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2022-11-04tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd()Shang XiaoJing
test_gen_kprobe_cmd() only free buf in fail path, hence buf will leak when there is no failure. Move kfree(buf) from fail path to common path to prevent the memleak. The same reason and solution in test_gen_kretprobe_cmd(). unreferenced object 0xffff888143b14000 (size 2048): comm "insmod", pid 52490, jiffies 4301890980 (age 40.553s) hex dump (first 32 bytes): 70 3a 6b 70 72 6f 62 65 73 2f 67 65 6e 5f 6b 70 p:kprobes/gen_kp 72 6f 62 65 5f 74 65 73 74 20 64 6f 5f 73 79 73 robe_test do_sys backtrace: [<000000006d7b836b>] kmalloc_trace+0x27/0xa0 [<0000000009528b5b>] 0xffffffffa059006f [<000000008408b580>] do_one_initcall+0x87/0x2a0 [<00000000c4980a7e>] do_init_module+0xdf/0x320 [<00000000d775aad0>] load_module+0x3006/0x3390 [<00000000e9a74b80>] __do_sys_finit_module+0x113/0x1b0 [<000000003726480d>] do_syscall_64+0x35/0x80 [<000000003441e93b>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 Link: https://lore.kernel.org/all/20221102072954.26555-1-shangxiaojing@huawei.com/ Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Cc: stable@vger.kernel.org Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-04tracing/fprobe: Fix to check whether fprobe is registered correctlyMasami Hiramatsu (Google)
Since commit ab51e15d535e ("fprobe: Introduce FPROBE_FL_KPROBE_SHARED flag for fprobe") introduced fprobe_kprobe_handler() for fprobe::ops::func, unregister_fprobe() fails to unregister the registered if user specifies FPROBE_FL_KPROBE_SHARED flag. Moreover, __register_ftrace_function() is possible to change the ftrace_ops::func, thus we have to check fprobe::ops::saved_func instead. To check it correctly, it should confirm the fprobe::ops::saved_func is either fprobe_handler() or fprobe_kprobe_handler(). Link: https://lore.kernel.org/all/166677683946.1459107.15997653945538644683.stgit@devnote3/ Fixes: cad9931f64dc ("fprobe: Add ftrace based probe APIs") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-04fprobe: Check rethook_alloc() return in rethook initializationRafael Mendonca
Check if fp->rethook succeeded to be allocated. Otherwise, if rethook_alloc() fails, then we end up dereferencing a NULL pointer in rethook_add_node(). Link: https://lore.kernel.org/all/20221025031209.954836-1-rafaelmendsr@gmail.com/ Fixes: 5b0ab78998e3 ("fprobe: Add exit_handler support") Cc: stable@vger.kernel.org Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-02ftrace: Fix use-after-free for dynamic ftrace_opsLi Huafei
KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization. However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem. [1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468 CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...] Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...] Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...] Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei1@huawei.com Fixes: edb096e00724f ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled") Cc: stable@vger.kernel.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-02ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()Steven Rostedt (Google)
On some machines the number of listed CPUs may be bigger than the actual CPUs that exist. The tracing subsystem allocates a per_cpu directory with access to the per CPU ring buffer via a cpuX file. But to save space, the ring buffer will only allocate buffers for online CPUs, even though the CPU array will be as big as the nr_cpu_ids. With the addition of waking waiters on the ring buffer when closing the file, the ring_buffer_wake_waiters() now needs to make sure that the buffer is allocated (with the irq_work allocated with it) before trying to wake waiters, as it will cause a NULL pointer dereference. While debugging this, I added a NULL check for the buffer itself (which is OK to do), and also NULL pointer checks against buffer->buffers (which is not fine, and will WARN) as well as making sure the CPU number passed in is within the nr_cpu_ids (which is also not fine if it isn't). Link: https://lore.kernel.org/all/87h6zklb6n.wl-tiwai@suse.de/ Link: https://lore.kernel.org/all/CAM6Wdxc0KRJMXVAA0Y=u6Jh2V=uWB-_Fn6M4xRuNppfXzL1mUg@mail.gmail.com/ Link: https://lkml.kernel.org/linux-trace-kernel/20221101191009.1e7378c8@rorschach.local.home Cc: stable@vger.kernel.org Cc: Steven Noonan <steven.noonan@gmail.com> Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1204705 Reported-by: Takashi Iwai <tiwai@suse.de> Reported-by: Roland Ruckerbauer <roland.rucky@gmail.com> Fixes: f3ddb74ad079 ("tracing: Wake up ring buffer waiters on closing of the file") Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-23Merge tag 'perf_urgent_for_v6.1_rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Fix raw data handling when perf events are used in bpf - Rework how SIGTRAPs get delivered to events to address a bunch of problems with it. Add a selftest for that too * tag 'perf_urgent_for_v6.1_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: bpf: Fix sample_flags for bpf_perf_event_output selftests/perf_events: Add a SIGTRAP stress test with disables perf: Fix missing SIGTRAPs
2022-10-21Merge tag 'block-6.1-2022-10-20' of git://git.kernel.dk/linuxLinus Torvalds
Pull block fixes from Jens Axboe: - NVMe pull request via Christoph: - fix nvme-hwmon for DMA non-cohehrent architectures (Serge Semin) - add a nvme-hwmong maintainer (Christoph Hellwig) - fix error pointer dereference in error handling (Dan Carpenter) - fix invalid memory reference in nvmet_subsys_attr_qid_max_show (Daniel Wagner) - don't limit the DMA segment size in nvme-apple (Russell King) - fix workqueue MEM_RECLAIM flushing dependency (Sagi Grimberg) - disable write zeroes on various Kingston SSDs (Xander Li) - fix a memory leak with block device tracing (Ye) - flexible-array fix for ublk (Yushan) - document the ublk recovery feature from this merge window (ZiyangZhang) - remove dead bfq variable in struct (Yuwei) - error handling rq clearing fix (Yu) - add an IRQ safety check for the cached bio freeing (Pavel) - drbd bio cloning fix (Christoph) * tag 'block-6.1-2022-10-20' of git://git.kernel.dk/linux: blktrace: remove unnessary stop block trace in 'blk_trace_shutdown' blktrace: fix possible memleak in '__blk_trace_remove' blktrace: introduce 'blk_trace_{start,stop}' helper bio: safeguard REQ_ALLOC_CACHE bio put block, bfq: remove unused variable for bfq_queue drbd: only clone bio if we have a backing device ublk_drv: use flexible-array member instead of zero-length array nvmet: fix invalid memory reference in nvmet_subsys_attr_qid_max_show nvmet: fix workqueue MEM_RECLAIM flushing dependency nvme-hwmon: kmalloc the NVME SMART log buffer nvme-hwmon: consistently ignore errors from nvme_hwmon_init nvme: add Guenther as nvme-hwmon maintainer nvme-apple: don't limit DMA segement size nvme-pci: disable write zeroes on various Kingston SSD nvme: fix error pointer dereference in error handling Documentation: document ublk user recovery feature blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()
2022-10-20blktrace: remove unnessary stop block trace in 'blk_trace_shutdown'Ye Bin
As previous commit, 'blk_trace_cleanup' will stop block trace if block trace's state is 'Blktrace_running'. So remove unnessary stop block trace in 'blk_trace_shutdown'. Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221019033602.752383-4-yebin@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-20blktrace: fix possible memleak in '__blk_trace_remove'Ye Bin
When test as follows: step1: ioctl(sda, BLKTRACESETUP, &arg) step2: ioctl(sda, BLKTRACESTART, NULL) step3: ioctl(sda, BLKTRACETEARDOWN, NULL) step4: ioctl(sda, BLKTRACESETUP, &arg) Got issue as follows: debugfs: File 'dropped' in directory 'sda' already present! debugfs: File 'msg' in directory 'sda' already present! debugfs: File 'trace0' in directory 'sda' already present! And also find syzkaller report issue like "KASAN: use-after-free Read in relay_switch_subbuf" "https://syzkaller.appspot.com/bug?id=13849f0d9b1b818b087341691be6cc3ac6a6bfb7" If remove block trace without stop(BLKTRACESTOP) block trace, '__blk_trace_remove' will just set 'q->blk_trace' with NULL. However, debugfs file isn't removed, so will report file already present when call BLKTRACESETUP. static int __blk_trace_remove(struct request_queue *q) { struct blk_trace *bt; bt = rcu_replace_pointer(q->blk_trace, NULL, lockdep_is_held(&q->debugfs_mutex)); if (!bt) return -EINVAL; if (bt->trace_state != Blktrace_running) blk_trace_cleanup(q, bt); return 0; } If do test as follows: step1: ioctl(sda, BLKTRACESETUP, &arg) step2: ioctl(sda, BLKTRACESTART, NULL) step3: ioctl(sda, BLKTRACETEARDOWN, NULL) step4: remove sda There will remove debugfs directory which will remove recursively all file under directory. >> blk_release_queue >> debugfs_remove_recursive(q->debugfs_dir) So all files which created in 'do_blk_trace_setup' are removed, and 'dentry->d_inode' is NULL. But 'q->blk_trace' is still in 'running_trace_lock', 'trace_note_tsk' will traverse 'running_trace_lock' all nodes. >>trace_note_tsk >> trace_note >> relay_reserve >> relay_switch_subbuf >> d_inode(buf->dentry)->i_size To solve above issues, reference commit '5afedf670caf', call 'blk_trace_cleanup' unconditionally in '__blk_trace_remove' and first stop block trace in 'blk_trace_cleanup'. Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221019033602.752383-3-yebin@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-20blktrace: introduce 'blk_trace_{start,stop}' helperYe Bin
Introduce 'blk_trace_{start,stop}' helper. No functional changed. Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221019033602.752383-2-yebin@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-17bpf: Fix sample_flags for bpf_perf_event_outputSumanth Korikkar
* Raw data is also filled by bpf_perf_event_output. * Add sample_flags to indicate raw data. * This eliminates the segfaults as shown below: Run ./samples/bpf/trace_output BUG pid 9 cookie 1001000000004 sized 4 BUG pid 9 cookie 1001000000004 sized 4 BUG pid 9 cookie 1001000000004 sized 4 Segmentation fault (core dumped) Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data") Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/r/20221007081327.1047552-1-sumanthk@linux.ibm.com
2022-10-13Merge tag 'trace-v6.1-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Found that the synthetic events were using strlen/strscpy() on values that could have come from userspace, and that is bad. Consolidate the string logic of kprobe and eprobe and extend it to the synthetic events to safely process string addresses. - Clean up content of text dump in ftrace_bug() where the output does not make char reads into signed and sign extending the byte output. - Fix some kernel docs in the ring buffer code. * tag 'trace-v6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Fix reading strings from synthetic events tracing: Add "(fault)" name injection to kernel probes tracing: Move duplicate code of trace_kprobe/eprobe.c into header ring-buffer: Fix kernel-doc ftrace: Fix char print issue in print_ip_ins()
2022-10-12tracing: Fix reading strings from synthetic eventsSteven Rostedt (Google)
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>
2022-10-12tracing: Add "(fault)" name injection to kernel probesSteven Rostedt (Google)
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>
2022-10-12tracing: Move duplicate code of trace_kprobe/eprobe.c into headerSteven Rostedt (Google)
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>
2022-10-12ring-buffer: Fix kernel-docJiapeng Chong
kernel/trace/ring_buffer.c:895: warning: expecting prototype for ring_buffer_nr_pages_dirty(). Prototype was for ring_buffer_nr_dirty_pages() instead. kernel/trace/ring_buffer.c:5313: warning: expecting prototype for ring_buffer_reset_cpu(). Prototype was for ring_buffer_reset_online_cpus() instead. kernel/trace/ring_buffer.c:5382: warning: expecting prototype for rind_buffer_empty(). Prototype was for ring_buffer_empty() instead. Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2340 Link: https://lkml.kernel.org/r/20221009020642.12506-1-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-12ftrace: Fix char print issue in print_ip_ins()Zheng Yejian
When ftrace bug happened, following log shows every hex data in problematic ip address: actual: ffffffe8:6b:ffffffd9:01:21 But so many 'f's seem a little confusing, and that is because format '%x' being used to print signed chars in array 'ins'. As suggested by Joe, change to use format "%*phC" to print array 'ins'. After this patch, the log is like: actual: e8:6b:d9:01:21 Link: https://lkml.kernel.org/r/20221011120352.1878494-1-zhengyejian1@huawei.com Fixes: 6c14133d2d3f ("ftrace: Do not blindly read the ip address in ftrace_bug()") Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-10Merge tag 'trace-v6.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: "Major changes: - Changed location of tracing repo from personal git repo to: git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git - Added Masami Hiramatsu as co-maintainer - Updated MAINTAINERS file to separate out FTRACE as it is more than just TRACING. Minor changes: - Added Mark Rutland as FTRACE reviewer - Updated user_events to make it on its way to remove the BROKEN tag. The changes should now be acceptable but will run it through a cycle and hopefully we can remove the BROKEN tag next release. - Added filtering to eprobes - Added a delta time to the benchmark trace event - Have the histogram and filter callbacks called via a switch statement instead of indirect functions. This speeds it up to avoid retpolines. - Add a way to wake up ring buffer waiters waiting for the ring buffer to fill up to its watermark. - New ioctl() on the trace_pipe_raw file to wake up ring buffer waiters. - Wake up waiters when the ring buffer is disabled. A reader may block when the ring buffer is disabled, but if it was blocked when the ring buffer is disabled it should then wake up. Fixes: - Allow splice to read partially read ring buffer pages. This fixes splice never moving forward. - Fix inverted compare that made the "shortest" ring buffer wait queue actually the longest. - Fix a race in the ring buffer between resetting a page when a writer goes to another page, and the reader. - Fix ftrace accounting bug when function hooks are added at boot up before the weak functions are set to "disabled". - Fix bug that freed a user allocated snapshot buffer when enabling a tracer. - Fix possible recursive locks in osnoise tracer - Fix recursive locking direct functions - Other minor clean ups and fixes" * tag 'trace-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (44 commits) ftrace: Create separate entry in MAINTAINERS for function hooks tracing: Update MAINTAINERS to reflect new tracing git repo tracing: Do not free snapshot if tracer is on cmdline ftrace: Still disable enabled records marked as disabled tracing/user_events: Move pages/locks into groups to prepare for namespaces tracing: Add Masami Hiramatsu as co-maintainer tracing: Remove unused variable 'dups' MAINTAINERS: add myself as a tracing reviewer ring-buffer: Fix race between reset page and reading page tracing/user_events: Update ABI documentation to align to bits vs bytes tracing/user_events: Use bits vs bytes for enabled status page data tracing/user_events: Use refcount instead of atomic for ref tracking tracing/user_events: Ensure user provided strings are safely formatted tracing/user_events: Use WRITE instead of READ for io vector import tracing/user_events: Use NULL for strstr checks tracing: Fix spelling mistake "preapre" -> "prepare" tracing: Wake up waiters when tracing is disabled tracing: Add ioctl() to force ring buffer waiters to wake up tracing: Wake up ring buffer waiters on closing of the file ring-buffer: Add ring_buffer_wake_waiters() ...
2022-10-10Merge tag 'perf-core-2022-10-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events updates from Ingo Molnar: "PMU driver updates: - Add AMD Last Branch Record Extension Version 2 (LbrExtV2) feature support for Zen 4 processors. - Extend the perf ABI to provide branch speculation information, if available, and use this on CPUs that have it (eg. LbrExtV2). - Improve Intel PEBS TSC timestamp handling & integration. - Add Intel Raptor Lake S CPU support. - Add 'perf mem' and 'perf c2c' memory profiling support on AMD CPUs by utilizing IBS tagged load/store samples. - Clean up & optimize various x86 PMU details. HW breakpoints: - Big rework to optimize the code for systems with hundreds of CPUs and thousands of breakpoints: - Replace the nr_bp_mutex global mutex with the bp_cpuinfo_sem per-CPU rwsem that is read-locked during most of the key operations. - Improve the O(#cpus * #tasks) logic in toggle_bp_slot() and fetch_bp_busy_slots(). - Apply micro-optimizations & cleanups. - Misc cleanups & enhancements" * tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) perf/hw_breakpoint: Annotate tsk->perf_event_mutex vs ctx->mutex perf: Fix pmu_filter_match() perf: Fix lockdep_assert_event_ctx() perf/x86/amd/lbr: Adjust LBR regardless of filtering perf/x86/utils: Fix uninitialized var in get_branch_type() perf/uapi: Define PERF_MEM_SNOOPX_PEER in kernel header file perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR perf/x86/amd: Support PERF_SAMPLE_ADDR perf/x86/amd: Support PERF_SAMPLE_{WEIGHT|WEIGHT_STRUCT} perf/x86/amd: Support PERF_SAMPLE_DATA_SRC perf/x86/amd: Add IBS OP_DATA2 DataSrc bit definitions perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO} perf/x86/uncore: Add new Raptor Lake S support perf/x86/cstate: Add new Raptor Lake S support perf/x86/msr: Add new Raptor Lake S support perf/x86: Add new Raptor Lake S support bpf: Check flags for branch stack in bpf_read_branch_records helper perf, hw_breakpoint: Fix use-after-free if perf_event_open() fails perf: Use sample_flags for raw_data perf: Use sample_flags for addr ...
2022-10-05tracing: Do not free snapshot if tracer is on cmdlineSteven Rostedt (Google)
The ftrace_boot_snapshot and alloc_snapshot cmdline options allocate the snapshot buffer at boot up for use later. The ftrace_boot_snapshot in particular requires the snapshot to be allocated because it will take a snapshot at the end of boot up allowing to see the traces that happened during boot so that it's not lost when user space takes over. When a tracer is registered (started) there's a path that checks if it requires the snapshot buffer or not, and if it does not and it was allocated it will do a synchronization and free the snapshot buffer. This is only required if the previous tracer was using it for "max latency" snapshots, as it needs to make sure all max snapshots are complete before freeing. But this is only needed if the previous tracer was using the snapshot buffer for latency (like irqoff tracer and friends). But it does not make sense to free it, if the previous tracer was not using it, and the snapshot was allocated by the cmdline parameters. This basically takes away the point of allocating it in the first place! Note, the allocated snapshot worked fine for just trace events, but fails when a tracer is enabled on the cmdline. Further investigation, this goes back even further and it does not require a tracer on the cmdline to fail. Simply enable snapshots and then enable a tracer, and it will remove the snapshot. Link: https://lkml.kernel.org/r/20221005113757.041df7fe@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: 45ad21ca5530 ("tracing: Have trace_array keep track if snapshot buffer is allocated") Reported-by: Ross Zwisler <zwisler@kernel.org> Tested-by: Ross Zwisler <zwisler@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-05ftrace: Still disable enabled records marked as disabledSteven Rostedt (Google)
Weak functions started causing havoc as they showed up in the "available_filter_functions" and this confused people as to why some functions marked as "notrace" were listed, but when enabled they did nothing. This was because weak functions can still have fentry calls, and these addresses get added to the "available_filter_functions" file. kallsyms is what converts those addresses to names, and since the weak functions are not listed in kallsyms, it would just pick the function before that. To solve this, there was a trick to detect weak functions listed, and these records would be marked as DISABLED so that they do not get enabled and are mostly ignored. As the processing of the list of all functions to figure out what is weak or not can take a long time, this process is put off into a kernel thread and run in parallel with the rest of start up. Now the issue happens whet function tracing is enabled via the kernel command line. As it starts very early in boot up, it can be enabled before the records that are weak are marked to be disabled. This causes an issue in the accounting, as the weak records are enabled by the command line function tracing, but after boot up, they are not disabled. The ftrace records have several accounting flags and a ref count. The DISABLED flag is just one. If the record is enabled before it is marked DISABLED it will get an ENABLED flag and also have its ref counter incremented. After it is marked for DISABLED, neither the ENABLED flag nor the ref counter is cleared. There's sanity checks on the records that are performed after an ftrace function is registered or unregistered, and this detected that there were records marked as ENABLED with ref counter that should not have been. Note, the module loading code uses the DISABLED flag as well to keep its functions from being modified while its being loaded and some of these flags may get set in this process. So changing the verification code to ignore DISABLED records is a no go, as it still needs to verify that the module records are working too. Also, the weak functions still are calling a trampoline. Even though they should never be called, it is dangerous to leave these weak functions calling a trampoline that is freed, so they should still be set back to nops. There's two places that need to not skip records that have the ENABLED and the DISABLED flags set. That is where the ftrace_ops is processed and sets the records ref counts, and then later when the function itself is to be updated, and the ENABLED flag gets removed. Add a helper function "skip_record()" that returns true if the record has the DISABLED flag set but not the ENABLED flag. Link: https://lkml.kernel.org/r/20221005003809.27d2b97b@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid adding weak function") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-03Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-10-03 We've added 143 non-merge commits during the last 27 day(s) which contain a total of 151 files changed, 8321 insertions(+), 1402 deletions(-). The main changes are: 1) Add kfuncs for PKCS#7 signature verification from BPF programs, from Roberto Sassu. 2) Add support for struct-based arguments for trampoline based BPF programs, from Yonghong Song. 3) Fix entry IP for kprobe-multi and trampoline probes under IBT enabled, from Jiri Olsa. 4) Batch of improvements to veristat selftest tool in particular to add CSV output, a comparison mode for CSV outputs and filtering, from Andrii Nakryiko. 5) Add preparatory changes needed for the BPF core for upcoming BPF HID support, from Benjamin Tissoires. 6) Support for direct writes to nf_conn's mark field from tc and XDP BPF program types, from Daniel Xu. 7) Initial batch of documentation improvements for BPF insn set spec, from Dave Thaler. 8) Add a new BPF_MAP_TYPE_USER_RINGBUF map which provides single-user-space-producer / single-kernel-consumer semantics for BPF ring buffer, from David Vernet. 9) Follow-up fixes to BPF allocator under RT to always use raw spinlock for the BPF hashtab's bucket lock, from Hou Tao. 10) Allow creating an iterator that loops through only the resources of one task/thread instead of all, from Kui-Feng Lee. 11) Add support for kptrs in the per-CPU arraymap, from Kumar Kartikeya Dwivedi. 12) Add a new kfunc helper for nf to set src/dst NAT IP/port in a newly allocated CT entry which is not yet inserted, from Lorenzo Bianconi. 13) Remove invalid recursion check for struct_ops for TCP congestion control BPF programs, from Martin KaFai Lau. 14) Fix W^X issue with BPF trampoline and BPF dispatcher, from Song Liu. 15) Fix percpu_counter leakage in BPF hashtab allocation error path, from Tetsuo Handa. 16) Various cleanups in BPF selftests to use preferred ASSERT_* macros, from Wang Yufen. 17) Add invocation for cgroup/connect{4,6} BPF programs for ICMP pings, from YiFei Zhu. 18) Lift blinding decision under bpf_jit_harden = 1 to bpf_capable(), from Yauheni Kaliuta. 19) Various libbpf fixes and cleanups including a libbpf NULL pointer deref, from Xin Liu. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (143 commits) net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.c Documentation: bpf: Add implementation notes documentations to table of contents bpf, docs: Delete misformatted table. selftests/xsk: Fix double free bpftool: Fix error message of strerror libbpf: Fix overrun in netlink attribute iteration selftests/bpf: Fix spelling mistake "unpriviledged" -> "unprivileged" samples/bpf: Fix typo in xdp_router_ipv4 sample bpftool: Remove unused struct event_ring_info bpftool: Remove unused struct btf_attach_point bpf, docs: Add TOC and fix formatting. bpf, docs: Add Clang note about BPF_ALU bpf, docs: Move Clang notes to a separate file bpf, docs: Linux byteswap note bpf, docs: Move legacy packet instructions to a separate file selftests/bpf: Check -EBUSY for the recurred bpf_setsockopt(TCP_CONGESTION) bpf: tcp: Stop bpf_setsockopt(TCP_CONGESTION) in init ops to recur itself bpf: Refactor bpf_setsockopt(TCP_CONGESTION) handling into another function bpf: Move the "cdg" tcp-cc check to the common sol_tcp_sockopt() bpf: Add __bpf_prog_{enter,exit}_struct_ops for struct_ops trampoline ... ==================== Link: https://lore.kernel.org/r/20221003194915.11847-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-03tracing/user_events: Move pages/locks into groups to prepare for namespacesBeau Belgrave
In order to enable namespaces or any sort of isolation within user_events the register lock and pages need to be broken up into groups. Each event and file now has a group pointer which stores the actual pages to map, lookup data and synchronization objects. This only enables a single group that maps to init_user_ns, as IMA namespace has done. This enables user_events to start the work of supporting namespaces by walking the namespaces up to the init_user_ns. Future patches will address other user namespaces and will align to the approaches the IMA namespace uses. Link: https://lore.kernel.org/linux-kernel/20220915193221.1728029-15-stefanb@linux.ibm.com/#t Link: https://lkml.kernel.org/r/20221001001016.2832-2-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-03tracing: Remove unused variable 'dups'Chen Zhongjin
Reported by Clang [-Wunused-but-set-variable] 'commit c193707dde77 ("tracing: Remove code which merges duplicates")' This commit removed the code which merges duplicates in detect_dups(), but forgot to delete the variable 'dups' which used to merge duplicates in the loop. Now only 'total_dups' is needed, remove 'dups' for clean code. Link: https://lkml.kernel.org/r/20220930103236.253985-1-chenzhongjin@huawei.com Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29ring-buffer: Fix race between reset page and reading pageSteven Rostedt (Google)
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>
2022-09-29tracing/user_events: Use bits vs bytes for enabled status page dataBeau Belgrave
User processes may require many events and when they do the cache performance of a byte index status check is less ideal than a bit index. The previous event limit per-page was 4096, the new limit is 32,768. This change adds a bitwise index to the user_reg struct. Programs check that the bit at status_bit has a bit set within the status page(s). Link: https://lkml.kernel.org/r/20220728233309.1896-6-beaub@linux.microsoft.com Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/ Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29tracing/user_events: Use refcount instead of atomic for ref trackingBeau Belgrave
User processes could open up enough event references to cause rollovers. These could cause use after free scenarios, which we do not want. Switching to refcount APIs prevent this, but will leak memory once saturated. Once saturated, user processes can still use the events. This prevents a bad user process from stopping existing telemetry from being emitted. Link: https://lkml.kernel.org/r/20220728233309.1896-5-beaub@linux.microsoft.com Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/ Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29tracing/user_events: Ensure user provided strings are safely formattedBeau Belgrave
User processes can provide bad strings that may cause issues or leak kernel details back out. Don't trust the content of these strings when formatting strings for matching. This also moves to a consistent dynamic length string creation model. Link: https://lkml.kernel.org/r/20220728233309.1896-4-beaub@linux.microsoft.com Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/ Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29tracing/user_events: Use WRITE instead of READ for io vector importBeau Belgrave
import_single_range expects the direction/rw to be where it came from, not the protection/limit. Since the import is in a write path use WRITE. Link: https://lkml.kernel.org/r/20220728233309.1896-3-beaub@linux.microsoft.com Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/ Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29tracing/user_events: Use NULL for strstr checksBeau Belgrave
Trivial fix to ensure strstr checks use NULL instead of 0. Link: https://lkml.kernel.org/r/20220728233309.1896-2-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29tracing: Fix spelling mistake "preapre" -> "prepare"Colin Ian King
There is a spelling mistake in the trace text. Fix it. Link: https://lkml.kernel.org/r/20220928215828.66325-1-colin.i.king@gmail.com Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-29tracing: Wake up waiters when tracing is disabledSteven Rostedt (Google)
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>
2022-09-29tracing: Add ioctl() to force ring buffer waiters to wake upSteven Rostedt (Google)
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>
2022-09-29Merge branch 'v6.0-rc7'Peter Zijlstra
Merge upstream to get RAPTORLAKE_S Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-09-28tracing: Wake up ring buffer waiters on closing of the fileSteven Rostedt (Google)
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>
2022-09-28ring-buffer: Add ring_buffer_wake_waiters()Steven Rostedt (Google)
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>
2022-09-27ring-buffer: Check pending waiters when doing wake ups as wellSteven Rostedt (Google)
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>
2022-09-27ring-buffer: Have the shortest_full queue be the shortest not longestSteven Rostedt (Google)
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>
2022-09-27bpf: Check flags for branch stack in bpf_read_branch_records helperJiri Olsa
Recent commit [1] changed branch stack data indication from br_stack pointer to sample_flags in perf_sample_data struct. We need to check sample_flags for PERF_SAMPLE_BRANCH_STACK bit for valid branch stack data. [1] a9a931e26668 ("perf: Use sample_flags for branch stack") Fixes: a9a931e26668 ("perf: Use sample_flags for branch stack") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20220927203259.590950-1-jolsa@kernel.org
2022-09-27ring-buffer: Allow splice to read previous partially read pagesSteven Rostedt (Google)
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>
2022-09-27ftrace: Fix recursive locking direct_mutex in ftrace_modify_direct_callerSong Liu
Naveen reported recursive locking of direct_mutex with sample ftrace-direct-modify.ko: [ 74.762406] WARNING: possible recursive locking detected [ 74.762887] 6.0.0-rc6+ #33 Not tainted [ 74.763216] -------------------------------------------- [ 74.763672] event-sample-fn/1084 is trying to acquire lock: [ 74.764152] ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \ register_ftrace_function+0x1f/0x180 [ 74.764922] [ 74.764922] but task is already holding lock: [ 74.765421] ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \ modify_ftrace_direct+0x34/0x1f0 [ 74.766142] [ 74.766142] other info that might help us debug this: [ 74.766701] Possible unsafe locking scenario: [ 74.766701] [ 74.767216] CPU0 [ 74.767437] ---- [ 74.767656] lock(direct_mutex); [ 74.767952] lock(direct_mutex); [ 74.768245] [ 74.768245] *** DEADLOCK *** [ 74.768245] [ 74.768750] May be due to missing lock nesting notation [ 74.768750] [ 74.769332] 1 lock held by event-sample-fn/1084: [ 74.769731] #0: ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \ modify_ftrace_direct+0x34/0x1f0 [ 74.770496] [ 74.770496] stack backtrace: [ 74.770884] CPU: 4 PID: 1084 Comm: event-sample-fn Not tainted ... [ 74.771498] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... [ 74.772474] Call Trace: [ 74.772696] <TASK> [ 74.772896] dump_stack_lvl+0x44/0x5b [ 74.773223] __lock_acquire.cold.74+0xac/0x2b7 [ 74.773616] lock_acquire+0xd2/0x310 [ 74.773936] ? register_ftrace_function+0x1f/0x180 [ 74.774357] ? lock_is_held_type+0xd8/0x130 [ 74.774744] ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [ 74.775213] __mutex_lock+0x99/0x1010 [ 74.775536] ? register_ftrace_function+0x1f/0x180 [ 74.775954] ? slab_free_freelist_hook.isra.43+0x115/0x160 [ 74.776424] ? ftrace_set_hash+0x195/0x220 [ 74.776779] ? register_ftrace_function+0x1f/0x180 [ 74.777194] ? kfree+0x3e1/0x440 [ 74.777482] ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [ 74.777941] ? __schedule+0xb40/0xb40 [ 74.778258] ? register_ftrace_function+0x1f/0x180 [ 74.778672] ? my_tramp1+0xf/0xf [ftrace_direct_modify] [ 74.779128] register_ftrace_function+0x1f/0x180 [ 74.779527] ? ftrace_set_filter_ip+0x33/0x70 [ 74.779910] ? __schedule+0xb40/0xb40 [ 74.780231] ? my_tramp1+0xf/0xf [ftrace_direct_modify] [ 74.780678] ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [ 74.781147] ftrace_modify_direct_caller+0x5b/0x90 [ 74.781563] ? 0xffffffffa0201000 [ 74.781859] ? my_tramp1+0xf/0xf [ftrace_direct_modify] [ 74.782309] modify_ftrace_direct+0x1b2/0x1f0 [ 74.782690] ? __schedule+0xb40/0xb40 [ 74.783014] ? simple_thread+0x2a/0xb0 [ftrace_direct_modify] [ 74.783508] ? __schedule+0xb40/0xb40 [ 74.783832] ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [ 74.784294] simple_thread+0x76/0xb0 [ftrace_direct_modify] [ 74.784766] kthread+0xf5/0x120 [ 74.785052] ? kthread_complete_and_exit+0x20/0x20 [ 74.785464] ret_from_fork+0x22/0x30 [ 74.785781] </TASK> Fix this by using register_ftrace_function_nolock in ftrace_modify_direct_caller. Link: https://lkml.kernel.org/r/20220927004146.1215303-1-song@kernel.org Fixes: 53cd885bc5c3 ("ftrace: Allow IPMODIFY and DIRECT ops on the same function") Reported-and-tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-27ftrace: Properly unset FTRACE_HASH_FL_MODZheng Yejian
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>
2022-09-27tracing/eprobe: Fix alloc event dir failed when event name no setTao Chen
The event dir will alloc failed when event name no set, using the command: "echo "e:esys/ syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events" It seems that dir name="syscalls/sys_enter_openat" is not allowed in debugfs. So just use the "sys_enter_openat" as the event name. Link: https://lkml.kernel.org/r/1664028814-45923-1-git-send-email-chentao.kernel@linux.alibaba.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Linyu Yuan <quic_linyyuan@quicinc.com> Cc: Tao Chen <chentao.kernel@linux.alibaba.com Cc: stable@vger.kernel.org Fixes: 95c104c378dc ("tracing: Auto generate event name when creating a group of events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Tao Chen <chentao.kernel@linux.alibaba.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-27tracing: Disable interrupt or preemption before acquiring arch_spinlock_tWaiman Long
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>
2022-09-26bpf: Return value in kprobe get_func_ip only for entry addressJiri Olsa
Changing return value of kprobe's version of bpf_get_func_ip to return zero if the attach address is not on the function's entry point. For kprobes attached in the middle of the function we can't easily get to the function address especially now with the CONFIG_X86_KERNEL_IBT support. If user cares about current IP for kprobes attached within the function body, they can get it with PT_REGS_IP(ctx). Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220926153340.1621984-6-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-26bpf: Adjust kprobe_multi entry_ip for CONFIG_X86_KERNEL_IBTJiri Olsa
Martynas reported bpf_get_func_ip returning +4 address when CONFIG_X86_KERNEL_IBT option is enabled. When CONFIG_X86_KERNEL_IBT is enabled we'll have endbr instruction at the function entry, which screws return value of bpf_get_func_ip() helper that should return the function address. There's short term workaround for kprobe_multi bpf program made by Alexei [1], but we need this fixup also for bpf_get_attach_cookie, that returns cookie based on the entry_ip value. Moving the fixup in the fprobe handler, so both bpf_get_func_ip and bpf_get_attach_cookie get expected function address when CONFIG_X86_KERNEL_IBT option is enabled. Also renaming kprobe_multi_link_handler entry_ip argument to fentry_ip so it's clearer this is an ftrace __fentry__ ip. [1] commit 7f0059b58f02 ("selftests/bpf: Fix kprobe_multi test.") Cc: Peter Zijlstra <peterz@infradead.org> Reported-by: Martynas Pumputis <m@lambda.lt> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220926153340.1621984-5-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-26ftrace: Keep the resolved addr in kallsyms_callbackJiri Olsa
Keeping the resolved 'addr' in kallsyms_callback, instead of taking ftrace_location value, because we depend on symbol address in the cookie related code. With CONFIG_X86_KERNEL_IBT option the ftrace_location value differs from symbol address, which screwes the symbol address cookies matching. There are 2 users of this function: - bpf_kprobe_multi_link_attach for which this fix is for - get_ftrace_locations which is used by register_fprobe_syms this function needs to get symbols resolved to addresses, but does not need 'ftrace location addresses' at this point there's another ftrace location translation in the path done by ftrace_set_filter_ips call: register_fprobe_syms addrs = get_ftrace_locations register_fprobe_ips(addrs) ... ftrace_set_filter_ips ... __ftrace_match_addr ip = ftrace_location(ip); ... Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220926153340.1621984-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-26rv/monitor: Add __init/__exit annotations to module init/exit funcsXiu Jianfeng
Add missing __init/__exit annotations to module init/exit funcs. Link: https://lkml.kernel.org/r/20220922103208.162869-1-xiujianfeng@huawei.com Fixes: 24bce201d798 ("tools/rv: Add dot2k") Fixes: 8812d21219b9 ("rv/monitor: Add the wip monitor skeleton created by dot2k") Fixes: ccc319dcb450 ("rv/monitor: Add the wwnr monitor") Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-26tracing/osnoise: Fix possible recursive locking in stop_per_cpu_kthreadsNico Pache
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>
2022-09-26tracing: kprobe: Make gen test module work in arm and riscvYipeng Zou
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>
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