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* w1_therm: adding alarm sysfs entryAkira Shimahara2020-05-152-0/+177
| | | | | | | | | | | | | | | | | | | | Adding device alarms settings by a dedicated sysfs entry alarms (RW): read or write TH and TL in the device RAM. Checking devices in alarm state could be performed using the master search command. As alarms temperature level are store in a 8 bit register on the device and are signed values, a safe cast shall be performed using the min and max temperature that device are able to measure. This is done by int_to_short inline function. A 'write_data' field is added in the device structure, to bind the correct writing function, as some devices may have 2 or 3 bytes RAM. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203801.411253-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: optimizing temperature read timingsAkira Shimahara2020-05-152-101/+197
| | | | | | | | | | | | | | | | | | | | | | | | | | Optimizing temperature reading by reducing waiting conversion time according to device resolution settings, as per device specification. This is device dependent as not all the devices supports resolution setting, so it has been added in device family structures. The process to read the temperature on the device has been adapted in a new function 'convert_t()', which replace the former 'read_therm()', is introduce to deal with this timing. Strong pull up is also applied during the required time, according to device power status needs and 'strong_pullup' module parameter. 'temperature_from_RAM()' function is introduced to get the correct temperature computation (device dependent) from device RAM data. An new sysfs entry has been added to ouptut only temperature. The old entry w1_slave has been kept for compatibility, without changing its output format. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203742.411039-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: adding eeprom sysfs entryAkira Shimahara2020-05-152-57/+132
| | | | | | | | | | | | | | | | | The driver implement 2 hardware functions to access device RAM: * copy_scratchpad * recall_scratchpad They act according to device specifications. As EEPROM operations are not device dependent (all w1_therm can perform EEPROM read/write operation following the same protocol), it is removed from device families structures. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203725.410844-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: adding resolution sysfs entryAkira Shimahara2020-05-152-98/+361
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding resolution sysfs entry (RW) to get or set the device resolution Write values are managed as follow: * '9..12': resolution to set in bit * Anything else: do nothing Read values are : * '9..12': device resolution in bit * '-xx': xx is kernel error when reading the resolution Only supported devices will show the sysfs entry. A new family has been created for DS18S20 devices as they do not implement resolution feature. The resolution of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the resolution of each device, which could be used later to determine the required conversion duration (resolution dependent). The resolution is re evaluate each time a user read or write the sysfs entry. To avoid looping through the w1_therm_families at run time, the pointer 'specific_functions' is set up to the correct 'w1_therm_family_converter' when the slave is added (which mean when it is discovered by the master). This initialization is done by a helper function 'device_family(struct w1_slave *sl)', and a dedicated macro 'SLAVE_SPECIFIC_FUNC(sl)' allow the access to the specific function of the slave device. 'read_scratchpad' and 'write_scratchpad' are the hardware functions to access the device RAM, as per protocol specification. It cancel the former 'precision' functions, which was only set and never read (so not stored in the device struct). Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203708.410649-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: adding ext_power sysfs entryAkira Shimahara2020-05-152-0/+149
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding ext_power sysfs entry (RO). Return the power status of the device: - 0: device parasite powered - 1: device externally powered - xx: xx is kernel error The power status of each device is check when the device is discover by the bus master, in 'w1_therm_add_slave(struct w1_slave *)'. The status is stored in the device structure w1_therm_family_data so that the driver always knows the power state of each device, which could be used later to determine the required strong pull up to apply on the line. The power status is re evaluate each time the sysfs ext_power read by a user. The hardware function 'read_powermode(struct w1_slave *sl)' act just as per device specifications, sending W1_READ_PSUPPLY command on the bus, and issue a read time slot, reading only one bit. A helper function 'bool bus_mutex_lock(struct mutex *lock)' is introduced. It try to aquire the bus mutex several times (W1_THERM_MAX_TRY), waiting W1_THERM_RETRY_DELAY between two attempt. Updating Documentation/ABI/testing/sysfs-driver-w1_therm accordingly. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203650.410439-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: adding sysfs-driver-w1_therm docAkira Shimahara2020-05-151-0/+17
| | | | | | | | | | Adding a sysfs-driver-w1_therm documentation file in Documentation/ABI/testing. It describe the onlys sysfs entry of w1_therm module, based on Documentation/w1/slaves/w1_therm.rst Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203631.410227-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: fix reset_select_slave during discoveryAkira Shimahara2020-05-151-7/+41
| | | | | | | | | | | | | | | | | | | | | Fix reset_select_slave issue during devices discovery by the master on bus. The w1_reset_select_slave() from w1_io.c, which was previously used, assume that if the slave count is 1 there is only one slave attached on the bus. This is not always true. For example when discovering devices, when the first device is discover by the bus master, its slave count is 1, but some other slaves may be on the bus. In that case instead of adressing command to the attached slave the master throw a SKIP ROM command so that all slaves attached on the bus will answer simultenaously causing data collision. A dedicated reset_select_slave() function is implemented here, it always perform an adressing to each slave using the MATCH ROM command. Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203610.409975-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1_therm: adding code comments and code reorderingAkira Shimahara2020-05-151-168/+259
| | | | | | | | | | | | | | | Adding code comments to split code in dedicated parts. After the global declarations (defines, macros and function declarations), code is organized as follow : - Device and family dependent structures and functions - Interfaces functions - Helpers functions - Hardware functions - Sysfs interface functions Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203535.409599-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* VMCI: Avoid extra check for access_ok()Souptick Joarder2020-05-151-2/+0
| | | | | | | | | get_user_pages_fast() is already having a check for the same. This double check can be removed. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Link: https://lore.kernel.org/r/1588709912-8065-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dca: Use PTR_ERR_OR_ZERO() to simplify codeTang Bin2020-05-151-3/+1
| | | | | | | | | | The function PTR_ERR_OR_ZERO() contains the check of IS_ERR() and the return of PTR_ERR() or zero. Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com> Link: https://lore.kernel.org/r/20200507111224.4176-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: ds2430: fix eeprom size in driver descriptionAngelo Dureghello2020-05-151-1/+1
| | | | | | | | Non functional fix, set Kb to b, to avoid any misundertanding. Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com> Link: https://lore.kernel.org/r/20200507195050.472483-1-angelo.dureghello@timesys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: fastrpc: fix potential fastrpc_invoke_ctx leakSrinivas Kandagatla2020-05-151-1/+8
| | | | | | | | | | | | | | | | | | fastrpc_invoke_ctx can have refcount of 2 in error path where rpmsg_send() fails to send invoke message. decrement the refcount properly in the error path to fix this leak. This also fixes below static checker warning: drivers/misc/fastrpc.c:990 fastrpc_internal_invoke() warn: 'ctx->refcount.refcount.ref.counter' not decremented on lines: 990. Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Link: https://lore.kernel.org/r/20200512110930.2550-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: fastrpc: Fix an incomplete memory release in fastrpc_rpmsg_probe()Srinivas Kandagatla2020-05-151-1/+3
| | | | | | | | | | | | fastrpc_channel_ctx is not freed if misc_register() fails, this would lead to a memory leak. Fix this leak by adding kfree in misc_register() error path. Fixes: 278d56f970ae ("misc: fastrpc: Reference count channel context") Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Link: https://lore.kernel.org/r/20200511162722.2552-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* slimbus: core: Fix mismatch in of_node_get/putSaravana Kannan2020-05-151-0/+1
| | | | | | | | | | | Adding missing corresponding of_node_put Fixes: 7588a511bdb4 ("slimbus: core: add support to device tree helper") Signed-off-by: Saravana Kannan <saravanak@google.com> [Srini: added fixes tag, removed NULL check and updated log] Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200511151334.362-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* slimbus: core: Set fwnode for a device when setting of_nodeSaravana Kannan2020-05-151-3/+2
| | | | | | | | | | | | | | When setting the of_node for a newly created device, also set the fwnode. This allows fw_devlink feature to work for slimbus devices. Also, remove some unnecessary NULL checks. The functions in question already do NULL checks. Signed-off-by: Saravana Kannan <saravanak@google.com> [Srini: removed unnecessary NULL check from other patch] Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200511151334.362-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* nvmem: jz4780-efuse: Use PTR_ERR_OR_ZERO() to simplify codeSamuel Zou2020-05-151-3/+1
| | | | | | | | | | | | Fixes coccicheck warning: drivers/nvmem/jz4780-efuse.c:214:1-3: WARNING: PTR_ERR_OR_ZERO can be used Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Samuel Zou <zou_wei@huawei.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200511145042.31223-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* nvmem: ensure sysfs writes handle write-protect pinMichael Auchter2020-05-151-26/+26
| | | | | | | | | | | | | | | | | | | | | | Commit 2a127da461a9 ("nvmem: add support for the write-protect pin") added support for handling write-protect pins to the nvmem core, and Commit 1c89074bf850 ("eeprom: at24: remove the write-protect pin support") retrofitted the at24 driver to use this support. These changes broke write() on the nvmem sysfs attribute for eeproms which utilize a write-protect pin, as the write callback invokes the nvmem device's reg_write callback directly which no longer handles changing the state of the write-protect pin. Change the read and write callbacks for the sysfs attribute to invoke nvmme_reg_read/nvmem_reg_write helpers which handle this, rather than calling reg_read/reg_write directly. Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin") Signed-off-by: Michael Auchter <michael.auchter@ni.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200511145042.31223-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* nvmem: imx-ocotp: Improve logic to save many code linesAnson Huang2020-05-151-7/+2
| | | | | | | | | | | | | Several logic improvements to save many code lines: - no need to use goto; - no need to assign return value; - combine different conditions of return value into one line. Signed-off-by: Anson Huang <Anson.Huang@nxp.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200511145042.31223-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* firmware: xilinx: Fix an error handling path in 'zynqmp_firmware_probe()'Christophe JAILLET2020-05-151-2/+2
| | | | | | | | | | | | | | If 'mfd_add_devices()' fails, we must undo 'zynqmp_pm_api_debugfs_init()' otherwise some debugfs directory and files will be left. Just move the call to 'zynqmp_pm_api_debugfs_init()' a few lines below to fix the issue. Fixes: e23d9c6d0d49 ("drivers: soc: xilinx: Add ZynqMP power domain driver") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Jolly Shah <jolly.shah@xilinx.com> Link: https://lore.kernel.org/r/20200510130357.233364-1-christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: xilinx-sdfec: convert to module_platform_driver()Harshal Chaudhari2020-05-151-19/+1
| | | | | | | | | | | The driver init and exit function don't do anything besides registering and unregistering the platform driver, so the module_platform_driver() macro could just be used instead of having separate functions. Signed-off-by: Harshal Chaudhari <harshalchau04@gmail.com> Acked-by: Dragan Cvetic <dragan.cvetic@xilinx.com> Link: https://lore.kernel.org/r/20200510164308.31358-1-harshalchau04@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* uio_hv_generic: add missed sysfs_remove_bin_fileChuhong Yuan2020-05-151-0/+1
| | | | | | | | | | This driver calls sysfs_create_bin_file() in probe, but forgets to call sysfs_remove_bin_file() in remove. Add the missed call to fix it. Signed-off-by: Chuhong Yuan <hslester96@gmail.com> Link: https://lore.kernel.org/r/20200507151343.792816-1-hslester96@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'fpga-for-5.8' of ↵Greg Kroah-Hartman2020-05-1510-40/+100
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga into char-misc-next Moritz writes: FPGA Manager changes for 5.8 Here's the first set of changes for the 5.8-rc1 merge window. Dominic's change adds support for accessing AFU regions with gdb. Gustavo's change is a cleanup patch regarding variable lenght arrays. Richard's changes update dt-bindings and add support for stratix and agilex. Sergiu's changes update spi transfers with the new delay field. Xu's change addresses an issue with a wrong return value. Shubhrajyoti's change makes the Zynq FPGA driver return -EPROBE_DEFER on check of devm_clk_get failure. Xu's change for DFL enables multiple opens. All of these patches have been reviewed, have appropriate Acked-by's and have been in the last few linux-next releases without issues. Signed-off-by: Moritz Fischer <mdf@kernel.org> * tag 'fpga-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga: fpga: dfl: afu: support debug access to memory-mapped afu regions fpga: dfl.h: Replace zero-length array with flexible-array member arm64: dts: agilex: correct service layer driver's compatible value dt-bindings, firmware: add compatible value Intel Stratix10 service layer binding fpga: stratix10-soc: add compatible property value for intel agilex arm64: dts: agilex: correct FPGA manager driver's compatible value dt-bindings: fpga: add compatible value to Stratix10 SoC FPGA manager binding fpga: machxo2-spi: Use new structure for SPI transfer delays fpga: ice40-spi: Use new structure for SPI transfer delays fpga: dfl: support multiple opens on feature device node.
| * fpga: dfl: afu: support debug access to memory-mapped afu regionsDominic Chen2020-04-291-0/+9
| | | | | | | | | | | | | | | | Allow debug access to memory-mapped regions using e.g. gdb. Signed-off-by: Dominic Chen <d.c.ddcc@gmail.com> Acked-by: Wu Hao <hao.wu@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * fpga: dfl.h: Replace zero-length array with flexible-array memberGustavo A. R. Silva2020-04-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * arm64: dts: agilex: correct service layer driver's compatible valueRichard Gong2020-04-291-1/+1
| | | | | | | | | | | | | | | | Correct the compatible property value for Intel Service Layer driver on Intel Agilex SoC platform. Signed-off-by: Richard Gong <richard.gong@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * dt-bindings, firmware: add compatible value Intel Stratix10 service layer ↵Richard Gong2020-04-291-1/+1
| | | | | | | | | | | | | | | | | | | | binding A a compatible property value to Intel Stratix10 service layer binding Signed-off-by: Richard Gong <richard.gong@intel.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * fpga: stratix10-soc: add compatible property value for intel agilexRichard Gong2020-04-291-1/+2
| | | | | | | | | | | | | | | | Add compatible property value so we can reuse FPGA manager driver on Intel Agilex SoC platform. Signed-off-by: Richard Gong <richard.gong@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * arm64: dts: agilex: correct FPGA manager driver's compatible valueRichard Gong2020-04-291-1/+1
| | | | | | | | | | | | | | | | Correct the compatible property value for FPGA manager driver on Intel Agilex SoC platform. Signed-off-by: Richard Gong <richard.gong@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * dt-bindings: fpga: add compatible value to Stratix10 SoC FPGA manager bindingRichard Gong2020-04-291-1/+2
| | | | | | | | | | | | | | | | Add a compatible property value to Stratix10 SoC FPGA manager binding file Signed-off-by: Richard Gong <richard.gong@intel.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * fpga: machxo2-spi: Use new structure for SPI transfer delaysSergiu Cuciurean2020-04-291-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In a recent change to the SPI subsystem [1], a new `delay` struct was added to replace the `delay_usecs`. This change replaces the current `delay_usecs` with `delay` for this driver. The `spi_transfer_delay_exec()` function [in the SPI framework] makes sure that both `delay_usecs` & `delay` are used (in this order to preserve backwards compatibility). [1] commit bebcfd272df6 ("spi: introduce `delay` field for `spi_transfer` + spi_transfer_delay_exec()") Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * fpga: ice40-spi: Use new structure for SPI transfer delaysSergiu Cuciurean2020-04-291-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In a recent change to the SPI subsystem [1], a new `delay` struct was added to replace the `delay_usecs`. This change replaces the current `delay_usecs` with `delay` for this driver. The `spi_transfer_delay_exec()` function [in the SPI framework] makes sure that both `delay_usecs` & `delay` are used (in this order to preserve backwards compatibility). [1] commit bebcfd272df6 ("spi: introduce `delay` field for `spi_transfer` + spi_transfer_delay_exec()") Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
| * fpga: dfl: support multiple opens on feature device node.Xu Yilun2020-04-294-28/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each DFL functional block, e.g. AFU (Accelerated Function Unit) and FME (FPGA Management Engine), could implement more than one function within its region, but current driver only allows one user application to access it by exclusive open on device node. So this is not convenient and flexible for userspace applications, as they have to combine lots of different functions into one single application. This patch removes the limitation here to allow multiple opens to each feature device node for AFU and FME from userspace applications. If user still needs exclusive access to these device node, O_EXCL flag must be issued together with open. Signed-off-by: Wu Hao <hao.wu@intel.com> Signed-off-by: Xu Yilun <yilun.xu@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
* | greybus: Replace zero-length array with flexible-arrayGustavo A. R. Silva2020-05-132-23/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200507185318.GA14393@embeddedor Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge 5.7-rc5 into char-misc-nextGreg Kroah-Hartman2020-05-11461-2037/+4386
|\ \ | | | | | | | | | | | | | | | We want the char-misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | Linux 5.7-rc5v5.7-rc5Linus Torvalds2020-05-101-1/+1
| | |
| * | Merge tag 'x86-urgent-2020-05-10' of ↵Linus Torvalds2020-05-1011-90/+138
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of fixes for x86: - Ensure that direct mapping alias is always flushed when changing page attributes. The optimization for small ranges failed to do so when the virtual address was in the vmalloc or module space. - Unbreak the trace event registration for syscalls without arguments caused by the refactoring of the SYSCALL_DEFINE0() macro. - Move the printk in the TSC deadline timer code to a place where it is guaranteed to only be called once during boot and cannot be rearmed by clearing warn_once after boot. If it's invoked post boot then lockdep rightfully complains about a potential deadlock as the calling context is different. - A series of fixes for objtool and the ORC unwinder addressing variety of small issues: - Stack offset tracking for indirect CFAs in objtool ignored subsequent pushs and pops - Repair the unwind hints in the register clearing entry ASM code - Make the unwinding in the low level exit to usermode code stop after switching to the trampoline stack. The unwind hint is no longer valid and the ORC unwinder emits a warning as it can't find the registers anymore. - Fix unwind hints in switch_to_asm() and rewind_stack_do_exit() which caused objtool to generate bogus ORC data. - Prevent unwinder warnings when dumping the stack of a non-current task as there is no way to be sure about the validity because the dumped stack can be a moving target. - Make the ORC unwinder behave the same way as the frame pointer unwinder when dumping an inactive tasks stack and do not skip the first frame. - Prevent ORC unwinding before ORC data has been initialized - Immediately terminate unwinding when a unknown ORC entry type is found. - Prevent premature stop of the unwinder caused by IRET frames. - Fix another infinite loop in objtool caused by a negative offset which was not catched. - Address a few build warnings in the ORC unwinder and add missing static/ro_after_init annotations" * tag 'x86-urgent-2020-05-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/unwind/orc: Move ORC sorting variables under !CONFIG_MODULES x86/apic: Move TSC deadline timer debug printk ftrace/x86: Fix trace event registration for syscalls without arguments x86/mm/cpa: Flush direct map alias during cpa objtool: Fix infinite loop in for_offset_range() x86/unwind/orc: Fix premature unwind stoppage due to IRET frames x86/unwind/orc: Fix error path for bad ORC entry type x86/unwind/orc: Prevent unwinding before ORC initialization x86/unwind/orc: Don't skip the first frame for inactive tasks x86/unwind: Prevent false warnings for non-current tasks x86/unwind/orc: Convert global variables to static x86/entry/64: Fix unwind hints in rewind_stack_do_exit() x86/entry/64: Fix unwind hints in __switch_to_asm() x86/entry/64: Fix unwind hints in kernel exit path x86/entry/64: Fix unwind hints in register clearing code objtool: Fix stack offset tracking for indirect CFAs
| | * | x86/unwind/orc: Move ORC sorting variables under !CONFIG_MODULESJosh Poimboeuf2020-05-031-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following warnings seen with !CONFIG_MODULES: arch/x86/kernel/unwind_orc.c:29:26: warning: 'cur_orc_table' defined but not used [-Wunused-variable] 29 | static struct orc_entry *cur_orc_table = __start_orc_unwind; | ^~~~~~~~~~~~~ arch/x86/kernel/unwind_orc.c:28:13: warning: 'cur_orc_ip_table' defined but not used [-Wunused-variable] 28 | static int *cur_orc_ip_table = __start_orc_unwind_ip; | ^~~~~~~~~~~~~~~~ Fixes: 153eb2223c79 ("x86/unwind/orc: Convert global variables to static") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linux Next Mailing List <linux-next@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200428071640.psn5m7eh3zt2in4v@treble
| | * | x86/apic: Move TSC deadline timer debug printkThomas Gleixner2020-05-011-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Leon reported that the printk_once() in __setup_APIC_LVTT() triggers a lockdep splat due to a lock order violation between hrtimer_base::lock and console_sem, when the 'once' condition is reset via /sys/kernel/debug/clear_warn_once after boot. The initial printk cannot trigger this because that happens during boot when the local APIC timer is set up on the boot CPU. Prevent it by moving the printk to a place which is guaranteed to be only called once during boot. Mark the deadline timer check related functions and data __init while at it. Reported-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/87y2qhoshi.fsf@nanos.tec.linutronix.de
| | * | ftrace/x86: Fix trace event registration for syscalls without argumentsKonstantin Khlebnikov2020-05-011-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The refactoring of SYSCALL_DEFINE0() macros removed the ABI stubs and simply defines __abi_sys_$NAME as alias of __do_sys_$NAME. As a result kallsyms_lookup() returns "__do_sys_$NAME" which does not match with the declared trace event name. See also commit 1c758a2202a6 ("tracing/x86: Update syscall trace events to handle new prefixed syscall func names"). Add __do_sys_ to the valid prefixes which are checked in arch_syscall_match_sym_name(). Fixes: d2b5de495ee9 ("x86/entry: Refactor SYSCALL_DEFINE0 macros") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/158636958997.7900.16485049455470033557.stgit@buzz
| | * | x86/mm/cpa: Flush direct map alias during cpaRick Edgecombe2020-04-301-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As an optimization, cpa_flush() was changed to optionally only flush the range in @cpa if it was small enough. However, this range does not include any direct map aliases changed in cpa_process_alias(). So small set_memory_() calls that touch that alias don't get the direct map changes flushed. This situation can happen when the virtual address taking variants are passed an address in vmalloc or modules space. In these cases, force a full TLB flush. Note this issue does not extend to cases where the set_memory_() calls are passed a direct map address, or page array, etc, as the primary target. In those cases the direct map would be flushed. Fixes: 935f5839827e ("x86/mm/cpa: Optimize cpa_flush_array() TLB invalidation") Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200424105343.GA20730@hirez.programming.kicks-ass.net
| | * | objtool: Fix infinite loop in for_offset_range()Josh Poimboeuf2020-04-261-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Randy reported that objtool got stuck in an infinite loop when processing drivers/i2c/busses/i2c-parport.o. It was caused by the following code: 00000000000001fd <line_set>: 1fd: 48 b8 00 00 00 00 00 movabs $0x0,%rax 204: 00 00 00 1ff: R_X86_64_64 .rodata-0x8 207: 41 55 push %r13 209: 41 89 f5 mov %esi,%r13d 20c: 41 54 push %r12 20e: 49 89 fc mov %rdi,%r12 211: 55 push %rbp 212: 48 89 d5 mov %rdx,%rbp 215: 53 push %rbx 216: 0f b6 5a 01 movzbl 0x1(%rdx),%ebx 21a: 48 8d 34 dd 00 00 00 lea 0x0(,%rbx,8),%rsi 221: 00 21e: R_X86_64_32S .rodata 222: 48 89 f1 mov %rsi,%rcx 225: 48 29 c1 sub %rax,%rcx find_jump_table() saw the .rodata reference and tried to find a jump table associated with it (though there wasn't one). The -0x8 rela addend is unusual. It caused find_jump_table() to send a negative table_offset (unsigned 0xfffffffffffffff8) to find_rela_by_dest(). The negative offset should have been harmless, but it actually threw for_offset_range() for a loop... literally. When the mask value got incremented past the end value, it also wrapped to zero, causing the loop exit condition to remain true forever. Prevent this scenario from happening by ensuring the incremented value is always >= the starting value. Fixes: 74b873e49d92 ("objtool: Optimize find_rela_by_dest_range()") Reported-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Julien Thierry <jthierry@redhat.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/02b719674b031800b61e33c30b2e823183627c19.1587842122.git.jpoimboe@redhat.com
| | * | x86/unwind/orc: Fix premature unwind stoppage due to IRET framesJosh Poimboeuf2020-04-253-14/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following execution path is possible: fsnotify() [ realign the stack and store previous SP in R10 ] <IRQ> [ only IRET regs saved ] common_interrupt() interrupt_entry() <NMI> [ full pt_regs saved ] ... [ unwind stack ] When the unwinder goes through the NMI and the IRQ on the stack, and then sees fsnotify(), it doesn't have access to the value of R10, because it only has the five IRET registers. So the unwind stops prematurely. However, because the interrupt_entry() code is careful not to clobber R10 before saving the full regs, the unwinder should be able to read R10 from the previously saved full pt_regs associated with the NMI. Handle this case properly. When encountering an IRET regs frame immediately after a full pt_regs frame, use the pt_regs as a backup which can be used to get the C register values. Also, note that a call frame resets the 'prev_regs' value, because a function is free to clobber the registers. For this fix to work, the IRET and full regs frames must be adjacent, with no FUNC frames in between. So replace the FUNC hint in interrupt_entry() with an IRET_REGS hint. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/97a408167cc09f1cfa0de31a7b70dd88868d743f.1587808742.git.jpoimboe@redhat.com
| | * | x86/unwind/orc: Fix error path for bad ORC entry typeJosh Poimboeuf2020-04-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the ORC entry type is unknown, nothing else can be done other than reporting an error. Exit the function instead of breaking out of the switch statement. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/a7fa668ca6eabbe81ab18b2424f15adbbfdc810a.1587808742.git.jpoimboe@redhat.com
| | * | x86/unwind/orc: Prevent unwinding before ORC initializationJosh Poimboeuf2020-04-251-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the unwinder is called before the ORC data has been initialized, orc_find() returns NULL, and it tries to fall back to using frame pointers. This can cause some unexpected warnings during boot. Move the 'orc_init' check from orc_find() to __unwind_init(), so that it doesn't even try to unwind from an uninitialized state. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/069d1499ad606d85532eb32ce39b2441679667d5.1587808742.git.jpoimboe@redhat.com
| | * | x86/unwind/orc: Don't skip the first frame for inactive tasksMiroslav Benes2020-04-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When unwinding an inactive task, the ORC unwinder skips the first frame by default. If both the 'regs' and 'first_frame' parameters of unwind_start() are NULL, 'state->sp' and 'first_frame' are later initialized to the same value for an inactive task. Given there is a "less than or equal to" comparison used at the end of __unwind_start() for skipping stack frames, the first frame is skipped. Drop the equal part of the comparison and make the behavior equivalent to the frame pointer unwinder. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/7f08db872ab59e807016910acdbe82f744de7065.1587808742.git.jpoimboe@redhat.com
| | * | x86/unwind: Prevent false warnings for non-current tasksJosh Poimboeuf2020-04-253-18/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's some daring kernel code out there which dumps the stack of another task without first making sure the task is inactive. If the task happens to be running while the unwinder is reading the stack, unusual unwinder warnings can result. There's no race-free way for the unwinder to know whether such a warning is legitimate, so just disable unwinder warnings for all non-current tasks. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/ec424a2aea1d461eb30cab48a28c6433de2ab784.1587808742.git.jpoimboe@redhat.com
| | * | x86/unwind/orc: Convert global variables to staticJosh Poimboeuf2020-04-251-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These variables aren't used outside of unwind_orc.c, make them static. Also annotate some of them with '__ro_after_init', as applicable. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/43ae310bf7822b9862e571f36ae3474cfde8f301.1587808742.git.jpoimboe@redhat.com
| | * | x86/entry/64: Fix unwind hints in rewind_stack_do_exit()Jann Horn2020-04-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The LEAQ instruction in rewind_stack_do_exit() moves the stack pointer directly below the pt_regs at the top of the task stack before calling do_exit(). Tell the unwinder to expect pt_regs. Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/68c33e17ae5963854916a46f522624f8e1d264f2.1587808742.git.jpoimboe@redhat.com
| | * | x86/entry/64: Fix unwind hints in __switch_to_asm()Josh Poimboeuf2020-04-251-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UNWIND_HINT_FUNC has some limitations: specifically, it doesn't reset all the registers to undefined. This causes objtool to get confused about the RBP push in __switch_to_asm(), resulting in bad ORC data. While __switch_to_asm() does do some stack magic, it's otherwise a normal callable-from-C function, so just annotate it as a function, which makes objtool happy and allows it to produces the correct hints automatically. Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/03d0411920d10f7418f2e909210d8e9a3b2ab081.1587808742.git.jpoimboe@redhat.com
| | * | x86/entry/64: Fix unwind hints in kernel exit pathJosh Poimboeuf2020-04-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In swapgs_restore_regs_and_return_to_usermode, after the stack is switched to the trampoline stack, the existing UNWIND_HINT_REGS hint is no longer valid, which can result in the following ORC unwinder warning: WARNING: can't dereference registers at 000000003aeb0cdd for ip swapgs_restore_regs_and_return_to_usermode+0x93/0xa0 For full correctness, we could try to add complicated unwind hints so the unwinder could continue to find the registers, but when when it's this close to kernel exit, unwind hints aren't really needed anymore and it's fine to just use an empty hint which tells the unwinder to stop. For consistency, also move the UNWIND_HINT_EMPTY in entry_SYSCALL_64_after_hwframe to a similar location. Fixes: 3e3b9293d392 ("x86/entry/64: Return to userspace from the trampoline stack") Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Dave Jones <dsj@fb.com> Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reported-by: Joe Mario <jmario@redhat.com> Reported-by: Jann Horn <jannh@google.com> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/60ea8f562987ed2d9ace2977502fe481c0d7c9a0.1587808742.git.jpoimboe@redhat.com
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