user/sven/linux.git/kernel/trace/trace_kprobe.c, branch v4.19.111

tracing/kprobe: Check whether the non-suffixed symbol is notrace

2019-12-31T15:36:02Z

[ Upstream commit c7411a1a126f649be71526a36d4afac9e5aefa13 ] Check whether the non-suffixed symbol is notrace, since suffixed symbols are generated by the compilers for optimization. Based on these suffixed symbols, notrace check might not work because some of them are just a partial code of the original function. (e.g. cold-cache (unlikely) code is separated from original function as FUNCTION.cold.XX) For example, without this fix, # echo p device_add.cold.67 > /sys/kernel/debug/tracing/kprobe_events sh: write error: Invalid argument # cat /sys/kernel/debug/tracing/error_log [ 135.491035] trace_kprobe: error: Failed to register probe event Command: p device_add.cold.67 ^ # dmesg | tail -n 1 [ 135.488599] trace_kprobe: Could not probe notrace function device_add.cold.67 With this, # echo p device_add.cold.66 > /sys/kernel/debug/tracing/kprobe_events # cat /sys/kernel/debug/kprobes/list ffffffff81599de9 k device_add.cold.66+0x0 [DISABLED] Actually, kprobe blacklist already did similar thing, see within_kprobe_blacklist(). Link: http://lkml.kernel.org/r/157233790394.6706.18243942030937189679.stgit@devnote2 Fixes: 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing/kprobes: Check the probe on unloaded module correctly

2018-11-21T08:19:09Z

[ Upstream commit 59158ec4aef7d44be51a6f3e7e17fc64c32604eb ] Current kprobe event doesn't checks correctly whether the given event is on unloaded module or not. It just checks the event has ":" in the name. That is not enough because if we define a probe on non-exist symbol on loaded module, it allows to define that (with warning message) To ensure it correctly, this searches the module name on loaded module list and only if there is not, it allows to define it. (this event will be available when the target module is loaded) Link: http://lkml.kernel.org/r/153547309528.26502.8300278470528281328.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-08-23T20:07:00Z

Pull tracing fixes from Steven Rostedt: "Masami found an off by one bug in the code that keeps "notrace" functions from being traced by kprobes. During my testing, I found that there's places that we may want to add kprobes to notrace, thus we may end up changing this code before 4.19 is released. The history behind this change is that we found that adding kprobes to various notrace functions caused the kernel to crashed. We took the safe route and decided not to allow kprobes to trace any notrace function. But because notrace is added to functions that just cause weird side effects to the function tracer, but are still safe, preventing kprobes for all notrace functios may be too much of a big hammer. One such place is __schedule() is marked notrace, to keep function tracer from doing strange recursive loops when it gets traced with NEED_RESCHED set. With this change, one can not add kprobes to the scheduler. Masami also added code to use gcov on ftrace" * tag 'trace-v4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/kprobes: Fix to check notrace function with correct range tracing: Allow gcov profiling on only ftrace subsystem

tracing/kprobes: Fix to check notrace function with correct range

2018-08-21T13:41:12Z

Fix within_notrace_func() to check notrace function correctly. Since the ftrace_location_range(start, end) function checks the range inclusively (start <= ftrace-loc <= end), the end address must not include the entry address of next function. However, within_notrace_func() uses kallsyms_lookup_size_offset() to get the function size and calculate the end address from adding the size to the entry address. This means the end address is the entry address of the next function. In the result, within_notrace_func() fails to find notrace function if the next function of the target function is ftraced. Let's subtract 1 from the end address so that ftrace_location_range() can check it correctly. Link: http://lkml.kernel.org/r/153485669706.16611.17726752296213785504.stgit@devbox Fixes: commit 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function") Reported-by: Michael Rodin Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-08-21T01:32:00Z

Pull tracing updates from Steven Rostedt: - Restructure of lockdep and latency tracers This is the biggest change. Joel Fernandes restructured the hooks from irqs and preemption disabling and enabling. He got rid of a lot of the preprocessor #ifdef mess that they caused. He turned both lockdep and the latency tracers to use trace events inserted in the preempt/irqs disabling paths. But unfortunately, these started to cause issues in corner cases. Thus, parts of the code was reverted back to where lockdep and the latency tracers just get called directly (without using the trace events). But because the original change cleaned up the code very nicely we kept that, as well as the trace events for preempt and irqs disabling, but they are limited to not being called in NMIs. - Have trace events use SRCU for "rcu idle" calls. This was required for the preempt/irqs off trace events. But it also had to not allow them to be called in NMI context. Waiting till Paul makes an NMI safe SRCU API. - New notrace SRCU API to allow trace events to use SRCU. - Addition of mcount-nop option support - SPDX headers replacing GPL templates. - Various other fixes and clean ups. - Some fixes are marked for stable, but were not fully tested before the merge window opened. * tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix SPDX format headers to use C++ style comments tracing: Add SPDX License format tags to tracing files tracing: Add SPDX License format to bpf_trace.c blktrace: Add SPDX License format header s390/ftrace: Add -mfentry and -mnop-mcount support tracing: Add -mcount-nop option support tracing: Avoid calling cc-option -mrecord-mcount for every Makefile tracing: Handle CC_FLAGS_FTRACE more accurately Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() Uprobes: Simplify uprobe_register() body tracepoints: Free early tracepoints after RCU is initialized uprobes: Use synchronize_rcu() not synchronize_sched() tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister() ftrace: Remove unused pointer ftrace_swapper_pid tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing/irqsoff: Handle preempt_count for different configs tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing: irqsoff: Account for additional preempt_disable trace: Use rcu_dereference_raw for hooks from trace-event subsystem tracing/kprobes: Fix within_notrace_func() to check only notrace functions ...

tracing: Add SPDX License format tags to tracing files

2018-08-16T23:08:06Z

Add the SPDX License header to ease license compliance management. Signed-off-by: Steven Rostedt (VMware)

tracing/kprobes: Fix within_notrace_func() to check only notrace functions

2018-08-02T16:34:41Z

Fix within_notrace_func() to check only notrace functions and to ignore the kprobe-event which can not solve symbol addresses. within_notrace_func() returns true if the given kprobe events probe point seems to be out-of-range. But that is not the correct place to check for it, it should be done in kprobes afterwards. kprobe-events allow users to define a probe point on "currently unloaded module" so that it can trace the event during module load. In this case, the user will put a probe on a symbol which is not in kallsyms yet and it hits the within_notrace_func(). As a result, kprobe-events always refuses if user defines a probe on a "currenly unloaded module". Fixes: commit 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function") Link: http://lkml.kernel.org/r/153319624799.29007.13604430345640129926.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

Merge branch 'perf/urgent' into perf/core, to pick up fixes

2018-08-02T07:59:20Z

Signed-off-by: Ingo Molnar

selftest/ftrace: Move kprobe selftest function to separate compile unit

2018-07-30T22:41:04Z

Move selftest function to its own compile unit so it can be compiled with the ftrace cflags (CC_FLAGS_FTRACE) allowing it to be probed during the ftrace startup tests. Link: http://lkml.kernel.org/r/153294604271.32740.16490677128630177030.stgit@devbox Signed-off-by: Francis Deslauriers Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: kprobes: Prohibit probing on notrace function

2018-07-30T22:28:52Z

Prohibit kprobe-events probing on notrace functions. Since probing on a notrace function can cause a recursive event call. In most cases those are just skipped, but in some cases it falls into an infinite recursive call. This protection can be disabled by the kconfig CONFIG_KPROBE_EVENTS_ON_NOTRACE=y, but it is highly recommended to keep it "n" for normal kernel builds. Note that this is only available if "kprobes on ftrace" has been implemented on the target arch and CONFIG_KPROBES_ON_FTRACE=y. Link: http://lkml.kernel.org/r/153294601436.32740.10557881188933661239.stgit@devbox Signed-off-by: Masami Hiramatsu Tested-by: Francis Deslauriers [ Slight grammar and spelling fixes ] Signed-off-by: Steven Rostedt (VMware)