- 30 Jun, 2020 40 commits
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Lukas Wunner authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 9dd277ff ] The BCM2835 SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835_spi_remove() tears down the DMA channels and turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_controller(). Note that the struct spi_controller as well as the driver-private data are not freed until after bcm2835_spi_remove() has finished, so accessing them is safe. Fixes: 247263db ("spi: bcm2835: use devm_spi_register_master()") Signed-off-by:
Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v3.13+ Link: https://lore.kernel.org/r/2397dd70cdbe95e0bc4da2b9fca0f31cb94e5aed.1589557526.git.lukas@wunner.deSigned-off-by:
Mark Brown <broonie@kernel.org> Signed-off-by:
Sasha Levin <sashal@kernel.org> Signed-off-by:
Kamal Mostafa <kamal@canonical.com> Signed-off-by:
Khalid Elmously <khalid.elmously@canonical.com>
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Lukas Wunner authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 32e5b572 ] The PXA2xx SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes pxa2xx_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: pxa2xx_spi_remove() disables the chip, rendering the SPI bus inaccessible even though the SPI controller is still registered. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. Because their drivers cannot access the SPI bus, e.g. to quiesce interrupts, the slave devices may be left in an improper state. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unregistering the controller and specifically after unbinding of slaves. Fix by reverting to the non-devm variant of spi_register_controller(). An alternative approach would be to use device-managed functions for all steps in pxa2xx_spi_remove(), e.g. by calling devm_add_action_or_reset() on probe. However that approach would add more LoC to the driver and it wouldn't lend itself as well to backporting to stable. The improper use of devm_spi_register_controller() was introduced in 2013 by commit a807fcd0 ("spi: pxa2xx: use devm_spi_register_master()"), but all earlier versions of the driver going back to 2006 were likewise broken because they invoked spi_unregister_master() at the end of pxa2xx_spi_remove(), rather than at the beginning. Fixes: e0c9905e ("[PATCH] SPI: add PXA2xx SSP SPI Driver") Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: stable@vger.kernel.org # v2.6.17+ Cc: Tsuchiya Yuto <kitakar@gmail.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206403#c1 Link: https://lore.kernel.org/r/834c446b1cf3284d2660f1bee1ebe3e737cd02a9.1590408496.git.lukas@wunner.deSigned-off-by:
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Lukas Wunner authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 84855678 ] When an SPI controller unregisters, it unbinds all its slave devices. For this, their drivers may need to access the SPI bus, e.g. to quiesce interrupts. However since commit ffbbdd21 ("spi: create a message queueing infrastructure"), spi_destroy_queue() is executed before unbinding the slaves. It sets ctlr->running = false, thereby preventing SPI bus access and causing unbinding of slave devices to fail. Fix by unbinding slaves before calling spi_destroy_queue(). Fixes: ffbbdd21 ("spi: create a message queueing infrastructure") Signed-off-by:
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Andy Shevchenko authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit ebc37af5 ] The device_for_each_child() doesn't require the returned value to be checked. Thus, drop the dummy variable completely and have no warning anymore: drivers/spi/spi.c: In function ‘spi_unregister_controller’: drivers/spi/spi.c:2480:6: warning: variable ‘dummy’ set but not used [-Wunused-but-set-variable] int dummy; ^~~~~ Signed-off-by:
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Lukas Wunner authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit ca8b19d6 ] The Designware SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes dw_spi_remove_host() before unregistering the SPI controller via devres_release_all(). This order is incorrect: dw_spi_remove_host() shuts down the chip, rendering the SPI bus inaccessible even though the SPI controller is still registered. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. Because their drivers cannot access the SPI bus, e.g. to quiesce interrupts, the slave devices may be left in an improper state. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unregistering the controller and specifically after unbinding of slaves. Fix by reverting to the non-devm variant of spi_register_controller(). An alternative approach would be to use device-managed functions for all steps in dw_spi_remove_host(), e.g. by calling devm_add_action_or_reset() on probe. However that approach would add more LoC to the driver and it wouldn't lend itself as well to backporting to stable. Fixes: 04f421e7 ("spi: dw: use managed resources") Signed-off-by:
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Sasha Levin authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 66b19d76 ] It is possible to get an interrupt as soon as it is requested. dw_spi_irq does spi_controller_get_devdata(master) and expects it to be different than NULL. However, spi_controller_set_devdata() is called after request_irq(), resulting in the following crash: CPU 0 Unable to handle kernel paging request at virtual address 00000030, epc == 8058e09c, ra == 8018ff90 [...] Call Trace: [<8058e09c>] dw_spi_irq+0x8/0x64 [<8018ff90>] __handle_irq_event_percpu+0x70/0x1d4 [<80190128>] handle_irq_event_percpu+0x34/0x8c [<801901c4>] handle_irq_event+0x44/0x80 [<801951a8>] handle_level_irq+0xdc/0x194 [<8018f580>] generic_handle_irq+0x38/0x50 [<804c6924>] ocelot_irq_handler+0x104/0x1c0 Signed-off-by:
Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by:
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Anthony Steinhauser authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 4d8df8cb ] Currently, it is possible to enable indirect branch speculation even after it was force-disabled using the PR_SPEC_FORCE_DISABLE option. Moreover, the PR_GET_SPECULATION_CTRL command gives afterwards an incorrect result (force-disabled when it is in fact enabled). This also is inconsistent vs. STIBP and the documention which cleary states that PR_SPEC_FORCE_DISABLE cannot be undone. Fix this by actually enforcing force-disabled indirect branch speculation. PR_SPEC_ENABLE called after PR_SPEC_FORCE_DISABLE now fails with -EPERM as described in the documentation. Fixes: 9137bb27 ("x86/speculation: Add prctl() control for indirect branch speculation") Signed-off-by:
Anthony Steinhauser <asteinhauser@google.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by:
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Anthony Steinhauser authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 21998a35 ] When STIBP is unavailable or enhanced IBRS is available, Linux force-disables the IBPB mitigation of Spectre-BTB even when simultaneous multithreading is disabled. While attempts to enable IBPB using prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, ...) fail with EPERM, the seccomp syscall (or its prctl(PR_SET_SECCOMP, ...) equivalent) which are used e.g. by Chromium or OpenSSH succeed with no errors but the application remains silently vulnerable to cross-process Spectre v2 attacks (classical BTB poisoning). At the same time the SYSFS reporting (/sys/devices/system/cpu/vulnerabilities/spectre_v2) displays that IBPB is conditionally enabled when in fact it is unconditionally disabled. STIBP is useful only when SMT is enabled. When SMT is disabled and STIBP is unavailable, it makes no sense to force-disable also IBPB, because IBPB protects against cross-process Spectre-BTB attacks regardless of the SMT state. At the same time since missing STIBP was only observed on AMD CPUs, AMD does not recommend using STIBP, but recommends using IBPB, so disabling IBPB because of missing STIBP goes directly against AMD's advice: https://developer.amd.com/wp-content/resources/Architecture_Guidelines_Update_Indirect_Branch_Control.pdf Similarly, enhanced IBRS is designed to protect cross-core BTB poisoning and BTB-poisoning attacks from user space against kernel (and BTB-poisoning attacks from guest against hypervisor), it is not designed to prevent cross-process (or cross-VM) BTB poisoning between processes (or VMs) running on the same core. Therefore, even with enhanced IBRS it is necessary to flush the BTB during context-switches, so there is no reason to force disable IBPB when enhanced IBRS is available. Enable the prctl control of IBPB even when STIBP is unavailable or enhanced IBRS is available. Fixes: 7cc765a6 ("x86/speculation: Enable prctl mode for spectre_v2_user") Signed-off-by:
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Thomas Lendacky authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 20c3a2c3 ] Different AMD processors may have different implementations of STIBP. When STIBP is conditionally enabled, some implementations would benefit from having STIBP always on instead of toggling the STIBP bit through MSR writes. This preference is advertised through a CPUID feature bit. When conditional STIBP support is requested at boot and the CPU advertises STIBP always-on mode as preferred, switch to STIBP "on" support. To show that this transition has occurred, create a new spectre_v2_user_mitigation value and a new spectre_v2_user_strings message. The new mitigation value is used in spectre_v2_user_select_mitigation() to print the new mitigation message as well as to return a new string from stibp_state(). Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by:
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Waiman Long authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit aa77bfb3 ] STIBP stands for Single Thread Indirect Branch Predictors. The acronym, however, can be easily mis-spelled as STIPB. It is perhaps due to the presence of another related term - IBPB (Indirect Branch Predictor Barrier). Fix the mis-spelling in the code. Signed-off-by:
Waiman Long <longman@redhat.com> Signed-off-by:
Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: KarimAllah Ahmed <karahmed@amazon.de> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/1544039368-9009-1-git-send-email-longman@redhat.comSigned-off-by:
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Michał Mirosław authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 951e2736 upstream. Prevent SNDRV_PCM_IOCTL_LINK linking stream to itself - the code can't handle it. Fixed commit is not where bug was introduced, but changes the context significantly. Cc: stable@vger.kernel.org Fixes: 0888c321 ("pcm_native: switch to fdget()/fdput()") Signed-off-by:
Michał Mirosław <mirq-linux@rere.qmqm.pl> Link: https://lore.kernel.org/r/89c4a2487609a0ed6af3ecf01cc972bdc59a7a2d.1591634956.git.mirq-linux@rere.qmqm.plSigned-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Lukas Wunner authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit b9dd3f6d upstream. The BCM2835aux SPI driver uses devm_spi_register_master() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835aux_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835aux_spi_remove() turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_master() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_master(). Note that the struct spi_master as well as the driver-private data are not freed until after bcm2835aux_spi_remove() has finished, so accessing them is safe. Fixes: 1ea29b39 ("spi: bcm2835aux: add bcm2835 auxiliary spi device driver") Signed-off-by:
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Ryusuke Konishi authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 8301c719 upstream. After commit c3aab9a0 ("mm/filemap.c: don't initiate writeback if mapping has no dirty pages"), the following null pointer dereference has been reported on nilfs2: BUG: kernel NULL pointer dereference, address: 00000000000000a8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI ... RIP: 0010:percpu_counter_add_batch+0xa/0x60 ... Call Trace: __test_set_page_writeback+0x2d3/0x330 nilfs_segctor_do_construct+0x10d3/0x2110 [nilfs2] nilfs_segctor_construct+0x168/0x260 [nilfs2] nilfs_segctor_thread+0x127/0x3b0 [nilfs2] kthread+0xf8/0x130 ... This crash turned out to be caused by set_page_writeback() call for segment summary buffers at nilfs_segctor_prepare_write(). set_page_writeback() can call inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK) where inode_to_wb(inode) is NULL if the inode of underlying block device does not have an associated wb. This fixes the issue by calling inode_attach_wb() in advance to ensure to associate the bdev inode with its wb. Fixes: c3aab9a0 ("mm/filemap.c: don't initiate writeback if mapping has no dirty pages") Reported-by:
Walton Hoops <me@waltonhoops.com> Reported-by:
Tomas Hlavaty <tom@logand.com> Reported-by:
ARAI Shun-ichi <hermes@ceres.dti.ne.jp> Reported-by:
Hideki EIRAKU <hdk1983@gmail.com> Signed-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Tested-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Tejun Heo authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 9b0eb69b upstream. btrfs is going to use css_put() and wbc helpers to improve cgroup writeback support. Add dummy css_get() definition and export wbc helpers to prepare for module and !CONFIG_CGROUP builds. [only backport the export of __inode_attach_wb for stable kernels - gregkh] Reported-by:
kbuild test robot <lkp@intel.com> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
Jens Axboe <axboe@kernel.dk> Signed-off-by:
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Rafael J. Wysocki authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 956ad9d9 upstream. As recently reported, some platforms provide a list of power resources for device power state D3hot, through the _PR3 object, but they do not provide a list of power resources for device power state D0. Among other things, this causes acpi_device_get_power() to return D3hot as the current state of the device in question if all of the D3hot power resources are "on", because it sees the power_resources flag set and calls acpi_power_get_inferred_state() which finds that D3hot is the shallowest power state with all of the associated power resources turned "on", so that's what it returns. Moreover, that value takes precedence over the acpi_dev_pm_explicit_get() return value, because it means a deeper power state. The device may very well be in D0 physically at that point, however. Moreover, the presence of _PR3 without _PR0 for a given device means that only one D3-level power state can be supported by it. Namely, because there are no power resources to turn "off" when transitioning the device from D0 into D3cold (which should be supported since _PR3 is present), the evaluation of _PS3 should be sufficient to put it straight into D3cold, but this means that the effect of turning "on" the _PR3 power resources is unclear, so it is better to avoid doing that altogether. Consequently, there is no practical way do distinguish D3cold from D3hot for the device in question and the power states of it can be labeled so that D3hot is the deepest supported one (and Linux assumes that putting a device into D3hot via ACPI may cause power to be removed from it anyway, for legacy reasons). To work around the problem described above modify the ACPI enumeration of devices so that power resources are only used for device power management if the list of D0 power resources is not empty and make it mart D3cold as supported only if that is the case and the D3hot list of power resources is not empty too. Fixes: ef85bdbe ("ACPI / scan: Consolidate extraction of power resources lists") Link: https://bugzilla.kernel.org/show_bug.cgi?id=205057 Link: https://lore.kernel.org/linux-acpi/20200603194659.185757-1-hdegoede@redhat.com/Reported-by:
Hans de Goede <hdegoede@redhat.com> Tested-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by:
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Qiushi Wu authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 6e6c2528 upstream. kobject_init_and_add() takes reference even when it fails. Thus, when kobject_init_and_add() returns an error, kobject_put() must be called to properly clean up the kobject. Fixes: 3f8055c3 ("ACPI / hotplug: Introduce user space interface for hotplug profiles") Signed-off-by:
Qiushi Wu <wu000273@umn.edu> Cc: 3.10+ <stable@vger.kernel.org> # 3.10+ Signed-off-by:
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Takashi Iwai authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 862b2509 upstream. When a USB-audio interface gets runtime-suspended via auto-pm feature, the driver suspends all functionality and increment chip->num_suspended_intf. Later on, when the system gets suspended to S3, the driver increments chip->num_suspended_intf again, skips the device changes, and sets the card power state to SNDRV_CTL_POWER_D3hot. In return, when the system gets resumed from S3, the resume callback decrements chip->num_suspended_intf. Since this refcount is still not zero (it's been runtime-suspended), the whole resume is skipped. But there is a small pitfall here. The problem is that the driver doesn't restore the card power state after this resume call, leaving it as SNDRV_CTL_POWER_D3hot. So, even after the system resume finishes, the card instance still appears as if it were system-suspended, and this confuses many ioctl accesses that are blocked unexpectedly. In details, we have two issues behind the scene: one is that the card power state is changed only when the refcount becomes zero, and another is that the prior auto-suspend check is kept in a boolean flag. Although the latter problem is almost negligible since the auto-pm feature is imposed only on the primary interface, but this can be a potential problem on the devices with multiple interfaces. This patch addresses those issues by the following: - Replace chip->autosuspended boolean flag with chip->system_suspend counter - At the first system-suspend, chip->num_suspended_intf is recorded to chip->system_suspend - At system-resume, the card power state is restored when the chip->num_suspended_intf refcount reaches to chip->system_suspend, i.e. the state returns to the auto-suspended Also, the patch fixes yet another hidden problem by the code refactoring along with the fixes above: namely, when some resume procedure failed, the driver left chip->num_suspended_intf that was already decreased, and it might lead to the refcount unbalance. In the new code, the refcount decrement is done after the whole resume procedure, and the problem is avoided as well. Fixes: 0662292a ("ALSA: usb-audio: Handle normal and auto-suspend equally") Reported-and-tested-by:
Macpaul Lin <macpaul.lin@mediatek.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200603153709.6293-1-tiwai@suse.deSigned-off-by:
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Chuhong Yuan authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit d9b8fbf1 upstream. snd_es968_pnp_detect() misses a snd_card_free() in a failed path. Add the missed function call to fix it. Fixes: a20971b2 ("ALSA: Merge es1688 and es968 drivers") Signed-off-by:
Chuhong Yuan <hslester96@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200603092459.1424093-1-hslester96@gmail.comSigned-off-by:
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Ard Biesheuvel authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit d8bd8c6e upstream. The documentation provided by kobject_init_and_add() clearly spells out the need to call kobject_put() on the kobject if an error is returned. Add this missing call to the error path. Cc: <stable@vger.kernel.org> Reported-by:
亿一 <teroincn@gmail.com> Signed-off-by:
Ard Biesheuvel <ardb@kernel.org> Signed-off-by:
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Hill Ma authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit 140fd4ac upstream. On MacBook6,1 reboot would hang unless parameter reboot=pci is added. Make it automatic. Signed-off-by:
Hill Ma <maahiuzeon@gmail.com> Signed-off-by:
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Anthony Steinhauser authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit dbbe2ad0 upstream. On context switch the change of TIF_SSBD and TIF_SPEC_IB are evaluated to adjust the mitigations accordingly. This is optimized to avoid the expensive MSR write if not needed. This optimization is buggy and allows an attacker to shutdown the SSBD protection of a victim process. The update logic reads the cached base value for the speculation control MSR which has neither the SSBD nor the STIBP bit set. It then OR's the SSBD bit only when TIF_SSBD is different and requests the MSR update. That means if TIF_SSBD of the previous and next task are the same, then the base value is not updated, even if TIF_SSBD is set. The MSR write is not requested. Subsequently if the TIF_STIBP bit differs then the STIBP bit is updated in the base value and the MSR is written with a wrong SSBD value. This was introduced when the per task/process conditional STIPB switching was added on top of the existing SSBD switching. It is exploitable if the attacker creates a process which enforces SSBD and has the contrary value of STIBP than the victim process (i.e. if the victim process enforces STIBP, the attacker process must not enforce it; if the victim process does not enforce STIBP, the attacker process must enforce it) and schedule it on the same core as the victim process. If the victim runs after the attacker the victim becomes vulnerable to Spectre V4. To fix this, update the MSR value independent of the TIF_SSBD difference and dependent on the SSBD mitigation method available. This ensures that a subsequent STIPB initiated MSR write has the correct state of SSBD. [ tglx: Handle X86_FEATURE_VIRT_SSBD & X86_FEATURE_VIRT_SSBD correctly and massaged changelog ] Fixes: 5bfbe3ad ("x86/speculation: Prepare for per task indirect branch speculation control") Signed-off-by:
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Bob Haarman authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit d8ad6d39 upstream. 'jiffies' and 'jiffies_64' are meant to alias (two different symbols that share the same address). Most architectures make the symbols alias to the same address via a linker script assignment in their arch/<arch>/kernel/vmlinux.lds.S: jiffies = jiffies_64; which is effectively a definition of jiffies. jiffies and jiffies_64 are both forward declared for all architectures in include/linux/jiffies.h. jiffies_64 is defined in kernel/time/timer.c. x86_64 was peculiar in that it wasn't doing the above linker script assignment, but rather was: 1. defining jiffies in arch/x86/kernel/time.c instead via the linker script. 2. overriding the symbol jiffies_64 from kernel/time/timer.c in arch/x86/kernel/vmlinux.lds.s via 'jiffies_64 = jiffies;'. As Fangrui notes: In LLD, symbol assignments in linker scripts override definitions in object files. GNU ld appears to have the same behavior. It would probably make sense for LLD to error "duplicate symbol" but GNU ld is unlikely to adopt for compatibility reasons. This results in an ODR violation (UB), which seems to have survived thus far. Where it becomes harmful is when; 1. -fno-semantic-interposition is used: As Fangrui notes: Clang after LLVM commit 5b22bcc2b70d ("[X86][ELF] Prefer to lower MC_GlobalAddress operands to .Lfoo$local") defaults to -fno-semantic-interposition similar semantics which help -fpic/-fPIC code avoid GOT/PLT when the referenced symbol is defined within the same translation unit. Unlike GCC -fno-semantic-interposition, Clang emits such relocations referencing local symbols for non-pic code as well. This causes references to jiffies to refer to '.Ljiffies$local' when jiffies is defined in the same translation unit. Likewise, references to jiffies_64 become references to '.Ljiffies_64$local' in translation units that define jiffies_64. Because these differ from the names used in the linker script, they will not be rewritten to alias one another. 2. Full LTO Full LTO effectively treats all source files as one translation unit, causing these local references to be produced everywhere. When the linker processes the linker script, there are no longer any references to jiffies_64' anywhere to replace with 'jiffies'. And thus '.Ljiffies$local' and '.Ljiffies_64$local' no longer alias at all. In the process of porting patches enabling Full LTO from arm64 to x86_64, spooky bugs have been observed where the kernel appeared to boot, but init doesn't get scheduled. Avoid the ODR violation by matching other architectures and define jiffies only by linker script. For -fno-semantic-interposition + Full LTO, there is no longer a global definition of jiffies for the compiler to produce a local symbol which the linker script won't ensure aliases to jiffies_64. Fixes: 40747ffa ("asmlinkage: Make jiffies visible") Reported-by:
Nathan Chancellor <natechancellor@gmail.com> Reported-by:
Alistair Delva <adelva@google.com> Debugged-by:
Nick Desaulniers <ndesaulniers@google.com> Debugged-by:
Sami Tolvanen <samitolvanen@google.com> Suggested-by:
Fangrui Song <maskray@google.com> Signed-off-by:
Bob Haarman <inglorion@google.com> Signed-off-by:
Andi Kleen <ak@linux.intel.com> Reviewed-by:
Josh Poimboeuf <jpoimboe@redhat.com> Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/852 Link: https://lkml.kernel.org/r/20200602193100.229287-1-inglorion@google.comSigned-off-by:
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Masashi Honma authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 450edd28 ] Some devices like TP-Link TL-WN722N produces this kind of messages frequently. kernel: ath: phy0: Short RX data len, dropping (dlen: 4) This warning is useful for developers to recognize that the device (Wi-Fi dongle or USB hub etc) is noisy but not for general users. So this patch make this warning to debug message. Reported-By:
Denis <pro.denis@protonmail.com> Ref: https://bugzilla.kernel.org/show_bug.cgi?id=207539 Fixes: cd486e62 ("ath9k_htc: Discard undersized packets") Signed-off-by:
Masashi Honma <masashi.honma@gmail.com> Signed-off-by:
Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20200504214443.4485-1-masashi.honma@gmail.comSigned-off-by:
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Jens Axboe authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 18f855e5 ] Stefano reported a crash with using SQPOLL with io_uring: BUG: kernel NULL pointer dereference, address: 00000000000003b0 CPU: 2 PID: 1307 Comm: io_uring-sq Not tainted 5.7.0-rc7 #11 RIP: 0010:task_numa_work+0x4f/0x2c0 Call Trace: task_work_run+0x68/0xa0 io_sq_thread+0x252/0x3d0 kthread+0xf9/0x130 ret_from_fork+0x35/0x40 which is task_numa_work() oopsing on current->mm being NULL. The task work is queued by task_tick_numa(), which checks if current->mm is NULL at the time of the call. But this state isn't necessarily persistent, if the kthread is using use_mm() to temporarily adopt the mm of a task. Change the task_tick_numa() check to exclude kernel threads in general, as it doesn't make sense to attempt ot balance for kthreads anyway. Reported-by:
Stefano Garzarella <sgarzare@redhat.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org> Acked-by:
Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/865de121-8190-5d30-ece5-3b097dc74431@kernel.dkSigned-off-by:
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Fredrik Strupe authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 3866f217 ] call_undef_hook() in traps.c applies the same instr_mask for both 16-bit and 32-bit thumb instructions. If instr_mask then is only 16 bits wide (0xffff as opposed to 0xffffffff), the first half-word of 32-bit thumb instructions will be masked out. This makes the function match 32-bit thumb instructions where the second half-word is equal to instr_val, regardless of the first half-word. The result in this case is that all undefined 32-bit thumb instructions with the second half-word equal to 0xde01 (udf #1) work as breakpoints and will raise a SIGTRAP instead of a SIGILL, instead of just the one intended 16-bit instruction. An example of such an instruction is 0xeaa0de01, which is unallocated according to Arm ARM and should raise a SIGILL, but instead raises a SIGTRAP. This patch fixes the issue by setting all the bits in instr_mask, which will still match the intended 16-bit thumb instruction (where the upper half is always 0), but not any 32-bit thumb instructions. Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by:
Fredrik Strupe <fredrik@strupe.net> Signed-off-by:
Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by:
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Stefan Agner authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit ad06fdee upstream. Use flat regmap cache to avoid lockdep warning at probe: [ 0.697285] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2755 lockdep_trace_alloc+0x15c/0x160() [ 0.697449] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) The RB-tree regmap cache needs to allocate new space on first writes. However, allocations in an atomic context (e.g. when a spinlock is held) are not allowed. The function regmap_write calls map->lock, which acquires a spinlock in the fast_io case. Since the pwm-fsl-ftm driver uses MMIO, the regmap bus of type regmap_mmio is being used which has fast_io set to true. The MMIO space of the pwm-fsl-ftm driver is reasonable condense, hence using the much faster flat regmap cache is anyway the better choice. Signed-off-by:
Stefan Agner <stefan@agner.ch> Cc: Mark Brown <broonie@kernel.org> Signed-off-by:
Thierry Reding <thierry.reding@gmail.com> Signed-off-by:
Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by:
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Zhao Qiang authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit c505873e upstream. 88E1145 also need this autoneg errata. Fixes: f2899788 ("net: phy: marvell: Limit errata to 88m1101") Signed-off-by:
Zhao Qiang <qiang.zhao@nxp.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by:
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Johannes Thumshirn authored
BugLink: https://bugs.launchpad.net/bugs/1884564 commit e7661a8e upstream. When instrumenting the SCSI layer to run into the !blk_rq_nr_phys_segments(rq) case the following warning emitted from the block layer: blk_peek_request: bad return=-22 This happens because since commit fd3fc0b4 ("scsi: don't BUG_ON() empty DMA transfers") we return the wrong error value from scsi_prep_fn() back to the block layer. [mkp: silenced checkpatch] Signed-off-by:
Johannes Thumshirn <jthumshirn@suse.de> Fixes: fd3fc0b4 scsi: don't BUG_ON() empty DMA transfers Cc: <stable@vger.kernel.org> Reviewed-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Hannes Reinecke <hare@suse.com> Reviewed-by:
Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> [iwamatsu: - backport for 4.4.y and 4.9.y - Use rq->nr_phys_segments instead of blk_rq_nr_phys_segments] Signed-off-by:
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Ido Schimmel authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 8066e6b4 ] When proxy mode is enabled the vxlan device might reply to Neighbor Solicitation (NS) messages on behalf of remote hosts. In case the NS message includes the "Source link-layer address" option [1], the vxlan device will use the specified address as the link-layer destination address in its reply. To avoid an infinite loop, break out of the options parsing loop when encountering an option with length zero and disregard the NS message. This is consistent with the IPv6 ndisc code and RFC 4886 which states that "Nodes MUST silently discard an ND packet that contains an option with length zero" [2]. [1] https://tools.ietf.org/html/rfc4861#section-4.3 [2] https://tools.ietf.org/html/rfc4861#section-4.6 Fixes: 4b29dba9 ("vxlan: fix nonfunctional neigh_reduce()") Signed-off-by:
Ido Schimmel <idosch@mellanox.com> Acked-by:
Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by:
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Hangbin Liu authored
BugLink: https://bugs.launchpad.net/bugs/1884564 [ Upstream commit 79a1f0cc ] Socket option IPV6_ADDRFORM supports UDP/UDPLITE and TCP at present. Previously the checking logic looks like: if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE) do_some_check; else if (sk->sk_protocol != IPPROTO_TCP) break; After commit b6f61189 ("ipv6: restrict IPV6_ADDRFORM operation"), TCP was blocked as the logic changed to: if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE) do_some_check; else if (sk->sk_protocol == IPPROTO_TCP) do_some_check; break; else break; Then after commit 82c9ae44 ("ipv6: fix restrict IPV6_ADDRFORM operation") UDP/UDPLITE were blocked as the logic changed to: if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE) do_some_check; if (sk->sk_protocol == IPPROTO_TCP) do_some_check; if (sk->sk_protocol != IPPROTO_TCP) break; Fix it by using Eric's code and simply remove the break in TCP check, which looks like: if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE) do_some_check; else if (sk->sk_protocol == IPPROTO_TCP) do_some_check; else break; Fixes: 82c9ae44 ("ipv6: fix restrict IPV6_ADDRFORM operation") Signed-off-by:
Hangbin Liu <liuhangbin@gmail.com> Signed-off-by:
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David Howells authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Disallow opening of debugfs files when the kernel is locked down as various drivers give raw access to hardware through debugfs. Accesses to tracefs should use /sys/kernel/tracing/ rather than /sys/kernel/debug/tracing/. Possibly a symlink should be emplaced. Normal device interaction should be done through configfs or a miscdev, not debugfs. Note that this makes it unnecessary to specifically lock down show_dsts(), show_devs() and show_call() in the asus-wmi driver. Signed-off-by:
David Howells <dhowells@redhat.com> cc: Andy Shevchenko <andy.shevchenko@gmail.com> cc: acpi4asus-user@lists.sourceforge.net cc: platform-driver-x86@vger.kernel.org cc: Matthew Garrett <matthew.garrett@nebula.com> cc: Thomas Gleixner <tglx@linutronix.de> (backported from commit 125da2e1c5d0a6aca5faafba336c8e8506a4e000 git://git.kernel.org/pub/scm/linux/kernel/git/jwboyer/fedora.git) Signed-off-by:
Seth Forshee <seth.forshee@canonical.com> Acked-by:
Stefan Bader <stefan.bader@canonical.com> Acked-by:
Andrea Righi <andrea.righi@canonical.com> Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Debugfs' open_proxy_open(), the ->open() installed at all inodes created through debugfs_create_file_unsafe(), - grabs a reference to the original file_operations instance passed to debugfs_create_file_unsafe() via fops_get(), - installs it at the file's ->f_op by means of replace_fops() - and calls fops_put() on it. Since the semantics of replace_fops() are such that the reference's ownership is transferred, the subsequent fops_put() will result in a double release when the file is eventually closed. Currently, this is not an issue since fops_put() basically does a module_put() on the file_operations' ->owner only and there don't exist any modules calling debugfs_create_file_unsafe() yet. This is expected to change in the future though, c.f. commit c6468808 ("debugfs: add support for self-protecting attribute file fops"). Remove the call to fops_put() from open_proxy_open(). Fixes: 9fd4dcec ("debugfs: prevent access to possibly dead file_operations at file open") Signed-off-by:
Nicolai Stange <nicstange@gmail.com> Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Debugfs' full_proxy_open(), the ->open() installed at all inodes created through debugfs_create_file(), - grabs a reference to the original struct file_operations instance passed to debugfs_create_file(), - dynamically allocates a proxy struct file_operations instance wrapping the original - and installs this at the file's ->f_op. Afterwards, it calls the original ->open() and passes its return value back to the VFS layer. Now, if that return value indicates failure, the VFS layer won't ever call ->release() and thus, neither the reference to the original file_operations nor the memory for the proxy file_operations will get released, i.e. both are leaked. Upon failure of the original fops' ->open(), undo the proxy installation. That is: - Set the struct file ->f_op to what it had been when full_proxy_open() was entered. - Drop the reference to the original file_operations. - Free the memory holding the proxy file_operations. Fixes: 49d200de ("debugfs: prevent access to removed files' private data") Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 The struct file_operations u32_array_fops associated with files created through debugfs_create_u32_array() has been lifetime aware already: everything needed for subsequent operation is copied to a ->f_private buffer at file opening time in u32_array_open(). Now, ->open() is always protected against file removal issues by the debugfs core. There is no need for the debugfs core to wrap the u32_array_fops with a file lifetime managing proxy. Make debugfs_create_u32_array() create its files in non-proxying operation mode by means of debugfs_create_file_unsafe(). Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Currently, the struct file_operations fops_blob associated with files created through the debugfs_create_blob() helpers are not file lifetime aware. Thus, a lifetime managing proxy is created around fops_blob each time such a file is opened which is an unnecessary waste of resources. Implement file lifetime management for the fops_bool file_operations. Namely, make read_file_blob() safe gainst file removals by means of debugfs_use_file_start() and debugfs_use_file_finish(). Make debugfs_create_blob() create its files in non-proxying operation mode by means of debugfs_create_file_unsafe(). Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Currently, the struct file_operations fops_bool associated with files created through the debugfs_create_bool() helpers are not file lifetime aware. Thus, a lifetime managing proxy is created around fops_bool each time such a file is opened which is an unnecessary waste of resources. Implement file lifetime management for the fops_bool file_operations. Namely, make debugfs_read_file_bool() and debugfs_write_file_bool() safe against file removals by means of debugfs_use_file_start() and debugfs_use_file_finish(). Make debugfs_create_bool() create its files in non-proxying operation mode through debugfs_create_mode_unsafe(). Finally, purge debugfs_create_mode() as debugfs_create_bool() had been its last user. Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Currently, the struct file_operations associated with the integer attribute style files created through the debugfs_create_*() helpers are not file lifetime aware as they are defined by means of DEFINE_SIMPLE_ATTRIBUTE(). Thus, a lifetime managing proxy is created around the original fops each time such a file is opened which is an unnecessary waste of resources. Migrate all usages of DEFINE_SIMPLE_ATTRIBUTE() within debugfs itself to DEFINE_DEBUGFS_ATTRIBUTE() in order to implement file lifetime managing within the struct file_operations thus defined. Introduce the debugfs_create_mode_unsafe() helper, analogous to debugfs_create_mode(), but distinct in that it creates the files in non-proxying operation mode through debugfs_create_file_unsafe(). Feed all struct file_operations migrated to DEFINE_DEBUGFS_ATTRIBUTE() into debugfs_create_mode_unsafe() instead of former debugfs_create_mode(). Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 In order to protect them against file removal issues, debugfs_create_file() creates a lifetime managing proxy around each struct file_operations handed in. In cases where this struct file_operations is able to manage file lifetime by itself already, the proxy created by debugfs is a waste of resources. The most common class of struct file_operations given to debugfs are those defined by means of the DEFINE_SIMPLE_ATTRIBUTE() macro. Introduce a DEFINE_DEBUGFS_ATTRIBUTE() macro to allow any struct file_operations of this class to be easily made file lifetime aware and thus, to be operated unproxied. Specifically, introduce debugfs_attr_read() and debugfs_attr_write() which wrap simple_attr_read() and simple_attr_write() under the protection of a debugfs_use_file_start()/debugfs_use_file_finish() pair. Make DEFINE_DEBUGFS_ATTRIBUTE() set the defined struct file_operations' ->read() and ->write() members to these wrappers. Export debugfs_create_file_unsafe() in order to allow debugfs users to create their files in non-proxying operation mode. Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Upon return of debugfs_remove()/debugfs_remove_recursive(), it might still be attempted to access associated private file data through previously opened struct file objects. If that data has been freed by the caller of debugfs_remove*() in the meanwhile, the reading/writing process would either encounter a fault or, if the memory address in question has been reassigned again, unrelated data structures could get overwritten. However, since debugfs files are seldomly removed, usually from module exit handlers only, the impact is very low. Currently, there are ~1000 call sites of debugfs_create_file() spread throughout the whole tree and touching all of those struct file_operations in order to make them file removal aware by means of checking the result of debugfs_use_file_start() from within their methods is unfeasible. Instead, wrap the struct file_operations by a lifetime managing proxy at file open: - In debugfs_create_file(), the original fops handed in has got stashed away in ->d_fsdata already. - In debugfs_create_file(), install a proxy file_operations factory, debugfs_full_proxy_file_operations, at ->i_fop. This proxy factory has got an ->open() method only. It carries out some lifetime checks and if successful, dynamically allocates and sets up a new struct file_operations proxy at ->f_op. Afterwards, it forwards to the ->open() of the original struct file_operations in ->d_fsdata, if any. The dynamically set up proxy at ->f_op has got a lifetime managing wrapper set for each of the methods defined in the original struct file_operations in ->d_fsdata. Its ->release()er frees the proxy again and forwards to the original ->release(), if any. In order not to mislead the VFS layer, it is strictly necessary to leave those fields blank in the proxy that have been NULL in the original struct file_operations also, i.e. aren't supported. This is why there is a need for dynamically allocated proxies. The choice made not to allocate a proxy instance for every dentry at file creation, but for every struct file object instantiated thereof is justified by the expected usage pattern of debugfs, namely that in general very few files get opened more than once at a time. The wrapper methods set in the struct file_operations implement lifetime managing by means of the SRCU protection facilities already in place for debugfs: They set up a SRCU read side critical section and check whether the dentry is still alive by means of debugfs_use_file_start(). If so, they forward the call to the original struct file_operation stored in ->d_fsdata, still under the protection of the SRCU read side critical section. This SRCU read side critical section prevents any pending debugfs_remove() and friends to return to their callers. Since a file's private data must only be freed after the return of debugfs_remove(), the ongoing proxied call is guarded against any file removal race. If, on the other hand, the initial call to debugfs_use_file_start() detects that the dentry is dead, the wrapper simply returns -EIO and does not forward the call. Note that the ->poll() wrapper is special in that its signature does not allow for the return of arbitrary -EXXX values and thus, POLLHUP is returned here. In order not to pollute debugfs with wrapper definitions that aren't ever needed, I chose not to define a wrapper for every struct file_operations method possible. Instead, a wrapper is defined only for the subset of methods which are actually set by any debugfs users. Currently, these are: ->llseek() ->read() ->write() ->unlocked_ioctl() ->poll() The ->release() wrapper is special in that it does not protect the original ->release() in any way from dead files in order not to leak resources. Thus, any ->release() handed to debugfs must implement file lifetime management manually, if needed. For only 33 out of a total of 434 releasers handed in to debugfs, it could not be verified immediately whether they access data structures that might have been freed upon a debugfs_remove() return in the meanwhile. Export debugfs_use_file_start() and debugfs_use_file_finish() in order to allow any ->release() to manually implement file lifetime management. For a set of common cases of struct file_operations implemented by the debugfs_core itself, future patches will incorporate file lifetime management directly within those in order to allow for their unproxied operation. Rename the original, non-proxying "debugfs_create_file()" to "debugfs_create_file_unsafe()" and keep it for future internal use by debugfs itself. Factor out code common to both into the new __debugfs_create_file(). Signed-off-by:
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Nicolai Stange authored
BugLink: https://bugs.launchpad.net/bugs/1884159 Nothing prevents a dentry found by path lookup before a return of __debugfs_remove() to actually get opened after that return. Now, after the return of __debugfs_remove(), there are no guarantees whatsoever regarding the memory the corresponding inode's file_operations object had been kept in. Since __debugfs_remove() is seldomly invoked, usually from module exit handlers only, the race is hard to trigger and the impact is very low. A discussion of the problem outlined above as well as a suggested solution can be found in the (sub-)thread rooted at http://lkml.kernel.org/g/20130401203445.GA20862@ZenIV.linux.org.uk ("Yet another pipe related oops.") Basically, Greg KH suggests to introduce an intermediate fops and Al Viro points out that a pointer to the original ones may be stored in ->d_fsdata. Follow this line of reasoning: - Add SRCU as a reverse dependency of DEBUG_FS. - Introduce a srcu_struct object for the debugfs subsystem. - In debugfs_create_file(), store a pointer to the original file_operations object in ->d_fsdata. - Make debugfs_remove() and debugfs_remove_recursive() wait for a SRCU grace period after the dentry has been delete()'d and before they return to their callers. - Introduce an intermediate file_operations object named "debugfs_open_proxy_file_operations". It's ->open() functions checks, under the protection of a SRCU read lock, whether the dentry is still alive, i.e. has not been d_delete()'d and if so, tries to acquire a reference on the owning module. On success, it sets the file object's ->f_op to the original file_operations and forwards the ongoing open() call to the original ->open(). - For clarity, rename the former debugfs_file_operations to debugfs_noop_file_operations -- they are in no way canonical. The choice of SRCU over "normal" RCU is justified by the fact, that the former may also be used to protect ->i_private data from going away during the execution of a file's readers and writers which may (and do) sleep. Finally, introduce the fs/debugfs/internal.h header containing some declarations internal to the debugfs implementation. Signed-off-by:
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