patch prevents a null probe from being added.
In tracepoint_entry_remove_probe() function, checking probe parameter
within the for-loop is moved out for code efficiency, leaving the null probe
feature which removes all probe functions in the entry.Link: http://lkml.kernel.org/r/1365991995-19445-1-git-send-email-kpark3469@gmail.com
Reviewed-by: Mathieu Desnoyers
Acked-by: Mathieu Desnoyers
Signed-off-by: Sahara
Signed-off-by: Steven Rostedt
28 Feb, 2013
1 commit
-
I'm not sure why, but the hlist for each entry iterators were conceived
list_for_each_entry(pos, head, member)
The hlist ones were greedy and wanted an extra parameter:
hlist_for_each_entry(tpos, pos, head, member)
Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.Besides the semantic patch, there was some manual work required:
- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.The semantic patch which is mostly the work of Peter Senna Tschudin is here:
@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;type T;
expression a,c,d,e;
identifier b;
statement S;
@@-T b;
[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin
Acked-by: Paul E. McKenney
Signed-off-by: Sasha Levin
Cc: Wu Fengguang
Cc: Marcelo Tosatti
Cc: Gleb Natapov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
