We have a few problems when returning to userspace. This is a
quick set of fixes for 3.3, I'll look into a more comprehensive
rework for 3.4. This fixes:
- We kept interrupts soft-disabled when schedule'ing or calling
do_signal when returning to userspace as a result of a hardware
interrupt.
- Rename do_signal to do_notify_resume like all other archs (and
do_signal_pending back to do_signal, which it was before Roland
changed it).
- Add the missing call to key_replace_session_keyring() to
do_notify_resume().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
We moved all our pSeries idle loops to the cpu idle framework
so we really want it to come up by default.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In commit 54321242af ("Disable interrupts early in Program Check"), we
switched from enabling to disabling interrupts in program_check_common.
Whereas ENABLE_INTS leaves r3 untouched, if lockdep is enabled DISABLE_INTS
calls into lockdep code and will clobber r3. That means we pass a bogus
struct pt_regs* into program_check_exception() and all hell breaks loose.
So load our regs pointer into r3 after we call DISABLE_INTS.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This has been obsolescent for a while; time for the final push.
In adjacent context, replaced old cpus_* with cpumask_*.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
(And define it properly for x86-32, which had its 'current_task'
declaration in separate from x86-64)
Bitten by my dislike for modules on the machines I use, and the fact
that apparently nobody else actually wanted to test the patches I sent
out.
Snif. Nobody else cares.
Anyway, we probably should uninline the 'kernel_fpu_begin()' function
that is what modules actually use and that references this, but this is
the minimal fix for now.
Reported-by: Josh Boyer <jwboyer@gmail.com>
Reported-and-tested-by: Jongman Heo <jongman.heo@samsung.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Assorted fixes, sat in -next for a week or so...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ocfs2: deal with wraparounds of i_nlink in ocfs2_rename()
vfs: fix compat_sys_stat() handling of overflows in st_nlink
quota: Fix deadlock with suspend and quotas
vfs: Provide function to get superblock and wait for it to thaw
vfs: fix panic in __d_lookup() with high dentry hashtable counts
autofs4 - fix lockdep splat in autofs
vfs: fix d_inode_lookup() dentry ref leak
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
[S390] correct ktime to tod clock comparator conversion
[S390] 3215 deadlock with tty_wakeup
[S390] incorrect PageTables counter for kvm page tables
[S390] idle: avoid RCU usage in extended quiescent state
This makes us recognize when we try to restore FPU state that matches
what we already have in the FPU on this CPU, and avoids the restore
entirely if so.
To do this, we add two new data fields:
- a percpu 'fpu_owner_task' variable that gets written any time we
update the "has_fpu" field, and thus acts as a kind of back-pointer
to the task that owns the CPU. The exception is when we save the FPU
state as part of a context switch - if the save can keep the FPU
state around, we leave the 'fpu_owner_task' variable pointing at the
task whose FP state still remains on the CPU.
- a per-thread 'last_cpu' field, that indicates which CPU that thread
used its FPU on last. We update this on every context switch
(writing an invalid CPU number if the last context switch didn't
leave the FPU in a lazily usable state), so we know that *that*
thread has done nothing else with the FPU since.
These two fields together can be used when next switching back to the
task to see if the CPU still matches: if 'fpu_owner_task' matches the
task we are switching to, we know that no other task (or kernel FPU
usage) touched the FPU on this CPU in the meantime, and if the current
CPU number matches the 'last_cpu' field, we know that this thread did no
other FP work on any other CPU, so the FPU state on the CPU must match
what was saved on last context switch.
In that case, we can avoid the 'f[x]rstor' entirely, and just clear the
CR0.TS bit.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This inlines what is usually just a couple of instructions, but more
importantly it also fixes the theoretical error case (can that FPU
restore really ever fail? Maybe we should remove the checking).
We can't start sending signals from within the scheduler, we're much too
deep in the kernel and are holding the runqueue lock etc. So don't
bother even trying.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes sure we clear the FPU usage counter for newly created tasks,
just so that we start off in a known state (for example, don't try to
preload the FPU state on the first task switch etc).
It also fixes a thinko in when we increment the fpu_counter at task
switch time, introduced by commit 34ddc81a23 ("i387: re-introduce FPU
state preloading at context switch time"). We should increment the
*new* task fpu_counter, not the old task, and only if we decide to use
that state (whether lazily or preloaded).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
time_t was used in the signature and key packet headers,
which is typedef of long and is different on 32 and 64 bit architectures.
Signature and key format should be independent of architecture.
Similar to GPG, I have changed the type to uint32_t.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: James Morris <jmorris@namei.org>
These are the bug fixes that have accumulated since 3.3-rc3 in arm-soc.
The majority of them are regression fixes for stuff that broke during
the merge 3.3 window.
The notable ones are:
* The at91 ata drivers both broke because of an earlier cleanup patch that
some other patches were based on. Jean-Christophe decided to remove
the legacy at91_ide driver and fix the new-style at91-pata driver while
keeping the cleanup patch. I almost rejected the patches for being too
late and too big but in the end decided to accept them because they
fix a regression.
* A patch fixing build breakage from the sysdev-to-device conversion
colliding with other changes touches a number of mach-s3c files.
* b0654037 "ARM: orion: Fix Orion5x GPIO regression from MPP cleanup"
is a mechanical change that unfortunately touches a lot of lines
that should up in the diffstat.
* tag 'fixes-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (28 commits)
ARM: at91: drop ide driver in favor of the pata one
pata/at91: use newly introduced SMC accessors
ARM: at91: add accessor to manage SMC
ARM: at91:rtc/rtc-at91sam9: ioremap register bank
ARM: at91: USB AT91 gadget registration for module
ep93xx: fix build of vision_ep93xx.c
ARM: OMAP2xxx: PM: fix OMAP2xxx-specific UART idle bug in v3.3
ARM: orion: Fix USB phy for orion5x.
ARM: orion: Fix Orion5x GPIO regression from MPP cleanup
ARM: EXYNOS: Add cpu-offset property in gic device tree node
ARM: EXYNOS: Bring exynos4-dt up to date
ARM: OMAP3: cm-t35: fix section mismatch warning
ARM: OMAP2: Fix the OMAP2 only build break seen with 2011+ ARM tool-chains
ARM: tegra: paz00: fix wrong UART port on mini-pcie plug
ARM: tegra: paz00: fix wrong SD1 power gpio
i2c: tegra: Add devexit_p() for remove
ARM: EXYNOS: Correct M-5MOLS sensor clock frequency on Universal C210 board
ARM: EXYNOS: Correct framebuffer window size on Nuri board
ARM: SAMSUNG: Fix missing api-change from subsys_interface change
ARM: EXYNOS: Fix "warning: initialization from incompatible pointer type"
...
1) VETH_INFO_PEER netlink attribute needs to have it's size validated,
from Thomas Graf.
2) 'poll' module option of bnx2x driver crashes the machine, just remove
it. From Michal Schmidt.
3) ks8851_mll driver reads the irq number from two places, but only
initializes one of them, oops. Use only one location and fix this
problem, from Jan Weitzel.
4) Fix buffer overrun and unicast sterring bugs in mellanox mlx4 driver,
from Eugenia Emantayev.
5) Swapped kcalloc() args in RxRPC and mlx4, from Axel Lin.
6) PHY MDIO device name regression fixes from Florian Fainelli.
7) If the wake event IRQ line is different from the netdevice one, we
have to properly route it to the stmmac interrupt handler. From
Francesco Virlinzi.
8) Fix rwlock lock initialization ordering bug in mac80211, from
Mohammed Shafi Shajakhan.
9) TCP lost_cnt can get out of sync, and in fact go negative, in certain
circumstances. Fix the way we specify what sequence range to operate
on in tcp_sacktag_one() to fix this bug. From Neal Cardwell.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
net/ethernet: ks8851_mll fix irq handling
veth: Enforce minimum size of VETH_INFO_PEER
stmmac: update the driver version to Feb 2012 (v2)
stmmac: move hw init in the probe (v2)
stmmac: request_irq when use an ext wake irq line (v2)
stmmac: do not discard frame on dribbling bit assert
ipheth: Add iPhone 4S
mlx4: add unicast steering entries to resource_tracker
mlx4: fix QP tree trashing
mlx4: fix buffer overrun
3c59x: shorten timer period for slave devices
netpoll: netpoll_poll_dev() should access dev->flags
RxRPC: Fix kcalloc parameters swapped
bnx2x: remove the 'poll' module option
tcp: fix tcp_shifted_skb() adjustment of lost_cnt_hint for FACK
ks8851: Fix NOHZ local_softirq_pending 08 warning
bnx2x: fix bnx2x_storm_stats_update() on big endian
ixp4xx-eth: fix PHY name to match MDIO bus name
octeon: fix PHY name to match MDIO bus name
fec: fix PHY name to match fixed MDIO bus name
...
Fixes a bootstrapping issue for some registers when a less commonly used
method for register cache initialisation is used. Only affects a fairly
small proportion of users that both don't use explicit register defaults
and do use the cache.
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: Fix cache defaults initialization from raw cache defaults
Fixes maximum filename length and filesystem type reporting in statfs() calls
and also fixes stale inode mode bits on eCryptfs inodes after a POSIX ACL was
set on the lower filesystem's inode.
* tag 'ecryptfs-3.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
ecryptfs: remove the second argument of k[un]map_atomic()
eCryptfs: Copy up lower inode attrs after setting lower xattr
eCryptfs: Improve statfs reporting
pinctrl fixes for v3.3
* tag 'pinctrl-for-torvalds-20120216' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: restore pin naming
Here are a few more fixes for powerpc. Some are regressions, the rest
is simple/obvious/nasty enough that I deemed it good to go now.
Here's also step one of deprecating legacy iSeries support: we are
removing it from the main defconfig.
Nobody seems to be using it anymore and the code is nasty to maintain,
(involves horrible hacks in various low level areas of the kernel) so we
plan to actually rip it out at some point. For now let's just avoid
building it by default. Stephen will proceed to do the actual removal
later (probably 3.4 or 3.5).
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events
powerpc/adb: Use set_current_state()
powerpc: Disable interrupts early in Program Check
powerpc: Remove legacy iSeries from ppc64_defconfig
powerpc/fsl/pci: Fix PCIe fixup regression
powerpc: Fix kernel log of oops/panic instruction dump
One regression fix for SR-IOV on PPC and a couple of misc fixes from
Yinghai.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci:
PCI: Fix pci cardbus removal
PCI: set pci sriov page size before reading SRIOV BAR
PCI: workaround hard-wired bus number V2
3 radeon fixes, I have some exynos fixes to push later but I'll queue
them separately once I've looked them over a bit.
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon/kms: fix MSI re-arm on rv370+
drm/radeon/kms/atom: bios scratch reg handling updates
drm/radeon/kms: drop lock in return path of radeon_fence_count_emitted.
After all the FPU state cleanups and finally finding the problem that
caused all our FPU save/restore problems, this re-introduces the
preloading of FPU state that was removed in commit b3b0870ef3 ("i387:
do not preload FPU state at task switch time").
However, instead of simply reverting the removal, this reimplements
preloading with several fixes, most notably
- properly abstracted as a true FPU state switch, rather than as
open-coded save and restore with various hacks.
In particular, implementing it as a proper FPU state switch allows us
to optimize the CR0.TS flag accesses: there is no reason to set the
TS bit only to then almost immediately clear it again. CR0 accesses
are quite slow and expensive, don't flip the bit back and forth for
no good reason.
- Make sure that the same model works for both x86-32 and x86-64, so
that there are no gratuitous differences between the two due to the
way they save and restore segment state differently due to
architectural differences that really don't matter to the FPU state.
- Avoid exposing the "preload" state to the context switch routines,
and in particular allow the concept of lazy state restore: if nothing
else has used the FPU in the meantime, and the process is still on
the same CPU, we can avoid restoring state from memory entirely, just
re-expose the state that is still in the FPU unit.
That optimized lazy restore isn't actually implemented here, but the
infrastructure is set up for it. Of course, older CPU's that use
'fnsave' to save the state cannot take advantage of this, since the
state saving also trashes the state.
In other words, there is now an actual _design_ to the FPU state saving,
rather than just random historical baggage. Hopefully it's easier to
follow as a result.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves the bit that indicates whether a thread has ownership of the
FPU from the TS_USEDFPU bit in thread_info->status to a word of its own
(called 'has_fpu') in task_struct->thread.has_fpu.
This fixes two independent bugs at the same time:
- changing 'thread_info->status' from the scheduler causes nasty
problems for the other users of that variable, since it is defined to
be thread-synchronous (that's what the "TS_" part of the naming was
supposed to indicate).
So perfectly valid code could (and did) do
ti->status |= TS_RESTORE_SIGMASK;
and the compiler was free to do that as separate load, or and store
instructions. Which can cause problems with preemption, since a task
switch could happen in between, and change the TS_USEDFPU bit. The
change to TS_USEDFPU would be overwritten by the final store.
In practice, this seldom happened, though, because the 'status' field
was seldom used more than once, so gcc would generally tend to
generate code that used a read-modify-write instruction and thus
happened to avoid this problem - RMW instructions are naturally low
fat and preemption-safe.
- On x86-32, the current_thread_info() pointer would, during interrupts
and softirqs, point to a *copy* of the real thread_info, because
x86-32 uses %esp to calculate the thread_info address, and thus the
separate irq (and softirq) stacks would cause these kinds of odd
thread_info copy aliases.
This is normally not a problem, since interrupts aren't supposed to
look at thread information anyway (what thread is running at
interrupt time really isn't very well-defined), but it confused the
heck out of irq_fpu_usable() and the code that tried to squirrel
away the FPU state.
(It also caused untold confusion for us poor kernel developers).
It also turns out that using 'task_struct' is actually much more natural
for most of the call sites that care about the FPU state, since they
tend to work with the task struct for other reasons anyway (ie
scheduling). And the FPU data that we are going to save/restore is
found there too.
Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to
the %esp issue.
Cc: Arjan van de Ven <arjan@linux.intel.com>
Reported-and-tested-by: Raphael Prevost <raphael@buro.asia>
Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The conversion of the ktime to a value suitable for the clock comparator
does not take changes to wall_to_monotonic into account. In fact the
conversion just needs the boot clock (sched_clock_base_cc) and the
total_sleep_time.
This is applicable to 3.2+ kernels.
CC: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Benjamin Herrenschmidt
Michael Ellerman
Rusty Russell
Linus Torvalds
Dmitry Kasatkin
Martin Schwidefsky