- 19 Mar, 2023 8 commits
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Costa Shulyupin authored
There is a problem with the behavior of hwlat in a container, resulting in incorrect output. A warning message is generated: "cpumask changed while in round-robin mode, switching to mode none", and the tracing_cpumask is ignored. This issue arises because the kernel thread, hwlatd, is not a part of the container, and the function sched_setaffinity is unable to locate it using its PID. Additionally, the task_struct of hwlatd is already known. Ultimately, the function set_cpus_allowed_ptr achieves the same outcome as sched_setaffinity, but employs task_struct instead of PID. Test case: # cd /sys/kernel/tracing # echo 0 > tracing_on # echo round-robin > hwlat_detector/mode # echo hwlat > current_tracer # unshare --fork --pid bash -c 'echo 1 > tracing_on' # dmesg -c Actual behavior: [573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 0330f7aa ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by:
Costa Shulyupin <costa.shul@redhat.com> Acked-by:
Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Vlastimil Babka authored
The comment refers to mm/slob.c which is being removed. It comes from commit ed56829c ("ring_buffer: reset buffer page when freeing") and according to Steven the borrowed code was a page mapcount and mapping reset, which was later removed by commit e4c2ce82 ("ring_buffer: allocate buffer page pointer"). Thus the comment is not accurate anyway, remove it. Link: https://lore.kernel.org/linux-trace-kernel/20230315142446.27040-1-vbabka@suse.cz Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Reported-by:
Mike Rapoport <mike.rapoport@gmail.com> Suggested-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
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Sung-hun Kim authored
Since the commit 36e2c742 ("fs: don't allow splice read/write without explicit ops") is applied to the kernel, splice() and sendfile() calls on the trace file (/sys/kernel/debug/tracing /trace) return EINVAL. This patch restores these system calls by initializing splice_read in file_operations of the trace file. This patch only enables such functionalities for the read case. Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com Cc: stable@vger.kernel.org Fixes: 36e2c742 ("fs: don't allow splice read/write without explicit ops") Signed-off-by:
Sung-hun Kim <sfoon.kim@samsung.com> Signed-off-by:
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Tom Rix authored
smatch reports this warning kernel/trace/ftrace.c:2594:19: warning: symbol 'direct_ops' was not declared. Should it be static? The variable direct_ops is only used in ftrace.c, so it should be static Link: https://lore.kernel.org/linux-trace-kernel/20230311135113.711824-1-trix@redhat.comSigned-off-by:
Tom Rix <trix@redhat.com> Acked-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
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Tero Kristo authored
The hwlatd tracer will end up starting multiple per-cpu threads with the following script: #!/bin/sh cd /sys/kernel/debug/tracing echo 0 > tracing_on echo hwlat > current_tracer echo per-cpu > hwlat_detector/mode echo 100000 > hwlat_detector/width echo 200000 > hwlat_detector/window echo 1 > tracing_on To fix the issue, check if the hwlatd thread for the cpu is already running, before starting a new one. Along with the previous patch, this avoids running multiple instances of the same CPU thread on the system. Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/ Link: https://lkml.kernel.org/r/20230310100451.3948583-3-tero.kristo@linux.intel.com Cc: stable@vger.kernel.org Fixes: f46b1652 ("trace/hwlat: Implement the per-cpu mode") Signed-off-by:Tero Kristo <tero.kristo@linux.intel.com> Acked-by:
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Tero Kristo authored
Do not wipe the contents of the per-cpu kthread data when starting the tracer, as this will completely forget about already running instances and can later start new additional per-cpu threads. Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/ Link: https://lkml.kernel.org/r/20230310100451.3948583-2-tero.kristo@linux.intel.com Cc: stable@vger.kernel.org Fixes: f46b1652 ("trace/hwlat: Implement the per-cpu mode") Signed-off-by:
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Tom Rix authored
smatch reports several similar warnings kernel/trace/trace_osnoise.c:220:1: warning: symbol '__pcpu_scope_per_cpu_osnoise_var' was not declared. Should it be static? kernel/trace/trace_osnoise.c:243:1: warning: symbol '__pcpu_scope_per_cpu_timerlat_var' was not declared. Should it be static? kernel/trace/trace_osnoise.c:335:14: warning: symbol 'interface_lock' was not declared. Should it be static? kernel/trace/trace_osnoise.c:2242:5: warning: symbol 'timerlat_min_period' was not declared. Should it be static? kernel/trace/trace_osnoise.c:2243:5: warning: symbol 'timerlat_max_period' was not declared. Should it be static? These variables are only used in trace_osnoise.c, so it should be static Link: https://lore.kernel.org/linux-trace-kernel/20230309150414.4036764-1-trix@redhat.comSigned-off-by:
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Anton Gusev authored
Overwriting the error code with the deletion result may cause the function to return 0 despite encountering an error. Commit b111545d ("tracing: Remove the useless value assignment in test_create_synth_event()") solves a similar issue by returning the original error code, so this patch does the same. Found by Linux Verification Center (linuxtesting.org) with SVACE. Link: https://lore.kernel.org/linux-trace-kernel/20230131075818.5322-1-aagusev@ispras.ruSigned-off-by:
Anton Gusev <aagusev@ispras.ru> Reviewed-by:
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- 14 Mar, 2023 1 commit
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Steven Rostedt (Google) authored
A while ago where the trace events had the following: rcu_read_lock_sched_notrace(); rcu_dereference_sched(...); rcu_read_unlock_sched_notrace(); If the tracepoint is enabled, it could trigger RCU issues if called in the wrong place. And this warning was only triggered if lockdep was enabled. If the tracepoint was never enabled with lockdep, the bug would not be caught. To handle this, the above sequence was done when lockdep was enabled regardless if the tracepoint was enabled or not (although the always enabled code really didn't do anything, it would still trigger a warning). But a lot has changed since that lockdep code was added. One is, that sequence no longer triggers any warning. Another is, the tracepoint when enabled doesn't even do that sequence anymore. The main check we care about today is whether RCU is "watching" or not. So if lockdep is enabled, always check if rcu_is_watching() which will trigger a warning if it is not (tracepoints require RCU to be watching). Note, that old sequence did add a bit of overhead when lockdep was enabled, and with the latest kernel updates, would cause the system to slow down enough to trigger kernel "stalled" warnings. Link: http://lore.kernel.org/lkml/20140806181801.GA4605@redhat.com Link: http://lore.kernel.org/lkml/20140807175204.C257CAC5@viggo.jf.intel.com Link: https://lore.kernel.org/lkml/20230307184645.521db5c9@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20230310172856.77406446@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Joel Fernandes <joel@joelfernandes.org> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
Paul E. McKenney <paulmck@kernel.org> Fixes: e6753f23 ("tracepoint: Make rcuidle tracepoint callers use SRCU") Signed-off-by:
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- 10 Mar, 2023 4 commits
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Arnd Bergmann authored
When CONFIG_FUNCTION_GRAPH_TRACER is disabled, __kcfi_typeid_ftrace_stub_graph is missing, causing a link failure: ld.lld: error: undefined symbol: __kcfi_typeid_ftrace_stub_graph referenced by arch/x86/kernel/ftrace_64.o:(__cfi_ftrace_stub_graph) in archive vmlinux.a Mark the reference to it as conditional on the same symbol, as is done on arm64. Link: https://lore.kernel.org/linux-trace-kernel/20230131093643.3850272-1-arnd@kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Fixes: 883bbbff ("ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()") See-also: 2598ac6e ("arm64: ftrace: Define ftrace_stub_graph only with FUNCTION_GRAPH_TRACER") Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Chen Zhongjin authored
KASAN reported follow problem: BUG: KASAN: use-after-free in lookup_rec Read of size 8 at addr ffff000199270ff0 by task modprobe CPU: 2 Comm: modprobe Call trace: kasan_report __asan_load8 lookup_rec ftrace_location arch_check_ftrace_location check_kprobe_address_safe register_kprobe When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a pg which is newly added to ftrace_pages_start in ftrace_process_locs(). Before the first pg->index++, index is 0 and accessing pg->records[-1].ip will cause this problem. Don't check the ip when pg->index is 0. Link: https://lore.kernel.org/linux-trace-kernel/20230309080230.36064-1-chenzhongjin@huawei.com Cc: stable@vger.kernel.org Fixes: 9644302e ("ftrace: Speed up search by skipping pages by address") Suggested-by:
Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by:
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Steven Rostedt (Google) authored
The function hist_field_name() cannot handle being passed a NULL field parameter. It should never be NULL, but due to a previous bug, NULL was passed to the function and the kernel crashed due to a NULL dereference. Mark Rutland reported this to me on IRC. The bug was fixed, but to prevent future bugs from crashing the kernel, check the field and add a WARN_ON() if it is NULL. Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reported-by:
Mark Rutland <mark.rutland@arm.com> Fixes: c6afad49 ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers") Tested-by:
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Steven Rostedt (Google) authored
Histogram values can not be strings, stacktraces, graphs, symbols, syscalls, or grouped in buckets or log. Give an error if a value is set to do so. Note, the histogram code was not prepared to handle these modifiers for histograms and caused a bug. Mark Rutland reported: # echo 'p:copy_to_user __arch_copy_to_user n=$arg2' >> /sys/kernel/tracing/kprobe_events # echo 'hist:keys=n:vals=hitcount.buckets=8:sort=hitcount' > /sys/kernel/tracing/events/kprobes/copy_to_user/trigger # cat /sys/kernel/tracing/events/kprobes/copy_to_user/hist [ 143.694628] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 143.695190] Mem abort info: [ 143.695362] ESR = 0x0000000096000004 [ 143.695604] EC = 0x25: DABT (current EL), IL = 32 bits [ 143.695889] SET = 0, FnV = 0 [ 143.696077] EA = 0, S1PTW = 0 [ 143.696302] FSC = 0x04: level 0 translation fault [ 143.702381] Data abort info: [ 143.702614] ISV = 0, ISS = 0x00000004 [ 143.702832] CM = 0, WnR = 0 [ 143.703087] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000448f9000 [ 143.703407] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 [ 143.704137] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 143.704714] Modules linked in: [ 143.705273] CPU: 0 PID: 133 Comm: cat Not tainted 6.2.0-00003-g6fc512c10a7c #3 [ 143.706138] Hardware name: linux,dummy-virt (DT) [ 143.706723] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 143.707120] pc : hist_field_name.part.0+0x14/0x140 [ 143.707504] lr : hist_field_name.part.0+0x104/0x140 [ 143.707774] sp : ffff800008333a30 [ 143.707952] x29: ffff800008333a30 x28: 0000000000000001 x27: 0000000000400cc0 [ 143.708429] x26: ffffd7a653b20260 x25: 0000000000000000 x24: ffff10d303ee5800 [ 143.708776] x23: ffffd7a6539b27b0 x22: ffff10d303fb8c00 x21: 0000000000000001 [ 143.709127] x20: ffff10d303ec2000 x19: 0000000000000000 x18: 0000000000000000 [ 143.709478] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 143.709824] x14: 0000000000000000 x13: 203a6f666e692072 x12: 6567676972742023 [ 143.710179] x11: 0a230a6d6172676f x10: 000000000000002c x9 : ffffd7a6521e018c [ 143.710584] x8 : 000000000000002c x7 : 7f7f7f7f7f7f7f7f x6 : 000000000000002c [ 143.710915] x5 : ffff10d303b0103e x4 : ffffd7a653b20261 x3 : 000000000000003d [ 143.711239] x2 : 0000000000020001 x1 : 0000000000000001 x0 : 0000000000000000 [ 143.711746] Call trace: [ 143.712115] hist_field_name.part.0+0x14/0x140 [ 143.712642] hist_field_name.part.0+0x104/0x140 [ 143.712925] hist_field_print+0x28/0x140 [ 143.713125] event_hist_trigger_print+0x174/0x4d0 [ 143.713348] hist_show+0xf8/0x980 [ 143.713521] seq_read_iter+0x1bc/0x4b0 [ 143.713711] seq_read+0x8c/0xc4 [ 143.713876] vfs_read+0xc8/0x2a4 [ 143.714043] ksys_read+0x70/0xfc [ 143.714218] __arm64_sys_read+0x24/0x30 [ 143.714400] invoke_syscall+0x50/0x120 [ 143.714587] el0_svc_common.constprop.0+0x4c/0x100 [ 143.714807] do_el0_svc+0x44/0xd0 [ 143.714970] el0_svc+0x2c/0x84 [ 143.715134] el0t_64_sync_handler+0xbc/0x140 [ 143.715334] el0t_64_sync+0x190/0x194 [ 143.715742] Code: a9bd7bfd 910003fd a90153f3 aa0003f3 (f9400000) [ 143.716510] ---[ end trace 0000000000000000 ]--- Segmentation fault Link: https://lkml.kernel.org/r/20230302020810.559462599@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: c6afad49 ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers") Reported-by:
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- 18 Feb, 2023 3 commits
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Wang ShaoBo authored
Remove unnecessary NULL assignment int create_new_subsystem(). Link: https://lkml.kernel.org/r/20221123065124.3982439-1-bobo.shaobowang@huawei.comSigned-off-by:
Wang ShaoBo <bobo.shaobowang@huawei.com> Signed-off-by:
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Jianlin Lv authored
In the case of keeping the system running, the preferred method for tracing the kernel is dynamic tracing (kprobe), but the drawback of this method is that events are lost, especially when tracing packages in the network stack. Livepatching provides a potential solution, which is to reimplement the function you want to replace and insert a static tracepoint. In such a way, custom stable static tracepoints can be expanded without rebooting the system. Link: https://lkml.kernel.org/r/20221102160236.11696-1-iecedge@gmail.comSigned-off-by:
Jianlin Lv <iecedge@gmail.com> Signed-off-by:
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Ross Zwisler authored
The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and Kconfig help messages in the tracing code still refer to this older debugfs path, so let's update them to avoid confusion. Link: https://lore.kernel.org/linux-trace-kernel/20230215223350.2658616-2-zwisler@google.comAcked-by:
Ross Zwisler <zwisler@google.com> Signed-off-by:
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- 16 Feb, 2023 5 commits
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Tom Zanussi authored
Fix a small problem with the histogram specification in the Documentation, and change the example to show output using a stacktrace field rather than the global stacktrace. Link: https://lkml.kernel.org/r/f75f807dd4998249e513515f703a2ff7407605f4.1676063532.git.zanussi@kernel.orgSigned-off-by:
Tom Zanussi <zanussi@kernel.org> Signed-off-by:
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Tom Zanussi authored
The current code will always use the current stacktrace as a key even if a stacktrace contained in a specific event field was specified. For example, we expect to use the 'unsigned long[] stack' field in the below event in the histogram: # echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > /sys/kernel/debug/tracing/dynamic_events # echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger But in fact, when we type out the trigger, we see that it's using the plain old global 'stacktrace' as the key, which is just the stacktrace when the event was hit and not the stacktrace contained in the event, which is what we want: # cat /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active] And in fact, there's no code to actually retrieve it from the event, so we need to add HIST_FIELD_FN_STACK and hist_field_stack() to get it and hook it into the trigger code. For now, since the stack is just using dynamic strings, this could just use the dynamic string function, but it seems cleaner to have a dedicated function an be able to tweak independently as necessary. Link: https://lkml.kernel.org/r/11aa614c82976adbfa4ea763dbe885b5fb01d59c.1676063532.git.zanussi@kernel.orgSigned-off-by:
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Tom Zanussi authored
Currently, there are a few problems when printing hist triggers and trace output when using stacktrace variables. This fixes the problems seen below: # echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger # cat /sys/kernel/debug/tracing/events/synthetic/block_lat/trigger hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active] # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace if prev_state == 2' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger # cat /sys/kernel/debug/tracing/events/sched/sched_switch/trigger hist:keys=next_pid:vals=hitcount:ts=common_timestamp.usecs,st=stacktrace.stacktrace:sort=hitcount:size=2048:clock=global if prev_state == 2 [active] and also in the trace output (should be stack.stacktrace): { delta: ~ 100-199, stacktrace __schedule+0xa19/0x1520 Link: https://lkml.kernel.org/r/60bebd4e546728e012a7a2bcbf58716d48ba6edb.1676063532.git.zanussi@kernel.orgSigned-off-by: -
Steven Rostedt (Google) authored
The max string length for a histogram variable is 256 bytes. The max depth of a stacktrace is 16. With 8byte words, that's 16 * 8 = 128. Which can easily fit in the string variable. The histogram stacktrace is being stored in the string value (with the given max length), with the assumption it will fit. To make sure that this is always the case (in the case that the stack trace depth increases), add a BUILD_BUG_ON() to test this. Link: https://lore.kernel.org/linux-trace-kernel/20230214002418.0103b9e765d3e5c374d2aa7d@kernel.org/Signed-off-by:
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Tom Zanussi authored
Because stacktraces are saved in dynamic strings, trace_event_raw_event_synth() uses strlen to determine the length of the stack. Stacktraces may contain 0-bytes, though, in the saved addresses, so the length found and passed to reserve() will be too small. Fix this by using the first unsigned long in the stack variables to store the actual number of elements in the stack and have trace_event_raw_event_synth() use that to determine the length of the stack. Link: https://lkml.kernel.org/r/1ed6906cd9d6477ef2bd8e63c61de20a9ffe64d7.1676063532.git.zanussi@kernel.orgSigned-off-by:
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- 07 Feb, 2023 11 commits
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Steven Rostedt (Google) authored
Add to ftrace_boot_snapshot, "=<instance>" name, where the instance will get a snapshot buffer, and will take a snapshot at the end of boot (which will save the boot traces). Link: https://lkml.kernel.org/r/20230207173026.792774721@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
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Steven Rostedt (Google) authored
Add a generic trace_array_puts() that can be used to "trace_puts()" into an allocated trace_array instance. This is just another variant of trace_array_printk(). Link: https://lkml.kernel.org/r/20230207173026.584717290@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
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Steven Rostedt (Google) authored
Add the format of: trace_instance=foo,sched:sched_switch,irq_handler_entry,initcall That will create the "foo" instance and enable the sched_switch event (here were the "sched" system is explicitly specified), the irq_handler_entry event, and all events under the system initcall. Link: https://lkml.kernel.org/r/20230207173026.386114535@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
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Steven Rostedt (Google) authored
Add kernel command line to add tracing instances. This only creates instances at boot but still does not enable any events to them. Later changes will extend this command line to add enabling of events, filters, and triggers. As well as possibly redirecting trace_printk()! Link: https://lkml.kernel.org/r/20230207173026.186210158@goodmis.org Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
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Steven Rostedt (Google) authored
The test to check if the field is a stack is to be done if it is not a string. But the code had: } if (event->fields[i]->is_stack) { and not } else if (event->fields[i]->is_stack) { which would cause it to always be tested. Worse yet, this also included an "else" statement that was only to be called if the field was not a string and a stack, but this code allows it to be called if it was a string (and not a stack). Also fixed some whitespace issues. Link: https://lore.kernel.org/all/202301302110.mEtNwkBD-lkp@intel.com/ Link: https://lore.kernel.org/linux-trace-kernel/20230131095237.63e3ca8d@gandalf.local.home Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 00cf3d67 ("tracing: Allow synthetic events to pass around stacktraces") Reported-by:kernel test robot <lkp@intel.com> Signed-off-by:
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Tom Rix authored
smatch reports this representative issue samples/ftrace/ftrace-ops.c:15:14: warning: symbol 'nr_function_calls' was not declared. Should it be static? The nr_functions_calls and several other global variables are only used in ftrace-ops.c, so they should be static. Remove the instances of initializing static int to 0. Link: https://lore.kernel.org/linux-trace-kernel/20230130193708.1378108-1-trix@redhat.comSigned-off-by:
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Arnd Bergmann authored
Calculating the average period requires a 64-bit division that leads to a link failure on 32-bit architectures: x86_64-linux-ld: samples/ftrace/ftrace-ops.o: in function `ftrace_ops_sample_init': ftrace-ops.c:(.init.text+0x23b): undefined reference to `__udivdi3' Use the div_u64() helper to do this instead. Since this is an init function that is not called frequently, the runtime overhead is going to be acceptable. Link: https://lore.kernel.org/linux-trace-kernel/20230130130246.247537-1-arnd@kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: b56c68f7 ("ftrace: Add sample with custom ops") Signed-off-by:
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Song Shuai authored
When other architectures without the nospec functionality write their direct-call functions of samples/ftrace/*.c, the including of asm/nospec-branch.h must be taken care to fix the no header file found error in building process. This commit (ee3e2469 "x86/ftrace: Make it call depth tracking aware") file-globally includes asm/nospec-branch.h providing CALL_DEPTH_ACCOUNT for only x86 direct-call functions. It seems better to move the including to `#ifdef CONFIG_X86_64`. Link: https://lore.kernel.org/linux-trace-kernel/20230130085954.647845-1-suagrfillet@gmail.comSigned-off-by:
Song Shuai <suagrfillet@gmail.com> Reviewed-by:
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Linyu Yuan authored
there is one dwc3 trace event declare as below, DECLARE_EVENT_CLASS(dwc3_log_event, TP_PROTO(u32 event, struct dwc3 *dwc), TP_ARGS(event, dwc), TP_STRUCT__entry( __field(u32, event) __field(u32, ep0state) __dynamic_array(char, str, DWC3_MSG_MAX) ), TP_fast_assign( __entry->event = event; __entry->ep0state = dwc->ep0state; ), TP_printk("event (%08x): %s", __entry->event, dwc3_decode_event(__get_str(str), DWC3_MSG_MAX, __entry->event, __entry->ep0state)) ); the problem is when trace function called, it will allocate up to DWC3_MSG_MAX bytes from trace event buffer, but never fill the buffer during fast assignment, it only fill the buffer when output function are called, so this means if output function are not called, the buffer will never used. add __get_buf(len) which acquiree buffer from iter->tmp_seq when trace output function called, it allow user write string to acquired buffer. the mentioned dwc3 trace event will changed as below, DECLARE_EVENT_CLASS(dwc3_log_event, TP_PROTO(u32 event, struct dwc3 *dwc), TP_ARGS(event, dwc), TP_STRUCT__entry( __field(u32, event) __field(u32, ep0state) ), TP_fast_assign( __entry->event = event; __entry->ep0state = dwc->ep0state; ), TP_printk("event (%08x): %s", __entry->event, dwc3_decode_event(__get_buf(DWC3_MSG_MAX), DWC3_MSG_MAX, __entry->event, __entry->ep0state)) );. Link: https://lore.kernel.org/linux-trace-kernel/1675065249-23368-1-git-send-email-quic_linyyuan@quicinc.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:Linyu Yuan <quic_linyyuan@quicinc.com> Signed-off-by:
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Bagas Sanjaya authored
Most shell command snippets (echo/cat) and their output are already in literal code blocks. However a few still isn't wrapped, in which the htmldocs output is ugly. Wrap the remaining unwrapped snippets, while also fix recent kernel test robot warnings. Link: https://lore.kernel.org/linux-trace-kernel/20230129031402.47420-1-bagasdotme@gmail.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/linux-doc/202301290253.LU5yIxcJ-lkp@intel.com/ Fixes: 88238513 ("tracing/histogram: Document variable stacktrace") Reported-by:
Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by:
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Davidlohr Bueso authored
No slack time is being passed, just use schedule_hrtimeout(). Link: https://lore.kernel.org/linux-trace-kernel/20230123234649.17968-1-dave@stgolabs.netSigned-off-by:
Davidlohr Bueso <dave@stgolabs.net> Acked-by:
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- 25 Jan, 2023 8 commits
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Steven Rostedt (Google) authored
The bpf events are created by the same macro magic as tracefs trace events are. But to hook into bpf, it has its own code. It duplicates many of the same macros as the tracefs macros and this is an issue because it misses bug fixes as well as any new enhancements that come with the other trace macros. As the trace macros have been put into their own staging files, have bpf take advantage of this and use the tracefs stage 6 macros that the "fast ssign" portion of the trace event macro uses. Link: https://lkml.kernel.org/r/20230124202515.873075730@goodmis.org Link: https://lore.kernel.org/lkml/1671181385-5719-1-git-send-email-quic_linyyuan@quicinc.com/ Cc: bpf@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by:
Alexei Starovoitov <ast@kernel.org> Reported-by:
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Steven Rostedt (Google) authored
The perf events are created by the same macro magic as tracefs trace events are. But to hook into perf, it has its own code. It duplicates many of the same macros as the tracefs macros and this is an issue because it misses bug fixes as well as any new enhancements that come with the other trace macros. As the trace macros have been put into their own staging files, have perf take advantage of this and use the tracefs stage 6 macros that the "fast assign" portion of the trace event macro uses. Link: https://lkml.kernel.org/r/20230124202515.716458410@goodmis.org Link: https://lore.kernel.org/lkml/1671181385-5719-1-git-send-email-quic_linyyuan@quicinc.com/ Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by:
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Steven Rostedt (Google) authored
Update the selftests to include a test of passing a stacktrace between the events of a synthetic event. Link: https://lkml.kernel.org/r/20230117152236.475439286@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ross Zwisler <zwisler@google.com> Cc: Ching-lin Yu <chinglinyu@google.com> Signed-off-by:
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Steven Rostedt (Google) authored
Add a little documentation (and a useful example) of how a stacktrace can be used within a histogram variable and synthetic event. Link: https://lkml.kernel.org/r/20230117152236.320181354@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ross Zwisler <zwisler@google.com> Cc: Ching-lin Yu <chinglinyu@google.com> Signed-off-by:
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Steven Rostedt (Google) authored
Now that stacktraces can be part of synthetic events, allow a key to be typed as a stacktrace. # cd /sys/kernel/tracing # echo 's:block_lat u64 delta; unsigned long stack[];' >> dynamic_events # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace if prev_state == 2' >> events/sched/sched_switch/trigger # echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,st2=$st:onmatch(sched.sched_switch).trace(block_lat,$delta,$st2)' >> events/sched/sched_switch/trigger # echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger # cat events/synthetic/block_lat/hist # event histogram # # trigger info: hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active] # { delta: ~ 0-99, stacktrace: event_hist_trigger+0x464/0x480 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x193/0x250 trace_event_raw_event_sched_switch+0xfc/0x150 __traceiter_sched_switch+0x41/0x60 __schedule+0x448/0x7b0 schedule_idle+0x26/0x40 cpu_startup_entry+0x19/0x20 start_secondary+0xed/0xf0 secondary_startup_64_no_verify+0xe0/0xeb } hitcount: 6 { delta: ~ 0-99, stacktrace: event_hist_trigger+0x464/0x480 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x193/0x250 trace_event_raw_event_sched_switch+0xfc/0x150 __traceiter_sched_switch+0x41/0x60 __schedule+0x448/0x7b0 schedule_idle+0x26/0x40 cpu_startup_entry+0x19/0x20 __pfx_kernel_init+0x0/0x10 arch_call_rest_init+0xa/0x24 start_kernel+0x964/0x98d secondary_startup_64_no_verify+0xe0/0xeb } hitcount: 3 { delta: ~ 0-99, stacktrace: event_hist_trigger+0x464/0x480 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x193/0x250 trace_event_raw_event_sched_switch+0xfc/0x150 __traceiter_sched_switch+0x41/0x60 __schedule+0x448/0x7b0 schedule+0x5a/0xb0 worker_thread+0xaf/0x380 kthread+0xe9/0x110 ret_from_fork+0x2c/0x50 } hitcount: 1 { delta: ~ 100-199, stacktrace: event_hist_trigger+0x464/0x480 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x193/0x250 trace_event_raw_event_sched_switch+0xfc/0x150 __traceiter_sched_switch+0x41/0x60 __schedule+0x448/0x7b0 schedule_idle+0x26/0x40 cpu_startup_entry+0x19/0x20 start_secondary+0xed/0xf0 secondary_startup_64_no_verify+0xe0/0xeb } hitcount: 15 [..] { delta: ~ 8500-8599, stacktrace: event_hist_trigger+0x464/0x480 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x193/0x250 trace_event_raw_event_sched_switch+0xfc/0x150 __traceiter_sched_switch+0x41/0x60 __schedule+0x448/0x7b0 schedule_idle+0x26/0x40 cpu_startup_entry+0x19/0x20 start_secondary+0xed/0xf0 secondary_startup_64_no_verify+0xe0/0xeb } hitcount: 1 Totals: Hits: 89 Entries: 11 Dropped: 0 Link: https://lkml.kernel.org/r/20230117152236.167046397@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ross Zwisler <zwisler@google.com> Cc: Ching-lin Yu <chinglinyu@google.com> Signed-off-by: -
Steven Rostedt (Google) authored
Allow a stacktrace from one event to be displayed by the end event of a synthetic event. This is very useful when looking for the longest latency of a sleep or something blocked on I/O. # cd /sys/kernel/tracing/ # echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=stacktrace if prev_state == 1||prev_state == 2' > events/sched/sched_switch/trigger # echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(block_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger The above creates a "block_lat" synthetic event that take the stacktrace of when a task schedules out in either the interruptible or uninterruptible states, and on a new per process max $delta (the time it was scheduled out), will print the process id and the stacktrace. # echo 1 > events/synthetic/block_lat/enable # cat trace # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | kworker/u16:0-767 [006] d..4. 560.645045: block_lat: pid=767 delta=66 stack=STACK: => __schedule => schedule => pipe_read => vfs_read => ksys_read => do_syscall_64 => 0x966000aa <idle>-0 [003] d..4. 561.132117: block_lat: pid=0 delta=413787 stack=STACK: => __schedule => schedule => schedule_hrtimeout_range_clock => do_sys_poll => __x64_sys_poll => do_syscall_64 => 0x966000aa <...>-153 [006] d..4. 562.068407: block_lat: pid=153 delta=54 stack=STACK: => __schedule => schedule => io_schedule => rq_qos_wait => wbt_wait => __rq_qos_throttle => blk_mq_submit_bio => submit_bio_noacct_nocheck => ext4_bio_write_page => mpage_submit_page => mpage_process_page_bufs => mpage_prepare_extent_to_map => ext4_do_writepages => ext4_writepages => do_writepages => __writeback_single_inode Link: https://lkml.kernel.org/r/20230117152236.010941267@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ross Zwisler <zwisler@google.com> Cc: Ching-lin Yu <chinglinyu@google.com> Signed-off-by: -
Steven Rostedt (Google) authored
Allow to save stacktraces into a histogram variable. This will be used by synthetic events to allow a stacktrace from one event to be passed and displayed by another event. The special keyword "stacktrace" is to be used to trigger a stack trace for the event that the histogram trigger is attached to. echo 'hist:keys=pid:st=stacktrace" > events/sched/sched_waking/trigger Currently nothing can get access to the "$st" variable above that contains the stack trace, but that will soon change. Link: https://lkml.kernel.org/r/20230117152235.856323729@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ross Zwisler <zwisler@google.com> Cc: Ching-lin Yu <chinglinyu@google.com> Signed-off-by:
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Steven Rostedt (Google) authored
When tracing a dynamic string field for a synthetic event, the offset calculation for where to write the next event can use struct_size() to find what the current size of the structure is. This simplifies the code and makes it less error prone. Link: https://lkml.kernel.org/r/20230117152235.698632147@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ross Zwisler <zwisler@google.com> Cc: Ching-lin Yu <chinglinyu@google.com> Signed-off-by:
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