The commit c404e0dc (Btrfs: fix use-after-free in the finishing
procedure of the device replace) fixed a use-after-free problem
which happened when removing the source device at the end of device
replace, but at that time, btrfs didn't support device replace
on raid56, so we didn't fix the problem on the raid56 profile.
Currently, we implemented device replace for raid56, so we need
kick that problem out before we enable that function for raid56.
The fix method is very simple, we just increase the bio per-cpu
counter before we submit a raid56 io, and decrease the counter
when the raid56 io ends.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This function reused the code of parity scrub, and we just write
the right parity or corrected parity into the target device before
the parity scrub end.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The implementation is simple:
- In order to avoid changing the code logic of btrfs_map_bio and
RAID56, we add the stripes of the replace target devices at the
end of the stripe array in btrfs bio, and we sort those target
device stripes in the array. And we keep the number of the target
device stripes in the btrfs bio.
- Except write operation on RAID56, all the other operation don't
take the target device stripes into account.
- When we do write operation, we read the data from the common devices
and calculate the parity. Then write the dirty data and new parity
out, at this time, we will find the relative replace target stripes
and wirte the relative data into it.
Note: The function that copying old data on the source device to
the target device was implemented in the past, it is similar to
the other RAID type.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The implementation is:
- Read and check all the data with checksum in the same stripe.
All the data which has checksum is COW data, and we are sure
that it is not changed though we don't lock the stripe. because
the space of that data just can be reclaimed after the current
transction is committed, and then the fs can use it to store the
other data, but when doing scrub, we hold the current transaction,
that is that data can not be recovered, it is safe that read and check
it out of the stripe lock.
- Lock the stripe
- Read out all the data without checksum and parity
The data without checksum and the parity may be changed if we don't
lock the stripe, so we need read it in the stripe lock context.
- Check the parity
- Re-calculate the new parity and write back it if the old parity
is not right
- Unlock the stripe
If we can not read out the data or the data we read is corrupted,
we will try to repair it. If the repair fails. we will mark the
horizontal sub-stripe(pages on the same horizontal) as corrupted
sub-stripe, and we will skip the parity check and repair of that
horizontal sub-stripe.
And in order to skip the horizontal sub-stripe that has no data, we
introduce a bitmap. If there is some data on the horizontal sub-stripe,
we will the relative bit to 1, and when we check and repair the
parity, we will skip those horizontal sub-stripes that the relative
bits is 0.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
We will introduce new operation type later, if we still use integer
variant as bool variant to record the operation type, we would add new
variant and increase the size of raid bio structure. It is not good,
by this patch, we define different number for different operation,
and we can just use a variant to record the operation type.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This patch implement the RAID5/6 common data repair function, the
implementation is similar to the scrub on the other RAID such as
RAID1, the differentia is that we don't read the data from the
mirror, we use the data repair function of RAID5/6.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Because we will reuse bbio and raid_map during the scrub later, it is
better that we don't change any variant of bbio and don't free it at
the end of IO request. So we introduced similar variants into the raid
bio, and don't access those bbio's variants any more.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
bbio_ret in this condition is always !NULL because previous code
already have a check-and-skip:
4908 if (!bbio_ret)
4909 goto out;
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns. I suspect that this is a mistake and that
the code only works because int3 is paranoid.
Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chris bisected a NULL pointer deference in task_sched_runtime() to
commit 6e998916df 'sched/cputime: Fix clock_nanosleep()/clock_gettime()
inconsistency'.
Chris observed crashes in atop or other /proc walking programs when he
started fork bombs on his machine. He assumed that this is a new exit
race, but that does not make any sense when looking at that commit.
What's interesting is that, the commit provides update_curr callbacks
for all scheduling classes except stop_task and idle_task.
While nothing can ever hit that via the clock_nanosleep() and
clock_gettime() interfaces, which have been the target of the commit in
question, the author obviously forgot that there are other code paths
which invoke task_sched_runtime()
do_task_stat(()
thread_group_cputime_adjusted()
thread_group_cputime()
task_cputime()
task_sched_runtime()
if (task_current(rq, p) && task_on_rq_queued(p)) {
update_rq_clock(rq);
up->sched_class->update_curr(rq);
}
If the stats are read for a stomp machine task, aka 'migration/N' and
that task is current on its cpu, this will happily call the NULL pointer
of stop_task->update_curr. Ooops.
Chris observation that this happens faster when he runs the fork bomb
makes sense as the fork bomb will kick migration threads more often so
the probability to hit the issue will increase.
Add the missing update_curr callbacks to the scheduler classes stop_task
and idle_task. While idle tasks cannot be monitored via /proc we have
other means to hit the idle case.
Fixes: 6e998916df 'sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency'
Reported-by: Chris Mason <clm@fb.com>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge x86-64 iret fixes from Andy Lutomirski:
"This addresses the following issues:
- an unrecoverable double-fault triggerable with modify_ldt.
- invalid stack usage in espfix64 failed IRET recovery from IST
context.
- invalid stack usage in non-espfix64 failed IRET recovery from IST
context.
It also makes a good but IMO scary change: non-espfix64 failed IRET
will now report the correct error. Hopefully nothing depended on the
old incorrect behavior, but maybe Wine will get confused in some
obscure corner case"
* emailed patches from Andy Lutomirski <luto@amacapital.net>:
x86_64, traps: Rework bad_iret
x86_64, traps: Stop using IST for #SS
x86_64, traps: Fix the espfix64 #DF fixup and rewrite it in C
It's possible for iretq to userspace to fail. This can happen because
of a bad CS, SS, or RIP.
Historically, we've handled it by fixing up an exception from iretq to
land at bad_iret, which pretends that the failed iret frame was really
the hardware part of #GP(0) from userspace. To make this work, there's
an extra fixup to fudge the gs base into a usable state.
This is suboptimal because it loses the original exception. It's also
buggy because there's no guarantee that we were on the kernel stack to
begin with. For example, if the failing iret happened on return from an
NMI, then we'll end up executing general_protection on the NMI stack.
This is bad for several reasons, the most immediate of which is that
general_protection, as a non-paranoid idtentry, will try to deliver
signals and/or schedule from the wrong stack.
This patch throws out bad_iret entirely. As a replacement, it augments
the existing swapgs fudge into a full-blown iret fixup, mostly written
in C. It's should be clearer and more correct.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On a 32-bit kernel, this has no effect, since there are no IST stacks.
On a 64-bit kernel, #SS can only happen in user code, on a failed iret
to user space, a canonical violation on access via RSP or RBP, or a
genuine stack segment violation in 32-bit kernel code. The first two
cases don't need IST, and the latter two cases are unlikely fatal bugs,
and promoting them to double faults would be fine.
This fixes a bug in which the espfix64 code mishandles a stack segment
violation.
This saves 4k of memory per CPU and a tiny bit of code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's nothing special enough about the espfix64 double fault fixup to
justify writing it in assembly. Move it to C.
This also fixes a bug: if the double fault came from an IST stack, the
old asm code would return to a partially uninitialized stack frame.
Fixes: 3891a04aaf
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull ARM SoC fixes from Olof Johansson:
"A collection of fixes this week:
- A set of clock fixes for shmobile platforms
- A fix for tegra that moves serial port labels to be per board.
We're choosing to merge this for 3.18 because the labels will start
being parsed in 3.19, and without this change serial port numbers
that used to be stable since the dawn of time will change numbers.
- A few other DT tweaks for Tegra.
- A fix for multi_v7_defconfig that makes it stop spewing cpufreq
errors on Arndale (Exynos)"
* tag 'armsoc-for-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: multi_v7_defconfig: fix failure setting CPU voltage by enabling dependent I2C controller
ARM: tegra: roth: Fix SD card VDD_IO regulator
ARM: tegra: Remove eMMC vmmc property for roth/tn7
ARM: dts: tegra: move serial aliases to per-board
ARM: tegra: Add serial port labels to Tegra124 DT
ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
ARM: shmobile: r8a7740 dtsi: Correct IIC0 parent clock
ARM: shmobile: r8a7790: Fix SD3CKCR address to device tree
ARM: shmobile: r8a7740 legacy: Correct IIC0 parent clock
ARM: shmobile: r8a7740 legacy: Add missing INTCA clock for irqpin module
ARM: shmobile: r8a7790: Fix SD3CKCR address
ARM: dts: sun6i: Re-parent ahb1_mux to pll6 as required by dma controller
Pull percpu fix from Tejun Heo:
"This contains one patch to fix a race condition which can lead to
percpu_ref using a percpu pointer which is corrupted with a set DEAD
bit. The bug was introduced while separating out the ATOMIC mode flag
from the DEAD flag. The fix is pretty straight forward.
I just committed the patch to the percpu tree but am sending out the
pull request early as I'll be on vacation for a week. The patch
should be fairly safe and while the latency will be higher I'll be
checking emails"
* 'for-3.18-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu-ref: fix DEAD flag contamination of percpu pointer
Pull btrfs deadlock fix from Chris Mason:
"This has a fix for a long standing deadlock that we've been trying to
nail down for a while. It ended up being a bad interaction with the
fair reader/writer locks and the order btrfs reacquires locks in the
btree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix lockups from btrfs_clear_path_blocking
While decoupling ATOMIC and DEAD flags, f47ad45784 ("percpu_ref:
decouple switching to percpu mode and reinit") updated
__ref_is_percpu() so that it only tests ATOMIC flag to determine
whether the ref is in percpu mode or not; however, while DEAD implies
ATOMIC, the two flags are set separately during percpu_ref_kill() and
if __ref_is_percpu() races percpu_ref_kill(), it may see DEAD w/o
ATOMIC. Because __ref_is_percpu() returns @ref->percpu_count_ptr
value verbatim as the percpu pointer after testing ATOMIC, the pointer
may now be contaminated with the DEAD flag.
This can be fixed by clearing the flag bits before returning the
pointer which was the fix proposed by Shaohua; however, as DEAD
implies ATOMIC, we can just test for both flags at once and avoid the
explicit masking.
Update __ref_is_percpu() so that it tests that both ATOMIC and DEAD
are clear before returning @ref->percpu_count_ptr as the percpu
pointer.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-Reviewed-by: Shaohua Li <shli@kernel.org>
Link: http://lkml.kernel.org/r/995deb699f5b873c45d667df4add3b06f73c2c25.1416638887.git.shli@kernel.org
Fixes: f47ad45784 ("percpu_ref: decouple switching to percpu mode and reinit")
Pull timer fix from Thomas Gleixner:
"A single bugfix for an init order problem in the sun4i subarch
clockevents code"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clockevent: sun4i: Fix race condition in the probe code
Pull vfs fixes from Al Viro:
"Assorted fixes, most in overlayfs land"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ovl: ovl_dir_fsync() cleanup
ovl: update MAINTAINERS
ovl: pass dentry into ovl_dir_read_merged()
ovl: use lockless_dereference() for upperdentry
ovl: allow filenames with comma
ovl: fix race in private xattr checks
ovl: fix remove/copy-up race
ovl: rename filesystem type to "overlay"
isofs: avoid unused function warning
vfs: fix reference leak in d_prune_aliases()
Pull networking fixes from David Miller:
1) Fix BUG when decrypting empty packets in mac80211, from Ronald Wahl.
2) nf_nat_range is not fully initialized and this is copied back to
userspace, from Daniel Borkmann.
3) Fix read past end of b uffer in netfilter ipset, also from Dan
Carpenter.
4) Signed integer overflow in ipv4 address mask creation helper
inet_make_mask(), from Vincent BENAYOUN.
5) VXLAN, be2net, mlx4_en, and qlcnic need ->ndo_gso_check() methods to
properly describe the device's capabilities, from Joe Stringer.
6) Fix memory leaks and checksum miscalculations in openvswitch, from
Pravin B SHelar and Jesse Gross.
7) FIB rules passes back ambiguous error code for unreachable routes,
making behavior confusing for userspace. Fix from Panu Matilainen.
8) ieee802154fake_probe() doesn't release resources properly on error,
from Alexey Khoroshilov.
9) Fix skb_over_panic in add_grhead(), from Daniel Borkmann.
10) Fix access of stale slave pointers in bonding code, from Nikolay
Aleksandrov.
11) Fix stack info leak in PPP pptp code, from Mathias Krause.
12) Cure locking bug in IPX stack, from Jiri Bohac.
13) Revert SKB fclone memory freeing optimization that is racey and can
allow accesses to freed up memory, from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (71 commits)
tcp: Restore RFC5961-compliant behavior for SYN packets
net: Revert "net: avoid one atomic operation in skb_clone()"
virtio-net: validate features during probe
cxgb4 : Fix DCB priority groups being returned in wrong order
ipx: fix locking regression in ipx_sendmsg and ipx_recvmsg
openvswitch: Don't validate IPv6 label masks.
pptp: fix stack info leak in pptp_getname()
brcmfmac: don't include linux/unaligned/access_ok.h
cxgb4i : Don't block unload/cxgb4 unload when remote closes TCP connection
ipv6: delete protocol and unregister rtnetlink when cleanup
net/mlx4_en: Add VXLAN ndo calls to the PF net device ops too
bonding: fix curr_active_slave/carrier with loadbalance arp monitoring
mac80211: minstrel_ht: fix a crash in rate sorting
vxlan: Inline vxlan_gso_check().
can: m_can: update to support CAN FD features
can: m_can: fix incorrect error messages
can: m_can: add missing delay after setting CCCR_INIT bit
can: m_can: fix not set can_dlc for remote frame
can: m_can: fix possible sleep in napi poll
can: m_can: add missing message RAM initialization
...
Pull drm fixes from Dave Airlie:
"Just two radeon and two intel fixes: endian and regression fixes"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon: fix endian swapping in vbios fetch for tdp table
drm/radeon: disable native backlight control on pre-r6xx asics (v2)
drm/i915: Kick fbdev before vgacon
drm/i915: drop WaSetupGtModeTdRowDispatch:snb
