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2012-06-18Merge branch 'tip/perf/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core Pull ftrace robustization fixes from Steve Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-17irqdomain: Make ops->map hook optionalGrant Likely
There isn't a really compelling reason to force ->map to be populated, so allow it to be left unset. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <rob.herring@calxeda.com>
2012-06-16printk: return -EINVAL if the message len is bigger than the buf sizeYuanhan Liu
Just like what devkmsg_read() does, return -EINVAL if the message len is bigger than the buf size, or it will trigger a segfault error. Acked-by: Kay Sievers <kay@vrfy.org> Acked-by: Fengguang Wu <wfg@linux.intel.com> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-16printk: use mutex lock to stop syslog_seq from going wildYuanhan Liu
Although syslog_seq and log_next_seq stuff are protected by logbuf_lock spin log, it's not enough. Say we have two processes A and B, and let syslog_seq = N, while log_next_seq = N + 1, and the two processes both come to syslog_print at almost the same time. And No matter which process get the spin lock first, it will increase syslog_seq by one, then release spin lock; thus later, another process increase syslog_seq by one again. In this case, syslog_seq is bigger than syslog_next_seq. And latter, it would make: wait_event_interruptiable(log_wait, syslog != log_next_seq) don't wait any more even there is no new write comes. Thus it introduce a infinite loop reading. I can easily see this kind of issue by the following steps: # cat /proc/kmsg # at meantime, I don't kill rsyslog # So they are the two processes. # xinit # I added drm.debug=6 in the kernel parameter line, # so that it will produce lots of message and let that # issue happen It's 100% reproducable on my side. And my disk will be filled up by /var/log/messages in a quite short time. So, introduce a mutex_lock to stop syslog_seq from going wild just like what devkmsg_read() does. It does fix this issue as expected. v2: use mutex_lock_interruptiable() instead (comments from Kay) Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Acked-By: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-16uprobes: Remove the unnecessary initialization in add_utask()Oleg Nesterov
Trivial cleanup. No need to nullify ->active_uprobe after kzalloc(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120615154401.GA9633@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: __copy_insn() needs "loff_t offset"Oleg Nesterov
1. __copy_insn() needs "loff_t offset", not "unsigned long", to read the file. 2. use pgoff_t for "idx" and remove the unnecessary typecast. 3. fix the typo, "&=" is not what we want 4. can't resist, rename off1 to off. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154359.GA9625@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Don't use loff_t for the valid virtual addressOleg Nesterov
loff_t looks confusing when it is used for the virtual address. Change map_info and install_breakpoint/remove_breakpoint paths to use "unsigned long". The patch doesn't change vma_address(), it can't return "long" because it is used to verify the mapping. But probably this needs some cleanups too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154355.GA9622@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Simplify the usage of uprobe->pending_listOleg Nesterov
uprobe->pending_list is only used to create the temporary list, it has no meaning after we drop uprobes_mmap_hash(inode). No need to initialize this node or remove it from tmp_list, and we can use list_for_each_entry(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120615154353.GA9614@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Move BUG_ON(UPROBE_SWBP_INSN_SIZE) from write_opcode() to ↵Oleg Nesterov
install_breakpoint() write_opcode() ensures that UPROBE_SWBP_INSN doesn't cross the page boundary. This looks a bit confusing, the check does not depend on vaddr and it is enough to do it only once right after install_breakpoint()->arch_uprobe_analyze_insn(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154350.GA9611@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: No need to re-check vma_address() in write_opcode()Oleg Nesterov
write_opcode() is called by register_for_each_vma() and uprobe_mmap() paths. In both cases the caller has already verified this vaddr under mmap_sem, no need to re-check. Note also that this check is wrong anyway, we should not truncate loff_t returned by vma_address() if we do not trust this mapping. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154347.GA9604@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Copy_insn() should not return -ENOMEM if __copy_insn() failsOleg Nesterov
copy_insn() returns -ENOMEM if the first __copy_insn() fails, it should return the correct error code. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154344.GA9601@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Copy_insn() shouldn't depend on mm/vma/vaddrOleg Nesterov
1. copy_insn() doesn't need "addr", it can use uprobe->offset. Remove this argument. 2. Change copy_insn/__copy_insn to accept "struct file*" instead of vma. copy_insn() is called only once and mm/vma/vaddr are random, it shouldn't depend on them. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154342.GA9598@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Document uprobe_register() vs uprobe_mmap() racePeter Zijlstra
Because the mind is treacherous and makes us forget we need to write stuff down. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120615154339.GA9591@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Change build_map_info() to try kmalloc(GFP_NOWAIT) firstOleg Nesterov
build_map_info() doesn't allocate the memory under i_mmap_mutex to avoid the deadlock with page reclaim. But it can try GFP_NOWAIT first, it should work in the likely case and thus we almost never need the pre-alloc-and-retry path. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Link: http://lkml.kernel.org/r/20120615154336.GA9588@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Rework register_for_each_vma() to make it O(n)Oleg Nesterov
Currently register_for_each_vma() is O(n ** 2) + O(n ** 3), every time find_next_vma_info() "restarts" the vma_prio_tree_foreach() loop and each iteration rechecks the whole try_list. This also means that try_list can grow "indefinitely" if register/unregister races with munmap/mmap activity even if the number of mapping is bounded at any time. With this patch register_for_each_vma() builds the list of mm/vaddr structures only once and does install_breakpoint() for each entry. We do not care about the new mappings which can be created after build_map_info() drops mapping->i_mmap_mutex, uprobe_mmap() should do its work. Note that we do not allocate map_info under i_mmap_mutex, this can deadlock with page reclaim (but see the next patch). So we use 2 lists, "curr" which we are going to return, and "prev" which holds the already allocated memory. The main loop deques the entry from "prev" (initially it is empty), and if "prev" becomes empty again it counts the number of entries we need to pre-allocate outside of i_mmap_mutex. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Link: http://lkml.kernel.org/r/20120615154333.GA9581@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Install_breakpoint() should fail if is_swbp_insn() == TOleg Nesterov
install_breakpoint() returns -EEXIST if is_swbp_insn(orig_insn) == T, the caller treats this code as success. This is doubly wrong. The successful return should set UPROBE_COPY_INSN, but the real problem is that it shouldn't succeed. If the probed insn is int3 the application should get SIGTRAP, this won't happen with uprobe. Probably we can fix this, we can add the UPROBE_SHARED_BP flag and teach handle_swbp/set_orig_insn to handle this case correctly. But this needs some complications and we have other insns which can't be probed, lets make a simple fix for now. I think this needs a cleanup. UPROBE_COPY_INSN should die, copy_insn() should be called by alloc_uprobe(). arch_uprobe_analyze_insn() depends on ->mm (ia32_compat) but it is called only once. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154331.GA9578@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Write_opcode()->__replace_page() can race with try_to_unmap()Oleg Nesterov
write_opcode() gets old_page via get_user_pages() and then calls __replace_page() which assumes that this old_page is still mapped after pte_offset_map_lock(). This is not true if this old_page was already try_to_unmap()'ed, and in this case everything __replace_page() does with old_page is wrong. Just for example, put_page() is not balanced. I think it is possible to teach __replace_page() to handle this unlikely case correctly, but this patch simply changes it to use page_check_address() and return -EAGAIN if it fails. The caller should notice this error code and retry. Note: write_opcode() asks for the cleanups, I'll try to do this in a separate patch. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154328.GA9571@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: __copy_insn() should ensure a_ops->readpage != NULLOleg Nesterov
__copy_insn() blindly calls read_mapping_page(), this will crash the kernel if ->readpage == NULL, add the necessary check. For example, hugetlbfs_aops->readpage is NULL. Perhaps we should change read_mapping_page() instead. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154325.GA9568@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16uprobes: Valid_vma() should reject VM_HUGETLBOleg Nesterov
__replace_page() obviously can't work with the hugetlbfs mappings, uprobe_register() will likely crash the kernel. Change valid_vma() to check VM_HUGETLB as well. As for PageTransHuge() no need to worry, vma->vm_file != NULL. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154322.GA9561@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-15Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: watchdog: Quiet down the boot messages perf/x86: Fix broken LBR fixup code tracing: Have tracing_off() actually turn tracing off
2012-06-15Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core updates (RCU and locking) from Ingo Molnar: "Most of the diffstat comes from the RCU slow boot regression fixes, but there's also a debuggability improvements/fixes." * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: memblock: Document memblock_is_region_{memory,reserved}() rcu: Precompute RCU_FAST_NO_HZ timer offsets rcu: Move RCU_FAST_NO_HZ per-CPU variables to rcu_dynticks structure rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks rcu: RCU_FAST_NO_HZ detection of callback adoption spinlock: Indicate that a lockup is only suspected kdump: Execute kmsg_dump(KMSG_DUMP_PANIC) after smp_send_stop() panic: Make panic_on_oops configurable
2012-06-15kmsg - kmsg_dump() use iterator to receive log buffer contentKay Sievers
Provide an iterator to receive the log buffer content, and convert all kmsg_dump() users to it. The structured data in the kmsg buffer now contains binary data, which should no longer be copied verbatim to the kmsg_dump() users. The iterator should provide reliable access to the buffer data, and also supports proper log line-aware chunking of data while iterating. Signed-off-by: Kay Sievers <kay@vrfy.org> Tested-by: Tony Luck <tony.luck@intel.com> Reported-by: Anton Vorontsov <anton.vorontsov@linaro.org> Tested-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-15irqdomain: Remove unnecessary test for IRQ_DOMAIN_MAP_LEGACYGrant Likely
Where irq_domain_associate() is called in irq_create_mapping, there is no need to test for IRQ_DOMAIN_MAP_LEGACY because it is already tested for earlier in the routine. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <rob.herring@calxeda.com>
2012-06-15irqdomain: Simple NUMA awareness.Paul Mundt
While common irqdesc allocation is node aware, the irqdomain code is not. Presently we observe a number of regressions/inconsistencies on NUMA-capable platforms: - Platforms using irqdomains with legacy mappings, where the irq_descs are allocated node-local and the irqdomain data structure is not. - Drivers implementing irqdomains will lose node locality regardless of the underlying struct device's node id. This plugs in NUMA node id proliferation across the various allocation callsites by way of_node_to_nid() node lookup. While of_node_to_nid() does the right thing for OF-capable platforms it doesn't presently handle the non-DT case. This is trivially dealt with by simply wraping in to numa_node_id() unconditionally. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-06-15devicetree: add helper inline for retrieving a node's full nameGrant Likely
The pattern (np ? np->full_name : "<none>") is rather common in the kernel, but can also make for quite long lines. This patch adds a new inline function, of_node_full_name() so that the test for a valid node pointer doesn't need to be open coded at all call sites. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-14tracing: Register the ftrace internal events during early bootSteven Rostedt
All trace events including ftrace internel events (like trace_printk and function tracing), register functions that describe how to print their output. The events may be recorded as soon as the ring buffer is allocated, but they are just raw binary in the buffer. The mapping of event ids to how to print them are held within a structure that is registered on system boot. If a crash happens in boot up before these functions are registered then their output (via ftrace_dump_on_oops) will be useless: Dumping ftrace buffer: --------------------------------- <...>-1 0.... 319705us : Unknown type 6 --------------------------------- This can be quite frustrating for a kernel developer trying to see what is going wrong. There's no reason to register them so late in the boot up process. They can be registered by early_initcall(). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-06-14ftrace: Remove a superfluous checkBorislav Petkov
register_ftrace_function() checks ftrace_disabled and calls __register_ftrace_function which does it again. Drop the first check and add the unlikely hint to the second one. Also, drop the label as John correctly notices. No functional change. Link: http://lkml.kernel.org/r/20120329171140.GE6409@aftab Cc: Borislav Petkov <bp@amd64.org> Cc: John Kacur <jkacur@redhat.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-06-14watchdog: Quiet down the boot messagesDon Zickus
A bunch of bugzillas have complained how noisy the nmi_watchdog is during boot-up especially with its expected failure cases (like virt and bios resource contention). This is my attempt to quiet them down and keep it less confusing for the end user. What I did is print the message for cpu0 and save it for future comparisons. If future cpus have an identical message as cpu0, then don't print the redundant info. However, if a future cpu has a different message, happily print that loudly. Before the change, you would see something like: ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 CPU0: Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping 0a Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver. ... version: 2 ... bit width: 40 ... generic registers: 2 ... value mask: 000000ffffffffff ... max period: 000000007fffffff ... fixed-purpose events: 3 ... event mask: 0000000700000003 NMI watchdog enabled, takes one hw-pmu counter. Booting Node 0, Processors #1 NMI watchdog enabled, takes one hw-pmu counter. #2 NMI watchdog enabled, takes one hw-pmu counter. #3 Ok. NMI watchdog enabled, takes one hw-pmu counter. Brought up 4 CPUs Total of 4 processors activated (22607.24 BogoMIPS). After the change, it is simplified to: ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 CPU0: Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping 0a Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver. ... version: 2 ... bit width: 40 ... generic registers: 2 ... value mask: 000000ffffffffff ... max period: 000000007fffffff ... fixed-purpose events: 3 ... event mask: 0000000700000003 NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter. Booting Node 0, Processors #1 #2 #3 Ok. Brought up 4 CPUs V2: little changes based on Joe Perches' feedback V3: printk cleanup based on Ingo's feedback; checkpatch fix V4: keep printk as one long line V5: Ingo fix ups Reported-and-tested-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: nzimmer@sgi.com Cc: joe@perches.com Link: http://lkml.kernel.org/r/1339594548-17227-1-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-13resources: allow adjust_resource() for resources with no parentYinghai Lu
If a resource has no parent, allow its start/end to be set arbitrarily as long as any children are still contained within the new range. [bhelgaas: changelog] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13splice: fix racy pipe->buffers usesEric Dumazet
Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered by splice_shrink_spd() called from vmsplice_to_pipe() commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes) added capability to adjust pipe->buffers. Problem is some paths don't hold pipe mutex and assume pipe->buffers doesn't change for their duration. Fix this by adding nr_pages_max field in struct splice_pipe_desc, and use it in place of pipe->buffers where appropriate. splice_shrink_spd() loses its struct pipe_inode_info argument. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Tom Herbert <therbert@google.com> Cc: stable <stable@vger.kernel.org> # 2.6.35 Tested-by: Dave Jones <davej@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-12printk: Fix alignment of buf causing crash on ARM EABIAndrew Lunn
Commit 7ff9554bb578ba02166071d2d487b7fc7d860d62, printk: convert byte-buffer to variable-length record buffer, causes systems using EABI to crash very early in the boot cycle. The first entry in struct log is a u64, which for EABI must be 8 byte aligned. Make use of __alignof__() so the compiler to decide the alignment, but allow it to be overridden using CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, for systems which can perform unaligned access and want to save a few bytes of space. Tested on Orion5x and Kirkwood. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-11Merge branch 'nohz-for-tip-2' of git://github.com/fweisbec/linux-dynticks ↵Thomas Gleixner
into timers/core
2012-06-11nohz: Move next idle expiry time record into idle logic areaFrederic Weisbecker
The next idle expiry time record and idle sleeps tracking are statistics that only concern idle. Since we want the nohz APIs to become usable further idle context, let's pull up the handling of these statistics to the callers in idle. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-11nohz: Move ts->idle_calls incrementation into strict idle logicFrederic Weisbecker
Since we want to prepare for making the nohz API to work further the idle case, we need to pull ts->idle_calls incrementation up to the callers in idle. To perform this, we split tick_nohz_stop_sched_tick() in two parts: a first one that checks if we can really stop the tick for idle, and another that actually stops it. Then from the callers in idle, we check if we can stop the tick and only then we increment idle_calls and finally relay to the nohz API that won't care about these details anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-11nohz: Rename ts->idle_tick to ts->last_tickFrederic Weisbecker
Now that idle and nohz logics are going to be independant each others, ts->idle_tick becomes too much a biased name to describe the field that saves the last scheduled tick on top of which we re-calculate the next tick to schedule when the timer is restarted. We want to reuse this even to stop the tick outside idle cases. So let's rename it to some more generic name: ts->last_tick. This changes a bit the timer list stat export so we need to increase its version. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-11nohz: Make nohz API agnostic against idle ticks cputime accountingFrederic Weisbecker
When the timer tick fires, it accounts the new jiffy as either part of system, user or idle time. This is how we record the cputime statistics. But when the tick is stopped from the idle task, we still need to record the number of jiffies spent tickless until we restart the tick and fall back to traditional tick-based cputime accounting. To do this, we take a snapshot of jiffies when the tick is stopped and compute the difference against the new value of jiffies when the tick is restarted. Then we account this whole difference to the idle cputime. However we are preparing to be able to stop the tick from other places than idle. So this idle time accounting needs to be performed from the callers of nohz APIs, not from the nohz APIs themselves because we now want them to be agnostic against places that stop/restart tick. Therefore, we pull the tickless idle time accounting out of generic nohz helpers up to idle entry/exit callers. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-11nohz: Separate idle sleeping time accounting from nohz logicFrederic Weisbecker
As we plan to be able to stop the tick outside the idle task, we need to prepare for separating nohz logic from idle. As a start, this pulls the idle sleeping time accounting out of the tick stop/restart API to the callers on idle entry/exit. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-11smpboot: Remove leftover declarationThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-06-11Merge tag 'v3.5-rc2' into perf/coreIngo Molnar
Merge in Linux 3.5-rc2 - to pick up fixes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-11Merge branch 'rcu/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent Merge RCU fixes from Paul E. McKenney: " This series has four patches, the major point of which is to eliminate some slowdowns (including boot-time slowdowns) resulting from some RCU_FAST_NO_HZ changes. The issue with the changes is that posting timers from the idle loop has no effect if the CPU has entered dyntick-idle mode because the CPU has already computed its wakeup time, and posting a timer does not cause it to be recomputed. The short-term fix is for RCU to precompute the timeout value so that the CPU's calculation is correct. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar. * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix the relax_domain_level boot parameter sched: Validate assumptions in sched_init_numa() sched: Always initialize cpu-power sched: Fix domain iteration sched/rt: Fix lockdep annotation within find_lock_lowest_rq() sched/numa: Load balance between remote nodes sched/x86: Calculate booted cores after construction of sibling_mask
2012-06-08sched/fair: fix lots of kernel-doc warningsRandy Dunlap
Fix lots of new kernel-doc warnings in kernel/sched/fair.c: Warning(kernel/sched/fair.c:3625): No description found for parameter 'env' Warning(kernel/sched/fair.c:3625): Excess function parameter 'sd' description in 'update_sg_lb_stats' Warning(kernel/sched/fair.c:3735): No description found for parameter 'env' Warning(kernel/sched/fair.c:3735): Excess function parameter 'sd' description in 'update_sd_pick_busiest' Warning(kernel/sched/fair.c:3735): Excess function parameter 'this_cpu' description in 'update_sd_pick_busiest' .. more warnings Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-08Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "A bit larger than what I'd wish for - half of it is due to hw driver updates to Intel Ivy-Bridge which info got recently released, cycles:pp should work there now too, amongst other things. (but we are generally making exceptions for hardware enablement of this type.) There are also callchain fixes in it - responding to mostly theoretical (but valid) concerns. The tooling side sports perf.data endianness/portability fixes which did not make it for the merge window - and various other fixes as well." * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) perf/x86: Check user address explicitly in copy_from_user_nmi() perf/x86: Check if user fp is valid perf: Limit callchains to 127 perf/x86: Allow multiple stacks perf/x86: Update SNB PEBS constraints perf/x86: Enable/Add IvyBridge hardware support perf/x86: Implement cycles:p for SNB/IVB perf/x86: Fix Intel shared extra MSR allocation x86/decoder: Fix bsr/bsf/jmpe decoding with operand-size prefix perf: Remove duplicate invocation on perf_event_for_each perf uprobes: Remove unnecessary check before strlist__delete perf symbols: Check for valid dso before creating map perf evsel: Fix 32 bit values endianity swap for sample_id_all header perf session: Handle endianity swap on sample_id_all header data perf symbols: Handle different endians properly during symbol load perf evlist: Pass third argument to ioctl explicitly perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP perf tools: Make --version show kernel version instead of pull req tag perf tools: Check if callchain is corrupted perf callchain: Make callchain cursors TLS ...
2012-06-08Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull leap second timer fix from Thomas Gleixner. * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond
2012-06-08Merge branch 'tip/perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull brown paper bag fix from Steve Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08uprobes: Pass probed vaddr to arch_uprobe_analyze_insn()Ananth N Mavinakayanahalli
On RISC architectures like powerpc, instructions are fixed size. Instruction analysis on such platforms is just a matter of (insn % 4). Pass the vaddr at which the uprobe is to be inserted so that arch_uprobe_analyze_insn() can flag misaligned registration requests. Signed-off-by: Ananth N Mavinakaynahalli <ananth@in.ibm.com> Cc: michael@ellerman.id.au Cc: antonb@thinktux.localdomain Cc: Paul Mackerras <paulus@samba.org> Cc: benh@kernel.crashing.org Cc: peterz@infradead.org Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: oleg@redhat.com Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20120608093257.GG13409@in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-07Revert "mm: correctly synchronize rss-counters at exit/exec"Linus Torvalds
This reverts commit 40af1bbdca47e5c8a2044039bb78ca8fd8b20f94. It's horribly and utterly broken for at least the following reasons: - calling sync_mm_rss() from mmput() is fundamentally wrong, because there's absolutely no reason to believe that the task that does the mmput() always does it on its own VM. Example: fork, ptrace, /proc - you name it. - calling it *after* having done mmdrop() on it is doubly insane, since the mm struct may well be gone now. - testing mm against NULL before you call it is insane too, since a NULL mm there would have caused oopses long before. .. and those are just the three bugs I found before I decided to give up looking for me and revert it asap. I should have caught it before I even took it, but I trusted Andrew too much. Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07mm: correctly synchronize rss-counters at exit/execKonstantin Khlebnikov
mm->rss_stat counters have per-task delta: task->rss_stat. Before changing task->mm pointer the kernel must flush this delta with sync_mm_rss(). do_exit() already calls sync_mm_rss() to flush the rss-counters before committing the rss statistics into task->signal->maxrss, taskstats, audit and other stuff. Unfortunately the kernel does this before calling mm_release(), which can call put_user() for processing task->clear_child_tid. So at this point we can trigger page-faults and task->rss_stat becomes non-zero again. As a result mm->rss_stat becomes inconsistent and check_mm() will print something like this: | BUG: Bad rss-counter state mm:ffff88020813c380 idx:1 val:-1 | BUG: Bad rss-counter state mm:ffff88020813c380 idx:2 val:1 This patch moves sync_mm_rss() into mm_release(), and moves mm_release() out of do_exit() and calls it earlier. After mm_release() there should be no pagefaults. [akpm@linux-foundation.org: tweak comment] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> [3.4.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: drop VMA flags test on PR_SET_MM_ stack data assignmentCyrill Gorcunov
In commit b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") the stack allocated via clone() is marked in /proc/<pid>/maps as [stack:%d] thus it might be out of the former mm->start_stack/end_stack values (and even has some custom VMA flags set). So to be able to restore mm->start_stack/end_stack drop vma flags test, but still require the underlying VMA to exist. As always note this feature is under CONFIG_CHECKPOINT_RESTORE and requires CAP_SYS_RESOURCE to be granted. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: add ability to get clear_tid_addressCyrill Gorcunov
Zero is written at clear_tid_address when the process exits. This functionality is used by pthread_join(). We already have sys_set_tid_address() to change this address for the current task but there is no way to obtain it from user space. Without the ability to find this address and dump it we can't restore pthread'ed apps which call pthread_join() once they have been restored. This patch introduces the PR_GET_TID_ADDRESS prctl option which allows the current process to obtain own clear_tid_address. This feature is available iif CONFIG_CHECKPOINT_RESTORE is set. [akpm@linux-foundation.org: fix prctl numbering] Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pedro Alves <palves@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>