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2009-04-29tracing: x86, mmiotrace: only register for die notifier when tracer activeStuart Bennett1-0/+2
Follow up to afcfe024aebd74b0984a41af9a34e009cf5badaf in Linus' tree ("x86: mmiotrace: quieten spurious warning message") Signed-off-by: Stuart Bennett <stuart@freedesktop.org> Acked-by: Pekka Paalanen <pq@iki.fi> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1240946271-7083-5-git-send-email-stuart@freedesktop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, simplify kmmio_fault()Ingo Molnar1-31/+47
Impact: cleanup Remove an #ifdef from kmmio_fault() - we can do this by providing default implementations for is_kmmio_active() and kmmio_handler(). The compiler optimizes it all away in the !CONFIG_MMIOTRACE case. Also, while at it, clean up mmiotrace.h a bit: - standard header guards - standard vertical spaces for structure definitions No code changed (both with mmiotrace on and off in the config): text data bss dec hex filename 2947 12 12 2971 b9b fault.o.before 2947 12 12 2971 b9b fault.o.after Cc: Pekka Paalanen <pq@iki.fi> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14mmiotrace: remove left-over marker cruftPekka Paalanen1-2/+1
Signed-off-by: Pekka Paalanen <pq@iki.fi> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14x86 mmiotrace: implement mmiotrace_printk()Pekka Paalanen1-2/+15
Offer mmiotrace users a function to inject markers from inside the kernel. This depends on the trace_vprintk() patch. Signed-off-by: Pekka Paalanen <pq@iki.fi> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24mmiotrace: rename kmmio_probe::user_data to :private.Pekka Paalanen1-1/+1
Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24x86 mmiotrace: use resource_size_t for phys addressesPekka Paalanen1-7/+7
Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24mmiotrace: code style cleanupsPekka Paalanen1-5/+1
From c2da03771e29159627c5c7b9509ec70bce9f91ee Mon Sep 17 00:00:00 2001 From: Pekka Paalanen <pq@iki.fi> Date: Mon, 28 Apr 2008 21:25:22 +0300 Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-24ftrace: mmiotrace update, #2Pekka Paalanen1-2/+0
another weekend, another patch. This should apply on top of my previous patch from March 23rd. Summary of changes: - Print PCI device list in output header - work around recursive probe hits on SMP - refactor dis/arm_kmmio_fault_page() and add check for page levels - remove un/reference_kmmio(), the die notifier hook is registered permanently into the list - explicitly check for single stepping in die notifier callback I have tested this version on my UP Athlon64 desktop with Nouveau, and SMP Core 2 Duo laptop with the proprietary nvidia driver. Both systems are 64-bit. One previously unknown bug crept into daylight: the ftrace framework's output routines print the first entry last after buffer has wrapped around. The most important regressions compared to non-ftrace mmiotrace at this time are: - failure of trace_pipe file - illegal lines in output file - unaware of losing data due to buffer full Personally I'd like to see these three solved before submitting to mainline. Other issues may come up once we know when we lose events. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24ftrace: mmiotrace, updatesPekka Paalanen1-60/+25
here is a patch that makes mmiotrace work almost well within the tracing framework. The patch applies on top of my previous patch. I have my own output formatting in place now. Summary of changes: - fix the NULL dereference that was due to not calling tracing_reset() - add print_line() callback into struct tracer - implement print_line() for mmiotrace, producing up-to-spec text - add my output header, but that is not really called in the right place - rewrote the main structs in mmiotrace - added two new trace entry types: TRACE_MMIO_RW and TRACE_MMIO_MAP - made some functions in trace.c non-static - check current==NULL in tracing_generic_entry_update() - fix(?) comparison in trace_seq_printf() Things seem to work fine except a few issues. Markers (text lines injected into mmiotrace log) are missing, I did not feel hacking them in before we have variable length entries. My output header is printed only for 'trace' file, but not 'trace_pipe'. For some reason, despite my quick fix, iter->trace is NULL in print_trace_line() when called from 'trace_pipe' file, which means I don't get proper output formatting. I only tried by loading nouveau.ko, which just detects the card, and that is traced fine. I didn't try further. Map, two reads and unmap. Works perfectly. I am missing the information about overflows, I'd prefer to have a counter for lost events. I didn't try, but I guess currently there is no way of knowning when it overflows? So, not too far from being fully operational, it seems :-) And looking at the diffstat, there also is some 700-900 lines of user space code that just became obsolete. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24ftrace: add mmiotrace pluginPekka Paalanen1-0/+6
On Sat, 22 Mar 2008 13:07:47 +0100 Ingo Molnar <mingo@elte.hu> wrote: > > > i'd suggest the following: pull x86.git and sched-devel.git into a > > > single tree [the two will combine without rejects]. Then try to add a > > > kernel/tracing/trace_mmiotrace.c ftrace plugin. The trace_sysprof.c > > > plugin might be a good example. > > > > I did this and now I have mmiotrace enabled/disabled via the tracing > > framework (what do we call this, since ftrace is one of the tracers?). > > cool! could you send the patches for that? (even if they are not fully > functional yet) Patch attached in the end. Nice to see how much code disappeared. I tried to mark all the features I had to break with XXX-comments. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24x86: mmiotrace, preview 2Pekka Paalanen1-1/+17
Kconfig.debug, Makefile and testmmiotrace.c style fixes. Use real mutex instead of mutex. Fix failure path in register probe func. kmmio: RCU read-locked over single stepping. Generate mapping id's. Make mmio-mod.c built-in and rewrite its locking. Add debugfs file to enable/disable mmiotracing. kmmio: use irqsave spinlocks. Lots of cleanups in mmio-mod.c Marker file moved from /proc into debugfs. Call mmiotrace entrypoints directly from ioremap.c. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24x86: mmiotrace full patch, preview 1Pekka Paalanen1-0/+38
kmmio.c handles the list of mmio probes with callbacks, list of traced pages, and attaching into the page fault handler and die notifier. It arms, traps and disarms the given pages, this is the core of mmiotrace. mmio-mod.c is a user interface, hooking into ioremap functions and registering the mmio probes. It also decodes the required information from trapped mmio accesses via the pre and post callbacks in each probe. Currently, hooking into ioremap functions works by redefining the symbols of the target (binary) kernel module, so that it calls the traced versions of the functions. The most notable changes done since the last discussion are: - kmmio.c is a built-in, not part of the module - direct call from fault.c to kmmio.c, removing all dynamic hooks - prepare for unregistering probes at any time - make kmmio re-initializable and accessible to more than one user - rewrite kmmio locking to remove all spinlocks from page fault path Can I abuse call_rcu() like I do in kmmio.c:unregister_kmmio_probe() or is there a better way? The function called via call_rcu() itself calls call_rcu() again, will this work or break? There I need a second grace period for RCU after the first grace period for page faults. Mmiotrace itself (mmio-mod.c) is still a module, I am going to attack that next. At some point I will start looking into how to make mmiotrace a tracer component of ftrace (thanks for the hint, Ingo). Ftrace should make the user space part of mmiotracing as simple as 'cat /debug/trace/mmio > dump.txt'. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24x86 mmiotrace: comment about user space ABIPekka Paalanen1-1/+5
Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24x86: mmiotrace - trace memory mapped IOPekka Paalanen1-0/+62
Mmiotrace is a tool for trapping memory mapped IO (MMIO) accesses within the kernel. It is used for debugging and especially for reverse engineering evil binary drivers. Mmiotrace works by wrapping the ioremap family of kernel functions and marking the returned pages as not present. Access to the IO memory triggers a page fault, which will be handled by mmiotrace's custom page fault handler. This will single-step the faulted instruction with the MMIO page marked as present. Access logs are directed to user space via relay and debug_fs. This page fault approach is necessary, because binary drivers have readl/writel etc. calls inlined and therefore extremely difficult to trap with with e.g. kprobes. This patch depends on the custom page fault handlers patch. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>