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* tracing/osnoise: Fix possible recursive locking in stop_per_cpu_kthreadsNico Pache2022-10-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 99ee9317a1305cd5626736785c8cb38b0e47686c ] There is a recursive lock on the cpu_hotplug_lock. In kernel/trace/trace_osnoise.c:<start/stop>_per_cpu_kthreads: - start_per_cpu_kthreads calls cpus_read_lock() and if start_kthreads returns a error it will call stop_per_cpu_kthreads. - stop_per_cpu_kthreads then calls cpus_read_lock() again causing deadlock. Fix this by calling cpus_read_unlock() before calling stop_per_cpu_kthreads. This behavior can also be seen in commit f46b16520a08 ("trace/hwlat: Implement the per-cpu mode"). This error was noticed during the LTP ftrace-stress-test: WARNING: possible recursive locking detected -------------------------------------------- sh/275006 is trying to acquire lock: ffffffffb02f5400 (cpu_hotplug_lock){++++}-{0:0}, at: stop_per_cpu_kthreads but task is already holding lock: ffffffffb02f5400 (cpu_hotplug_lock){++++}-{0:0}, at: start_per_cpu_kthreads other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(cpu_hotplug_lock); lock(cpu_hotplug_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by sh/275006: #0: ffff8881023f0470 (sb_writers#24){.+.+}-{0:0}, at: ksys_write #1: ffffffffb084f430 (trace_types_lock){+.+.}-{3:3}, at: rb_simple_write #2: ffffffffb02f5400 (cpu_hotplug_lock){++++}-{0:0}, at: start_per_cpu_kthreads Link: https://lkml.kernel.org/r/20220919144932.3064014-1-npache@redhat.com Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations") Signed-off-by: Nico Pache <npache@redhat.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: kprobe: Make gen test module work in arm and riscvYipeng Zou2022-10-261-4/+43
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d8ef45d66c01425ff748e13ef7dd1da7a91cc93c ] For now, this selftest module can only work in x86 because of the kprobe cmd was fixed use of x86 registers. This patch adapted to register names under arm and riscv, So that this module can be worked on those platform. Link: https://lkml.kernel.org/r/20220919125629.238242-3-zouyipeng@huawei.com Cc: <linux-riscv@lists.infradead.org> Cc: <mingo@redhat.com> Cc: <paul.walmsley@sifive.com> Cc: <palmer@dabbelt.com> Cc: <aou@eecs.berkeley.edu> Cc: <zanussi@kernel.org> Cc: <liaochang1@huawei.com> Cc: <chris.zjh@huawei.com> Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Yipeng Zou <zouyipeng@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: kprobe: Fix kprobe event gen test module on exitYipeng Zou2022-10-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ac48e189527fae87253ef2bf58892e782fb36874 ] Correct gen_kretprobe_test clr event para on module exit. This will make it can't to delete. Link: https://lkml.kernel.org/r/20220919125629.238242-2-zouyipeng@huawei.com Cc: <linux-riscv@lists.infradead.org> Cc: <mingo@redhat.com> Cc: <paul.walmsley@sifive.com> Cc: <palmer@dabbelt.com> Cc: <aou@eecs.berkeley.edu> Cc: <zanussi@kernel.org> Cc: <liaochang1@huawei.com> Cc: <chris.zjh@huawei.com> Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Yipeng Zou <zouyipeng@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Fix reading strings from synthetic eventsSteven Rostedt (Google)2022-10-261-6/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0934ae9977c27133449b6dd8c6213970e7eece38 upstream. The follow commands caused a crash: # cd /sys/kernel/tracing # echo 's:open char file[]' > dynamic_events # echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger' # echo 1 > events/synthetic/open/enable BOOM! The problem is that the synthetic event field "char file[]" will read the value given to it as a string without any memory checks to make sure the address is valid. The above example will pass in the user space address and the sythetic event code will happily call strlen() on it and then strscpy() where either one will cause an oops when accessing user space addresses. Use the helper functions from trace_kprobe and trace_eprobe that can read strings safely (and actually succeed when the address is from user space and the memory is mapped in). Now the above can show: packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr Link: https://lkml.kernel.org/r/20221012104534.826549315@goodmis.org Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Add "(fault)" name injection to kernel probesSteven Rostedt (Google)2022-10-261-6/+25
| | | | | | | | | | | | | | | | | | | | | commit 2e9906f84fc7c99388bb7123ade167250d50f1c0 upstream. Have the specific functions for kernel probes that read strings to inject the "(fault)" name directly. trace_probes.c does this too (for uprobes) but as the code to read strings are going to be used by synthetic events (and perhaps other utilities), it simplifies the code by making sure those other uses do not need to implement the "(fault)" name injection as well. Link: https://lkml.kernel.org/r/20221012104534.644803645@goodmis.org Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Move duplicate code of trace_kprobe/eprobe.c into headerSteven Rostedt (Google)2022-10-263-110/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f1d3cbfaafc10464550c6d3a125f4fc802bbaed5 upstream. The functions: fetch_store_strlen_user() fetch_store_strlen() fetch_store_string_user() fetch_store_string() are identical in both trace_kprobe.c and trace_eprobe.c. Move them into a new header file trace_probe_kernel.h to share it. This code will later be used by the synthetic events as well. Marked for stable as a fix for a crash in synthetic events requires it. Link: https://lkml.kernel.org/r/20221012104534.467668078@goodmis.org Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Add ioctl() to force ring buffer waiters to wake upSteven Rostedt (Google)2022-10-261-0/+22
| | | | | | | | | | | | | | | | | commit 01b2a52171735c6eea80ee2f355f32bea6c41418 upstream. If a process is waiting on the ring buffer for data, there currently isn't a clean way to force it to wake up. Add an ioctl call that will force any tasks that are waiting on the trace_pipe_raw file to wake up. Link: https://lkml.kernel.org/r/20220929095029.117f913f@gandalf.local.home Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Wake up waiters when tracing is disabledSteven Rostedt (Google)2022-10-261-0/+6
| | | | | | | | | | | | | commit 2b0fd9a59b7990c161fa1cb7b79edb22847c87c2 upstream. When tracing is disabled, there's no reason that waiters should stay waiting, wake them up, otherwise tasks get stuck when they should be flushing the buffers. Cc: stable@vger.kernel.org Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Wake up ring buffer waiters on closing of the fileSteven Rostedt (Google)2022-10-261-0/+15
| | | | | | | | | | | | | | | | | | commit f3ddb74ad0790030c9592229fb14d8c451f4e9a8 upstream. When the file that represents the ring buffer is closed, there may be waiters waiting on more input from the ring buffer. Call ring_buffer_wake_waiters() to wake up any waiters when the file is closed. Link: https://lkml.kernel.org/r/20220927231825.182416969@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Disable interrupt or preemption before acquiring arch_spinlock_tWaiman Long2022-10-261-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c0a581d7126c0bbc96163276f585fd7b4e4d8d0e upstream. It was found that some tracing functions in kernel/trace/trace.c acquire an arch_spinlock_t with preemption and irqs enabled. An example is the tracing_saved_cmdlines_size_read() function which intermittently causes a "BUG: using smp_processor_id() in preemptible" warning when the LTP read_all_proc test is run. That can be problematic in case preemption happens after acquiring the lock. Add the necessary preemption or interrupt disabling code in the appropriate places before acquiring an arch_spinlock_t. The convention here is to disable preemption for trace_cmdline_lock and interupt for max_lock. Link: https://lkml.kernel.org/r/20220922145622.1744826-1-longman@redhat.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: stable@vger.kernel.org Fixes: a35873a0993b ("tracing: Add conditional snapshot") Fixes: 939c7a4f04fc ("tracing: Introduce saved_cmdlines_size file") Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ring-buffer: Fix race between reset page and reading pageSteven Rostedt (Google)2022-10-261-0/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a0fcaaed0c46cf9399d3a2d6e0c87ddb3df0e044 upstream. The ring buffer is broken up into sub buffers (currently of page size). Each sub buffer has a pointer to its "tail" (the last event written to the sub buffer). When a new event is requested, the tail is locally incremented to cover the size of the new event. This is done in a way that there is no need for locking. If the tail goes past the end of the sub buffer, the process of moving to the next sub buffer takes place. After setting the current sub buffer to the next one, the previous one that had the tail go passed the end of the sub buffer needs to be reset back to the original tail location (before the new event was requested) and the rest of the sub buffer needs to be "padded". The race happens when a reader takes control of the sub buffer. As readers do a "swap" of sub buffers from the ring buffer to get exclusive access to the sub buffer, it replaces the "head" sub buffer with an empty sub buffer that goes back into the writable portion of the ring buffer. This swap can happen as soon as the writer moves to the next sub buffer and before it updates the last sub buffer with padding. Because the sub buffer can be released to the reader while the writer is still updating the padding, it is possible for the reader to see the event that goes past the end of the sub buffer. This can cause obvious issues. To fix this, add a few memory barriers so that the reader definitely sees the updates to the sub buffer, and also waits until the writer has put back the "tail" of the sub buffer back to the last event that was written on it. To be paranoid, it will only spin for 1 second, otherwise it will warn and shutdown the ring buffer code. 1 second should be enough as the writer does have preemption disabled. If the writer doesn't move within 1 second (with preemption disabled) something is horribly wrong. No interrupt should last 1 second! Link: https://lore.kernel.org/all/20220830120854.7545-1-jiazi.li@transsion.com/ Link: https://bugzilla.kernel.org/show_bug.cgi?id=216369 Link: https://lkml.kernel.org/r/20220929104909.0650a36c@gandalf.local.home Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: c7b0930857e22 ("ring-buffer: prevent adding write in discarded area") Reported-by: Jiazi.Li <jiazi.li@transsion.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ring-buffer: Add ring_buffer_wake_waiters()Steven Rostedt (Google)2022-10-261-0/+39
| | | | | | | | | | | | | | | | | | | | commit 7e9fbbb1b776d8d7969551565bc246f74ec53b27 upstream. On closing of a file that represents a ring buffer or flushing the file, there may be waiters on the ring buffer that needs to be woken up and exit the ring_buffer_wait() function. Add ring_buffer_wake_waiters() to wake up the waiters on the ring buffer and allow them to exit the wait loop. Link: https://lkml.kernel.org/r/20220928133938.28dc2c27@gandalf.local.home Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ring-buffer: Check pending waiters when doing wake ups as wellSteven Rostedt (Google)2022-10-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | commit ec0bbc5ec5664dcee344f79373852117dc672c86 upstream. The wake up waiters only checks the "wakeup_full" variable and not the "full_waiters_pending". The full_waiters_pending is set when a waiter is added to the wait queue. The wakeup_full is only set when an event is triggered, and it clears the full_waiters_pending to avoid multiple calls to irq_work_queue(). The irq_work callback really needs to check both wakeup_full as well as full_waiters_pending such that this code can be used to wake up waiters when a file is closed that represents the ring buffer and the waiters need to be woken up. Link: https://lkml.kernel.org/r/20220927231824.209460321@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ring-buffer: Have the shortest_full queue be the shortest not longestSteven Rostedt (Google)2022-10-261-1/+1
| | | | | | | | | | | | | | | | | commit 3b19d614b61b93a131f463817e08219c9ce1fee3 upstream. The logic to know when the shortest waiters on the ring buffer should be woken up or not has uses a less than instead of a greater than compare, which causes the shortest_full to actually be the longest. Link: https://lkml.kernel.org/r/20220927231823.718039222@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 2c2b0a78b3739 ("ring-buffer: Add percentage of ring buffer full to wake up reader") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ring-buffer: Allow splice to read previous partially read pagesSteven Rostedt (Google)2022-10-261-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | commit fa8f4a89736b654125fb254b0db753ac68a5fced upstream. If a page is partially read, and then the splice system call is run against the ring buffer, it will always fail to read, no matter how much is in the ring buffer. That's because the code path for a partial read of the page does will fail if the "full" flag is set. The splice system call wants full pages, so if the read of the ring buffer is not yet full, it should return zero, and the splice will block. But if a previous read was done, where the beginning has been consumed, it should still be given to the splice caller if the rest of the page has been written to. This caused the splice command to never consume data in this scenario, and let the ring buffer just fill up and lose events. Link: https://lkml.kernel.org/r/20220927144317.46be6b80@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 8789a9e7df6bf ("ring-buffer: read page interface") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ftrace: Properly unset FTRACE_HASH_FL_MODZheng Yejian2022-10-261-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 0ce0638edf5ec83343302b884fa208179580700a upstream. When executing following commands like what document said, but the log "#### all functions enabled ####" was not shown as expect: 1. Set a 'mod' filter: $ echo 'write*:mod:ext3' > /sys/kernel/tracing/set_ftrace_filter 2. Invert above filter: $ echo '!write*:mod:ext3' >> /sys/kernel/tracing/set_ftrace_filter 3. Read the file: $ cat /sys/kernel/tracing/set_ftrace_filter By some debugging, I found that flag FTRACE_HASH_FL_MOD was not unset after inversion like above step 2 and then result of ftrace_hash_empty() is incorrect. Link: https://lkml.kernel.org/r/20220926152008.2239274-1-zhengyejian1@huawei.com Cc: <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 8c08f0d5c6fb ("ftrace: Have cached module filters be an active filter") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: hold caller_addr to hardirq_{enable,disable}_ipYipeng Zou2022-09-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 54c3931957f6a6194d5972eccc36d052964b2abe ] Currently, The arguments passing to lockdep_hardirqs_{on,off} was fixed in CALLER_ADDR0. The function trace_hardirqs_on_caller should have been intended to use caller_addr to represent the address that caller wants to be traced. For example, lockdep log in riscv showing the last {enabled,disabled} at __trace_hardirqs_{on,off} all the time(if called by): [ 57.853175] hardirqs last enabled at (2519): __trace_hardirqs_on+0xc/0x14 [ 57.853848] hardirqs last disabled at (2520): __trace_hardirqs_off+0xc/0x14 After use trace_hardirqs_xx_caller, we can get more effective information: [ 53.781428] hardirqs last enabled at (2595): restore_all+0xe/0x66 [ 53.782185] hardirqs last disabled at (2596): ret_from_exception+0xa/0x10 Link: https://lkml.kernel.org/r/20220901104515.135162-2-zouyipeng@huawei.com Cc: stable@vger.kernel.org Fixes: c3bc8fd637a96 ("tracing: Centralize preemptirq tracepoints and unify their usage") Signed-off-by: Yipeng Zou <zouyipeng@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lockdep: Fix -Wunused-parameter for _THIS_IP_Nick Desaulniers2022-09-201-2/+2
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 8b023accc8df70e72f7704d29fead7ca914d6837 ] While looking into a bug related to the compiler's handling of addresses of labels, I noticed some uses of _THIS_IP_ seemed unused in lockdep. Drive by cleanup. -Wunused-parameter: kernel/locking/lockdep.c:1383:22: warning: unused parameter 'ip' kernel/locking/lockdep.c:4246:48: warning: unused parameter 'ip' kernel/locking/lockdep.c:4844:19: warning: unused parameter 'ip' Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20220314221909.2027027-1-ndesaulniers@google.com Stable-dep-of: 54c3931957f6 ("tracing: hold caller_addr to hardirq_{enable,disable}_ip") Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Fix to check event_mutex is held while accessing trigger listMasami Hiramatsu (Google)2022-09-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit cecf8e128ec69149fe53c9a7bafa505a4bee25d9 upstream. Since the check_user_trigger() is called outside of RCU read lock, this list_for_each_entry_rcu() caused a suspicious RCU usage warning. # echo hist:keys=pid > events/sched/sched_stat_runtime/trigger # cat events/sched/sched_stat_runtime/trigger [ 43.167032] [ 43.167418] ============================= [ 43.167992] WARNING: suspicious RCU usage [ 43.168567] 5.19.0-rc5-00029-g19ebe4651abf #59 Not tainted [ 43.169283] ----------------------------- [ 43.169863] kernel/trace/trace_events_trigger.c:145 RCU-list traversed in non-reader section!! ... However, this file->triggers list is safe when it is accessed under event_mutex is held. To fix this warning, adds a lockdep_is_held check to the list_for_each_entry_rcu(). Link: https://lkml.kernel.org/r/166226474977.223837.1992182913048377113.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is deadYang Jihong2022-09-051-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c3b0f72e805f0801f05fa2aa52011c4bfc694c44 upstream. ftrace_startup does not remove ops from ftrace_ops_list when ftrace_startup_enable fails: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&ftrace_ops_list, ops) ... ... ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1 ... return 0 // ops is in the ftrace_ops_list. When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything: unregister_ftrace_function ftrace_shutdown if (unlikely(ftrace_disabled)) return -ENODEV; // return here, __unregister_ftrace_function is not executed, // as a result, ops is still in the ftrace_ops_list __unregister_ftrace_function ... If ops is dynamically allocated, it will be free later, in this case, is_ftrace_trampoline accesses NULL pointer: is_ftrace_trampoline ftrace_ops_trampoline do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL! Syzkaller reports as follows: [ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b [ 1203.508039] #PF: supervisor read access in kernel mode [ 1203.508798] #PF: error_code(0x0000) - not-present page [ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0 [ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI [ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8 [ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0 [ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00 [ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246 [ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866 [ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b [ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07 [ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399 [ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008 [ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 [ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0 [ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Therefore, when ftrace_startup_enable fails, we need to rollback registration process and remove ops from ftrace_ops_list. Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/eprobes: Fix reading of string fieldsSteven Rostedt (Google)2022-08-251-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | commit f04dec93466a0481763f3b56cdadf8076e28bfbf upstream. Currently when an event probe (eprobe) hooks to a string field, it does not display it as a string, but instead as a number. This makes the field rather useless. Handle the different kinds of strings, dynamic, static, relational/dynamic etc. Now when a string field is used, the ":string" type can be used to display it: echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Have filter accept "common_cpu" to be consistentSteven Rostedt (Google)2022-08-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | commit b2380577d4fe1c0ef3fa50417f1e441c016e4cbe upstream. Make filtering consistent with histograms. As "cpu" can be a field of an event, allow for "common_cpu" to keep it from being confused with the "cpu" field of the event. Link: https://lkml.kernel.org/r/20220820134401.513062765@goodmis.org Link: https://lore.kernel.org/all/20220820220920.e42fa32b70505b1904f0a0ad@kernel.org/ Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 1e3bac71c5053 ("tracing/histogram: Rename "cpu" to "common_cpu"") Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/probes: Have kprobes and uprobes use $COMM tooSteven Rostedt (Google)2022-08-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | commit ab8384442ee512fc0fc72deeb036110843d0e7ff upstream. Both $comm and $COMM can be used to get current->comm in eprobes and the filtering and histogram logic. Make kprobes and uprobes consistent in this regard and allow both $comm and $COMM as well. Currently kprobes and uprobes only handle $comm, which is inconsistent with the other utilities, and can be confusing to users. Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/ Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/eprobes: Have event probes be consistent with kprobes and uprobesSteven Rostedt (Google)2022-08-251-6/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6a832ec3d680b3a4f4fad5752672827d71bae501 upstream. Currently, if a symbol "@" is attempted to be used with an event probe (eprobes), it will cause a NULL pointer dereference crash. Both kprobes and uprobes can reference data other than the main registers. Such as immediate address, symbols and the current task name. Have eprobes do the same thing. For "comm", if "comm" is used and the event being attached to does not have the "comm" field, then make it the "$comm" that kprobes has. This is consistent to the way histograms and filters work. Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/eprobes: Do not hardcode $comm as a stringSteven Rostedt (Google)2022-08-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | commit 02333de90e5945e2fe7fc75b15b4eb9aee187f0a upstream. The variable $comm is hard coded as a string, which is true for both kprobes and uprobes, but for event probes (eprobes) it is a field name. In most cases the "comm" field would be a string, but there's no guarantee of that fact. Do not assume that comm is a string. Not to mention, it currently forces comm fields to fault, as string processing for event probes is currently broken. Link: https://lkml.kernel.org/r/20220820134400.756152112@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/eprobes: Do not allow eprobes to use $stack, or % for regsSteven Rostedt (Google)2022-08-251-8/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2673c60ee67e71f2ebe34386e62d348f71edee47 upstream. While playing with event probes (eprobes), I tried to see what would happen if I attempted to retrieve the instruction pointer (%rip) knowing that event probes do not use pt_regs. The result was: BUG: kernel NULL pointer dereference, address: 0000000000000024 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:get_event_field.isra.0+0x0/0x50 Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8 50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24 8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74 RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086 RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000 RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8 R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8 R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff916c9ea40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0 Call Trace: <TASK> get_eprobe_size+0xb4/0x640 ? __mod_node_page_state+0x72/0xc0 __eprobe_trace_func+0x59/0x1a0 ? __mod_lruvec_page_state+0xaa/0x1b0 ? page_remove_file_rmap+0x14/0x230 ? page_remove_rmap+0xda/0x170 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x18f/0x240 trace_event_raw_event_sched_wakeup_template+0x7a/0xb0 try_to_wake_up+0x260/0x4c0 __wake_up_common+0x80/0x180 __wake_up_common_lock+0x7c/0xc0 do_notify_parent+0x1c9/0x2a0 exit_notify+0x1a9/0x220 do_exit+0x2ba/0x450 do_group_exit+0x2d/0x90 __x64_sys_exit_group+0x14/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Obviously this is not the desired result. Move the testing for TPARG_FL_TPOINT which is only used for event probes to the top of the "$" variable check, as all the other variables are not used for event probes. Also add a check in the register parsing "%" to fail if an event probe is used. Link: https://lkml.kernel.org/r/20220820134400.564426983@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/perf: Fix double put of trace event when init failsSteven Rostedt (Google)2022-08-251-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7249921d94ff64f67b733eca0b68853a62032b3d upstream. If in perf_trace_event_init(), the perf_trace_event_open() fails, then it will call perf_trace_event_unreg() which will not only unregister the perf trace event, but will also call the put() function of the tp_event. The problem here is that the trace_event_try_get_ref() is called by the caller of perf_trace_event_init() and if perf_trace_event_init() returns a failure, it will then call trace_event_put(). But since the perf_trace_event_unreg() already called the trace_event_put() function, it triggers a WARN_ON(). WARNING: CPU: 1 PID: 30309 at kernel/trace/trace_dynevent.c:46 trace_event_dyn_put_ref+0x15/0x20 If perf_trace_event_reg() does not call the trace_event_try_get_ref() then the perf_trace_event_unreg() should not be calling trace_event_put(). This breaks symmetry and causes bugs like these. Pull out the trace_event_put() from perf_trace_event_unreg() and call it in the locations that perf_trace_event_unreg() is called. This not only fixes this bug, but also brings back the proper symmetry of the reg/unreg vs get/put logic. Link: https://lore.kernel.org/all/cover.1660347763.git.kjlx@templeofstupid.com/ Link: https://lkml.kernel.org/r/20220816192817.43d5e17f@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 1d18538e6a092 ("tracing: Have dynamic events have a ref counter") Reported-by: Krister Johansen <kjlx@templeofstupid.com> Reviewed-by: Krister Johansen <kjlx@templeofstupid.com> Tested-by: Krister Johansen <kjlx@templeofstupid.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Add '__rel_loc' using trace event macrosMasami Hiramatsu2022-08-171-0/+3
| | | | | | | | | | | | | | | | | | [ Upstream commit 55de2c0b5610cba5a5a93c0788031133c457e689 ] Add '__rel_loc' using trace event macros. These macros are usually not used in the kernel, except for testing purpose. This also add "rel_" variant of macros for dynamic_array string, and bitmask. Link: https://lkml.kernel.org/r/163757342119.510314.816029622439099016.stgit@devnote2 Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* blktrace: Trace remapped requests correctlyBart Van Assche2022-08-171-1/+1
| | | | | | | | | | | | | | | | | | | [ Upstream commit 22c80aac882f712897b88b7ea8f5a74ea19019df ] Trace the remapped operation and its flags instead of only the data direction of remapped operations. This issue was detected by analyzing the warnings reported by sparse related to the new blk_opf_t type. Reviewed-by: Jun'ichi Nomura <junichi.nomura@nec.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mike Christie <michael.christie@oracle.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Fixes: 1b9a9ab78b0a ("blktrace: use op accessors") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-11-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Fix return value of trace_pid_write()Wonhyuk Yang2022-07-291-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b27f266f74fbda4ee36c2b2b04d15992860cf23b ] Setting set_event_pid with trailing whitespace lead to endless write system calls like below. $ strace echo "123 " > /sys/kernel/debug/tracing/set_event_pid execve("/usr/bin/echo", ["echo", "123 "], ...) = 0 ... write(1, "123 \n", 5) = 4 write(1, "\n", 1) = 0 write(1, "\n", 1) = 0 write(1, "\n", 1) = 0 write(1, "\n", 1) = 0 write(1, "\n", 1) = 0 .... This is because, the result of trace_get_user's are not returned when it read at least one pid. To fix it, update read variable even if parser->idx == 0. The result of applied patch is below. $ strace echo "123 " > /sys/kernel/debug/tracing/set_event_pid execve("/usr/bin/echo", ["echo", "123 "], ...) = 0 ... write(1, "123 \n", 5) = 5 close(1) = 0 Link: https://lkml.kernel.org/r/20220503050546.288911-1-vvghjk1234@gmail.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Baik Song An <bsahn@etri.re.kr> Cc: Hong Yeon Kim <kimhy@etri.re.kr> Cc: Taeung Song <taeung@reallinux.co.kr> Cc: linuxgeek@linuxgeek.io Cc: stable@vger.kernel.org Fixes: 4909010788640 ("tracing: Add set_event_pid directory for future use") Signed-off-by: Wonhyuk Yang <vvghjk1234@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Place trace_pid_list logic into abstract functionsSteven Rostedt (VMware)2022-07-297-61/+217
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 6954e415264eeb5ee6be0d22d789ad12c995ee64 ] Instead of having the logic that does trace_pid_list open coded, wrap it in abstract functions. This will allow a rewrite of the logic that implements the trace_pid_list without affecting the users. Note, this causes a change in behavior. Every time a pid is written into the set_*_pid file, it creates a new list and uses RCU to update it. If pid_max is lowered, but there was a pid currently in the list that was higher than pid_max, those pids will now be removed on updating the list. The old behavior kept that from happening. The rewrite of the pid_list logic will no longer depend on pid_max, and will return the old behavior. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Have event format check not flag %p* on __get_dynamic_array()Steven Rostedt (Google)2022-07-291-0/+7
| | | | | | | | | | | | | | | | | | [ Upstream commit 499f12168aebd6da8fa32c9b7d6203ca9b5eb88d ] The print fmt check against trace events to make sure that the format does not use pointers that may be freed from the time of the trace to the time the event is read, gives a false positive on %pISpc when reading data that was saved in __get_dynamic_array() when it is perfectly fine to do so, as the data being read is on the ring buffer. Link: https://lore.kernel.org/all/20220407144524.2a592ed6@canb.auug.org.au/ Cc: stable@vger.kernel.org Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Fix sleeping while atomic in kdb ftdumpDouglas Anderson2022-07-211-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 495fcec8648cdfb483b5b9ab310f3839f07cb3b8 ] If you drop into kdb and type "ftdump" you'll get a sleeping while atomic warning from memory allocation in trace_find_next_entry(). This appears to have been caused by commit ff895103a84a ("tracing: Save off entry when peeking at next entry"), which added the allocation in that path. The problematic commit was already fixed by commit 8e99cf91b99b ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic") but that fix missed the kdb case. The fix here is easy: just move the assignment of the static buffer to the place where it should have been to begin with: trace_init_global_iter(). That function is called in two places, once is right before the assignment of the static buffer added by the previous fix and once is in kdb. Note that it appears that there's a second static buffer that we need to assign that was added in commit efbbdaa22bb7 ("tracing: Show real address for trace event arguments"), so we'll move that too. Link: https://lkml.kernel.org/r/20220708170919.1.I75844e5038d9425add2ad853a608cb44bb39df40@changeid Fixes: ff895103a84a ("tracing: Save off entry when peeking at next entry") Fixes: efbbdaa22bb7 ("tracing: Show real address for trace event arguments") Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing/histograms: Fix memory leak problemZheng Yejian2022-07-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7edc3945bdce9c39198a10d6129377a5c53559c2 upstream. This reverts commit 46bbe5c671e06f070428b9be142cc4ee5cedebac. As commit 46bbe5c671e0 ("tracing: fix double free") said, the "double free" problem reported by clang static analyzer is: > In parse_var_defs() if there is a problem allocating > var_defs.expr, the earlier var_defs.name is freed. > This free is duplicated by free_var_defs() which frees > the rest of the list. However, if there is a problem allocating N-th var_defs.expr: + in parse_var_defs(), the freed 'earlier var_defs.name' is actually the N-th var_defs.name; + then in free_var_defs(), the names from 0th to (N-1)-th are freed; IF ALLOCATING PROBLEM HAPPENED HERE!!! -+ \ | 0th 1th (N-1)-th N-th V +-------------+-------------+-----+-------------+----------- var_defs: | name | expr | name | expr | ... | name | expr | name | /// +-------------+-------------+-----+-------------+----------- These two frees don't act on same name, so there was no "double free" problem before. Conversely, after that commit, we get a "memory leak" problem because the above "N-th var_defs.name" is not freed. If enable CONFIG_DEBUG_KMEMLEAK and inject a fault at where the N-th var_defs.expr allocated, then execute on shell like: $ echo 'hist:key=call_site:val=$v1,$v2:v1=bytes_req,v2=bytes_alloc' > \ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger Then kmemleak reports: unreferenced object 0xffff8fb100ef3518 (size 8): comm "bash", pid 196, jiffies 4295681690 (age 28.538s) hex dump (first 8 bytes): 76 31 00 00 b1 8f ff ff v1...... backtrace: [<0000000038fe4895>] kstrdup+0x2d/0x60 [<00000000c99c049a>] event_hist_trigger_parse+0x206f/0x20e0 [<00000000ae70d2cc>] trigger_process_regex+0xc0/0x110 [<0000000066737a4c>] event_trigger_write+0x75/0xd0 [<000000007341e40c>] vfs_write+0xbb/0x2a0 [<0000000087fde4c2>] ksys_write+0x59/0xd0 [<00000000581e9cdf>] do_syscall_64+0x3a/0x80 [<00000000cf3b065c>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 Link: https://lkml.kernel.org/r/20220711014731.69520-1-zhengyejian1@huawei.com Cc: stable@vger.kernel.org Fixes: 46bbe5c671e0 ("tracing: fix double free") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/kprobes: Check whether get_kretprobe() returns NULL in ↵Masami Hiramatsu (Google)2022-06-291-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kretprobe_dispatcher() commit cc72b72073ac982a954d3b43519ca1c28f03c27c upstream. There is a small chance that get_kretprobe(ri) returns NULL in kretprobe_dispatcher() when another CPU unregisters the kretprobe right after __kretprobe_trampoline_handler(). To avoid this issue, kretprobe_dispatcher() checks the get_kretprobe() return value again. And if it is NULL, it returns soon because that kretprobe is under unregistering process. This issue has been introduced when the kretprobe is decoupled from the struct kretprobe_instance by commit d741bf41d7c7 ("kprobes: Remove kretprobe hash"). Before that commit, the struct kretprob_instance::rp directly points the kretprobe and it is never be NULL. Link: https://lkml.kernel.org/r/165366693881.797669.16926184644089588731.stgit@devnote2 Reported-by: Yonghong Song <yhs@fb.com> Fixes: d741bf41d7c7 ("kprobes: Remove kretprobe hash") Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: bpf <bpf@vger.kernel.org> Cc: Kernel Team <kernel-team@fb.com> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Avoid adding tracer option before update_tracer_optionsMark-PK Tsai2022-06-141-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ef9188bcc6ca1d8a2ad83e826b548e6820721061 ] To prepare for support asynchronous tracer_init_tracefs initcall, avoid calling create_trace_option_files before __update_tracer_options. Otherwise, create_trace_option_files will show warning because some tracers in trace_types list are already in tr->topts. For example, hwlat_tracer call register_tracer in late_initcall, and global_trace.dir is already created in tracing_init_dentry, hwlat_tracer will be put into tr->topts. Then if the __update_tracer_options is executed after hwlat_tracer registered, create_trace_option_files find that hwlat_tracer is already in tr->topts. Link: https://lkml.kernel.org/r/20220426122407.17042-2-mark-pk.tsai@mediatek.com Link: https://lore.kernel.org/lkml/20220322133339.GA32582@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Fix sleeping function called from invalid context on RT kernelJun Miao2022-06-141-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 12025abdc8539ed9d5014e2d647a3fd1bd3de5cd ] When setting bootparams="trace_event=initcall:initcall_start tp_printk=1" in the cmdline, the output_printk() was called, and the spin_lock_irqsave() was called in the atomic and irq disable interrupt context suitation. On the PREEMPT_RT kernel, these locks are replaced with sleepable rt-spinlock, so the stack calltrace will be triggered. Fix it by raw_spin_lock_irqsave when PREEMPT_RT and "trace_event=initcall:initcall_start tp_printk=1" enabled. BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 Preemption disabled at: [<ffffffff8992303e>] try_to_wake_up+0x7e/0xba0 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.1-rt17+ #19 34c5812404187a875f32bee7977f7367f9679ea7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x60/0x8c dump_stack+0x10/0x12 __might_resched.cold+0x11d/0x155 rt_spin_lock+0x40/0x70 trace_event_buffer_commit+0x2fa/0x4c0 ? map_vsyscall+0x93/0x93 trace_event_raw_event_initcall_start+0xbe/0x110 ? perf_trace_initcall_finish+0x210/0x210 ? probe_sched_wakeup+0x34/0x40 ? ttwu_do_wakeup+0xda/0x310 ? trace_hardirqs_on+0x35/0x170 ? map_vsyscall+0x93/0x93 do_one_initcall+0x217/0x3c0 ? trace_event_raw_event_initcall_level+0x170/0x170 ? push_cpu_stop+0x400/0x400 ? cblist_init_generic+0x241/0x290 kernel_init_freeable+0x1ac/0x347 ? _raw_spin_unlock_irq+0x65/0x80 ? rest_init+0xf0/0xf0 kernel_init+0x1e/0x150 ret_from_fork+0x22/0x30 </TASK> Link: https://lkml.kernel.org/r/20220419013910.894370-1-jun.miao@intel.com Signed-off-by: Jun Miao <jun.miao@intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Make tp_printk work on syscall tracepointsJeff Xie2022-06-141-24/+11
| | | | | | | | | | | | | | | | | | | | [ Upstream commit cb1c45fb68b8a4285ccf750842b1136f26cfe267 ] Currently the tp_printk option has no effect on syscall tracepoint. When adding the kernel option parameter tp_printk, then: echo 1 > /sys/kernel/debug/tracing/events/syscalls/enable When running any application, no trace information is printed on the terminal. Now added printk for syscall tracepoints. Link: https://lkml.kernel.org/r/20220410145025.681144-1-xiehuan09@gmail.com Signed-off-by: Jeff Xie <xiehuan09@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ftrace: Clean up hash direct_functions on register failuresSong Liu2022-06-091-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7d54c15cb89a29a5f59e5ffc9ee62e6591769ef1 upstream. We see the following GPF when register_ftrace_direct fails: [ ] general protection fault, probably for non-canonical address \ 0x200000000000010: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [...] [ ] RIP: 0010:ftrace_find_rec_direct+0x53/0x70 [ ] Code: 48 c1 e0 03 48 03 42 08 48 8b 10 31 c0 48 85 d2 74 [...] [ ] RSP: 0018:ffffc9000138bc10 EFLAGS: 00010206 [ ] RAX: 0000000000000000 RBX: ffffffff813e0df0 RCX: 000000000000003b [ ] RDX: 0200000000000000 RSI: 000000000000000c RDI: ffffffff813e0df0 [ ] RBP: ffffffffa00a3000 R08: ffffffff81180ce0 R09: 0000000000000001 [ ] R10: ffffc9000138bc18 R11: 0000000000000001 R12: ffffffff813e0df0 [ ] R13: ffffffff813e0df0 R14: ffff888171b56400 R15: 0000000000000000 [ ] FS: 00007fa9420c7780(0000) GS:ffff888ff6a00000(0000) knlGS:000000000 [ ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ ] CR2: 000000000770d000 CR3: 0000000107d50003 CR4: 0000000000370ee0 [ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ ] Call Trace: [ ] <TASK> [ ] register_ftrace_direct+0x54/0x290 [ ] ? render_sigset_t+0xa0/0xa0 [ ] bpf_trampoline_update+0x3f5/0x4a0 [ ] ? 0xffffffffa00a3000 [ ] bpf_trampoline_link_prog+0xa9/0x140 [ ] bpf_tracing_prog_attach+0x1dc/0x450 [ ] bpf_raw_tracepoint_open+0x9a/0x1e0 [ ] ? find_held_lock+0x2d/0x90 [ ] ? lock_release+0x150/0x430 [ ] __sys_bpf+0xbd6/0x2700 [ ] ? lock_is_held_type+0xd8/0x130 [ ] __x64_sys_bpf+0x1c/0x20 [ ] do_syscall_64+0x3a/0x80 [ ] entry_SYSCALL_64_after_hwframe+0x44/0xae [ ] RIP: 0033:0x7fa9421defa9 [ ] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 9 f8 [...] [ ] RSP: 002b:00007ffed743bd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ ] RAX: ffffffffffffffda RBX: 00000000069d2480 RCX: 00007fa9421defa9 [ ] RDX: 0000000000000078 RSI: 00007ffed743bd80 RDI: 0000000000000011 [ ] RBP: 00007ffed743be00 R08: 0000000000bb7270 R09: 0000000000000000 [ ] R10: 00000000069da210 R11: 0000000000000246 R12: 0000000000000001 [ ] R13: 00007ffed743c4b0 R14: 00000000069d2480 R15: 0000000000000001 [ ] </TASK> [ ] Modules linked in: klp_vm(OK) [ ] ---[ end trace 0000000000000000 ]--- One way to trigger this is: 1. load a livepatch that patches kernel function xxx; 2. run bpftrace -e 'kfunc:xxx {}', this will fail (expected for now); 3. repeat #2 => gpf. This is because the entry is added to direct_functions, but not removed. Fix this by remove the entry from direct_functions when register_ftrace_direct fails. Also remove the last trailing space from ftrace.c, so we don't have to worry about it anymore. Link: https://lkml.kernel.org/r/20220524170839.900849-1-song@kernel.org Cc: stable@vger.kernel.org Fixes: 763e34e74bb7 ("ftrace: Add register_ftrace_direct()") Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Initialize integer variable to prevent garbage return valueGautam Menghani2022-06-091-1/+1
| | | | | | | | | | | | | | | | | | commit 154827f8e53d8c492b3fb0cb757fbcadb5d516b5 upstream. Initialize the integer variable to 0 to fix the clang scan warning: Undefined or garbage value returned to caller [core.uninitialized.UndefReturn] return ret; Link: https://lkml.kernel.org/r/20220522061826.1751-1-gautammenghani201@gmail.com Cc: stable@vger.kernel.org Fixes: 8993665abcce ("tracing/boot: Support multiple handlers for per-event histogram") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Fix potential double free in create_var_ref()Keita Suzuki2022-06-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 99696a2592bca641eb88cc9a80c90e591afebd0f upstream. In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref(). Link: https://lkml.kernel.org/r/20220425063739.3859998-1-keitasuzuki.park@sslab.ics.keio.ac.jp Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers") CC: stable@vger.kernel.org Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem.Hao Luo2022-05-011-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | commit 216e3cd2f28dbbf1fe86848e0e29e6693b9f0a20 upstream. Some helper functions may modify its arguments, for example, bpf_d_path, bpf_get_stack etc. Previously, their argument types were marked as ARG_PTR_TO_MEM, which is compatible with read-only mem types, such as PTR_TO_RDONLY_BUF. Therefore it's legitimate, but technically incorrect, to modify a read-only memory by passing it into one of such helper functions. This patch tags the bpf_args compatible with immutable memory with MEM_RDONLY flag. The arguments that don't have this flag will be only compatible with mutable memory types, preventing the helper from modifying a read-only memory. The bpf_args that have MEM_RDONLY are compatible with both mutable memory and immutable memory. Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211217003152.48334-9-haoluo@google.com Cc: stable@vger.kernel.org # 5.15.x Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Have type enum modifications copy the stringsSteven Rostedt (Google)2022-04-081-1/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 795301d3c28996219d555023ac6863401b6076bc upstream. When an enum is used in the visible parts of a trace event that is exported to user space, the user space applications like perf and trace-cmd do not have a way to know what the value of the enum is. To solve this, at boot up (or module load) the printk formats are modified to replace the enum with their numeric value in the string output. Array fields of the event are defined by [<nr-elements>] in the type portion of the format file so that the user space parsers can correctly parse the array into the appropriate size chunks. But in some trace events, an enum is used in defining the size of the array, which once again breaks the parsing of user space tooling. This was solved the same way as the print formats were, but it modified the type strings of the trace event. This caused crashes in some architectures because, as supposed to the print string, is a const string value. This was not detected on x86, as it appears that const strings are still writable (at least in boot up), but other architectures this is not the case, and writing to a const string will cause a kernel fault. To fix this, use kstrdup() to copy the type before modifying it. If the trace event is for the core kernel there's no need to free it because the string will be in use for the life of the machine being on line. For modules, create a link list to store all the strings being allocated for modules and when the module is removed, free them. Link: https://lore.kernel.org/all/yt9dr1706b4i.fsf@linux.ibm.com/ Link: https://lkml.kernel.org/r/20220318153432.3984b871@gandalf.local.home Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Sven Schnelle <svens@linux.ibm.com> Reported-by: Sven Schnelle <svens@linux.ibm.com> Fixes: b3bc8547d3be ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing: Have TRACE_DEFINE_ENUM affect trace event types as wellSteven Rostedt (Google)2022-04-081-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b3bc8547d3be60898818885f5bf22d0a62e2eb48 ] The macro TRACE_DEFINE_ENUM is used to convert enums in the kernel to their actual value when they are exported to user space via the trace event format file. Currently only the enums in the "print fmt" (TP_printk in the TRACE_EVENT macro) have the enums converted. But the enums can be used to denote array size: field:unsigned int fc_ineligible_rc[EXT4_FC_REASON_MAX]; offset:12; size:36; signed:0; The EXT4_FC_REASON_MAX has no meaning to userspace but it needs to know that information to know how to parse the array. Have the array indexes also be parsed as well. Link: https://lore.kernel.org/all/cover.1646922487.git.riteshh@linux.ibm.com/ Reported-by: Ritesh Harjani <riteshh@linux.ibm.com> Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Have trace event string test handle zero length stringsSteven Rostedt (Google)2022-04-081-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | commit eca344a7362e0f34f179298fd8366bcd556eede1 upstream. If a trace event has in its TP_printk(): "%*.s", len, len ? __get_str(string) : NULL It is perfectly valid if len is zero and passing in the NULL. Unfortunately, the runtime string check at time of reading the trace sees the NULL and flags it as a bad string and produces a WARN_ON(). Handle this case by passing into the test function if the format has an asterisk (star) and if so, if the length is zero, then mark it as safe. Link: https://lore.kernel.org/all/YjsWzuw5FbWPrdqq@bfoster/ Cc: stable@vger.kernel.org Reported-by: Brian Foster <bfoster@redhat.com> Tested-by: Brian Foster <bfoster@redhat.com> Fixes: 9a6944fee68e2 ("tracing: Add a verifier to check string pointers for trace events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/osnoise: Force quiescent states while tracingNicolas Saenz Julienne2022-03-161-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit caf4c86bf136845982c5103b2661751b40c474c0 upstream. At the moment running osnoise on a nohz_full CPU or uncontested FIFO priority and a PREEMPT_RCU kernel might have the side effect of extending grace periods too much. This will entice RCU to force a context switch on the wayward CPU to end the grace period, all while introducing unwarranted noise into the tracer. This behaviour is unavoidable as overly extending grace periods might exhaust the system's memory. This same exact problem is what extended quiescent states (EQS) were created for, conversely, rcu_momentary_dyntick_idle() emulates them by performing a zero duration EQS. So let's make use of it. In the common case rcu_momentary_dyntick_idle() is fairly inexpensive: atomically incrementing a local per-CPU counter and doing a store. So it shouldn't affect osnoise's measurements (which has a 1us granularity), so we'll call it unanimously. The uncommon case involve calling rcu_momentary_dyntick_idle() after having the osnoise process: - Receive an expedited quiescent state IPI with preemption disabled or during an RCU critical section. (activates rdp->cpu_no_qs.b.exp code-path). - Being preempted within in an RCU critical section and having the subsequent outermost rcu_read_unlock() called with interrupts disabled. (t->rcu_read_unlock_special.b.blocked code-path). Neither of those are possible at the moment, and are unlikely to be in the future given the osnoise's loop design. On top of this, the noise generated by the situations described above is unavoidable, and if not exposed by rcu_momentary_dyntick_idle() will be eventually seen in subsequent rcu_read_unlock() calls or schedule operations. Link: https://lkml.kernel.org/r/20220307180740.577607-1-nsaenzju@redhat.com Cc: stable@vger.kernel.org Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/osnoise: Make osnoise_main to sleep for microsecondsDaniel Bristot de Oliveira2022-03-161-21/+32
| | | | | | | | | | | | | | | | | | [ Upstream commit dd990352f01ee9a6c6eee152e5d11c021caccfe4 ] osnoise's runtime and period are in the microseconds scale, but it is currently sleeping in the millisecond's scale. This behavior roots in the usage of hwlat as the skeleton for osnoise. Make osnoise to sleep in the microseconds scale. Also, move the sleep to a specialized function. Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Ensure trace buffer is at least 4096 bytes largeSven Schnelle2022-03-161-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 7acf3a127bb7c65ff39099afd78960e77b2ca5de ] Booting the kernel with 'trace_buf_size=1' give a warning at boot during the ftrace selftests: [ 0.892809] Running postponed tracer tests: [ 0.892893] Testing tracer function: [ 0.901899] Callback from call_rcu_tasks_trace() invoked. [ 0.983829] Callback from call_rcu_tasks_rude() invoked. [ 1.072003] .. bad ring buffer .. corrupted trace buffer .. [ 1.091944] Callback from call_rcu_tasks() invoked. [ 1.097695] PASSED [ 1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED! [ 1.353474] ------------[ cut here ]------------ [ 1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0 Therefore enforce a minimum of 4096 bytes to make the selftest pass. Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* tracing: Fix return value of __setup handlersRandy Dunlap2022-03-082-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1d02b444b8d1345ea4708db3bab4db89a7784b55 upstream. __setup() handlers should generally return 1 to indicate that the boot options have been handled. Using invalid option values causes the entire kernel boot option string to be reported as Unknown and added to init's environment strings, polluting it. Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6 kprobe_event=p,syscall_any,$arg1 trace_options=quiet trace_clock=jiffies", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc6 kprobe_event=p,syscall_any,$arg1 trace_options=quiet trace_clock=jiffies Return 1 from the __setup() handlers so that init's environment is not polluted with kernel boot options. Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org Cc: stable@vger.kernel.org Fixes: 7bcfaf54f591 ("tracing: Add trace_options kernel command line parameter") Fixes: e1e232ca6b8f ("tracing: Add trace_clock=<clock> kernel parameter") Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/histogram: Fix sorting on old "cpu" valueSteven Rostedt (Google)2022-03-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1d1898f65616c4601208963c3376c1d828cbf2c7 upstream. When trying to add a histogram against an event with the "cpu" field, it was impossible due to "cpu" being a keyword to key off of the running CPU. So to fix this, it was changed to "common_cpu" to match the other generic fields (like "common_pid"). But since some scripts used "cpu" for keying off of the CPU (for events that did not have "cpu" as a field, which is most of them), a backward compatibility trick was added such that if "cpu" was used as a key, and the event did not have "cpu" as a field name, then it would fallback and switch over to "common_cpu". This fix has a couple of subtle bugs. One was that when switching over to "common_cpu", it did not change the field name, it just set a flag. But the code still found a "cpu" field. The "cpu" field is used for filtering and is returned when the event does not have a "cpu" field. This was found by: # cd /sys/kernel/tracing # echo hist:key=cpu,pid:sort=cpu > events/sched/sched_wakeup/trigger # cat events/sched/sched_wakeup/hist Which showed the histogram unsorted: { cpu: 19, pid: 1175 } hitcount: 1 { cpu: 6, pid: 239 } hitcount: 2 { cpu: 23, pid: 1186 } hitcount: 14 { cpu: 12, pid: 249 } hitcount: 2 { cpu: 3, pid: 994 } hitcount: 5 Instead of hard coding the "cpu" checks, take advantage of the fact that trace_event_field_field() returns a special field for "cpu" and "CPU" if the event does not have "cpu" as a field. This special field has the "filter_type" of "FILTER_CPU". Check that to test if the returned field is of the CPU type instead of doing the string compare. Also, fix the sorting bug by testing for the hist_field flag of HIST_FIELD_FL_CPU when setting up the sort routine. Otherwise it will use the special CPU field to know what compare routine to use, and since that special field does not have a size, it returns tracing_map_cmp_none. Cc: stable@vger.kernel.org Fixes: 1e3bac71c505 ("tracing/histogram: Rename "cpu" to "common_cpu"") Reported-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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