Xianting-Tian/…
Commits on Aug 18, 2021
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virtio-console: remove unnecessary kmemdup()
This revert commit c4baad5 ("virtio-console: avoid DMA from stack") hvc framework will never pass stack memory to the put_chars() function, So the calling of kmemdup() is unnecessary, we can remove it. Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Reviewed-by: Shile Zhang <shile.zhang@linux.alibaba.com>
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tty: hvc: pass DMA capable memory to put_chars()
As well known, hvc backend driver(eg, virtio-console) can register its operations to hvc framework. The operations can contain put_chars(), get_chars() and so on. Some hvc backend may do dma in its operations. eg, put_chars() of virtio-console. But in the code of hvc framework, it may pass DMA incapable memory to put_chars() under a specific configuration, which is explained in commit c4baad5(virtio-console: avoid DMA from stack): 1, c[] is on stack, hvc_console_print(): char c[N_OUTBUF] __ALIGNED__; cons_ops[index]->put_chars(vtermnos[index], c, i); 2, ch is on stack, static void hvc_poll_put_char(,,char ch) { struct tty_struct *tty = driver->ttys[0]; struct hvc_struct *hp = tty->driver_data; int n; do { n = hp->ops->put_chars(hp->vtermno, &ch, 1); } while (n <= 0); } Commit c4baad5 is just the fix to avoid DMA from stack memory, which is passed to virtio-console by hvc framework in above code. But I think the fix is aggressive, it directly uses kmemdup() to alloc new buffer from kmalloc area and do memcpy no matter the memory is in kmalloc area or not. But most importantly, it should better be fixed in the hvc framework, by changing it to never pass stack memory to the put_chars() function in the first place. Otherwise, we still face the same issue if a new hvc backend using dma added in the future. In this patch, we make 'char out_buf[N_OUTBUF]' and 'chat out_ch' part of 'struct hvc_struct', so both two buf are no longer the stack memory. we can use it in above two cases separately. Introduce another array(cons_outbufs[]) for buffer pointers next to the cons_ops[] and vtermnos[] arrays. With the array, we can easily find the buffer, instead of traversing hp list. With the patch, we can remove the fix c4baad5. Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Reviewed-by: Shile Zhang <shile.zhang@linux.alibaba.com>
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tty: hvc: use correct dma alignment size
Use L1_CACHE_BYTES as the dma alignment size, use 'sizeof(long)' is wrong. Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Reviewed-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Commits on Aug 16, 2021
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tty: replace in_irq() with in_hardirq()
Replace the obsolete and ambiguos macro in_irq() with new macro in_hardirq(). Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Changbin Du <changbin.du@gmail.com> Link: https://lore.kernel.org/r/20210814005033.2381-1-changbin.du@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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serial: sh-sci: fix break handling for sysrq
This fixes two issues that cause the sysrq sequence to be inadvertently aborted on SCIF serial consoles: - a NUL character remains in the RX queue after a break has been detected, which is then passed on to uart_handle_sysrq_char() - the break interrupt is handled twice on controllers with multiplexed ERI and BRI interrupts Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Link: https://lore.kernel.org/r/20210816162201.28801-1-uli+renesas@fpond.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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serial: stm32: use devm_platform_get_and_ioremap_resource()
Use devm_platform_get_and_ioremap_resource() to simplify code. Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com> Link: https://lore.kernel.org/r/20210814131418.13608-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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serial: stm32: use the defined variable to simplify code
Use the defined variable 'dev' to make the code cleaner. Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com> Link: https://lore.kernel.org/r/20210814124951.30084-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Revert "arm pl011 serial: support multi-irq request"
This reverts commit b081946 which results in amba_device-specific code being called from sbsa_uart_startup() and sbsa_uart_shutdown(). Signed-off-by: Qian Cai <quic_qiancai@quicinc.com> Link: https://lore.kernel.org/r/20210813163135.205-1-quic_qiancai@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commits on Aug 13, 2021
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tty: serial: samsung: Add Exynos850 SoC data
Add serial driver data for Exynos850 SoC. This driver data is basically reusing EXYNOS_COMMON_SERIAL_DRV_DATA, which is common for all Exynos chips, but also enables USI init, which was added in previous commit: "tty: serial: samsung: Init USI to keep clocks running". Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> Link: https://lore.kernel.org/r/20210811114827.27322-7-semen.protsenko@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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tty: serial: samsung: Fix driver data macros style
Make checkpatch happy by fixing this error: ERROR: Macros with complex values should be enclosed in parentheses Although this change is made to keep macros consistent with consequent patches (adding driver data for new SoC), it's intentionally added as a separate patch to ease possible porting efforts in future. Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> Link: https://lore.kernel.org/r/20210811114827.27322-6-semen.protsenko@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -
tty: serial: samsung: Init USI to keep clocks running
UART block is a part of USI (Universal Serial Interface) IP-core in Samsung SoCs since Exynos9810 (e.g. in Exynos850). USI allows one to enable one of three types of serial interface: UART, SPI or I2C. That's possible because USI shares almost all internal circuits within each protocol. USI also provides some additional registers so it's possible to configure it. One USI register called USI_OPTION has reset value of 0x0. Because of this the clock gating behavior is controlled by hardware (HWACG = Hardware Auto Clock Gating), which simply means the serial won't work after reset as is. In order to make it work, USI_OPTION[2:1] bits must be set to 0b01, so that HWACG is controlled manually (by software). Bits meaning: - CLKREQ_ON = 1: clock is continuously provided to IP - CLKSTOP_ON = 0: drive IP_CLKREQ to High (needs to be set along with CLKREQ_ON = 1) USI is not present on older chips, like s3c2410, s3c2412, s3c2440, s3c6400, s5pv210, exynos5433, exynos4210. So the new boolean field '.has_usi' was added to struct s3c24xx_uart_info. USI registers will be only actually accessed when '.has_usi' field is set to "1". This feature is needed for further serial enablement on Exynos850, but some other new Exynos chips (like Exynos9810) may benefit from this feature as well. Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> Link: https://lore.kernel.org/r/20210811114827.27322-5-semen.protsenko@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -
platform/surface: aggregator: Use serdev_acpi_get_uart_resource() helper
serdev provides a generic helper to get UART Serial Bus resources. Use it instead of an open coded variant. Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20210806111736.66591-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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serdev: Split and export serdev_acpi_get_uart_resource()
The same as for I²C Serial Bus resource split and export serdev_acpi_get_uart_resource(). We have already a few users one of which is converted here. Rationale of this is to consolidate parsing UART Serial Bus resource in one place as it's done, e.g., for I²C Serial Bus. Reviewed-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20210806111736.66591-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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serial: stm32: fix the conditional expression writing
In the function stm32_usart_init_port, intent of the code maybe when irq returns a value of zero, the return should be '-ENODEV'. But the conditional expression '? :' maybe clerical error, it should be '?:' to make '-ENODEV' work. But in fact, as the example in platform.c is * int irq = platform_get_irq(pdev, 0); * if (irq < 0) * return irq; So the return value of zero is unnecessary to check, at last remove the unnecessary '?: -ENODEV'. Co-developed-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com> Link: https://lore.kernel.org/r/20210811105136.25392-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commits on Aug 9, 2021
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We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commits on Aug 8, 2021
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Merge tag 'timers-urgent-2021-08-08' of git://git.kernel.org/pub/scm/…
…linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single timer fix: - Prevent a memory ordering issue in the timer expiry code which makes it possible to observe falsely that the callback has been executed already while that's not the case, which violates the guarantee of del_timer_sync()" * tag 'timers-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Move clearing of base::timer_running under base:: Lock -
Merge tag 'sched-urgent-2021-08-08' of git://git.kernel.org/pub/scm/l…
…inux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "A single scheduler fix: - Prevent a double enqueue caused by rt_effective_prio() being invoked twice in __sched_setscheduler()" * tag 'sched-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt: Fix double enqueue caused by rt_effective_prio -
Merge tag 'perf-urgent-2021-08-08' of git://git.kernel.org/pub/scm/li…
…nux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A set of perf fixes: - Correct the permission checks for perf event which send SIGTRAP to a different process and clean up that code to be more readable. - Prevent an out of bound MSR access in the x86 perf code which happened due to an incomplete limiting to the actually available hardware counters. - Prevent access to the AMD64_EVENTSEL_HOSTONLY bit when running inside a guest. - Handle small core counter re-enabling correctly by issuing an ACK right before reenabling it to prevent a stale PEBS record being kept around" * tag 'perf-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Apply mid ACK for small core perf/x86/amd: Don't touch the AMD64_EVENTSEL_HOSTONLY bit inside the guest perf/x86: Fix out of bound MSR access perf: Refactor permissions check into perf_check_permission() perf: Fix required permissions if sigtrap is requested -
Merge tag 'char-misc-5.14-rc5' of git://git.kernel.org/pub/scm/linux/…
…kernel/git/gregkh/char-misc Pull char/misc driver fixes from Greg KH: "Here are some small char/misc driver fixes for 5.14-rc5. They resolve a few regressions that people reported: - acrn driver fix - fpga driver fix - interconnect tiny driver fixes All have been in linux-next for a while with no reported issues" * tag 'char-misc-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: interconnect: Fix undersized devress_alloc allocation interconnect: qcom: icc-rpmh: Add BCMs to commit list in pre_aggregate interconnect: qcom: icc-rpmh: Ensure floor BW is enforced for all nodes fpga: dfl: fme: Fix cpu hotplug issue in performance reporting virt: acrn: Do hcall_destroy_vm() before resource release interconnect: Always call pre_aggregate before aggregate interconnect: Zero initial BW after sync-state
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Merge tag 'driver-core-5.14-rc5' of git://git.kernel.org/pub/scm/linu…
…x/kernel/git/gregkh/driver-core Pull driver core fixes from Greg KH: "Here are three tiny driver core and firmware loader fixes for 5.14-rc5. They are: - driver core fix for when probing fails - firmware loader fixes for reported problems. All have been in linux-next for a while with no reported issues" * tag 'driver-core-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: firmware_loader: fix use-after-free in firmware_fallback_sysfs firmware_loader: use -ETIMEDOUT instead of -EAGAIN in fw_load_sysfs_fallback drivers core: Fix oops when driver probe fails
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Merge tag 'staging-5.14-rc5' of git://git.kernel.org/pub/scm/linux/ke…
…rnel/git/gregkh/staging Pull staging driver fixes from Greg KH: "Here are a few small staging driver fixes for 5.14-rc5 to resolve some reported problems. They include: - mt7621 driver fix - rtl8723bs driver fixes - rtl8712 driver fixes. Nothing major, just small problems resolved. All have been in linux-next for a while with no reported issues" * tag 'staging-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: staging: mt7621-pci: avoid to re-disable clock for those pcies not in use staging: rtl8712: error handling refactoring staging: rtl8712: get rid of flush_scheduled_work staging: rtl8723bs: select CONFIG_CRYPTO_LIB_ARC4 staging: rtl8723bs: Fix a resource leak in sd_int_dpc
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Merge tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel…
…/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are some small tty/serial driver fixes for 5.14-rc5 to resolve a number of reported problems. They include: - mips serial driver fixes - 8250 driver fixes for reported problems - fsl_lpuart driver fixes - other tiny driver fixes All have been in linux-next for a while with no reported problems" * tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: 8250_pci: Avoid irq sharing for MSI(-X) interrupts. serial: 8250_mtk: fix uart corruption issue when rx power off tty: serial: fsl_lpuart: fix the wrong return value in lpuart32_get_mctrl serial: 8250_pci: Enumerate Elkhart Lake UARTs via dedicated driver serial: 8250: fix handle_irq locking serial: tegra: Only print FIFO error message when an error occurs MIPS: Malta: Do not byte-swap accesses to the CBUS UART serial: 8250: Mask out floating 16/32-bit bus bits serial: max310x: Unprepare and disable clock in error path
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Merge tag 'usb-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel…
…/git/gregkh/usb Pull USB driver fixes from Greg KH: "Here are some small USB driver fixes for 5.14-rc5. They resolve a number of small reported issues, including: - cdnsp driver fixes - usb serial driver fixes and device id updates - usb gadget hid fixes - usb host driver fixes - usb dwc3 driver fixes - other usb gadget driver fixes All of these have been in linux-next for a while with no reported issues" * tag 'usb-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (21 commits) usb: typec: tcpm: Keep other events when receiving FRS and Sourcing_vbus events usb: dwc3: gadget: Avoid runtime resume if disabling pullup usb: dwc3: gadget: Use list_replace_init() before traversing lists USB: serial: ftdi_sio: add device ID for Auto-M3 OP-COM v2 USB: serial: pl2303: fix GT type detection USB: serial: option: add Telit FD980 composition 0x1056 USB: serial: pl2303: fix HX type detection USB: serial: ch341: fix character loss at high transfer rates usb: cdnsp: Fix the IMAN_IE_SET and IMAN_IE_CLEAR macro usb: cdnsp: Fixed issue with ZLP usb: cdnsp: Fix incorrect supported maximum speed usb: cdns3: Fixed incorrect gadget state usb: gadget: f_hid: idle uses the highest byte for duration Revert "thunderbolt: Hide authorized attribute if router does not support PCIe tunnels" usb: otg-fsm: Fix hrtimer list corruption usb: host: ohci-at91: suspend/resume ports after/before OHCI accesses usb: musb: Fix suspend and resume issues for PHYs on I2C and SPI usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers usb: gadget: f_hid: fixed NULL pointer dereference usb: gadget: remove leaked entry from udc driver list ...
Commits on Aug 7, 2021
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Merge tag 'io_uring-5.14-2021-08-07' of git://git.kernel.dk/linux-block
Pull io_uring from Jens Axboe: "A few io-wq related fixes: - Fix potential nr_worker race and missing max_workers check from one path (Hao) - Fix race between worker exiting and new work queue (me)" * tag 'io_uring-5.14-2021-08-07' of git://git.kernel.dk/linux-block: io-wq: fix lack of acct->nr_workers < acct->max_workers judgement io-wq: fix no lock protection of acct->nr_worker io-wq: fix race between worker exiting and activating free worker -
Merge tag 'block-5.14-2021-08-07' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe: "A few minor fixes: - Fix ldm kernel-doc warning (Bart) - Fix adding offset twice for DMA address in n64cart (Christoph) - Fix use-after-free in dasd path handling (Stefan) - Order kyber insert trace correctly (Vincent) - raid1 errored write handling fix (Wei) - Fix blk-iolatency queue get failure handling (Yu)" * tag 'block-5.14-2021-08-07' of git://git.kernel.dk/linux-block: kyber: make trace_block_rq call consistent with documentation block/partitions/ldm.c: Fix a kernel-doc warning blk-iolatency: error out if blk_get_queue() failed in iolatency_set_limit() n64cart: fix the dma address in n64cart_do_bvec s390/dasd: fix use after free in dasd path handling md/raid10: properly indicate failure when ending a failed write request
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Merge tag 'riscv-for-linus-5.14-rc5' of git://git.kernel.org/pub/scm/…
…linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - avoid dereferencing a null task pointer while walking the stack - fix the memory size in the HiFive Unleashed device tree - disable stack protectors when randstruct is enabled, which results in non-deterministic offsets during module builds - a pair of fixes to avoid relying on a constant physical memory base for the non-XIP builds * tag 'riscv-for-linus-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: Revert "riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED" riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical address conversion riscv: Disable STACKPROTECTOR_PER_TASK if GCC_PLUGIN_RANDSTRUCT is enabled riscv: dts: fix memory size for the SiFive HiFive Unmatched riscv: stacktrace: Fix NULL pointer dereference
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Merge tag 'kbuild-fixes-v5.14-2' of git://git.kernel.org/pub/scm/linu…
…x/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Correct the Extended Regular Expressions in tools - Adjust scripts/checkversion.pl for the current Kbuild - Unset sub_make_done for 'make install' to make DKMS work again * tag 'kbuild-fixes-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: cancel sub_make_done for the install target to fix DKMS scripts: checkversion: modernize linux/version.h search strings mips: Fix non-POSIX regexp x86/tools/relocs: Fix non-POSIX regexp
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Revert "riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED"
This reverts commit 9b79878. The removal of this config exposes CONFIG_PHYS_RAM_BASE for all kernel types: this value being implementation-specific, this breaks the genericity of the RISC-V kernel so revert it. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Tested-by: Emil Renner Berthing <kernel@esmil.dk> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical address con…
…version The usage of CONFIG_PHYS_RAM_BASE for all kernel types was a mistake: this value is implementation-specific and this breaks the genericity of the RISC-V kernel. Fix this by introducing a new variable phys_ram_base that holds this value at runtime and use it in the kernel physical address conversion macro. Since this value is used only for XIP kernels, evaluate it only if CONFIG_XIP_KERNEL is set which in addition optimizes this macro for standard kernels at compile-time. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Tested-by: Emil Renner Berthing <kernel@esmil.dk> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Fixes: 44c9225 ("RISC-V: enable XIP") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Commits on Aug 6, 2021
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kyber: make trace_block_rq call consistent with documentation
The kyber ioscheduler calls trace_block_rq_insert() *after* the request is added to the queue but the documentation for trace_block_rq_insert() says that the call should be made *before* the request is added to the queue. Move the tracepoint for the kyber ioscheduler so that it is consistent with the documentation. Signed-off-by: Vincent Fu <vincent.fu@samsung.com> Link: https://lore.kernel.org/r/20210804194913.10497-1-vincent.fu@samsung.com Reviewed by: Adam Manzanares <a.manzanares@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/lin…
…ux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "A regression fix, bug fix, and a comment cleanup for ext4" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix potential htree corruption when growing large_dir directories ext4: remove conflicting comment from __ext4_forget ext4: fix potential uninitialized access to retval in kmmpd
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Merge tag 'trace-v5.14-rc4-2' of git://git.kernel.org/pub/scm/linux/k…
…ernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Fix tracepoint race between static_call and callback data As callbacks to a tracepoint are paired with the data that is passed in when the callback is registered to the tracepoint, it must have that data passed to the callback when the tracepoint is triggered, else bad things will happen. To keep the two together, they are both assigned to a tracepoint structure and added to an array. The tracepoint call site will dereference the structure (via RCU) and call the callback in that structure along with the data in that structure. This keeps the callback and data tightly coupled. Because of the overhead that retpolines have on tracepoint callbacks, if there's only one callback attached to a tracepoint (a common case), then it is called via a static call (code modified to do a direct call instead of an indirect call). But to implement this, the data had to be decoupled from the callback, as now the callback is implemented via a direct call from the static call and not an indirect call from the dereferenced structure. Note, the static call only calls a callback used when there's a single callback attached to the tracepoint. If more than one callback is attached to the same tracepoint, then the static call will call an iterator function that goes back to dereferencing the structure keeping the callback and its data tightly coupled again. Issues can arise when going from 0 callbacks to one, as the static call is assigned to the callback, and it must take care that the data passed to it is loaded before the static call calls the callback. Going from 1 to 2 callbacks is not an issue, as long as the static call is updated to the iterator before the tracepoint structure array is updated via RCU. Going from 2 to more or back down to 2 is not an issue as the iterator can handle all theses cases. But going from 2 to 1, care must be taken as the static call is now calling a callback and the data that is loaded must be the data for that callback. Care was taken to ensure the callback and data would be in-sync, but after a bug was reported, it became clear that not enough was done to make sure that was the case. These changes address this. The first change is to compare the old and new data instead of the old and new callback, as it's the data that can corrupt the callback, even if the callback is the same (something getting freed). The next change is to convert these transitions into states, to make it easier to know when a synchronization is needed, and to perform those synchronizations. The problem with this patch is that it slows down disabling all events from under a second, to making it take over 10 seconds to do the same work. But that is addressed in the final patch. The final patch uses the RCU state functions to keep track of the RCU state between the transitions, and only needs to perform the synchronization if an RCU synchronization hasn't been done already. This brings the performance of disabling all events back to its original value. That's because no synchronization is required between disabling tracepoints but is required when enabling a tracepoint after its been disabled. If an RCU synchronization happens after the tracepoint is disabled, and before it is re-enabled, there's no need to do the synchronization again. Both the second and third patch have subtle complexities that they are separated into two patches. But because the second patch causes such a regression in performance, the third patch adds a "Fixes" tag to the second patch, such that the two must be backported together and not just the second patch" * tag 'trace-v5.14-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracepoint: Use rcu get state and cond sync for static call updates tracepoint: Fix static call function vs data state mismatch tracepoint: static call: Compare data on transition from 2->1 callees
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Merge tag 'pm-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/…
…git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "Fix a recent regression in the timer events oriented (TEO) cpuidle governor causing it to misbehave when idle state 0 is disabled and rename two local variables for improved clarity on top of that" * tag 'pm-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: teo: Rename two local variables in teo_select() cpuidle: teo: Fix alternative idle state lookup
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Merge tag 'acpi-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kerne…
…l/git/rafael/linux-pm Pull ACPI fix from Rafael Wysocki: "Revert a recent ACPICA commit causing boot issues to appear on some systems" * tag 'acpi-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "ACPICA: Fix memory leak caused by _CID repair function"