linux/kernel/trace/Kconfig, branch v6.14

fprobe: Rewrite fprobe on function-graph tracer

2024-12-26T15:50:05Z

Rewrite fprobe implementation on function-graph tracer. Major API changes are: - 'nr_maxactive' field is deprecated. - This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So currently works only on x86_64. - Currently the entry size is limited in 15 * sizeof(long). - If there is too many fprobe exit handler set on the same function, it will fail to probe. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Heiko Carstens Cc: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Cc: Andrew Morton Link: https://lore.kernel.org/173519003970.391279.14406792285453830996.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC

2024-12-26T15:50:04Z

Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func macro check. This is for the other feature (e.g. FPROBE) which requires to access ftrace_regs from fgraph_ops::entryfunc() can avoid compiling if the fgraph can not pass the valid ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) Cc: Catalin Marinas Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Link: https://lore.kernel.org/173519001472.391279.1174901685282588467.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

2024-12-26T15:50:04Z

Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_FTRACE_REGS_HAVING_PT_REGS, fprobe events will not be able to be used from perf. Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173518999352.391279.13332699755290175168.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe exit handler

2024-12-26T15:50:03Z

Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which means the ftrace_regs is including the pt_regs so that ftrace_regs can provide pt_regs without memory allocation. Fprobe introduces a new dependency with that. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Cc: Huacai Chen Cc: Alexei Starovoitov Cc: Florent Revest Cc: bpf Cc: Alan Maguire Cc: Heiko Carstens Cc: WANG Xuerui Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Song Liu Cc: Jiri Olsa Cc: KP Singh Cc: Matt Bobrowski Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Eduard Zingerman Cc: Yonghong Song Cc: John Fastabend Cc: Stanislav Fomichev Cc: Hao Luo Cc: Andrew Morton Link: https://lore.kernel.org/173518995092.391279.6765116450352977627.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe entry handler

2024-12-26T15:50:03Z

This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe on arm64. Cc: Alexei Starovoitov Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173518994037.391279.2786805566359674586.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest Signed-off-by: Steven Rostedt (Google)

fgraph: Replace fgraph_ret_regs with ftrace_regs

2024-12-26T15:50:02Z

Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens Acked-by: Will Deacon Cc: Catalin Marinas Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Cc: Huacai Chen Cc: WANG Xuerui Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

function_graph: Support recording and printing the function return address

2024-10-05T14:14:04Z

When using function_graph tracer to analyze the flow of kernel function execution, it is often necessary to quickly locate the exact line of code where the call occurs. While this may be easy at times, it can be more time-consuming when some functions are inlined or the flow is too long. This feature aims to simplify the process by recording the return address of traced funcions and printing it when outputing trace logs. To enhance human readability, the prefix 'ret=' is used for the kernel return value, while '<-' serves as the prefix for the return address in trace logs to make it look more like the function tracer. A new trace option named 'funcgraph-retaddr' has been introduced, and the existing option 'sym-addr' can be used to control the format of the return address. See below logs with both funcgraph-retval and funcgraph-retaddr enabled. 0) | load_elf_binary() { /* <-bprm_execve+0x249/0x600 */ 0) | load_elf_phdrs() { /* <-load_elf_binary+0x84/0x1730 */ 0) | __kmalloc_noprof() { /* <-load_elf_phdrs+0x4a/0xb0 */ 0) 3.657 us | __cond_resched(); /* <-__kmalloc_noprof+0x28c/0x390 ret=0x0 */ 0) + 24.335 us | } /* __kmalloc_noprof ret=0xffff8882007f3000 */ 0) | kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */ 0) | rw_verify_area() { /* <-kernel_read+0x2b/0x50 */ 0) | security_file_permission() { /* <-kernel_read+0x2b/0x50 */ 0) | selinux_file_permission() { /* <-security_file_permission+0x26/0x40 */ 0) | __inode_security_revalidate() { /* <-selinux_file_permission+0x6d/0x140 */ 0) 2.034 us | __cond_resched(); /* <-__inode_security_revalidate+0x5f/0x80 ret=0x0 */ 0) 6.602 us | } /* __inode_security_revalidate ret=0x0 */ 0) 2.214 us | avc_policy_seqno(); /* <-selinux_file_permission+0x107/0x140 ret=0x0 */ 0) + 16.670 us | } /* selinux_file_permission ret=0x0 */ 0) + 20.809 us | } /* security_file_permission ret=0x0 */ 0) + 25.217 us | } /* rw_verify_area ret=0x0 */ 0) | __kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */ 0) | ext4_file_read_iter() { /* <-__kernel_read+0x160/0x2e0 */ Then, we can use the faddr2line to locate the source code, for example: $ ./scripts/faddr2line ./vmlinux load_elf_phdrs+0x6c/0xb0 load_elf_phdrs+0x6c/0xb0: elf_read at fs/binfmt_elf.c:471 (inlined by) load_elf_phdrs at fs/binfmt_elf.c:531 Link: https://lore.kernel.org/20240915032912.1118397-1-dolinux.peng@gmail.com Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202409150605.HgUmU8ea-lkp@intel.com/ Signed-off-by: Donglin Peng [ Rebased to handle text_delta offsets ] Signed-off-by: Steven Rostedt (Google)

tracing: Build event generation tests only as modules

2024-06-11T23:43:12Z

The kprobes and synth event generation test modules add events and lock (get a reference) those event file reference in module init function, and unlock and delete it in module exit function. This is because those are designed for playing as modules. If we make those modules as built-in, those events are left locked in the kernel, and never be removed. This causes kprobe event self-test failure as below. [ 97.349708] ------------[ cut here ]------------ [ 97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.357106] Modules linked in: [ 97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14 [ 97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90 [ 97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286 [ 97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000 [ 97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68 [ 97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000 [ 97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000 [ 97.381536] FS: 0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000 [ 97.383813] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0 [ 97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 97.391196] Call Trace: [ 97.391967] [ 97.392647] ? __warn+0xcc/0x180 [ 97.393640] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.395181] ? report_bug+0xbd/0x150 [ 97.396234] ? handle_bug+0x3e/0x60 [ 97.397311] ? exc_invalid_op+0x1a/0x50 [ 97.398434] ? asm_exc_invalid_op+0x1a/0x20 [ 97.399652] ? trace_kprobe_is_busy+0x20/0x20 [ 97.400904] ? tracing_reset_all_online_cpus+0x15/0x90 [ 97.402304] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.403773] ? init_kprobe_trace+0x50/0x50 [ 97.404972] do_one_initcall+0x112/0x240 [ 97.406113] do_initcall_level+0x95/0xb0 [ 97.407286] ? kernel_init+0x1a/0x1a0 [ 97.408401] do_initcalls+0x3f/0x70 [ 97.409452] kernel_init_freeable+0x16f/0x1e0 [ 97.410662] ? rest_init+0x1f0/0x1f0 [ 97.411738] kernel_init+0x1a/0x1a0 [ 97.412788] ret_from_fork+0x39/0x50 [ 97.413817] ? rest_init+0x1f0/0x1f0 [ 97.414844] ret_from_fork_asm+0x11/0x20 [ 97.416285] [ 97.417134] irq event stamp: 13437323 [ 97.418376] hardirqs last enabled at (13437337): [] console_unlock+0x11c/0x150 [ 97.421285] hardirqs last disabled at (13437370): [] console_unlock+0x101/0x150 [ 97.423838] softirqs last enabled at (13437366): [] handle_softirqs+0x23f/0x2a0 [ 97.426450] softirqs last disabled at (13437393): [] __irq_exit_rcu+0x66/0xd0 [ 97.428850] ---[ end trace 0000000000000000 ]--- And also, since we can not cleanup dynamic_event file, ftracetest are failed too. To avoid these issues, build these tests only as modules. Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/ Fixes: 9fe41efaca08 ("tracing: Add synth event generation test module") Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google)

Merge tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-05-18T01:29:30Z

Pull probes updates from Masami Hiramatsu: - tracing/probes: Add new pseudo-types %pd and %pD support for dumping dentry name from 'struct dentry *' and file name from 'struct file *' - uprobes performance optimizations: - Speed up the BPF uprobe event by delaying the fetching of the uprobe event arguments that are not used in BPF - Avoid locking by speculatively checking whether uprobe event is valid - Reduce lock contention by using read/write_lock instead of spinlock for uprobe list operation. This improved BPF uprobe benchmark result 43% on average - rethook: Remove non-fatal warning messages when tracing stack from BPF and skip rcu_is_watching() validation in rethook if possible - objpool: Optimize objpool (which is used by kretprobes and fprobe as rethook backend storage) by inlining functions and avoid caching nr_cpu_ids because it is a const value - fprobe: Add entry/exit callbacks types (code cleanup) - kprobes: Check ftrace was killed in kprobes if it uses ftrace * tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: kprobe/ftrace: bail out if ftrace was killed selftests/ftrace: Fix required features for VFS type test case objpool: cache nr_possible_cpus() and avoid caching nr_cpu_ids objpool: enable inlining objpool_push() and objpool_pop() operations rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get() ftrace: make extra rcu_is_watching() validation check optional uprobes: reduce contention on uprobes_tree access rethook: Remove warning messages printed for finding return address of a frame. fprobe: Add entry/exit callbacks types selftests/ftrace: add fprobe test cases for VFS type "%pd" and "%pD" selftests/ftrace: add kprobe test cases for VFS type "%pd" and "%pD" Documentation: tracing: add new type '%pd' and '%pD' for kprobe tracing/probes: support '%pD' type for print struct file's name tracing/probes: support '%pd' type for print struct dentry's name uprobes: add speculative lockless system-wide uprobe filter check uprobes: prepare uprobe args buffer lazily uprobes: encapsulate preparation of uprobe args buffer

Merge tag 'rcu.next.v6.10' of https://github.com/urezki/linux

2024-05-13T16:49:06Z

Pull RCU updates from Uladzislau Rezki: - Fix a lockdep complain for lazy-preemptible kernel, remove redundant BH disable for TINY_RCU, remove redundant READ_ONCE() in tree.c, fix false positives KCSAN splat and fix buffer overflow in the print_cpu_stall_info(). - Misc updates related to bpf, tracing and update the MAINTAINERS file. - An improvement of a normal synchronize_rcu() call in terms of latency. It maintains a separate track for sync. users only. This approach bypasses per-cpu nocb-lists thus sync-users do not depend on nocb-list length and how fast regular callbacks are processed. - RCU tasks: switch tasks RCU grace periods to sleep at TASK_IDLE priority, fix some comments, add some diagnostic warning to the exit_tasks_rcu_start() and fix a buffer overflow in the show_rcu_tasks_trace_gp_kthread(). - RCU torture: Increase memory to guest OS, fix a Tasks Rude RCU testing, some updates for TREE09, dump mode information to debug GP kthread state, remove redundant READ_ONCE(), fix some comments about RCU_TORTURE_PIPE_LEN and pipe_count, remove some redundant pointer initialization, fix a hung splat task by when the rcutorture tests start to exit, fix invalid context warning, add '--do-kvfree' parameter to torture test and use slow register unregister callbacks only for rcutype test. * tag 'rcu.next.v6.10' of https://github.com/urezki/linux: (48 commits) rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test torture: Scale --do-kvfree test time rcutorture: Fix invalid context warning when enable srcu barrier testing rcutorture: Make stall-tasks directly exit when rcutorture tests end rcutorture: Removing redundant function pointer initialization rcutorture: Make rcutorture support print rcu-tasks gp state rcutorture: Use the gp_kthread_dbg operation specified by cur_ops rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment rcutorture: Remove extraneous rcu_torture_pipe_update_one() READ_ONCE() rcu: Allocate WQ with WQ_MEM_RECLAIM bit set rcu: Support direct wake-up of synchronize_rcu() users rcu: Add a trace event for synchronize_rcu_normal() rcu: Reduce synchronize_rcu() latency rcu: Fix buffer overflow in print_cpu_stall_info() rcu: Mollify sparse with RCU guard rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE() rcu: Remove redundant CONFIG_PROVE_RCU #if condition ...