commit d41519a69b upstream.
On sparc, if we have an alloca() like situation, as is the case with
SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack
memory. The result can be that the value is clobbered if a trap
or interrupt arrives at just the right instruction.
It only occurs if the function ends returning a value from that
alloca() area and that value can be placed into the return value
register using a single instruction.
For example, in lib/libcrc32c.c:crc32c() we end up with a return
sequence like:
return %i7+8
lduw [%o5+16], %o0 ! MEM[(u32 *)__shash_desc.1_10 + 16B],
%o5 holds the base of the on-stack area allocated for the shash
descriptor. But the return released the stack frame and the
register window.
So if an intererupt arrives between 'return' and 'lduw', then
the value read at %o5+16 can be corrupted.
Add a data compiler barrier to work around this problem. This is
exactly what the gcc fix will end up doing as well, and it absolutely
should not change the code generated for other cpus (unless gcc
on them has the same bug :-)
With crucial insight from Eric Sandeen.
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iQFHBAABCAAxFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlmoFZkTHGJyb29uaWVA
a2VybmVsLm9yZwAKCRAk1otyXVSH0GD+B/0Tfn9s8kkr42GSv444xzjNsOADb2qc
SAMrtJr+kO2B4nC1SeJrwzkQjhS/GKNG1oj6eI+Qt4czbBskrsDR08evp2srhkFe
2uFII9/avhaSLDLIbexT0iHP5ZSHsGOuUpZMuqlCTl1D2JxUOs7WSI/zIpZgTwJu
0FB7BSB1mUqgT89VBb1zFeDaQ8NuArcbaOPMz7jH8SjeGz6Ez6cqqeRnnHNwwT7q
zfbRGsLORiJncNCFHY7zvDA8FOJNIC9x27zzPpjMXdfV/hjyc03Y6ATkcqxeQS1W
vdEfu247SFS1P2D0/5/L1LhOhFQzqdnRHif+N3PuUOu+/MfKnZemezX1
=tOt4
-----END PGP SIGNATURE-----
Merge tag 'lsk-v4.4-17.08-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
LSK 17.08 v4.4-android
* tag 'lsk-v4.4-17.08-android': (451 commits)
Linux 4.4.83
pinctrl: samsung: Remove bogus irq_[un]mask from resource management
pinctrl: sunxi: add a missing function of A10/A20 pinctrl driver
pnfs/blocklayout: require 64-bit sector_t
iio: adc: vf610_adc: Fix VALT selection value for REFSEL bits
usb:xhci:Add quirk for Certain failing HP keyboard on reset after resume
usb: quirks: Add no-lpm quirk for Moshi USB to Ethernet Adapter
usb: core: unlink urbs from the tail of the endpoint's urb_list
USB: Check for dropped connection before switching to full speed
uag: Add US_FL_IGNORE_RESIDUE for Initio Corporation INIC-3069
iio: light: tsl2563: use correct event code
iio: accel: bmc150: Always restore device to normal mode after suspend-resume
staging:iio:resolver:ad2s1210 fix negative IIO_ANGL_VEL read
USB: hcd: Mark secondary HCD as dead if the primary one died
usb: musb: fix tx fifo flush handling again
USB: serial: pl2303: add new ATEN device id
USB: serial: cp210x: add support for Qivicon USB ZigBee dongle
USB: serial: option: add D-Link DWM-222 device ID
nfs/flexfiles: fix leak of nfs4_ff_ds_version arrays
fuse: initialize the flock flag in fuse_file on allocation
...
Occasionally we have to search for an occurrence of a string in an array
of strings. Make a simple helper for that purpose.
BUG=chromium:622499
TEST=Build image with match_string() enabled
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 commit 56b060814e)
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Change-Id: I6075bb868e3578caa33561c85f4be57f4ea94cc2
Reviewed-on: https://chromium-review.googlesource.com/355210
Commit-Ready: Guenter Roeck <groeck@chromium.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
[ Upstream commit da0510c475 ]
The build of frv allmodconfig was failing with the errors like:
/tmp/cc0JSPc3.s: Assembler messages:
/tmp/cc0JSPc3.s:1839: Error: symbol `.LSLT0' is already defined
/tmp/cc0JSPc3.s:1842: Error: symbol `.LASLTP0' is already defined
/tmp/cc0JSPc3.s:1969: Error: symbol `.LELTP0' is already defined
/tmp/cc0JSPc3.s:1970: Error: symbol `.LELT0' is already defined
Commit 866ced950b ("kbuild: Support split debug info v4") introduced
splitting the debug info and keeping that in a separate file. Somehow,
the frv-linux gcc did not like that and I am guessing that instead of
splitting it started copying. The first report about this is at:
https://lists.01.org/pipermail/kbuild-all/2015-July/010527.html.
I will try and see if this can work with frv and if still fails I will
open a bug report with gcc. But meanwhile this is the easiest option to
solve build failure of frv.
Fixes: 866ced950b ("kbuild: Support split debug info v4")
Link: http://lkml.kernel.org/r/1482062348-5352-1-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iQFHBAABCAAxFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAllwdJoTHGJyb29uaWVA
a2VybmVsLm9yZwAKCRAk1otyXVSH0AkKB/0ZQ0WDrfYw1qbMxq6LswCYC7frwSrF
9KQYZ07bHwR2qZKHOGW50+gOSAW4WOV8VBoAA2mznG9hM4tuONP4OXY2cxwS2B/H
48PoxV+6DYgIIz5ojOcb17e348T/YE0GgaHe08LWIePSZb60SZK2TFW5yzUS8rAV
7uS+OeyZ69C0n6NO8hqdBflXvaWhaL/cFw6s/S7oOcHJ7/gLSmzRkLDuVZJNiU2u
KSujgGAO/Bj2L8TlPfbwTR3Dq1M3uAEs6TNwVgJE2bqOI/u/OJFFkLWI+DGZ5qyu
yHVg3dpMEc6mjR7eYlrkhIzdMsLNX+uEK5TIPH+oLXMflboDxFdWScJw
=a1gE
-----END PGP SIGNATURE-----
Merge tag 'lsk-v4.4-17.07-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
LSK 17.07 v4.4-android
* tag 'lsk-v4.4-17.07-android': (402 commits)
dt/vendor-prefixes: remove redundant vendor
Linux 4.4.77
saa7134: fix warm Medion 7134 EEPROM read
x86/mm/pat: Don't report PAT on CPUs that don't support it
ext4: check return value of kstrtoull correctly in reserved_clusters_store
staging: comedi: fix clean-up of comedi_class in comedi_init()
staging: vt6556: vnt_start Fix missing call to vnt_key_init_table.
tcp: fix tcp_mark_head_lost to check skb len before fragmenting
md: fix super_offset endianness in super_1_rdev_size_change
md: fix incorrect use of lexx_to_cpu in does_sb_need_changing
perf tools: Use readdir() instead of deprecated readdir_r() again
perf tests: Remove wrong semicolon in while loop in CQM test
perf trace: Do not process PERF_RECORD_LOST twice
perf dwarf: Guard !x86_64 definitions under #ifdef else clause
perf pmu: Fix misleadingly indented assignment (whitespace)
perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
perf tools: Remove duplicate const qualifier
perf script: Use readdir() instead of deprecated readdir_r()
perf thread_map: Use readdir() instead of deprecated readdir_r()
perf tools: Use readdir() instead of deprecated readdir_r()
...
Conflicts:
Makefile
drivers/Kconfig
drivers/Makefile
drivers/usb/dwc3/gadget.c
Change-Id: Ib4aae2e34ebbf0d7953c748a33f673acb3e744fc
[ Upstream commit 602d9858f0 ]
Some drivers do depend on page mappings to be page aligned.
Swiotlb already enforces such alignment for mappings greater than page,
extend that to page-sized mappings as well.
Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine
assumes page-aligned mappings.
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a91e0f680b upstream.
When using get_options() it's possible to specify a range of numbers,
like 1-100500. The problem is that it doesn't track array size while
calling internally to get_range() which iterates over the range and
fills the memory with numbers.
Link: http://lkml.kernel.org/r/2613C75C-B04D-4BFF-82A6-12F97BA0F620@gmail.com
Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
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>
commit f5f893c57e upstream.
Under SMAP/PAN/etc, we cannot write directly to userspace memory, so
this rearranges the test bytes to get written through copy_to_user().
Additionally drops the bad copy_from_user() test that would trigger a
memcpy() against userspace on failure.
[arnd: the test module was added in 3.14, and this backported patch
should apply cleanly on all version from 3.14 to 4.10.
The original patch was in 4.11 on top of a context change
I saw the bug triggered with kselftest on a 4.4.y stable kernel]
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* linux-linaro-lsk-v4.4-android: (61 commits)
Linux 4.4.36
scsi: mpt3sas: Unblock device after controller reset
flow_dissect: call init_default_flow_dissectors() earlier
mei: fix return value on disconnection
mei: me: fix place for kaby point device ids.
mei: me: disable driver on SPT SPS firmware
drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on
mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
parisc: Also flush data TLB in flush_icache_page_asm
parisc: Fix race in pci-dma.c
parisc: Fix races in parisc_setup_cache_timing()
NFSv4.x: hide array-bounds warning
apparmor: fix change_hat not finding hat after policy replacement
cfg80211: limit scan results cache size
tile: avoid using clocksource_cyc2ns with absolute cycle count
scsi: mpt3sas: Fix secure erase premature termination
Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y
USB: serial: ftdi_sio: add support for TI CC3200 LaunchPad
USB: serial: cp210x: add ID for the Zone DPMX
usb: chipidea: move the lock initialization to core file
...
commit 62e931fac4 upstream.
gen_pool_alloc_algo() iterates over the chunks of a pool trying to find
a contiguous block of memory that satisfies the allocation request.
The shortcut
if (size > atomic_read(&chunk->avail))
continue;
makes the loop skip over chunks that do not have enough bytes left to
fulfill the request. There are two situations, though, where an
allocation might still fail:
(1) The available memory is not contiguous, i.e. the request cannot
be fulfilled due to external fragmentation.
(2) A race condition. Another thread runs the same code concurrently
and is quicker to grab the available memory.
In those situations, the loop calls pool->algo() to search the entire
chunk, and pool->algo() returns some value that is >= end_bit to
indicate that the search failed. This return value is then assigned to
start_bit. The variables start_bit and end_bit describe the range that
should be searched, and this range should be reset for every chunk that
is searched. Today, the code fails to reset start_bit to 0. As a
result, prefixes of subsequent chunks are ignored. Memory allocations
might fail even though there is plenty of room left in these prefixes of
those other chunks.
Fixes: 7f184275aa ("lib, Make gen_pool memory allocator lockless")
Link: http://lkml.kernel.org/r/1477420604-28918-1-git-send-email-danielmentz@google.com
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Will Deacon <will.deacon@arm.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>
* linux-linaro-lsk-v4.4-android: (1362 commits)
Linux 4.4.30
Revert "fix minor infoleak in get_user_ex()"
Revert "x86/mm: Expand the exception table logic to allow new handling options"
Linux 4.4.29
ARM: pxa: pxa_cplds: fix interrupt handling
powerpc/nvram: Fix an incorrect partition merge
mpt3sas: Don't spam logs if logging level is 0
perf symbols: Fixup symbol sizes before picking best ones
perf symbols: Check symbol_conf.allow_aliases for kallsyms loading too
perf hists browser: Fix event group display
clk: divider: Fix clk_divider_round_rate() to use clk_readl()
clk: qoriq: fix a register offset error
s390/con3270: fix insufficient space padding
s390/con3270: fix use of uninitialised data
s390/cio: fix accidental interrupt enabling during resume
x86/mm: Expand the exception table logic to allow new handling options
dmaengine: ipu: remove bogus NO_IRQ reference
power: bq24257: Fix use of uninitialized pointer bq->charger
staging: r8188eu: Fix scheduling while atomic splat
ASoC: dapm: Fix kcontrol creation for output driver widget
...
commit a81a5a17d4 upstream.
Add support for "on" and "off" when converting to boolean.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Amitkumar Karwar <akarwar@marvell.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nishant Sarmukadam <nishants@marvell.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steve French <sfrench@samba.org>
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>
commit ef95159907 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>
The strncpy_from_user() accessor is effectively a copy_from_user()
specialised to copy strings, terminating early at a NUL byte if possible.
In other respects it is identical, and can be used to copy an arbitrarily
large buffer from userspace into the kernel. Conceptually, it exposes a
similar attack surface.
As with copy_from_user(), we check the destination range when the kernel
is built with KASAN, but unlike copy_from_user() we do not check the
destination buffer when using HARDENED_USERCOPY. As strncpy_from_user()
calls get_user() in a loop, we must call check_object_size() explicitly.
This patch adds this instrumentation to strncpy_from_user(), per the same
rationale as with the regular copy_from_user(). In the absence of
hardened usercopy this will have no impact as the instrumentation expands
to an empty static inline function.
Link: http://lkml.kernel.org/r/1472221903-31181-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 31374226
Change-Id: I898e4e9f19307e37a9be497cb1a0d7f1e3911661
(cherry picked from commit bf90e56e46)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
commit d4690f1e1c upstream.
... by turning it into what used to be multipages counterpart
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When I initially added the unsafe_[get|put]_user() helpers in commit
5b24a7a2aa ("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>
(cherry picked from commit 1bd4403d86)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
in fs/proc/task_mmu.c:
looks like vma_get_anon_name() want have a name for anonymous
vma when there is no name used in vma. commit: 586278d78b
The name show is after any other names, so it maybe covered.
but anyway, it just a show here.
commit f2d1362ff7 upstream.
Currently, if the number of leading zeros is greater than fits into a
complete limb, mpi_write_sgl() skips them by iterating over them limb-wise.
However, it fails to adjust its internal leading zeros tracking variable,
lzeros, accordingly: it does a
p -= sizeof(alimb);
continue;
which should really have been a
lzeros -= sizeof(alimb);
continue;
Since lzeros never decreases if its initial value >= sizeof(alimb), nothing
gets copied by mpi_write_sgl() in that case.
Instead of skipping the high order zero limbs within the loop as shown
above, fix the issue by adjusting the copying loop's bounds.
Fixes: 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 23c8a812dc ]
This fixes CVE-2016-0758.
In the ASN.1 decoder, when the length field of an ASN.1 value is extracted,
it isn't validated against the remaining amount of data before being added
to the cursor. With a sufficiently large size indicated, the check:
datalen - dp < 2
may then fail due to integer overflow.
Fix this by checking the length indicated against the amount of remaining
data in both places a definite length is determined.
Whilst we're at it, make the following changes:
(1) Check the maximum size of extended length does not exceed the capacity
of the variable it's being stored in (len) rather than the type that
variable is assumed to be (size_t).
(2) Compare the EOC tag to the symbolic constant ASN1_EOC rather than the
integer 0.
(3) To reduce confusion, move the initialisation of len outside of:
for (len = 0; n > 0; n--) {
since it doesn't have anything to do with the loop counter n.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This may be useful for detecting and debugging RT throttling issues.
Change-Id: I5807a897d11997d76421c1fcaa2918aad988c6c9
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
[rameezmustafa@codeaurora.org]: Port to msm-3.18]
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
[jstultz: forwardported to 4.4]
Signed-off-by: John Stultz <john.stultz@linaro.org>
When I initially added the unsafe_[get|put]_user() helpers in commit
5b24a7a2aa ("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 1bd4403d86)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
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>
(cherry picked from commit 9fd4470ff4)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Android healthd try to listen power_supply subsystem uevent,
but which will block system from suspend on big.LITTLE system
because thermal_cooling_device_unregister will called when
cpufreq_exit. So ignore this uevent when suspend.
Change-Id: I35948498916560d5ec75fe561c9e9d588663ad22
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>