- 27 2月, 2012 6 次提交
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由 Benoit Cousson 提交于
Update the DTS with the proper information required by the INTC bindings. - Add the number of interrupt lines - Add the reg and the compatible entries. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NRob Herring <rob.herring@calxeda.com> Acked-by: NGrant Likely <grant.likely@secretlab.ca>
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由 Benoit Cousson 提交于
Add a function to initialize the OMAP2/3 interrupt controller (INTC) using a device tree node. This version take advantage of the new irq_domain_add_legacy API. Replace some printk() with the proper pr_ macro. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Cc: Tony Lindgren <tony@atomide.com> Acked-by: NRob Herring <rob.herring@calxeda.com> Acked-by: NGrant Likely <grant.likely@secretlab.ca>
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由 Grant Likely 提交于
TWL4030 depends on IRQ_DOMAIN support, so this patch selects it in Kconfig. It used to be that CONFIG_IRQ_DOMAIN must only be selected by the architecture, but recent cleanups have fixed it so that it is safe to select from anywhere. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> [grant.likely: Changed from a depends to a select] Signed-off-by: NGrant Likely <grant.likely@secretlab.ca> Cc: Samuel Ortiz <sameo@linux.intel.com>
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由 Grant Likely 提交于
Sparc has its own helpers for translating address ranges when the device tree is parsed at boot time, and it isn't able to use of_platform_populate(). However, there are some device drivers that want to use that function on other DT enabled platforms (ie. TWL4030). This patch adds an empty of_platform_populate() implementation that returns an error when CONFIG_OF_ADDRESS is not selected. Signed-off-by: NGrant Likely <grant.likely@secretlab.ca> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Samuel Ortiz <sameo@linux.intel.com>
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由 Grant Likely 提交于
Several architectures define their own empty irq_dispose_mapping(). Since the irq_domain code is centralized now, there is little need to do so. This patch removes them and creates a new empty copy when !CONFIG_IRQ_DOMAIN is selected. The patch also means that IRQ_DOMAIN becomes selectable on all architectures. Signed-off-by: NGrant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jonas Bonn <jonas@southpole.se> Cc: sparclinux@vger.kernel.org Cc: linux@lists.openrisc.net
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- 25 2月, 2012 6 次提交
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由 Tony Lindgren 提交于
Merge branch 'for_3.4/dts_updates' of git://git.kernel.org/pub/scm/linux/kernel/git/bcousson/linux-omap-dt into dt
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由 Vaibhav Hiremath 提交于
Add OMAP3 EVM (OMAP3530, AM/DM37x) DTS file to use the omap3.dtsi SoC file, along with memory node information. Signed-off-by: NVaibhav Hiremath <hvaibhav@ti.com> Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NGrant Likely <grant.likely@secretlab.ca>
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由 Benoit Cousson 提交于
The GIC binding was updated in 3.2 and expects 3 interrupt-cells. - Update the #interrupt-cells Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NRob Herring <rob.herring@calxeda.com>
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由 Benoit Cousson 提交于
Add i2c controllers nodes into the main ocp bus. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NGrant Likely <grant.likely@secretlab.ca> Acked-by: NRob Herring <rob.herring@calxeda.com>
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由 Benoit Cousson 提交于
Add i2c controllers nodes into the main ocp bus. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NRob Herring <rob.herring@calxeda.com> Acked-by: NGrant Likely <grant.likely@secretlab.ca>
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由 Grant Likely 提交于
This patch makes IRQ_DOMAIN usable on MIPS. It uses an ugly workaround to preserve current behaviour so that MIPS has time to add irq_domain registration to the irq controller drivers. The workaround will be removed in Linux v3.6 Signed-off-by: NGrant Likely <grant.likely@secretlab.ca> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org
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- 24 2月, 2012 2 次提交
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由 Tony Lindgren 提交于
Otherwise we get: warning: (ARCH_OMAP2PLUS) selects PROC_DEVICETREE which has unmet direct dependencies (OF && PROC_FS && !SPARC) Signed-off-by: NTony Lindgren <tony@atomide.com>
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由 Grant Likely 提交于
This patch removes the x86-specific definition of irq_domain and replaces it with the common implementation. Signed-off-by: NGrant Likely <grant.likely@secretlab.ca> Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Thomas Gleixner <tglx@linutronix.de>
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- 23 2月, 2012 1 次提交
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由 Paul Gortmaker 提交于
The commit bae1d8f1 (linux-next) "irq_domain/powerpc: Use common irq_domain structure instead of irq_host" made this change: -static struct irq_host *flipper_irq_host; +static struct irq_domain *flipper_irq_host; and this change: -static struct irq_host *hlwd_irq_host; +static struct irq_domain *hlwd_irq_host; The intent was to change the type, and not the name, but then in a couple of instances, it looks like the sed to change the irq_domain_ops name inadvertently also changed the irq_host name where it was not supposed to, causing build failures. Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
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- 19 2月, 2012 12 次提交
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由 Linus Torvalds 提交于
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc由 Linus Torvalds 提交于
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" ...
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/net由 Linus Torvalds 提交于
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 ...
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git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap由 Linus Torvalds 提交于
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
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由 Linus Torvalds 提交于
Merge tag 'ecryptfs-3.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs 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
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl由 Linus Torvalds 提交于
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
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git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc由 Linus Torvalds 提交于
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
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git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci由 Linus Torvalds 提交于
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
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git://people.freedesktop.org/~airlied/linux由 Linus Torvalds 提交于
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.
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6由 Linus Torvalds 提交于
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: sha512 - use standard ror64()
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由 Linus Torvalds 提交于
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 b3b0870e ("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: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Linus Torvalds 提交于
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: NRaphael Prevost <raphael@buro.asia> Acked-and-tested-by: NSuresh Siddha <suresh.b.siddha@intel.com> Tested-by: NPeter Anvin <hpa@zytor.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 18 2月, 2012 1 次提交
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由 Tony Lindgren 提交于
Merge branch 'for_3.4/dt_base' of git://git.kernel.org/pub/scm/linux/kernel/git/bcousson/linux-omap-dt into dt
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- 17 2月, 2012 12 次提交
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由 Linus Torvalds 提交于
The AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is pending. In order to not leak FIP state from one process to another, we need to do a floating point load after the fxsave of the old process, and before the fxrstor of the new FPU state. That resets the state to the (uninteresting) kernel load, rather than some potentially sensitive user information. We used to do this directly after the FPU state save, but that is actually very inconvenient, since it (a) corrupts what is potentially perfectly good FPU state that we might want to lazy avoid restoring later and (b) on x86-64 it resulted in a very annoying ordering constraint, where "__unlazy_fpu()" in the task switch needs to be delayed until after the DS segment has been reloaded just to get the new DS value. Coupling it to the fxrstor instead of the fxsave automatically avoids both of these issues, and also ensures that we only do it when actually necessary (the FP state after a save may never actually get used). It's simply a much more natural place for the leaked state cleanup. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Linus Torvalds 提交于
Yes, taking the trap to re-load the FPU/MMX state is expensive, but so is spending several days looking for a bug in the state save/restore code. And the preload code has some rather subtle interactions with both paravirtualization support and segment state restore, so it's not nearly as simple as it should be. Also, now that we no longer necessarily depend on a single bit (ie TS_USEDFPU) for keeping track of the state of the FPU, we migth be able to do better. If we are really switching between two processes that keep touching the FP state, save/restore is inevitable, but in the case of having one process that does most of the FPU usage, we may actually be able to do much better than the preloading. In particular, we may be able to keep track of which CPU the process ran on last, and also per CPU keep track of which process' FP state that CPU has. For modern CPU's that don't destroy the FPU contents on save time, that would allow us to do a lazy restore by just re-enabling the existing FPU state - with no restore cost at all! Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Benoit Cousson 提交于
Follow the DTS convention and thus name the nodes <name>@<address> without any '0x' prefix in the physical address. Suggested-by: NTony Lindgren <tony@atomide.com> Signed-off-by: NBenoit Cousson <b-cousson@ti.com>
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由 Benoit Cousson 提交于
The devices that can act as an interrupt controller like the GPIO are going to be handled using the IRQ domain mechanism in order to avoid the static IRQ mapping done so far inside plat-omap/irqs.h. Enable IRQ_DOMAIN by default to allow the drivers shared with OMAP2+ to compile properly on OMAP1 platforms. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Cc: Tony Lindgren <tony@atomide.com>
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由 Benoit Cousson 提交于
In the case of DT, the PMIC and SR initialization will be done using a completely different mechanism. Disable this part if a DT blob is available. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NKevin Hilman <khilman@ti.com> Acked-by: NRob Herring <rob.herring@calxeda.com> Acked-by: NGrant Likely <grant.likely@secretlab.ca>
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由 Benoit Cousson 提交于
This warning becomes a little bit too verbose with the increase of device nodes in some DTS files. Change it to debug only. Signed-off-by: NBenoit Cousson <b-cousson@ti.com> Acked-by: NKevin Hilman <khilman@ti.com>
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由 Cong Wang 提交于
Signed-off-by: NCong Wang <amwang@redhat.com> Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
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由 Tyler Hicks 提交于
After passing through a ->setxattr() call, eCryptfs needs to copy the inode attributes from the lower inode to the eCryptfs inode, as they may have changed in the lower filesystem's ->setxattr() path. One example is if an extended attribute containing a POSIX Access Control List is being set. The new ACL may cause the lower filesystem to modify the mode of the lower inode and the eCryptfs inode would need to be updated to reflect the new mode. https://launchpad.net/bugs/926292Signed-off-by: NTyler Hicks <tyhicks@canonical.com> Reported-by: NSebastien Bacher <seb128@ubuntu.com> Cc: John Johansen <john.johansen@canonical.com> Cc: <stable@vger.kernel.org>
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由 Tyler Hicks 提交于
statfs() calls on eCryptfs files returned the wrong filesystem type and, when using filename encryption, the wrong maximum filename length. If mount-wide filename encryption is enabled, the cipher block size and the lower filesystem's max filename length will determine the max eCryptfs filename length. Pre-tested, known good lengths are used when the lower filesystem's namelen is 255 and a cipher with 8 or 16 byte block sizes is used. In other, less common cases, we fall back to a safe rounded-down estimate when determining the eCryptfs namelen. https://launchpad.net/bugs/885744Signed-off-by: NTyler Hicks <tyhicks@canonical.com> Reported-by: NKees Cook <keescook@chromium.org> Reviewed-by: NKees Cook <keescook@chromium.org> Reviewed-by: NJohn Johansen <john.johansen@canonical.com>
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由 Linus Torvalds 提交于
This creates three helper functions that do the TS_USEDFPU accesses, and makes everybody that used to do it by hand use those helpers instead. In addition, there's a couple of helper functions for the "change both CR0.TS and TS_USEDFPU at the same time" case, and the places that do that together have been changed to use those. That means that we have fewer random places that open-code this situation. The intent is partly to clarify the code without actually changing any semantics yet (since we clearly still have some hard to reproduce bug in this area), but also to make it much easier to use another approach entirely to caching the CR0.TS bit for software accesses. Right now we use a bit in the thread-info 'status' variable (this patch does not change that), but we might want to make it a full field of its own or even make it a per-cpu variable. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Linus Torvalds 提交于
Touching TS_USEDFPU without touching CR0.TS is confusing, so don't do it. By moving it into the callers, we always do the TS_USEDFPU next to the CR0.TS accesses in the source code, and it's much easier to see how the two go hand in hand. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Linus Torvalds 提交于
Commit 5b1cbac3 ("i387: make irq_fpu_usable() tests more robust") added a sanity check to the #NM handler to verify that we never cause the "Device Not Available" exception in kernel mode. However, that check actually pinpointed a (fundamental) race where we do cause that exception as part of the signal stack FPU state save/restore code. Because we use the floating point instructions themselves to save and restore state directly from user mode, we cannot do that atomically with testing the TS_USEDFPU bit: the user mode access itself may cause a page fault, which causes a task switch, which saves and restores the FP/MMX state from the kernel buffers. This kind of "recursive" FP state save is fine per se, but it means that when the signal stack save/restore gets restarted, it will now take the '#NM' exception we originally tried to avoid. With preemption this can happen even without the page fault - but because of the user access, we cannot just disable preemption around the save/restore instruction. There are various ways to solve this, including using the "enable/disable_page_fault()" helpers to not allow page faults at all during the sequence, and fall back to copying things by hand without the use of the native FP state save/restore instructions. However, the simplest thing to do is to just allow the #NM from kernel space, but fix the race in setting and clearing CR0.TS that this all exposed: the TS bit changes and the TS_USEDFPU bit absolutely have to be atomic wrt scheduling, so while the actual state save/restore can be interrupted and restarted, the act of actually clearing/setting CR0.TS and the TS_USEDFPU bit together must not. Instead of just adding random "preempt_disable/enable()" calls to what is already excessively ugly code, this introduces some helper functions that mostly mirror the "kernel_fpu_begin/end()" functionality, just for the user state instead. Those helper functions should probably eventually replace the other ad-hoc CR0.TS and TS_USEDFPU tests too, but I'll need to think about it some more: the task switching functionality in particular needs to expose the difference between the 'prev' and 'next' threads, while the new helper functions intentionally were written to only work with 'current'. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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