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9687bbf219
6279 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Steven Rostedt
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9687bbf219 |
ftrace: Use guard to take the ftrace_lock in release_probe()
The ftrace_lock is held throughout the entire release_probe() function. Use guard to simplify any exit paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071308.250787901@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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1432afb50d |
ftrace: Use guard to lock ftrace_lock in cache_mod()
The ftrace_lock is held throughout cache_mod(), use guard to simplify the error paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071308.088458856@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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06294cf045 |
ftrace: Use guard for match_records()
The ftrace_lock is held for most of match_records() until the end of the function. Use guard to make error paths simpler. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071307.927146604@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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6348a3fa72 |
fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()
The ftrace_lock is held throughout unregister_ftrace_graph(), use a guard to simplify the error paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071307.770550792@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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434098485b |
fgraph: Give ret_stack its own kmem cache
The ret_stack (shadow stack used by function graph infrastructure) is created for every task on the system when function graph is enabled. Give it its own kmem_cache. This will make it easier to see how much memory is being used specifically for function graph shadow stacks. In the future, this size may change and may not be a power of two. Having its own cache can also keep it from fragmenting memory. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Link: https://lore.kernel.org/20241026063210.7d4910a7@rorschach.local.home Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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6ea8b69da6 |
fgraph: Separate size of ret_stack from PAGE_SIZE
The ret_stack (shadow stack used by function graph infrastructure) is currently defined as PAGE_SIZE. But some architectures which have 64K PAGE_SIZE, this is way overkill. Also there's an effort to allow the PAGE_SIZE to be defined at boot up. Hard code it for now to 4096. In the future, this size may change and even be dependent on specific architectures. Link: https://lore.kernel.org/all/e5067bb8-0fcd-4739-9bca-0e872037d5a1@arm.com/ Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241019152951.053f9646@rorschach.local.home Suggested-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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81ec38ee9d |
Fixes for function graph:
- Fix missing mutex unlock in error path of register_ftrace_graph() A previous fix added a return on an error path and forgot to unlock the mutex. Instead of dealing with error paths, use guard(mutex) as the mutex is just released at the exit of the function anyway. Other functions in this file should be updated with this, but that's a cleanup and not a fix. - Change cpuhp setup name to be consistent with other cpuhp states The same fix that the above patch fixes added a cpuhp_setup_state() call with the name of "fgraph_idle_init". I was informed that it should instead be something like: "fgraph:online". Update that too. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZxydTRQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qsE/APoDcsqqaDJvQ0OsMqVaPdHoj2IUkU4M yueb6U/Kyq1m4wEA259W1PZuQlM0Vo0yJM1w2YIAH18UpO09ZroLnbWoUAc= =2sS+ -----END PGP SIGNATURE----- Merge tag 'ftrace-v6.12-rc4' into trace/ftrace/core In order to modify the code that allocates the shadow stacks, merge the changes that fixed the CPU hotplug shadow stack allocations and build on top of that. Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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a574e7f80e |
fgraph: Change the name of cpuhp state to "fgraph:online"
The cpuhp state name given to cpuhp_setup_state() is "fgraph_idle_init"
which doesn't really conform to the names that are used for cpu hotplug
setups. Instead rename it to "fgraph:online" to be in line with other
states.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20241024222944.473d88c5@rorschach.local.home
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes:
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Li Huafei
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bd3734db86 |
fgraph: Fix missing unlock in register_ftrace_graph()
Use guard(mutex)() to acquire and automatically release ftrace_lock,
fixing the issue of not unlocking when calling cpuhp_setup_state()
fails.
Fixes smatch warning:
kernel/trace/fgraph.c:1317 register_ftrace_graph() warn: inconsistent returns '&ftrace_lock'.
Link: https://lore.kernel.org/20241024155917.1019580-1-lihuafei1@huawei.com
Fixes:
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Steven Rostedt
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fae4078c28 |
fgraph: Allocate ret_stack_list with proper size
The ret_stack_list is an array of ret_stack shadow stacks for the function
graph usage. When the first function graph is enabled, all tasks in the
system get a shadow stack. The ret_stack_list is a 32 element array of
pointers to these shadow stacks. It allocates the shadow stack in batches
(32 stacks at a time), assigns them to running tasks, and continues until
all tasks are covered.
When the function graph shadow stack changed from an array of
ftrace_ret_stack structures to an array of longs, the allocation of
ret_stack_list went from allocating an array of 32 elements to just a
block defined by SHADOW_STACK_SIZE. Luckily, that's defined as PAGE_SIZE
and is much more than enough to hold 32 pointers. But it is way overkill
for the amount needed to allocate.
Change the allocation of ret_stack_list back to a kcalloc() of
FTRACE_RETSTACK_ALLOC_SIZE pointers.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241018215212.23f13f40@rorschach
Fixes:
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Steven Rostedt
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2c02f7375e |
fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
The function graph infrastructure allocates a shadow stack for every task
when enabled. This includes the idle tasks. The first time the function
graph is invoked, the shadow stacks are created and never freed until the
task exits. This includes the idle tasks.
Only the idle tasks that were for online CPUs had their shadow stacks
created when function graph tracing started. If function graph tracing is
enabled and a CPU comes online, the idle task representing that CPU will
not have its shadow stack created, and all function graph tracing for that
idle task will be silently dropped.
Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks.
This will include idle tasks for CPUs that come online during tracing.
This issue can be reproduced by:
# cd /sys/kernel/tracing
# echo 0 > /sys/devices/system/cpu/cpu1/online
# echo 0 > set_ftrace_pid
# echo function_graph > current_tracer
# echo 1 > options/funcgraph-proc
# echo 1 > /sys/devices/system/cpu/cpu1
# grep '<idle>' per_cpu/cpu1/trace | head
Before, nothing would show up.
After:
1) <idle>-0 | 0.811 us | __enqueue_entity();
1) <idle>-0 | 5.626 us | } /* enqueue_entity */
1) <idle>-0 | | dl_server_update_idle_time() {
1) <idle>-0 | | dl_scaled_delta_exec() {
1) <idle>-0 | 0.450 us | arch_scale_cpu_capacity();
1) <idle>-0 | 1.242 us | }
1) <idle>-0 | 1.908 us | }
1) <idle>-0 | | dl_server_start() {
1) <idle>-0 | | enqueue_dl_entity() {
1) <idle>-0 | | task_contending() {
Note, if tracing stops and restarts, the old way would then initialize
the onlined CPUs.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20241018214300.6df82178@rorschach
Fixes:
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Steven Rostedt
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7888af4166 |
ftrace: Make ftrace_regs abstract from direct use
ftrace_regs was created to hold registers that store information to save function parameters, return value and stack. Since it is a subset of pt_regs, it should only be used by its accessor functions. But because pt_regs can easily be taken from ftrace_regs (on most archs), it is tempting to use it directly. But when running on other architectures, it may fail to build or worse, build but crash the kernel! Instead, make struct ftrace_regs an empty structure and have the architectures define __arch_ftrace_regs and all the accessor functions will typecast to it to get to the actual fields. This will help avoid usage of ftrace_regs directly. Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/ Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org> Cc: "x86@kernel.org" <x86@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Naveen N Rao <naveen@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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c73eb02a47 |
fgragh: No need to invoke the function call_filter_check_discard()
The function call_filter_check_discard() has been removed in the commit |
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Masami Hiramatsu (Google)
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0a6c61bc9c |
fgraph: Simplify return address printing in function graph tracer
Simplify return address printing in the function graph tracer by removing fgraph_extras. Since this feature is only used by the function graph tracer and the feature flags can directly accessible from the function graph tracer, fgraph_extras can be removed from the fgraph callback. Cc: Donglin Peng <dolinux.peng@gmail.com> Link: https://lore.kernel.org/172857234900.270774.15378354017601069781.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Oleg Nesterov
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474ec3e849 |
function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr()
After the commit
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Donglin Peng
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21e92806d3 |
function_graph: Support recording and printing the function return address
When using function_graph tracer to analyze the flow of kernel function
execution, it is often necessary to quickly locate the exact line of code
where the call occurs. While this may be easy at times, it can be more
time-consuming when some functions are inlined or the flow is too long.
This feature aims to simplify the process by recording the return address
of traced funcions and printing it when outputing trace logs.
To enhance human readability, the prefix 'ret=' is used for the kernel return
value, while '<-' serves as the prefix for the return address in trace logs to
make it look more like the function tracer.
A new trace option named 'funcgraph-retaddr' has been introduced, and the
existing option 'sym-addr' can be used to control the format of the return
address.
See below logs with both funcgraph-retval and funcgraph-retaddr enabled.
0) | load_elf_binary() { /* <-bprm_execve+0x249/0x600 */
0) | load_elf_phdrs() { /* <-load_elf_binary+0x84/0x1730 */
0) | __kmalloc_noprof() { /* <-load_elf_phdrs+0x4a/0xb0 */
0) 3.657 us | __cond_resched(); /* <-__kmalloc_noprof+0x28c/0x390 ret=0x0 */
0) + 24.335 us | } /* __kmalloc_noprof ret=0xffff8882007f3000 */
0) | kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */
0) | rw_verify_area() { /* <-kernel_read+0x2b/0x50 */
0) | security_file_permission() { /* <-kernel_read+0x2b/0x50 */
0) | selinux_file_permission() { /* <-security_file_permission+0x26/0x40 */
0) | __inode_security_revalidate() { /* <-selinux_file_permission+0x6d/0x140 */
0) 2.034 us | __cond_resched(); /* <-__inode_security_revalidate+0x5f/0x80 ret=0x0 */
0) 6.602 us | } /* __inode_security_revalidate ret=0x0 */
0) 2.214 us | avc_policy_seqno(); /* <-selinux_file_permission+0x107/0x140 ret=0x0 */
0) + 16.670 us | } /* selinux_file_permission ret=0x0 */
0) + 20.809 us | } /* security_file_permission ret=0x0 */
0) + 25.217 us | } /* rw_verify_area ret=0x0 */
0) | __kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */
0) | ext4_file_read_iter() { /* <-__kernel_read+0x160/0x2e0 */
Then, we can use the faddr2line to locate the source code, for example:
$ ./scripts/faddr2line ./vmlinux load_elf_phdrs+0x6c/0xb0
load_elf_phdrs+0x6c/0xb0:
elf_read at fs/binfmt_elf.c:471
(inlined by) load_elf_phdrs at fs/binfmt_elf.c:531
Link: https://lore.kernel.org/20240915032912.1118397-1-dolinux.peng@gmail.com
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409150605.HgUmU8ea-lkp@intel.com/
Signed-off-by: Donglin Peng <dolinux.peng@gmail.com>
[ Rebased to handle text_delta offsets ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Steven Rostedt
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f1f36e22be |
ftrace: Have calltime be saved in the fgraph storage
The calltime field in the shadow stack frame is only used by the function graph tracer and profiler. But now that there's other users of the function graph infrastructure, this adds overhead and wastes space on the shadow stack. Move the calltime to the fgraph data storage, where the function graph and profiler entry functions will save it in its own graph storage and retrieve it in its exit functions. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <olsajiri@gmail.com> Link: https://lore.kernel.org/20240914214827.096968730@goodmis.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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3c9880f3ab |
ftrace: Use a running sleeptime instead of saving on shadow stack
The fgraph "sleep-time" option tells the function graph tracer and the profiler whether to include the time a function "sleeps" (is scheduled off the CPU) in its duration for the function. By default it is true, which means the duration of a function is calculated by the timestamp of when the function was entered to the timestamp of when it exits. If the "sleep-time" option is disabled, it needs to remove the time that the task was not running on the CPU during the function. Currently it is done in a sched_switch tracepoint probe where it moves the "calltime" (time of entry of the function) forward by the sleep time calculated. It updates all the calltime in the shadow stack. This is time consuming for those users of the function graph tracer that does not care about the sleep time. Instead, add a "ftrace_sleeptime" to the task_struct that gets the sleep time added each time the task wakes up. Then have the function entry save the current "ftrace_sleeptime" and on function exit, move the calltime forward by the difference of the current "ftrace_sleeptime" from the saved sleeptime. This removes one dependency of "calltime" needed to be on the shadow stack. It also simplifies the code that removes the sleep time of functions. TODO: Only enable the sched_switch tracepoint when this is needed. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <olsajiri@gmail.com> Link: https://lore.kernel.org/20240914214826.938908568@goodmis.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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a312a0f783 |
fgraph: Use fgraph data to store subtime for profiler
Instead of having the "subtime" for the function profiler in the infrastructure ftrace_ret_stack structure, have it use the fgraph data reserve and retrieve functions. This will keep the limited shadow stack from wasting 8 bytes for something that is seldom used. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <olsajiri@gmail.com> Link: https://lore.kernel.org/20240914214826.780323141@goodmis.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Masami Hiramatsu (Google)
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c54a1a06da |
tracing: Fix function timing profiler to initialize hashtable
Since the new fgraph requires to initialize fgraph_ops.ops.func_hash before
calling register_ftrace_graph(), initialize it with default (tracing all
functions) parameter.
Cc: stable@vger.kernel.org
Fixes:
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Al Viro
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cb787f4ac0 |
[tree-wide] finally take no_llseek out
no_llseek had been defined to NULL two years ago, in commit
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Linus Torvalds
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5159938e10 |
Probes updates for v6.12:
- uprobes: make trace_uprobe->nhit counter a per-CPU one
This makes uprobe event's hit counter per-CPU for improving
scalability on multi-core environment.
- kprobes: Remove obsoleted declaration for init_test_probes
Remove unused init_test_probes() from header.
- Raw tracepoint probe supports raw tracepoint events on modules.
The tracepoint events using fprobe were introduced in v6.5, but
tracepoints can be compiled in modules. This supports such a case.
This includes the following improvements.
. tracepoint: add a function for iterating over all tracepoints in
all modules.
. tracepoint: Add a function for iterating over tracepoints in a
module.
. tracing/fprobe: Support raw tracepoint events on modules.
. tracing/fprobe: Support raw tracepoints on future loaded modules.
This allows user to add tracepoint events on modules which is
not loaded yet.
. selftests/tracing: Add a test for tracepoint events on modules.
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Merge tag 'probes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
- uprobes: make trace_uprobe->nhit counter a per-CPU one
This makes uprobe event's hit counter per-CPU for improving
scalability on multi-core environment
- kprobes: Remove obsoleted declaration for init_test_probes
Remove unused init_test_probes() from header
- Raw tracepoint probe supports raw tracepoint events on modules:
- add a function for iterating over all tracepoints in all modules
- add a function for iterating over tracepoints in a module
- support raw tracepoint events on modules
- support raw tracepoints on future loaded modules
- add a test for tracepoint events on modules"
* tag 'probes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
sefltests/tracing: Add a test for tracepoint events on modules
tracing/fprobe: Support raw tracepoints on future loaded modules
tracing/fprobe: Support raw tracepoint events on modules
tracepoint: Support iterating tracepoints in a loading module
tracepoint: Support iterating over tracepoints on modules
kprobes: Remove obsoleted declaration for init_test_probes
uprobes: turn trace_uprobe's nhit counter to be per-CPU one
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Masami Hiramatsu (Google)
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57a7e6de9e |
tracing/fprobe: Support raw tracepoints on future loaded modules
Support raw tracepoint events on future loaded (unloaded) modules. This allows user to create raw tracepoint events which can be used from module's __init functions. Note: since the kernel does not have any information about the tracepoints in the unloaded modules, fprobe events can not check whether the tracepoint exists nor extend the BTF based arguments. Link: https://lore.kernel.org/all/172397780593.286558.18360375226968537828.stgit@devnote2/ Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> |
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Masami Hiramatsu (Google)
|
67e9a9ee47 |
tracing/fprobe: Support raw tracepoint events on modules
Support raw tracepoint event on module by fprobe events. Since it only uses for_each_kernel_tracepoint() to find a tracepoint, the tracepoints on modules are not handled. Thus if user specified a tracepoint on a module, it shows an error. This adds new for_each_module_tracepoint() API to tracepoint subsystem, and uses it to find tracepoints on modules. Link: https://lore.kernel.org/all/172397779651.286558.15903703620679186867.stgit@devnote2/ Reported-by: don <zds100@gmail.com> Closes: https://lore.kernel.org/all/20240530215718.aeec973a1d0bf058d39cb1e3@kernel.org/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> |
||
|
Andrii Nakryiko
|
10cdb82aa7 |
uprobes: turn trace_uprobe's nhit counter to be per-CPU one
trace_uprobe->nhit counter is not incremented atomically, so its value is questionable in when uprobe is hit on multiple CPUs simultaneously. Also, doing this shared counter increment across many CPUs causes heavy cache line bouncing, limiting uprobe/uretprobe performance scaling with number of CPUs. Solve both problems by making this a per-CPU counter. Link: https://lore.kernel.org/all/20240813203409.3985398-1-andrii@kernel.org/ Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> |
||
|
Linus Torvalds
|
af9c191ac2 |
ring-buffer: Updates for v6.12:
- Merged v6.11-rc3 into trace/ring-buffer/core
The v6.10 ring buffer pull request was not made due to Mathieu Desnoyers
making a comment to the pull request. Mathieu and I resolved it on IRC,
but we did not let Linus know that it was resolved. Linus did not do the
pull thinking it still had some unresolved issues.
The ring buffer work for 6.12 was dependent on both this pull request as
well as the reserve_mem kernel command line option that was going upstream
through the memory management tree. The ring buffer repo was being used by
others so it could not be rebased. In order to continue the work, the
v6.11-rc3 branch was pulled in to get access to the reserve_mem work.
This has the 6.11 pull request that did not make it into 6.11, which was:
tracing/ring-buffer: Have persistent buffer across reboots
This allows for the tracing instance ring buffer to stay persistent across
reboots. The way this is done is by adding to the kernel command line:
trace_instance=boot_map@0x285400000:12M
This will reserve 12 megabytes at the address 0x285400000, and then map
the tracing instance "boot_map" ring buffer to that memory. This will
appear as a normal instance in the tracefs system:
/sys/kernel/tracing/instances/boot_map
A user could enable tracing in that instance, and on reboot or kernel
crash, if the memory is not wiped by the firmware, it will recreate the
trace in that instance. For example, if one was debugging a shutdown of a
kernel reboot:
# cd /sys/kernel/tracing
# echo function > instances/boot_map/current_tracer
# reboot
[..]
# cd /sys/kernel/tracing
# tail instances/boot_map/trace
swapper/0-1 [000] d..1. 164.549800: restore_boot_irq_mode <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549801: native_restore_boot_irq_mode <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549802: disconnect_bsp_APIC <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549811: hpet_disable <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549812: iommu_shutdown_noop <-native_machine_restart
swapper/0-1 [000] d..1. 164.549813: native_machine_emergency_restart <-__do_sys_reboot
swapper/0-1 [000] d..1. 164.549813: tboot_shutdown <-native_machine_emergency_restart
swapper/0-1 [000] d..1. 164.549820: acpi_reboot <-native_machine_emergency_restart
swapper/0-1 [000] d..1. 164.549821: acpi_reset <-acpi_reboot
swapper/0-1 [000] d..1. 164.549822: acpi_os_write_port <-acpi_reboot
On reboot, the buffer is examined to make sure it is valid. The validation
check even steps through every event to make sure the meta data of the
event is correct. If any test fails, it will simply reset the buffer, and
the buffer will be empty on boot.
The new changes for 6.12 are:
- Allow the tracing persistent boot buffer to use the "reserve_mem" option
Instead of having the admin find a physical address to store the persistent
buffer, which can be very tedious if they have to administrate several
different machines, allow them to use the "reserve_mem" option that will
find a location for them. It is not as reliable because of KASLR, as the
loading of the kernel in different locations can cause the memory
allocated to be inconsistent. Booting with "nokaslr" can make reserve_mem
more reliable.
- Have function graph tracer handle offsets from a previous boot.
The ring buffer output from a previous boot may have different addresses
due to kaslr. Have the function graph tracer handle these by using the
delta from the previous boot to the new boot address space.
- Only reset the saved meta offset when the buffer is started or reset
In the persistent memory meta data, it holds the previous address space
information, so that it can calculate the delta to have function tracing
work. But this gets updated after being read to hold the new address
space. But if the buffer isn't used for that boot, on reboot, the delta is
now calculated from the previous boot and not the boot that holds the data
in the ring buffer. This causes the functions not to be shown. Do not save
the address space information of the current kernel until it is being
recorded.
- Add a magic variable to test the valid meta data
Add a magic variable in the meta data that can also be used for
validation. The validator of the previous buffer doesn't need this magic
data, but it can be used if the meta data is changed by a new kernel, which
may have the same format that passes the validator but is used
differently. This magic number can also be used as a "versioning" of the
meta data.
- Align user space mapped ring buffer sub buffers to improve TLB entries
Linus mentioned that the mapped ring buffer sub buffers were misaligned
between the meta page and the sub-buffers, so that if the sub-buffers were
bigger than PAGE_SIZE, it wouldn't allow the TLB to use bigger entries.
- Add new kernel command line "traceoff" to disable tracing on boot for instances
If tracing is enabled for a boot instance, there needs a way to be able to
disable it on boot so that new events do not get entered into the ring
buffer and be mixed with events from a previous boot, as that can be
confusing.
- Allow trace_printk() to go to other instances
Currently, trace_printk() can only go to the top level instance. When
debugging with a persistent buffer, it is really useful to be able to add
trace_printk() to go to that buffer, so that you have access to them after
a crash.
- Do not use "bin_printk()" for traces to a boot instance
The bin_printk() saves only a pointer to the printk format in the ring
buffer, as the reader of the buffer can still have access to it. But this
is not the case if the buffer is from a previous boot. If the
trace_printk() is going to a "persistent" buffer, it will use the slower
version that writes the printk format into the buffer.
- Add command line option to allow trace_printk() to go to an instance
Allow the kernel command line to define which instance the trace_printk()
goes to, instead of forcing the admin to set it for every boot via the
tracefs options.
- Start a document that explains how to use tracefs to debug the kernel
- Add some more kernel selftests to test user mapped ring buffer
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Merge tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
- tracing/ring-buffer: persistent buffer across reboots
This allows for the tracing instance ring buffer to stay persistent
across reboots. The way this is done is by adding to the kernel
command line:
trace_instance=boot_map@0x285400000:12M
This will reserve 12 megabytes at the address 0x285400000, and then
map the tracing instance "boot_map" ring buffer to that memory. This
will appear as a normal instance in the tracefs system:
/sys/kernel/tracing/instances/boot_map
A user could enable tracing in that instance, and on reboot or kernel
crash, if the memory is not wiped by the firmware, it will recreate
the trace in that instance. For example, if one was debugging a
shutdown of a kernel reboot:
# cd /sys/kernel/tracing
# echo function > instances/boot_map/current_tracer
# reboot
[..]
# cd /sys/kernel/tracing
# tail instances/boot_map/trace
swapper/0-1 [000] d..1. 164.549800: restore_boot_irq_mode <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549801: native_restore_boot_irq_mode <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549802: disconnect_bsp_APIC <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549811: hpet_disable <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549812: iommu_shutdown_noop <-native_machine_restart
swapper/0-1 [000] d..1. 164.549813: native_machine_emergency_restart <-__do_sys_reboot
swapper/0-1 [000] d..1. 164.549813: tboot_shutdown <-native_machine_emergency_restart
swapper/0-1 [000] d..1. 164.549820: acpi_reboot <-native_machine_emergency_restart
swapper/0-1 [000] d..1. 164.549821: acpi_reset <-acpi_reboot
swapper/0-1 [000] d..1. 164.549822: acpi_os_write_port <-acpi_reboot
On reboot, the buffer is examined to make sure it is valid. The
validation check even steps through every event to make sure the meta
data of the event is correct. If any test fails, it will simply reset
the buffer, and the buffer will be empty on boot.
- Allow the tracing persistent boot buffer to use the "reserve_mem"
option
Instead of having the admin find a physical address to store the
persistent buffer, which can be very tedious if they have to
administrate several different machines, allow them to use the
"reserve_mem" option that will find a location for them. It is not as
reliable because of KASLR, as the loading of the kernel in different
locations can cause the memory allocated to be inconsistent. Booting
with "nokaslr" can make reserve_mem more reliable.
- Have function graph tracer handle offsets from a previous boot.
The ring buffer output from a previous boot may have different
addresses due to kaslr. Have the function graph tracer handle these
by using the delta from the previous boot to the new boot address
space.
- Only reset the saved meta offset when the buffer is started or reset
In the persistent memory meta data, it holds the previous address
space information, so that it can calculate the delta to have
function tracing work. But this gets updated after being read to hold
the new address space. But if the buffer isn't used for that boot, on
reboot, the delta is now calculated from the previous boot and not
the boot that holds the data in the ring buffer. This causes the
functions not to be shown. Do not save the address space information
of the current kernel until it is being recorded.
- Add a magic variable to test the valid meta data
Add a magic variable in the meta data that can also be used for
validation. The validator of the previous buffer doesn't need this
magic data, but it can be used if the meta data is changed by a new
kernel, which may have the same format that passes the validator but
is used differently. This magic number can also be used as a
"versioning" of the meta data.
- Align user space mapped ring buffer sub buffers to improve TLB
entries
Linus mentioned that the mapped ring buffer sub buffers were
misaligned between the meta page and the sub-buffers, so that if the
sub-buffers were bigger than PAGE_SIZE, it wouldn't allow the TLB to
use bigger entries.
- Add new kernel command line "traceoff" to disable tracing on boot for
instances
If tracing is enabled for a boot instance, there needs a way to be
able to disable it on boot so that new events do not get entered into
the ring buffer and be mixed with events from a previous boot, as
that can be confusing.
- Allow trace_printk() to go to other instances
Currently, trace_printk() can only go to the top level instance. When
debugging with a persistent buffer, it is really useful to be able to
add trace_printk() to go to that buffer, so that you have access to
them after a crash.
- Do not use "bin_printk()" for traces to a boot instance
The bin_printk() saves only a pointer to the printk format in the
ring buffer, as the reader of the buffer can still have access to it.
But this is not the case if the buffer is from a previous boot. If
the trace_printk() is going to a "persistent" buffer, it will use the
slower version that writes the printk format into the buffer.
- Add command line option to allow trace_printk() to go to an instance
Allow the kernel command line to define which instance the
trace_printk() goes to, instead of forcing the admin to set it for
every boot via the tracefs options.
- Start a document that explains how to use tracefs to debug the kernel
- Add some more kernel selftests to test user mapped ring buffer
* tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (28 commits)
selftests/ring-buffer: Handle meta-page bigger than the system
selftests/ring-buffer: Verify the entire meta-page padding
tracing/Documentation: Start a document on how to debug with tracing
tracing: Add option to set an instance to be the trace_printk destination
tracing: Have trace_printk not use binary prints if boot buffer
tracing: Allow trace_printk() to go to other instance buffers
tracing: Add "traceoff" flag to boot time tracing instances
ring-buffer: Align meta-page to sub-buffers for improved TLB usage
ring-buffer: Add magic and struct size to boot up meta data
ring-buffer: Don't reset persistent ring-buffer meta saved addresses
tracing/fgraph: Have fgraph handle previous boot function addresses
tracing: Allow boot instances to use reserve_mem boot memory
tracing: Fix ifdef of snapshots to not prevent last_boot_info file
ring-buffer: Use vma_pages() helper function
tracing: Fix NULL vs IS_ERR() check in enable_instances()
tracing: Add last boot delta offset for stack traces
tracing: Update function tracing output for previous boot buffer
tracing: Handle old buffer mappings for event strings and functions
tracing/ring-buffer: Add last_boot_info file to boot instance
ring-buffer: Save text and data locations in mapped meta data
...
|
||
|
Linus Torvalds
|
440b652328 |
bpf-next-6.12
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Merge tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with
corresponding support in LLVM.
It is similar to existing 'no_caller_saved_registers' attribute in
GCC/LLVM with a provision for backward compatibility. It allows
compilers generate more efficient BPF code assuming the verifier or
JITs will inline or partially inline a helper/kfunc with such
attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast,
bpf_get_smp_processor_id are the first set of such helpers.
- Harden and extend ELF build ID parsing logic.
When called from sleepable context the relevants parts of ELF file
will be read to find and fetch .note.gnu.build-id information. Also
harden the logic to avoid TOCTOU, overflow, out-of-bounds problems.
- Improvements and fixes for sched-ext:
- Allow passing BPF iterators as kfunc arguments
- Make the pointer returned from iter_next method trusted
- Fix x86 JIT convergence issue due to growing/shrinking conditional
jumps in variable length encoding
- BPF_LSM related:
- Introduce few VFS kfuncs and consolidate them in
fs/bpf_fs_kfuncs.c
- Enforce correct range of return values from certain LSM hooks
- Disallow attaching to other LSM hooks
- Prerequisite work for upcoming Qdisc in BPF:
- Allow kptrs in program provided structs
- Support for gen_epilogue in verifier_ops
- Important fixes:
- Fix uprobe multi pid filter check
- Fix bpf_strtol and bpf_strtoul helpers
- Track equal scalars history on per-instruction level
- Fix tailcall hierarchy on x86 and arm64
- Fix signed division overflow to prevent INT_MIN/-1 trap on x86
- Fix get kernel stack in BPF progs attached to tracepoint:syscall
- Selftests:
- Add uprobe bench/stress tool
- Generate file dependencies to drastically improve re-build time
- Match JIT-ed and BPF asm with __xlated/__jited keywords
- Convert older tests to test_progs framework
- Add support for RISC-V
- Few fixes when BPF programs are compiled with GCC-BPF backend
(support for GCC-BPF in BPF CI is ongoing in parallel)
- Add traffic monitor
- Enable cross compile and musl libc
* tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits)
btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version
btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug
btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh
bpf: Call the missed kfree() when there is no special field in btf
bpf: Call the missed btf_record_free() when map creation fails
selftests/bpf: Add a test case to write mtu result into .rodata
selftests/bpf: Add a test case to write strtol result into .rodata
selftests/bpf: Rename ARG_PTR_TO_LONG test description
selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test
bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types
bpf: Fix helper writes to read-only maps
bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers
bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit
selftests/bpf: Add tests for sdiv/smod overflow cases
bpf: Fix a sdiv overflow issue
libbpf: Add bpf_object__token_fd accessor
docs/bpf: Add missing BPF program types to docs
docs/bpf: Add constant values for linkages
bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
...
|
||
|
Linus Torvalds
|
2004cef11e |
In the v6.12 scheduler development cycle we had 63 commits from 18 contributors:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot de Oliveira's
last major contribution to the kernel:
"SCHED_DEADLINE servers can help fixing starvation issues of low priority
tasks (e.g., SCHED_OTHER) when higher priority tasks monopolize CPU
cycles. Today we have RT Throttling; DEADLINE servers should be able to
replace and improve that."
(Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes,
Youssef Esmat, Huang Shijie)
- Preparatory changes for sched_ext integration:
- Use set_next_task(.first) where required
- Fix up set_next_task() implementations
- Clean up DL server vs. core sched
- Split up put_prev_task_balance()
- Rework pick_next_task()
- Combine the last put_prev_task() and the first set_next_task()
- Rework dl_server
- Add put_prev_task(.next)
(Peter Zijlstra, with a fix by Tejun Heo)
- Complete the EEVDF transition and refine EEVDF scheduling:
- Implement delayed dequeue
- Allow shorter slices to wakeup-preempt
- Use sched_attr::sched_runtime to set request/slice suggestion
- Document the new feature flags
- Remove unused and duplicate-functionality fields
- Simplify & unify pick_next_task_fair()
- Misc debuggability enhancements
(Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann,
Valentin Schneider and Chuyi Zhou)
- Initialize the vruntime of a new task when it is first enqueued,
resulting in significant decrease in latency of newly woken tasks.
(Zhang Qiao)
- Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
(K Prateek Nayak, Peter Zijlstra)
- Clean up and clarify the usage of Clean up usage of rt_task()
(Qais Yousef)
- Preempt SCHED_IDLE entities in strict cgroup hierarchies
(Tianchen Ding)
- Clarify the documentation of time units for deadline scheduler
parameters. (Christian Loehle)
- Remove the HZ_BW chicken-bit feature flag introduced a year ago,
the original change seems to be working fine.
(Phil Auld)
- Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
Peilin He, Qais Yousefm and Vincent Guittot)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
de Oliveira's last major contribution to the kernel:
"SCHED_DEADLINE servers can help fixing starvation issues of low
priority tasks (e.g., SCHED_OTHER) when higher priority tasks
monopolize CPU cycles. Today we have RT Throttling; DEADLINE
servers should be able to replace and improve that."
(Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
Esmat, Huang Shijie)
- Preparatory changes for sched_ext integration:
- Use set_next_task(.first) where required
- Fix up set_next_task() implementations
- Clean up DL server vs. core sched
- Split up put_prev_task_balance()
- Rework pick_next_task()
- Combine the last put_prev_task() and the first set_next_task()
- Rework dl_server
- Add put_prev_task(.next)
(Peter Zijlstra, with a fix by Tejun Heo)
- Complete the EEVDF transition and refine EEVDF scheduling:
- Implement delayed dequeue
- Allow shorter slices to wakeup-preempt
- Use sched_attr::sched_runtime to set request/slice suggestion
- Document the new feature flags
- Remove unused and duplicate-functionality fields
- Simplify & unify pick_next_task_fair()
- Misc debuggability enhancements
(Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
Schneider and Chuyi Zhou)
- Initialize the vruntime of a new task when it is first enqueued,
resulting in significant decrease in latency of newly woken tasks
(Zhang Qiao)
- Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
(K Prateek Nayak, Peter Zijlstra)
- Clean up and clarify the usage of Clean up usage of rt_task()
(Qais Yousef)
- Preempt SCHED_IDLE entities in strict cgroup hierarchies
(Tianchen Ding)
- Clarify the documentation of time units for deadline scheduler
parameters (Christian Loehle)
- Remove the HZ_BW chicken-bit feature flag introduced a year ago,
the original change seems to be working fine (Phil Auld)
- Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
Peilin He, Qais Yousefm and Vincent Guittot)
* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
sched/cpufreq: Use NSEC_PER_MSEC for deadline task
cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
sched/deadline: Clarify nanoseconds in uapi
sched/deadline: Convert schedtool example to chrt
sched/debug: Fix the runnable tasks output
sched: Fix sched_delayed vs sched_core
kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
kthread: Fix task state in kthread worker if being frozen
sched/pelt: Use rq_clock_task() for hw_pressure
sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
sched: Add put_prev_task(.next)
sched: Rework dl_server
sched: Combine the last put_prev_task() and the first set_next_task()
sched: Rework pick_next_task()
sched: Split up put_prev_task_balance()
sched: Clean up DL server vs core sched
sched: Fixup set_next_task() implementations
sched: Use set_next_task(.first) where required
sched/fair: Properly deactivate sched_delayed task upon class change
...
|
||
|
Linus Torvalds
|
9f0c253ddd |
Performance events changes for v6.12:
- Implement per-PMU context rescheduling to significantly improve single-PMU
performance, and related cleanups/fixes. (by Peter Zijlstra and Namhyung Kim)
- Fix ancient bug resulting in a lot of events being dropped erroneously
at higher sampling frequencies. (by Luo Gengkun)
- uprobes enhancements:
- Implement RCU-protected hot path optimizations for better performance:
"For baseline vs SRCU, peak througput increased from 3.7 M/s (million uprobe
triggerings per second) up to about 8 M/s. For uretprobes it's a bit more
modest with bump from 2.4 M/s to 5 M/s.
For SRCU vs RCU Tasks Trace, peak throughput for uprobes increases further from
8 M/s to 10.3 M/s (+28%!), and for uretprobes from 5.3 M/s to 5.8 M/s (+11%),
as we have more work to do on uretprobes side.
Even single-thread (no contention) performance is slightly better: 3.276 M/s to
3.396 M/s (+3.5%) for uprobes, and 2.055 M/s to 2.174 M/s (+5.8%)
for uretprobes."
(by Andrii Nakryiko et al)
- Document mmap_lock, don't abuse get_user_pages_remote(). (by Oleg Nesterov)
- Cleanups & fixes to prepare for future work:
- Remove uprobe_register_refctr()
- Simplify error handling for alloc_uprobe()
- Make uprobe_register() return struct uprobe *
- Fold __uprobe_unregister() into uprobe_unregister()
- Shift put_uprobe() from delete_uprobe() to uprobe_unregister()
- BPF: Fix use-after-free in bpf_uprobe_multi_link_attach()
(by Oleg Nesterov)
- New feature & ABI extension: allow events to use PERF_SAMPLE READ with
inheritance, enabling sample based profiling of a group of counters over
a hierarchy of processes or threads. (by Ben Gainey)
- Intel uncore & power events updates:
- Add Arrow Lake and Lunar Lake support
- Add PERF_EV_CAP_READ_SCOPE
- Clean up and enhance cpumask and hotplug support
(by Kan Liang)
- Add LNL uncore iMC freerunning support
- Use D0:F0 as a default device
(by Zhenyu Wang)
- Intel PT: fix AUX snapshot handling race. (by Adrian Hunter)
- Misc fixes and cleanups. (by James Clark, Jiri Olsa, Oleg Nesterov and Peter Zijlstra)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar:
- Implement per-PMU context rescheduling to significantly improve
single-PMU performance, and related cleanups/fixes (Peter Zijlstra
and Namhyung Kim)
- Fix ancient bug resulting in a lot of events being dropped
erroneously at higher sampling frequencies (Luo Gengkun)
- uprobes enhancements:
- Implement RCU-protected hot path optimizations for better
performance:
"For baseline vs SRCU, peak througput increased from 3.7 M/s
(million uprobe triggerings per second) up to about 8 M/s. For
uretprobes it's a bit more modest with bump from 2.4 M/s to
5 M/s.
For SRCU vs RCU Tasks Trace, peak throughput for uprobes
increases further from 8 M/s to 10.3 M/s (+28%!), and for
uretprobes from 5.3 M/s to 5.8 M/s (+11%), as we have more
work to do on uretprobes side.
Even single-thread (no contention) performance is slightly
better: 3.276 M/s to 3.396 M/s (+3.5%) for uprobes, and 2.055
M/s to 2.174 M/s (+5.8%) for uretprobes."
(Andrii Nakryiko et al)
- Document mmap_lock, don't abuse get_user_pages_remote() (Oleg
Nesterov)
- Cleanups & fixes to prepare for future work:
- Remove uprobe_register_refctr()
- Simplify error handling for alloc_uprobe()
- Make uprobe_register() return struct uprobe *
- Fold __uprobe_unregister() into uprobe_unregister()
- Shift put_uprobe() from delete_uprobe() to uprobe_unregister()
- BPF: Fix use-after-free in bpf_uprobe_multi_link_attach()
(Oleg Nesterov)
- New feature & ABI extension: allow events to use PERF_SAMPLE READ
with inheritance, enabling sample based profiling of a group of
counters over a hierarchy of processes or threads (Ben Gainey)
- Intel uncore & power events updates:
- Add Arrow Lake and Lunar Lake support
- Add PERF_EV_CAP_READ_SCOPE
- Clean up and enhance cpumask and hotplug support
(Kan Liang)
- Add LNL uncore iMC freerunning support
- Use D0:F0 as a default device
(Zhenyu Wang)
- Intel PT: fix AUX snapshot handling race (Adrian Hunter)
- Misc fixes and cleanups (James Clark, Jiri Olsa, Oleg Nesterov and
Peter Zijlstra)
* tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
dmaengine: idxd: Clean up cpumask and hotplug for perfmon
iommu/vt-d: Clean up cpumask and hotplug for perfmon
perf/x86/intel/cstate: Clean up cpumask and hotplug
perf: Add PERF_EV_CAP_READ_SCOPE
perf: Generic hotplug support for a PMU with a scope
uprobes: perform lockless SRCU-protected uprobes_tree lookup
rbtree: provide rb_find_rcu() / rb_find_add_rcu()
perf/uprobe: split uprobe_unregister()
uprobes: travers uprobe's consumer list locklessly under SRCU protection
uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks
uprobes: protected uprobe lifetime with SRCU
uprobes: revamp uprobe refcounting and lifetime management
bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
perf/core: Fix small negative period being ignored
perf: Really fix event_function_call() locking
perf: Optimize __pmu_ctx_sched_out()
perf: Add context time freeze
perf: Fix event_function_call() locking
perf: Extract a few helpers
perf: Optimize context reschedule for single PMU cases
...
|
||
|
Linus Torvalds
|
067610ebaa |
RCU pull request for v6.12
This pull request contains the following branches:
context_tracking.15.08.24a: Rename context tracking state related
symbols and remove references to "dynticks" in various context
tracking state variables and related helpers; force
context_tracking_enabled_this_cpu() to be inlined to avoid
leaving a noinstr section.
csd.lock.15.08.24a: Enhance CSD-lock diagnostic reports; add an API
to provide an indication of ongoing CSD-lock stall.
nocb.09.09.24a: Update and simplify RCU nocb code to handle
(de-)offloading of callbacks only for offline CPUs; fix RT
throttling hrtimer being armed from offline CPU.
rcutorture.14.08.24a: Remove redundant rcu_torture_ops get_gp_completed
fields; add SRCU ->same_gp_state and ->get_comp_state
functions; add generic test for NUM_ACTIVE_*RCU_POLL* for
testing RCU and SRCU polled grace periods; add CFcommon.arch
for arch-specific Kconfig options; print number of update types
in rcu_torture_write_types();
add rcutree.nohz_full_patience_delay testing to the TREE07
scenario; add a stall_cpu_repeat module parameter to test
repeated CPU stalls; add argument to limit number of CPUs a
guest OS can use in torture.sh;
rcustall.09.09.24a: Abbreviate RCU CPU stall warnings during CSD-lock
stalls; Allow dump_cpu_task() to be called without disabling
preemption; defer printing stall-warning backtrace when holding
rcu_node lock.
srcu.12.08.24a: Make SRCU gp seq wrap-around faster; add KCSAN checks
for concurrent updates to ->srcu_n_exp_nodelay and
->reschedule_count which are used in heuristics governing
auto-expediting of normal SRCU grace periods and
grace-period-state-machine delays; mark idle SRCU-barrier
callbacks to help identify stuck SRCU-barrier callback.
rcu.tasks.14.08.24a: Remove RCU Tasks Rude asynchronous APIs as they
are no longer used; stop testing RCU Tasks Rude asynchronous
APIs; fix access to non-existent percpu regions; check
processor-ID assumptions during chosen CPU calculation for
callback enqueuing; update description of rtp->tasks_gp_seq
grace-period sequence number; add rcu_barrier_cb_is_done()
to identify whether a given rcu_barrier callback is stuck;
mark idle Tasks-RCU-barrier callbacks; add
*torture_stats_print() functions to print detailed
diagnostics for Tasks-RCU variants; capture start time of
rcu_barrier_tasks*() operation to help distinguish a hung
barrier operation from a long series of barrier operations.
rcu_scaling_tests.15.08.24a:
refscale: Add a TINY scenario to support tests of Tiny RCU
and Tiny SRCU; Optimize process_durations() operation;
rcuscale: Dump stacks of stalled rcu_scale_writer() instances;
dump grace-period statistics when rcu_scale_writer() stalls;
mark idle RCU-barrier callbacks to identify stuck RCU-barrier
callbacks; print detailed grace-period and barrier diagnostics
on rcu_scale_writer() hangs for Tasks-RCU variants; warn if
async module parameter is specified for RCU implementations
that do not have async primitives such as RCU Tasks Rude;
make all writer tasks report upon hang; tolerate repeated
GFP_KERNEL failure in rcu_scale_writer(); use special allocator
for rcu_scale_writer(); NULL out top-level pointers to heap
memory to avoid double-free bugs on modprobe failures; maintain
per-task instead of per-CPU callbacks count to avoid any issues
with migration of either tasks or callbacks; constify struct
ref_scale_ops.
fixes.12.08.24a: Use system_unbound_wq for kfree_rcu work to avoid
disturbing isolated CPUs.
misc.11.08.24a: Warn on unexpected rcu_state.srs_done_tail state;
Better define "atomic" for list_replace_rcu() and
hlist_replace_rcu() routines; annotate struct
kvfree_rcu_bulk_data with __counted_by().
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Merge tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux
Pull RCU updates from Neeraj Upadhyay:
"Context tracking:
- rename context tracking state related symbols and remove references
to "dynticks" in various context tracking state variables and
related helpers
- force context_tracking_enabled_this_cpu() to be inlined to avoid
leaving a noinstr section
CSD lock:
- enhance CSD-lock diagnostic reports
- add an API to provide an indication of ongoing CSD-lock stall
nocb:
- update and simplify RCU nocb code to handle (de-)offloading of
callbacks only for offline CPUs
- fix RT throttling hrtimer being armed from offline CPU
rcutorture:
- remove redundant rcu_torture_ops get_gp_completed fields
- add SRCU ->same_gp_state and ->get_comp_state functions
- add generic test for NUM_ACTIVE_*RCU_POLL* for testing RCU and SRCU
polled grace periods
- add CFcommon.arch for arch-specific Kconfig options
- print number of update types in rcu_torture_write_types()
- add rcutree.nohz_full_patience_delay testing to the TREE07 scenario
- add a stall_cpu_repeat module parameter to test repeated CPU stalls
- add argument to limit number of CPUs a guest OS can use in
torture.sh
rcustall:
- abbreviate RCU CPU stall warnings during CSD-lock stalls
- Allow dump_cpu_task() to be called without disabling preemption
- defer printing stall-warning backtrace when holding rcu_node lock
srcu:
- make SRCU gp seq wrap-around faster
- add KCSAN checks for concurrent updates to ->srcu_n_exp_nodelay and
->reschedule_count which are used in heuristics governing
auto-expediting of normal SRCU grace periods and
grace-period-state-machine delays
- mark idle SRCU-barrier callbacks to help identify stuck
SRCU-barrier callback
rcu tasks:
- remove RCU Tasks Rude asynchronous APIs as they are no longer used
- stop testing RCU Tasks Rude asynchronous APIs
- fix access to non-existent percpu regions
- check processor-ID assumptions during chosen CPU calculation for
callback enqueuing
- update description of rtp->tasks_gp_seq grace-period sequence
number
- add rcu_barrier_cb_is_done() to identify whether a given
rcu_barrier callback is stuck
- mark idle Tasks-RCU-barrier callbacks
- add *torture_stats_print() functions to print detailed diagnostics
for Tasks-RCU variants
- capture start time of rcu_barrier_tasks*() operation to help
distinguish a hung barrier operation from a long series of barrier
operations
refscale:
- add a TINY scenario to support tests of Tiny RCU and Tiny
SRCU
- optimize process_durations() operation
rcuscale:
- dump stacks of stalled rcu_scale_writer() instances and
grace-period statistics when rcu_scale_writer() stalls
- mark idle RCU-barrier callbacks to identify stuck RCU-barrier
callbacks
- print detailed grace-period and barrier diagnostics on
rcu_scale_writer() hangs for Tasks-RCU variants
- warn if async module parameter is specified for RCU implementations
that do not have async primitives such as RCU Tasks Rude
- make all writer tasks report upon hang
- tolerate repeated GFP_KERNEL failure in rcu_scale_writer()
- use special allocator for rcu_scale_writer()
- NULL out top-level pointers to heap memory to avoid double-free
bugs on modprobe failures
- maintain per-task instead of per-CPU callbacks count to avoid any
issues with migration of either tasks or callbacks
- constify struct ref_scale_ops
Fixes:
- use system_unbound_wq for kfree_rcu work to avoid disturbing
isolated CPUs
Misc:
- warn on unexpected rcu_state.srs_done_tail state
- better define "atomic" for list_replace_rcu() and
hlist_replace_rcu() routines
- annotate struct kvfree_rcu_bulk_data with __counted_by()"
* tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (90 commits)
rcu: Defer printing stall-warning backtrace when holding rcu_node lock
rcu/nocb: Remove superfluous memory barrier after bypass enqueue
rcu/nocb: Conditionally wake up rcuo if not already waiting on GP
rcu/nocb: Fix RT throttling hrtimer armed from offline CPU
rcu/nocb: Simplify (de-)offloading state machine
context_tracking: Tag context_tracking_enabled_this_cpu() __always_inline
context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching
rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()
rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()
rcu: Rename rcu_implicit_dynticks_qs() into rcu_watching_snap_recheck()
rcu: Rename dyntick_save_progress_counter() into rcu_watching_snap_save()
rcu: Rename struct rcu_data .exp_dynticks_snap into .exp_watching_snap
rcu: Rename struct rcu_data .dynticks_snap into .watching_snap
rcu: Rename rcu_dynticks_zero_in_eqs() into rcu_watching_zero_in_eqs()
rcu: Rename rcu_dynticks_in_eqs_since() into rcu_watching_snap_stopped_since()
rcu: Rename rcu_dynticks_in_eqs() into rcu_watching_snap_in_eqs()
rcu: Rename rcu_dynticks_eqs_online() into rcu_watching_online()
context_tracking, rcu: Rename rcu_dynticks_curr_cpu_in_eqs() into rcu_is_watching_curr_cpu()
context_tracking, rcu: Rename rcu_dynticks_task*() into rcu_task*()
refscale: Constify struct ref_scale_ops
...
|
||
|
Daniel Borkmann
|
32556ce93b |
bpf: Fix helper writes to read-only maps
Lonial found an issue that despite user- and BPF-side frozen BPF map
(like in case of .rodata), it was still possible to write into it from
a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT}
as arguments.
In check_func_arg() when the argument is as mentioned, the meta->raw_mode
is never set. Later, check_helper_mem_access(), under the case of
PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the
subsequent call to check_map_access_type() and given the BPF map is
read-only it succeeds.
The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT
when results are written into them as opposed to read out of them. The
latter indicates that it's okay to pass a pointer to uninitialized memory
as the memory is written to anyway.
However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM
just with additional alignment requirement. So it is better to just get
rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the
fixed size memory types. For this, add MEM_ALIGNED to additionally ensure
alignment given these helpers write directly into the args via *<ptr> = val.
The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>).
MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated
argument types, since in !MEM_FIXED_SIZE cases the verifier does not know
the buffer size a priori and therefore cannot blindly write *<ptr> = val.
Fixes:
|
||
|
Yonghong Song
|
376bd59e2a |
bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
Salvatore Benedetto reported an issue that when doing syscall tracepoint
tracing the kernel stack is empty. For example, using the following
command line
bpftrace -e 'tracepoint:syscalls:sys_enter_read { print("Kernel Stack\n"); print(kstack()); }'
bpftrace -e 'tracepoint:syscalls:sys_exit_read { print("Kernel Stack\n"); print(kstack()); }'
the output for both commands is
===
Kernel Stack
===
Further analysis shows that pt_regs used for bpf syscall tracepoint
tracing is from the one constructed during user->kernel transition.
The call stack looks like
perf_syscall_enter+0x88/0x7c0
trace_sys_enter+0x41/0x80
syscall_trace_enter+0x100/0x160
do_syscall_64+0x38/0xf0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The ip address stored in pt_regs is from user space hence no kernel
stack is printed.
To fix the issue, kernel address from pt_regs is required.
In kernel repo, there are already a few cases like this. For example,
in kernel/trace/bpf_trace.c, several perf_fetch_caller_regs(fake_regs_ptr)
instances are used to supply ip address or use ip address to construct
call stack.
Instead of allocate fake_regs in the stack which may consume
a lot of bytes, the function perf_trace_buf_alloc() in
perf_syscall_{enter, exit}() is leveraged to create fake_regs,
which will be passed to perf_call_bpf_{enter,exit}().
For the above bpftrace script, I got the following output with this patch:
for tracepoint:syscalls:sys_enter_read
===
Kernel Stack
syscall_trace_enter+407
syscall_trace_enter+407
do_syscall_64+74
entry_SYSCALL_64_after_hwframe+75
===
and for tracepoint:syscalls:sys_exit_read
===
Kernel Stack
syscall_exit_work+185
syscall_exit_work+185
syscall_exit_to_user_mode+305
do_syscall_64+118
entry_SYSCALL_64_after_hwframe+75
===
Reported-by: Salvatore Benedetto <salvabenedetto@meta.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240910214037.3663272-1-yonghong.song@linux.dev
|
||
|
Andrii Nakryiko
|
d4dd9775ec |
bpf: wire up sleepable bpf_get_stack() and bpf_get_task_stack() helpers
Add sleepable implementations of bpf_get_stack() and bpf_get_task_stack() helpers and allow them to be used from sleepable BPF program (e.g., sleepable uprobes). Note, the stack trace IPs capturing itself is not sleepable (that would need to be a separate project), only build ID fetching is sleepable and thus more reliable, as it will wait for data to be paged in, if necessary. For that we make use of sleepable build_id_parse() implementation. Now that build ID related internals in kernel/bpf/stackmap.c can be used both in sleepable and non-sleepable contexts, we need to add additional rcu_read_lock()/rcu_read_unlock() protection around fetching perf_callchain_entry, but with the refactoring in previous commit it's now pretty straightforward. We make sure to do rcu_read_unlock (in sleepable mode only) right before stack_map_get_build_id_offset() call which can sleep. By that time we don't have any more use of perf_callchain_entry. Note, bpf_get_task_stack() will fail for user mode if task != current. And for kernel mode build ID are irrelevant. So in that sense adding sleepable bpf_get_task_stack() implementation is a no-op. It feel right to wire this up for symmetry and completeness, but I'm open to just dropping it until we support `user && crosstask` condition. Reviewed-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240829174232.3133883-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andy Shevchenko
|
4e378158e5 |
tracing: Drop unused helper function to fix the build
A helper function defined but not used. This, in particular,
prevents kernel builds with clang, `make W=1` and CONFIG_WERROR=y:
kernel/trace/trace.c:2229:19: error: unused function 'run_tracer_selftest' [-Werror,-Wunused-function]
2229 | static inline int run_tracer_selftest(struct tracer *type)
| ^~~~~~~~~~~~~~~~~~~
Fix this by dropping unused functions.
See also commit
|
||
|
Steven Rostedt
|
af17814334 |
tracing/osnoise: Fix build when timerlat is not enabled
To fix some critical section races, the interface_lock was added to a few
locations. One of those locations was above where the interface_lock was
declared, so the declaration was moved up before that usage.
Unfortunately, where it was placed was inside a CONFIG_TIMERLAT_TRACER
ifdef block. As the interface_lock is used outside that config, this broke
the build when CONFIG_OSNOISE_TRACER was enabled but
CONFIG_TIMERLAT_TRACER was not.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Helena Anna" <helena.anna.dubel@intel.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Link: https://lore.kernel.org/20240909103231.23a289e2@gandalf.local.home
Fixes:
|
||
|
Jiri Olsa
|
900f362e20 |
bpf: Fix uprobe multi pid filter check
Uprobe multi link does its own process (thread leader) filtering before running the bpf program by comparing task's vm pointers. But as Oleg pointed out there can be processes sharing the vm (CLONE_VM), so we can't just compare task->vm pointers, but instead we need to use same_thread_group call. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/bpf/20240905115124.1503998-2-jolsa@kernel.org |
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Steven Rostedt
|
5bfbcd1ee5 |
tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()
The timerlat interface will get and put the task that is part of the
"kthread" field of the osn_var to keep it around until all references are
released. But here's a race in the "stop_kthread()" code that will call
put_task_struct() on the kthread if it is not a kernel thread. This can
race with the releasing of the references to that task struct and the
put_task_struct() can be called twice when it should have been called just
once.
Take the interface_lock() in stop_kthread() to synchronize this change.
But to do so, the function stop_per_cpu_kthreads() needs to change the
loop from for_each_online_cpu() to for_each_possible_cpu() and remove the
cpu_read_lock(), as the interface_lock can not be taken while the cpu
locks are held. The only side effect of this change is that it may do some
extra work, as the per_cpu variables of the offline CPUs would not be set
anyway, and would simply be skipped in the loop.
Remove unneeded "return;" in stop_kthread().
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240905113359.2b934242@gandalf.local.home
Fixes:
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Steven Rostedt
|
e6a53481da |
tracing/timerlat: Only clear timer if a kthread exists
The timerlat tracer can use user space threads to check for osnoise and
timer latency. If the program using this is killed via a SIGTERM, the
threads are shutdown one at a time and another tracing instance can start
up resetting the threads before they are fully closed. That causes the
hrtimer assigned to the kthread to be shutdown and freed twice when the
dying thread finally closes the file descriptors, causing a use-after-free
bug.
Only cancel the hrtimer if the associated thread is still around. Also add
the interface_lock around the resetting of the tlat_var->kthread.
Note, this is just a quick fix that can be backported to stable. A real
fix is to have a better synchronization between the shutdown of old
threads and the starting of new ones.
Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240905085330.45985730@gandalf.local.home
Fixes:
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Steven Rostedt
|
177e1cc2f4 |
tracing/osnoise: Use a cpumask to know what threads are kthreads
The start_kthread() and stop_thread() code was not always called with the
interface_lock held. This means that the kthread variable could be
unexpectedly changed causing the kthread_stop() to be called on it when it
should not have been, leading to:
while true; do
rtla timerlat top -u -q & PID=$!;
sleep 5;
kill -INT $PID;
sleep 0.001;
kill -TERM $PID;
wait $PID;
done
Causing the following OOPS:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 5 UID: 0 PID: 885 Comm: timerlatu/5 Not tainted 6.11.0-rc4-test-00002-gbc754cc76d1b-dirty #125 a533010b71dab205ad2f507188ce8c82203b0254
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:hrtimer_active+0x58/0x300
Code: 48 c1 ee 03 41 54 48 01 d1 48 01 d6 55 53 48 83 ec 20 80 39 00 0f 85 30 02 00 00 49 8b 6f 30 4c 8d 75 10 4c 89 f0 48 c1 e8 03 <0f> b6 3c 10 4c 89 f0 83 e0 07 83 c0 03 40 38 f8 7c 09 40 84 ff 0f
RSP: 0018:ffff88811d97f940 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88823c6b5b28 RCX: ffffed10478d6b6b
RDX: dffffc0000000000 RSI: ffffed10478d6b6c RDI: ffff88823c6b5b28
RBP: 0000000000000000 R08: ffff88823c6b5b58 R09: ffff88823c6b5b60
R10: ffff88811d97f957 R11: 0000000000000010 R12: 00000000000a801d
R13: ffff88810d8b35d8 R14: 0000000000000010 R15: ffff88823c6b5b28
FS: 0000000000000000(0000) GS:ffff88823c680000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561858ad7258 CR3: 000000007729e001 CR4: 0000000000170ef0
Call Trace:
<TASK>
? die_addr+0x40/0xa0
? exc_general_protection+0x154/0x230
? asm_exc_general_protection+0x26/0x30
? hrtimer_active+0x58/0x300
? __pfx_mutex_lock+0x10/0x10
? __pfx_locks_remove_file+0x10/0x10
hrtimer_cancel+0x15/0x40
timerlat_fd_release+0x8e/0x1f0
? security_file_release+0x43/0x80
__fput+0x372/0xb10
task_work_run+0x11e/0x1f0
? _raw_spin_lock+0x85/0xe0
? __pfx_task_work_run+0x10/0x10
? poison_slab_object+0x109/0x170
? do_exit+0x7a0/0x24b0
do_exit+0x7bd/0x24b0
? __pfx_migrate_enable+0x10/0x10
? __pfx_do_exit+0x10/0x10
? __pfx_read_tsc+0x10/0x10
? ktime_get+0x64/0x140
? _raw_spin_lock_irq+0x86/0xe0
do_group_exit+0xb0/0x220
get_signal+0x17ba/0x1b50
? vfs_read+0x179/0xa40
? timerlat_fd_read+0x30b/0x9d0
? __pfx_get_signal+0x10/0x10
? __pfx_timerlat_fd_read+0x10/0x10
arch_do_signal_or_restart+0x8c/0x570
? __pfx_arch_do_signal_or_restart+0x10/0x10
? vfs_read+0x179/0xa40
? ksys_read+0xfe/0x1d0
? __pfx_ksys_read+0x10/0x10
syscall_exit_to_user_mode+0xbc/0x130
do_syscall_64+0x74/0x110
? __pfx___rseq_handle_notify_resume+0x10/0x10
? __pfx_ksys_read+0x10/0x10
? fpregs_restore_userregs+0xdb/0x1e0
? fpregs_restore_userregs+0xdb/0x1e0
? syscall_exit_to_user_mode+0x116/0x130
? do_syscall_64+0x74/0x110
? do_syscall_64+0x74/0x110
? do_syscall_64+0x74/0x110
entry_SYSCALL_64_after_hwframe+0x71/0x79
RIP: 0033:0x7ff0070eca9c
Code: Unable to access opcode bytes at 0x7ff0070eca72.
RSP: 002b:00007ff006dff8c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007ff0070eca9c
RDX: 0000000000000400 RSI: 00007ff006dff9a0 RDI: 0000000000000003
RBP: 00007ff006dffde0 R08: 0000000000000000 R09: 00007ff000000ba0
R10: 00007ff007004b08 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ff006dff9a0 R14: 0000000000000007 R15: 0000000000000008
</TASK>
Modules linked in: snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hwdep snd_hda_core
---[ end trace 0000000000000000 ]---
This is because it would mistakenly call kthread_stop() on a user space
thread making it "exit" before it actually exits.
Since kthreads are created based on global behavior, use a cpumask to know
when kthreads are running and that they need to be shutdown before
proceeding to do new work.
Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/
This was debugged by using the persistent ring buffer:
Link: https://lore.kernel.org/all/20240823013902.135036960@goodmis.org/
Note, locking was originally used to fix this, but that proved to cause too
many deadlocks to work around:
https://lore.kernel.org/linux-trace-kernel/20240823102816.5e55753b@gandalf.local.home/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240904103428.08efdf4c@gandalf.local.home
Fixes:
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||
|
Peter Zijlstra
|
04b01625da |
perf/uprobe: split uprobe_unregister()
With uprobe_unregister() having grown a synchronize_srcu(), it becomes fairly slow to call. Esp. since both users of this API call it in a loop. Peel off the sync_srcu() and do it once, after the loop. We also need to add uprobe_unregister_sync() into uprobe_register()'s error handling path, as we need to be careful about returning to the caller before we have a guarantee that partially attached consumer won't be called anymore. This is an unlikely slow path and this should be totally fine to be slow in the case of a failed attach. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: "Peter Zijlstra (Intel)" <peterz@infradead.org> Co-developed-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20240903174603.3554182-6-andrii@kernel.org |
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Andrii Nakryiko
|
59da880afe |
uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks
It serves no purpose beyond adding unnecessray argument passed to the filter callback. Just get rid of it, no one is actually using it. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20240903174603.3554182-4-andrii@kernel.org |
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Oleg Nesterov
|
5fe6e308ab |
bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
If bpf_link_prime() fails, bpf_uprobe_multi_link_attach() goes to the
error_free label and frees the array of bpf_uprobe's without calling
bpf_uprobe_unregister().
This leaks bpf_uprobe->uprobe and worse, this frees bpf_uprobe->consumer
without removing it from the uprobe->consumers list.
Fixes:
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Zheng Yejian
|
49aa8a1f4d |
tracing: Avoid possible softlockup in tracing_iter_reset()
In __tracing_open(), when max latency tracers took place on the cpu,
the time start of its buffer would be updated, then event entries with
timestamps being earlier than start of the buffer would be skipped
(see tracing_iter_reset()).
Softlockup will occur if the kernel is non-preemptible and too many
entries were skipped in the loop that reset every cpu buffer, so add
cond_resched() to avoid it.
Cc: stable@vger.kernel.org
Fixes:
|
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Ingo Molnar
|
95c13662b6 |
Merge branch 'perf/urgent' into perf/core, to pick up fixes
This also refreshes the -rc1 based branch to -rc5. Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Steven Rostedt
|
ef2bd81d0c |
tracing: Add option to set an instance to be the trace_printk destination
Add a option "trace_printk_dest" that will make the tracing instance the location that trace_printk() will go to. This is useful if the trace_printk or one of the top level tracers is too noisy and there's a need to separate the two. Then an instance can be created, the trace_printk can be set to go there instead, where it will not be lost in the noise of the top level tracer. Note, only one instance can be the destination of trace_printk at a time. If an instance sets this flag, the instance that had it set will have it cleared. There is always one instance that has this set. By default, that is the top instance. This flag cannot be cleared from the top instance. Doing so will result in an -EINVAL. The only way this flag can be cleared from the top instance is by another instance setting it. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineeth Pillai <vineeth@bitbyteword.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Ross Zwisler <zwisler@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Aring <aahringo@redhat.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Cc: Tomas Glozar <tglozar@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Jonathan Corbet" <corbet@lwn.net> Link: https://lore.kernel.org/20240823014019.545459018@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Steven Rostedt
|
9b7bdf6f6e |
tracing: Have trace_printk not use binary prints if boot buffer
If the persistent boot mapped ring buffer is used for trace_printk(), force it to not use the binary versions. trace_printk() by default uses bin_printf() that only saves the pointer to the format and not the format itself inside the ring buffer. But for a persistent buffer that is read after reboot, the pointers to the format strings may not be the same, or worse, not even exist! Instead, just force the more robust, but slower, version that does the formatting before saving into the ring buffer. The boot mapped buffer can now be used for trace_printk and friends! Using the trace_printk() and the persistent buffer was used to debug the issue with the osnoise tracer: Link: https://lore.kernel.org/all/20240822103443.6a6ae051@gandalf.local.home/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineeth Pillai <vineeth@bitbyteword.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Ross Zwisler <zwisler@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Aring <aahringo@redhat.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Cc: Tomas Glozar <tglozar@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Jonathan Corbet" <corbet@lwn.net> Link: https://lore.kernel.org/20240823014019.386925800@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Steven Rostedt
|
ddb8ea9e5a |
tracing: Allow trace_printk() to go to other instance buffers
Currently, trace_printk() just goes to the top level ring buffer. But there may be times that it should go to one of the instances created by the kernel command line. Add a new trace_instance flag: traceprintk (also can use "printk" or "trace_printk" as people tend to forget the actual flag name). trace_instance=foo^traceprintk Will assign the trace_printk to this buffer at boot up. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineeth Pillai <vineeth@bitbyteword.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Ross Zwisler <zwisler@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Aring <aahringo@redhat.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Cc: Tomas Glozar <tglozar@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Jonathan Corbet" <corbet@lwn.net> Link: https://lore.kernel.org/20240823014019.226694946@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Steven Rostedt
|
b6fc31b687 |
tracing: Add "traceoff" flag to boot time tracing instances
Add a "flags" delimiter (^) to the "trace_instance" kernel command line parameter, and add the "traceoff" flag. The format is: trace_instance=<name>[^<flag1>[^<flag2>]][@<memory>][,<events>] The code allows for more than one flag to be added, but currently only "traceoff" is done so. The motivation for this change came from debugging with the persistent ring buffer and having trace_printk() writing to it. The trace_printk calls are always enabled, and the boot after the crash was having the unwanted trace_printks from the current boot inject into the ring buffer with the trace_printks of the crash kernel, making the output very confusing. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineeth Pillai <vineeth@bitbyteword.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Ross Zwisler <zwisler@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Aring <aahringo@redhat.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Cc: Tomas Glozar <tglozar@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Jonathan Corbet" <corbet@lwn.net> Link: https://lore.kernel.org/20240823014019.053229958@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Vincent Donnefort
|
eb2dcde9f9 |
ring-buffer: Align meta-page to sub-buffers for improved TLB usage
Previously, the mapped ring-buffer layout caused misalignment between the meta-page and sub-buffers when the sub-buffer size was not a multiple of PAGE_SIZE. This prevented hardware with larger TLB entries from utilizing them effectively. Add a padding with the zero-page between the meta-page and sub-buffers. Also update the ring-buffer map_test to verify that padding. Link: https://lore.kernel.org/20240628104611.1443542-1-vdonnefort@google.com Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
d0f2d6e951 |
ring-buffer: Add magic and struct size to boot up meta data
Add a magic number as well as save the struct size of the ring_buffer_meta structure in the meta data to also use as validation. Updating the magic number could be used to force a invalidation between kernel versions, and saving the structure size is also a good method to make sure the content is what is expected. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/20240815115032.0c197b32@rorschach.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |