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* Merge 4.4.181 into android-4.4Greg Kroah-Hartman2019-06-11
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| Changes in 4.4.181 x86/speculation/mds: Revert CPU buffer clear on double fault exit x86/speculation/mds: Improve CPU buffer clear documentation ARM: exynos: Fix a leaked reference by adding missing of_node_put crypto: vmx - fix copy-paste error in CTR mode crypto: crct10dif-generic - fix use via crypto_shash_digest() crypto: x86/crct10dif-pcl - fix use via crypto_shash_digest() ALSA: usb-audio: Fix a memory leak bug ALSA: hda/hdmi - Consider eld_valid when reporting jack event ALSA: hda/realtek - EAPD turn on later ASoC: max98090: Fix restore of DAPM Muxes ASoC: RT5677-SPI: Disable 16Bit SPI Transfers mm/mincore.c: make mincore() more conservative ocfs2: fix ocfs2 read inode data panic in ocfs2_iget mfd: da9063: Fix OTP control register names to match datasheets for DA9063/63L tty/vt: fix write/write race in ioctl(KDSKBSENT) handler ext4: actually request zeroing of inode table after grow ext4: fix ext4_show_options for file systems w/o journal Btrfs: do not start a transaction at iterate_extent_inodes() bcache: fix a race between cache register and cacheset unregister bcache: never set KEY_PTRS of journal key to 0 in journal_reclaim() ipmi:ssif: compare block number correctly for multi-part return messages crypto: gcm - Fix error return code in crypto_gcm_create_common() crypto: gcm - fix incompatibility between "gcm" and "gcm_base" crypto: chacha20poly1305 - set cra_name correctly crypto: salsa20 - don't access already-freed walk.iv crypto: arm/aes-neonbs - don't access already-freed walk.iv writeback: synchronize sync(2) against cgroup writeback membership switches fs/writeback.c: use rcu_barrier() to wait for inflight wb switches going into workqueue when umount ext4: zero out the unused memory region in the extent tree block ALSA: hda/realtek - Fix for Lenovo B50-70 inverted internal microphone bug KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes net: avoid weird emergency message net/mlx4_core: Change the error print to info print ppp: deflate: Fix possible crash in deflate_init tipc: switch order of device registration to fix a crash tipc: fix modprobe tipc failed after switch order of device registration stm class: Fix channel free in stm output free path md: add mddev->pers to avoid potential NULL pointer dereference intel_th: msu: Fix single mode with IOMMU of: fix clang -Wunsequenced for be32_to_cpu() cifs: fix strcat buffer overflow and reduce raciness in smb21_set_oplock_level() media: ov6650: Fix sensor possibly not detected on probe NFS4: Fix v4.0 client state corruption when mount clk: tegra: Fix PLLM programming on Tegra124+ when PMC overrides divider fuse: fix writepages on 32bit fuse: honor RLIMIT_FSIZE in fuse_file_fallocate iommu/tegra-smmu: Fix invalid ASID bits on Tegra30/114 ceph: flush dirty inodes before proceeding with remount tracing: Fix partial reading of trace event's id file memory: tegra: Fix integer overflow on tick value calculation perf intel-pt: Fix instructions sampling rate perf intel-pt: Fix improved sample timestamp perf intel-pt: Fix sample timestamp wrt non-taken branches fbdev: sm712fb: fix brightness control on reboot, don't set SR30 fbdev: sm712fb: fix VRAM detection, don't set SR70/71/74/75 fbdev: sm712fb: fix white screen of death on reboot, don't set CR3B-CR3F fbdev: sm712fb: fix boot screen glitch when sm712fb replaces VGA fbdev: sm712fb: fix crashes during framebuffer writes by correctly mapping VRAM fbdev: sm712fb: fix support for 1024x768-16 mode fbdev: sm712fb: use 1024x768 by default on non-MIPS, fix garbled display fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting PCI: Mark Atheros AR9462 to avoid bus reset dm delay: fix a crash when invalid device is specified xfrm: policy: Fix out-of-bound array accesses in __xfrm_policy_unlink xfrm6_tunnel: Fix potential panic when unloading xfrm6_tunnel module vti4: ipip tunnel deregistration fixes. xfrm4: Fix uninitialized memory read in _decode_session4 KVM: arm/arm64: Ensure vcpu target is unset on reset failure power: supply: sysfs: prevent endless uevent loop with CONFIG_POWER_SUPPLY_DEBUG ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour perf bench numa: Add define for RUSAGE_THREAD if not present Revert "Don't jump to compute_result state from check_result state" md/raid: raid5 preserve the writeback action after the parity check btrfs: Honour FITRIM range constraints during free space trim fbdev: sm712fb: fix memory frequency by avoiding a switch/case fallthrough ext4: do not delete unlinked inode from orphan list on failed truncate KVM: x86: fix return value for reserved EFER bio: fix improper use of smp_mb__before_atomic() Revert "scsi: sd: Keep disk read-only when re-reading partition" crypto: vmx - CTR: always increment IV as quadword gfs2: Fix sign extension bug in gfs2_update_stats Btrfs: fix race between ranged fsync and writeback of adjacent ranges btrfs: sysfs: don't leak memory when failing add fsid fbdev: fix divide error in fb_var_to_videomode hugetlb: use same fault hash key for shared and private mappings fbdev: fix WARNING in __alloc_pages_nodemask bug media: cpia2: Fix use-after-free in cpia2_exit media: vivid: use vfree() instead of kfree() for dev->bitmap_cap ssb: Fix possible NULL pointer dereference in ssb_host_pcmcia_exit at76c50x-usb: Don't register led_trigger if usb_register_driver failed perf tools: No need to include bitops.h in util.h tools include: Adopt linux/bits.h gfs2: Fix lru_count going negative cxgb4: Fix error path in cxgb4_init_module mmc: core: Verify SD bus width powerpc/boot: Fix missing check of lseek() return value ASoC: imx: fix fiq dependencies spi: pxa2xx: fix SCR (divisor) calculation brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() rtc: 88pm860x: prevent use-after-free on device remove w1: fix the resume command API dmaengine: pl330: _stop: clear interrupt status mac80211/cfg80211: update bss channel on channel switch ASoC: fsl_sai: Update is_slave_mode with correct value mwifiex: prevent an array overflow net: cw1200: fix a NULL pointer dereference bcache: return error immediately in bch_journal_replay() bcache: fix failure in journal relplay bcache: add failure check to run_cache_set() for journal replay bcache: avoid clang -Wunintialized warning x86/build: Move _etext to actual end of .text smpboot: Place the __percpu annotation correctly x86/mm: Remove in_nmi() warning from 64-bit implementation of vmalloc_fault() mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions HID: logitech-hidpp: use RAP instead of FAP to get the protocol version pinctrl: pistachio: fix leaked of_node references dmaengine: at_xdmac: remove BUG_ON macro in tasklet media: coda: clear error return value before picture run media: ov6650: Move v4l2_clk_get() to ov6650_video_probe() helper media: au0828: stop video streaming only when last user stops media: ov2659: make S_FMT succeed even if requested format doesn't match audit: fix a memory leak bug media: au0828: Fix NULL pointer dereference in au0828_analog_stream_enable() media: pvrusb2: Prevent a buffer overflow powerpc/numa: improve control of topology updates sched/core: Check quota and period overflow at usec to nsec conversion sched/core: Handle overflow in cpu_shares_write_u64 USB: core: Don't unbind interfaces following device reset failure x86/irq/64: Limit IST stack overflow check to #DB stack i40e: don't allow changes to HW VLAN stripping on active port VLANs RDMA/cxgb4: Fix null pointer dereference on alloc_skb failure hwmon: (vt1211) Use request_muxed_region for Super-IO accesses hwmon: (smsc47m1) Use request_muxed_region for Super-IO accesses hwmon: (smsc47b397) Use request_muxed_region for Super-IO accesses hwmon: (pc87427) Use request_muxed_region for Super-IO accesses hwmon: (f71805f) Use request_muxed_region for Super-IO accesses scsi: libsas: Do discovery on empty PHY to update PHY info mmc_spi: add a status check for spi_sync_locked mmc: sdhci-of-esdhc: add erratum eSDHC5 support mmc: sdhci-of-esdhc: add erratum eSDHC-A001 and A-008358 support PM / core: Propagate dev->power.wakeup_path when no callbacks extcon: arizona: Disable mic detect if running when driver is removed s390: cio: fix cio_irb declaration cpufreq: ppc_cbe: fix possible object reference leak cpufreq/pasemi: fix possible object reference leak cpufreq: pmac32: fix possible object reference leak x86/build: Keep local relocations with ld.lld iio: ad_sigma_delta: Properly handle SPI bus locking vs CS assertion iio: hmc5843: fix potential NULL pointer dereferences iio: common: ssp_sensors: Initialize calculated_time in ssp_common_process_data rtlwifi: fix a potential NULL pointer dereference brcmfmac: fix missing checks for kmemdup b43: shut up clang -Wuninitialized variable warning brcmfmac: convert dev_init_lock mutex to completion brcmfmac: fix race during disconnect when USB completion is in progress scsi: ufs: Fix regulator load and icc-level configuration scsi: ufs: Avoid configuring regulator with undefined voltage range arm64: cpu_ops: fix a leaked reference by adding missing of_node_put x86/ia32: Fix ia32_restore_sigcontext() AC leak chardev: add additional check for minor range overlap HID: core: move Usage Page concatenation to Main item ASoC: eukrea-tlv320: fix a leaked reference by adding missing of_node_put ASoC: fsl_utils: fix a leaked reference by adding missing of_node_put cxgb3/l2t: Fix undefined behaviour spi: tegra114: reset controller on probe media: wl128x: prevent two potential buffer overflows virtio_console: initialize vtermno value for ports tty: ipwireless: fix missing checks for ioremap rcutorture: Fix cleanup path for invalid torture_type strings usb: core: Add PM runtime calls to usb_hcd_platform_shutdown scsi: qla4xxx: avoid freeing unallocated dma memory media: m88ds3103: serialize reset messages in m88ds3103_set_frontend media: go7007: avoid clang frame overflow warning with KASAN media: saa7146: avoid high stack usage with clang scsi: lpfc: Fix SLI3 commands being issued on SLI4 devices spi : spi-topcliff-pch: Fix to handle empty DMA buffers spi: rspi: Fix sequencer reset during initialization spi: Fix zero length xfer bug ASoC: davinci-mcasp: Fix clang warning without CONFIG_PM ipv6: Consider sk_bound_dev_if when binding a raw socket to an address llc: fix skb leak in llc_build_and_send_ui_pkt() net-gro: fix use-after-free read in napi_gro_frags() net: stmmac: fix reset gpio free missing usbnet: fix kernel crash after disconnect tipc: Avoid copying bytes beyond the supplied data bnxt_en: Fix aggregation buffer leak under OOM condition. net: mvpp2: fix bad MVPP2_TXQ_SCHED_TOKEN_CNTR_REG queue value crypto: vmx - ghash: do nosimd fallback manually xen/pciback: Don't disable PCI_COMMAND on PCI device reset. Revert "tipc: fix modprobe tipc failed after switch order of device registration" tipc: fix modprobe tipc failed after switch order of device registration -v2 sparc64: Fix regression in non-hypervisor TLB flush xcall include/linux/bitops.h: sanitize rotate primitives xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic() usb: xhci: avoid null pointer deref when bos field is NULL USB: Fix slab-out-of-bounds write in usb_get_bos_descriptor USB: sisusbvga: fix oops in error path of sisusb_probe USB: Add LPM quirk for Surface Dock GigE adapter USB: rio500: refuse more than one device at a time USB: rio500: fix memory leak in close after disconnect media: usb: siano: Fix general protection fault in smsusb media: usb: siano: Fix false-positive "uninitialized variable" warning media: smsusb: better handle optional alignment scsi: zfcp: fix missing zfcp_port reference put on -EBUSY from port_remove scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs) Btrfs: fix race updating log root item during fsync ALSA: hda/realtek - Set default power save node to 0 drm/nouveau/i2c: Disable i2c bus access after ->fini() tty: serial: msm_serial: Fix XON/XOFF tty: max310x: Fix external crystal register setup memcg: make it work on sparse non-0-node systems kernel/signal.c: trace_signal_deliver when signal_group_exit CIFS: cifs_read_allocate_pages: don't iterate through whole page array on ENOMEM binder: Replace "%p" with "%pK" for stable binder: replace "%p" with "%pK" net: create skb_gso_validate_mac_len() bnx2x: disable GSO where gso_size is too big for hardware brcmfmac: Add length checks on firmware events brcmfmac: screening firmware event packet brcmfmac: revise handling events in receive path brcmfmac: fix incorrect event channel deduction brcmfmac: add length checks in scheduled scan result handler brcmfmac: add subtype check for event handling in data path userfaultfd: don't pin the user memory in userfaultfd_file_create() Revert "x86/build: Move _etext to actual end of .text" net: cdc_ncm: GetNtbFormat endian fix usb: gadget: fix request length error for isoc transfer media: uvcvideo: Fix uvc_alloc_entity() allocation alignment ethtool: fix potential userspace buffer overflow neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit net/mlx4_en: ethtool, Remove unsupported SFP EEPROM high pages query net: rds: fix memory leak in rds_ib_flush_mr_pool pktgen: do not sleep with the thread lock held. rcu: locking and unlocking need to always be at least barriers parisc: Use implicit space register selection for loading the coherence index of I/O pdirs fuse: fallocate: fix return with locked inode MIPS: pistachio: Build uImage.gz by default genwqe: Prevent an integer overflow in the ioctl drm/gma500/cdv: Check vbt config bits when detecting lvds panels fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock fuse: Add FOPEN_STREAM to use stream_open() ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled ethtool: check the return value of get_regs_len Linux 4.4.181 Change-Id: Ibadc58ab76330698ff36ffdc0ca8c9d52ce36f9e Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
| * mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versionsPeter Zijlstra2019-06-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 29da93fea3ea39ab9b12270cc6be1b70ef201c9e ] Randy reported objtool triggered on his (GCC-7.4) build: lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x315: call to __ubsan_handle_add_overflow() with UACCESS enabled lib/strnlen_user.o: warning: objtool: strnlen_user()+0x337: call to __ubsan_handle_sub_overflow() with UACCESS enabled This is due to UBSAN generating signed-overflow-UB warnings where it should not. Prior to GCC-8 UBSAN ignored -fwrapv (which the kernel uses through -fno-strict-overflow). Make the functions use 'unsigned long' throughout. Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: luto@kernel.org Link: http://lkml.kernel.org/r/20190424072208.754094071@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* | UPSTREAM: unsafe_[get|put]_user: change interface to use a error target labelLinus Torvalds2016-09-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I initially added the unsafe_[get|put]_user() helpers in commit 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses"), I made the mistake of modeling the interface on our traditional __[get|put]_user() functions, which return zero on success, or -EFAULT on failure. That interface is fairly easy to use, but it's actually fairly nasty for good code generation, since it essentially forces the caller to check the error value for each access. In particular, since the error handling is already internally implemented with an exception handler, and we already use "asm goto" for various other things, we could fairly easily make the error cases just jump directly to an error label instead, and avoid the need for explicit checking after each operation. So switch the interface to pass in an error label, rather than checking the error value in the caller. Best do it now before we start growing more users (the signal handling code in particular would be a good place to use the new interface). So rather than if (unsafe_get_user(x, ptr)) ... handle error .. the interface is now unsafe_get_user(x, ptr, label); where an error during the user mode fetch will now just cause a jump to 'label' in the caller. Right now the actual _implementation_ of this all still ends up being a "if (err) goto label", and does not take advantage of any exception label tricks, but for "unsafe_put_user()" in particular it should be fairly straightforward to convert to using the exception table model. Note that "unsafe_get_user()" is much harder to convert to a clever exception table model, because current versions of gcc do not allow the use of "asm goto" (for the exception) with output values (for the actual value to be fetched). But that is hopefully not a limitation in the long term. [ Also note that it might be a good idea to switch unsafe_get_user() to actually _return_ the value it fetches from user space, but this commit only changes the error handling semantics ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: Ib905a84a04d46984320f6fd1056da4d72f3d6b53 (cherry picked from commit 1bd4403d86a1c06cb6cc9ac87664a0c9d3413d51) Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
* | UPSTREAM: Use the new batched user accesses in generic user string handlingLinus Torvalds2016-09-06
|/ | | | | | | | | | | | | | | | | This converts the generic user string functions to use the batched user access functions. It makes a big difference on Skylake, which is the first x86 microarchitecture to implement SMAP. The STAC/CLAC instructions are not very fast, and doing them for each access inside the loop that copies strings from user space (which is what the pathname handling does for every pathname the kernel uses, for example) is very inefficient. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: Ic39a686b4bb1ad9cd16ad0887bb669beed6fe8aa (cherry picked from commit 9fd4470ff4974c41b1db43c3b355b9085af9c12a) Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2015-06-22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes are: - lockless wakeup support for futexes and IPC message queues (Davidlohr Bueso, Peter Zijlstra) - Replace spinlocks with atomics in thread_group_cputimer(), to improve scalability (Jason Low) - NUMA balancing improvements (Rik van Riel) - SCHED_DEADLINE improvements (Wanpeng Li) - clean up and reorganize preemption helpers (Frederic Weisbecker) - decouple page fault disabling machinery from the preemption counter, to improve debuggability and robustness (David Hildenbrand) - SCHED_DEADLINE documentation updates (Luca Abeni) - topology CPU masks cleanups (Bartosz Golaszewski) - /proc/sched_debug improvements (Srikar Dronamraju)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits) sched/deadline: Remove needless parameter in dl_runtime_exceeded() sched: Remove superfluous resetting of the p->dl_throttled flag sched/deadline: Drop duplicate init_sched_dl_class() declaration sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target sched/deadline: Make init_sched_dl_class() __init sched/deadline: Optimize pull_dl_task() sched/preempt: Add static_key() to preempt_notifiers sched/preempt: Fix preempt notifiers documentation about hlist_del() within unsafe iteration sched/stop_machine: Fix deadlock between multiple stop_two_cpus() sched/debug: Add sum_sleep_runtime to /proc/<pid>/sched sched/debug: Replace vruntime with wait_sum in /proc/sched_debug sched/debug: Properly format runnable tasks in /proc/sched_debug sched/numa: Only consider less busy nodes as numa balancing destinations Revert 095bebf61a46 ("sched/numa: Do not move past the balance point if unbalanced") sched/fair: Prevent throttling in early pick_next_task_fair() preempt: Reorganize the notrace definitions a bit preempt: Use preempt_schedule_context() as the official tracing preemption point sched: Make preempt_schedule_context() function-tracing safe x86: Remove cpu_sibling_mask() and cpu_core_mask() x86: Replace cpu_**_mask() with topology_**_cpumask() ...
| * mm/uaccess, mm/fault: Clarify that uaccess may only sleep if pagefaults are ↵David Hildenbrand2015-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled In general, non-atomic variants of user access functions must not sleep if pagefaults are disabled. Let's update all relevant comments in uaccess code. This also reflects the might_sleep() checks in might_fault(). Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-4-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | lib: Clarify the return value of strnlen_user()Jan Kara2015-06-03
| | | | | | | | | | | | | | | | | | | | strnlen_user() can return a number in a range 0 to count + sizeof(unsigned long) - 1. Clarify the comment at the top of the function so that users don't think the function returns at most count+1. Signed-off-by: Jan Kara <jack@suse.cz> [ Also added commentary about preferably not using this function ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib: Fix strnlen_user() to not touch memory after specified maximumJan Kara2015-06-02
|/ | | | | | | | | | | | | | If the specified maximum length of the string is a multiple of unsigned long, we would load one long behind the specified maximum. If that happens to be in a next page, we can hit a page fault although we were not expected to. Fix the off-by-one bug in the test whether we are at the end of the specified range. Signed-off-by: Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: Fix generic strnlen_user for 32-bit big-endian machinesPaul Mackerras2012-05-27
| | | | | | | | | | | The aligned_byte_mask() definition is wrong for 32-bit big-endian machines: the "7-(n)" part of the definition assumes a long is 8 bytes. This fixes it by using BITS_PER_LONG - 8 instead of 8*7. Tested on 32-bit and 64-bit PowerPC. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: add generic strnlen_user() functionLinus Torvalds2012-05-26
This adds a new generic optimized strnlen_user() function that uses the <asm/word-at-a-time.h> infrastructure to portably do efficient string handling. In many ways, strnlen is much simpler than strncpy, and in particular we can always pre-align the words we load from memory. That means that all the worries about alignment etc are a non-issue, so this one can easily be used on any architecture. You obviously do have to do the appropriate word-at-a-time.h macros. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>