- 21 Aug, 2012 1 commit
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Ingo Molnar authored
Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core Pull ftrace updates from Steve Rostedt: " This patch series extends ftrace function tracing utility to be more dynamic for its users. It allows for data passing to the callback functions, as well as reading regs as if a breakpoint were to trigger at function entry. The main goal of this patch series was to allow kprobes to use ftrace as an optimized probe point when a probe is placed on an ftrace nop. With lots of help from Masami Hiramatsu, and going through lots of iterations, we finally came up with a good solution. " Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 31 Jul, 2012 13 commits
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Masami Hiramatsu authored
Add function tracer based kprobe optimization support handlers on x86. This allows kprobes to use function tracer for probing on mcount call. Link: http://lkml.kernel.org/r/20120605102838.27845.26317.stgit@localhost.localdomain Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [ Updated to new port of ftrace save regs functions ] Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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Masami Hiramatsu authored
Introduce function trace based kprobes optimization. With using ftrace optimization, kprobes on the mcount calling address, use ftrace's mcount call instead of breakpoint. Furthermore, this optimization works with preemptive kernel not like as current jump-based optimization. Of cource, this feature works only if the probe is on mcount call. Only if kprobe.break_handler is set, that probe is not optimized with ftrace (nor put on ftrace). The reason why this limitation comes is that this break_handler may be used only from jprobes which changes ip address (for fetching the function arguments), but function tracer ignores modified ip address. Changes in v2: - Fix ftrace_ops registering right after setting its filter. - Unregister ftrace_ops if there is no kprobe using. - Remove notrace dependency from __kprobes macro. Link: http://lkml.kernel.org/r/20120605102832.27845.63461.stgit@localhost.localdomain Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
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Steven Rostedt authored
When CONFIG_DYNAMIC_FTRACE is not set, ftrace_location() is not defined. If a user (like kprobes) references this function, it will break the compile when CONFIG_DYNAMIC_FTRACE is not set. Add ftrace_location() as a nop (return 0) when DYNAMIC_FTRACE is not defined. Link: http://lkml.kernel.org/r/20120612225426.961092717@goodmis.orgSigned-off-by:
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Masami Hiramatsu authored
Break a big critical region into fine-grained pieces at registering kprobe path. This helps us to solve circular locking dependency when introducing ftrace-based kprobes. Link: http://lkml.kernel.org/r/20120605102826.27845.81689.stgit@localhost.localdomain Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
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Masami Hiramatsu authored
Separate probe-able address checking code from register_kprobe(). Link: http://lkml.kernel.org/r/20120605102820.27845.90133.stgit@localhost.localdomain Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
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Steven Rostedt authored
Currently module_mutex is taken before kprobe_mutex, but this can cause issues when we have kprobes register ftrace, as the ftrace mutex is taken before enabling a tracepoint, which currently takes the module mutex. If module_mutex is taken before kprobe_mutex, then we can not have kprobes use the ftrace infrastructure. There seems to be no reason that the kprobe_mutex can't be taken before the module_mutex. Running lockdep shows that it is safe among the kernels I've run. Link: http://lkml.kernel.org/r/20120605102814.27845.21047.stgit@localhost.localdomain Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by:
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Masami Hiramatsu authored
Add a new filter update interface ftrace_set_filter_ip() to set ftrace filter by ip address, not only glob pattern. Link: http://lkml.kernel.org/r/20120605102808.27845.67952.stgit@localhost.localdomain Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
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Steven Rostedt authored
Add selftests to test the save-regs functionality of ftrace. If the arch supports saving regs, then it will make sure that regs is at least not NULL in the callback. If the arch does not support saving regs, it makes sure that the registering of the ftrace_ops that requests saving regs fails. It then tests the registering of the ftrace_ops succeeds if the 'IF_SUPPORTED' flag is set. Then it makes sure that the regs passed to the function is NULL. Signed-off-by: -
Steven Rostedt authored
Add selftests to test the function tracing recursion protection actually does work. It also tests if a ftrace_ops states it will perform its own protection. Although, even if the ftrace_ops states it will protect itself, the ftrace infrastructure may still provide protection if the arch does not support all features or another ftrace_ops is registered. Signed-off-by: -
Steven Rostedt authored
No need to compile in the ftrace selftest helper file if selftests are not being executed. Signed-off-by: -
Steven Rostedt authored
As more users of the function tracer utility are being added, they do not always add the necessary recursion protection. To protect from function recursion due to tracing, if the callback ftrace_ops does not specifically specify that it protects against recursion (by setting the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be called by the mcount trampoline which adds recursion protection. If the flag is set, then the function will be called directly with no extra protection. Note, the list operation is called if more than one function callback is registered, or if the arch does not support all of the function tracer features. Signed-off-by: -
Steven Rostedt authored
The graph caller is called by the mcount callers, which already does the check against the function_trace_stop variable. No reason to check it again. Link: http://lkml.kernel.org/r/20120711195745.588538769@goodmis.orgSigned-off-by:
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Uros Bizjak authored
The final position of the stack after saving regs and setting up the parameters for ftrace_regs_call, is the position of the pt_regs needed for the 4th parameter. Instead of saving it into a temporary reg and pushing the reg, simply push the stack pointer. Link: http://lkml.kernel.org/r/1342702344.12353.16.camel@gandalf.stny.rr.comReviewed-by:
Uros Bizjak <ubizjak@gmail.com> Signed-off-by:
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- 30 Jul, 2012 14 commits
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Oleg Nesterov authored
Like do_wp_page(), __replace_page() should do munlock_vma_page() for the case when the old page still has other !VM_LOCKED mappings. Unfortunately this needs mm/internal.h. Also, move put_page() outside of ptl lock. This doesn't really matter but looks a bit better. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182249.GA20372@redhat.comSigned-off-by:
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Oleg Nesterov authored
1. vma_address() returns loff_t, this looks confusing and this is unnecessary after the previous change. Make it return "ulong", all callers truncate the result anyway. 2. Its name conflicts with mm/rmap.c:vma_address(), rename it to offset_to_vaddr(), this matches vaddr_to_offset(). Signed-off-by:
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Oleg Nesterov authored
1. register_for_each_vma() checks that vma_address() == vaddr, but this is not enough. We should also ensure that vaddr >= vm_start, find_vma() guarantees "vaddr < vm_end" only. 2. After the prevous changes, register_for_each_vma() is the only reason why vma_address() has to return loff_t, all other users know that we have the valid mapping at this offset and thus the overflow is not possible. Change the code to use vaddr_to_offset() instead, imho this looks more clean/understandable and now we can change vma_address(). 3. While at it, remove the unnecessary type-cast. Signed-off-by:
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Oleg Nesterov authored
Add the new helper, vaddr_to_offset(vma, vaddr) which returns the offset in vma->vm_file this vaddr is mapped at. Change build_probe_list() and find_active_uprobe() to use the new helper, the next patch adds another user. Signed-off-by:
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Oleg Nesterov authored
Currently build_probe_list() builds the list of all uprobes attached to the given inode, and the caller should filter out those who don't fall into the [start,end) range, this is sub-optimal. This patch turns find_least_offset_node() into find_node_in_range() which returns the first node inside the [min,max] range, and changes build_probe_list() to use this node as a starting point for rb_prev() and rb_next() to find all other nodes the caller needs. The resulting list is no longer sorted but we do not care. This can speed up both build_probe_list() and the callers, but there is another reason to introduce find_node_in_range(). It can be used to figure out whether the given vma has uprobes or not, this will be needed soon. While at it, shift INIT_LIST_HEAD(tmp_list) into build_probe_list(). Signed-off-by:
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Oleg Nesterov authored
Remove insert_vm_struct()->uprobe_mmap(). It is not needed, nobody except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with vma->vm_file != NULL. And it is wrong. Again, get_user_pages() can not succeed before vma_link(vma) makes is visible to find_vma(). And even if this worked, we must not insert the new bp before this mapping is visible to vma_prio_tree_foreach() for uprobe_unregister(). Signed-off-by:
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Oleg Nesterov authored
Remove copy_vma()->uprobe_mmap(new_vma), it is absolutely wrong. This new_vma was just initialized to represent the new unmapped area, [vm_start, vm_end) was returned by get_unmapped_area() in the caller. This means that uprobe_mmap()->get_user_pages() will fail for sure, simply because find_vma() can never succeed. And I verified that sys_mremap()->mremap_to() indeed always fails with the wrong ENOMEM code if [addr, addr+old_len] is probed. And why this uprobe_mmap() was added? I believe the intent was wrong. Note that the caller is going to do move_page_tables(), all registered uprobes are already faulted in, we only change the virtual addresses. NOTE: However, somehow we need to close the race with uprobe_register() which relies on map_info->vaddr. This needs another fix I'll try to do later. Probably we need uprobe_mmap() in move_vma() but we can not do this right now, this can confuse uprobes_state.counter (which I still hope we are going to kill). Signed-off-by:
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Oleg Nesterov authored
vma->vm_pgoff is "unsigned long", it should be promoted to loff_t before the multiplication to avoid the overflow. Signed-off-by:
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Oleg Nesterov authored
uprobe_munmap() does get_user_pages() and it is also called from the final mmput()->exit_mmap() path. This slows down exit/mmput() for no reason, and I think it is simply dangerous/wrong to try to fault-in a page into the dying mm. If nothing else, this happens after the last sync_mm_rss(), afaics handle_mm_fault() can change the task->rss_stat and make the subsequent check_mm() unhappy. Change uprobe_munmap() to check mm->mm_users != 0. Signed-off-by:
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Oleg Nesterov authored
The bug was introduced by me in 449d0d7c ("uprobes: Simplify the usage of uprobe->pending_list"). Yes, we do not care about uprobe->pending_list after return and nobody can remove the current list entry, but put_uprobe(uprobe) can actually free it and thus we need list_for_each_safe(). Reported-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by:
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Oleg Nesterov authored
The comment above write_opcode()->lock_page(old_page) tells about the race with do_wp_page(). I don't really understand which exactly race it means, but afaics this lock_page() was not enough to close all races with do_wp_page(). Anyway, since: 77fc4af1 uprobes: Change register_for_each_vma() to take mm->mmap_sem for writing this code is always called with ->mmap_sem held for writing, so we can forget about do_wp_page(). However, we can't simply remove this lock_page(), and the only (afaics) reason is __replace_page()->try_to_free_swap(). Nothing in write_opcode() needs it, move it into __replace_page() and fix the comment. Signed-off-by:
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Oleg Nesterov authored
write_opcode() does lock_page(new_page) for no reason. Nobody can see this page until __replace_page() exposes it under ptl lock, and we do nothing with this page after pte_unmap_unlock(). If nothing else, the similar code in do_wp_page() doesn't lock the new page for page_add_new_anon_rmap/set_pte_at_notify. Signed-off-by:
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Oleg Nesterov authored
page_address_in_vma(old_page) in __replace_page() is ugly and wrong. The caller already knows the correct virtual address, this page was found by get_user_pages(vaddr). However, page_address_in_vma() can actually fail if page->mapping was cleared by __delete_from_page_cache() after get_user_pages() returns. But this means the race with page reclaim, write_opcode() should not fail, it should retry and read this page again. Probably the race with remove_mapping() is not possible due to page_freeze_refs() logic, but afaics at least shmem_writepage()->shmem_delete_from_page_cache() can clear ->mapping. We could change __replace_page() to return -EAGAIN in this case, but it would be better to simply use the caller's vaddr and rely on page_check_address(). Signed-off-by:
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Oleg Nesterov authored
write_opcode() rechecks valid_vma() and ->f_mapping, this is pointless. The caller, register_for_each_vma() or uprobe_mmap(), has already done these checks under mmap_sem. To clarify, uprobe_mmap() checks valid_vma() only, but we can rely on build_probe_list(vm_file->f_mapping->host). Signed-off-by:
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- 26 Jul, 2012 7 commits
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Jovi Zhang authored
When CONFIG_PERF_EVENTS disabled, there will have a compiliation error, because missing struct before structure name. Signed-off-by:
Jovi Zhang <bookjovi@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jiri Kosina <trivial@kernel.org> Link: http://lkml.kernel.org/r/CACV3sbKF%3DCX%2B2jWEWesfCA6rBoQ3wDM4-5ac9MuBtVbCtMRHdQ@mail.gmail.comSigned-off-by:
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Yan, Zheng authored
The event control register of SNB-EP uncore QPI box has a one bit extension at bit position 21. Reported-by:
Stephane Eranian <eranian@google.com> Signed-off-by:
Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1343097850-4348-1-git-send-email-zheng.z.yan@intel.comSigned-off-by:
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Peter Zijlstra authored
Fix: arch/x86/kernel/cpu/perf_event.h:377:43: sparse: dubious one-bit signed bitfield Cc: Borislav Petkov <bp@amd64.org> Reported-by:
Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
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Yan, Zheng authored
LLC-* and node-* events require using the OFFCORE_RESPONSE events on SandyBridge, but the hw_cache_extra_regs is left uninitialized. This patch adds the missing extra register configure table for SandyBridge. Signed-off-by:
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Yan, Zheng authored
The uncore subsystem in Nehalem-EX consists of 7 components (U-Box, C-Box, B-Box, S-Box, R-Box, M-Box and W-Box). This patch is large because the way to program these boxes is diverse. Signed-off-by:
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Yan, Zheng authored
The format definition of uncore PCU filter should be filter_band* instead of filter_brand*. Reported-by:
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Andrew Vagin authored
Otherwise they can't be filtered for a defined task: perf record -e sched:sched_switch ./foo This command doesn't report any events without this patch. I think it isn't a security concern if someone knows who will be executed next - this can already be observed by polling /proc state. By default perf is disabled for non-root users in any case. I need these events for profiling sleep times. sched_switch is used for getting callchains and sched_stat_* is used for getting time periods. These events are combined in user space, then it can be analyzed by perf tools. Signed-off-by:
Andrew Vagin <avagin@openvz.org> Signed-off-by:
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- 25 Jul, 2012 5 commits
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Ingo Molnar authored
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core fixes and improvements from Arnaldo Carvalho de Melo: * libtraceevent build fixes from Namhyung Kim * Prevent overflow when calculating annotation buckets size, from Cody Schafer * Set breakpoint events sample period to 1, just like trace events, from Jovi Zhang * Fix strerror_r usage, from Kirill Shutemov * Fix duplicate function declaration problems with bison 2.6, from Kirill Shutemov * Add DSO caching facility (and perf test entry) to speed up binary file reading, will be used by the DWARF unwind code, from Jiri Olsa * Fix trace event storms by setting PERF_SAMPLE_PERIOD, from Frederic Weisbecker * perf kvm fixes from David Ahern Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
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Cody Schafer authored
A large enough symbol size causes an overflow in the size parameter to the histogram allocation, leading to a segfault in symbol__inc_addr_samples later on when this histogram is accessed. In the case of being called via perf-report, this returns back and gracefully ignores the sample, eventually ignoring the chained return value of perf_session_deliver_event in flush_sample_queue. Signed-off-by:
Cody Schafer <cody@linux.vnet.ibm.com> Acked-by:
Namhyung Kim <namhyung@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1342753525-4521-1-git-send-email-cody@linux.vnet.ibm.comSigned-off-by:
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Namhyung Kim authored
The TRACEEVENT-CFLAGS file is used to detect any change on compiler flags. Just ignore it. Signed-off-by:
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Namhyung Kim authored
Cross compiling perf requires setting ARCH and CROSS_COMPILE variables, but libtraceevent couldn't detect the changes so it ends up believing no recompiling is required. Thus the linker failed like: LINK perf ../lib/traceevent//libtraceevent.a: member ../lib/traceevent//libtraceevent.a(event-parse.o) in archive is not an object collect2: ld returned 1 exit status make: *** [perf] Error 1 This patch fixes this by adding TRACEEVENT-CFLAGS file like PERF-CFLAGS to track those changes. Signed-off-by: -
Kirill A. Shutemov authored
Bison 2.6 started to generate parse_events_parse() declaration in header. In this case we have redundant redeclaration: util/parse-events.c:29:5: error: redundant redeclaration of ‘parse_events_parse’ [-Werror=redundant-decls] In file included from util/parse-events.c:14:0: util/parse-events-bison.h:99:5: note: previous declaration of ‘parse_events_parse’ was here cc1: all warnings being treated as errors Let's disable -Wredundant-decls for util/parse-events.c since it includes header we can't control. Signed-off-by:
Kirill A. Shutemov <kirill@shutemov.name> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120723210407.GA25186@shutemov.nameSigned-off-by:
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