wireguard-linux/kernel/trace/trace_kprobe.c, branch jd/bump-compilers

tracing/kprobes: Fix build error when find_module() is not available

2024-07-10T00:47:00Z

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 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)

tracing/kprobes: Add symbol counting check when module loads

2024-07-06T00:27:47Z

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) Reviewed-by: Steven Rostedt (Google)

tracing/kprobe: Remove cleanup code unrelated to selftest

2024-06-11T23:46:00Z

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) Reviewed-by: Steven Rostedt (Google)

tracing/kprobe: Integrate test warnings into WARN_ONCE

2024-06-11T23:44:44Z

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 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

kprobes: remove dependency on CONFIG_MODULES

2024-05-14T07:35:06Z

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) Acked-by: Masami Hiramatsu (Google) [mcgrof: rebase in light of NEED_TASKS_RCU ] Signed-off-by: Luis Chamberlain

tracing/probes: support '%pd' type for print struct dentry's name

2024-05-01T14:18:47Z

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 Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google)

tracing/probes: Support $argN in return probe (kprobe and fprobe)

2024-03-06T15:27:34Z

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)

tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init

2024-03-06T15:27:15Z

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)

trace/kprobe: Display the actual notrace function when rejecting a probe

2023-12-17T07:28:54Z

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 Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google)