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2014-10-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds8-7/+2782
Pull networking updates from David Miller: "Most notable changes in here: 1) By far the biggest accomplishment, thanks to a large range of contributors, is the addition of multi-send for transmit. This is the result of discussions back in Chicago, and the hard work of several individuals. Now, when the ->ndo_start_xmit() method of a driver sees skb->xmit_more as true, it can choose to defer the doorbell telling the driver to start processing the new TX queue entires. skb->xmit_more means that the generic networking is guaranteed to call the driver immediately with another SKB to send. There is logic added to the qdisc layer to dequeue multiple packets at a time, and the handling mis-predicted offloads in software is now done with no locks held. Finally, pktgen is extended to have a "burst" parameter that can be used to test a multi-send implementation. Several drivers have xmit_more support: i40e, igb, ixgbe, mlx4, virtio_net Adding support is almost trivial, so export more drivers to support this optimization soon. I want to thank, in no particular or implied order, Jesper Dangaard Brouer, Eric Dumazet, Alexander Duyck, Tom Herbert, Jamal Hadi Salim, John Fastabend, Florian Westphal, Daniel Borkmann, David Tat, Hannes Frederic Sowa, and Rusty Russell. 2) PTP and timestamping support in bnx2x, from Michal Kalderon. 3) Allow adjusting the rx_copybreak threshold for a driver via ethtool, and add rx_copybreak support to enic driver. From Govindarajulu Varadarajan. 4) Significant enhancements to the generic PHY layer and the bcm7xxx driver in particular (EEE support, auto power down, etc.) from Florian Fainelli. 5) Allow raw buffers to be used for flow dissection, allowing drivers to determine the optimal "linear pull" size for devices that DMA into pools of pages. The objective is to get exactly the necessary amount of headers into the linear SKB area pre-pulled, but no more. The new interface drivers use is eth_get_headlen(). From WANG Cong, with driver conversions (several had their own by-hand duplicated implementations) by Alexander Duyck and Eric Dumazet. 6) Support checksumming more smoothly and efficiently for encapsulations, and add "foo over UDP" facility. From Tom Herbert. 7) Add Broadcom SF2 switch driver to DSA layer, from Florian Fainelli. 8) eBPF now can load programs via a system call and has an extensive testsuite. Alexei Starovoitov and Daniel Borkmann. 9) Major overhaul of the packet scheduler to use RCU in several major areas such as the classifiers and rate estimators. From John Fastabend. 10) Add driver for Intel FM10000 Ethernet Switch, from Alexander Duyck. 11) Rearrange TCP_SKB_CB() to reduce cache line misses, from Eric Dumazet. 12) Add Datacenter TCP congestion control algorithm support, From Florian Westphal. 13) Reorganize sk_buff so that __copy_skb_header() is significantly faster. From Eric Dumazet" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1558 commits) netlabel: directly return netlbl_unlabel_genl_init() net: add netdev_txq_bql_{enqueue, complete}_prefetchw() helpers net: description of dma_cookie cause make xmldocs warning cxgb4: clean up a type issue cxgb4: potential shift wrapping bug i40e: skb->xmit_more support net: fs_enet: Add NAPI TX net: fs_enet: Remove non NAPI RX r8169:add support for RTL8168EP net_sched: copy exts->type in tcf_exts_change() wimax: convert printk to pr_foo() af_unix: remove 0 assignment on static ipv6: Do not warn for informational ICMP messages, regardless of type. Update Intel Ethernet Driver maintainers list bridge: Save frag_max_size between PRE_ROUTING and POST_ROUTING tipc: fix bug in multicast congestion handling net: better IFF_XMIT_DST_RELEASE support net/mlx4_en: remove NETDEV_TX_BUSY 3c59x: fix bad split of cpu_to_le32(pci_map_single()) net: bcmgenet: fix Tx ring priority programming ...
2014-10-09tracing: Robustify wait loopPeter Zijlstra1-1/+4
The pending nested sleep debugging triggered on the potential stale TASK_INTERRUPTIBLE in this code. While there, fix the loop such that we won't revert to a while(1) yield() 'spin' loop if we ever get a spurious wakeup. And fix the actual issue by properly terminating the 'wait' loop by setting TASK_RUNNING. Link: http://lkml.kernel.org/p/20141008165110.GA14547@worktop.programming.kicks-ass.net Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-10-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-3/+6
2014-10-08Merge tag 'nfs-for-3.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds1-0/+36
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - fix an NFSv4.1 state renewal regression - fix open/lock state recovery error handling - fix lock recovery when CREATE_SESSION/SETCLIENTID_CONFIRM fails - fix statd when reconnection fails - don't wake tasks during connection abort - don't start reboot recovery if lease check fails - fix duplicate proc entries Features: - pNFS block driver fixes and clean ups from Christoph - More code cleanups from Anna - Improve mmap() writeback performance - Replace use of PF_TRANS with a more generic mechanism for avoiding deadlocks in nfs_release_page" * tag 'nfs-for-3.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (66 commits) NFSv4.1: Fix an NFSv4.1 state renewal regression NFSv4: fix open/lock state recovery error handling NFSv4: Fix lock recovery when CREATE_SESSION/SETCLIENTID_CONFIRM fails NFS: Fabricate fscache server index key correctly SUNRPC: Add missing support for RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT NFSv3: Fix missing includes of nfs3_fs.h NFS/SUNRPC: Remove other deadlock-avoidance mechanisms in nfs_release_page() NFS: avoid waiting at all in nfs_release_page when congested. NFS: avoid deadlocks with loop-back mounted NFS filesystems. MM: export page_wakeup functions SCHED: add some "wait..on_bit...timeout()" interfaces. NFS: don't use STABLE writes during writeback. NFSv4: use exponential retry on NFS4ERR_DELAY for async requests. rpc: Add -EPERM processing for xs_udp_send_request() rpc: return sent and err from xs_sendpages() lockd: Try to reconnect if statd has moved SUNRPC: Don't wake tasks during connection abort Fixing lease renewal nfs: fix duplicate proc entries pnfs/blocklayout: Fix a 64-bit division/remainder issue in bl_map_stripe ...
2014-10-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds1-0/+12
Pull crypto update from Herbert Xu: - add multibuffer infrastructure (single_task_running scheduler helper, OKed by Peter on lkml. - add SHA1 multibuffer implementation for AVX2. - reenable "by8" AVX CTR optimisation after fixing counter overflow. - add APM X-Gene SoC RNG support. - SHA256/SHA512 now handles unaligned input correctly. - set lz4 decompressed length correctly. - fix algif socket buffer allocation failure for 64K page machines. - misc fixes * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (47 commits) crypto: sha - Handle unaligned input data in generic sha256 and sha512. Revert "crypto: aesni - disable "by8" AVX CTR optimization" crypto: aesni - remove unused defines in "by8" variant crypto: aesni - fix counter overflow handling in "by8" variant hwrng: printk replacement crypto: qat - Removed unneeded partial state crypto: qat - Fix typo in name of tasklet_struct crypto: caam - Dynamic allocation of addresses for various memory blocks in CAAM. crypto: mcryptd - Fix typos in CRYPTO_MCRYPTD description crypto: algif - avoid excessive use of socket buffer in skcipher arm64: dts: add random number generator dts node to APM X-Gene platform. Documentation: rng: Add X-Gene SoC RNG driver documentation hwrng: xgene - add support for APM X-Gene SoC RNG support crypto: mv_cesa - Add missing #define crypto: testmgr - add test for lz4 and lz4hc crypto: lz4,lz4hc - fix decompression crypto: qat - Use pci_enable_msix_exact() instead of pci_enable_msix() crypto: drbg - fix maximum value checks on 32 bit systems crypto: drbg - fix sparse warning for cpu_to_be[32|64] crypto: sha-mb - sha1_mb_alg_state can be static ...
2014-10-08Merge tag 'arm64-upstream' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - eBPF JIT compiler for arm64 - CPU suspend backend for PSCI (firmware interface) with standard idle states defined in DT (generic idle driver to be merged via a different tree) - Support for CONFIG_DEBUG_SET_MODULE_RONX - Support for unmapped cpu-release-addr (outside kernel linear mapping) - set_arch_dma_coherent_ops() implemented and bus notifiers removed - EFI_STUB improvements when base of DRAM is occupied - Typos in KGDB macros - Clean-up to (partially) allow kernel building with LLVM - Other clean-ups (extern keyword, phys_addr_t usage) * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (51 commits) arm64: Remove unneeded extern keyword ARM64: make of_device_ids const arm64: Use phys_addr_t type for physical address aarch64: filter $x from kallsyms arm64: Use DMA_ERROR_CODE to denote failed allocation arm64: Fix typos in KGDB macros arm64: insn: Add return statements after BUG_ON() arm64: debug: don't re-enable debug exceptions on return from el1_dbg Revert "arm64: dmi: Add SMBIOS/DMI support" arm64: Implement set_arch_dma_coherent_ops() to replace bus notifiers of: amba: use of_dma_configure for AMBA devices arm64: dmi: Add SMBIOS/DMI support arm64: Correct ftrace calls to aarch64_insn_gen_branch_imm() arm64:mm: initialize max_mapnr using function set_max_mapnr setup: Move unmask of async interrupts after possible earlycon setup arm64: LLVMLinux: Fix inline arm64 assembly for use with clang arm64: pageattr: Correctly adjust unaligned start addresses net: bpf: arm64: fix module memory leak when JIT image build fails arm64: add PSCI CPU_SUSPEND based cpu_suspend support arm64: kernel: introduce cpu_init_idle CPU operation ...
2014-10-08Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds1-1/+1
Pull ARM updates from Russell King: "Included in these updates are: - Performance optimisation to avoid writing the control register at every exception. - Use static inline instead of extern inline in ftrace code. - Crypto ARM assembly updates for big endian - Alignment of initrd/.init memory to page sizes when freeing to ensure that we fully free the regions - Add gcov support - A couple of preparatory patches for VDSO support: use _install_special_mapping, and randomize the sigpage placement above stack. - Add L2 ePAPR DT cache properties so that DT can specify the cache geometry. - Preparatory patch for FIQ (NMI) kernel C code for things like spinlock lockup debug. Following on from this are a couple of my patches cleaning up show_regs() and removing an unused (probably since 1.x days) do_unexp_fiq() function. - Use pr_warn() rather than pr_warning(). - A number of cleanups (smp, footbridge, return_address)" * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (21 commits) ARM: 8167/1: extend the reserved memory for initrd to be page aligned ARM: 8168/1: extend __init_end to a page align address ARM: 8169/1: l2c: parse cache properties from ePAPR definitions ARM: 8160/1: drop warning about return_address not using unwind tables ARM: 8161/1: footbridge: select machine dir based on ARCH_FOOTBRIDGE ARM: 8158/1: LLVMLinux: use static inline in ARM ftrace.h ARM: 8155/1: place sigpage at a random offset above stack ARM: 8154/1: use _install_special_mapping for sigpage ARM: 8153/1: Enable gcov support on the ARM architecture ARM: Avoid writing to control register on every exception ARM: 8152/1: Convert pr_warning to pr_warn ARM: remove unused do_unexp_fiq() function ARM: remove extraneous newline in show_regs() ARM: 8150/3: fiq: Replace default FIQ handler ARM: 8140/1: ep93xx: Enable DEBUG_LL_UART_PL01X ARM: 8139/1: versatile: Enable DEBUG_LL_UART_PL01X ARM: 8138/1: drop ISAR0 workaround for B15 ARM: 8136/1: sa1100: add Micro ASIC platform device ARM: 8131/1: arm/smp: Absorb boot_secondary() ARM: 8126/1: crypto: enable NEON SHA-384/SHA-512 for big endian ...
2014-10-08Merge branch 'for-linus' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull "trivial tree" updates from Jiri Kosina: "Usual pile from trivial tree everyone is so eagerly waiting for" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) Remove MN10300_PROC_MN2WS0038 mei: fix comments treewide: Fix typos in Kconfig kprobes: update jprobe_example.c for do_fork() change Documentation: change "&" to "and" in Documentation/applying-patches.txt Documentation: remove obsolete pcmcia-cs from Changes Documentation: update links in Changes Documentation: Docbook: Fix generated DocBook/kernel-api.xml score: Remove GENERIC_HAS_IOMAP gpio: fix 'CONFIG_GPIO_IRQCHIP' comments tty: doc: Fix grammar in serial/tty dma-debug: modify check_for_stack output treewide: fix errors in printk genirq: fix reference in devm_request_threaded_irq comment treewide: fix synchronize_rcu() in comments checkstack.pl: port to AArch64 doc: queue-sysfs: minor fixes init/do_mounts: better syntax description MIPS: fix comment spelling powerpc/simpleboot: fix comment ...
2014-10-08Merge tag 'dmaengine-3.17' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine Pull dmaengine updates from Dan Williams: "Even though this has fixes marked for -stable, given the size and the needed conflict resolutions this is 3.18-rc1/merge-window material. These patches have been languishing in my tree for a long while. The fact that I do not have the time to do proper/prompt maintenance of this tree is a primary factor in the decision to step down as dmaengine maintainer. That and the fact that the bulk of drivers/dma/ activity is going through Vinod these days. The net_dma removal has not been in -next. It has developed simple conflicts against mainline and net-next (for-3.18). Continuing thanks to Vinod for staying on top of drivers/dma/. Summary: 1/ Step down as dmaengine maintainer see commit 08223d80df38 "dmaengine maintainer update" 2/ Removal of net_dma, as it has been marked 'broken' since 3.13 (commit 77873803363c "net_dma: mark broken"), without reports of performance regression. 3/ Miscellaneous fixes" * tag 'dmaengine-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine: net: make tcp_cleanup_rbuf private net_dma: revert 'copied_early' net_dma: simple removal dmaengine maintainer update dmatest: prevent memory leakage on error path in thread ioat: Use time_before_jiffies() dmaengine: fix xor sources continuation dma: mv_xor: Rename __mv_xor_slot_cleanup() to mv_xor_slot_cleanup() dma: mv_xor: Remove all callers of mv_xor_slot_cleanup() dma: mv_xor: Remove unneeded mv_xor_clean_completed_slots() call ioat: Use pci_enable_msix_exact() instead of pci_enable_msix() drivers: dma: Include appropriate header file in dca.c drivers: dma: Mark functions as static in dma_v3.c dma: mv_xor: Add DMA API error checks ioat/dca: Use dev_is_pci() to check whether it is pci device
2014-10-08Merge tag 'modules-next-for-linus' of ↵Linus Torvalds2-4/+15
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module update from Rusty Russell: "Nothing major: support for compressing modules, and auto-tainting params. PS. My virtio-next tree is empty: DaveM took the patches I had. There might be a virtio-rng starvation fix, but so far it's a bit voodoo so I will get to that in the next two days or it will wait" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: moduleparam: Resolve missing-field-initializer warning kbuild: handle module compression while running 'make modules_install'. modinst: wrap long lines in order to enhance cmd_modules_install modsign: lookup lines ending in .ko in .mod files modpost: simplify file name generation of *.mod.c files modpost: reduce visibility of symbols and constify r/o arrays param: check for tainting before calling set op. drm/i915: taint the kernel if unsafe module parameters are set module: add module_param_unsafe and module_param_named_unsafe module: make it possible to have unsafe, tainting module params module: rename KERNEL_PARAM_FL_NOARG to avoid confusion
2014-10-07Merge tag 'tiny/for-3.18' of ↵Linus Torvalds2-0/+7
git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux Pull "tinification" patches from Josh Triplett. Work on making smaller kernels. * tag 'tiny/for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux: bloat-o-meter: Ignore syscall aliases SyS_ and compat_SyS_ mm: Support compiling out madvise and fadvise x86: Support compiling out human-friendly processor feature names x86: Drop support for /proc files when !CONFIG_PROC_FS x86, boot: Don't compile early_serial_console.c when !CONFIG_EARLY_PRINTK x86, boot: Don't compile aslr.c when !CONFIG_RANDOMIZE_BASE x86, boot: Use the usual -y -n mechanism for objects in vmlinux x86: Add "make tinyconfig" to configure the tiniest possible kernel x86, platform, kconfig: move kvmconfig functionality to a helper
2014-10-07Merge branch 'pm-domains'Rafael J. Wysocki1-0/+4
* pm-domains: (32 commits) PM / Domains: Rename cpu_data to cpuidle_data PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h PM / Domains: Remove legacy API for adding devices through DT PM / Domains: Add genpd attach/detach callbacks PM / Domains: add debugfs listing of struct generic_pm_domain-s ACPI / PM: Convert acpi_dev_pm_detach() into a static function ARM: exynos: Move to generic PM domain DT bindings amba: Add support for attach/detach of PM domains spi: core: Convert to dev_pm_domain_attach|detach() mmc: sdio: Convert to dev_pm_domain_attach|detach() i2c: core: Convert to dev_pm_domain_attach|detach() drivercore / platform: Convert to dev_pm_domain_attach|detach() PM / Domains: Add APIs to attach/detach a PM domain for a device PM / Domains: Add generic OF-based PM domain look-up ACPI / PM: Assign the ->detach() callback when attaching the PM domain PM / Domains: Add a detach callback to the struct dev_pm_domain PM / domains: Spelling s/domian/domain/ PM / domains: Keep declaration of dev_power_governors together PM / domains: Remove default_stop_ok() API drivers: sh: Leave disabling of unused PM domains to genpd ...
2014-10-07Merge branch 'acpi-pm'Rafael J. Wysocki1-11/+38
* acpi-pm: ACPI / sleep: Rework the handling of ACPI GPE wakeup from suspend-to-idle PM / sleep: Rename platform suspend/resume functions in suspend.c PM / sleep: Export dpm_suspend_late/noirq() and dpm_resume_early/noirq()
2014-10-07Merge branch 'pm-sleep'Rafael J. Wysocki3-18/+70
* pm-sleep: PM / hibernate: Iterate over set bits instead of PFNs in swsusp_free() PM / sleep: new suspend_resume trace event for console resume PM / sleep: Update test_suspend option documentation PM / sleep: Enhance test_suspend option with repeat capability PM / sleep: Support freeze as test_suspend option PM / sysfs: avoid shadowing variables
2014-10-07Merge branch 'pm-genirq'Rafael J. Wysocki5-97/+196
* pm-genirq: PM / genirq: Document rules related to system suspend and interrupts PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle x86 / PM: Set IRQCHIP_SKIP_SET_WAKE for IOAPIC IRQ chip objects genirq: Simplify wakeup mechanism genirq: Mark wakeup sources as armed on suspend genirq: Create helper for flow handler entry check genirq: Distangle edge handler entry genirq: Avoid double loop on suspend genirq: Move MASK_ON_SUSPEND handling into suspend_device_irqs() genirq: Make use of pm misfeature accounting genirq: Add sanity checks for PM options on shared interrupt lines genirq: Move suspend/resume logic into irq/pm code PM / sleep: Mechanism for aborting system suspends unconditionally
2014-10-06workqueue: Use cond_resched_rcu_qs macroJoe Lawrence1-2/+1
Tidy up and use cond_resched_rcu_qs when calling cond_resched and reporting potential quiescent state to RCU. Splitting this change in this way allows easy backporting to -stable for kernel versions not having cond_resched_rcu_qs(). Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-10-06workqueue: Add quiescent state between work itemsJoe Lawrence1-1/+3
Similar to the stop_machine deadlock scenario on !PREEMPT kernels addressed in b22ce2785d97 "workqueue: cond_resched() after processing each work item", kworker threads requeueing back-to-back with zero jiffy delay can stall RCU. The cond_resched call introduced in that fix will yield only iff there are other higher priority tasks to run, so force a quiescent RCU state between work items. Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Link: https://lkml.kernel.org/r/20140926105227.01325697@jlaw-desktop.mno.stratus.com Link: https://lkml.kernel.org/r/20140929115445.40221d8e@jlaw-desktop.mno.stratus.com Fixes: b22ce2785d97 ("workqueue: cond_resched() after processing each work item") Cc: <stable@vger.kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-10-04Merge tag 'trace-fixes-v3.17-rc7' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull trace ring buffer iterator fix from Steven Rostedt: "While testing some new changes for 3.18, I kept hitting a bug every so often in the ring buffer. At first I thought it had to do with some of the changes I was working on, but then testing something else I realized that the bug was in 3.17 itself. I ran several bisects as the bug was not very reproducible, and finally came up with the commit that I could reproduce easily within a few minutes, and without the change I could run the tests over an hour without issue. The change fit the bug and I figured out a fix. That bad commit was: Commit 651e22f2701b "ring-buffer: Always reset iterator to reader page" This commit fixed a bug, but in the process created another one. It used the wrong value as the cached value that is used to see if things changed while an iterator was in use. This made it look like a change always happened, and could cause the iterator to go into an infinite loop" * tag 'trace-fixes-v3.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Fix infinite spin in reading buffer
2014-10-03locking/lockdep: Revert qrwlock recusive stuffPeter Zijlstra1-6/+0
Commit f0bab73cb539 ("locking/lockdep: Restrict the use of recursive read_lock() with qrwlock") changed lockdep to try and conform to the qrwlock semantics which differ from the traditional rwlock semantics. In particular qrwlock is fair outside of interrupt context, but in interrupt context readers will ignore all fairness. The problem modeling this is that read and write side have different lock state (interrupts) semantics but we only have a single representation of these. Therefore lockdep will get confused, thinking the lock can cause interrupt lock inversions. So revert it for now; the old rwlock semantics were already imperfectly modeled and the qrwlock extra won't fit either. If we want to properly fix this, I think we need to resurrect the work by Gautham did a few years ago that split the read and write state of locks: http://lwn.net/Articles/332801/ FWIW the locking selftest that would've failed (and was reported by Borislav earlier) is something like: RL(X1); /* IRQ-ON */ LOCK(A); UNLOCK(A); RU(X1); IRQ_ENTER(); RL(X1); /* IN-IRQ */ RU(X1); IRQ_EXIT(); At which point it would report that because A is an IRQ-unsafe lock we can suffer the following inversion: CPU0 CPU1 lock(A) lock(X1) lock(A) <IRQ> lock(X1) And this is 'wrong' because X1 can recurse (assuming the above lock are in fact read-lock) but lockdep doesn't know about this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Waiman Long <Waiman.Long@hp.com> Cc: ego@linux.vnet.ibm.com Cc: bp@alien8.de Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20140930132600.GA7444@worktop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03locking/rwsem: Avoid double checking before try acquiring write lockJason Low1-9/+11
Commit 9b0fc9c09f1b ("rwsem: skip initial trylock in rwsem_down_write_failed") checks for if there are known active lockers in order to avoid write trylocking using expensive cmpxchg() when it likely wouldn't get the lock. However, a subsequent patch was added such that we directly check for sem->count == RWSEM_WAITING_BIAS right before trying that cmpxchg(). Thus, commit 9b0fc9c09f1b now just adds overhead. This patch modifies it so that we only do a check for if count == RWSEM_WAITING_BIAS. Also, add a comment on why we do an "extra check" of count before the cmpxchg(). Signed-off-by: Jason Low <jason.low2@hp.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Chegu Vinod <chegu_vinod@hp.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1410913017.2447.22.camel@j-VirtualBox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03sched/dl: Use dl_bw_of() under rcu_read_lock_sched()Kirill Tkhai1-9/+16
rq->rd is freed using call_rcu_sched(), so rcu_read_lock() to access it is not enough. We should use either rcu_read_lock_sched() or preempt_disable(). Reported-by: Sasha Levin <sasha.levin@oracle.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kirill Tkhai <ktkhai@parallels.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Fixes: 66339c31bc39 "sched: Use dl_bw_of() under RCU read lock" Link: http://lkml.kernel.org/r/1412065417.20287.24.camel@tkhai Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03sched/fair: Delete resched_cpu() from idle_balance()Kirill Tkhai1-6/+0
We already reschedule env.dst_cpu in attach_tasks()->check_preempt_curr() if this is necessary. Furthermore, a higher priority class task may be current on dest rq, we shouldn't disturb it. Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> Cc: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140930210441.5258.55054.stgit@localhost Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03sched, time: Fix build error with 64 bit cputime_t on 32 bit systemsRik van Riel1-10/+19
On 32 bit systems cmpxchg cannot handle 64 bit values, so some additional magic is required to allow a 32 bit system with CONFIG_VIRT_CPU_ACCOUNTING_GEN=y enabled to build. Make sure the correct cmpxchg function is used when doing an atomic swap of a cputime_t. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: umgwanakikbuti@gmail.com Cc: fweisbec@gmail.com Cc: srao@redhat.com Cc: lwoodman@redhat.com Cc: atheurer@redhat.com Cc: oleg@redhat.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: linux390@de.ibm.com Cc: linux-arch@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Link: http://lkml.kernel.org/r/20140930155947.070cdb1f@annuminas.surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03sched: Improve sysbench performance by fixing spurious active migrationVincent Guittot1-6/+7
Since commit caeb178c60f4 ("sched/fair: Make update_sd_pick_busiest() ...") sd_pick_busiest returns a group that can be neither imbalanced nor overloaded but is only more loaded than others. This change has been introduced to ensure a better load balance in system that are not overloaded but as a side effect, it can also generate useless active migration between groups. Let take the example of 3 tasks on a quad cores system. We will always have an idle core so the load balance will find a busiest group (core) whenever an ILB is triggered and it will force an active migration (once above nr_balance_failed threshold) so the idle core becomes busy but another core will become idle. With the next ILB, the freshly idle core will try to pull the task of a busy CPU. The number of spurious active migration is not so huge in quad core system because the ILB is not triggered so much. But it becomes significant as soon as you have more than one sched_domain level like on a dual cluster of quad cores where the ILB is triggered every tick when you have more than 1 busy_cpu We need to ensure that the migration generate a real improveùent and will not only move the avg_load imbalance on another CPU. Before caeb178c60f4f93f1b45c0bc056b5cf6d217b67f, the filtering of such use case was ensured by the following test in f_b_g: if ((local->idle_cpus < busiest->idle_cpus) && busiest->sum_nr_running <= busiest->group_weight) This patch modified the condition to take into account situation where busiest group is not overloaded: If the diff between the number of idle cpus in 2 groups is less than or equal to 1 and the busiest group is not overloaded, moving a task will not improve the load balance but just move it. A test with sysbench on a dual clusters of quad cores gives the following results: command: sysbench --test=cpu --num-threads=5 --max-time=5 run The HZ is 200 which means that 1000 ticks has fired during the test. With Mainline, perf gives the following figures: Samples: 727 of event 'sched:sched_migrate_task' Event count (approx.): 727 Overhead Command Shared Object Symbol ........ ............... ............. .............. 12.52% migration/1 [unknown] [.] 00000000 12.52% migration/5 [unknown] [.] 00000000 12.52% migration/7 [unknown] [.] 00000000 12.10% migration/6 [unknown] [.] 00000000 11.83% migration/0 [unknown] [.] 00000000 11.83% migration/3 [unknown] [.] 00000000 11.14% migration/4 [unknown] [.] 00000000 10.87% migration/2 [unknown] [.] 00000000 2.75% sysbench [unknown] [.] 00000000 0.83% swapper [unknown] [.] 00000000 0.55% ktps65090charge [unknown] [.] 00000000 0.41% mmcqd/1 [unknown] [.] 00000000 0.14% perf [unknown] [.] 00000000 With this patch, perf gives the following figures Samples: 20 of event 'sched:sched_migrate_task' Event count (approx.): 20 Overhead Command Shared Object Symbol ........ ............... ............. .............. 80.00% sysbench [unknown] [.] 00000000 10.00% swapper [unknown] [.] 00000000 5.00% ktps65090charge [unknown] [.] 00000000 5.00% migration/1 [unknown] [.] 00000000 Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1412170735-5356-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03perf: Fix perf bug in fork()Peter Zijlstra2-3/+6
Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by calling perf_event_free_task() when failing sched_fork() we will not yet have done the memset() on ->perf_event_ctxp[] and will therefore try and 'free' the inherited contexts, which are still in use by the parent process. This is bad and might explain some outstanding fuzzer failures ... Suggested-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daeseok Youn <daeseok.youn@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rik van Riel <riel@redhat.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20140929101201.GE5430@worktop Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03perf: Fix unclone_ctx() vs. lockingPeter Zijlstra1-23/+31
The idiot who did 4a1c0f262f88 ("perf: Fix lockdep warning on process exit") forgot to pay attention and fix all similar cases. Do so now. In particular, unclone_ctx() must be called while holding ctx->lock, therefore all such sites are broken for the same reason. Pull the put_ctx() call out from under ctx->lock. Reported-by: Sasha Levin <sasha.levin@oracle.com> Probably-also-reported-by: Vince Weaver <vincent.weaver@maine.edu> Fixes: 4a1c0f262f88 ("perf: Fix lockdep warning on process exit") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Cong Wang <cwang@twopensource.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140930172308.GI4241@worktop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03perf: fix perf bug in fork()Peter Zijlstra2-3/+6
Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by calling perf_event_free_task() when failing sched_fork() we will not yet have done the memset() on ->perf_event_ctxp[] and will therefore try and 'free' the inherited contexts, which are still in use by the parent process. This is bad.. Suggested-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-03ring-buffer: Fix infinite spin in reading bufferSteven Rostedt (Red Hat)1-1/+1
Commit 651e22f2701b "ring-buffer: Always reset iterator to reader page" fixed one bug but in the process caused another one. The reset is to update the header page, but that fix also changed the way the cached reads were updated. The cache reads are used to test if an iterator needs to be updated or not. A ring buffer iterator, when created, disables writes to the ring buffer but does not stop other readers or consuming reads from happening. Although all readers are synchronized via a lock, they are only synchronized when in the ring buffer functions. Those functions may be called by any number of readers. The iterator continues down when its not interrupted by a consuming reader. If a consuming read occurs, the iterator starts from the beginning of the buffer. The way the iterator sees that a consuming read has happened since its last read is by checking the reader "cache". The cache holds the last counts of the read and the reader page itself. Commit 651e22f2701b changed what was saved by the cache_read when the rb_iter_reset() occurred, making the iterator never match the cache. Then if the iterator calls rb_iter_reset(), it will go into an infinite loop by checking if the cache doesn't match, doing the reset and retrying, just to see that the cache still doesn't match! Which should never happen as the reset is suppose to set the cache to the current value and there's locks that keep a consuming reader from having access to the data. Fixes: 651e22f2701b "ring-buffer: Always reset iterator to reader page" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-10-03Merge branches 'fiq' (early part), 'fixes', 'l2c' (early part) and 'misc' ↵Russell King5-41/+31
into for-next
2014-10-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-39/+20
Conflicts: drivers/net/usb/r8152.c net/netfilter/nfnetlink.c Both r8152 and nfnetlink conflicts were simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-02aarch64: filter $x from kallsymsKyle McMartin1-1/+1
Similar to ARM, AArch64 is generating $x and $d syms... which isn't terribly helpful when looking at %pF output and the like. Filter those out in kallsyms, modpost and when looking at module symbols. Seems simplest since none of these check EM_ARM anyway, to just add it to the strchr used, rather than trying to make things overly complicated. initcall_debug improves: dmesg_before.txt: initcall $x+0x0/0x154 [sg] returned 0 after 26331 usecs dmesg_after.txt: initcall init_sg+0x0/0x154 [sg] returned 0 after 15461 usecs Signed-off-by: Kyle McMartin <kyle@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-10-02bpf: add search pruning optimization to verifierAlexei Starovoitov1-0/+146
consider C program represented in eBPF: int filter(int arg) { int a, b, c, *ptr; if (arg == 1) ptr = &a; else if (arg == 2) ptr = &b; else ptr = &c; *ptr = 0; return 0; } eBPF verifier has to follow all possible paths through the program to recognize that '*ptr = 0' instruction would be safe to execute in all situations. It's doing it by picking a path towards the end and observes changes to registers and stack at every insn until it reaches bpf_exit. Then it comes back to one of the previous branches and goes towards the end again with potentially different values in registers. When program has a lot of branches, the number of possible combinations of branches is huge, so verifer has a hard limit of walking no more than 32k instructions. This limit can be reached and complex (but valid) programs could be rejected. Therefore it's important to recognize equivalent verifier states to prune this depth first search. Basic idea can be illustrated by the program (where .. are some eBPF insns): 1: .. 2: if (rX == rY) goto 4 3: .. 4: .. 5: .. 6: bpf_exit In the first pass towards bpf_exit the verifier will walk insns: 1, 2, 3, 4, 5, 6 Since insn#2 is a branch the verifier will remember its state in verifier stack to come back to it later. Since insn#4 is marked as 'branch target', the verifier will remember its state in explored_states[4] linked list. Once it reaches insn#6 successfully it will pop the state recorded at insn#2 and will continue. Without search pruning optimization verifier would have to walk 4, 5, 6 again, effectively simulating execution of insns 1, 2, 4, 5, 6 With search pruning it will check whether state at #4 after jumping from #2 is equivalent to one recorded in explored_states[4] during first pass. If there is an equivalent state, verifier can prune the search at #4 and declare this path to be safe as well. In other words two states at #4 are equivalent if execution of 1, 2, 3, 4 insns and 1, 2, 4 insns produces equivalent registers and stack. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30PM / hibernate: Iterate over set bits instead of PFNs in swsusp_free()Joerg Roedel1-15/+39
The existing implementation of swsusp_free iterates over all pfns in the system and checks every bit in the two memory bitmaps. This doesn't scale very well with large numbers of pfns, especially when the bitmaps are not populated very densly. Change the algorithm to iterate over the set bits in the bitmaps instead to make it scale better in large memory configurations. Also add a memory_bm_clear_current() helper function that clears the bit for the last position returned from the memory bitmap. This new version adds a !NULL check for the memory bitmaps before they are walked. Not doing so causes a kernel crash when the bitmaps are NULL. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-30ACPI / sleep: Rework the handling of ACPI GPE wakeup from suspend-to-idleRafael J. Wysocki1-1/+20
The ACPI GPE wakeup from suspend-to-idle is currently based on using the IRQF_NO_SUSPEND flag for the ACPI SCI, but that is problematic for a couple of reasons. First, in principle the ACPI SCI may be shared and IRQF_NO_SUSPEND does not really work well with shared interrupts. Second, it may require the ACPI subsystem to special-case the handling of device notifications depending on whether or not they are received during suspend-to-idle in some places which would lead to fragile code. Finally, it's better the handle ACPI wakeup interrupts consistently with wakeup interrupts from other sources. For this reason, remove the IRQF_NO_SUSPEND flag from the ACPI SCI and use enable_irq_wake()/disable_irq_wake() with it instead, which requires two additional platform hooks to be added to struct platform_freeze_ops. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-30PM / sleep: Rename platform suspend/resume functions in suspend.cRafael J. Wysocki1-10/+10
Rename several local functions related to platform handling during system suspend resume in suspend.c so that their names better reflect their roles. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-30PM / sleep: Export dpm_suspend_late/noirq() and dpm_resume_early/noirq()Rafael J. Wysocki1-3/+11
Subsequent change sets will add platform-related operations between dpm_suspend_late() and dpm_suspend_noirq() as well as between dpm_resume_noirq() and dpm_resume_early() in suspend_enter(), so export these functions for suspend_enter() to be able to call them separately and split the invocations of dpm_suspend_end() and dpm_resume_start() in there accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-30Merge branch 'pm-genirq' into acpi-pmRafael J. Wysocki5-97/+196
2014-09-30locktorture: Cleanup header usageDavidlohr Bueso1-13/+1
Remove some unnecessary ones and explicitly include rwsem.h Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-30locktorture: Cannot hold read and write lockDavidlohr Bueso1-0/+10
... trigger an error if so. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-30locktorture: Fix __acquire annotation for spinlock irqDavidlohr Bueso1-1/+1
Its quite easy to get mixed up with the names -- 'torture_spinlock_irq' is not actually a valid spinlock name. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-30locktorture: Support rwlocksDavidlohr Bueso1-3/+112
Add a "rw_lock" torture test to stress kernel rwlocks and their irq variant. Reader critical regions are 5x longer than writers. As such a similar ratio of lock acquisitions is seen in the statistics. In the case of massive contention, both hold the lock for 1/10 of a second. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-29Merge back earlier 'pm-sleep' material for v3.18.Rafael J. Wysocki2-3/+31
2014-09-28net_dma: simple removalDan Williams1-1/+0
Per commit "77873803363c net_dma: mark broken" net_dma is no longer used and there is no plan to fix it. This is the mechanical removal of bits in CONFIG_NET_DMA ifdef guards. Reverting the remainder of the net_dma induced changes is deferred to subsequent patches. Marked for stable due to Roman's report of a memory leak in dma_pin_iovec_pages(): https://lkml.org/lkml/2014/9/3/177 Cc: Dave Jiang <dave.jiang@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: David Whipple <whipple@securedatainnovations.ch> Cc: Alexander Duyck <alexander.h.duyck@intel.com> Cc: <stable@vger.kernel.org> Reported-by: Roman Gushchin <klamm@yandex-team.ru> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-09-28Merge branch 'for-3.17-fixes' of ↵Linus Torvalds1-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "This is quite late but these need to be backported anyway. This is the fix for a long-standing cpuset bug which existed from 2009. cpuset makes use of PF_SPREAD_{PAGE|SLAB} flags to modify the task's memory allocation behavior according to the settings of the cpuset it belongs to; unfortunately, when those flags have to be changed, cpuset did so directly even whlie the target task is running, which is obviously racy as task->flags may be modified by the task itself at any time. This obscure bug manifested as corrupt PF_USED_MATH flag leading to a weird crash. The bug is fixed by moving the flag to task->atomic_flags. The first two are prepatory ones to help defining atomic_flags accessors and the third one is the actual fix" * 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags sched: add macros to define bitops for task atomic flags sched: fix confusing PFA_NO_NEW_PRIVS constant
2014-09-26bpf: mini eBPF library, test stubs and verifier testsuiteAlexei Starovoitov2-0/+120
1. the library includes a trivial set of BPF syscall wrappers: int bpf_create_map(int key_size, int value_size, int max_entries); int bpf_update_elem(int fd, void *key, void *value); int bpf_lookup_elem(int fd, void *key, void *value); int bpf_delete_elem(int fd, void *key); int bpf_get_next_key(int fd, void *key, void *next_key); int bpf_prog_load(enum bpf_prog_type prog_type, const struct sock_filter_int *insns, int insn_len, const char *license); bpf_prog_load() stores verifier log into global bpf_log_buf[] array and BPF_*() macros to build instructions 2. test stubs configure eBPF infra with 'unspec' map and program types. These are fake types used by user space testsuite only. 3. verifier tests valid and invalid programs and expects predefined error log messages from kernel. 40 tests so far. $ sudo ./test_verifier #0 add+sub+mul OK #1 unreachable OK #2 unreachable2 OK #3 out of range jump OK #4 out of range jump2 OK #5 test1 ld_imm64 OK ... Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26bpf: verifier (add verifier core)Alexei Starovoitov1-1/+1074
This patch adds verifier core which simulates execution of every insn and records the state of registers and program stack. Every branch instruction seen during simulation is pushed into state stack. When verifier reaches BPF_EXIT, it pops the state from the stack and continues until it reaches BPF_EXIT again. For program: 1: bpf_mov r1, xxx 2: if (r1 == 0) goto 5 3: bpf_mov r0, 1 4: goto 6 5: bpf_mov r0, 2 6: bpf_exit The verifier will walk insns: 1, 2, 3, 4, 6 then it will pop the state recorded at insn#2 and will continue: 5, 6 This way it walks all possible paths through the program and checks all possible values of registers. While doing so, it checks for: - invalid instructions - uninitialized register access - uninitialized stack access - misaligned stack access - out of range stack access - invalid calling convention - instruction encoding is not using reserved fields Kernel subsystem configures the verifier with two callbacks: - bool (*is_valid_access)(int off, int size, enum bpf_access_type type); that provides information to the verifer which fields of 'ctx' are accessible (remember 'ctx' is the first argument to eBPF program) - const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id); returns argument constraints of kernel helper functions that eBPF program may call, so that verifier can checks that R1-R5 types match the prototype More details in Documentation/networking/filter.txt and in kernel/bpf/verifier.c Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26bpf: verifier (add branch/goto checks)Alexei Starovoitov1-0/+189
check that control flow graph of eBPF program is a directed acyclic graph check_cfg() does: - detect loops - detect unreachable instructions - check that program terminates with BPF_EXIT insn - check that all branches are within program boundary Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26bpf: handle pseudo BPF_LD_IMM64 insnAlexei Starovoitov1-0/+147
eBPF programs passed from userspace are using pseudo BPF_LD_IMM64 instructions to refer to process-local map_fd. Scan the program for such instructions and if FDs are valid, convert them to 'struct bpf_map' pointers which will be used by verifier to check access to maps in bpf_map_lookup/update() calls. If program passes verifier, convert pseudo BPF_LD_IMM64 into generic by dropping BPF_PSEUDO_MAP_FD flag. Note that eBPF interpreter is generic and knows nothing about pseudo insns. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26bpf: verifier (add ability to receive verification log)Alexei Starovoitov2-1/+236
add optional attributes for BPF_PROG_LOAD syscall: union bpf_attr { struct { ... __u32 log_level; /* verbosity level of eBPF verifier */ __u32 log_size; /* size of user buffer */ __aligned_u64 log_buf; /* user supplied 'char *buffer' */ }; }; when log_level > 0 the verifier will return its verification log in the user supplied buffer 'log_buf' which can be used by program author to analyze why verifier rejected given program. 'Understanding eBPF verifier messages' section of Documentation/networking/filter.txt provides several examples of these messages, like the program: BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), BPF_LD_MAP_FD(BPF_REG_1, 0), BPF_CALL_FUNC(BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0), BPF_EXIT_INSN(), will be rejected with the following multi-line message in log_buf: 0: (7a) *(u64 *)(r10 -8) = 0 1: (bf) r2 = r10 2: (07) r2 += -8 3: (b7) r1 = 0 4: (85) call 1 5: (15) if r0 == 0x0 goto pc+1 R0=map_ptr R10=fp 6: (7a) *(u64 *)(r0 +4) = 0 misaligned access off 4 size 8 The format of the output can change at any time as verifier evolves. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26bpf: verifier (add docs)Alexei Starovoitov3-2/+135
this patch adds all of eBPF verfier documentation and empty bpf_check() The end goal for the verifier is to statically check safety of the program. Verifier will catch: - loops - out of range jumps - unreachable instructions - invalid instructions - uninitialized register access - uninitialized stack access - misaligned stack access - out of range stack access - invalid calling convention More details in Documentation/networking/filter.txt Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>