user/sven/linux.git/kernel/trace/trace_event_perf.c, branch v4.4.166

treewide: Remove old email address

2015-11-23T08:44:58Z

There were still a number of references to my old Red Hat email address in the kernel source. Remove these while keeping the Red Hat copyright notices intact. Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Signed-off-by: Ingo Molnar

tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}

2015-05-13T18:06:10Z

The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structures ftrace_event_call and ftrace_event_class have nothing to do with the function hooks, and are really trace_event structures. Rename ftrace_event_* to trace_event_*. Signed-off-by: Steven Rostedt

perf: Avoid horrible stack usage

2015-01-14T14:11:45Z

Both Linus (most recent) and Steve (a while ago) reported that perf related callbacks have massive stack bloat. The problem is that software events need a pt_regs in order to properly report the event location and unwind stack. And because we could not assume one was present we allocated one on stack and filled it with minimal bits required for operation. Now, pt_regs is quite large, so this is undesirable. Furthermore it turns out that most sites actually have a pt_regs pointer available, making this even more onerous, as the stack space is pointless waste. This patch addresses the problem by observing that software events have well defined nesting semantics, therefore we can use static per-cpu storage instead of on-stack. Linus made the further observation that all but the scheduler callers of perf_sw_event() have a pt_regs available, so we change the regular perf_sw_event() to require a valid pt_regs (where it used to be optional) and add perf_sw_event_sched() for the scheduler. We have a scheduler specific call instead of a more generic _noregs() like construct because we can assume non-recursion from the scheduler and thereby simplify the code further (_noregs would have to put the recursion context call inline in order to assertain which __perf_regs element to use). One last note on the implementation of perf_trace_buf_prepare(); we allow .regs = NULL for those cases where we already have a pt_regs pointer available and do not need another. Reported-by: Linus Torvalds Reported-by: Steven Rostedt Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Javi Merino Cc: Linus Torvalds Cc: Mathieu Desnoyers Cc: Oleg Nesterov Cc: Paul Mackerras Cc: Petr Mladek Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vaibhav Nagarnaik Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

perf: Check permission only for parent tracepoint event

2014-07-28T08:01:38Z

There's no need to check cloned event's permission once the parent was already checked. Also the code is checking 'current' process permissions, which is not owner process for cloned events, thus could end up with wrong permission check result. Reported-by: Alexander Yarygin Tested-by: Alexander Yarygin Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Corey Ashford Cc: Frederic Weisbecker Cc: Paul Mackerras Cc: Linus Torvalds Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1405079782-8139-1-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar

kprobes, ftrace: Use NOKPROBE_SYMBOL macro in ftrace

2014-04-24T08:26:39Z

Use NOKPROBE_SYMBOL macro to protect functions from kprobes instead of __kprobes annotation in ftrace. This applies nokprobe_inline annotation for some cases, because NOKPROBE_SYMBOL() will inhibit inlining by referring the symbol address. Signed-off-by: Masami Hiramatsu Cc: Frederic Weisbecker Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20140417081828.26341.55152.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar

perf: Disallow user-space stack dumps for function trace events

2014-03-11T10:57:58Z

Recent issues with user space callchains processing within page fault handler tracing showed as Peter said 'there's just too much fail surface'. The user space stack dump is just another source of the this issue. Related list discussions: http://marc.info/?t=139302086500001&r=1&w=2 http://marc.info/?t=139301437300003&r=1&w=2 Suggested-by: Peter Zijlstra Signed-off-by: Jiri Olsa Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Vince Weaver Cc: Steven Rostedt Cc: Paul Mackerras Cc: H. Peter Anvin Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1393775800-13524-3-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar

perf: Disallow user-space callchains for function trace events

2014-03-11T10:57:57Z

Recent issues with user space callchains processing within page fault handler tracing showed as Peter said 'there's just too much fail surface'. Related list discussions: http://marc.info/?t=139302086500001&r=1&w=2 http://marc.info/?t=139301437300003&r=1&w=2 Suggested-by: Peter Zijlstra Signed-off-by: Jiri Olsa Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: "H. Peter Anvin" Cc: Vince Weaver Cc: Steven Rostedt Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1393775800-13524-2-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar

perf/trace: Properly use u64 to hold event_id

2013-11-19T15:57:44Z

The 64-bit attr.config value for perf trace events was being copied into an "int" before doing a comparison, meaning the top 32 bits were being truncated. As far as I can tell this didn't cause any errors, but it did mean it was possible to create valid aliases for all the tracepoint ids which I don't think was intended. (For example, 0xffffffff00000018 and 0x18 both enable the same tracepoint). Signed-off-by: Vince Weaver Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1311151236100.11932@vincent-weaver-1.um.maine.edu Signed-off-by: Ingo Molnar

ftrace, perf: Avoid infinite event generation loop

2013-11-19T15:57:40Z

Vince's perf-trinity fuzzer found yet another 'interesting' problem. When we sample the irq_work_exit tracepoint with period==1 (or PERF_SAMPLE_PERIOD) and we add an fasync SIGNAL handler we create an infinite event generation loop: ,-> | irq_work_exit() -> | trace_irq_work_exit() -> | ... | __perf_event_overflow() -> (due to fasync) | irq_work_queue() -> (irq_work_list must be empty) '--------- arch_irq_work_raise() Similar things can happen due to regular poll() wakeups if we exceed the ring-buffer wakeup watermark, or have an event_limit. To avoid this, dis-allow sampling this particular tracepoint. In order to achieve this, create a special perf_perm function pointer for each event and call this (when set) on trying to create a tracepoint perf event. [ roasted: use expr... to allow for ',' in your expression ] Reported-by: Vince Weaver Tested-by: Vince Weaver Signed-off-by: Peter Zijlstra Cc: Steven Rostedt Cc: Dave Jones Cc: Frederic Weisbecker Link: http://lkml.kernel.org/r/20131114152304.GC5364@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar

perf/ftrace: Fix paranoid level for enabling function tracer

2013-11-06T19:44:49Z

The current default perf paranoid level is "1" which has "perf_paranoid_kernel()" return false, and giving any operations that use it, access to normal users. Unfortunately, this includes function tracing and normal users should not be allowed to enable function tracing by default. The proper level is defined at "-1" (full perf access), which "perf_paranoid_tracepoint_raw()" will only give access to. Use that check instead for enabling function tracing. Reported-by: Dave Jones Reported-by: Vince Weaver Tested-by: Vince Weaver Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Jiri Olsa Cc: Frederic Weisbecker Cc: stable@vger.kernel.org # 3.4+ CVE: CVE-2013-2930 Fixes: ced39002f5ea ("ftrace, perf: Add support to use function tracepoint in perf") Signed-off-by: Steven Rostedt