aboutsummaryrefslogtreecommitdiff
path: root/kernel/trace/trace_kprobe.c
AgeCommit message (Collapse)AuthorFilesLines
2025-11-04tracing: Allow tracer to add more than 32 optionsMasami Hiramatsu (Google)1-3/+3
Since enum trace_iterator_flags is 32bit, the max number of the option flags is limited to 32 and it is fully used now. To add a new option, we need to expand it. So replace the TRACE_ITER_##flag with TRACE_ITER(flag) macro which is 64bit bitmask. Link: https://lore.kernel.org/all/176187877103.994619.166076000668757232.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-10-02tracing: Fix race condition in kprobe initialization causing NULL pointer ↵Yuan Chen1-4/+7
dereference There is a critical race condition in kprobe initialization that can lead to NULL pointer dereference and kernel crash. [1135630.084782] Unable to handle kernel paging request at virtual address 0000710a04630000 ... [1135630.260314] pstate: 404003c9 (nZcv DAIF +PAN -UAO) [1135630.269239] pc : kprobe_perf_func+0x30/0x260 [1135630.277643] lr : kprobe_dispatcher+0x44/0x60 [1135630.286041] sp : ffffaeff4977fa40 [1135630.293441] x29: ffffaeff4977fa40 x28: ffffaf015340e400 [1135630.302837] x27: 0000000000000000 x26: 0000000000000000 [1135630.312257] x25: ffffaf029ed108a8 x24: ffffaf015340e528 [1135630.321705] x23: ffffaeff4977fc50 x22: ffffaeff4977fc50 [1135630.331154] x21: 0000000000000000 x20: ffffaeff4977fc50 [1135630.340586] x19: ffffaf015340e400 x18: 0000000000000000 [1135630.349985] x17: 0000000000000000 x16: 0000000000000000 [1135630.359285] x15: 0000000000000000 x14: 0000000000000000 [1135630.368445] x13: 0000000000000000 x12: 0000000000000000 [1135630.377473] x11: 0000000000000000 x10: 0000000000000000 [1135630.386411] x9 : 0000000000000000 x8 : 0000000000000000 [1135630.395252] x7 : 0000000000000000 x6 : 0000000000000000 [1135630.403963] x5 : 0000000000000000 x4 : 0000000000000000 [1135630.412545] x3 : 0000710a04630000 x2 : 0000000000000006 [1135630.421021] x1 : ffffaeff4977fc50 x0 : 0000710a04630000 [1135630.429410] Call trace: [1135630.434828] kprobe_perf_func+0x30/0x260 [1135630.441661] kprobe_dispatcher+0x44/0x60 [1135630.448396] aggr_pre_handler+0x70/0xc8 [1135630.454959] kprobe_breakpoint_handler+0x140/0x1e0 [1135630.462435] brk_handler+0xbc/0xd8 [1135630.468437] do_debug_exception+0x84/0x138 [1135630.475074] el1_dbg+0x18/0x8c [1135630.480582] security_file_permission+0x0/0xd0 [1135630.487426] vfs_write+0x70/0x1c0 [1135630.493059] ksys_write+0x5c/0xc8 [1135630.498638] __arm64_sys_write+0x24/0x30 [1135630.504821] el0_svc_common+0x78/0x130 [1135630.510838] el0_svc_handler+0x38/0x78 [1135630.516834] el0_svc+0x8/0x1b0 kernel/trace/trace_kprobe.c: 1308 0xffff3df8995039ec <kprobe_perf_func+0x2c>: ldr x21, [x24,#120] include/linux/compiler.h: 294 0xffff3df8995039f0 <kprobe_perf_func+0x30>: ldr x1, [x21,x0] kernel/trace/trace_kprobe.c 1308: head = this_cpu_ptr(call->perf_events); 1309: if (hlist_empty(head)) 1310: return 0; crash> struct trace_event_call -o struct trace_event_call { ... [120] struct hlist_head *perf_events; //(call->perf_event) ... } crash> struct trace_event_call ffffaf015340e528 struct trace_event_call { ... perf_events = 0xffff0ad5fa89f088, //this value is correct, but x21 = 0 ... } Race Condition Analysis: The race occurs between kprobe activation and perf_events initialization: CPU0 CPU1 ==== ==== perf_kprobe_init perf_trace_event_init tp_event->perf_events = list;(1) tp_event->class->reg (2)← KPROBE ACTIVE Debug exception triggers ... kprobe_dispatcher kprobe_perf_func (tk->tp.flags & TP_FLAG_PROFILE) head = this_cpu_ptr(call->perf_events)(3) (perf_events is still NULL) Problem: 1. CPU0 executes (1) assigning tp_event->perf_events = list 2. CPU0 executes (2) enabling kprobe functionality via class->reg() 3. CPU1 triggers and reaches kprobe_dispatcher 4. CPU1 checks TP_FLAG_PROFILE - condition passes (step 2 completed) 5. CPU1 calls kprobe_perf_func() and crashes at (3) because call->perf_events is still NULL CPU1 sees that kprobe functionality is enabled but does not see that perf_events has been assigned. Add pairing read and write memory barriers to guarantee that if CPU1 sees that kprobe functionality is enabled, it must also see that perf_events has been assigned. Link: https://lore.kernel.org/all/20251001022025.44626-1-chenyuan_fl@163.com/ Fixes: 50d780560785 ("tracing/kprobes: Add probe handler dispatcher to support perf and ftrace concurrent use") Cc: stable@vger.kernel.org Signed-off-by: Yuan Chen <chenyuan@kylinos.cn> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-09-18tracing: kprobe-event: Fix null-ptr-deref in trace_kprobe_create_internal()Wang Liang1-0/+2
A crash was observed with the following output: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 2899 Comm: syz.2.399 Not tainted 6.17.0-rc5+ #5 PREEMPT(none) RIP: 0010:trace_kprobe_create_internal+0x3fc/0x1440 kernel/trace/trace_kprobe.c:911 Call Trace: <TASK> trace_kprobe_create_cb+0xa2/0xf0 kernel/trace/trace_kprobe.c:1089 trace_probe_create+0xf1/0x110 kernel/trace/trace_probe.c:2246 dyn_event_create+0x45/0x70 kernel/trace/trace_dynevent.c:128 create_or_delete_trace_kprobe+0x5e/0xc0 kernel/trace/trace_kprobe.c:1107 trace_parse_run_command+0x1a5/0x330 kernel/trace/trace.c:10785 vfs_write+0x2b6/0xd00 fs/read_write.c:684 ksys_write+0x129/0x240 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x5d/0x2d0 arch/x86/entry/syscall_64.c:94 </TASK> Function kmemdup() may return NULL in trace_kprobe_create_internal(), add check for it's return value. Link: https://lore.kernel.org/all/20250916075816.3181175-1-wangliang74@huawei.com/ Fixes: 33b4e38baa03 ("tracing: kprobe-event: Allocate string buffers from heap") Signed-off-by: Wang Liang <wangliang74@huawei.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-07-24tracing: kprobe-event: Allocate string buffers from heapMasami Hiramatsu (Google)1-14/+25
Allocate temporary string buffers for parsing kprobe-events from heap instead of stack. Link: https://lore.kernel.org/all/175323427627.57270.5105357260879695051.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24tracing: probe: Allocate traceprobe_parse_context from heapMasami Hiramatsu (Google)1-3/+7
Instead of allocating traceprobe_parse_context on stack, allocate it dynamically from heap (slab). This change is likely intended to prevent potential stack overflow issues, which can be a concern in the kernel environment where stack space is limited. Link: https://lore.kernel.org/all/175323425650.57270.280750740753792504.stgit@devnote2/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202506240416.nZIhDXoO-lkp@intel.com/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24tracing: probes: Sort #include alphabeticallyMasami Hiramatsu (Google)1-4/+4
Sort the #include directives in trace_probe* files alphabetically for easier maintenance and avoid double includes. This also groups headers as linux-generic, asm-generic, and local headers. Link: https://lore.kernel.org/all/175323424678.57270.11975372127870059007.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-05-13tracing: probes: Fix a possible race in trace_probe_log APIsMasami Hiramatsu (Google)1-1/+1
Since the shared trace_probe_log variable can be accessed and modified via probe event create operation of kprobe_events, uprobe_events, and dynamic_events, it should be protected. In the dynamic_events, all operations are serialized by `dyn_event_ops_mutex`. But kprobe_events and uprobe_events interfaces are not serialized. To solve this issue, introduces dyn_event_create(), which runs create() operation under the mutex, for kprobe_events and uprobe_events. This also uses lockdep to check the mutex is held when using trace_probe_log* APIs. Link: https://lore.kernel.org/all/174684868120.551552.3068655787654268804.stgit@devnote2/ Reported-by: Paul Cacheux <paulcacheux@gmail.com> Closes: https://lore.kernel.org/all/20250510074456.805a16872b591e2971a4d221@kernel.org/ Fixes: ab105a4fb894 ("tracing: Use tracing error_log with probe events") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-03-30Merge tag 'modules-6.15-rc1' of ↵Linus Torvalds1-6/+3
git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux Pull modules updates from Petr Pavlu: - Use RCU instead of RCU-sched The mix of rcu_read_lock(), rcu_read_lock_sched() and preempt_disable() in the module code and its users has been replaced with just rcu_read_lock() - The rest of changes are smaller fixes and updates * tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (32 commits) MAINTAINERS: Update the MODULE SUPPORT section module: Remove unnecessary size argument when calling strscpy() module: Replace deprecated strncpy() with strscpy() params: Annotate struct module_param_attrs with __counted_by() bug: Use RCU instead RCU-sched to protect module_bug_list. static_call: Use RCU in all users of __module_text_address(). kprobes: Use RCU in all users of __module_text_address(). bpf: Use RCU in all users of __module_text_address(). jump_label: Use RCU in all users of __module_text_address(). jump_label: Use RCU in all users of __module_address(). x86: Use RCU in all users of __module_address(). cfi: Use RCU while invoking __module_address(). powerpc/ftrace: Use RCU in all users of __module_text_address(). LoongArch: ftrace: Use RCU in all users of __module_text_address(). LoongArch/orc: Use RCU in all users of __module_address(). arm64: module: Use RCU in all users of __module_text_address(). ARM: module: Use RCU in all users of __module_text_address(). module: Use RCU in all users of __module_text_address(). module: Use RCU in all users of __module_address(). module: Use RCU in search_module_extables(). ...
2025-03-27tracing: probe-events: Log error for exceeding the number of argumentsMasami Hiramatsu (Google)1-1/+4
Add error message when the number of arguments exceeds the limitation. Link: https://lore.kernel.org/all/174055075075.4079315.10916648136898316476.stgit@mhiramat.tok.corp.google.com/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-03-10module: Use RCU in find_module_all().Sebastian Andrzej Siewior1-6/+3
The modules list and module::kallsyms can be accessed under RCU assumption. Remove module_assert_mutex_or_preempt() from find_module_all() so it can be used under RCU protection without warnings. Update its callers to use RCU protection instead of preempt_disable(). Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-trace-kernel@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250108090457.512198-7-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-10tracing/kprobes: Simplify __trace_kprobe_create() by removing gotosMasami Hiramatsu (Google)1-48/+49
Simplify __trace_kprobe_create() by removing gotos. Link: https://lore.kernel.org/all/173643301102.1514810.6149004416601259466.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-10tracing: Use __free() for kprobe events to cleanupMasami Hiramatsu (Google)1-33/+29
Use __free() in trace_kprobe.c to cleanup code. Link: https://lore.kernel.org/all/173643299989.1514810.2924926552980462072.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-10tracing/kprobe: Adopt guard() and scoped_guard()Masami Hiramatsu (Google)1-12/+6
Use guard() or scoped_guard() in kprobe events for critical sections rather than discrete lock/unlock pairs. Link: https://lore.kernel.org/all/173289888883.73724.6586200652276577583.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-01-10tracing/kprobes: Fix to free objects when failed to copy a symbolMasami Hiramatsu (Google)1-2/+4
In __trace_kprobe_create(), if something fails it must goto error block to free objects. But when strdup() a symbol, it returns without that. Fix it to goto the error block to free objects correctly. Link: https://lore.kernel.org/all/173643297743.1514810.2408159540454241947.stgit@devnote2/ Fixes: 6212dd29683e ("tracing/kprobes: Use dyn_event framework for kprobe events") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-24tracing/kprobe: Make trace_kprobe's module callback called after jump_label ↵Masami Hiramatsu (Google)1-1/+1
update Make sure the trace_kprobe's module notifer callback function is called after jump_label's callback is called. Since the trace_kprobe's callback eventually checks jump_label address during registering new kprobe on the loading module, jump_label must be updated before this registration happens. Link: https://lore.kernel.org/all/173387585556.995044.3157941002975446119.stgit@devnote2/ Fixes: 614243181050 ("tracing/kprobes: Support module init function probing") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-23tracing/probes: Fix MAX_TRACE_ARGS limit handlingMikel Rychliski1-1/+5
When creating a trace_probe we would set nr_args prior to truncating the arguments to MAX_TRACE_ARGS. However, we would only initialize arguments up to the limit. This caused invalid memory access when attempting to set up probes with more than 128 fetchargs. BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014 RIP: 0010:__set_print_fmt+0x134/0x330 Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return an error when there are too many arguments instead of silently truncating. Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/ Fixes: 035ba76014c0 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init") Signed-off-by: Mikel Rychliski <mikel@mikelr.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-07-10tracing/kprobes: Fix build error when find_module() is not availableMasami Hiramatsu (Google)1-6/+19
The kernel test robot reported that the find_module() is not available if CONFIG_MODULES=n. Fix this error by hiding find_modules() in #ifdef CONFIG_MODULES with related rcu locks as try_module_get_by_name(). Link: https://lore.kernel.org/all/172056819167.201571.250053007194508038.stgit@devnote2/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202407070744.RcLkn8sq-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202407070917.VVUCBlaS-lkp@intel.com/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-07-06tracing/kprobes: Add symbol counting check when module loadsMasami Hiramatsu (Google)1-44/+81
Currently, kprobe event checks whether the target symbol name is unique or not, so that it does not put a probe on an unexpected place. But this skips the check if the target is on a module because the module may not be loaded. To fix this issue, this patch checks the number of probe target symbols in a target module when the module is loaded. If the probe is not on the unique name symbols in the module, it will be rejected at that point. Note that the symbol which has a unique name in the target module, it will be accepted even if there are same-name symbols in the kernel or other modules, Link: https://lore.kernel.org/all/172016348553.99543.2834679315611882137.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12tracing/kprobe: Remove cleanup code unrelated to selftestMasami Hiramatsu (Google)1-4/+0
This cleanup all kprobe events code is not related to the selftest itself, and it can fail by the reason unrelated to this test. If the test is successful, the generated events are cleaned up. And if not, we cannot guarantee that the kprobe events will work correctly. So, anyway, there is no need to clean it up. Link: https://lore.kernel.org/all/171811265627.85078.16897867213512435822.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12tracing/kprobe: Integrate test warnings into WARN_ONCEMasami Hiramatsu (Google)1-35/+19
Cleanup the redundant WARN_ON_ONCE(cond) + pr_warn(msg) into WARN_ONCE(cond, msg). Also add some WARN_ONCE() for hitcount check. These WARN_ONCE() errors makes it easy to handle errors from ktest. Link: https://lore.kernel.org/all/171811264685.85078.8068819097047430463.stgit@devnote2/ Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-17Merge tag 'probes-v6.10' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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
2024-05-14kprobes: remove dependency on CONFIG_MODULESMike Rapoport (IBM)1-1/+19
kprobes depended on CONFIG_MODULES because it has to allocate memory for code. Since code allocations are now implemented with execmem, kprobes can be enabled in non-modular kernels. Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the dependency of CONFIG_KPROBES on CONFIG_MODULES. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> [mcgrof: rebase in light of NEED_TASKS_RCU ] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-01tracing/probes: support '%pd' type for print struct dentry's nameYe Bin1-0/+6
During fault locating, the file name needs to be printed based on the dentry address. The offset needs to be calculated each time, which is troublesome. Similar to printk, kprobe support print type '%pd' for print dentry's name. For example "name=$arg1:%pd" casts the `$arg1` as (struct dentry *), dereferences the "d_name.name" field and stores it to "name" argument as a kernel string. Here is an example: [tracing]# echo 'p:testprobe dput name=$arg1:%pd' > kprobe_events [tracing]# echo 1 > events/kprobes/testprobe/enable [tracing]# grep -q "1" events/kprobes/testprobe/enable [tracing]# echo 0 > events/kprobes/testprobe/enable [tracing]# cat trace | grep "enable" bash-14844 [002] ..... 16912.889543: testprobe: (dput+0x4/0x30) name="enable" grep-15389 [003] ..... 16922.834182: testprobe: (dput+0x4/0x30) name="enable" grep-15389 [003] ..... 16922.836103: testprobe: (dput+0x4/0x30) name="enable" bash-14844 [001] ..... 16931.820909: testprobe: (dput+0x4/0x30) name="enable" Note that this expects the given argument (e.g. $arg1) is an address of struct dentry. User must ensure it. Link: https://lore.kernel.org/all/20240322064308.284457-2-yebin10@huawei.com/ Signed-off-by: Ye Bin <yebin10@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-03-07tracing/probes: Support $argN in return probe (kprobe and fprobe)Masami Hiramatsu (Google)1-10/+46
Support accessing $argN in the return probe events. This will help users to record entry data in function return (exit) event for simplfing the function entry/exit information in one event, and record the result values (e.g. allocated object/initialized object) at function exit. For example, if we have a function `int init_foo(struct foo *obj, int param)` sometimes we want to check how `obj` is initialized. In such case, we can define a new return event like below; # echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events Thus it records the function parameter `param` and its result `obj->field1` (the dereference will be done in the function exit timing) value at once. This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF is enabled, we can trace both function parameters and the return value by following command. # echo 'f target_function%return $arg* $retval' >> dynamic_events Link: https://lore.kernel.org/all/170952365552.229804.224112990211602895.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-03-07tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_initMasami Hiramatsu (Google)1-1/+1
Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init(). Without this change, there is no way to get the number of trace_probe arguments while parsing it. This is a cleanup, so the behavior is not changed. Link: https://lore.kernel.org/all/170952363585.229804.13060759900346411951.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-12-17trace/kprobe: Display the actual notrace function when rejecting a probeNaveen N Rao1-2/+2
Trying to probe update_sd_lb_stats() using perf results in the below message in the kernel log: trace_kprobe: Could not probe notrace function _text This is because 'perf probe' specifies the kprobe location as an offset from '_text': $ sudo perf probe -D update_sd_lb_stats p:probe/update_sd_lb_stats _text+1830728 However, the error message is misleading and doesn't help convey the actual notrace function that is being probed. Fix this by looking up the actual function name that is being probed. With this fix, we now get the below message in the kernel log: trace_kprobe: Could not probe notrace function update_sd_lb_stats.constprop.0 Link: https://lore.kernel.org/all/20231214051702.1687300-1-naveen@kernel.org/ Signed-off-by: Naveen N Rao <naveen@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-11-11tracing/kprobes: Fix the order of argument descriptionsYujie Liu1-1/+1
The order of descriptions should be consistent with the argument list of the function, so "kretprobe" should be the second one. int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe, const char *name, const char *loc, ...) Link: https://lore.kernel.org/all/20231031041305.3363712-1-yujie.liu@intel.com/ Fixes: 2a588dd1d5d6 ("tracing: Add kprobe event command generation functions") Suggested-by: Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by: Yujie Liu <yujie.liu@intel.com> Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-31Merge tag 'net-next-6.7' of ↵Linus Torvalds1-3/+11
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core & protocols: - Support usec resolution of TCP timestamps, enabled selectively by a route attribute. - Defer regular TCP ACK while processing socket backlog, try to send a cumulative ACK at the end. Increase single TCP flow performance on a 200Gbit NIC by 20% (100Gbit -> 120Gbit). - The Fair Queuing (FQ) packet scheduler: - add built-in 3 band prio / WRR scheduling - support bypass if the qdisc is mostly idle (5% speed up for TCP RR) - improve inactive flow reporting - optimize the layout of structures for better cache locality - Support TCP Authentication Option (RFC 5925, TCP-AO), a more modern replacement for the old MD5 option. - Add more retransmission timeout (RTO) related statistics to TCP_INFO. - Support sending fragmented skbs over vsock sockets. - Make sure we send SIGPIPE for vsock sockets if socket was shutdown(). - Add sysctl for ignoring lower limit on lifetime in Router Advertisement PIO, based on an in-progress IETF draft. - Add sysctl to control activation of TCP ping-pong mode. - Add sysctl to make connection timeout in MPTCP configurable. - Support rcvlowat and notsent_lowat on MPTCP sockets, to help apps limit the number of wakeups. - Support netlink GET for MDB (multicast forwarding), allowing user space to request a single MDB entry instead of dumping the entire table. - Support selective FDB flushing in the VXLAN tunnel driver. - Allow limiting learned FDB entries in bridges, prevent OOM attacks. - Allow controlling via configfs netconsole targets which were created via the kernel cmdline at boot, rather than via configfs at runtime. - Support multiple PTP timestamp event queue readers with different filters. - MCTP over I3C. BPF: - Add new veth-like netdevice where BPF program defines the logic of the xmit routine. It can operate in L3 and L2 mode. - Support exceptions - allow asserting conditions which should never be true but are hard for the verifier to infer. With some extra flexibility around handling of the exit / failure: https://lwn.net/Articles/938435/ - Add support for local per-cpu kptr, allow allocating and storing per-cpu objects in maps. Access to those objects operates on the value for the current CPU. This allows to deprecate local one-off implementations of per-CPU storage like BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE maps. - Extend cgroup BPF sockaddr hooks for UNIX sockets. The use case is for systemd to re-implement the LogNamespace feature which allows running multiple instances of systemd-journald to process the logs of different services. - Enable open-coded task_vma iteration, after maple tree conversion made it hard to directly walk VMAs in tracing programs. - Add open-coded task, css_task and css iterator support. One of the use cases is customizable OOM victim selection via BPF. - Allow source address selection with bpf_*_fib_lookup(). - Add ability to pin BPF timer to the current CPU. - Prevent creation of infinite loops by combining tail calls and fentry/fexit programs. - Add missed stats for kprobes to retrieve the number of missed kprobe executions and subsequent executions of BPF programs. - Inherit system settings for CPU security mitigations. - Add BPF v4 CPU instruction support for arm32 and s390x. Changes to common code: - overflow: add DEFINE_FLEX() for on-stack definition of structs with flexible array members. - Process doc update with more guidance for reviewers. Driver API: - Simplify locking in WiFi (cfg80211 and mac80211 layers), use wiphy mutex in most places and remove a lot of smaller locks. - Create a common DPLL configuration API. Allow configuring and querying state of PLL circuits used for clock syntonization, in network time distribution. - Unify fragmented and full page allocation APIs in page pool code. Let drivers be ignorant of PAGE_SIZE. - Rework PHY state machine to avoid races with calls to phy_stop(). - Notify DSA drivers of MAC address changes on user ports, improve correctness of offloads which depend on matching port MAC addresses. - Allow antenna control on injected WiFi frames. - Reduce the number of variants of napi_schedule(). - Simplify error handling when composing devlink health messages. Misc: - A lot of KCSAN data race "fixes", from Eric. - A lot of __counted_by() annotations, from Kees. - A lot of strncpy -> strscpy and printf format fixes. - Replace master/slave terminology with conduit/user in DSA drivers. - Handful of KUnit tests for netdev and WiFi core. Removed: - AppleTalk COPS. - AppleTalk ipddp. - TI AR7 CPMAC Ethernet driver. Drivers: - Ethernet high-speed NICs: - Intel (100G, ice, idpf): - add a driver for the Intel E2000 IPUs - make CRC/FCS stripping configurable - cross-timestamping for E823 devices - basic support for E830 devices - use aux-bus for managing client drivers - i40e: report firmware versions via devlink - nVidia/Mellanox: - support 4-port NICs - increase max number of channels to 256 - optimize / parallelize SF creation flow - Broadcom (bnxt): - enhance NIC temperature reporting - support PAM4 speeds and lane configuration - Marvell OcteonTX2: - PTP pulse-per-second output support - enable hardware timestamping for VFs - Solarflare/AMD: - conntrack NAT offload and offload for tunnels - Wangxun (ngbe/txgbe): - expose HW statistics - Pensando/AMD: - support PCI level reset - narrow down the condition under which skbs are linearized - Netronome/Corigine (nfp): - support CHACHA20-POLY1305 crypto in IPsec offload - Ethernet NICs embedded, slower, virtual: - Synopsys (stmmac): - add Loongson-1 SoC support - enable use of HW queues with no offload capabilities - enable PPS input support on all 5 channels - increase TX coalesce timer to 5ms - RealTek USB (r8152): improve efficiency of Rx by using GRO frags - xen: support SW packet timestamping - add drivers for implementations based on TI's PRUSS (AM64x EVM) - nVidia/Mellanox Ethernet datacenter switches: - avoid poor HW resource use on Spectrum-4 by better block selection for IPv6 multicast forwarding and ordering of blocks in ACL region - Ethernet embedded switches: - Microchip: - support configuring the drive strength for EMI compliance - ksz9477: partial ACL support - ksz9477: HSR offload - ksz9477: Wake on LAN - Realtek: - rtl8366rb: respect device tree config of the CPU port - Ethernet PHYs: - support Broadcom BCM5221 PHYs - TI dp83867: support hardware LED blinking - CAN: - add support for Linux-PHY based CAN transceivers - at91_can: clean up and use rx-offload helpers - WiFi: - MediaTek (mt76): - new sub-driver for mt7925 USB/PCIe devices - HW wireless <> Ethernet bridging in MT7988 chips - mt7603/mt7628 stability improvements - Qualcomm (ath12k): - WCN7850: - enable 320 MHz channels in 6 GHz band - hardware rfkill support - enable IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS to make scan faster - read board data variant name from SMBIOS - QCN9274: mesh support - RealTek (rtw89): - TDMA-based multi-channel concurrency (MCC) - Silicon Labs (wfx): - Remain-On-Channel (ROC) support - Bluetooth: - ISO: many improvements for broadcast support - mark BCM4378/BCM4387 as BROKEN_LE_CODED - add support for QCA2066 - btmtksdio: enable Bluetooth wakeup from suspend" * tag 'net-next-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1816 commits) net: pcs: xpcs: Add 2500BASE-X case in get state for XPCS drivers net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos() net: mana: Use xdp_set_features_flag instead of direct assignment vxlan: Cleanup IFLA_VXLAN_PORT_RANGE entry in vxlan_get_size() iavf: delete the iavf client interface iavf: add a common function for undoing the interrupt scheme iavf: use unregister_netdev iavf: rely on netdev's own registered state iavf: fix the waiting time for initial reset iavf: in iavf_down, don't queue watchdog_task if comms failed iavf: simplify mutex_trylock+sleep loops iavf: fix comments about old bit locks doc/netlink: Update schema to support cmd-cnt-name and cmd-max-name tools: ynl: introduce option to process unknown attributes or types ipvlan: properly track tx_errors netdevsim: Block until all devices are released nfp: using napi_build_skb() to replace build_skb() net: dsa: microchip: ksz9477: Fix spelling mistake "Enery" -> "Energy" net: dsa: microchip: Ensure Stable PME Pin State for Wake-on-LAN net: dsa: microchip: Refactor switch shutdown routine for WoL preparation ...
2023-10-28tracing/kprobes: Fix symbol counting logic by looking at modules as wellAndrii Nakryiko1-4/+20
Recent changes to count number of matching symbols when creating a kprobe event failed to take into account kernel modules. As such, it breaks kprobes on kernel module symbols, by assuming there is no match. Fix this my calling module_kallsyms_on_each_symbol() in addition to kallsyms_on_each_match_symbol() to perform a proper counting. Link: https://lore.kernel.org/all/20231027233126.2073148-1-andrii@kernel.org/ Cc: Francis Laniel <flaniel@linux.microsoft.com> Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Fixes: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <song@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-27tracing/kprobes: Fix the description of variable length argumentsYujie Liu1-2/+2
Fix the following kernel-doc warnings: kernel/trace/trace_kprobe.c:1029: warning: Excess function parameter 'args' description in '__kprobe_event_gen_cmd_start' kernel/trace/trace_kprobe.c:1097: warning: Excess function parameter 'args' description in '__kprobe_event_add_fields' Refer to the usage of variable length arguments elsewhere in the kernel code, "@..." is the proper way to express it in the description. Link: https://lore.kernel.org/all/20231027041315.2613166-1-yujie.liu@intel.com/ Fixes: 2a588dd1d5d6 ("tracing: Add kprobe event command generation functions") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202310190437.paI6LYJF-lkp@intel.com/ Signed-off-by: Yujie Liu <yujie.liu@intel.com> Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+63
Cross-merge networking fixes after downstream PR. Conflicts: net/mac80211/rx.c 91535613b609 ("wifi: mac80211: don't drop all unprotected public action frames") 6c02fab72429 ("wifi: mac80211: split ieee80211_drop_unencrypted_mgmt() return value") Adjacent changes: drivers/net/ethernet/apm/xgene/xgene_enet_main.c 61471264c018 ("net: ethernet: apm: Convert to platform remove callback returning void") d2ca43f30611 ("net: xgene: Fix unused xgene_enet_of_match warning for !CONFIG_OF") net/vmw_vsock/virtio_transport.c 64c99d2d6ada ("vsock/virtio: support to send non-linear skb") 53b08c498515 ("vsock/virtio: initialize the_virtio_vsock before using VQs") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-20tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbolsFrancis Laniel1-0/+63
When a kprobe is attached to a function that's name is not unique (is static and shares the name with other functions in the kernel), the kprobe is attached to the first function it finds. This is a bug as the function that it is attaching to is not necessarily the one that the user wants to attach to. Instead of blindly picking a function to attach to what is ambiguous, error with EADDRNOTAVAIL to let the user know that this function is not unique, and that the user must use another unique function with an address offset to get to the function they want to attach to. Link: https://lore.kernel.org/all/20231020104250.9537-2-flaniel@linux.microsoft.com/ Cc: stable@vger.kernel.org Fixes: 413d37d1eb69 ("tracing: Add kprobe-based event tracer") Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Francis Laniel <flaniel@linux.microsoft.com> Link: https://lore.kernel.org/lkml/20230819101105.b0c104ae4494a7d1f2eea742@kernel.org/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-09-25bpf: Add missed value to kprobe perf link infoJiri Olsa1-3/+11
Add missed value to kprobe attached through perf link info to hold the stats of missed kprobe handler execution. The kprobe's missed counter gets incremented when kprobe handler is not executed due to another kprobe running on the same cpu. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230920213145.1941596-4-jolsa@kernel.org
2023-09-02Merge tag 'probes-v6.6' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes updates from Masami Hiramatsu: - kprobes: use struct_size() for variable size kretprobe_instance data structure. - eprobe: Simplify trace_eprobe list iteration. - probe events: Data structure field access support on BTF argument. - Update BTF argument support on the functions in the kernel loadable modules (only loaded modules are supported). - Move generic BTF access function (search function prototype and get function parameters) to a separated file. - Add a function to search a member of data structure in BTF. - Support accessing BTF data structure member from probe args by C-like arrow('->') and dot('.') operators. e.g. 't sched_switch next=next->pid vruntime=next->se.vruntime' - Support accessing BTF data structure member from $retval. e.g. 'f getname_flags%return +0($retval->name):string' - Add string type checking if BTF type info is available. This will reject if user specify ":string" type for non "char pointer" type. - Automatically assume the fprobe event as a function return event if $retval is used. - selftests/ftrace: Add BTF data field access test cases. - Documentation: Update fprobe event example with BTF data field. * tag 'probes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: Documentation: tracing: Update fprobe event example with BTF field selftests/ftrace: Add BTF fields access testcases tracing/fprobe-event: Assume fprobe is a return event by $retval tracing/probes: Add string type check with BTF tracing/probes: Support BTF field access from $retval tracing/probes: Support BTF based data structure field access tracing/probes: Add a function to search a member of a struct/union tracing/probes: Move finding func-proto API and getting func-param API to trace_btf tracing/probes: Support BTF argument on module functions tracing/eprobe: Iterate trace_eprobe directly kernel: kprobes: Use struct_size()
2023-08-23tracing/probes: Support BTF argument on module functionsMasami Hiramatsu (Google)1-0/+1
Since the btf returned from bpf_get_btf_vmlinux() only covers functions in the vmlinux, BTF argument is not available on the functions in the modules. Use bpf_find_btf_id() instead of bpf_get_btf_vmlinux()+btf_find_name_kind() so that BTF argument can find the correct struct btf and btf_type in it. With this fix, fprobe events can use `$arg*` on module functions as below # grep nf_log_ip_packet /proc/kallsyms ffffffffa0005c00 t nf_log_ip_packet [nf_log_syslog] ffffffffa0005bf0 t __pfx_nf_log_ip_packet [nf_log_syslog] # echo 'f nf_log_ip_packet $arg*' > dynamic_events # cat dynamic_events f:fprobes/nf_log_ip_packet__entry nf_log_ip_packet net=net pf=pf hooknum=hooknum skb=skb in=in out=out loginfo=loginfo prefix=prefix To support the module's btf which is removable, the struct btf needs to be ref-counted. So this also records the btf in the traceprobe_parse_context and returns the refcount when the parse has done. Link: https://lore.kernel.org/all/169272154223.160970.3507930084247934031.stgit@devnote2/ Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-07-13Merge tag 'for-netdev' of ↵Jakub Kicinski1-9/+4
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Alexei Starovoitov says: ==================== pull-request: bpf-next 2023-07-13 We've added 67 non-merge commits during the last 15 day(s) which contain a total of 106 files changed, 4444 insertions(+), 619 deletions(-). The main changes are: 1) Fix bpftool build in presence of stale vmlinux.h, from Alexander Lobakin. 2) Introduce bpf_me_mcache_free_rcu() and fix OOM under stress, from Alexei Starovoitov. 3) Teach verifier actual bounds of bpf_get_smp_processor_id() and fix perf+libbpf issue related to custom section handling, from Andrii Nakryiko. 4) Introduce bpf map element count, from Anton Protopopov. 5) Check skb ownership against full socket, from Kui-Feng Lee. 6) Support for up to 12 arguments in BPF trampoline, from Menglong Dong. 7) Export rcu_request_urgent_qs_task, from Paul E. McKenney. 8) Fix BTF walking of unions, from Yafang Shao. 9) Extend link_info for kprobe_multi and perf_event links, from Yafang Shao. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (67 commits) selftests/bpf: Add selftest for PTR_UNTRUSTED bpf: Fix an error in verifying a field in a union selftests/bpf: Add selftests for nested_trust bpf: Fix an error around PTR_UNTRUSTED selftests/bpf: add testcase for TRACING with 6+ arguments bpf, x86: allow function arguments up to 12 for TRACING bpf, x86: save/restore regs with BPF_DW size bpftool: Use "fallthrough;" keyword instead of comments bpf: Add object leak check. bpf: Convert bpf_cpumask to bpf_mem_cache_free_rcu. bpf: Introduce bpf_mem_free_rcu() similar to kfree_rcu(). selftests/bpf: Improve test coverage of bpf_mem_alloc. rcu: Export rcu_request_urgent_qs_task() bpf: Allow reuse from waiting_for_gp_ttrace list. bpf: Add a hint to allocated objects. bpf: Change bpf_mem_cache draining process. bpf: Further refactor alloc_bulk(). bpf: Factor out inc/dec of active flag into helpers. bpf: Refactor alloc_bulk(). bpf: Let free_all() return the number of freed elements. ... ==================== Link: https://lore.kernel.org/r/20230714020910.80794-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-11bpf: Expose symbol's respective addressYafang Shao1-12/+4
Since different symbols can share the same name, it is insufficient to only expose the symbol name. It is essential to also expose the symbol address so that users can accurately identify which one is being probed. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/202