65 Commits

Author SHA1 Message Date
Michael Bestas
ada87b00e9 Merge tag 'v4.4.278' of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into android-msm-wahoo-4.4
This is the 4.4.278 stable release

# gpg: Signature made Wed Aug  4 12:56:55 2021 EEST
# gpg:                using RSA key 647F28654894E3BD457199BE38DBBDC86092693E
# gpg: Good signature from "Greg Kroah-Hartman <gregkh@kernel.org>" [full]
# gpg: gregkh@kernel.org: Verified 28 signatures in the past 11 days.  Encrypted
#      0 messages.

# By Pavel Skripkin (4) and others
# Via Greg Kroah-Hartman
* tag 'v4.4.278' of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable:
  Linux 4.4.278
  sis900: Fix missing pci_disable_device() in probe and remove
  tulip: windbond-840: Fix missing pci_disable_device() in probe and remove
  net: llc: fix skb_over_panic
  mlx4: Fix missing error code in mlx4_load_one()
  tipc: fix sleeping in tipc accept routine
  netfilter: nft_nat: allow to specify layer 4 protocol NAT only
  cfg80211: Fix possible memory leak in function cfg80211_bss_update
  x86/asm: Ensure asm/proto.h can be included stand-alone
  NIU: fix incorrect error return, missed in previous revert
  can: esd_usb2: fix memory leak
  can: ems_usb: fix memory leak
  can: usb_8dev: fix memory leak
  ocfs2: issue zeroout to EOF blocks
  ocfs2: fix zero out valid data
  ARM: ensure the signal page contains defined contents
  lib/string.c: add multibyte memset functions
  ARM: dts: versatile: Fix up interrupt controller node names
  hfs: add lock nesting notation to hfs_find_init
  hfs: fix high memory mapping in hfs_bnode_read
  hfs: add missing clean-up in hfs_fill_super
  sctp: move 198 addresses from unusable to private scope
  net/802/garp: fix memleak in garp_request_join()
  net/802/mrp: fix memleak in mrp_request_join()
  workqueue: fix UAF in pwq_unbound_release_workfn()
  af_unix: fix garbage collect vs MSG_PEEK
  net: split out functions related to registering inflight socket files

Change-Id: I6c1b0a69611a9f446b46b9a886637941f7f9c833
2021-08-05 14:01:54 +03:00
Matthew Wilcox
5ed05c5540 lib/string.c: add multibyte memset functions
commit 3b3c4babd898715926d24ae10aa64778ace33aae upstream.

Patch series "Multibyte memset variations", v4.

A relatively common idiom we're missing is a function to fill an area of
memory with a pattern which is larger than a single byte.  I first
noticed this with a zram patch which wanted to fill a page with an
'unsigned long' value.  There turn out to be quite a few places in the
kernel which can benefit from using an optimised function rather than a
loop; sometimes text size, sometimes speed, and sometimes both.  The
optimised PowerPC version (not included here) improves performance by
about 30% on POWER8 on just the raw memset_l().

Most of the extra lines of code come from the three testcases I added.

This patch (of 8):

memset16(), memset32() and memset64() are like memset(), but allow the
caller to fill the destination with a value larger than a single byte.
memset_l() and memset_p() allow the caller to use unsigned long and
pointer values respectively.

Link: http://lkml.kernel.org/r/20170720184539.31609-2-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-04 11:56:45 +02:00
Michael Bestas
bbea1101c3 Merge tag 'v4.4.258' into android-msm-wahoo-4.4
This is the 4.4.258 stable release

# gpg: Signature made Tue Feb 23 14:58:32 2021 EET
# gpg:                using RSA key 647F28654894E3BD457199BE38DBBDC86092693E
# gpg: Good signature from "Greg Kroah-Hartman <gregkh@kernel.org>" [full]
# gpg: gregkh@kernel.org: Verified 9 signatures in the past 2 hours.  Encrypted
#      0 messages.

# By Jan Beulich (8) and others
# Via Greg Kroah-Hartman
* tag 'v4.4.258':
  Linux 4.4.258
  kvm: check tlbs_dirty directly
  scsi: qla2xxx: Fix crash during driver load on big endian machines
  xen-blkback: fix error handling in xen_blkbk_map()
  xen-scsiback: don't "handle" error by BUG()
  xen-netback: don't "handle" error by BUG()
  xen-blkback: don't "handle" error by BUG()
  xen/arm: don't ignore return errors from set_phys_to_machine
  Xen/gntdev: correct error checking in gntdev_map_grant_pages()
  Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()
  Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()
  Xen/x86: don't bail early from clear_foreign_p2m_mapping()
  tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
  tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount
  trace: Use -mcount-record for dynamic ftrace
  x86/build: Disable CET instrumentation in the kernel for 32-bit too
  vsock: fix locking in vsock_shutdown()
  net: watchdog: hold device global xmit lock during tx disable
  usb: dwc3: ulpi: Replace CPU-based busyloop with Protocol-based one
  usb: dwc3: ulpi: fix checkpatch warning
  h8300: fix PREEMPTION build, TI_PRE_COUNT undefined
  netfilter: xt_recent: Fix attempt to update deleted entry
  memblock: do not start bottom-up allocations with kernel_end
  squashfs: add more sanity checks in xattr id lookup
  squashfs: add more sanity checks in inode lookup
  squashfs: add more sanity checks in id lookup
  memcg: fix a crash in wb_workfn when a device disappears
  include/trace/events/writeback.h: fix -Wstringop-truncation warnings
  lib/string: Add strscpy_pad() function
  SUNRPC: Handle 0 length opaque XDR object data properly
  SUNRPC: Move simple_get_bytes and simple_get_netobj into private header
  iwlwifi: mvm: guard against device removal in reprobe
  iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap
  af_key: relax availability checks for skb size calculation
  fgraph: Initialize tracing_graph_pause at task creation
  tracing: Do not count ftrace events in top level enable output

Change-Id: I1b31d727428550a5170b62cd709d4ee850f0b66d
2021-07-24 19:19:00 +03:00
Tobin C. Harding
651b709117 lib/string: Add strscpy_pad() function
[ Upstream commit 458a3bf82df4fe1f951d0f52b1e0c1e9d5a88a3b ]

We have a function to copy strings safely and we have a function to copy
strings and zero the tail of the destination (if source string is
shorter than destination buffer) but we do not have a function to do
both at once.  This means developers must write this themselves if they
desire this functionality.  This is a chore, and also leaves us open to
off by one errors unnecessarily.

Add a function that calls strscpy() then memset()s the tail to zero if
the source string is shorter than the destination buffer.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-23 13:58:12 +01:00
Nathan Chancellor
58adc31dac Merge 4.4.241 into android-msm-wahoo-4.4
Changes in 4.4.241: (113 commits)
        ibmveth: Identify ingress large send packets.
        tipc: fix the skb_unshare() in tipc_buf_append()
        net/ipv4: always honour route mtu during forwarding
        r8169: fix data corruption issue on RTL8402
        ALSA: bebob: potential info leak in hwdep_read()
        mm/kasan: print name of mem[set,cpy,move]() caller in report
        mm/kasan: add API to check memory regions
        compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()
        compiler.h: Add read_word_at_a_time() function.
        lib/strscpy: Shut up KASAN false-positives in strscpy()
        x86/mm/ptdump: Fix soft lockup in page table walker
        net: hdlc: In hdlc_rcv, check to make sure dev is an HDLC device
        net: hdlc_raw_eth: Clear the IFF_TX_SKB_SHARING flag after calling ether_setup
        nfc: Ensure presence of NFC_ATTR_FIRMWARE_NAME attribute in nfc_genl_fw_download()
        tcp: fix to update snd_wl1 in bulk receiver fast path
        icmp: randomize the global rate limiter
        cifs: remove bogus debug code
        ima: Don't ignore errors from crypto_shash_update()
        EDAC/i5100: Fix error handling order in i5100_init_one()
        crypto: ixp4xx - Fix the size used in a 'dma_free_coherent()' call
        media: Revert "media: exynos4-is: Add missed check for pinctrl_lookup_state()"
        media: m5mols: Check function pointer in m5mols_sensor_power
        media: omap3isp: Fix memleak in isp_probe
        crypto: omap-sham - fix digcnt register handling with export/import
        media: tc358743: initialize variable
        media: ti-vpe: Fix a missing check and reference count leak
        ath6kl: prevent potential array overflow in ath6kl_add_new_sta()
        ath9k: Fix potential out of bounds in ath9k_htc_txcompletion_cb()
        wcn36xx: Fix reported 802.11n rx_highest rate wcn3660/wcn3680
        mwifiex: Do not use GFP_KERNEL in atomic context
        drm/gma500: fix error check
        scsi: qla4xxx: Fix an error handling path in 'qla4xxx_get_host_stats()'
        scsi: csiostor: Fix wrong return value in csio_hw_prep_fw()
        backlight: sky81452-backlight: Fix refcount imbalance on error
        VMCI: check return value of get_user_pages_fast() for errors
        tty: serial: earlycon dependency
        tty: hvcs: Don't NULL tty->driver_data until hvcs_cleanup()
        pty: do tty_flip_buffer_push without port->lock in pty_write
        drivers/virt/fsl_hypervisor: Fix error handling path
        video: fbdev: vga16fb: fix setting of pixclock because a pass-by-value error
        video: fbdev: sis: fix null ptr dereference
        HID: roccat: add bounds checking in kone_sysfs_write_settings()
        ath6kl: wmi: prevent a shift wrapping bug in ath6kl_wmi_delete_pstream_cmd()
        misc: mic: scif: Fix error handling path
        ALSA: seq: oss: Avoid mutex lock for a long-time ioctl
        quota: clear padding in v2r1_mem2diskdqb()
        net: enic: Cure the enic api locking trainwreck
        mfd: sm501: Fix leaks in probe()
        usb: gadget: u_ether: enable qmult on SuperSpeed Plus as well
        nl80211: fix non-split wiphy information
        mwifiex: fix double free
        net: korina: fix kfree of rx/tx descriptor array
        IB/mlx4: Adjust delayed work when a dup is observed
        powerpc/pseries: Fix missing of_node_put() in rng_init()
        powerpc/icp-hv: Fix missing of_node_put() in success path
        mtd: lpddr: fix excessive stack usage with clang
        mtd: mtdoops: Don't write panic data twice
        ARM: 9007/1: l2c: fix prefetch bits init in L2X0_AUX_CTRL using DT values
        powerpc/tau: Use appropriate temperature sample interval
        powerpc/tau: Remove duplicated set_thresholds() call
        powerpc/tau: Disable TAU between measurements
        perf intel-pt: Fix "context_switch event has no tid" error
        kdb: Fix pager search for multi-line strings
        powerpc/perf/hv-gpci: Fix starting index value
        cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
        lib/crc32.c: fix trivial typo in preprocessor condition
        vfio/pci: Clear token on bypass registration failure
        Input: imx6ul_tsc - clean up some errors in imx6ul_tsc_resume()
        Input: ep93xx_keypad - fix handling of platform_get_irq() error
        Input: omap4-keypad - fix handling of platform_get_irq() error
        Input: sun4i-ps2 - fix handling of platform_get_irq() error
        KVM: x86: emulating RDPID failure shall return #UD rather than #GP
        memory: omap-gpmc: Fix a couple off by ones
        memory: fsl-corenet-cf: Fix handling of platform_get_irq() error
        arm64: dts: zynqmp: Remove additional compatible string for i2c IPs
        powerpc/powernv/dump: Fix race while processing OPAL dump
        media: firewire: fix memory leak
        media: ati_remote: sanity check for both endpoints
        media: exynos4-is: Fix several reference count leaks due to pm_runtime_get_sync
        media: exynos4-is: Fix a reference count leak due to pm_runtime_get_sync
        media: exynos4-is: Fix a reference count leak
        media: bdisp: Fix runtime PM imbalance on error
        media: media/pci: prevent memory leak in bttv_probe
        media: uvcvideo: Ensure all probed info is returned to v4l2
        mmc: sdio: Check for CISTPL_VERS_1 buffer size
        media: saa7134: avoid a shift overflow
        ntfs: add check for mft record size in superblock
        PM: hibernate: remove the bogus call to get_gendisk() in software_resume()
        scsi: mvumi: Fix error return in mvumi_io_attach()
        scsi: target: core: Add CONTROL field for trace events
        usb: gadget: function: printer: fix use-after-free in __lock_acquire
        udf: Limit sparing table size
        udf: Avoid accessing uninitialized data on failed inode read
        ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()
        misc: rtsx: Fix memory leak in rtsx_pci_probe
        reiserfs: only call unlock_new_inode() if I_NEW
        xfs: make sure the rt allocator doesn't run off the end
        usb: ohci: Default to per-port over-current protection
        Bluetooth: Only mark socket zapped after unlocking
        scsi: ibmvfc: Fix error return in ibmvfc_probe()
        brcmsmac: fix memory leak in wlc_phy_attach_lcnphy
        rtl8xxxu: prevent potential memory leak
        Fix use after free in get_capset_info callback.
        tty: ipwireless: fix error handling
        ipvs: Fix uninit-value in do_ip_vs_set_ctl()
        reiserfs: Fix memory leak in reiserfs_parse_options()
        brcm80211: fix possible memleak in brcmf_proto_msgbuf_attach
        usb: core: Solve race condition in anchor cleanup functions
        ath10k: check idx validity in __ath10k_htt_rx_ring_fill_n()
        net: korina: cast KSEG0 address to pointer in kfree
        usb: cdc-acm: add quirk to blacklist ETAS ES58X devices
        USB: cdc-wdm: Make wdm_flush() interruptible and add wdm_fsync().
        Linux 4.4.241

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
2020-10-29 13:14:11 -07:00
Andrey Ryabinin
a3eedd10c0 lib/strscpy: Shut up KASAN false-positives in strscpy()
commit 1a3241ff10d038ecd096d03380327f2a0b5840a6 upstream.

strscpy() performs the word-at-a-time optimistic reads.  So it may may
access the memory past the end of the object, which is perfectly fine
since strscpy() doesn't use that (past-the-end) data and makes sure the
optimistic read won't cross a page boundary.

Use new read_word_at_a_time() to shut up the KASAN.

Note that this potentially could hide some bugs.  In example bellow,
stscpy() will copy more than we should (1-3 extra uninitialized bytes):

        char dst[8];
        char *src;

        src = kmalloc(5, GFP_KERNEL);
        memset(src, 0xff, 5);
        strscpy(dst, src, 8);

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 09:03:00 +01:00
Nathan Chancellor
44902e73a4 Merge 4.4.238 into android-msm-wahoo-4.4
Changes in 4.4.238: (86 commits)
        af_key: pfkey_dump needs parameter validation
        KVM: fix memory leak in kvm_io_bus_unregister_dev()
        kprobes: fix kill kprobe which has been marked as gone
        ftrace: Setup correct FTRACE_FL_REGS flags for module
        RDMA/ucma: ucma_context reference leak in error path
        mtd: Fix comparison in map_word_andequal()
        hdlc_ppp: add range checks in ppp_cp_parse_cr()
        tipc: use skb_unshare() instead in tipc_buf_append()
        net: add __must_check to skb_put_padto()
        ip: fix tos reflection in ack and reset packets
        serial: 8250: Avoid error message on reprobe
        scsi: aacraid: fix illegal IO beyond last LBA
        m68k: q40: Fix info-leak in rtc_ioctl
        gma/gma500: fix a memory disclosure bug due to uninitialized bytes
        ASoC: kirkwood: fix IRQ error handling
        PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out
        mtd: cfi_cmdset_0002: don't free cfi->cfiq in error path of cfi_amdstd_setup()
        mfd: mfd-core: Protect against NULL call-back function pointer
        tracing: Adding NULL checks for trace_array descriptor pointer
        bcache: fix a lost wake-up problem caused by mca_cannibalize_lock
        xfs: fix attr leaf header freemap.size underflow
        kernel/sys.c: avoid copying possible padding bytes in copy_to_user
        neigh_stat_seq_next() should increase position index
        rt_cpu_seq_next should increase position index
        seqlock: Require WRITE_ONCE surrounding raw_seqcount_barrier
        ACPI: EC: Reference count query handlers under lock
        tracing: Set kernel_stack's caller size properly
        ar5523: Add USB ID of SMCWUSBT-G2 wireless adapter
        Bluetooth: Fix refcount use-after-free issue
        mm: pagewalk: fix termination condition in walk_pte_range()
        Bluetooth: prefetch channel before killing sock
        skbuff: fix a data race in skb_queue_len()
        audit: CONFIG_CHANGE don't log internal bookkeeping as an event
        selinux: sel_avc_get_stat_idx should increase position index
        scsi: lpfc: Fix RQ buffer leakage when no IOCBs available
        drm/omap: fix possible object reference leak
        dmaengine: tegra-apb: Prevent race conditions on channel's freeing
        media: go7007: Fix URB type for interrupt handling
        Bluetooth: guard against controllers sending zero'd events
        drm/amdgpu: increase atombios cmd timeout
        Bluetooth: L2CAP: handle l2cap config request during open state
        media: tda10071: fix unsigned sign extension overflow
        tpm: ibmvtpm: Wait for buffer to be set before proceeding
        tracing: Use address-of operator on section symbols
        serial: 8250_omap: Fix sleeping function called from invalid context during probe
        SUNRPC: Fix a potential buffer overflow in 'svc_print_xprts()'
        ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len
        ALSA: usb-audio: Fix case when USB MIDI interface has more than one extra endpoint descriptor
        mm/filemap.c: clear page error before actual read
        mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area
        KVM: Remove CREATE_IRQCHIP/SET_PIT2 race
        bdev: Reduce time holding bd_mutex in sync in blkdev_close()
        drivers: char: tlclk.c: Avoid data race between init and interrupt handler
        dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion
        atm: fix a memory leak of vcc->user_back
        phy: samsung: s5pv210-usb2: Add delay after reset
        Bluetooth: Handle Inquiry Cancel error after Inquiry Complete
        USB: EHCI: ehci-mv: fix error handling in mv_ehci_probe()
        tty: serial: samsung: Correct clock selection logic
        ALSA: hda: Fix potential race in unsol event handler
        fuse: don't check refcount after stealing page
        USB: EHCI: ehci-mv: fix less than zero comparison of an unsigned int
        e1000: Do not perform reset in reset_task if we are already down
        printk: handle blank console arguments passed in.
        vfio/pci: fix memory leaks of eventfd ctx
        perf kcore_copy: Fix module map when there are no modules loaded
        mtd: rawnand: omap_elm: Fix runtime PM imbalance on error
        ceph: fix potential race in ceph_check_caps
        mtd: parser: cmdline: Support MTD names containing one or more colons
        x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline
        vfio/pci: Clear error and request eventfd ctx after releasing
        vfio/pci: fix racy on error and request eventfd ctx
        s390/init: add missing __init annotations
        mwifiex: Increase AES key storage size to 256 bits
        batman-adv: bla: fix type misuse for backbone_gw hash indexing
        atm: eni: fix the missed pci_disable_device() for eni_init_one()
        batman-adv: mcast/TT: fix wrongly dropped or rerouted packets
        ALSA: asihpi: fix iounmap in error handler
        MIPS: Add the missing 'CPU_1074K' into __get_cpu_type()
        tty: vt, consw->con_scrolldelta cleanup
        kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
        lib/string.c: implement stpcpy
        ata: define AC_ERR_OK
        ata: make qc_prep return ata_completion_errors
        ata: sata_mv, avoid trigerrable BUG_ON
        Linux 4.4.238

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
2020-10-01 10:14:23 -07:00
Nick Desaulniers
cb8fce7e59 lib/string.c: implement stpcpy
commit 1e1b6d63d6340764e00356873e5794225a2a03ea upstream.

LLVM implemented a recent "libcall optimization" that lowers calls to
`sprintf(dest, "%s", str)` where the return value is used to
`stpcpy(dest, str) - dest`.

This generally avoids the machinery involved in parsing format strings.
`stpcpy` is just like `strcpy` except it returns the pointer to the new
tail of `dest`.  This optimization was introduced into clang-12.

Implement this so that we don't observe linkage failures due to missing
symbol definitions for `stpcpy`.

Similar to last year's fire drill with: commit 5f074f3e192f
("lib/string.c: implement a basic bcmp")

The kernel is somewhere between a "freestanding" environment (no full
libc) and "hosted" environment (many symbols from libc exist with the
same type, function signature, and semantics).

As Peter Anvin notes, there's not really a great way to inform the
compiler that you're targeting a freestanding environment but would like
to opt-in to some libcall optimizations (see pr/47280 below), rather
than opt-out.

Arvind notes, -fno-builtin-* behaves slightly differently between GCC
and Clang, and Clang is missing many __builtin_* definitions, which I
consider a bug in Clang and am working on fixing.

Masahiro summarizes the subtle distinction between compilers justly:
  To prevent transformation from foo() into bar(), there are two ways in
  Clang to do that; -fno-builtin-foo, and -fno-builtin-bar.  There is
  only one in GCC; -fno-buitin-foo.

(Any difference in that behavior in Clang is likely a bug from a missing
__builtin_* definition.)

Masahiro also notes:
  We want to disable optimization from foo() to bar(),
  but we may still benefit from the optimization from
  foo() into something else. If GCC implements the same transform, we
  would run into a problem because it is not -fno-builtin-bar, but
  -fno-builtin-foo that disables that optimization.

  In this regard, -fno-builtin-foo would be more future-proof than
  -fno-built-bar, but -fno-builtin-foo is still potentially overkill. We
  may want to prevent calls from foo() being optimized into calls to
  bar(), but we still may want other optimization on calls to foo().

It seems that compilers today don't quite provide the fine grain control
over which libcall optimizations pseudo-freestanding environments would
prefer.

Finally, Kees notes that this interface is unsafe, so we should not
encourage its use.  As such, I've removed the declaration from any
header, but it still needs to be exported to avoid linkage errors in
modules.

Reported-by: Sami Tolvanen <samitolvanen@google.com>
Suggested-by: Andy Lavr <andy.lavr@gmail.com>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200914161643.938408-1-ndesaulniers@google.com
Link: https://bugs.llvm.org/show_bug.cgi?id=47162
Link: https://bugs.llvm.org/show_bug.cgi?id=47280
Link: https://github.com/ClangBuiltLinux/linux/issues/1126
Link: https://man7.org/linux/man-pages/man3/stpcpy.3.html
Link: https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html
Link: https://reviews.llvm.org/D85963
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01 11:11:58 +02:00
Nathan Chancellor
79a097e001 Merge 4.4.179 into android-msm-wahoo-4.4
Changes in 4.4.179: (170 commits)
        arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals
        arm64: debug: Ensure debug handlers check triggering exception level
        ext4: cleanup bh release code in ext4_ind_remove_space()
        lib/int_sqrt: optimize initial value compute
        tty/serial: atmel: Add is_half_duplex helper
        mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified
        i2c: core-smbus: prevent stack corruption on read I2C_BLOCK_DATA
        Bluetooth: Fix decrementing reference count twice in releasing socket
        tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped
        CIFS: fix POSIX lock leak and invalid ptr deref
        h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux-
        tracing: kdb: Fix ftdump to not sleep
        gpio: gpio-omap: fix level interrupt idling
        sysctl: handle overflow for file-max
        enic: fix build warning without CONFIG_CPUMASK_OFFSTACK
        mm/cma.c: cma_declare_contiguous: correct err handling
        mm/page_ext.c: fix an imbalance with kmemleak
        mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512!
        mm/slab.c: kmemleak no scan alien caches
        ocfs2: fix a panic problem caused by o2cb_ctl
        f2fs: do not use mutex lock in atomic context
        fs/file.c: initialize init_files.resize_wait
        cifs: use correct format characters
        dm thin: add sanity checks to thin-pool and external snapshot creation
        cifs: Fix NULL pointer dereference of devname
        fs: fix guard_bio_eod to check for real EOD errors
        tools lib traceevent: Fix buffer overflow in arg_eval
        usb: chipidea: Grab the (legacy) USB PHY by phandle first
        scsi: core: replace GFP_ATOMIC with GFP_KERNEL in scsi_scan.c
        coresight: etm4x: Add support to enable ETMv4.2
        ARM: 8840/1: use a raw_spinlock_t in unwind
        mmc: omap: fix the maximum timeout setting
        e1000e: Fix -Wformat-truncation warnings
        IB/mlx4: Increase the timeout for CM cache
        scsi: megaraid_sas: return error when create DMA pool failed
        perf test: Fix failure of 'evsel-tp-sched' test on s390
        SoC: imx-sgtl5000: add missing put_device()
        media: sh_veu: Correct return type for mem2mem buffer helpers
        media: s5p-jpeg: Correct return type for mem2mem buffer helpers
        media: s5p-g2d: Correct return type for mem2mem buffer helpers
        media: mx2_emmaprp: Correct return type for mem2mem buffer helpers
        leds: lp55xx: fix null deref on firmware load failure
        kprobes: Prohibit probing on bsearch()
        ARM: 8833/1: Ensure that NEON code always compiles with Clang
        ALSA: PCM: check if ops are defined before suspending PCM
        bcache: fix input overflow to cache set sysfs file io_error_halflife
        bcache: fix input overflow to sequential_cutoff
        bcache: improve sysfs_strtoul_clamp()
        fbdev: fbmem: fix memory access if logo is bigger than the screen
        cdrom: Fix race condition in cdrom_sysctl_register
        ASoC: fsl-asoc-card: fix object reference leaks in fsl_asoc_card_probe
        soc: qcom: gsbi: Fix error handling in gsbi_probe()
        mt7601u: bump supported EEPROM version
        ARM: avoid Cortex-A9 livelock on tight dmb loops
        tty: increase the default flip buffer limit to 2*640K
        media: mt9m111: set initial frame size other than 0x0
        hwrng: virtio - Avoid repeated init of completion
        soc/tegra: fuse: Fix illegal free of IO base address
        hpet: Fix missing '=' character in the __setup() code of hpet_mmap_enable
        dmaengine: imx-dma: fix warning comparison of distinct pointer types
        netfilter: physdev: relax br_netfilter dependency
        media: s5p-jpeg: Check for fmt_ver_flag when doing fmt enumeration
        regulator: act8865: Fix act8600_sudcdc_voltage_ranges setting
        wlcore: Fix memory leak in case wl12xx_fetch_firmware failure
        x86/build: Mark per-CPU symbols as absolute explicitly for LLD
        dmaengine: tegra: avoid overflow of byte tracking
        drm/dp/mst: Configure no_stop_bit correctly for remote i2c xfers
        binfmt_elf: switch to new creds when switching to new mm
        kbuild: clang: choose GCC_TOOLCHAIN_DIR not on LD
        x86/build: Specify elf_i386 linker emulation explicitly for i386 objects
        x86: vdso: Use $LD instead of $CC to link
        x86/vdso: Drop implicit common-page-size linker flag
        lib/string.c: implement a basic bcmp
        tty: mark Siemens R3964 line discipline as BROKEN
        tty: ldisc: add sysctl to prevent autoloading of ldiscs
        ipv6: Fix dangling pointer when ipv6 fragment
        ipv6: sit: reset ip header pointer in ipip6_rcv
        net: rds: force to destroy connection if t_sock is NULL in rds_tcp_kill_sock().
        openvswitch: fix flow actions reallocation
        qmi_wwan: add Olicard 600
        sctp: initialize _pad of sockaddr_in before copying to user memory
        tcp: Ensure DCTCP reacts to losses
        netns: provide pure entropy for net_hash_mix()
        net: ethtool: not call vzalloc for zero sized memory request
        ip6_tunnel: Match to ARPHRD_TUNNEL6 for dev type
        ALSA: seq: Fix OOB-reads from strlcpy
        include/linux/bitrev.h: fix constant bitrev
        ASoC: fsl_esai: fix channel swap issue when stream starts
        block: do not leak memory in bio_copy_user_iov()
        genirq: Respect IRQCHIP_SKIP_SET_WAKE in irq_chip_set_wake_parent()
        ARM: dts: at91: Fix typo in ISC_D0 on PC9
        arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value
        xen: Prevent buffer overflow in privcmd ioctl
        sched/fair: Do not re-read ->h_load_next during hierarchical load calculation
        xtensa: fix return_address
        PCI: Add function 1 DMA alias quirk for Marvell 9170 SATA controller
        perf/core: Restore mmap record type correctly
        ext4: add missing brelse() in add_new_gdb_meta_bg()
        ext4: report real fs size after failed resize
        ALSA: echoaudio: add a check for ioremap_nocache
        ALSA: sb8: add a check for request_region
        IB/mlx4: Fix race condition between catas error reset and aliasguid flows
        mmc: davinci: remove extraneous __init annotation
        ALSA: opl3: fix mismatch between snd_opl3_drum_switch definition and declaration
        thermal/int340x_thermal: Add additional UUIDs
        thermal/int340x_thermal: fix mode setting
        tools/power turbostat: return the exit status of a command
        perf top: Fix error handling in cmd_top()
        perf evsel: Free evsel->counts in perf_evsel__exit()
        perf tests: Fix a memory leak of cpu_map object in the openat_syscall_event_on_all_cpus test
        perf tests: Fix a memory leak in test__perf_evsel__tp_sched_test()
        x86/hpet: Prevent potential NULL pointer dereference
        x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors
        iommu/vt-d: Check capability before disabling protected memory
        x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error
        fix incorrect error code mapping for OBJECTID_NOT_FOUND
        ext4: prohibit fstrim in norecovery mode
        rsi: improve kernel thread handling to fix kernel panic
        9p: do not trust pdu content for stat item size
        9p locks: add mount option for lock retry interval
        f2fs: fix to do sanity check with current segment number
        serial: uartps: console_setup() can't be placed to init section
        ARM: samsung: Limit SAMSUNG_PM_CHECK config option to non-Exynos platforms
        ACPI / SBS: Fix GPE storm on recent MacBookPro's
        cifs: fallback to older infolevels on findfirst queryinfo retry
        crypto: sha256/arm - fix crash bug in Thumb2 build
        crypto: sha512/arm - fix crash bug in Thumb2 build
        iommu/dmar: Fix buffer overflow during PCI bus notification
        ARM: 8839/1: kprobe: make patch_lock a raw_spinlock_t
        appletalk: Fix use-after-free in atalk_proc_exit
        lib/div64.c: off by one in shift
        include/linux/swap.h: use offsetof() instead of custom __swapoffset macro
        tpm/tpm_crb: Avoid unaligned reads in crb_recv()
        ovl: fix uid/gid when creating over whiteout
        appletalk: Fix compile regression
        bonding: fix event handling for stacked bonds
        net: atm: Fix potential Spectre v1 vulnerabilities
        net: bridge: multicast: use rcu to access port list from br_multicast_start_querier
        net: fou: do not use guehdr after iptunnel_pull_offloads in gue_udp_recv
        tcp: tcp_grow_window() needs to respect tcp_space()
        ipv4: recompile ip options in ipv4_link_failure
        ipv4: ensure rcu_read_lock() in ipv4_link_failure()
        crypto: crypto4xx - properly set IV after de- and encrypt
        modpost: file2alias: go back to simple devtable lookup
        modpost: file2alias: check prototype of handler
        tpm/tpm_i2c_atmel: Return -E2BIG when the transfer is incomplete
        KVM: x86: Don't clear EFER during SMM transitions for 32-bit vCPU
        iio/gyro/bmg160: Use millidegrees for temperature scale
        iio: ad_sigma_delta: select channel when reading register
        iio: adc: at91: disable adc channel interrupt in timeout case
        io: accel: kxcjk1013: restore the range after resume.
        staging: comedi: vmk80xx: Fix use of uninitialized semaphore
        staging: comedi: vmk80xx: Fix possible double-free of ->usb_rx_buf
        staging: comedi: ni_usb6501: Fix use of uninitialized mutex
        staging: comedi: ni_usb6501: Fix possible double-free of ->usb_rx_buf
        ALSA: core: Fix card races between register and disconnect
        crypto: x86/poly1305 - fix overflow during partial reduction
        arm64: futex: Restore oldval initialization to work around buggy compilers
        x86/kprobes: Verify stack frame on kretprobe
        kprobes: Mark ftrace mcount handler functions nokprobe
        kprobes: Fix error check when reusing optimized probes
        mac80211: do not call driver wake_tx_queue op during reconfig
        Revert "kbuild: use -Oz instead of -Os when using clang"
        sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup
        device_cgroup: fix RCU imbalance in error case
        mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n
        ALSA: info: Fix racy addition/deletion of nodes
        Revert "locking/lockdep: Add debug_locks check in __lock_downgrade()"
        kernel/sysctl.c: fix out-of-bounds access when setting file-max
        Linux 4.4.179

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Conflicts:
	Makefile
	fs/ext4/ioctl.c
2019-04-27 09:07:11 -07:00
Nick Desaulniers
780e236c37 lib/string.c: implement a basic bcmp
[ Upstream commit 5f074f3e192f10c9fade898b9b3b8812e3d83342 ]

A recent optimization in Clang (r355672) lowers comparisons of the
return value of memcmp against zero to comparisons of the return value
of bcmp against zero.  This helps some platforms that implement bcmp
more efficiently than memcmp.  glibc simply aliases bcmp to memcmp, but
an optimized implementation is in the works.

This results in linkage failures for all targets with Clang due to the
undefined symbol.  For now, just implement bcmp as a tailcail to memcmp
to unbreak the build.  This routine can be further optimized in the
future.

Other ideas discussed:

 * A weak alias was discussed, but breaks for architectures that define
   their own implementations of memcmp since aliases to declarations are
   not permitted (only definitions). Arch-specific memcmp
   implementations typically declare memcmp in C headers, but implement
   them in assembly.

 * -ffreestanding also is used sporadically throughout the kernel.

 * -fno-builtin-bcmp doesn't work when doing LTO.

Link: https://bugs.llvm.org/show_bug.cgi?id=41035
Link: https://code.woboq.org/userspace/glibc/string/memcmp.c.html#bcmp
Link: 8e16d73346
Link: https://github.com/ClangBuiltLinux/linux/issues/416
Link: http://lkml.kernel.org/r/20190313211335.165605-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reported-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: James Y Knight <jyknight@google.com>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-27 09:33:54 +02:00
Yueyao Zhu
475faf1252 lib/string: fix logic in sysfs_match_string
sysfs_streq() returns true when the strings are equal,
and sysfs_match_string should return the index when
sysfs_streq() returns true instead of false.

Bug: 33417679
Change-Id: I5686d019e3e60025eea2419445378e478a7cab37
2016-12-07 16:20:50 -08:00
Heikki Krogerus
4b859121fe FROMLIST: lib/string: add sysfs_match_string helper
Make a simple helper for matching strings with sysfs
attribute files. In most parts the same as match_string(),
except sysfs_match_string() uses sysfs_streq() instead of
strcmp() for matching. This is more convenient when used
with sysfs attributes.

BUG=chromium:622499
TEST=Build and Compile

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
(am from https://patchwork.kernel.org/patch/9445395/)

(cherry-pick from Chromium Ia324112f6468788e577aab5221f7f88f777bffe7)
Bug: 33417679
Signed-off-by: Yueyao Zhu <yueyao@google.com>

Change-Id: Iba236b0ce3dd4e3c1bd6808224c620fa8e14e5ee
2016-12-07 16:20:30 -08:00
Kees Cook
e0d61779d3 lib: move strtobool() to kstrtobool()
commit ef951599074ba4fad2d0efa0a977129b41e6d203 upstream.

Create the kstrtobool_from_user() helper and move strtobool() logic into
the new kstrtobool() (matching all the other kstrto* functions).
Provides an inline wrapper for existing strtobool() callers.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Amitkumar Karwar <akarwar@marvell.com>
Cc: Nishant Sarmukadam <nishants@marvell.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Steve French <sfrench@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 03:01:30 -04:00
Kees Cook
cc635b7985 UPSTREAM: lib: move strtobool() to kstrtobool()
Create the kstrtobool_from_user() helper and move strtobool() logic into
the new kstrtobool() (matching all the other kstrto* functions).
Provides an inline wrapper for existing strtobool() callers.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Amitkumar Karwar <akarwar@marvell.com>
Cc: Nishant Sarmukadam <nishants@marvell.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Steve French <sfrench@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ef951599074ba4fad2d0efa0a977129b41e6d203)
Signed-off-by: Yueyao Zhu <yueyao@google.com>

Change-Id: I04bb1df8719f664d4e35f557d0ebed4d4760d164
2016-10-14 14:31:46 -07:00
Andy Shevchenko
0056bc5c7a UPSTREAM: lib/string: introduce match_string() helper
Occasionally we have to search for an occurrence of a string in an array
of strings.  Make a simple helper for that purpose.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from 56b060814e2d87d6646a85a2f4609c73587399ca)
Signed-off-by: Yueyao Zhu <yueyao@google.com>

Change-Id: Ic674b6f0020ea400abb41267aa5c9e1c0347c385
2016-10-14 14:31:45 -07:00
Andy Shevchenko
3368e8fbcd lib/string.c: add ULL suffix to the constant definition
8-byte constant is too big for long and compiler complains about this.

  lib/string.c:907:20: warning: constant 0x0101010101010101 is so big it is long

Append ULL suffix to explicitly show its type.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-10 16:32:11 -08:00
Chris Metcalf
990486c8af strscpy: zero any trailing garbage bytes in the destination
It's possible that the destination can be shadowed in userspace
(as, for example, the perf buffers are now).  So we should take
care not to leak data that could be inspected by userspace.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-10-06 14:53:18 -04:00
Chris Metcalf
30035e4575 string: provide strscpy()
The strscpy() API is intended to be used instead of strlcpy(),
and instead of most uses of strncpy().

- Unlike strlcpy(), it doesn't read from memory beyond (src + size).

- Unlike strlcpy() or strncpy(), the API provides an easy way to check
  for destination buffer overflow: an -E2BIG error return value.

- The provided implementation is robust in the face of the source
  buffer being asynchronously changed during the copy, unlike the
  current implementation of strlcpy().

- Unlike strncpy(), the destination buffer will be NUL-terminated
  if the string in the source buffer is too long.

- Also unlike strncpy(), the destination buffer will not be updated
  beyond the NUL termination, avoiding strncpy's behavior of zeroing
  the entire tail end of the destination buffer.  (A memset() after
  the strscpy() can be used if this behavior is desired.)

- The implementation should be reasonably performant on all
  platforms since it uses the asm/word-at-a-time.h API rather than
  simple byte copy.  Kernel-to-kernel string copy is not considered
  to be performance critical in any case.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-09-10 15:36:59 -04:00
Rasmus Villemoes
94df290404 lib/string.c: introduce strreplace()
Strings are sometimes sanitized by replacing a certain character (often
'/') by another (often '!').  In a few places, this is done the same way
Schlemiel the Painter would do it.  Others are slightly smarter but still
do multiple strchr() calls.  Introduce strreplace() to do this using a
single function call and a single pass over the string.

One would expect the return value to be one of three things: void, s, or
the number of replacements made.  I chose the fourth, returning a pointer
to the end of the string.  This is more likely to be useful (for example
allowing the caller to avoid a strlen call).

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25 17:00:40 -07:00
Daniel Borkmann
7829fb09a2 lib: make memzero_explicit more robust against dead store elimination
In commit 0b053c9518 ("lib: memzero_explicit: use barrier instead
of OPTIMIZER_HIDE_VAR"), we made memzero_explicit() more robust in
case LTO would decide to inline memzero_explicit() and eventually
find out it could be elimiated as dead store.

While using barrier() works well for the case of gcc, recent efforts
from LLVMLinux people suggest to use llvm as an alternative to gcc,
and there, Stephan found in a simple stand-alone user space example
that llvm could nevertheless optimize and thus elimitate the memset().
A similar issue has been observed in the referenced llvm bug report,
which is regarded as not-a-bug.

Based on some experiments, icc is a bit special on its own, while it
doesn't seem to eliminate the memset(), it could do so with an own
implementation, and then result in similar findings as with llvm.

The fix in this patch now works for all three compilers (also tested
with more aggressive optimization levels). Arguably, in the current
kernel tree it's more of a theoretical issue, but imho, it's better
to be pedantic about it.

It's clearly visible with gcc/llvm though, with the below code: if we
would have used barrier() only here, llvm would have omitted clearing,
not so with barrier_data() variant:

  static inline void memzero_explicit(void *s, size_t count)
  {
    memset(s, 0, count);
    barrier_data(s);
  }

  int main(void)
  {
    char buff[20];
    memzero_explicit(buff, sizeof(buff));
    return 0;
  }

  $ gcc -O2 test.c
  $ gdb a.out
  (gdb) disassemble main
  Dump of assembler code for function main:
   0x0000000000400400  <+0>: lea   -0x28(%rsp),%rax
   0x0000000000400405  <+5>: movq  $0x0,-0x28(%rsp)
   0x000000000040040e <+14>: movq  $0x0,-0x20(%rsp)
   0x0000000000400417 <+23>: movl  $0x0,-0x18(%rsp)
   0x000000000040041f <+31>: xor   %eax,%eax
   0x0000000000400421 <+33>: retq
  End of assembler dump.

  $ clang -O2 test.c
  $ gdb a.out
  (gdb) disassemble main
  Dump of assembler code for function main:
   0x00000000004004f0  <+0>: xorps  %xmm0,%xmm0
   0x00000000004004f3  <+3>: movaps %xmm0,-0x18(%rsp)
   0x00000000004004f8  <+8>: movl   $0x0,-0x8(%rsp)
   0x0000000000400500 <+16>: lea    -0x18(%rsp),%rax
   0x0000000000400505 <+21>: xor    %eax,%eax
   0x0000000000400507 <+23>: retq
  End of assembler dump.

As gcc, clang, but also icc defines __GNUC__, it's sufficient to define
this in compiler-gcc.h only to be picked up. For a fallback or otherwise
unsupported compiler, we define it as a barrier. Similarly, for ecc which
does not support gcc inline asm.

Reference: https://llvm.org/bugs/show_bug.cgi?id=15495
Reported-by: Stephan Mueller <smueller@chronox.de>
Tested-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: mancha security <mancha1@zoho.com>
Cc: Mark Charlebois <charlebm@gmail.com>
Cc: Behan Webster <behanw@converseincode.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-04 17:49:51 +08:00
mancha security
0b053c9518 lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR
OPTIMIZER_HIDE_VAR(), as defined when using gcc, is insufficient to
ensure protection from dead store optimization.

For the random driver and crypto drivers, calls are emitted ...

  $ gdb vmlinux
  (gdb) disassemble memzero_explicit
  Dump of assembler code for function memzero_explicit:
    0xffffffff813a18b0 <+0>:	push   %rbp
    0xffffffff813a18b1 <+1>:	mov    %rsi,%rdx
    0xffffffff813a18b4 <+4>:	xor    %esi,%esi
    0xffffffff813a18b6 <+6>:	mov    %rsp,%rbp
    0xffffffff813a18b9 <+9>:	callq  0xffffffff813a7120 <memset>
    0xffffffff813a18be <+14>:	pop    %rbp
    0xffffffff813a18bf <+15>:	retq
  End of assembler dump.

  (gdb) disassemble extract_entropy
  [...]
    0xffffffff814a5009 <+313>:	mov    %r12,%rdi
    0xffffffff814a500c <+316>:	mov    $0xa,%esi
    0xffffffff814a5011 <+321>:	callq  0xffffffff813a18b0 <memzero_explicit>
    0xffffffff814a5016 <+326>:	mov    -0x48(%rbp),%rax
  [...]

... but in case in future we might use facilities such as LTO, then
OPTIMIZER_HIDE_VAR() is not sufficient to protect gcc from a possible
eviction of the memset(). We have to use a compiler barrier instead.

Minimal test example when we assume memzero_explicit() would *not* be
a call, but would have been *inlined* instead:

  static inline void memzero_explicit(void *s, size_t count)
  {
    memset(s, 0, count);
    <foo>
  }

  int main(void)
  {
    char buff[20];

    snprintf(buff, sizeof(buff) - 1, "test");
    printf("%s", buff);

    memzero_explicit(buff, sizeof(buff));
    return 0;
  }

With <foo> := OPTIMIZER_HIDE_VAR():

  (gdb) disassemble main
  Dump of assembler code for function main:
  [...]
   0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
   0x0000000000400469 <+41>:	xor    %eax,%eax
   0x000000000040046b <+43>:	add    $0x28,%rsp
   0x000000000040046f <+47>:	retq
  End of assembler dump.

With <foo> := barrier():

  (gdb) disassemble main
  Dump of assembler code for function main:
  [...]
   0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
   0x0000000000400469 <+41>:	movq   $0x0,(%rsp)
   0x0000000000400471 <+49>:	movq   $0x0,0x8(%rsp)
   0x000000000040047a <+58>:	movl   $0x0,0x10(%rsp)
   0x0000000000400482 <+66>:	xor    %eax,%eax
   0x0000000000400484 <+68>:	add    $0x28,%rsp
   0x0000000000400488 <+72>:	retq
  End of assembler dump.

As can be seen, movq, movq, movl are being emitted inlined
via memset().

Reference: http://thread.gmane.org/gmane.linux.kernel.cryptoapi/13764/
Fixes: d4c5efdb97 ("random: add and use memzero_explicit() for clearing data")
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: mancha security <mancha1@zoho.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-20 07:56:12 +11:00
Linus Torvalds
fee5429e02 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 "Here is the crypto update for 3.20:

   - Added 192/256-bit key support to aesni GCM.
   - Added MIPS OCTEON MD5 support.
   - Fixed hwrng starvation and race conditions.
   - Added note that memzero_explicit is not a subsitute for memset.
   - Added user-space interface for crypto_rng.
   - Misc fixes"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (71 commits)
  crypto: tcrypt - do not allocate iv on stack for aead speed tests
  crypto: testmgr - limit IV copy length in aead tests
  crypto: tcrypt - fix buflen reminder calculation
  crypto: testmgr - mark rfc4106(gcm(aes)) as fips_allowed
  crypto: caam - fix resource clean-up on error path for caam_jr_init
  crypto: caam - pair irq map and dispose in the same function
  crypto: ccp - terminate ccp_support array with empty element
  crypto: caam - remove unused local variable
  crypto: caam - remove dead code
  crypto: caam - don't emit ICV check failures to dmesg
  hwrng: virtio - drop extra empty line
  crypto: replace scatterwalk_sg_next with sg_next
  crypto: atmel - Free memory in error path
  crypto: doc - remove colons in comments
  crypto: seqiv - Ensure that IV size is at least 8 bytes
  crypto: cts - Weed out non-CBC algorithms
  MAINTAINERS: add linux-crypto to hw random
  crypto: cts - Remove bogus use of seqiv
  crypto: qat - don't need qat_auth_state struct
  crypto: algif_rng - fix sparse non static symbol warning
  ...
2015-02-14 09:47:01 -08:00
Rasmus Villemoes
8da53d4595 lib/string.c: improve strrchr()
Instead of potentially passing over the string twice in case c is not
found, just keep track of the last occurrence.  According to
bloat-o-meter, this also cuts the generated code by a third (54 vs 36
bytes).  Oh, and we get rid of those 7-space indented lines.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:36 -08:00
Rasmus Villemoes
af3cd13501 lib/string.c: remove strnicmp()
Now that all in-tree users of strnicmp have been converted to
strncasecmp, the wrapper can be removed.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: David Howells <dhowells@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:14 -08:00
Daniel Borkmann
8155330aad lib: memzero_explicit: add comment for its usage
Lets improve the comment to add a note on when to use memzero_explicit()
for those not digging through the git logs. We don't want people to
pollute places with memzero_explicit() where it's not really necessary.

Reference: https://lkml.org/lkml/2015/1/4/190
Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-01-08 21:46:19 +11:00
Linus Torvalds
14d4cc0883 Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random updates from Ted Ts'o:
 "This adds a memzero_explicit() call which is guaranteed not to be
  optimized away by GCC.  This is important when we are wiping
  cryptographically sensitive material"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  crypto: memzero_explicit - make sure to clear out sensitive data
  random: add and use memzero_explicit() for clearing data
2014-10-24 12:33:32 -07:00
Daniel Borkmann
d4c5efdb97 random: add and use memzero_explicit() for clearing data
zatimend has reported that in his environment (3.16/gcc4.8.3/corei7)
memset() calls which clear out sensitive data in extract_{buf,entropy,
entropy_user}() in random driver are being optimized away by gcc.

Add a helper memzero_explicit() (similarly as explicit_bzero() variants)
that can be used in such cases where a variable with sensitive data is
being cleared out in the end. Other use cases might also be in crypto
code. [ I have put this into lib/string.c though, as it's always built-in
and doesn't need any dependencies then. ]

Fixes kernel bugzilla: 82041

Reported-by: zatimend@hotmail.co.uk
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-17 11:37:29 -04:00
Rasmus Villemoes
b0bfb63118 lib: string: Make all calls to strnicmp into calls to strncasecmp
The previous patch made strnicmp into a wrapper for strncasecmp.

This patch makes all in-tree users of strnicmp call strncasecmp
directly, while still making sure that the strnicmp symbol can be used
by out-of-tree modules.  It should be considered a temporary hack until
all in-tree callers have been converted.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:23 +02:00
Rasmus Villemoes
cd514e727b lib/string.c: remove duplicated function
lib/string.c contains two functions, strnicmp and strncasecmp, which do
roughly the same thing, namely compare two strings case-insensitively up
to a given bound.  They have slightly different implementations, but the
only important difference is that strncasecmp doesn't handle len==0
appropriately; it effectively becomes strcasecmp in that case.  strnicmp
correctly says that two strings are always equal in their first 0
characters.

strncasecmp is the POSIX name for this functionality.  So rename the
non-broken function to the standard name.  To minimize the impact on the
rest of the kernel (and since both are exported to modules), make strnicmp
a wrapper for strncasecmp.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:23 +02:00
Linus Torvalds
72d9310460 Make ARCH_HAS_FAST_MULTIPLIER a real config variable
It used to be an ad-hoc hack defined by the x86 version of
<asm/bitops.h> that enabled a couple of library routines to know whether
an integer multiply is faster than repeated shifts and additions.

This just makes it use the real Kconfig system instead, and makes x86
(which was the only architecture that did this) select the option.

NOTE! Even for x86, this really is kind of wrong.  If we cared, we would
probably not enable this for builds optimized for netburst (P4), where
shifts-and-adds are generally faster than multiplies.  This patch does
*not* change that kind of logic, though, it is purely a syntactic change
with no code changes.

This was triggered by the fact that we have other places that really
want to know "do I want to expand multiples by constants by hand or
not", particularly the hash generation code.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-13 11:14:53 -07:00
Dan Carpenter
0046dd9fed lib/string.c: use the name "C-string" in comments
For strncpy() and friends the source string may or may not have an actual
NUL character at the end.  The documentation is confusing in this because
it specifically mentions that you are passing a "NUL-terminated" string.
Wikipedia says that "C-string" is an alternative name we can use instead.

http://en.wikipedia.org/wiki/Null-terminated_string

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Grant Likely
11d200e95f lib: add glibc style strchrnul() variant
The strchrnul() variant helpfully returns a the end of the string
instead of a NULL if the requested character is not found. This can
simplify string parsing code since it doesn't need to expicitly check
for a NULL return. If a valid string pointer is passed in, then a valid
null terminated string will always come back out.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-05-23 11:23:27 +09:00
Andi Kleen
a7330c997d asmlinkage Make __stack_chk_failed and memcmp visible
In LTO symbols implicitely referenced by the compiler need
to be visible. Earlier these symbols were visible implicitely
from being exported, but we disabled implicit visibility fo
 EXPORTs when modules are disabled to improve code size. So
now these symbols have to be marked visible explicitely.

Do this for __stack_chk_fail (with stack protector)
and memcmp.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391845930-28580-10-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-13 18:13:43 -08:00
Linus Torvalds
11bcb32848 Merge tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker:
 "Fix up files in fs/ and lib/ dirs to only use module.h if they really
  need it.

  These are trivial in scope vs the work done previously.  We now have
  things where any few remaining cleanups can be farmed out to arch or
  subsystem maintainers, and I have done so when possible.  What is
  remaining here represents the bits that don't clearly lie within a
  single arch/subsystem boundary, like the fs dir and the lib dir.

  Some duplicate includes arising from overlapping fixes from
  independent subsystem maintainer submissions are also quashed."

Fix up trivial conflicts due to clashes with other include file cleanups
(including some due to the previous bug.h cleanup pull).

* tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  lib: reduce the use of module.h wherever possible
  fs: reduce the use of module.h wherever possible
  includecheck: delete any duplicate instances of module.h
2012-03-24 10:24:31 -07:00
Linus Torvalds
ed2d265d12 Merge tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull <linux/bug.h> cleanup from Paul Gortmaker:
 "The changes shown here are to unify linux's BUG support under the one
  <linux/bug.h> file.  Due to historical reasons, we have some BUG code
  in bug.h and some in kernel.h -- i.e.  the support for BUILD_BUG in
  linux/kernel.h predates the addition of linux/bug.h, but old code in
  kernel.h wasn't moved to bug.h at that time.  As a band-aid, kernel.h
  was including <asm/bug.h> to pseudo link them.

  This has caused confusion[1] and general yuck/WTF[2] reactions.  Here
  is an example that violates the principle of least surprise:

      CC      lib/string.o
      lib/string.c: In function 'strlcat':
      lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
      make[2]: *** [lib/string.o] Error 1
      $
      $ grep linux/bug.h lib/string.c
      #include <linux/bug.h>
      $

  We've included <linux/bug.h> for the BUG infrastructure and yet we
  still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh -
  very confusing for someone who is new to kernel development.

  With the above in mind, the goals of this changeset are:

  1) find and fix any include/*.h files that were relying on the
     implicit presence of BUG code.
  2) find and fix any C files that were consuming kernel.h and hence
     relying on implicitly getting some/all BUG code.
  3) Move the BUG related code living in kernel.h to <linux/bug.h>
  4) remove the asm/bug.h from kernel.h to finally break the chain.

  During development, the order was more like 3-4, build-test, 1-2.  But
  to ensure that git history for bisect doesn't get needless build
  failures introduced, the commits have been reorderd to fix the problem
  areas in advance.

	[1]  https://lkml.org/lkml/2012/1/3/90
	[2]  https://lkml.org/lkml/2012/1/17/414"

Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul
and linux-next.

* tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  kernel.h: doesn't explicitly use bug.h, so don't include it.
  bug: consolidate BUILD_BUG_ON with other bug code
  BUG: headers with BUG/BUG_ON etc. need linux/bug.h
  bug.h: add include of it to various implicit C users
  lib: fix implicit users of kernel.h for TAINT_WARN
  spinlock: macroize assert_spin_locked to avoid bug.h dependency
  x86: relocate get/set debugreg fcns to include/asm/debugreg.
2012-03-24 10:08:39 -07:00
Akinobu Mita
f43804bf5f string: memchr_inv() speed improvements
- Generate a 64-bit pattern more efficiently

memchr_inv needs to generate a 64-bit pattern filled with a target
character.  The operation can be done by more efficient way.

- Don't call the slow check_bytes() if the memory area is 64-bit aligned

memchr_inv compares contiguous 64-bit words with the 64-bit pattern as
much as possible.  The outside of the region is checked by check_bytes()
that scans for each byte.  Unfortunately, the first 64-bit word is
unexpectedly scanned by check_bytes() even if the memory area is aligned
to a 64-bit boundary.

Both changes were originally suggested by Eric Dumazet.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:35 -07:00
Paul Gortmaker
8bc3bcc93a lib: reduce the use of module.h wherever possible
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-07 15:04:04 -05:00
Paul Gortmaker
50af5ead3b bug.h: add include of it to various implicit C users
With bug.h currently living right in linux/kernel.h there
are files that use BUG_ON and friends but are not including
the header explicitly.  Fix them up so we can remove the
presence in kernel.h file.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-29 17:15:08 -05:00
Michael Holzheu
66f6958e69 lib/string.c: fix strim() semantics for strings that have only blanks
Commit 84c95c9acf ("string: on strstrip(), first remove leading spaces
before running over str") improved the performance of the strim()
function.

Unfortunately this changed the semantics of strim() and broke my code.
Before the patch it was possible to use strim() without using the return
value for removing trailing spaces from strings that had either only
blanks or only trailing blanks.

Now this does not work any longer for strings that *only* have blanks.

Before patch: "   " -> ""    (empty string)
After patch:  "   " -> "   " (no change)

I think we should remove your patch to restore the old behavior.

The description (lib/string.c):

 * Note that the first trailing whitespace is replaced with a %NUL-terminator

=> The first trailing whitespace of a string that only has whitespace
   characters is the first whitespace

The patch restores the old strim() semantics.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Andre Goddard Rosa <andre.goddard@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:56 -07:00
Akinobu Mita
798248206b lib/string.c: introduce memchr_inv()
memchr_inv() is mainly used to check whether the whole buffer is filled
with just a specified byte.

The function name and prototype are stolen from logfs and the
implementation is from SLUB.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Joern Engel <joern@logfs.org>
Cc: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:47 -07:00
Jonathan Cameron
d0f1fed29e Add a strtobool function matching semantics of existing in kernel equivalents
This is a rename of the usr_strtobool proposal, which was a renamed,
relocated and fixed version of previous kstrtobool RFC

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-19 16:55:28 +09:30
André Goddard Rosa
d6a2eedfdd lib/string.c: simplify strnstr()
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:35 -08:00
André Goddard Rosa
a11d2b64e1 lib/string.c: simplify stricmp()
Removes 32 bytes on core2 with gcc 4.4.1:
   text    data     bss     dec     hex filename
   3196       0       0    3196     c7c lib/string-BEFORE.o
   3164       0       0    3164     c5c lib/string-AFTER.o

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:35 -08:00
Li Zefan
d5f1fb5335 lib: Introduce strnstr()
It differs strstr() in that it limits the length to be searched
in the first string.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8743.6030805@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:09 -05:00
Randy Dunlap
a6cd13f3c9 lib/string.c: fix kernel-doc warnings
Fix kernel-doc warnings (@arg name) in string.c::skip_spaces().

  Warning(lib/string.c:347): No description found for parameter 'str'
  Warning(lib/string.c:347): Excess function parameter 's' description in 'skip_spaces'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:55 -08:00
KOSAKI Motohiro
ca54cb8c9e Subject: Re: [PATCH] strstrip incorrectly marked __must_check
Recently, We marked strstrip() as must_check.  because it was frequently
misused and it should be checked.  However, we found one exception.
scsi/ipr.c intentionally ignore return value of strstrip.  Because it
wishes to keep the whitespace at the beginning.

Thus we need to keep with and without checked whitespace trim function.
This patch adds a new strim() and changes ipr.c to use it.

[akpm@linux-foundation.org: coding-style fixes]
Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:34 -08:00
André Goddard Rosa
84c95c9acf string: on strstrip(), first remove leading spaces before running over str
... so that strlen() iterates over a smaller string comprising of the
remaining characters only.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
André Goddard Rosa
f653398c86 string: factorize skip_spaces and export it to be generally available
On the following sentence:
    while (*s && isspace(*s))
        s++;

If *s == 0, isspace() evaluates to ((_ctype[*s] & 0x20) != 0), which
evaluates to ((0x08 & 0x20) != 0) which equals to 0 as well.
If *s == 1, we depend on isspace() result anyway. In other words,
"a char equals zero is never a space", so remove this check.

Also, *s != 0 is most common case (non-null string).

Fixed const return as noticed by Jan Engelhardt and James Bottomley.
Fixed unnecessary extra cast on strstrip() as noticed by Jan Engelhardt.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
Linus Torvalds
a414f01ac2 strcmp: fix overflow and possibly signedness error
Doing the strcmp return value as

	signed char __res = *cs - *ct;

is wrong for two reasons.  The subtraction can overflow because __res
doesn't use a type big enough.  Moreover the compared bytes should be
interpreted as unsigned char as specified by POSIX.

The same problem is fixed in strncmp.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-18 17:18:13 -08:00
David Brownell
34990cf702 Add a new sysfs_streq() string comparison function
Add a new sysfs_streq() string comparison function, which ignores
the trailing newlines found in sysfs inputs.  By example:

	sysfs_streq("a", "b")	==> false
	sysfs_streq("a", "a")	==> true
	sysfs_streq("a", "a\n")	==> true
	sysfs_streq("a\n", "a")	==> true

This is intended to simplify parsing of sysfs inputs, letting them
avoid the need to manually strip off newlines from inputs.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01 08:03:59 -07:00