September 2024 - Linux-stable-mirror

[PATCH 1/1] io_uring/sqpoll: inherit cpumask of creating process

by Felix Moessbauer

The submit queue polling threads are "kernel" threads that are started from the userland. In case the userland task is part of a cgroup with the cpuset controller enabled, the poller should also stay within that cpuset. This also holds, as the poller belongs to the same cgroup as the task that started it. With the current implementation, a process can "break out" of the defined cpuset by creating sq pollers consuming CPU time on other CPUs, which is especially problematic for realtime applications. Part of this problem was fixed in a5fc1441 by dropping the PF_NO_SETAFFINITY flag, but this only becomes effective after the first modification of the cpuset (i.e. the pollers cpuset is correct after the first update of the enclosing cgroups cpuset). By inheriting the cpuset of the creating tasks, we ensure that the poller is created with a cpumask that is a subset of the cgroups mask. Inheriting the creators cpumask is reasonable, as other userland tasks also inherit the mask. Fixes: 37d1e2e3642e ("io_uring: move SQPOLL thread io-wq forked worker") Cc: stable(a)vger.kernel.org # 6.1+ Signed-off-by: Felix Moessbauer <felix.moessbauer(a)siemens.com> --- io_uring/sqpoll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c index 3b50dc9586d1..4681b2c41a96 100644 --- a/io_uring/sqpoll.c +++ b/io_uring/sqpoll.c @@ -289,7 +289,7 @@ static int io_sq_thread(void *data) if (sqd->sq_cpu != -1) { set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu)); } else { - set_cpus_allowed_ptr(current, cpu_online_mask); + set_cpus_allowed_ptr(current, sqd->thread->cpus_ptr); sqd->sq_cpu = raw_smp_processor_id(); } -- 2.39.2

8 months

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[PATCH] of/irq: handle irq_of_parse_and_map() errors

by Ma Ke

Zero and negative number is not a valid IRQ for in-kernel code and the irq_of_parse_and_map() function returns zero on error. So this check for valid IRQs should only accept values > 0. Cc: stable(a)vger.kernel.org Fixes: f7578496a671 ("of/irq: Use irq_of_parse_and_map()") Signed-off-by: Ma Ke <make24(a)iscas.ac.cn> --- drivers/i2c/busses/i2c-cpm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 4794ec066eb0..41e3c95c0ef7 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -435,7 +435,7 @@ static int cpm_i2c_setup(struct cpm_i2c *cpm) init_waitqueue_head(&cpm->i2c_wait); cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0); - if (!cpm->irq) + if (cpm->irq <= 0) return -EINVAL; /* Install interrupt handler. */ -- 2.25.1

8 months

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[PATCH 1/8] serial: qcom-geni: fix fifo polling timeout

by Johan Hovold

The qcom_geni_serial_poll_bit() can be used to wait for events like command completion and is supposed to wait for the time it takes to clear a full fifo before timing out. As noted by Doug, the current implementation does not account for start, stop and parity bits when determining the timeout. The helper also does not currently account for the shift register and the two-word intermediate transfer register. Instead of determining the fifo timeout on every call, store the timeout when updating it in set_termios() and wait for up to 19/16 the time it takes to clear the 16 word fifo to account for the shift and intermediate registers. Note that serial core has already added a 20 ms margin to the fifo timeout. Also note that the current uart_fifo_timeout() interface does unnecessary calculations on every call and also did not exists in earlier kernels so only store its result once. This also facilitates backports as earlier kernels can derive the timeout from uport->timeout, which has since been removed. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable(a)vger.kernel.org # 4.17 Reported-by: Douglas Anderson <dianders(a)chromium.org> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 69a632fefc41..e1926124339d 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -124,7 +124,7 @@ struct qcom_geni_serial_port { dma_addr_t tx_dma_addr; dma_addr_t rx_dma_addr; bool setup; - unsigned int baud; + unsigned long fifo_timeout_us; unsigned long clk_rate; void *rx_buf; u32 loopback; @@ -270,22 +270,21 @@ static bool qcom_geni_serial_poll_bit(struct uart_port *uport, { u32 reg; struct qcom_geni_serial_port *port; - unsigned int baud; - unsigned int fifo_bits; unsigned long timeout_us = 20000; struct qcom_geni_private_data *private_data = uport->private_data; if (private_data->drv) { port = to_dev_port(uport); - baud = port->baud; - if (!baud) - baud = 115200; - fifo_bits = port->tx_fifo_depth * port->tx_fifo_width; + /* - * Total polling iterations based on FIFO worth of bytes to be - * sent at current baud. Add a little fluff to the wait. + * Wait up to 19/16 the time it would take to clear a full + * FIFO, which accounts for the three words in the shift and + * intermediate registers. + * + * Note that fifo_timeout_us already has a 20 ms margin. */ - timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500; + if (port->fifo_timeout_us) + timeout_us = 19 * port->fifo_timeout_us / 16; } /* @@ -1248,7 +1247,6 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, qcom_geni_serial_stop_rx(uport); /* baud rate */ baud = uart_get_baud_rate(uport, termios, old, 300, 4000000); - port->baud = baud; sampling_rate = UART_OVERSAMPLING; /* Sampling rate is halved for IP versions >= 2.5 */ @@ -1326,8 +1324,10 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, else tx_trans_cfg |= UART_CTS_MASK; - if (baud) + if (baud) { uart_update_timeout(uport, termios->c_cflag, baud); + port->fifo_timeout_us = jiffies_to_usecs(uart_fifo_timeout(uport)); + } if (!uart_console(uport)) writel(port->loopback, -- 2.44.2

8 months

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[PATCH v2 8/8] serial: qcom-geni: fix polled console corruption

by Johan Hovold

The polled UART operations are used by the kernel debugger (KDB, KGDB), which can interrupt the kernel at any point in time. The current Qualcomm GENI implementation does not really work when there is on-going serial output as it inadvertently "hijacks" the current tx command, which can result in both the initial debugger output being corrupted as well as the corruption of any on-going serial output (up to 4k characters) when execution resumes: 0190: abcdefghijklmnopqrstuvwxyz0123456789 0190: abcdefghijklmnopqrstuvwxyz0123456789 0191: abcdefghijklmnop[ 50.825552] sysrq: DEBUG qrstuvwxyz0123456789 0191: abcdefghijklmnopqrstuvwxyz0123456789 Entering kdb (current=0xffff53510b4cd280, pid 640) on processor 2 due to Keyboard Entry [2]kdb> go omlji3h3h2g2g1f1f0e0ezdzdycycxbxbwawav :t72r2rp o9n976k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawavu:t7t8s8s8r2r2q0q0p o9n9n8ml6k6k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawav v u:u:t9t0s4s4rq0p o9n9n8m8m7l7l6k6k5j5j40q0p p o o9n9n8m8m7l7l6k6k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawav :t8t9s4s4r4r4q0q0p Fix this by making sure that the polled output implementation waits for the tx fifo to drain before cancelling any on-going longer transfers. As the polled code cannot take any locks, leave the state variables as they are and instead make sure that the interrupt handler always starts a new tx command when there is data in the write buffer. Since the debugger can interrupt the interrupt handler when it is writing data to the tx fifo, it is currently not possible to fully prevent losing up to 64 bytes of tty output on resume. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable(a)vger.kernel.org # 4.17 Reviewed-by: Douglas Anderson <dianders(a)chromium.org> Tested-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index f23fd0ac3cfd..6f0db310cf69 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -145,6 +145,7 @@ static const struct uart_ops qcom_geni_uart_pops; static struct uart_driver qcom_geni_console_driver; static struct uart_driver qcom_geni_uart_driver; +static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport); static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport); static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport) @@ -384,13 +385,14 @@ static int qcom_geni_serial_get_char(struct uart_port *uport) static void qcom_geni_serial_poll_put_char(struct uart_port *uport, unsigned char c) { - writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + if (qcom_geni_serial_main_active(uport)) { + qcom_geni_serial_poll_tx_done(uport); + __qcom_geni_serial_cancel_tx_cmd(uport); + } + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, 1); - WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, - M_TX_FIFO_WATERMARK_EN, true)); writel(c, uport->membase + SE_GENI_TX_FIFOn); - writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_poll_tx_done(uport); } #endif @@ -677,13 +679,10 @@ static void qcom_geni_serial_stop_tx_fifo(struct uart_port *uport) writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN); } -static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) +static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) { struct qcom_geni_serial_port *port = to_dev_port(uport); - if (!qcom_geni_serial_main_active(uport)) - return; - geni_se_cancel_m_cmd(&port->se); if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_CANCEL_EN, true)) { @@ -693,6 +692,16 @@ static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); } writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); +} + +static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) +{ + struct qcom_geni_serial_port *port = to_dev_port(uport); + + if (!qcom_geni_serial_main_active(uport)) + return; + + __qcom_geni_serial_cancel_tx_cmd(uport); port->tx_remaining = 0; port->tx_queued = 0; @@ -919,7 +928,7 @@ static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport, if (!chunk) goto out_write_wakeup; - if (!port->tx_remaining) { + if (!active) { qcom_geni_serial_setup_tx(uport, pending); port->tx_remaining = pending; port->tx_queued = 0; -- 2.44.2

8 months

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[PATCH v2 6/8] serial: qcom-geni: fix console corruption

by Johan Hovold

The Qualcomm serial console implementation is broken and can lose characters when the serial port is also used for tty output. Specifically, the console code only waits for the current tx command to complete when all data has already been written to the fifo. When there are on-going longer transfers this often means that console output is lost when the console code inadvertently "hijacks" the current tx command instead of starting a new one. This can, for example, be observed during boot when console output that should have been interspersed with init output is truncated: [ 9.462317] qcom-snps-eusb2-hsphy fde000.phy: Registered Qcom-eUSB2 phy [ OK ] Found device KBG50ZNS256G KIOXIA Wi[ 9.471743ndows. [ 9.539915] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller Add a new state variable to track how much data has been written to the fifo and use it to determine when the fifo and shift register are both empty. This is needed since there is currently no other known way to determine when the shift register is empty. This in turn allows the console code to interrupt long transfers without losing data. Note that the oops-in-progress case is similarly broken as it does not cancel any active command and also waits for the wrong status flag when attempting to drain the fifo (TX_FIFO_NOT_EMPTY_EN is only set when cancelling a command leaves data in the fifo). Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Fixes: a1fee899e5be ("tty: serial: qcom_geni_serial: Fix softlock") Fixes: 9e957a155005 ("serial: qcom-geni: Don't cancel/abort if we can't get the port lock") Cc: stable(a)vger.kernel.org # 4.17 Reviewed-by: Douglas Anderson <dianders(a)chromium.org> Tested-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 45 +++++++++++++-------------- 1 file changed, 22 insertions(+), 23 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 7bbd70c30620..f8f6e9466b40 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -131,6 +131,7 @@ struct qcom_geni_serial_port { bool brk; unsigned int tx_remaining; + unsigned int tx_queued; int wakeup_irq; bool rx_tx_swap; bool cts_rts_swap; @@ -144,6 +145,8 @@ static const struct uart_ops qcom_geni_uart_pops; static struct uart_driver qcom_geni_console_driver; static struct uart_driver qcom_geni_uart_driver; +static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport); + static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport) { return container_of(uport, struct qcom_geni_serial_port, uport); @@ -393,6 +396,14 @@ static void qcom_geni_serial_poll_put_char(struct uart_port *uport, #endif #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE +static void qcom_geni_serial_drain_fifo(struct uart_port *uport) +{ + struct qcom_geni_serial_port *port = to_dev_port(uport); + + qcom_geni_serial_poll_bitfield(uport, SE_GENI_M_GP_LENGTH, GP_LENGTH, + port->tx_queued); +} + static void qcom_geni_serial_wr_char(struct uart_port *uport, unsigned char ch) { struct qcom_geni_private_data *private_data = uport->private_data; @@ -468,7 +479,6 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, struct qcom_geni_serial_port *port; bool locked = true; unsigned long flags; - u32 geni_status; WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS); @@ -482,34 +492,20 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, else uart_port_lock_irqsave(uport, &flags); - geni_status = readl(uport->membase + SE_GENI_STATUS); + if (qcom_geni_serial_main_active(uport)) { + /* Wait for completion or drain FIFO */ + if (!locked || port->tx_remaining == 0) + qcom_geni_serial_poll_tx_done(uport); + else + qcom_geni_serial_drain_fifo(uport); - if (!locked) { - /* - * We can only get here if an oops is in progress then we were - * unable to get the lock. This means we can't safely access - * our state variables like tx_remaining. About the best we - * can do is wait for the FIFO to be empty before we start our - * transfer, so we'll do that. - */ - qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, - M_TX_FIFO_NOT_EMPTY_EN, false); - } else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) { - /* - * It seems we can't interrupt existing transfers if all data - * has been sent, in which case we need to look for done first. - */ - qcom_geni_serial_poll_tx_done(uport); + qcom_geni_serial_cancel_tx_cmd(uport); } __qcom_geni_serial_console_write(uport, s, count); - - if (locked) { - if (port->tx_remaining) - qcom_geni_serial_setup_tx(uport, port->tx_remaining); + if (locked) uart_port_unlock_irqrestore(uport, flags); - } } static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop) @@ -690,6 +686,7 @@ static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); port->tx_remaining = 0; + port->tx_queued = 0; } static void qcom_geni_serial_handle_rx_fifo(struct uart_port *uport, bool drop) @@ -916,6 +913,7 @@ static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport, if (!port->tx_remaining) { qcom_geni_serial_setup_tx(uport, pending); port->tx_remaining = pending; + port->tx_queued = 0; irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN); if (!(irq_en & M_TX_FIFO_WATERMARK_EN)) @@ -924,6 +922,7 @@ static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport, } qcom_geni_serial_send_chunk_fifo(uport, chunk); + port->tx_queued += chunk; /* * The tx fifo watermark is level triggered and latched. Though we had -- 2.44.2

8 months

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[PATCH v2 2/8] serial: qcom-geni: fix false console tx restart

by Johan Hovold

Commit 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") addressed an issue with stalled tx after the console code interrupted the last bytes of a tx command by reenabling the watermark interrupt if there is data in write buffer. This can however break software flow control by re-enabling tx after the user has stopped it. Address the original issue by not clearing the CMD_DONE flag after polling for command completion. This allows the interrupt handler to start another transfer when the CMD_DONE interrupt has not been disabled due to flow control. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Fixes: 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") Cc: stable(a)vger.kernel.org # 4.17 Reviewed-by: Douglas Anderson <dianders(a)chromium.org> Tested-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 309c0bddf26a..b88435c0ea50 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -306,18 +306,16 @@ static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size) static void qcom_geni_serial_poll_tx_done(struct uart_port *uport) { int done; - u32 irq_clear = M_CMD_DONE_EN; done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_DONE_EN, true); if (!done) { writel(M_GENI_CMD_ABORT, uport->membase + SE_GENI_M_CMD_CTRL_REG); - irq_clear |= M_CMD_ABORT_EN; qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_ABORT_EN, true); + writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); } - writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR); } static void qcom_geni_serial_abort_rx(struct uart_port *uport) @@ -378,6 +376,7 @@ static void qcom_geni_serial_poll_put_char(struct uart_port *uport, unsigned char c) { writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, 1); WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_TX_FIFO_WATERMARK_EN, true)); @@ -422,6 +421,7 @@ __qcom_geni_serial_console_write(struct uart_port *uport, const char *s, } writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, bytes_to_send); for (i = 0; i < count; ) { size_t chars_to_write = 0; @@ -463,7 +463,6 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, bool locked = true; unsigned long flags; u32 geni_status; - u32 irq_en; WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS); @@ -495,12 +494,6 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, * has been sent, in which case we need to look for done first. */ qcom_geni_serial_poll_tx_done(uport); - - if (!kfifo_is_empty(&uport->state->port.xmit_fifo)) { - irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN); - writel(irq_en | M_TX_FIFO_WATERMARK_EN, - uport->membase + SE_GENI_M_IRQ_EN); - } } __qcom_geni_serial_console_write(uport, s, count); -- 2.44.2

8 months

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[Backport request for 5.4.y] reset: hi6220: Add support for AO reset controller

by Yongqin Liu

Hi, Greg Could you please help to cherry-pick the following commit to the 5.4.y branch? 697fa27dc5fb ("reset: hi6220: Add support for AO reset controller") It's been there since the 5.10 kernel, and this along with the clk patch are needed for Hikey devices to work with the 5.4.y kernels, otherwise it will reboot again and again during the boot. -- Best Regards, Yongqin Liu --------------------------------------------------------------- #mailing list linaro-android(a)lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-android

8 months

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[PATCH v2] powerpc/qspinlock: Fix deadlock in MCS queue

by Nysal Jan K.A.

If an interrupt occurs in queued_spin_lock_slowpath() after we increment qnodesp->count and before node->lock is initialized, another CPU might see stale lock values in get_tail_qnode(). If the stale lock value happens to match the lock on that CPU, then we write to the "next" pointer of the wrong qnode. This causes a deadlock as the former CPU, once it becomes the head of the MCS queue, will spin indefinitely until it's "next" pointer is set by its successor in the queue. Running stress-ng on a 16 core (16EC/16VP) shared LPAR, results in occasional lockups similar to the following: $ stress-ng --all 128 --vm-bytes 80% --aggressive \ --maximize --oomable --verify --syslog \ --metrics --times --timeout 5m watchdog: CPU 15 Hard LOCKUP ...... NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490 LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90 Call Trace: 0xc000002cfffa3bf0 (unreliable) _raw_spin_lock+0x6c/0x90 raw_spin_rq_lock_nested.part.135+0x4c/0xd0 sched_ttwu_pending+0x60/0x1f0 __flush_smp_call_function_queue+0x1dc/0x670 smp_ipi_demux_relaxed+0xa4/0x100 xive_muxed_ipi_action+0x20/0x40 __handle_irq_event_percpu+0x80/0x240 handle_irq_event_percpu+0x2c/0x80 handle_percpu_irq+0x84/0xd0 generic_handle_irq+0x54/0x80 __do_irq+0xac/0x210 __do_IRQ+0x74/0xd0 0x0 do_IRQ+0x8c/0x170 hardware_interrupt_common_virt+0x29c/0x2a0 --- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490 ...... NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490 LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90 --- interrupt: 500 0xc0000029c1a41d00 (unreliable) _raw_spin_lock+0x6c/0x90 futex_wake+0x100/0x260 do_futex+0x21c/0x2a0 sys_futex+0x98/0x270 system_call_exception+0x14c/0x2f0 system_call_vectored_common+0x15c/0x2ec The following code flow illustrates how the deadlock occurs. For the sake of brevity, assume that both locks (A and B) are contended and we call the queued_spin_lock_slowpath() function. CPU0 CPU1 ---- ---- spin_lock_irqsave(A) | spin_unlock_irqrestore(A) | spin_lock(B) | | | ▼ | id = qnodesp->count++; | (Note that nodes[0].lock == A) | | | ▼ | Interrupt | (happens before "nodes[0].lock = B") | | | ▼ | spin_lock_irqsave(A) | | | ▼ | id = qnodesp->count++ | nodes[1].lock = A | | | ▼ | Tail of MCS queue | | spin_lock_irqsave(A) ▼ | Head of MCS queue ▼ | CPU0 is previous tail ▼ | Spin indefinitely ▼ (until "nodes[1].next != NULL") prev = get_tail_qnode(A, CPU0) | ▼ prev == &qnodes[CPU0].nodes[0] (as qnodes[CPU0].nodes[0].lock == A) | ▼ WRITE_ONCE(prev->next, node) | ▼ Spin indefinitely (until nodes[0].locked == 1) Thanks to Saket Kumar Bhaskar for help with recreating the issue Fixes: 84990b169557 ("powerpc/qspinlock: add mcs queueing for contended waiters") Cc: stable(a)vger.kernel.org # v6.2+ Reported-by: Geetika Moolchandani <geetika(a)linux.ibm.com> Reported-by: Vaishnavi Bhat <vaish123(a)in.ibm.com> Reported-by: Jijo Varghese <vargjijo(a)in.ibm.com> Signed-off-by: Nysal Jan K.A. <nysal(a)linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin(a)gmail.com> --- arch/powerpc/lib/qspinlock.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/lib/qspinlock.c b/arch/powerpc/lib/qspinlock.c index 5de4dd549f6e..bcc7e4dff8c3 100644 --- a/arch/powerpc/lib/qspinlock.c +++ b/arch/powerpc/lib/qspinlock.c @@ -697,7 +697,15 @@ static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b } release: - qnodesp->count--; /* release the node */ + /* + * Clear the lock before releasing the node, as another CPU might see stale + * values if an interrupt occurs after we increment qnodesp->count + * but before node->lock is initialized. The barrier ensures that + * there are no further stores to the node after it has been released. + */ + node->lock = NULL; + barrier(); + qnodesp->count--; } void queued_spin_lock_slowpath(struct qspinlock *lock) -- 2.46.0

8 months

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[PATCH 5.10] btrfs: fix use-after-free after failure to create a snapshot

by hsimeliere.opensource＠witekio.com

From: Filipe Manana <fdmanana(a)suse.com> commit 28b21c558a3753171097193b6f6602a94169093a upstream. At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and then attach it to the transaction's list of pending snapshots. After that we call btrfs_commit_transaction(), and if that returns an error we jump to 'fail' label, where we kfree() the pending snapshot structure. This can result in a later use-after-free of the pending snapshot: 1) We allocated the pending snapshot and added it to the transaction's list of pending snapshots; 2) We call btrfs_commit_transaction(), and it fails either at the first call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups(). In both cases, we don't abort the transaction and we release our transaction handle. We jump to the 'fail' label and free the pending snapshot structure. We return with the pending snapshot still in the transaction's list; 3) Another task commits the transaction. This time there's no error at all, and then during the transaction commit it accesses a pointer to the pending snapshot structure that the snapshot creation task has already freed, resulting in a user-after-free. This issue could actually be detected by smatch, which produced the following warning: fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list So fix this by not having the snapshot creation ioctl directly add the pending snapshot to the transaction's list. Instead add the pending snapshot to the transaction handle, and then at btrfs_commit_transaction() we add the snapshot to the list only when we can guarantee that any error returned after that point will result in a transaction abort, in which case the ioctl code can safely free the pending snapshot and no one can access it anymore. CC: stable(a)vger.kernel.org # 5.10+ Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource(a)witekio.com> --- fs/btrfs/ioctl.c | 5 +---- fs/btrfs/transaction.c | 24 ++++++++++++++++++++++++ fs/btrfs/transaction.h | 2 ++ 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index ab8ed187746e..24c4d059cfab 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -853,10 +853,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, goto fail; } - spin_lock(&fs_info->trans_lock); - list_add(&pending_snapshot->list, - &trans->transaction->pending_snapshots); - spin_unlock(&fs_info->trans_lock); + trans->pending_snapshot = pending_snapshot; ret = btrfs_commit_transaction(trans); if (ret) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8cefe11c57db..8878aa7cbdc5 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2075,6 +2075,27 @@ static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle *trans) } } +/* + * Add a pending snapshot associated with the given transaction handle to the + * respective handle. This must be called after the transaction commit started + * and while holding fs_info->trans_lock. + * This serves to guarantee a caller of btrfs_commit_transaction() that it can + * safely free the pending snapshot pointer in case btrfs_commit_transaction() + * returns an error. + */ +static void add_pending_snapshot(struct btrfs_trans_handle *trans) +{ + struct btrfs_transaction *cur_trans = trans->transaction; + + if (!trans->pending_snapshot) + return; + + lockdep_assert_held(&trans->fs_info->trans_lock); + ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_START); + + list_add(&trans->pending_snapshot->list, &cur_trans->pending_snapshots); +} + int btrfs_commit_transaction(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; @@ -2161,6 +2182,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) spin_lock(&fs_info->trans_lock); if (cur_trans->state >= TRANS_STATE_COMMIT_START) { + add_pending_snapshot(trans); + spin_unlock(&fs_info->trans_lock); refcount_inc(&cur_trans->use_count); ret = btrfs_end_transaction(trans); @@ -2243,6 +2266,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * COMMIT_DOING so make sure to wait for num_writers to == 1 again. */ spin_lock(&fs_info->trans_lock); + add_pending_snapshot(trans); cur_trans->state = TRANS_STATE_COMMIT_DOING; spin_unlock(&fs_info->trans_lock); wait_event(cur_trans->writer_wait, diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index f73654d93fa0..eb26eb068fe8 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -122,6 +122,8 @@ struct btrfs_trans_handle { struct btrfs_transaction *transaction; struct btrfs_block_rsv *block_rsv; struct btrfs_block_rsv *orig_rsv; + /* Set by a task that wants to create a snapshot. */ + struct btrfs_pending_snapshot *pending_snapshot; refcount_t use_count; unsigned int type; /* -- 2.43.0

8 months

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Re: [5.15 Backport] cifs: Check the lease context if we actually got a lease

by Greg KH

On Fri, Sep 06, 2024 at 04:07:59PM +0530, Meetakshi Setiya wrote: > Upstream commit 66d45ca1350a3bb8d5f4db8879ccad3ed492337a > > Yes, you are right, it would be good to backport to 6.1 as well. > Please let me know if you need anything from me. I need a working backport for 6.1.y before we can take this one. Oh wait, it's already in 6.1.16, a long time ago. This will be fine, thanks. greg k-h

8 months, 1 week

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Linux-stable-mirror September 2024