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2017-07-11Merge branch 'stmmac-dma-resources-fixes'David S. Miller
Christophe JAILLET says: ==================== net: stmmac: Fixes and cleanups in 'alloc_dma_[rt]x_desc_resources()' These patchs are all related to 'alloc_dma_[rt]x_desc_resources()' functions. The 2 first fix an error path where some resources are leaking. I've separated them into 2 patches because the issues have been introduced by 2 deferent commits. The 3rd patch is just a clean-up. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11net: stmmac: Make 'alloc_dma_[rt]x_desc_resources()' look even closerChristophe Jaillet
'alloc_dma_[rt]x_desc_resources()' functions look very close. Remove a useless initialization and use the same label name for error handling path in order to get them even closer. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11net: stmmac: Fix error handling path in 'alloc_dma_tx_desc_resources()'Christophe Jaillet
If the first 'kmalloc_array' within the loop fails, we should free what as already been allocated, as done in all other error handling path. Fixes: ce736788e8a9 ("net: stmmac: adding multiple buffers for TX") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11net: stmmac: Fix error handling path in 'alloc_dma_rx_desc_resources()'Christophe Jaillet
If the first 'kmalloc_array' within the loop fails, we should free what as already been allocated, as done in all other error handling path. Fixes: 54139cf3bb33 ("net: stmmac: adding multiple buffers for rx") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11Merge tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-clientLinus Torvalds
Pull ceph updates from Ilya Dryomov: "The main item here is support for v12.y.z ("Luminous") clusters: RESEND_ON_SPLIT, RADOS_BACKOFF, OSDMAP_PG_UPMAP and CRUSH_CHOOSE_ARGS feature bits, and various other changes in the RADOS client protocol. On top of that we have a new fsc mount option to allow supplying fscache uniquifier (similar to NFS) and the usual pile of filesystem fixes from Zheng" * tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-client: (44 commits) libceph: advertise support for NEW_OSDOP_ENCODING and SERVER_LUMINOUS libceph: osd_state is 32 bits wide in luminous crush: remove an obsolete comment crush: crush_init_workspace starts with struct crush_work libceph, crush: per-pool crush_choose_arg_map for crush_do_rule() crush: implement weight and id overrides for straw2 libceph: apply_upmap() libceph: compute actual pgid in ceph_pg_to_up_acting_osds() libceph: pg_upmap[_items] infrastructure libceph: ceph_decode_skip_* helpers libceph: kill __{insert,lookup,remove}_pg_mapping() libceph: introduce and switch to decode_pg_mapping() libceph: don't pass pgid by value libceph: respect RADOS_BACKOFF backoffs libceph: make DEFINE_RB_* helpers more general libceph: avoid unnecessary pi lookups in calc_target() libceph: use target pi for calc_target() calculations libceph: always populate t->target_{oid,oloc} in calc_target() libceph: make sure need_resend targets reflect latest map libceph: delete from need_resend_linger before check_linger_pool_dne() ...
2017-07-11cisco: enic: Fic an error handling path in 'vnic_dev_init_devcmd2()'Christophe Jaillet
if 'ioread32()' returns 0xFFFFFFF, we have to go through the error handling path as done everywhere else in this function. Move the 'err_free_wq' label to better match its name and its location and add a new label 'err_disable_wq'. Update the code accordingly. Fixes: 373fb0873d43 ("enic: add devcmd2") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11Merge branch 'bnxt_en-Bug-fixes'David S. Miller
Michael Chan says: ==================== bnxt_en: Bug fixes. 3 bug fixes in this series. Fix a crash in bnxt_get_stats64() that can happen if the device is closing and freeing the statistics block at the same time. The 2nd one fixes ethtool -L failing when changing from combined to non-combined mode or vice versa. The last one fixes SRIOV failure on big-endian systems because we were setting a bitmap wrong in a firmware message. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11bnxt_en: Fix SRIOV on big-endian architecture.Michael Chan
The PF driver sets up a list of firmware commands from the VF driver that needs to be forwarded to the PF for approval. This list is a 256-bit bitmap. The code that sets up the bitmap falls apart on big-endian architecture. __set_bit() does not work because it operates on long types whereas the firmware interface is defined in u32 types, causing bits in the wrong 32-bit word to be set. Fix it by setting the proper bits on an array of u32. Fixes: de68f5de5651 ("bnxt_en: Fix bitmap declaration to work on 32-bit arches.") Reported-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11bnxt_en: Fix bug in ethtool -L.Michael Chan
When changing channels from combined to rx/tx or vice versa, the code uses the wrong "sh" parameter to determine if we are reserving rings for shared or non-shared mode. It should be using the ethtool requested "sh" parameter instead of the current "sh" parameter. Fix it by passing the "sh" parameter to bnxt_reserve_rings(). For ethtool, we will pass in the requested "sh" parameter. Fixes: 391be5c27364 ("bnxt_en: Implement new scheme to reserve tx rings.") Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11bnxt_en: Fix race conditions in .ndo_get_stats64().Michael Chan
.ndo_get_stats64() may not be protected by RTNL and can race with .ndo_stop() or other ethtool operations that can free the statistics memory. Fix it by setting a new flag BNXT_STATE_READ_STATS and then proceeding to read statistics memory only if the state is OPEN. The close path that frees the memory clears the OPEN state and then waits for the BNXT_STATE_READ_STATS to clear before proceeding to free the statistics memory. Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.") Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11Merge git://www.linux-watchdog.org/linux-watchdogLinus Torvalds
Pull watchdog updates from Wim Van Sebroeck: - Add Renesas RZ/A WDT Watchdog driver - STM32 Independent WatchDoG (IWDG) support - UniPhier watchdog support - Add F71868 support - Add support for NCT6793D and NCT6795D - dw_wdt: add reset lines support - core: add option to avoid early handling of watchdog - core: introduce watchdog_worker_should_ping helper - Cleanups and improvements for sama5d4, intel-mid_wdt, s3c2410_wdt, orion_wdt, gpio_wdt, it87_wdt, meson_wdt, davinci_wdt, bcm47xx_wdt, zx2967_wdt, cadence_wdt * git://www.linux-watchdog.org/linux-watchdog: (32 commits) watchdog: introduce watchdog_worker_should_ping helper watchdog: uniphier: add UniPhier watchdog driver dt-bindings: watchdog: add description for UniPhier WDT controller watchdog: cadence_wdt: make of_device_ids const. watchdog: zx2967: constify zx2967_wdt_ops. watchdog: bcm47xx_wdt: constify bcm47xx_wdt_hard_ops and bcm47xx_wdt_soft_ops watchdog: davinci: Add missing clk_disable_unprepare(). watchdog: davinci: Handle return value of clk_prepare_enable watchdog: meson: Handle return value of clk_prepare_enable watchdog: it87: Add support for various Super-IO chips watchdog: it87: Use infrastructure to stop watchdog on reboot watchdog: it87: Drop support for resetting watchdog though CIR and Game port watchdog: it87: Convert to use watchdog core infrastructure watchdog: it87: Drop FSF mailing address watchdog: dw_wdt: get reset lines from dt watchdog: bindings: dw_wdt: add reset lines watchdog: w83627hf: Add support for NCT6793D and NCT6795D watchdog: core: add option to avoid early handling of watchdog watchdog: f71808e_wdt: Add F71868 support watchdog: Add STM32 IWDG driver ...
2017-07-11Merge tag 'chrome-platform-for-linus-4.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform Pull chrome platform updates from Benson Leung: "Changes in this pull request are around catching up cros_ec with the internal chromeos-kernel versions of cros_ec, cros_ec_lpc, and cros_ec_lightbar. Also, switching maintainership from olof to bleung" * tag 'chrome-platform-for-linus-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform: platform/chrome : Add myself as Maintainer platform/chrome: cros_ec_lightbar - hide unused PM functions cros_ec: Don't signal wake event for non-wake host events cros_ec: Fix deadlock when EC is not responsive at probe cros_ec: Don't return error when checking command version platform/chrome: cros_ec_lightbar - Avoid I2C xfer to EC during suspend platform/chrome: cros_ec_lightbar - Add userspace lightbar control bit to EC platform/chrome: cros_ec_lightbar - Control of suspend/resume lightbar sequence platform/chrome: cros_ec_lightbar - Add lightbar program feature to sysfs platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI platform/chrome: cros_ec_lpc: Add power management ops platform/chrome: cros_ec_lpc: Add support for GOOG004 ACPI device platform/chrome: cros_ec_lpc: Add support for mec1322 EC platform/chrome: cros_ec_lpc: Add R/W helpers to LPC protocol variants mfd: cros_ec: Add support for dumping panic information cros_ec_debugfs: Pass proper struct sizes to cros_ec_cmd_xfer() mfd: cros_ec: add debugfs, console log file mfd: cros_ec: Add EC console read structures definitions mfd: cros_ec: Add helper for event notifier.
2017-07-11Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu Pull x86nommu update from Greg Ungerer: "Only a single change, to remove old Kconfig options from defconfigs" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: m68k: defconfig: Cleanup from old Kconfig options
2017-07-11platform/x86: toshiba_acpi: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 26360 1072 24 27456 6b40 drivers/platform/x86/toshiba_acpi.o File size After adding 'const': text data bss dec hex filename 26424 1008 24 27456 6b40 drivers/platform/x86/toshiba_acpi.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: asus-wmi: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 13140 840 1 13981 369d drivers/platform/x86/asus-wmi.o File size After adding 'const': text data bss dec hex filename 13268 712 1 13981 368d drivers/platform/x86/asus-wmi.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: panasonic-laptop: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 2505 600 4 3109 c25 drivers/platform/x86/panasonic-laptop.o File size After adding 'const': text data bss dec hex filename 2569 536 4 3109 c25 drivers/platform/x86/panasonic-laptop.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: alienware-wmi: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 6932 1016 48 7996 1f3c drivers/platform/x86/alienware-wmi.o File size After adding 'const': text data bss dec hex filename 7060 888 48 7996 1f64 drivers/platform/x86/alienware-wmi.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: samsung-laptop: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 8710 5452 23 14185 3769 drivers/platform/x86/samsung-laptop.o File size After adding 'const': text data bss dec hex filename 8774 5388 23 14185 3769 drivers/platform/x86/samsung-laptop.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: compal-laptop: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 6781 6144 34 12959 329f drivers/platform/x86/compal-laptop.o File size After adding 'const': text data bss dec hex filename 6845 6080 34 12959 329f drivers/platform/x86/compal-laptop.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: fujitsu-laptop: constify attribute_group structures.Arvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 7474 1205 24 8703 21ff drivers/platform/x86/fujitsu-laptop.o File size After adding 'const': text data bss dec hex filename 7538 1141 24 8703 21ff drivers/platform/x86/fujitsu-laptop.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Reviewed-by: Jonathan Woithe <jwoithe@just42.net> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11platform/x86: peaq-wmi: Fix peaq_ignore_events_counter handling off by 1Hans de Goede
If peaq_ignore_events_counter gets set to 1 we should skip polling 1 time, rather then ignoring it. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-07-11proc: Fix proc_sys_prune_dcache to hold a sb referenceEric W. Biederman
Andrei Vagin writes: FYI: This bug has been reproduced on 4.11.7 > BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo} still in use (1) [unmount of proc proc] > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 13588 at fs/dcache.c:1445 umount_check+0x6e/0x80 > CPU: 1 PID: 13588 Comm: kworker/1:1 Not tainted 4.11.7-200.fc25.x86_64 #1 > Hardware name: CompuLab sbc-flt1/fitlet, BIOS SBCFLT_0.08.04 06/27/2015 > Workqueue: events proc_cleanup_work > Call Trace: > dump_stack+0x63/0x86 > __warn+0xcb/0xf0 > warn_slowpath_null+0x1d/0x20 > umount_check+0x6e/0x80 > d_walk+0xc6/0x270 > ? dentry_free+0x80/0x80 > do_one_tree+0x26/0x40 > shrink_dcache_for_umount+0x2d/0x90 > generic_shutdown_super+0x1f/0xf0 > kill_anon_super+0x12/0x20 > proc_kill_sb+0x40/0x50 > deactivate_locked_super+0x43/0x70 > deactivate_super+0x5a/0x60 > cleanup_mnt+0x3f/0x90 > mntput_no_expire+0x13b/0x190 > kern_unmount+0x3e/0x50 > pid_ns_release_proc+0x15/0x20 > proc_cleanup_work+0x15/0x20 > process_one_work+0x197/0x450 > worker_thread+0x4e/0x4a0 > kthread+0x109/0x140 > ? process_one_work+0x450/0x450 > ? kthread_park+0x90/0x90 > ret_from_fork+0x2c/0x40 > ---[ end trace e1c109611e5d0b41 ]--- > VFS: Busy inodes after unmount of proc. Self-destruct in 5 seconds. Have a nice day... > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: _raw_spin_lock+0xc/0x30 > PGD 0 Fix this by taking a reference to the super block in proc_sys_prune_dcache. The superblock reference is the core of the fix however the sysctl_inodes list is converted to a hlist so that hlist_del_init_rcu may be used. This allows proc_sys_prune_dache to remove inodes the sysctl_inodes list, while not causing problems for proc_sys_evict_inode when if it later choses to remove the inode from the sysctl_inodes list. Removing inodes from the sysctl_inodes list allows proc_sys_prune_dcache to have a progress guarantee, while still being able to drop all locks. The fact that head->unregistering is set in start_unregistering ensures that no more inodes will be added to the the sysctl_inodes list. Previously the code did a dance where it delayed calling iput until the next entry in the list was being considered to ensure the inode remained on the sysctl_inodes list until the next entry was walked to. The structure of the loop in this patch does not need that so is much easier to understand and maintain. Cc: stable@vger.kernel.org Reported-by: Andrei Vagin <avagin@gmail.com> Tested-by: Andrei Vagin <avagin@openvz.org> Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.") Fixes: d6cffbbe9a7e ("proc/sysctl: prune stale dentries during unregistering") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-07-11Merge tag 'gvt-fixes-2017-07-11' of https://github.com/01org/gvt-linux into ↵Jani Nikula
drm-intel-next-fixes gvt-fixes-2017-07-11 - Revert "drm/i915/gvt: Fix possible recursive locking issue" (Chuanxiao), which is incomplete fix and it's actually VFIO issue, so revert. - remove unneeded scheduler mutex for performance fix (Weinan) - other misc error handling fix and cmd address audit Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170711055333.jhrmvx6ilvg2qlnn@zhen-hp.sh.intel.com
2017-07-11drm/i915: Make DP-MST connector info workMaarten Lankhorst
Commit 9a148a96fc3a ("drm/i915/debugfs: add dp mst info") adds support for DP-MST to intel_connector_info, but forgot to remove the early return for DP-MST. Remove it, and print out MST connectors directly. Fixes: 9a148a96fc3a ("drm/i915/debugfs: add dp mst info") Cc: <stable@vger.kernel.org> # v4.11+ Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Libin Yang <libin.yang@intel.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170626083349.24389-1-maarten.lankhorst@linux.intel.com Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> (cherry picked from commit 77d1f615c78a73a04254fa2bff07ee9fa27145d9) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2017-07-11drm/i915/gvt: Use fence error from GVT request for workload statusChuanxiao Dong
The req->fence.error will be set if this request caused GPU hang so we can use this value to workload->status to indicate whether this GVT request caused any problem. If it caused GPU hang, we shouldn't trigger any context switch back to the guest. v2: - only take -EIO from fence->error. (Zhenyu) Fixes: 8f1117abb408 (drm/i915/gvt: handle workload lifecycle properly) Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2017-07-11drm/i915/gvt: remove scheduler_mutex in per-engine workload_threadWeinan Li
For the vGPU workloads, now GVT-g use per vGPU scheduler, the per-ring work_thread only pick workload belongs to the current vGPU. And with time slice based scheduler, it waits all the engines become idle before do vGPU switch. So we can run free dispatch in per-ring work_thread, different ring running in different 'vGPU' won't happen. For the workloads between vGPU and Host, this scheduler_mutex can't block host to dispatch workload into other ring engines. Here remove this mutex since it impacts the performance when applications use more than 1 ring engines in 1 vgpu. ring0 running in vGPU1, ring1 running in Host. Will happen. ring0 running in vGPU1, ring1 running in vGPU2. Won't happen. Signed-off-by: Weinan Li <weinan.z.li@intel.com> Signed-off-by: Ping Gao <ping.a.gao@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2017-07-11drm/i915/gvt: Revert "drm/i915/gvt: Fix possible recursive locking issue"Chuanxiao Dong
This reverts commit 62d02fd1f807bf5a259a242c483c9fb98a242630. The rwsem recursive trace should not be fixed from kvmgt side by using a workqueue and it is an issue should be fixed in VFIO. So this one should be reverted. Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2017-07-11drm/i915/gvt: Audit the command buffer addressPing Gao
The command buffer address in context like ring buffer base address and wa_ctx address need to be audit to make sure they are in the valid GGTT range. Signed-off-by: Ping Gao <ping.a.gao@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2017-07-11drm/i915/gvt: Fix a memory leak in intel_gvt_init_gtt()Zhou, Wenjia
It will causes memory leak, if the function setup_spt_oos() fail, in the function intel_gvt_init_gtt(), which allocated by get_zeroed_page() and mapped by dma_map_page(). Unmap and free the page, after STP oos initialize fail, it will fix this issue. Signed-off-by: Zhou, Wenjia <zhiyuan_zhu@htc.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2017-07-10Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - most of the rest of MM - KASAN updates - lib/ updates - checkpatch updates - some binfmt_elf changes - various misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (115 commits) kernel/exit.c: avoid undefined behaviour when calling wait4() kernel/signal.c: avoid undefined behaviour in kill_something_info binfmt_elf: safely increment argv pointers s390: reduce ELF_ET_DYN_BASE powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB arm64: move ELF_ET_DYN_BASE to 4GB / 4MB arm: move ELF_ET_DYN_BASE to 4MB binfmt_elf: use ELF_ET_DYN_BASE only for PIE fs, epoll: short circuit fetching events if thread has been killed checkpatch: improve multi-line alignment test checkpatch: improve macro reuse test checkpatch: change format of --color argument to --color[=WHEN] checkpatch: silence perl 5.26.0 unescaped left brace warnings checkpatch: improve tests for multiple line function definitions checkpatch: remove false warning for commit reference checkpatch: fix stepping through statements with $stat and ctx_statement_block checkpatch: [HLP]LIST_HEAD is also declaration checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t checkpatch: improve the unnecessary OOM message test lib/bsearch.c: micro-optimize pivot position calculation ...
2017-07-10kernel/exit.c: avoid undefined behaviour when calling wait4()zhongjiang
wait4(-2147483648, 0x20, 0, 0xdd0000) triggers: UBSAN: Undefined behaviour in kernel/exit.c:1651:9 The related calltrace is as follows: negation of -2147483648 cannot be represented in type 'int': CPU: 9 PID: 16482 Comm: zj Tainted: G B ---- ------- 3.10.0-327.53.58.71.x86_64+ #66 Hardware name: Huawei Technologies Co., Ltd. Tecal RH2285 /BC11BTSA , BIOS CTSAV036 04/27/2011 Call Trace: dump_stack+0x19/0x1b ubsan_epilogue+0xd/0x50 __ubsan_handle_negate_overflow+0x109/0x14e SyS_wait4+0x1cb/0x1e0 system_call_fastpath+0x16/0x1b Exclude the overflow to avoid the UBSAN warning. Link: http://lkml.kernel.org/r/1497264618-20212-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhongjiang <zhongjiang@huawei.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10kernel/signal.c: avoid undefined behaviour in kill_something_infozhongjiang
When running kill(72057458746458112, 0) in userspace I hit the following issue. UBSAN: Undefined behaviour in kernel/signal.c:1462:11 negation of -2147483648 cannot be represented in type 'int': CPU: 226 PID: 9849 Comm: test Tainted: G B ---- ------- 3.10.0-327.53.58.70.x86_64_ubsan+ #116 Hardware name: Huawei Technologies Co., Ltd. RH8100 V3/BC61PBIA, BIOS BLHSV028 11/11/2014 Call Trace: dump_stack+0x19/0x1b ubsan_epilogue+0xd/0x50 __ubsan_handle_negate_overflow+0x109/0x14e SYSC_kill+0x43e/0x4d0 SyS_kill+0xe/0x10 system_call_fastpath+0x16/0x1b Add code to avoid the UBSAN detection. [akpm@linux-foundation.org: tweak comment] Link: http://lkml.kernel.org/r/1496670008-59084-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhongjiang <zhongjiang@huawei.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10binfmt_elf: safely increment argv pointersKees Cook
When building the argv/envp pointers, the envp is needlessly pre-incremented instead of just continuing after the argv pointers are finished. In some (likely impossible) race where the strings could be changed from userspace between copy_strings() and here, it might be possible to confuse the envp position. Instead, just use sp like everything else. Link: http://lkml.kernel.org/r/20170622173838.GA43308@beast Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Rik van Riel <riel@redhat.com> Cc: Daniel Micay <danielmicay@gmail.com> Cc: Qualys Security Advisory <qsa@qualys.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10s390: reduce ELF_ET_DYN_BASEKees Cook
Now that explicitly executed loaders are loaded in the mmap region, we have more freedom to decide where we position PIE binaries in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. On 32-bit use 4MB, which is the traditional x86 minimum load location, likely to avoid historically requiring a 4MB page table entry when only a portion of the first 4MB would be used (since the NULL address is avoided). For s390 the position could be 0x10000, but that is needlessly close to the NULL address. Link: http://lkml.kernel.org/r/1498154792-49952-5-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Pratyush Anand <panand@redhat.com> 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>
2017-07-10powerpc: move ELF_ET_DYN_BASE to 4GB / 4MBKees Cook
Now that explicitly executed loaders are loaded in the mmap region, we have more freedom to decide where we position PIE binaries in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. On 32-bit use 4MB, which is the traditional x86 minimum load location, likely to avoid historically requiring a 4MB page table entry when only a portion of the first 4MB would be used (since the NULL address is avoided). Link: http://lkml.kernel.org/r/1498154792-49952-4-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Pratyush Anand <panand@redhat.com> 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>
2017-07-10arm64: move ELF_ET_DYN_BASE to 4GB / 4MBKees Cook
Now that explicitly executed loaders are loaded in the mmap region, we have more freedom to decide where we position PIE binaries in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. On 32-bit use 4MB, to match ARM. This could be 0x8000, the standard ET_EXEC load address, but that is needlessly close to the NULL address, and anyone running arm compat PIE will have an MMU, so the tight mapping is not needed. Link: http://lkml.kernel.org/r/1498251600-132458-4-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10arm: move ELF_ET_DYN_BASE to 4MBKees Cook
Now that explicitly executed loaders are loaded in the mmap region, we have more freedom to decide where we position PIE binaries in the address space to avoid possible collisions with mmap or stack regions. 4MB is chosen here mainly to have parity with x86, where this is the traditional minimum load location, likely to avoid historically requiring a 4MB page table entry when only a portion of the first 4MB would be used (since the NULL address is avoided). For ARM the position could be 0x8000, the standard ET_EXEC load address, but that is needlessly close to the NULL address, and anyone running PIE on 32-bit ARM will have an MMU, so the tight mapping is not needed. Link: http://lkml.kernel.org/r/1498154792-49952-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Pratyush Anand <panand@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Daniel Micay <danielmicay@gmail.com> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Qualys Security Advisory <qsa@qualys.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10binfmt_elf: use ELF_ET_DYN_BASE only for PIEKees Cook
The ELF_ET_DYN_BASE position was originally intended to keep loaders away from ET_EXEC binaries. (For example, running "/lib/ld-linux.so.2 /bin/cat" might cause the subsequent load of /bin/cat into where the loader had been loaded.) With the advent of PIE (ET_DYN binaries with an INTERP Program Header), ELF_ET_DYN_BASE continued to be used since the kernel was only looking at ET_DYN. However, since ELF_ET_DYN_BASE is traditionally set at the top 1/3rd of the TASK_SIZE, a substantial portion of the address space is unused. For 32-bit tasks when RLIMIT_STACK is set to RLIM_INFINITY, programs are loaded above the mmap region. This means they can be made to collide (CVE-2017-1000370) or nearly collide (CVE-2017-1000371) with pathological stack regions. Lowering ELF_ET_DYN_BASE solves both by moving programs below the mmap region in all cases, and will now additionally avoid programs falling back to the mmap region by enforcing MAP_FIXED for program loads (i.e. if it would have collided with the stack, now it will fail to load instead of falling back to the mmap region). To allow for a lower ELF_ET_DYN_BASE, loaders (ET_DYN without INTERP) are loaded into the mmap region, leaving space available for either an ET_EXEC binary with a fixed location or PIE being loaded into mmap by the loader. Only PIE programs are loaded offset from ELF_ET_DYN_BASE, which means architectures can now safely lower their values without risk of loaders colliding with their subsequently loaded programs. For 64-bit, ELF_ET_DYN_BASE is best set to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. Thanks to PaX Team, Daniel Micay, and Rik van Riel for inspiration and suggestions on how to implement this solution. Fixes: d1fd836dcf00 ("mm: split ET_DYN ASLR from mmap ASLR") Link: http://lkml.kernel.org/r/20170621173201.GA114489@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Daniel Micay <danielmicay@gmail.com> Cc: Qualys Security Advisory <qsa@qualys.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Pratyush Anand <panand@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10fs, epoll: short circuit fetching events if thread has been killedDavid Rientjes
We've encountered zombies that are waiting for a thread to exit that are looping in ep_poll() almost endlessly although there is a pending SIGKILL as a result of a group exit. This happens because we always find ep_events_available() and fetch more events and never are able to check for signal_pending() that would break from the loop and return -EINTR. Special case fatal signals and break immediately to guarantee that we loop to fetch more events and delay making a timely exit. It would also be possible to simply move the check for signal_pending() higher than checking for ep_events_available(), but there have been no reports of delayed signal handling other than SIGKILL preventing zombies from exiting that would be fixed by this. It fixes an issue for us where we have witnessed zombies sticking around for at least O(minutes), but considering the code has been like this forever and nobody else has complained that I have found, I would simply queue it up for 4.12. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705031722350.76784@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jan Kara <jack@suse.cz> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: improve multi-line alignment testJoe Perches
The current test fails to warn about improper alignment with code like foo->bar = func(arg1, arg2); because foo->bar is not a single identifier. Convert the $Ident to $Lval which allows for multiple dereferences. Link: http://lkml.kernel.org/r/01c35b9b6a12a415e57746d45d589bfaad39952a.1498841563.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: improve macro reuse testJoe Perches
checkpatch reports a false positive when using token pasting argument multiple times in a macro. Fix it. Miscellanea: o Make the $tmp variable name used in the macro argument tests a bit more descriptive Link: http://lkml.kernel.org/r/cf434ae7602838388c7cb49d42bca93ab88527e7.1498483044.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: change format of --color argument to --color[=WHEN]John Brooks
The boolean --color argument did not offer the ability to force colourized output even if stdout is not a terminal. Change the format of the argument to the familiar --color[=WHEN] construct as seen in common Linux utilities such as git, ls and dmesg, which allows the user to specify whether to colourize output "always", "never", or "auto" when the output is a terminal. The default is "auto". The old command-line uses of --color and --no-color are unchanged. Link: http://lkml.kernel.org/r/efe43bdbad400f39ba691ae663044462493b0773.1496799721.git.joe@perches.com Signed-off-by: John Brooks <john@fastquake.com> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: silence perl 5.26.0 unescaped left brace warningsCyril Bur
As of perl 5, version 26, subversion 0 (v5.26.0) some new warnings have occurred when running checkpatch. Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){ <-- HERE \s*/ at scripts/checkpatch.pl line 3544. Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){ <-- HERE \s*/ at scripts/checkpatch.pl line 3885. Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <-- HERE in m/^(\+.*(?:do|\))){ <-- HERE / at scripts/checkpatch.pl line 4374. It seems perfectly reasonable to do as the warning suggests and simply escape the left brace in these three locations. Link: http://lkml.kernel.org/r/20170607060135.17384-1-cyrilbur@gmail.com Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Acked-by: Joe Perches <joe@perches.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: improve tests for multiple line function definitionsJoe Perches
Add a block that identifies multiple line function definitions. Save the function name into $context_function to improve the embedded function name test. Look for misplaced open brace on the function definition. Emit an OPEN_BRACE error when the function definition is similar to void foo(int arg1, int arg2) { Miscellanea: o Remove the $realfile test in function declaration w/o named arguments test o Comment the function declaration w/o named arguments test Link: http://lkml.kernel.org/r/de620ed6ebab75fdfa323741ada2134a0f545892.1496835238.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Tested-by: David Kershner <david.kershner@unisys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: remove false warning for commit referenceHeinrich Schuchardt
Checkpatch warns of an incorrect commit reference style for any hexadecimal number of 12 digits and more. Numbers of 12 digits are not necessarily commit ids. For an example provoking the problem see https://patchwork.kernel.org/patch/9170897/ Checkpatch should only warn if the number refers to an existing commit. Link: http://lkml.kernel.org/r/20170607184008.5869-1-xypron.glpk@gmx.de Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: fix stepping through statements with $stat and ctx_statement_blockJoe Perches
Fix the off-by-one in the suppression of lines in a statement block. This means that for multiple line statements like foo(bar, baz, qux); $stat has been inspected first correctly for the entire statement, and subsequently incorrectly just for qux); This fix will help make tracking appropriate indentation a little easier. Link: http://lkml.kernel.org/r/71b25979c90412133c717084036c9851cd2b7bcb.1496862585.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: [HLP]LIST_HEAD is also declarationSteffen Maier
Fixes the following false warning among others for LLIST_HEAD and PLIST_HEAD: WARNING: Missing a blank line after declarations #71: FILE: drivers/s390/scsi/zfcp_fsf.c:422: + struct hlist_node *tmp; + HLIST_HEAD(remove_queue); Link: http://lkml.kernel.org/r/20170614133512.89425-1-maier@linux.vnet.ibm.com Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\tJoe Perches
For consistency, MAINTAINERS entries should be an upper case letter, then a colon, then a tab, then the value. Warn when an entry doesn't have this form. --fix it too. Link: http://lkml.kernel.org/r/9aaaf03ec10adf3888b5e98dd2176b7fe9b5fad8.1496343345.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10checkpatch: improve the unnecessary OOM message testJoe Perches
Use the context around a patch to avoid missing some candidates. Link: http://lkml.kernel.org/r/865e874fbae5decc331a849bd8d71c325db6bc80.1496343345.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10lib/bsearch.c: micro-optimize pivot position calculationSergey Senozhatsky
There is a slightly faster way (in terms of the number of instructions being used) to calculate the position of a middle element, preserving integer overflow safeness. ./scripts/bloat-o-meter lib/bsearch.o.old lib/bsearch.o.new add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-24 (-24) function old new delta bsearch 122 98 -24 TEST INT array of size 100001, elements [0..100000]. gcc 7.1, Os, x86_64. a) bsearch() of existing key "100001 - 2": BASE ==== $ perf stat ./a.out Performance counter stats for './a.out': 619.445196 task-clock:u (msec) # 0.999 CPUs utilized 0 context-switches:u # 0.000 K/sec 0 cpu-migrations:u # 0.000 K/sec 133 page-faults:u # 0.215 K/sec 1,949,517,279 cycles:u # 3.147 GHz (83.06%) 181,017,938 stalled-cycles-frontend:u # 9.29% frontend cycles idle (83.05%) 82,959,265 stalled-cycles-backend:u # 4.26% backend cycles idle (67.02%) 4,355,706,383 instructions:u # 2.23 insn per cycle # 0.04 stalled cycles per insn (83.54%) 1,051,539,242 branches:u # 1697.550 M/sec (83.54%) 15,263,381 branch-misses:u # 1.45% of all branches (83.43%) 0.620082548 seconds time elapsed PATCHED ======= $ perf stat ./a.out Performance counter stats for './a.out': 475.097316 task-clock:u (msec) # 0.999 CPUs utilized 0 context-switches:u # 0.000 K/sec 0 cpu-migrations:u # 0.000 K/sec 135 page-faults:u # 0.284 K/sec 1,487,467,717 cycles:u # 3.131 GHz (82.95%) 186,537,162 stalled-cycles-frontend:u # 12.54% frontend cycles idle (82.93%) 28,797,869 stalled-cycles-backend:u # 1.94% backend cycles idle (67.10%) 3,807,564,203 instructions:u # 2.56 insn per cycle # 0.05 stalled cycles per insn (83.57%) 1,049,344,291 branches:u # 2208.693 M/sec (83.60%) 5,485 branch-misses:u # 0.00% of all branches (83.58%) 0.475760235 seconds time elapsed b) bsearch() of un-existing key "100001 + 2": BASE ==== $ perf stat ./a.out Performance counter stats for './a.out': 499.244480 task-clock:u (msec) # 0.999 CPUs utilized 0 context-switches:u # 0.000 K/sec 0 cpu-migrations:u # 0.000 K/sec 132 page-faults:u # 0.264 K/sec 1,571,194,855 cycles:u # 3.147 GHz (83.18%) 13,450,980 stalled-cycles-frontend:u # 0.86% frontend cycles idle (83.18%) 21,256,072 stalled-cycles-backend:u # 1.35% backend cycles idle (66.78%) 4,171,197,909 instructions:u # 2.65 insn per cycle # 0.01 stalled cycles per insn (83.68%) 1,009,175,281 branches:u # 2021.405 M/sec (83.79%) 3,122 branch-misses:u # 0.00% of all branches (83.37%) 0.499871144 seconds time elapsed PATCHED ======= $ perf stat ./a.out Performance counter stats for './a.out': 399.023499 task-clock:u (msec) # 0.998 CPUs utilized 0 context-switches:u # 0.000 K/sec 0 cpu-migrations:u # 0.000 K/sec 134 page-faults:u # 0.336 K/sec 1,245,793,991 cycles:u # 3.122 GHz (83.39%) 11,529,273 stalled-cycles-frontend:u # 0.93% frontend cycles idle (83.46%) 12,116,311 stalled-cycles-backend:u # 0.97% backend cycles idle (66.92%) 3,679,710,005 instructions:u # 2.95 insn per cycle # 0.00 stalled cycles per insn (83.47%) 1,009,792,625 branches:u # 2530.660 M/sec (83.46%) 2,590 branch-misses:u # 0.00% of all branches (83.12%) 0.399733539 seconds time elapsed Link: http://lkml.kernel.org/r/20170607150457.5905-1-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>