Not all supported chips support the entire I2C address range.
Only accept specific chips at the addresses supported by that chip.
Check for invalid values in conversion rate and status registers.
Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jean Delvare <jdelvare@suse.de>
Guenter Roeck [Mon, 30 Jun 2014 14:34:30 +0000 (07:34 -0700)]
hwmon: (w83791d) Fix smatch warning
smatch complains as follows when checking w83791d.c.
drivers/hwmon/w83791d.c:996 store_temp23() warn:
'32768' 32768 can't fit into 32767 'data->temp_add[nr][index]'
Fix by using DIV_ROUND_CLOSEST and clamp_val to convert the values.
While we are at it, modify other macros as well for consistency and
to make the code easier to understand.
Guenter Roeck [Wed, 25 Jun 2014 15:08:35 +0000 (08:08 -0700)]
hwmon: (lm63) Fix smatch warnings
smatch complains as follows when checking lm63.c.
drivers/hwmon/lm63.c:594 set_temp11() warn:
'65504' 65504 can't fit into 32767 'data->temp11[nr]'
drivers/hwmon/lm63.c:596 set_temp11() warn:
'32768' 32768 can't fit into 32767 'data->temp11[nr]'
Fix by using DIV_ROUND_CLOSEST and clamp_val to convert the values.
While we are at it, modify other macros as well for consistency and
to make the code easier to understand.
Axel Lin [Tue, 17 Jun 2014 15:12:08 +0000 (23:12 +0800)]
hwmon: (wm8350) Convert to devm_hwmon_device_register_with_groups
Use ATTRIBUTE_GROUPS macro and devm_hwmon_device_register_with_groups() to
simplify the code a bit.
Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Axel Lin [Tue, 17 Jun 2014 15:10:55 +0000 (23:10 +0800)]
hwmon: (wm831x) Convert to devm_hwmon_device_register_with_groups
Use ATTRIBUTE_GROUPS macro and devm_hwmon_device_register_with_groups() to
simplify the code a bit.
Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Axel Lin [Thu, 31 Jul 2014 14:58:04 +0000 (22:58 +0800)]
hwmon: (lm77) Prevent overflow problem when writing large limits
On platforms with sizeof(int) < sizeof(long), writing a temperature
limit larger than MAXINT will result in unpredictable limit values
written to the chip.
Clamp the input values to the supported limits first to fix the problem.
For set_temp_hyst:
As Guenter pointed out that the temperature is read as unsigned and stored in
an unsigned long. This is wrong; nothing in the datasheet suggests that the
value (the absolute temperature) must be positive.
So change it to signed.
Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Axel Lin [Thu, 31 Jul 2014 01:43:19 +0000 (09:43 +0800)]
hwmon: (amc6821) Fix possible race condition bug
Ensure mutex lock protects the read-modify-write period to prevent possible
race condition bug.
In additional, update data->valid should also be protected by the mutex lock.
Signed-off-by: Axel Lin <axel.lin@ingics.com> Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (lm78) Fix overflow problems seen when writing large temperature limits
On platforms with sizeof(int) < sizeof(long), writing a temperature
limit larger than MAXINT will result in unpredictable limit values
written to the chip. Avoid auto-conversion from long to int to fix
the problem.
Cc: Axel Lin <axel.lin@ingics.com> Cc: stable@vger.kernel.org Reviewed-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (lm85) Fix various errors on attribute writes
Temperature limit register writes did not account for negative numbers.
As a result, writing -127000 resulted in -126000 written into the
temperature limit register. This problem affected temp[1-3]_min,
temp[1-3]_max, temp[1-3]_auto_temp_crit, and temp[1-3]_auto_temp_min.
When writing pwm[1-3]_freq, a long variable was auto-converted into an int
without range check. Wiring values larger than MAXINT resulted in unexpected
register values.
When writing temp[1-3]_auto_temp_max, an unsigned long variable was
auto-converted into an int without range check. Writing values larger than
MAXINT resulted in unexpected register values.
vrm is an u8, so the written value needs to be limited to [0, 255].
Cc: Axel Lin <axel.lin@ingics.com> Cc: stable@vger.kernel.org Reviewed-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"A bunch of fixes for perf and kprobes:
- revert a commit that caused a perf group regression
- silence dmesg spam
- fix kprobe probing errors on ia64 and ppc64
- filter kprobe faults from userspace
- lockdep fix for perf exit path
- prevent perf #GP in KVM guest
- correct perf event and filters"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64
kprobes/x86: Don't try to resolve kprobe faults from userspace
perf/x86/intel: Avoid spamming kernel log for BTS buffer failure
perf/x86/intel: Protect LBR and extra_regs against KVM lying
perf: Fix lockdep warning on process exit
perf/x86/intel/uncore: Fix SNB-EP/IVT Cbox filter mappings
perf/x86/intel: Use proper dTLB-load-misses event on IvyBridge
perf: Revert ("perf: Always destroy groups on exit")
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Peter Anvin:
"A couple of crash fixes, plus a fix that on 32 bits would cause a
missing -ENOSYS for nonexistent system calls"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, cpu: Fix cache topology for early P4-SMT
x86_32, entry: Store badsys error code in %eax
x86, MCE: Robustify mcheck_init_device
Merge tag 'firewire-fix-vt6315' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394
Pull firewire regression fix from Stefan Richter:
"IEEE 1394 (FireWire) subsystem fix: MSI don't work on VIA PCIe
controllers with some isochronous workloads (regression since
v3.16-rc1)"
* tag 'firewire-fix-vt6315' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
firewire: ohci: disable MSI for VIA VT6315 again
Fix gcc-4.9.0 miscompilation of load_balance() in scheduler
Michel Dänzer and a couple of other people reported inexplicable random
oopses in the scheduler, and the cause turns out to be gcc mis-compiling
the load_balance() function when debugging is enabled. The gcc bug
apparently goes back to gcc-4.5, but slight optimization changes means
that it now showed up as a problem in 4.9.0 and 4.9.1.
The instruction scheduling problem causes gcc to schedule a spill
operation to before the stack frame has been created, which in turn can
corrupt the spilled value if an interrupt comes in. There may be other
effects of this bug too, but that's the code generation problem seen in
Michel's case.
This is fixed in current gcc HEAD, but the workaround as suggested by
Markus Trippelsdorf is pretty simple: use -fno-var-tracking-assignments
when compiling the kernel, which disables the gcc code that causes the
problem. This can result in slightly worse debug information for
variable accesses, but that is infinitely preferable to actual code
generation problems.
Doing this unconditionally (not just for CONFIG_DEBUG_INFO) also allows
non-debug builds to verify that the debug build would be identical: we
can do
export GCC_COMPARE_DEBUG=1
to make gcc internally verify that the result of the build is
independent of the "-g" flag (it will make the compiler build everything
twice, toggling the debug flag, and compare the results).
Without the "-fno-var-tracking-assignments" option, the build would fail
(even with 4.8.3 that didn't show the actual stack frame bug) with a gcc
compare failure.
970 if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
971 PF_MEMALLOC))
I did not respond at the time, because a glance at the PageDirty block
in shrink_page_list() quickly shows that this is impossible: we don't do
writeback on file pages (other than tmpfs) from direct reclaim nowadays.
Dave was hallucinating, but it would have been disrespectful to say so.
However, my own /var/log/messages now shows similar complaints
WARNING: CPU: 1 PID: 28814 at fs/ext4/inode.c:1881 ext4_writepage+0xa7/0x38b()
WARNING: CPU: 0 PID: 27347 at fs/ext4/inode.c:1764 ext4_writepage+0xa7/0x38b()
from stressing some mmotm trees during July.
Could a dirty xfs or ext4 file page somehow get marked PageSwapBacked,
so fail shrink_page_list()'s page_is_file_cache() test, and so proceed
to mapping->a_ops->writepage()?
Yes, 3.16-rc1's commit 68711a746345 ("mm, migration: add destination
page freeing callback") has provided such a way to compaction: if
migrating a SwapBacked page fails, its newpage may be put back on the
list for later use with PageSwapBacked still set, and nothing will clear
it.
Whether that can do anything worse than issue WARN_ON_ONCEs, and get
some statistics wrong, is unclear: easier to fix than to think through
the consequences.
Fixing it here, before the put_new_page(), addresses the bug directly,
but is probably the worst place to fix it. Page migration is doing too
many parts of the job on too many levels: fixing it in
move_to_new_page() to complement its SetPageSwapBacked would be
preferable, except why is it (and newpage->mapping and newpage->index)
done there, rather than down in migrate_page_move_mapping(), once we are
sure of success? Not a cleanup to get into right now, especially not
with memcg cleanups coming in 3.17.
Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"This is radeon and intel fixes, and is a small bit larger than I'm
guessing you'd like it to be.
- i915: fixes 32-bit highmem i915 blank screen, semaphore hang and
runtime pm fix
- radeon: gpuvm stability fix for hangs since 3.15, and hang/reboot
regression on TN/RL devices,
The only slightly controversial one is the change to use GB for the
vm_size, which I'm letting through as its a new interface we defined
in this merge window, and I'd prefer to have the released kernel have
the final interface rather than changing it later"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon: fix cut and paste issue for hawaii.
drm/radeon: fix irq ring buffer overflow handling
drm/i915: Simplify i915_gem_release_all_mmaps()
drm/radeon: fix error handling in radeon_vm_bo_set_addr
drm/i915: fix freeze with blank screen booting highmem
drm/i915: Reorder the semaphore deadlock check, again
drm/radeon/TN: only enable bapm on MSI systems
drm/radeon: fix VM IB handling
drm/radeon: fix handling of radeon_vm_bo_rmv v3
drm/radeon: let's use GB for vm_size (v2)
Merge tag 'sound-3.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Here contains only the fixes for the new FireWire bebob driver. All
fairly trivial and local fixes, so safe to apply"
* tag 'sound-3.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: bebob: Correction for return value of special_clk_ctl_put() in error
ALSA: bebob: Correction for return value of .put callback
ALSA: bebob: Use different labels for digital input/output
ALSA: bebob: Fix a missing to unlock mutex in error handling case
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fix from Guenter Roeck:
"Fixes to temperature limit and vrm write operations in smsc47m192
driver"
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (smsc47m192) Fix temperature limit and vrm write operations
Randy Dunlap [Sat, 26 Jul 2014 00:07:47 +0000 (17:07 -0700)]
parport: fix menu breakage
Do not split the PARPORT-related symbols with the new kconfig
symbol ARCH_MIGHT_HAVE_PC_PARPORT. The split was causing incorrect
display of these symbols -- they were not being displayed together
as they should be.
Fixes: d90c3eb31535 "Kconfig cleanup (PARPORT_PC dependencies)" Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Mark Salter <msalter@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org # for 3.13, 3.14, 3.15 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'blackfin-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux
Pull blackfin fixes from Steven Miao:
"smc nor flash PM fix, pinctrl group fix, update defconfig, and build
fixes"
* tag 'blackfin-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux:
blackfin: vmlinux.lds.S: reserve 32 bytes space at the end of data section for XIP kernel
defconfig: BF609: update spi config name
irq: blackfin sec: drop duplicated sec priority set
blackfin: bind different groups of one pinmux function to different state name
blackfin: fix some bf5xx boards build for missing <linux/gpio.h>
pm: bf609: cleanup smc nor flash
Merge branch 'parisc-3.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
"We have two trivial patches in here. One removes the SA_RESTORER
#define since on parisc we don't have the sa_restorer field in struct
sigaction, the other patch removes an unnecessary memset().
The SA_RESTORER removal patch is scheduled for stable trees, since
without it some userspace apps don't build"
* 'parisc-3.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Eliminate memset after alloc_bootmem_pages
parisc: Remove SA_RESTORER define
went in. What this patch did was, among others, check the return value
of misc_register and exit early if it encountered an error. Original
code sloppily didn't do that.
However,
cef12ee52b05 ("xen/mce: Add mcelog support for Xen platform")
made it so that xen's init routine xen_late_init_mcelog runs first. This
was needed for the xen mcelog device which is supposed to be independent
from the baremetal one.
Initially it was reported that misc_register() fails often on xen and
that's why it needed fixing. However, it is *supposed* to fail by
design, when running in dom0 so that the xen mcelog device file gets
registered first.
And *then* you need the notifier *not* unregistered on the error path so
that the timer does get deleted properly in the CPU hotplug notifier.
Btw, this fix is needed also on baremetal in the unlikely event that
misc_register(&mce_chrdev_device) fails there too.
I was unsure whether to rush it in now and decided to delay it to 3.17.
However, xen people wanted it promoted as it breaks xen when doing cpu
hotplug there. So, after a bit of simmering in tip/master for initial
smoke testing, let's move it to 3.16. It fixes a semi-regression which
got introduced in 3.16 so no need for stable tagging.
tip/x86/ras contains that exact same commit but we can't remove it
there as it is not the last one. It won't cause any merge issues, as I
confirmed locally but I should state here the special situation of this
one fix explicitly anyway.
Thanks.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Dave Airlie [Thu, 24 Jul 2014 23:16:28 +0000 (09:16 +1000)]
Merge tag 'drm-intel-fixes-2014-07-24' of git://anongit.freedesktop.org/drm-intel into drm-fixes
This time in time! Just 32bit-pae fix from Hugh, semaphores fun from Chris
and a fix for runtime pm cherry-picked from next.
Paulo is still working on a fix for runtime pm when X does cursor fun when
the display is off, but that one isn't ready yet.
* tag 'drm-intel-fixes-2014-07-24' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Simplify i915_gem_release_all_mmaps()
drm/i915: fix freeze with blank screen booting highmem
drm/i915: Reorder the semaphore deadlock check, again
The sa_restorer field in struct sigaction is obsolete and no longer in
the parisc implementation. However, the core code assumes the field is
present if SA_RESTORER is defined. So, the define needs to be removed.
Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: <stable@vger.kernel.org> Signed-off-by: Helge Deller <deller@gmx.de>
hwmon: (smsc47m192) Fix temperature limit and vrm write operations
Temperature limit clamps are applied after converting the temperature
from milli-degrees C to degrees C, so either the clamp limit needs
to be specified in degrees C, not milli-degrees C, or clamping must
happen before converting to degrees C. Use the latter method to avoid
overflows.
vrm is an u8, so the written value needs to be limited to [0, 255].
Cc: Axel Lin <axel.lin@ingics.com> Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jean Delvare <jdelvare@suse.de>
In this case mountpoint_last() gets an extra refcount on path->mnt
Signed-off-by: Vasily Averin <vvs@openvz.org> Acked-by: Ian Kent <raven@themaw.net> Acked-by: Jeff Layton <jlayton@primarydata.com> Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig <hch@lst.de>
direct-io: fix uninitialized warning in do_direct_IO()
The following warnings:
fs/direct-io.c: In function ‘__blockdev_direct_IO’:
fs/direct-io.c:1011:12: warning: ‘to’ may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/direct-io.c:913:16: note: ‘to’ was declared here
fs/direct-io.c:1011:12: warning: ‘from’ may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/direct-io.c:913:10: note: ‘from’ was declared here
are false positive because dio_get_page() either fails, or sets both
'from' and 'to'.
Paul Bolle said ...
Maybe it's better to move initializing "to" and "from" out of
dio_get_page(). That _might_ make it easier for both the the reader and
the compiler to understand what's going on. Something like this:
Christoph Hellwig said ...
The fix of moving the code definitively looks nicer, while I think
uninitialized_var is horrible wart that won't get anywhere near my code.
Boaz Harrosh: I agree with Christoph and Paul
Signed-off-by: Boaz Harrosh <boaz@plexistor.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fix from Catalin Marinas:
"Fix arm64 regression introduced by limiting the CMA buffer to ZONE_DMA
on platforms where RAM starts above 4GB (and ZONE_DMA becoming 0)"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: Create non-empty ZONE_DMA when DRAM starts above 4GB
Merge tag 'xtensa-next-20140721' of git://github.com/czankel/xtensa-linux
Pull Xtensa fixes from Chris Zankel:
- resolve FIXMEs in double exception handler for window overflow. This
fix makes native building of linux on xtensa host possible;
- fix sysmem region removal issue introduced in 3.15.
* tag 'xtensa-next-20140721' of git://github.com/czankel/xtensa-linux:
xtensa: fix sysmem reservation at the end of existing block
xtensa: add fixup for double exception raised in window overflow
Merge tag 'pinctrl-v3.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control fixes from Linus Walleij:
"Here are three pin control fixes for the v3.16 series. Sorry that
some of these arrive late, the summer heat in Sweden makes me slow.
- an IRQ handling fix for the STi driver, also for stable
- another IRQ fix for the RCAR GPIO driver
- a MAINTAINERS entry"
* tag 'pinctrl-v3.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
gpio: rcar: Add support for DT IRQ flags
MAINTAINERS: Add entry for the Renesas pin controller driver
pinctrl: st: Fix irqmux handler
Merge branch 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata regression fix from Tejun Heo:
"The last libata/for-3.16-fixes pull contained a regression introduced
by 1871ee134b73 ("libata: support the ata host which implements a
queue depth less than 32") which in turn was a fix for a regression
introduced earlier while changing queue tag order to accomodate hard
drives which perform poorly if tags are not allocated in circular
order (ugh...).
The regression happens only for SAS controllers making use of libata
to serve ATA devices. They don't fill an ata_host field which is used
by the new tag allocation function leading to NULL dereference.
This patch adds a new intermediate field ata_host->n_tags which is
initialized for both SAS and !SAS cases to fix the issue"
* 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
libata: introduce ata_host->n_tags to avoid oops on SAS controllers
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc fixes from Ben Herrenschmidt:
"Here is a handful of powerpc fixes for 3.16. They are all pretty
simple and self contained and should still make this release"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: use _GLOBAL_TOC for memmove
powerpc/pseries: dynamically added OF nodes need to call of_node_init
powerpc: subpage_protect: Increase the array size to take care of 64TB
powerpc: Fix bugs in emulate_step()
powerpc: Disable doorbells on Power8 DD1.x
Merge tag 'urgent-slab-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull slab fix from Mike Snitzer:
"This fixes the broken duplicate slab name check in
kmem_cache_sanity_check() that has been repeatedly reported (as
recently as today against Fedora rawhide).
Pekka seemed to have it staged for a late 3.15-rc in his 'slab/urgent'
branch but never sent a pull request, see:
https://lkml.org/lkml/2014/5/23/648"
* tag 'urgent-slab-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
slab_common: fix the check for duplicate slab names
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: hugetlb: fix copy_hugetlb_page_range()
simple_xattr: permit 0-size extended attributes
mm/fs: fix pessimization in hole-punching pagecache
shmem: fix splicing from a hole while it's punched
shmem: fix faulting into a hole, not taking i_mutex
mm: do not call do_fault_around for non-linear fault
sh: also try passing -m4-nofpu for SH2A builds
zram: avoid lockdep splat by revalidate_disk
mm/rmap.c: fix pgoff calculation to handle hugepage correctly
coredump: fix the setting of PF_DUMPCORE
Commit 4a705fef9862 ("hugetlb: fix copy_hugetlb_page_range() to handle
migration/hwpoisoned entry") changed the order of
huge_ptep_set_wrprotect() and huge_ptep_get(), which leads to breakage
in some workloads like hugepage-backed heap allocation via libhugetlbfs.
This patch fixes it.
Fixes 4a705fef9862 ("hugetlb: fix copy_hugetlb_page_range() to handle
migration/hwpoisoned entry"), so is applicable to -stable kernels which
include it.
If a filesystem uses simple_xattr to support user extended attributes,
LTP setxattr01 and xfstests generic/062 fail with "Cannot allocate
memory": simple_xattr_alloc()'s wrap-around test mistakenly excludes
values of zero size. Fix that off-by-one (but apparently no filesystem
needs them yet).
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: Aristeu Rozanski <aris@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/fs: fix pessimization in hole-punching pagecache
I wanted to revert my v3.1 commit d0823576bf4b ("mm: pincer in
truncate_inode_pages_range"), to keep truncate_inode_pages_range() in
synch with shmem_undo_range(); but have stepped back - a change to
hole-punching in truncate_inode_pages_range() is a change to
hole-punching in every filesystem (except tmpfs) that supports it.
If there's a logical proof why no filesystem can depend for its own
correctness on the pincer guarantee in truncate_inode_pages_range() - an
instant when the entire hole is removed from pagecache - then let's
revisit later. But the evidence is that only tmpfs suffered from the
livelock, and we have no intention of extending hole-punch to ramfs. So
for now just add a few comments (to match or differ from those in
shmem_undo_range()), and fix one silliness noticed in d0823576bf4b...
Its "index == start" addition to the hole-punch termination test was
incomplete: it opened a way for the end condition to be missed, and the
loop go on looking through the radix_tree, all the way to end of file.
Fix that pessimization by resetting index when detected in inner loop.
Note that it's actually hard to hit this case, without the obsessive
concurrent faulting that trinity does: normally all pages are removed in
the initial trylock_page() pass, and this loop finds nothing to do. I
had to "#if 0" out the initial pass to reproduce bug and test fix.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem: fix splicing from a hole while it's punched
shmem_fault() is the actual culprit in trinity's hole-punch starvation,
and the most significant cause of such problems: since a page faulted is
one that then appears page_mapped(), needing unmap_mapping_range() and
i_mmap_mutex to be unmapped again.
But it is not the only way in which a page can be brought into a hole in
the radix_tree while that hole is being punched; and Vlastimil's testing
implies that if enough other processors are busy filling in the hole,
then shmem_undo_range() can be kept from completing indefinitely.
shmem_file_splice_read() is the main other user of SGP_CACHE, which can
instantiate shmem pagecache pages in the read-only case (without holding
i_mutex, so perhaps concurrently with a hole-punch). Probably it's
silly not to use SGP_READ already (using the ZERO_PAGE for holes): which
ought to be safe, but might bring surprises - not a change to be rushed.
shmem_read_mapping_page_gfp() is an internal interface used by
drivers/gpu/drm GEM (and next by uprobes): it should be okay. And
shmem_file_read_iter() uses the SGP_DIRTY variant of SGP_CACHE, when
called internally by the kernel (perhaps for a stacking filesystem,
which might rely on holes to be reserved): it's unclear whether it could
be provoked to keep hole-punch busy or not.
We could apply the same umbrella as now used in shmem_fault() to
shmem_file_splice_read() and the others; but it looks ugly, and use over
a range raises questions - should it actually be per page? can these get
starved themselves?
The origin of this part of the problem is my v3.1 commit d0823576bf4b
("mm: pincer in truncate_inode_pages_range"), once it was duplicated
into shmem.c. It seemed like a nice idea at the time, to ensure
(barring RCU lookup fuzziness) that there's an instant when the entire
hole is empty; but the indefinitely repeated scans to ensure that make
it vulnerable.
Revert that "enhancement" to hole-punch from shmem_undo_range(), but
retain the unproblematic rescanning when it's truncating; add a couple
of comments there.
Remove the "indices[0] >= end" test: that is now handled satisfactorily
by the inner loop, and mem_cgroup_uncharge_start()/end() are too light
to be worth avoiding here.
But if we do not always loop indefinitely, we do need to handle the case
of swap swizzled back to page before shmem_free_swap() gets it: add a
retry for that case, as suggested by Konstantin Khlebnikov; and for the
case of page swizzled back to swap, as suggested by Johannes Weiner.
Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: <stable@vger.kernel.org> [3.1+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem: fix faulting into a hole, not taking i_mutex
Commit f00cdc6df7d7 ("shmem: fix faulting into a hole while it's
punched") was buggy: Sasha sent a lockdep report to remind us that
grabbing i_mutex in the fault path is a no-no (write syscall may already
hold i_mutex while faulting user buffer).
We tried a completely different approach (see following patch) but that
proved inadequate: good enough for a rational workload, but not good
enough against trinity - which forks off so many mappings of the object
that contention on i_mmap_mutex while hole-puncher holds i_mutex builds
into serious starvation when concurrent faults force the puncher to fall
back to single-page unmap_mapping_range() searches of the i_mmap tree.
So return to the original umbrella approach, but keep away from i_mutex
this time. We really don't want to bloat every shmem inode with a new
mutex or completion, just to protect this unlikely case from trinity.
So extend the original with wait_queue_head on stack at the hole-punch
end, and wait_queue item on the stack at the fault end.
This involves further use of i_lock to guard against the races: lockdep
has been happy so far, and I see fs/inode.c:unlock_new_inode() holds
i_lock around wake_up_bit(), which is comparable to what we do here.
i_lock is more convenient, but we could switch to shmem's info->lock.
This issue has been tagged with CVE-2014-4171, which will require commit f00cdc6df7d7 and this and the following patch to be backported: we
suggest to 3.1+, though in fact the trinity forkbomb effect might go
back as far as 2.6.16, when madvise(,,MADV_REMOVE) came in - or might
not, since much has changed, with i_mmap_mutex a spinlock before 3.0.
Anyone running trinity on 3.0 and earlier? I don't think we need care.
Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: <stable@vger.kernel.org> [3.1+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: do not call do_fault_around for non-linear fault
Ingo Korb reported that "repeated mapping of the same file on tmpfs
using remap_file_pages sometimes triggers a BUG at mm/filemap.c:202 when
the process exits".
He bisected the bug to d7c1755179b8 ("mm: implement ->map_pages for
shmem/tmpfs"), although the bug was actually added by commit 8c6e50b0290c ("mm: introduce vm_ops->map_pages()").
The problem is caused by calling do_fault_around for a _non-linear_
fault. In this case pgoff is shifted and might become negative during
calculation.
Faulting around non-linear page-fault makes no sense and breaks the
logic in do_fault_around because pgoff is shifted.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reported-by: Ingo Korb <ingo.korb@tu-dortmund.de> Tested-by: Ingo Korb <ingo.korb@tu-dortmund.de> Cc: Hugh Dickins <hughd@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dave Jones <davej@redhat.com> Cc: Ning Qu <quning@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [3.15.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When compiling a SH2A kernel (e.g. se7206_defconfig or rsk7203_defconfig)
using sh4-linux-gcc, linking fails with:
net/built-in.o: In function `__sk_run_filter':
net/core/filter.c:566: undefined reference to `__fpscr_values'
net/core/filter.c:269: undefined reference to `__fpscr_values'
...
net/built-in.o:net/core/filter.c:580: more undefined references to `__fpscr_values' follow
This happens because sh4-linux-gcc doesn't support the "-m2a-nofpu",
which is thus filtered out by "$(call cc-option, ...)".
As compiling using sh4-linux-gcc is useful for compile coverage, also
try passing "-m4-nofpu" (which is presumably filtered out when using a
real sh2a-linux toolchain) to disable the generation of FPU instructions
and references to __fpscr_values[].
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Tony Breeds <tony@bakeyournoodle.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Magnus Damm <magnus.damm@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 23 Jul 2014 21:00:04 +0000 (14:00 -0700)]
zram: avoid lockdep splat by revalidate_disk
Sasha reported lockdep warning [1] introduced by [2].
It could be fixed by doing disk revalidation out of the init_lock. It's
okay because disk capacity change is protected by init_lock so that
revalidate_disk always sees up-to-date value so there is no race.
[1] https://lkml.org/lkml/2014/7/3/735
[2] zram: revalidate disk after capacity change
Fixes 2e32baea46ce ("zram: revalidate disk after capacity change").
projects / linux-beck.git / log