From a7b8829d242b1a58107e9c02b09e93aec446d55c Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Wed, 5 Jul 2017 20:30:01 +0200 Subject: iio: accel: st_accel: add SPI-3wire support Add SPI Serial Interface Mode (SIM) register information in st_sensor_settings look up table to support devices (like LSM303AGR accel sensor) that allow just SPI-3wire communication mode. SIM mode has to be configured before any other operation since it is not enabled by default and the driver is not able to read without that configuration Whilst a fairly substantial patch, the actual logic is simple and it is better to have the generic fix than a band aid. Fixes: ddc05fa28606 (iio: st-accel: add support for lsm303agr accel) Signed-off-by: Lorenzo Bianconi Cc: Signed-off-by: Jonathan Cameron --- include/linux/iio/common/st_sensors.h | 7 +++++++ include/linux/platform_data/st_sensors_pdata.h | 2 ++ 2 files changed, 9 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h index 497f2b3a5a62..97f1b465d04f 100644 --- a/include/linux/iio/common/st_sensors.h +++ b/include/linux/iio/common/st_sensors.h @@ -105,6 +105,11 @@ struct st_sensor_fullscale { struct st_sensor_fullscale_avl fs_avl[ST_SENSORS_FULLSCALE_AVL_MAX]; }; +struct st_sensor_sim { + u8 addr; + u8 value; +}; + /** * struct st_sensor_bdu - ST sensor device block data update * @addr: address of the register. @@ -197,6 +202,7 @@ struct st_sensor_transfer_function { * @bdu: Block data update register. * @das: Data Alignment Selection register. * @drdy_irq: Data ready register of the sensor. + * @sim: SPI serial interface mode register of the sensor. * @multi_read_bit: Use or not particular bit for [I2C/SPI] multi-read. * @bootime: samples to discard when sensor passing from power-down to power-up. */ @@ -213,6 +219,7 @@ struct st_sensor_settings { struct st_sensor_bdu bdu; struct st_sensor_das das; struct st_sensor_data_ready_irq drdy_irq; + struct st_sensor_sim sim; bool multi_read_bit; unsigned int bootime; }; diff --git a/include/linux/platform_data/st_sensors_pdata.h b/include/linux/platform_data/st_sensors_pdata.h index 79b0e4cdb814..f8274b0c6888 100644 --- a/include/linux/platform_data/st_sensors_pdata.h +++ b/include/linux/platform_data/st_sensors_pdata.h @@ -17,10 +17,12 @@ * Available only for accelerometer and pressure sensors. * Accelerometer DRDY on LSM330 available only on pin 1 (see datasheet). * @open_drain: set the interrupt line to be open drain if possible. + * @spi_3wire: enable spi-3wire mode. */ struct st_sensors_platform_data { u8 drdy_int_pin; bool open_drain; + bool spi_3wire; }; #endif /* ST_SENSORS_PDATA_H */ -- cgit v1.2.3 From 37ef38f3f83891a2f413fb872bae7d0f9bb95b27 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Thu, 27 Jul 2017 16:15:52 -0500 Subject: tty: pl011: fix initialization order of QDF2400 E44 The work-around for Qualcomm Technologies QDF2400 Erratum 44 hinges on a global variable defined in the pl011 driver. The ACPI SPCR parsing code determines whether the work-around is needed, and if so, it changes the console name from "pl011" to "qdf2400_e44". The expectation is that the pl011 driver will implement the work-around when it sees the console name. The global variable qdf2400_e44_present is set when that happens. The problem is that work-around needs to be enabled when the pl011 driver probes, not when the console name is queried. However, sbsa_probe() is called before pl011_console_match(). The work-around appeared to work previously because the default console on QDF2400 platforms was always ttyAMA1. The first time sbsa_probe() is called (for ttyAMA0), qdf2400_e44_present is still false. Then pl011_console_match() is called, and it sets qdf2400_e44_present to true. All subsequent calls to sbsa_probe() enable the work-around. The solution is to move the global variable into spcr.c and let the pl011 driver query it during probe time. This works because all QDF2400 platforms require SPCR, so parse_spcr() will always be called. pl011_console_match still checks for the "qdf2400_e44" console name, but it doesn't do anything else special. Fixes: 5a0722b898f8 ("tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44") Tested-by: Jeffrey Hugo Signed-off-by: Timur Tabi Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/spcr.c | 36 ++++++++++++++++++++++++++++++++++-- drivers/tty/serial/amba-pl011.c | 37 +++++++++++++++++++------------------ include/linux/acpi.h | 1 + 3 files changed, 54 insertions(+), 20 deletions(-) (limited to 'include/linux') diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index 4ac3e06b41d8..98aa8c808a33 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -16,6 +16,16 @@ #include #include +/* + * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as + * occasionally getting stuck as 1. To avoid the potential for a hang, check + * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART + * implementations, so only do so if an affected platform is detected in + * parse_spcr(). + */ +bool qdf2400_e44_present; +EXPORT_SYMBOL(qdf2400_e44_present); + /* * Some Qualcomm Datacenter Technologies SoCs have a defective UART BUSY bit. * Detect them by examining the OEM fields in the SPCR header, similiar to PCI @@ -147,8 +157,30 @@ int __init parse_spcr(bool earlycon) goto done; } - if (qdf2400_erratum_44_present(&table->header)) - uart = "qdf2400_e44"; + /* + * If the E44 erratum is required, then we need to tell the pl011 + * driver to implement the work-around. + * + * The global variable is used by the probe function when it + * creates the UARTs, whether or not they're used as a console. + * + * If the user specifies "traditional" earlycon, the qdf2400_e44 + * console name matches the EARLYCON_DECLARE() statement, and + * SPCR is not used. Parameter "earlycon" is false. + * + * If the user specifies "SPCR" earlycon, then we need to update + * the console name so that it also says "qdf2400_e44". Parameter + * "earlycon" is true. + * + * For consistency, if we change the console name, then we do it + * for everyone, not just earlycon. + */ + if (qdf2400_erratum_44_present(&table->header)) { + qdf2400_e44_present = true; + if (earlycon) + uart = "qdf2400_e44"; + } + if (xgene_8250_erratum_present(table)) iotype = "mmio32"; diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 8a857bb34fbb..1888d168a41c 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -142,15 +142,7 @@ static struct vendor_data vendor_sbsa = { .fixed_options = true, }; -/* - * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as - * occasionally getting stuck as 1. To avoid the potential for a hang, check - * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART - * implementations, so only do so if an affected platform is detected in - * parse_spcr(). - */ -static bool qdf2400_e44_present = false; - +#ifdef CONFIG_ACPI_SPCR_TABLE static struct vendor_data vendor_qdt_qdf2400_e44 = { .reg_offset = pl011_std_offsets, .fr_busy = UART011_FR_TXFE, @@ -165,6 +157,7 @@ static struct vendor_data vendor_qdt_qdf2400_e44 = { .always_enabled = true, .fixed_options = true, }; +#endif static u16 pl011_st_offsets[REG_ARRAY_SIZE] = { [REG_DR] = UART01x_DR, @@ -2375,12 +2368,14 @@ static int __init pl011_console_match(struct console *co, char *name, int idx, resource_size_t addr; int i; - if (strcmp(name, "qdf2400_e44") == 0) { - pr_info_once("UART: Working around QDF2400 SoC erratum 44"); - qdf2400_e44_present = true; - } else if (strcmp(name, "pl011") != 0) { + /* + * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum + * have a distinct console name, so make sure we check for that. + * The actual implementation of the erratum occurs in the probe + * function. + */ + if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0)) return -ENODEV; - } if (uart_parse_earlycon(options, &iotype, &addr, &options)) return -ENODEV; @@ -2734,11 +2729,17 @@ static int sbsa_uart_probe(struct platform_device *pdev) } uap->port.irq = ret; - uap->reg_offset = vendor_sbsa.reg_offset; - uap->vendor = qdf2400_e44_present ? - &vendor_qdt_qdf2400_e44 : &vendor_sbsa; +#ifdef CONFIG_ACPI_SPCR_TABLE + if (qdf2400_e44_present) { + dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n"); + uap->vendor = &vendor_qdt_qdf2400_e44; + } else +#endif + uap->vendor = &vendor_sbsa; + + uap->reg_offset = uap->vendor->reg_offset; uap->fifosize = 32; - uap->port.iotype = vendor_sbsa.access_32b ? UPIO_MEM32 : UPIO_MEM; + uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM; uap->port.ops = &sbsa_uart_pops; uap->fixed_baud = baudrate; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index c749eef1daa1..27b4b6615263 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1209,6 +1209,7 @@ static inline bool acpi_has_watchdog(void) { return false; } #endif #ifdef CONFIG_ACPI_SPCR_TABLE +extern bool qdf2400_e44_present; int parse_spcr(bool earlycon); #else static inline int parse_spcr(bool earlycon) { return 0; } -- cgit v1.2.3 From 0fb228d30b8d72bfee51f57e638d412324d44a11 Mon Sep 17 00:00:00 2001 From: James Smart Date: Tue, 1 Aug 2017 15:12:39 -0700 Subject: nvmet_fc: add defer_req callback for deferment of cmd buffer return At queue creation, the transport allocates a local job struct (struct nvmet_fc_fcp_iod) for each possible element of the queue. When a new CMD is received from the wire, a jobs struct is allocated from the queue and then used for the duration of the command. The job struct contains buffer space for the wire command iu. Thus, upon allocation of the job struct, the cmd iu buffer is copied to the job struct and the LLDD may immediately free/reuse the CMD IU buffer passed in the call. However, in some circumstances, due to the packetized nature of FC and the api of the FC LLDD which may issue a hw command to send the wire response, but the LLDD may not get the hw completion for the command and upcall the nvmet_fc layer before a new command may be asynchronously received on the wire. In other words, its possible for the initiator to get the response from the wire, thus believe a command slot free, and send a new command iu. The new command iu may be received by the LLDD and passed to the transport before the LLDD had serviced the hw completion and made the teardown calls for the original job struct. As such, there is no available job struct available for the new io. E.g. it appears like the host sent more queue elements than the queue size. It didn't based on it's understanding. Rather than treat this as a hard connection failure queue the new request until the job struct does free up. As the buffer isn't copied as there's no job struct, a special return value must be returned to the LLDD to signify to hold off on recycling the cmd iu buffer. And later, when a job struct is allocated and the buffer copied, a new LLDD callback is introduced to notify the LLDD and allow it to recycle it's command iu buffer. Signed-off-by: James Smart Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig --- drivers/nvme/target/fc.c | 212 +++++++++++++++++++++++++++++++++++------ include/linux/nvme-fc-driver.h | 7 ++ 2 files changed, 191 insertions(+), 28 deletions(-) (limited to 'include/linux') diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c index 31ca55dfcb1d..1b7f2520a20d 100644 --- a/drivers/nvme/target/fc.c +++ b/drivers/nvme/target/fc.c @@ -114,6 +114,11 @@ struct nvmet_fc_tgtport { struct kref ref; }; +struct nvmet_fc_defer_fcp_req { + struct list_head req_list; + struct nvmefc_tgt_fcp_req *fcp_req; +}; + struct nvmet_fc_tgt_queue { bool ninetypercent; u16 qid; @@ -132,6 +137,8 @@ struct nvmet_fc_tgt_queue { struct nvmet_fc_tgt_assoc *assoc; struct nvmet_fc_fcp_iod *fod; /* array of fcp_iods */ struct list_head fod_list; + struct list_head pending_cmd_list; + struct list_head avail_defer_list; struct workqueue_struct *work_q; struct kref ref; } __aligned(sizeof(unsigned long long)); @@ -223,6 +230,8 @@ static void nvmet_fc_tgt_q_put(struct nvmet_fc_tgt_queue *queue); static int nvmet_fc_tgt_q_get(struct nvmet_fc_tgt_queue *queue); static void nvmet_fc_tgtport_put(struct nvmet_fc_tgtport *tgtport); static int nvmet_fc_tgtport_get(struct nvmet_fc_tgtport *tgtport); +static void nvmet_fc_handle_fcp_rqst(struct nvmet_fc_tgtport *tgtport, + struct nvmet_fc_fcp_iod *fod); /* *********************** FC-NVME DMA Handling **************************** */ @@ -463,9 +472,9 @@ static struct nvmet_fc_fcp_iod * nvmet_fc_alloc_fcp_iod(struct nvmet_fc_tgt_queue *queue) { static struct nvmet_fc_fcp_iod *fod; - unsigned long flags; - spin_lock_irqsave(&queue->qlock, flags); + lockdep_assert_held(&queue->qlock); + fod = list_first_entry_or_null(&queue->fod_list, struct nvmet_fc_fcp_iod, fcp_list); if (fod) { @@ -477,17 +486,37 @@ nvmet_fc_alloc_fcp_iod(struct nvmet_fc_tgt_queue *queue) * will "inherit" that reference. */ } - spin_unlock_irqrestore(&queue->qlock, flags); return fod; } +static void +nvmet_fc_queue_fcp_req(struct nvmet_fc_tgtport *tgtport, + struct nvmet_fc_tgt_queue *queue, + struct nvmefc_tgt_fcp_req *fcpreq) +{ + struct nvmet_fc_fcp_iod *fod = fcpreq->nvmet_fc_private; + + /* + * put all admin cmds on hw queue id 0. All io commands go to + * the respective hw queue based on a modulo basis + */ + fcpreq->hwqid = queue->qid ? + ((queue->qid - 1) % tgtport->ops->max_hw_queues) : 0; + + if (tgtport->ops->target_features & NVMET_FCTGTFEAT_CMD_IN_ISR) + queue_work_on(queue->cpu, queue->work_q, &fod->work); + else + nvmet_fc_handle_fcp_rqst(tgtport, fod); +} + static void nvmet_fc_free_fcp_iod(struct nvmet_fc_tgt_queue *queue, struct nvmet_fc_fcp_iod *fod) { struct nvmefc_tgt_fcp_req *fcpreq = fod->fcpreq; struct nvmet_fc_tgtport *tgtport = fod->tgtport; + struct nvmet_fc_defer_fcp_req *deferfcp; unsigned long flags; fc_dma_sync_single_for_cpu(tgtport->dev, fod->rspdma, @@ -495,21 +524,56 @@ nvmet_fc_free_fcp_iod(struct nvmet_fc_tgt_queue *queue, fcpreq->nvmet_fc_private = NULL; - spin_lock_irqsave(&queue->qlock, flags); - list_add_tail(&fod->fcp_list, &fod->queue->fod_list); fod->active = false; fod->abort = false; fod->aborted = false; fod->writedataactive = false; fod->fcpreq = NULL; + + tgtport->ops->fcp_req_release(&tgtport->fc_target_port, fcpreq); + + spin_lock_irqsave(&queue->qlock, flags); + deferfcp = list_first_entry_or_null(&queue->pending_cmd_list, + struct nvmet_fc_defer_fcp_req, req_list); + if (!deferfcp) { + list_add_tail(&fod->fcp_list, &fod->queue->fod_list); + spin_unlock_irqrestore(&queue->qlock, flags); + + /* Release reference taken at queue lookup and fod allocation */ + nvmet_fc_tgt_q_put(queue); + return; + } + + /* Re-use the fod for the next pending cmd that was deferred */ + list_del(&deferfcp->req_list); + + fcpreq = deferfcp->fcp_req; + + /* deferfcp can be reused for another IO at a later date */ + list_add_tail(&deferfcp->req_list, &queue->avail_defer_list); + spin_unlock_irqrestore(&queue->qlock, flags); + /* Save NVME CMD IO in fod */ + memcpy(&fod->cmdiubuf, fcpreq->rspaddr, fcpreq->rsplen); + + /* Setup new fcpreq to be processed */ + fcpreq->rspaddr = NULL; + fcpreq->rsplen = 0; + fcpreq->nvmet_fc_private = fod; + fod->fcpreq = fcpreq; + fod->active = true; + + /* inform LLDD IO is now being processed */ + tgtport->ops->defer_rcv(&tgtport->fc_target_port, fcpreq); + + /* Submit deferred IO for processing */ + nvmet_fc_queue_fcp_req(tgtport, queue, fcpreq); + /* - * release the reference taken at queue lookup and fod allocation + * Leave the queue lookup get reference taken when + * fod was originally allocated. */ - nvmet_fc_tgt_q_put(queue); - - tgtport->ops->fcp_req_release(&tgtport->fc_target_port, fcpreq); } static int @@ -569,6 +633,8 @@ nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc, queue->port = assoc->tgtport->port; queue->cpu = nvmet_fc_queue_to_cpu(assoc->tgtport, qid); INIT_LIST_HEAD(&queue->fod_list); + INIT_LIST_HEAD(&queue->avail_defer_list); + INIT_LIST_HEAD(&queue->pending_cmd_list); atomic_set(&queue->connected, 0); atomic_set(&queue->sqtail, 0); atomic_set(&queue->rsn, 1); @@ -638,6 +704,7 @@ nvmet_fc_delete_target_queue(struct nvmet_fc_tgt_queue *queue) { struct nvmet_fc_tgtport *tgtport = queue->assoc->tgtport; struct nvmet_fc_fcp_iod *fod = queue->fod; + struct nvmet_fc_defer_fcp_req *deferfcp; unsigned long flags; int i, writedataactive; bool disconnect; @@ -666,6 +733,35 @@ nvmet_fc_delete_target_queue(struct nvmet_fc_tgt_queue *queue) } } } + + /* Cleanup defer'ed IOs in queue */ + list_for_each_entry(deferfcp, &queue->avail_defer_list, req_list) { + list_del(&deferfcp->req_list); + kfree(deferfcp); + } + + for (;;) { + deferfcp = list_first_entry_or_null(&queue->pending_cmd_list, + struct nvmet_fc_defer_fcp_req, req_list); + if (!deferfcp) + break; + + list_del(&deferfcp->req_list); + spin_unlock_irqrestore(&queue->qlock, flags); + + tgtport->ops->defer_rcv(&tgtport->fc_target_port, + deferfcp->fcp_req); + + tgtport->ops->fcp_abort(&tgtport->fc_target_port, + deferfcp->fcp_req); + + tgtport->ops->fcp_req_release(&tgtport->fc_target_port, + deferfcp->fcp_req); + + kfree(deferfcp); + + spin_lock_irqsave(&queue->qlock, flags); + } spin_unlock_irqrestore(&queue->qlock, flags); flush_workqueue(queue->work_q); @@ -2172,11 +2268,38 @@ nvmet_fc_handle_fcp_rqst_work(struct work_struct *work) * Pass a FC-NVME FCP CMD IU received from the FC link to the nvmet-fc * layer for processing. * - * The nvmet-fc layer will copy cmd payload to an internal structure for - * processing. As such, upon completion of the routine, the LLDD may - * immediately free/reuse the CMD IU buffer passed in the call. + * The nvmet_fc layer allocates a local job structure (struct + * nvmet_fc_fcp_iod) from the queue for the io and copies the + * CMD IU buffer to the job structure. As such, on a successful + * completion (returns 0), the LLDD may immediately free/reuse + * the CMD IU buffer passed in the call. + * + * However, in some circumstances, due to the packetized nature of FC + * and the api of the FC LLDD which may issue a hw command to send the + * response, but the LLDD may not get the hw completion for that command + * and upcall the nvmet_fc layer before a new command may be + * asynchronously received - its possible for a command to be received + * before the LLDD and nvmet_fc have recycled the job structure. It gives + * the appearance of more commands received than fits in the sq. + * To alleviate this scenario, a temporary queue is maintained in the + * transport for pending LLDD requests waiting for a queue job structure. + * In these "overrun" cases, a temporary queue element is allocated + * the LLDD request and CMD iu buffer information remembered, and the + * routine returns a -EOVERFLOW status. Subsequently, when a queue job + * structure is freed, it is immediately reallocated for anything on the + * pending request list. The LLDDs defer_rcv() callback is called, + * informing the LLDD that it may reuse the CMD IU buffer, and the io + * is then started normally with the transport. * - * If this routine returns error, the lldd should abort the exchange. + * The LLDD, when receiving an -EOVERFLOW completion status, is to treat + * the completion as successful but must not reuse the CMD IU buffer + * until the LLDD's defer_rcv() callback has been called for the + * corresponding struct nvmefc_tgt_fcp_req pointer. + * + * If there is any other condition in which an error occurs, the + * transport will return a non-zero status indicating the error. + * In all cases other than -EOVERFLOW, the transport has not accepted the + * request and the LLDD should abort the exchange. * * @target_port: pointer to the (registered) target port the FCP CMD IU * was received on. @@ -2194,6 +2317,8 @@ nvmet_fc_rcv_fcp_req(struct nvmet_fc_target_port *target_port, struct nvme_fc_cmd_iu *cmdiu = cmdiubuf; struct nvmet_fc_tgt_queue *queue; struct nvmet_fc_fcp_iod *fod; + struct nvmet_fc_defer_fcp_req *deferfcp; + unsigned long flags; /* validate iu, so the connection id can be used to find the queue */ if ((cmdiubuf_len != sizeof(*cmdiu)) || @@ -2214,29 +2339,60 @@ nvmet_fc_rcv_fcp_req(struct nvmet_fc_target_port *target_port, * when the fod is freed. */ + spin_lock_irqsave(&queue->qlock, flags); + fod = nvmet_fc_alloc_fcp_iod(queue); - if (!fod) { + if (fod) { + spin_unlock_irqrestore(&queue->qlock, flags); + + fcpreq->nvmet_fc_private = fod; + fod->fcpreq = fcpreq; + + memcpy(&fod->cmdiubuf, cmdiubuf, cmdiubuf_len); + + nvmet_fc_queue_fcp_req(tgtport, queue, fcpreq); + + return 0; + } + + if (!tgtport->ops->defer_rcv) { + spin_unlock_irqrestore(&queue->qlock, flags); /* release the queue lookup reference */ nvmet_fc_tgt_q_put(queue); return -ENOENT; } - fcpreq->nvmet_fc_private = fod; - fod->fcpreq = fcpreq; - /* - * put all admin cmds on hw queue id 0. All io commands go to - * the respective hw queue based on a modulo basis - */ - fcpreq->hwqid = queue->qid ? - ((queue->qid - 1) % tgtport->ops->max_hw_queues) : 0; - memcpy(&fod->cmdiubuf, cmdiubuf, cmdiubuf_len); + deferfcp = list_first_entry_or_null(&queue->avail_defer_list, + struct nvmet_fc_defer_fcp_req, req_list); + if (deferfcp) { + /* Just re-use one that was previously allocated */ + list_del(&deferfcp->req_list); + } else { + spin_unlock_irqrestore(&queue->qlock, flags); - if (tgtport->ops->target_features & NVMET_FCTGTFEAT_CMD_IN_ISR) - queue_work_on(queue->cpu, queue->work_q, &fod->work); - else - nvmet_fc_handle_fcp_rqst(tgtport, fod); + /* Now we need to dynamically allocate one */ + deferfcp = kmalloc(sizeof(*deferfcp), GFP_KERNEL); + if (!deferfcp) { + /* release the queue lookup reference */ + nvmet_fc_tgt_q_put(queue); + return -ENOMEM; + } + spin_lock_irqsave(&queue->qlock, flags); + } - return 0; + /* For now, use rspaddr / rsplen to save payload information */ + fcpreq->rspaddr = cmdiubuf; + fcpreq->rsplen = cmdiubuf_len; + deferfcp->fcp_req = fcpreq; + + /* defer processing till a fod becomes available */ + list_add_tail(&deferfcp->req_list, &queue->pending_cmd_list); + + /* NOTE: the queue lookup reference is still valid */ + + spin_unlock_irqrestore(&queue->qlock, flags); + + return -EOVERFLOW; } EXPORT_SYMBOL_GPL(nvmet_fc_rcv_fcp_req); diff --git a/include/linux/nvme-fc-driver.h b/include/linux/nvme-fc-driver.h index 6c8c5d8041b7..2591878c1d48 100644 --- a/include/linux/nvme-fc-driver.h +++ b/include/linux/nvme-fc-driver.h @@ -346,6 +346,11 @@ struct nvme_fc_remote_port { * indicating an FC transport Aborted status. * Entrypoint is Mandatory. * + * @defer_rcv: Called by the transport to signal the LLLD that it has + * begun processing of a previously received NVME CMD IU. The LLDD + * is now free to re-use the rcv buffer associated with the + * nvmefc_tgt_fcp_req. + * * @max_hw_queues: indicates the maximum number of hw queues the LLDD * supports for cpu affinitization. * Value is Mandatory. Must be at least 1. @@ -846,6 +851,8 @@ struct nvmet_fc_target_template { struct nvmefc_tgt_fcp_req *fcpreq); void (*fcp_req_release)(struct nvmet_fc_target_port *tgtport, struct nvmefc_tgt_fcp_req *fcpreq); + void (*defer_rcv)(struct nvmet_fc_target_port *tgtport, + struct nvmefc_tgt_fcp_req *fcpreq); u32 max_hw_queues; u16 max_sgl_segments; -- cgit v1.2.3 From bfe334924ccd9f4a53f30240c03cf2f43f5b2df1 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 2 Aug 2017 19:39:30 +0200 Subject: perf/x86: Fix RDPMC vs. mm_struct tracking Vince reported the following rdpmc() testcase failure: > Failing test case: > > fd=perf_event_open(); > addr=mmap(fd); > exec() // without closing or unmapping the event > fd=perf_event_open(); > addr=mmap(fd); > rdpmc() // GPFs due to rdpmc being disabled The problem is of course that exec() plays tricks with what is current->mm, only destroying the old mappings after having installed the new mm. Fix this confusion by passing along vma->vm_mm instead of relying on current->mm. Reported-by: Vince Weaver Tested-by: Vince Weaver Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 1e0fb9ec679c ("perf: Add pmu callbacks to track event mapping and unmapping") Link: http://lkml.kernel.org/r/20170802173930.cstykcqefmqt7jau@hirez.programming.kicks-ass.net [ Minor cleanups. ] Signed-off-by: Ingo Molnar --- arch/x86/events/core.c | 16 +++++++--------- include/linux/perf_event.h | 4 ++-- kernel/events/core.c | 6 +++--- 3 files changed, 12 insertions(+), 14 deletions(-) (limited to 'include/linux') diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 8e3db8f642a7..af12e294caed 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2114,7 +2114,7 @@ static void refresh_pce(void *ignored) load_mm_cr4(this_cpu_read(cpu_tlbstate.loaded_mm)); } -static void x86_pmu_event_mapped(struct perf_event *event) +static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm) { if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED)) return; @@ -2129,22 +2129,20 @@ static void x86_pmu_event_mapped(struct perf_event *event) * For now, this can't happen because all callers hold mmap_sem * for write. If this changes, we'll need a different solution. */ - lockdep_assert_held_exclusive(¤t->mm->mmap_sem); + lockdep_assert_held_exclusive(&mm->mmap_sem); - if (atomic_inc_return(¤t->mm->context.perf_rdpmc_allowed) == 1) - on_each_cpu_mask(mm_cpumask(current->mm), refresh_pce, NULL, 1); + if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1) + on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1); } -static void x86_pmu_event_unmapped(struct perf_event *event) +static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm) { - if (!current->mm) - return; if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED)) return; - if (atomic_dec_and_test(¤t->mm->context.perf_rdpmc_allowed)) - on_each_cpu_mask(mm_cpumask(current->mm), refresh_pce, NULL, 1); + if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed)) + on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1); } static int x86_pmu_event_idx(struct perf_event *event) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index a3b873fc59e4..b14095bcf4bb 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -310,8 +310,8 @@ struct pmu { * Notification that the event was mapped or unmapped. Called * in the context of the mapping task. */ - void (*event_mapped) (struct perf_event *event); /*optional*/ - void (*event_unmapped) (struct perf_event *event); /*optional*/ + void (*event_mapped) (struct perf_event *event, struct mm_struct *mm); /* optional */ + void (*event_unmapped) (struct perf_event *event, struct mm_struct *mm); /* optional */ /* * Flags for ->add()/->del()/ ->start()/->stop(). There are diff --git a/kernel/events/core.c b/kernel/events/core.c index 426c2ffba16d..a654b8a3586f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5090,7 +5090,7 @@ static void perf_mmap_open(struct vm_area_struct *vma) atomic_inc(&event->rb->aux_mmap_count); if (event->pmu->event_mapped) - event->pmu->event_mapped(event); + event->pmu->event_mapped(event, vma->vm_mm); } static void perf_pmu_output_stop(struct perf_event *event); @@ -5113,7 +5113,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) unsigned long size = perf_data_size(rb); if (event->pmu->event_unmapped) - event->pmu->event_unmapped(event); + event->pmu->event_unmapped(event, vma->vm_mm); /* * rb->aux_mmap_count will always drop before rb->mmap_count and @@ -5411,7 +5411,7 @@ aux_unlock: vma->vm_ops = &perf_mmap_vmops; if (event->pmu->event_mapped) - event->pmu->event_mapped(event); + event->pmu->event_mapped(event, vma->vm_mm); return ret; } -- cgit v1.2.3 From a99b646afa8a02571ea298bedca6592d818229cd Mon Sep 17 00:00:00 2001 From: dingtianhong Date: Tue, 15 Aug 2017 11:23:23 +0800 Subject: PCI: Disable PCIe Relaxed Ordering if unsupported When bit4 is set in the PCIe Device Control register, it indicates whether the device is permitted to use relaxed ordering. On some platforms using relaxed ordering can have performance issues or due to erratum can cause data-corruption. In such cases devices must avoid using relaxed ordering. The patch adds a new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING to indicate that Relaxed Ordering (RO) attribute should not be used for Transaction Layer Packets (TLP) targeted towards these affected root complexes. This patch checks if there is any node in the hierarchy that indicates that using relaxed ordering is not safe. In such cases the patch turns off the relaxed ordering by clearing the capability for this device. Signed-off-by: Casey Leedom Signed-off-by: Ding Tianhong Acked-by: Ashok Raj Acked-by: Alexander Duyck Acked-by: Casey Leedom Signed-off-by: David S. Miller --- drivers/pci/probe.c | 43 +++++++++++++++++++++++++++++++++++++++++++ drivers/pci/quirks.c | 11 +++++++++++ include/linux/pci.h | 3 +++ 3 files changed, 57 insertions(+) (limited to 'include/linux') diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c31310db0404..e6a917b4acd3 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1762,6 +1762,48 @@ static void pci_configure_extended_tags(struct pci_dev *dev) PCI_EXP_DEVCTL_EXT_TAG); } +/** + * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable + * @dev: PCI device to query + * + * Returns true if the device has enabled relaxed ordering attribute. + */ +bool pcie_relaxed_ordering_enabled(struct pci_dev *dev) +{ + u16 v; + + pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v); + + return !!(v & PCI_EXP_DEVCTL_RELAX_EN); +} +EXPORT_SYMBOL(pcie_relaxed_ordering_enabled); + +static void pci_configure_relaxed_ordering(struct pci_dev *dev) +{ + struct pci_dev *root; + + /* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */ + if (dev->is_virtfn) + return; + + if (!pcie_relaxed_ordering_enabled(dev)) + return; + + /* + * For now, we only deal with Relaxed Ordering issues with Root + * Ports. Peer-to-Peer DMA is another can of worms. + */ + root = pci_find_pcie_root_port(dev); + if (!root) + return; + + if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) { + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, + PCI_EXP_DEVCTL_RELAX_EN); + dev_info(&dev->dev, "Disable Relaxed Ordering because the Root Port didn't support it\n"); + } +} + static void pci_configure_device(struct pci_dev *dev) { struct hotplug_params hpp; @@ -1769,6 +1811,7 @@ static void pci_configure_device(struct pci_dev *dev) pci_configure_mps(dev); pci_configure_extended_tags(dev); + pci_configure_relaxed_ordering(dev); memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 6967c6b4cf6b..61b59bfa7bfc 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4015,6 +4015,17 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(0x1797, 0x6868, PCI_CLASS_NOT_DEFINED, 8, DECLARE_PCI_FIXUP_CLASS_EARLY(0x1797, 0x6869, PCI_CLASS_NOT_DEFINED, 8, quirk_tw686x_class); +/* + * Some devices have problems with Transaction Layer Packets with the Relaxed + * Ordering Attribute set. Such devices should mark themselves and other + * Device Drivers should check before sending TLPs with RO set. + */ +static void quirk_relaxedordering_disable(struct pci_dev *dev) +{ + dev->dev_flags |= PCI_DEV_FLAGS_NO_RELAXED_ORDERING; + dev_info(&dev->dev, "Disable Relaxed Ordering Attributes to avoid PCIe Completion erratum\n"); +} + /* * Per PCIe r3.0, sec 2.2.9, "Completion headers must supply the same * values for the Attribute as were supplied in the header of the diff --git a/include/linux/pci.h b/include/linux/pci.h index 4869e66dd659..29606fb89464 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -188,6 +188,8 @@ enum pci_dev_flags { * the direct_complete optimization. */ PCI_DEV_FLAGS_NEEDS_RESUME = (__force pci_dev_flags_t) (1 << 11), + /* Don't use Relaxed Ordering for TLPs directed at this device */ + PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 12), }; enum pci_irq_reroute_variant { @@ -1125,6 +1127,7 @@ bool pci_check_pme_status(struct pci_dev *dev); void pci_pme_wakeup_bus(struct pci_bus *bus); void pci_d3cold_enable(struct pci_dev *dev); void pci_d3cold_disable(struct pci_dev *dev); +bool pcie_relaxed_ordering_enabled(struct pci_dev *dev); /* PCI Virtual Channel */ int pci_save_vc_state(struct pci_dev *dev); -- cgit v1.2.3 From b3dc8f772fab5b2d284b780830fd56494491e493 Mon Sep 17 00:00:00 2001 From: Tonghao Zhang Date: Tue, 15 Aug 2017 04:28:54 -0700 Subject: net: Fix a typo in comment about sock flags. Signed-off-by: Tonghao Zhang Signed-off-by: David S. Miller --- include/linux/net.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/net.h b/include/linux/net.h index dda2cc939a53..ebeb48c92005 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -37,7 +37,7 @@ struct net; /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected. - * Eventually all flags will be in sk->sk_wq_flags. + * Eventually all flags will be in sk->sk_wq->flags. */ #define SOCKWQ_ASYNC_NOSPACE 0 #define SOCKWQ_ASYNC_WAITDATA 1 -- cgit v1.2.3 From 81fbfe8adaf38d4f5a98c19bebfd41c5d6acaee8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 16 Aug 2017 10:36:47 -0700 Subject: ptr_ring: use kmalloc_array() As found by syzkaller, malicious users can set whatever tx_queue_len on a tun device and eventually crash the kernel. Lets remove the ALIGN(XXX, SMP_CACHE_BYTES) thing since a small ring buffer is not fast anyway. Fixes: 2e0ab8ca83c1 ("ptr_ring: array based FIFO for pointers") Signed-off-by: Eric Dumazet Reported-by: Dmitry Vyukov Cc: Michael S. Tsirkin Cc: Jason Wang Signed-off-by: David S. Miller --- include/linux/ptr_ring.h | 9 +++++---- include/linux/skb_array.h | 3 ++- 2 files changed, 7 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index d8c97ec8a8e6..37b4bb2545b3 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -436,9 +436,9 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r, __PTR_RING_PEEK_CALL_v; \ }) -static inline void **__ptr_ring_init_queue_alloc(int size, gfp_t gfp) +static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp) { - return kzalloc(ALIGN(size * sizeof(void *), SMP_CACHE_BYTES), gfp); + return kcalloc(size, sizeof(void *), gfp); } static inline void __ptr_ring_set_size(struct ptr_ring *r, int size) @@ -582,7 +582,8 @@ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp, * In particular if you consume ring in interrupt or BH context, you must * disable interrupts/BH when doing so. */ -static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings, +static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, + unsigned int nrings, int size, gfp_t gfp, void (*destroy)(void *)) { @@ -590,7 +591,7 @@ static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings, void ***queues; int i; - queues = kmalloc(nrings * sizeof *queues, gfp); + queues = kmalloc_array(nrings, sizeof(*queues), gfp); if (!queues) goto noqueues; diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h index 35226cd4efb0..8621ffdeecbf 100644 --- a/include/linux/skb_array.h +++ b/include/linux/skb_array.h @@ -193,7 +193,8 @@ static inline int skb_array_resize(struct skb_array *a, int size, gfp_t gfp) } static inline int skb_array_resize_multiple(struct skb_array **rings, - int nrings, int size, gfp_t gfp) + int nrings, unsigned int size, + gfp_t gfp) { BUILD_BUG_ON(offsetof(struct skb_array, ring)); return ptr_ring_resize_multiple((struct ptr_ring **)rings, -- cgit v1.2.3 From c8c03f1858331e85d397bacccd34ef409aae993c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 16 Aug 2017 17:08:07 -0700 Subject: pty: fix the cached path of the pty slave file descriptor in the master Christian Brauner reported that if you use the TIOCGPTPEER ioctl() to get a slave pty file descriptor, the resulting file descriptor doesn't look right in /proc//fd/. In particular, he wanted to use readlink() on /proc/self/fd/ to get the pathname of the slave pty (basically implementing "ptsname{_r}()"). The reason for that was that we had generated the wrong 'struct path' when we create the pty in ptmx_open(). In particular, the dentry was correct, but the vfsmount pointed to the mount of the ptmx node. That _can_ be correct - in case you use "/dev/pts/ptmx" to open the master - but usually is not. The normal case is to use /dev/ptmx, which then looks up the pts/ directory, and then the vfsmount of the ptmx node is obviously the /dev directory, not the /dev/pts/ directory. We actually did have the right vfsmount available, but in the wrong place (it gets looked up in 'devpts_acquire()' when we get a reference to the pts filesystem), and so ptmx_open() used the wrong mnt pointer. The end result of this confusion was that the pty worked fine, but when if you did TIOCGPTPEER to get the slave side of the pty, end end result would also work, but have that dodgy 'struct path'. And then when doing "d_path()" on to get the pathname, the vfsmount would not match the root of the pts directory, and d_path() would return an empty pathname thinking that the entry had escaped a bind mount into another mount. This fixes the problem by making devpts_acquire() return the vfsmount for the pts filesystem, allowing ptmx_open() to trivially just use the right mount for the pts dentry, and create the proper 'struct path'. Reported-by: Christian Brauner Cc: Al Viro Acked-by: Eric Biederman Signed-off-by: Linus Torvalds --- drivers/tty/pty.c | 7 +++++-- fs/devpts/inode.c | 4 +++- include/linux/devpts_fs.h | 2 +- 3 files changed, 9 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 284749fb0f6b..1fc80ea87c13 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -793,6 +793,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) struct tty_struct *tty; struct path *pts_path; struct dentry *dentry; + struct vfsmount *mnt; int retval; int index; @@ -805,7 +806,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) return retval; - fsi = devpts_acquire(filp); + fsi = devpts_acquire(filp, &mnt); if (IS_ERR(fsi)) { retval = PTR_ERR(fsi); goto out_free_file; @@ -849,7 +850,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) pts_path = kmalloc(sizeof(struct path), GFP_KERNEL); if (!pts_path) goto err_release; - pts_path->mnt = filp->f_path.mnt; + pts_path->mnt = mnt; pts_path->dentry = dentry; path_get(pts_path); tty->link->driver_data = pts_path; @@ -866,6 +867,7 @@ err_path_put: path_put(pts_path); kfree(pts_path); err_release: + mntput(mnt); tty_unlock(tty); // This will also put-ref the fsi tty_release(inode, filp); @@ -874,6 +876,7 @@ out: devpts_kill_index(fsi, index); out_put_fsi: devpts_release(fsi); + mntput(mnt); out_free_file: tty_free_file(filp); return retval; diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 108df2e3602c..44dfbca9306f 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -133,7 +133,7 @@ static inline struct pts_fs_info *DEVPTS_SB(struct super_block *sb) return sb->s_fs_info; } -struct pts_fs_info *devpts_acquire(struct file *filp) +struct pts_fs_info *devpts_acquire(struct file *filp, struct vfsmount **ptsmnt) { struct pts_fs_info *result; struct path path; @@ -142,6 +142,7 @@ struct pts_fs_info *devpts_acquire(struct file *filp) path = filp->f_path; path_get(&path); + *ptsmnt = NULL; /* Has the devpts filesystem already been found? */ sb = path.mnt->mnt_sb; @@ -165,6 +166,7 @@ struct pts_fs_info *devpts_acquire(struct file *filp) * pty code needs to hold extra references in case of last /dev/tty close */ atomic_inc(&sb->s_active); + *ptsmnt = mntget(path.mnt); result = DEVPTS_SB(sb); out: diff --git a/include/linux/devpts_fs.h b/include/linux/devpts_fs.h index 277ab9af9ac2..7883e901f65c 100644 --- a/include/linux/devpts_fs.h +++ b/include/linux/devpts_fs.h @@ -19,7 +19,7 @@ struct pts_fs_info; -struct pts_fs_info *devpts_acquire(struct file *); +struct pts_fs_info *devpts_acquire(struct file *, struct vfsmount **ptsmnt); void devpts_release(struct pts_fs_info *); int devpts_new_index(struct pts_fs_info *); -- cgit v1.2.3 From 7edaeb6841dfb27e362288ab8466ebdc4972e867 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 15 Aug 2017 09:50:13 +0200 Subject: kernel/watchdog: Prevent false positives with turbo modes The hardlockup detector on x86 uses a performance counter based on unhalted CPU cycles and a periodic hrtimer. The hrtimer period is about 2/5 of the performance counter period, so the hrtimer should fire 2-3 times before the performance counter NMI fires. The NMI code checks whether the hrtimer fired since the last invocation. If not, it assumess a hard lockup. The calculation of those periods is based on the nominal CPU frequency. Turbo modes increase the CPU clock frequency and therefore shorten the period of the perf/NMI watchdog. With extreme Turbo-modes (3x nominal frequency) the perf/NMI period is shorter than the hrtimer period which leads to false positives. A simple fix would be to shorten the hrtimer period, but that comes with the side effect of more frequent hrtimer and softlockup thread wakeups, which is not desired. Implement a low pass filter, which checks the perf/NMI period against kernel time. If the perf/NMI fires before 4/5 of the watchdog period has elapsed then the event is ignored and postponed to the next perf/NMI. That solves the problem and avoids the overhead of shorter hrtimer periods and more frequent softlockup thread wakeups. Fixes: 58687acba592 ("lockup_detector: Combine nmi_watchdog and softlockup detector") Reported-and-tested-by: Kan Liang Signed-off-by: Thomas Gleixner Cc: dzickus@redhat.com Cc: prarit@redhat.com Cc: ak@linux.intel.com Cc: babu.moger@oracle.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: acme@redhat.com Cc: stable@vger.kernel.org Cc: atomlin@redhat.com Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1708150931310.1886@nanos --- arch/x86/Kconfig | 1 + include/linux/nmi.h | 8 +++++++ kernel/watchdog.c | 1 + kernel/watchdog_hld.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 7 ++++++ 5 files changed, 76 insertions(+) (limited to 'include/linux') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 781521b7cf9e..9101bfc85539 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -100,6 +100,7 @@ config X86 select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL + select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 select HAVE_ACPI_APEI if ACPI select HAVE_ACPI_APEI_NMI if ACPI select HAVE_ALIGNED_STRUCT_PAGE if SLUB diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 8aa01fd859fb..a36abe2da13e 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -168,6 +168,14 @@ extern int sysctl_hardlockup_all_cpu_backtrace; #define sysctl_softlockup_all_cpu_backtrace 0 #define sysctl_hardlockup_all_cpu_backtrace 0 #endif + +#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ + defined(CONFIG_HARDLOCKUP_DETECTOR) +void watchdog_update_hrtimer_threshold(u64 period); +#else +static inline void watchdog_update_hrtimer_threshold(u64 period) { } +#endif + extern bool is_hardlockup(void); struct ctl_table; extern int proc_watchdog(struct ctl_table *, int , diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 06d3389bca0d..f5d52024f6b7 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -240,6 +240,7 @@ static void set_sample_period(void) * hardlockup detector generates a warning */ sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5); + watchdog_update_hrtimer_threshold(sample_period); } /* Commands for resetting the watchdog */ diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 295a0d84934c..3a09ea1b1d3d 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -37,6 +37,62 @@ void arch_touch_nmi_watchdog(void) } EXPORT_SYMBOL(arch_touch_nmi_watchdog); +#ifdef CONFIG_HARDLOCKUP_CHECK_TIMESTAMP +static DEFINE_PER_CPU(ktime_t, last_timestamp); +static DEFINE_PER_CPU(unsigned int, nmi_rearmed); +static ktime_t watchdog_hrtimer_sample_threshold __read_mostly; + +void watchdog_update_hrtimer_threshold(u64 period) +{ + /* + * The hrtimer runs with a period of (watchdog_threshold * 2) / 5 + * + * So it runs effectively with 2.5 times the rate of the NMI + * watchdog. That means the hrtimer should fire 2-3 times before + * the NMI watchdog expires. The NMI watchdog on x86 is based on + * unhalted CPU cycles, so if Turbo-Mode is enabled the CPU cycles + * might run way faster than expected and the NMI fires in a + * smaller period than the one deduced from the nominal CPU + * frequency. Depending on the Turbo-Mode factor this might be fast + * enough to get the NMI period smaller than the hrtimer watchdog + * period and trigger false positives. + * + * The sample threshold is used to check in the NMI handler whether + * the minimum time between two NMI samples has elapsed. That + * prevents false positives. + * + * Set this to 4/5 of the actual watchdog threshold period so the + * hrtimer is guaranteed to fire at least once within the real + * watchdog threshold. + */ + watchdog_hrtimer_sample_threshold = period * 2; +} + +static bool watchdog_check_timestamp(void) +{ + ktime_t delta, now = ktime_get_mono_fast_ns(); + + delta = now - __this_cpu_read(last_timestamp); + if (delta < watchdog_hrtimer_sample_threshold) { + /* + * If ktime is jiffies based, a stalled timer would prevent + * jiffies from being incremented and the filter would look + * at a stale timestamp and never trigger. + */ + if (__this_cpu_inc_return(nmi_rearmed) < 10) + return false; + } + __this_cpu_write(nmi_rearmed, 0); + __this_cpu_write(last_timestamp, now); + return true; +} +#else +static inline bool watchdog_check_timestamp(void) +{ + return true; +} +#endif + static struct perf_event_attr wd_hw_attr = { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES, @@ -61,6 +117,9 @@ static void watchdog_overflow_callback(struct perf_event *event, return; } + if (!watchdog_check_timestamp()) + return; + /* check for a hardlockup * This is done by making sure our timer interrupt * is incrementing. The timer interrupt should have diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 98fe715522e8..c617b9d1d6cb 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -797,6 +797,13 @@ config HARDLOCKUP_DETECTOR_PERF bool select SOFTLOCKUP_DETECTOR +# +# Enables a timestamp based low pass filter to compensate for perf based +# hard lockup detection which runs too fast due to turbo modes. +# +config HARDLOCKUP_CHECK_TIMESTAMP + bool + # # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard # lockup detector rather than the perf based detector. -- cgit v1.2.3 From 739f79fc9db1b38f96b5a5109b247a650fbebf6d Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Fri, 18 Aug 2017 15:15:48 -0700 Subject: mm: memcontrol: fix NULL pointer crash in test_clear_page_writeback() Jaegeuk and Brad report a NULL pointer crash when writeback ending tries to update the memcg stats: BUG: unable to handle kernel NULL pointer dereference at 00000000000003b0 IP: test_clear_page_writeback+0x12e/0x2c0 [...] RIP: 0010:test_clear_page_writeback+0x12e/0x2c0 Call Trace: end_page_writeback+0x47/0x70 f2fs_write_end_io+0x76/0x180 [f2fs] bio_endio+0x9f/0x120 blk_update_request+0xa8/0x2f0 scsi_end_request+0x39/0x1d0 scsi_io_completion+0x211/0x690 scsi_finish_command+0xd9/0x120 scsi_softirq_done+0x127/0x150 __blk_mq_complete_request_remote+0x13/0x20 flush_smp_call_function_queue+0x56/0x110 generic_smp_call_function_single_interrupt+0x13/0x30 smp_call_function_single_interrupt+0x27/0x40 call_function_single_interrupt+0x89/0x90 RIP: 0010:native_safe_halt+0x6/0x10 (gdb) l *(test_clear_page_writeback+0x12e) 0xffffffff811bae3e is in test_clear_page_writeback (./include/linux/memcontrol.h:619). 614 mod_node_page_state(page_pgdat(page), idx, val); 615 if (mem_cgroup_disabled() || !page->mem_cgroup) 616 return; 617 mod_memcg_state(page->mem_cgroup, idx, val); 618 pn = page->mem_cgroup->nodeinfo[page_to_nid(page)]; 619 this_cpu_add(pn->lruvec_stat->count[idx], val); 620 } 621 622 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, 623 gfp_t gfp_mask, The issue is that writeback doesn't hold a page reference and the page might get freed after PG_writeback is cleared (and the mapping is unlocked) in test_clear_page_writeback(). The stat functions looking up the page's node or zone are safe, as those attributes are static across allocation and free cycles. But page->mem_cgroup is not, and it will get cleared if we race with truncation or migration. It appears this race window has been around for a while, but less likely to trigger when the memcg stats were updated first thing after PG_writeback is cleared. Recent changes reshuffled this code to update the global node stats before the memcg ones, though, stretching the race window out to an extent where people can reproduce the problem. Update test_clear_page_writeback() to look up and pin page->mem_cgroup before clearing PG_writeback, then not use that pointer afterward. It is a partial revert of 62cccb8c8e7a ("mm: simplify lock_page_memcg()") but leaves the pageref-holding callsites that aren't affected alone. Link: http://lkml.kernel.org/r/20170809183825.GA26387@cmpxchg.org Fixes: 62cccb8c8e7a ("mm: simplify lock_page_memcg()") Signed-off-by: Johannes Weiner Reported-by: Jaegeuk Kim Tested-by: Jaegeuk Kim Reported-by: Bradley Bolen Tested-by: Brad Bolen Cc: Vladimir Davydov Cc: Michal Hocko Cc: [4.6+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 10 ++++++++-- mm/memcontrol.c | 43 +++++++++++++++++++++++++++++++------------ mm/page-writeback.c | 15 ++++++++++++--- 3 files changed, 51 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 3914e3dd6168..9b15a4bcfa77 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -484,7 +484,8 @@ bool mem_cgroup_oom_synchronize(bool wait); extern int do_swap_account; #endif -void lock_page_memcg(struct page *page); +struct mem_cgroup *lock_page_memcg(struct page *page); +void __unlock_page_memcg(struct mem_cgroup *memcg); void unlock_page_memcg(struct page *page); static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, @@ -809,7 +810,12 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) { } -static inline void lock_page_memcg(struct page *page) +static inline struct mem_cgroup *lock_page_memcg(struct page *page) +{ + return NULL; +} + +static inline void __unlock_page_memcg(struct mem_cgroup *memcg) { } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3df3c04d73ab..e09741af816f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1611,9 +1611,13 @@ cleanup: * @page: the page * * This function protects unlocked LRU pages from being moved to - * another cgroup and stabilizes their page->mem_cgroup binding. + * another cgroup. + * + * It ensures lifetime of the returned memcg. Caller is responsible + * for the lifetime of the page; __unlock_page_memcg() is available + * when @page might get freed inside the locked section. */ -void lock_page_memcg(struct page *page) +struct mem_cgroup *lock_page_memcg(struct page *page) { struct mem_cgroup *memcg; unsigned long flags; @@ -1622,18 +1626,24 @@ void lock_page_memcg(struct page *page) * The RCU lock is held throughout the transaction. The fast * path can get away without acquiring the memcg->move_lock * because page moving starts with an RCU grace period. - */ + * + * The RCU lock also protects the memcg from being freed when + * the page state that is going to change is the only thing + * preventing the page itself from being freed. E.g. writeback + * doesn't hold a page reference and relies on PG_writeback to + * keep off truncation, migration and so forth. + */ rcu_read_lock(); if (mem_cgroup_disabled()) - return; + return NULL; again: memcg = page->mem_cgroup; if (unlikely(!memcg)) - return; + return NULL; if (atomic_read(&memcg->moving_account) <= 0) - return; + return memcg; spin_lock_irqsave(&memcg->move_lock, flags); if (memcg != page->mem_cgroup) { @@ -1649,18 +1659,18 @@ again: memcg->move_lock_task = current; memcg->move_lock_flags = flags; - return; + return memcg; } EXPORT_SYMBOL(lock_page_memcg); /** - * unlock_page_memcg - unlock a page->mem_cgroup binding - * @page: the page + * __unlock_page_memcg - unlock and unpin a memcg + * @memcg: the memcg + * + * Unlock and unpin a memcg returned by lock_page_memcg(). */ -void unlock_page_memcg(struct page *page) +void __unlock_page_memcg(struct mem_cgroup *memcg) { - struct mem_cgroup *memcg = page->mem_cgroup; - if (memcg && memcg->move_lock_task == current) { unsigned long flags = memcg->move_lock_flags; @@ -1672,6 +1682,15 @@ void unlock_page_memcg(struct page *page) rcu_read_unlock(); } + +/** + * unlock_page_memcg - unlock a page->mem_cgroup binding + * @page: the page + */ +void unlock_page_memcg(struct page *page) +{ + __unlock_page_memcg(page->mem_cgroup); +} EXPORT_SYMBOL(unlock_page_memcg); /* diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 96e93b214d31..bf050ab025b7 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2724,9 +2724,12 @@ EXPORT_SYMBOL(clear_page_dirty_for_io); int test_clear_page_writeback(struct page *page) { struct address_space *mapping = page_mapping(page); + struct mem_cgroup *memcg; + struct lruvec *lruvec; int ret; - lock_page_memcg(page); + memcg = lock_page_memcg(page); + lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page)); if (mapping && mapping_use_writeback_tags(mapping)) { struct inode *inode = mapping->host; struct backing_dev_info *bdi = inode_to_bdi(inode); @@ -2754,12 +2757,18 @@ int test_clear_page_writeback(struct page *page) } else { ret = TestClearPageWriteback(page); } + /* + * NOTE: Page might be free now! Writeback doesn't hold a page + * reference on its own, it relies on truncation to wait for + * the clearing of PG_writeback. The below can only access + * page state that is static across allocation cycles. + */ if (ret) { - dec_lruvec_page_state(page, NR_WRITEBACK); + dec_lruvec_state(lruvec, NR_WRITEBACK); dec_zone_page_state(page, NR_ZONE_WRITE_PENDING); inc_node_page_state(page, NR_WRITTEN); } - unlock_page_memcg(page); + __unlock_page_memcg(memcg); return ret; } -- cgit v1.2.3 From 8ada92799ec4de00f4bc0f10b1ededa256c1ab22 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Fri, 18 Aug 2017 15:15:55 -0700 Subject: wait: add wait_event_killable_timeout() These are the few pending fixes I have queued up for v4.13-final. One is a a generic regression fix for recursive loops on kmod and the other one is a trivial print out correction. During the v4.13 development we assumed that recursive kmod loops were no longer possible. Clearly that is not true. The regression fix makes use of a new killable wait. We use a killable wait to be paranoid in how signals might be sent to modprobe and only accept a proper SIGKILL. The signal will only be available to userspace to issue *iff* a thread has already entered a wait state, and that happens only if we've already throttled after 50 kmod threads have been hit. Note that although it may seem excessive to trigger a failure afer 5 seconds if all kmod thread remain busy, prior to the series of changes that went into v4.13 we would actually *always* fatally fail any request which came in if the limit was already reached. The new waiting implemented in v4.13 actually gives us *more* breathing room -- the wait for 5 seconds is a wait for *any* kmod thread to finish. We give up and fail *iff* no kmod thread has finished and they're *all* running straight for 5 consecutive seconds. If 50 kmod threads are running consecutively for 5 seconds something else must be really bad. Recursive loops with kmod are bad but they're also hard to implement properly as a selftest without currently fooling current userspace tools like kmod [1]. For instance kmod will complain when you run depmod if it finds a recursive loop with symbol dependency between modules as such this type of recursive loop cannot go upstream as the modules_install target will fail after running depmod. These tests already exist on userspace kmod upstream though (refer to the testsuite/module-playground/mod-loop-*.c files). The same is not true if request_module() is used though, or worst if aliases are used. Likewise the issue with 64-bit kernels booting 32-bit userspace without a binfmt handler built-in is also currently not detected and proactively avoided by userspace kmod tools, or kconfig for all architectures. Although we could complain in the kernel when some of these individual recursive issues creep up, proactively avoiding these situations in userspace at build time is what we should keep striving for. Lastly, since recursive loops could happen with kmod it may mean recursive loops may also be possible with other kernel usermode helpers, this should be investigated and long term if we can come up with a more sensible generic solution even better! [0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=20170809-kmod-for-v4.13-final [1] https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git This patch (of 3): This wait is similar to wait_event_interruptible_timeout() but only accepts SIGKILL interrupt signal. Other signals are ignored. Link: http://lkml.kernel.org/r/20170809234635.13443-2-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez Acked-by: Peter Zijlstra (Intel) Cc: Ingo Molnar Cc: Kees Cook Cc: Dmitry Torokhov Cc: Jessica Yu Cc: Rusty Russell Cc: Michal Marek Cc: Petr Mladek Cc: Miroslav Benes Cc: Josh Poimboeuf Cc: "Eric W. Biederman" Cc: Shuah Khan Cc: Matt Redfearn Cc: Dan Carpenter Cc: Colin Ian King Cc: Daniel Mentz Cc: David Binderman Cc: Matt Redfearn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/wait.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'include/linux') diff --git a/include/linux/wait.h b/include/linux/wait.h index 5b74e36c0ca8..dc19880c02f5 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -757,6 +757,43 @@ extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *); __ret; \ }) +#define __wait_event_killable_timeout(wq_head, condition, timeout) \ + ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + TASK_KILLABLE, 0, timeout, \ + __ret = schedule_timeout(__ret)) + +/** + * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses + * @wq_head: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * @timeout: timeout, in jiffies + * + * The process is put to sleep (TASK_KILLABLE) until the + * @condition evaluates to true or a kill signal is received. + * The @condition is checked each time the waitqueue @wq_head is woken up. + * + * wake_up() has to be called after changing any variable that could + * change the result of the wait condition. + * + * Returns: + * 0 if the @condition evaluated to %false after the @timeout elapsed, + * 1 if the @condition evaluated to %true after the @timeout elapsed, + * the remaining jiffies (at least 1) if the @condition evaluated + * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was + * interrupted by a kill signal. + * + * Only kill signals interrupt this process. + */ +#define wait_event_killable_timeout(wq_head, condition, timeout) \ +({ \ + long __ret = timeout; \ + might_sleep(); \ + if (!___wait_cond_timeout(condition)) \ + __ret = __wait_event_killable_timeout(wq_head, \ + condition, timeout); \ + __ret; \ +}) + #define __wait_event_lock_irq(wq_head, condition, lock, cmd) \ (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ -- cgit v1.2.3 From 3010f876500f9ba921afaeccec30c45ca6584dc8 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Fri, 18 Aug 2017 15:16:05 -0700 Subject: mm: discard memblock data later There is existing use after free bug when deferred struct pages are enabled: The memblock_add() allocates memory for the memory array if more than 128 entries are needed. See comment in e820__memblock_setup(): * The bootstrap memblock region count maximum is 128 entries * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries * than that - so allow memblock resizing. This memblock memory is freed here: free_low_memory_core_early() We access the freed memblock.memory later in boot when deferred pages are initialized in this path: deferred_init_memmap() for_each_mem_pfn_range() __next_mem_pfn_range() type = &memblock.memory; One possible explanation for why this use-after-free hasn't been hit before is that the limit of INIT_MEMBLOCK_REGIONS has never been exceeded at least on systems where deferred struct pages were enabled. Tested by reducing INIT_MEMBLOCK_REGIONS down to 4 from the current 128, and verifying in qemu that this code is getting excuted and that the freed pages are sane. Link: http://lkml.kernel.org/r/1502485554-318703-2-git-send-email-pasha.tatashin@oracle.com Fixes: 7e18adb4f80b ("mm: meminit: initialise remaining struct pages in parallel with kswapd") Signed-off-by: Pavel Tatashin Reviewed-by: Steven Sistare Reviewed-by: Daniel Jordan Reviewed-by: Bob Picco Acked-by: Michal Hocko Cc: Mel Gorman Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memblock.h | 6 ++++-- mm/memblock.c | 38 +++++++++++++++++--------------------- mm/nobootmem.c | 16 ---------------- mm/page_alloc.c | 4 ++++ 4 files changed, 25 insertions(+), 39 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 77d427974f57..bae11c7e7bf3 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -61,6 +61,7 @@ extern int memblock_debug; #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK #define __init_memblock __meminit #define __initdata_memblock __meminitdata +void memblock_discard(void); #else #define __init_memblock #define __initdata_memblock @@ -74,8 +75,6 @@ phys_addr_t memblock_find_in_range_node(phys_addr_t size, phys_addr_t align, int nid, ulong flags); phys_addr_t memblock_find_in_range(phys_addr_t start, phys_addr_t end, phys_addr_t size, phys_addr_t align); -phys_addr_t get_allocated_memblock_reserved_regions_info(phys_addr_t *addr); -phys_addr_t get_allocated_memblock_memory_regions_info(phys_addr_t *addr); void memblock_allow_resize(void); int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid); int memblock_add(phys_addr_t base, phys_addr_t size); @@ -110,6 +109,9 @@ void __next_mem_range_rev(u64 *idx, int nid, ulong flags, void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start, phys_addr_t *out_end); +void __memblock_free_early(phys_addr_t base, phys_addr_t size); +void __memblock_free_late(phys_addr_t base, phys_addr_t size); + /** * for_each_mem_range - iterate through memblock areas from type_a and not * included in type_b. Or just type_a if type_b is NULL. diff --git a/mm/memblock.c b/mm/memblock.c index 2cb25fe4452c..bf14aea6ab70 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -285,31 +285,27 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u } #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK - -phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info( - phys_addr_t *addr) -{ - if (memblock.reserved.regions == memblock_reserved_init_regions) - return 0; - - *addr = __pa(memblock.reserved.regions); - - return PAGE_ALIGN(sizeof(struct memblock_region) * - memblock.reserved.max); -} - -phys_addr_t __init_memblock get_allocated_memblock_memory_regions_info( - phys_addr_t *addr) +/** + * Discard memory and reserved arrays if they were allocated + */ +void __init memblock_discard(void) { - if (memblock.memory.regions == memblock_memory_init_regions) - return 0; + phys_addr_t addr, size; - *addr = __pa(memblock.memory.regions); + if (memblock.reserved.regions != memblock_reserved_init_regions) { + addr = __pa(memblock.reserved.regions); + size = PAGE_ALIGN(sizeof(struct memblock_region) * + memblock.reserved.max); + __memblock_free_late(addr, size); + } - return PAGE_ALIGN(sizeof(struct memblock_region) * - memblock.memory.max); + if (memblock.memory.regions == memblock_memory_init_regions) { + addr = __pa(memblock.memory.regions); + size = PAGE_ALIGN(sizeof(struct memblock_region) * + memblock.memory.max); + __memblock_free_late(addr, size); + } } - #endif /** diff --git a/mm/nobootmem.c b/mm/nobootmem.c index 36454d0f96ee..3637809a18d0 100644 --- a/mm/nobootmem.c +++ b/mm/nobootmem.c @@ -146,22 +146,6 @@ static unsigned long __init free_low_memory_core_early(void) NULL) count += __free_memory_core(start, end); -#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK - { - phys_addr_t size; - - /* Free memblock.reserved array if it was allocated */ - size = get_allocated_memblock_reserved_regions_info(&start); - if (size) - count += __free_memory_core(start, start + size); - - /* Free memblock.memory array if it was allocated */ - size = get_allocated_memblock_memory_regions_info(&start); - if (size) - count += __free_memory_core(start, start + size); - } -#endif - return count; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6d00f746c2fd..1bad301820c7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1584,6 +1584,10 @@ void __init page_alloc_init_late(void) /* Reinit limits that are based on free pages after the kernel is up */ files_maxfiles_init(); #endif +#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK + /* Discard memblock private memory */ + memblock_discard(); +#endif for_each_populated_zone(zone) set_zone_contiguous(zone); -- cgit v1.2.3 From 6b31d5955cb29a51c5baffee382f213d75e98fb8 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 18 Aug 2017 15:16:15 -0700 Subject: mm, oom: fix potential data corruption when oom_reaper races with writer Wenwei Tao has noticed that our current assumption that the oom victim is dying and never doing any visible changes after it dies, and so the oom_reaper can tear it down, is not entirely true. __task_will_free_mem consider a task dying when SIGNAL_GROUP_EXIT is set but do_group_exit sends SIGKILL to all threads _after_ the flag is set. So there is a race window when some threads won't have fatal_signal_pending while the oom_reaper could start unmapping the address space. Moreover some paths might not check for fatal signals before each PF/g-u-p/copy_from_user. We already have a protection for oom_reaper vs. PF races by checking MMF_UNSTABLE. This has been, however, checked only for kernel threads (use_mm users) which can outlive the oom victim. A simple fix would be to extend the current check in handle_mm_fault for all tasks but that wouldn't be sufficient because the current check assumes that a kernel thread would bail out after EFAULT from get_user*/copy_from_user and never re-read the same address which would succeed because the PF path has established page tables already. This seems to be the case for the only existing use_mm user currently (virtio driver) but it is rather fragile in general. This is even more fragile in general for more complex paths such as generic_perform_write which can re-read the same address more times (e.g. iov_iter_copy_from_user_atomic to fail and then iov_iter_fault_in_readable on retry). Therefore we have to implement MMF_UNSTABLE protection in a robust way and never make a potentially corrupted content visible. That requires to hook deeper into the PF path and check for the flag _every time_ before a pte for anonymous memory is established (that means all !VM_SHARED mappings). The corruption can be triggered artificially (http://lkml.kernel.org/r/201708040646.v746kkhC024636@www262.sakura.ne.jp) but there doesn't seem to be any real life bug report. The race window should be quite tight to trigger most of the time. Link: http://lkml.kernel.org/r/20170807113839.16695-3-mhocko@kernel.org Fixes: aac453635549 ("mm, oom: introduce oom reaper") Signed-off-by: Michal Hocko Reported-by: Wenwei Tao Tested-by: Tetsuo Handa Cc: "Kirill A. Shutemov" Cc: Andrea Argangeli Cc: David Rientjes Cc: Oleg Nesterov Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/oom.h | 22 ++++++++++++++++++++++ mm/huge_memory.c | 30 ++++++++++++++++++++++-------- mm/memory.c | 46 ++++++++++++++++++++-------------------------- 3 files changed, 64 insertions(+), 34 deletions(-) (limited to 'include/linux') diff --git a/include/linux/oom.h b/include/linux/oom.h index 8a266e2be5a6..76aac4ce39bc 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -6,6 +6,8 @@ #include #include #include +#include /* MMF_* */ +#include /* VM_FAULT* */ struct zonelist; struct notifier_block; @@ -63,6 +65,26 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk) return tsk->signal->oom_mm; } +/* + * Checks whether a page fault on the given mm is still reliable. + * This is no longer true if the oom reaper started to reap the + * address space which is reflected by MMF_UNSTABLE flag set in + * the mm. At that moment any !shared mapping would lose the content + * and could cause a memory corruption (zero pages instead of the + * original content). + * + * User should call this before establishing a page table entry for + * a !shared mapping and under the proper page table lock. + * + * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise. + */ +static inline int check_stable_address_space(struct mm_struct *mm) +{ + if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags))) + return VM_FAULT_SIGBUS; + return 0; +} + extern unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 216114f6ef0b..90731e3b7e58 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -550,6 +551,7 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, struct mem_cgroup *memcg; pgtable_t pgtable; unsigned long haddr = vmf->address & HPAGE_PMD_MASK; + int ret = 0; VM_BUG_ON_PAGE(!PageCompound(page), page); @@ -561,9 +563,8 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, pgtable = pte_alloc_one(vma->vm_mm, haddr); if (unlikely(!pgtable)) { - mem_cgroup_cancel_charge(page, memcg, true); - put_page(page); - return VM_FAULT_OOM; + ret = VM_FAULT_OOM; + goto release; } clear_huge_page(page, haddr, HPAGE_PMD_NR); @@ -576,13 +577,14 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); if (unlikely(!pmd_none(*vmf->pmd))) { - spin_unlock(vmf->ptl); - mem_cgroup_cancel_charge(page, memcg, true); - put_page(page); - pte_free(vma->vm_mm, pgtable); + goto unlock_release; } else { pmd_t entry; + ret = check_stable_address_space(vma->vm_mm); + if (ret) + goto unlock_release; + /* Deliver the page fault to userland */ if (userfaultfd_missing(vma)) { int ret; @@ -610,6 +612,15 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, } return 0; +unlock_release: + spin_unlock(vmf->ptl); +release: + if (pgtable) + pte_free(vma->vm_mm, pgtable); + mem_cgroup_cancel_charge(page, memcg, true); + put_page(page); + return ret; + } /* @@ -688,7 +699,10 @@ int do_huge_pmd_anonymous_page(struct vm_fault *vmf) ret = 0; set = false; if (pmd_none(*vmf->pmd)) { - if (userfaultfd_missing(vma)) { + ret = check_stable_address_space(vma->vm_mm); + if (ret) { + spin_unlock(vmf->ptl); + } else if (userfaultfd_missing(vma)) { spin_unlock(vmf->ptl); ret = handle_userfault(vmf, VM_UFFD_MISSING); VM_BUG_ON(ret & VM_FAULT_FALLBACK); diff --git a/mm/memory.c b/mm/memory.c index c717b5bcc80e..fe2fba27ded2 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -68,6 +68,7 @@ #include #include #include +#include #include #include @@ -2893,6 +2894,7 @@ static int do_anonymous_page(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; struct mem_cgroup *memcg; struct page *page; + int ret = 0; pte_t entry; /* File mapping without ->vm_ops ? */ @@ -2925,6 +2927,9 @@ static int do_anonymous_page(struct vm_fault *vmf) vmf->address, &vmf->ptl); if (!pte_none(*vmf->pte)) goto unlock; + ret = check_stable_address_space(vma->vm_mm); + if (ret) + goto unlock; /* Deliver the page fault to userland, check inside PT lock */ if (userfaultfd_missing(vma)) { pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -2959,6 +2964,10 @@ static int do_anonymous_page(struct vm_fault *vmf) if (!pte_none(*vmf->pte)) goto release; + ret = check_stable_address_space(vma->vm_mm); + if (ret) + goto release; + /* Deliver the page fault to userland, check inside PT lock */ if (userfaultfd_missing(vma)) { pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -2978,7 +2987,7 @@ setpte: update_mmu_cache(vma, vmf->address, vmf->pte); unlock: pte_unmap_unlock(vmf->pte, vmf->ptl); - return 0; + return ret; release: mem_cgroup_cancel_charge(page, memcg, false); put_page(page); @@ -3252,7 +3261,7 @@ int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg, int finish_fault(struct vm_fault *vmf) { struct page *page; - int ret; + int ret = 0; /* Did we COW the page? */ if ((vmf->flags & FAULT_FLAG_WRITE) && @@ -3260,7 +3269,15 @@ int finish_fault(struct vm_fault *vmf) page = vmf->cow_page; else page = vmf->page; - ret = alloc_set_pte(vmf, vmf->memcg, page); + + /* + * check even for read faults because we might have lost our CoWed + * page + */ + if (!(vmf->vma->vm_flags & VM_SHARED)) + ret = check_stable_address_space(vmf->vma->vm_mm); + if (!ret) + ret = alloc_set_pte(vmf, vmf->memcg, page); if (vmf->pte) pte_unmap_unlock(vmf->pte, vmf->ptl); return ret; @@ -3900,29 +3917,6 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address, mem_cgroup_oom_synchronize(false); } - /* - * This mm has been already reaped by the oom reaper and so the - * refault cannot be trusted in general. Anonymous refaults would - * lose data and give a zero page instead e.g. This is especially - * problem for use_mm() because regular tasks will just die and - * the corrupted data will not be visible anywhere while kthread - * will outlive the oom victim and potentially propagate the date - * further. - */ - if (unlikely((current->flags & PF_KTHREAD) && !(ret & VM_FAULT_ERROR) - && test_bit(MMF_UNSTABLE, &vma->vm_mm->flags))) { - - /* - * We are going to enforce SIGBUS but the PF path might have - * dropped the mmap_sem already so take it again so that - * we do not break expectations of all arch specific PF paths - * and g-u-p - */ - if (ret & VM_FAULT_RETRY) - down_read(&vma->vm_mm->mmap_sem); - ret = VM_FAULT_SIGBUS; - } - return ret; } EXPORT_SYMBOL_GPL(handle_mm_fault); -- cgit v1.2.3 From dd1c1f2f2028a7b851f701fc6a8ebe39dcb95e7c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 21 Aug 2017 17:35:02 +0200 Subject: pids: make task_tgid_nr_ns() safe This was reported many times, and this was even mentioned in commit 52ee2dfdd4f5 ("pids: refactor vnr/nr_ns helpers to make them safe") but somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is not safe because task->group_leader points to nowhere after the exiting task passes exit_notify(), rcu_read_lock() can not help. We really need to change __unhash_process() to nullify group_leader, parent, and real_parent, but this needs some cleanups. Until then we can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and fix the problem. Reported-by: Troy Kensinger Signed-off-by: Oleg Nesterov Signed-off-by: Linus Torvalds --- include/linux/pid.h | 4 +++- include/linux/sched.h | 51 +++++++++++++++++++++++++++------------------------ kernel/pid.c | 11 ++++------- 3 files changed, 34 insertions(+), 32 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pid.h b/include/linux/pid.h index 4d179316e431..719582744a2e 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -8,7 +8,9 @@ enum pid_type PIDTYPE_PID, PIDTYPE_PGID, PIDTYPE_SID, - PIDTYPE_MAX + PIDTYPE_MAX, + /* only valid to __task_pid_nr_ns() */ + __PIDTYPE_TGID }; /* diff --git a/include/linux/sched.h b/include/linux/sched.h index 8337e2db0bb2..c05ac5f5aa03 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1163,13 +1163,6 @@ static inline pid_t task_tgid_nr(struct task_struct *tsk) return tsk->tgid; } -extern pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns); - -static inline pid_t task_tgid_vnr(struct task_struct *tsk) -{ - return pid_vnr(task_tgid(tsk)); -} - /** * pid_alive - check that a task structure is not stale * @p: Task structure to be checked. @@ -1185,23 +1178,6 @@ static inline int pid_alive(const struct task_struct *p) return p->pids[PIDTYPE_PID].pid != NULL; } -static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) -{ - pid_t pid = 0; - - rcu_read_lock(); - if (pid_alive(tsk)) - pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); - rcu_read_unlock(); - - return pid; -} - -static inline pid_t task_ppid_nr(const struct task_struct *tsk) -{ - return task_ppid_nr_ns(tsk, &init_pid_ns); -} - static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) { return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); @@ -1223,6 +1199,33 @@ static inline pid_t task_session_vnr(struct task_struct *tsk) return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); } +static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) +{ + return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns); +} + +static inline pid_t task_tgid_vnr(struct task_struct *tsk) +{ + return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL); +} + +static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) +{ + pid_t pid = 0; + + rcu_read_lock(); + if (pid_alive(tsk)) + pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); + rcu_read_unlock(); + + return pid; +} + +static inline pid_t task_ppid_nr(const struct task_struct *tsk) +{ + return task_ppid_nr_ns(tsk, &init_pid_ns); +} + /* Obsolete, do not use: */ static inline pid_t task_pgrp_nr(struct task_struct *tsk) { diff --git a/kernel/pid.c b/kernel/pid.c index c69c30d827e5..020dedbdf066 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -527,8 +527,11 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, if (!ns) ns = task_active_pid_ns(current); if (likely(pid_alive(task))) { - if (type != PIDTYPE_PID) + if (type != PIDTYPE_PID) { + if (type == __PIDTYPE_TGID) + type = PIDTYPE_PID; task = task->group_leader; + } nr = pid_nr_ns(rcu_dereference(task->pids[type].pid), ns); } rcu_read_unlock(); @@ -537,12 +540,6 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, } EXPORT_SYMBOL(__task_pid_nr_ns); -pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) -{ - return pid_nr_ns(task_tgid(tsk), ns); -} -EXPORT_SYMBOL(task_tgid_nr_ns); - struct pid_namespace *task_active_pid_ns(struct task_struct *tsk) { return ns_of_pid(task_pid(tsk)); -- cgit v1.2.3 From 143c97cc652949893c8056c679012f0aeccb80e5 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 23 Aug 2017 18:16:11 -0700 Subject: Revert "pty: fix the cached path of the pty slave file descriptor in the master" This reverts commit c8c03f1858331e85d397bacccd34ef409aae993c. It turns out that while fixing the ptmx file descriptor to have the correct 'struct path' to the associated slave pty is a really good thing, it breaks some user space tools for a very annoying reason. The problem is that /dev/ptmx and its associated slave pty (/dev/pts/X) are on different mounts. That was what caused us to have the wrong path in the first place (we would mix up the vfsmount of the 'ptmx' node, with the dentry of the pty slave node), but it also means that now while we use the right vfsmount, having the pty master open also keeps the pts mount busy. And it turn sout that that makes 'pbuilder' very unhappy, as noted by Stefan Lippers-Hollmann: "This patch introduces a regression for me when using pbuilder 0.228.7[2] (a helper to build Debian packages in a chroot and to create and update its chroots) when trying to umount /dev/ptmx (inside the chroot) on Debian/ unstable (full log and pbuilder configuration file[3] attached). [...] Setting up build-essential (12.3) ... Processing triggers for libc-bin (2.24-15) ... I: unmounting dev/ptmx filesystem W: Could not unmount dev/ptmx: umount: /var/cache/pbuilder/build/1340/dev/ptmx: target is busy (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1).)" apparently pbuilder tries to unmount the /dev/pts filesystem while still holding at least one master node open, which is arguably not very nice, but we don't break user space even when fixing other bugs. So this commit has to be reverted. I'll try to figure out a way to avoid caching the path to the slave pty in the master pty. The only thing that actually wants that slave pty path is the "TIOCGPTPEER" ioctl, and I think we could just recreate the path at that time. Reported-by: Stefan Lippers-Hollmann Cc: Eric W Biederman Cc: Christian Brauner Cc: Al Viro Signed-off-by: Linus Torvalds --- drivers/tty/pty.c | 7 ++----- fs/devpts/inode.c | 4 +--- include/linux/devpts_fs.h | 2 +- 3 files changed, 4 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 1fc80ea87c13..284749fb0f6b 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -793,7 +793,6 @@ static int ptmx_open(struct inode *inode, struct file *filp) struct tty_struct *tty; struct path *pts_path; struct dentry *dentry; - struct vfsmount *mnt; int retval; int index; @@ -806,7 +805,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) return retval; - fsi = devpts_acquire(filp, &mnt); + fsi = devpts_acquire(filp); if (IS_ERR(fsi)) { retval = PTR_ERR(fsi); goto out_free_file; @@ -850,7 +849,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) pts_path = kmalloc(sizeof(struct path), GFP_KERNEL); if (!pts_path) goto err_release; - pts_path->mnt = mnt; + pts_path->mnt = filp->f_path.mnt; pts_path->dentry = dentry; path_get(pts_path); tty->link->driver_data = pts_path; @@ -867,7 +866,6 @@ err_path_put: path_put(pts_path); kfree(pts_path); err_release: - mntput(mnt); tty_unlock(tty); // This will also put-ref the fsi tty_release(inode, filp); @@ -876,7 +874,6 @@ out: devpts_kill_index(fsi, index); out_put_fsi: devpts_release(fsi); - mntput(mnt); out_free_file: tty_free_file(filp); return retval; diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 44dfbca9306f..108df2e3602c 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -133,7 +133,7 @@ static inline struct pts_fs_info *DEVPTS_SB(struct super_block *sb) return sb->s_fs_info; } -struct pts_fs_info *devpts_acquire(struct file *filp, struct vfsmount **ptsmnt) +struct pts_fs_info *devpts_acquire(struct file *filp) { struct pts_fs_info *result; struct path path; @@ -142,7 +142,6 @@ struct pts_fs_info *devpts_acquire(struct file *filp, struct vfsmount **ptsmnt) path = filp->f_path; path_get(&path); - *ptsmnt = NULL; /* Has the devpts filesystem already been found? */ sb = path.mnt->mnt_sb; @@ -166,7 +165,6 @@ struct pts_fs_info *devpts_acquire(struct file *filp, struct vfsmount **ptsmnt) * pty code needs to hold extra references in case of last /dev/tty close */ atomic_inc(&sb->s_active); - *ptsmnt = mntget(path.mnt); result = DEVPTS_SB(sb); out: diff --git a/include/linux/devpts_fs.h b/include/linux/devpts_fs.h index 7883e901f65c..277ab9af9ac2 100644 --- a/include/linux/devpts_fs.h +++ b/include/linux/devpts_fs.h @@ -19,7 +19,7 @@ struct pts_fs_info; -struct pts_fs_info *devpts_acquire(struct file *, struct vfsmount **ptsmnt); +struct pts_fs_info *devpts_acquire(struct file *); void devpts_release(struct pts_fs_info *); int devpts_new_index(struct pts_fs_info *); -- cgit v1.2.3 From 311fc65c9fb9c966bca8e6f3ff8132ce57344ab9 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 24 Aug 2017 15:13:29 -0500 Subject: pty: Repair TIOCGPTPEER The implementation of TIOCGPTPEER has two issues. When /dev/ptmx (as opposed to /dev/pts/ptmx) is opened the wrong vfsmount is passed to dentry_open. Which results in the kernel displaying the wrong pathname for the peer. The second is simply by caching the vfsmount and dentry of the peer it leaves them open, in a way they were not previously Which because of the inreased reference counts can cause unnecessary behaviour differences resulting in regressions. To fix these move the ioctl into tty_io.c at a generic level allowing the ioctl to have access to the struct file on which the ioctl is being called. This allows the path of the slave to be derived when opening the slave through TIOCGPTPEER instead of requiring the path to the slave be cached. Thus removing the need for caching the path. A new function devpts_ptmx_path is factored out of devpts_acquire and used to implement a function devpts_mntget. The new function devpts_mntget takes a filp to perform the lookup on and fsi so that it can confirm that the superblock that is found by devpts_ptmx_path is the proper superblock. v2: Lots of fixes to make the code actually work v3: Suggestions by Linus - Removed the unnecessary initialization of filp in ptm_open_peer - Simplified devpts_ptmx_path as gotos are no longer required [ This is the fix for the issue that was reverted in commit 143c97cc6529, but this time without breaking 'pbuilder' due to increased reference counts - Linus ] Fixes: 54ebbfb16034 ("tty: add TIOCGPTPEER ioctl") Reported-by: Christian Brauner Reported-and-tested-by: Stefan Lippers-Hollmann Signed-off-by: "Eric W. Biederman" Signed-off-by: Linus Torvalds --- drivers/tty/pty.c | 64 ++++++++++++++++++++-------------------------- drivers/tty/tty_io.c | 3 +++ fs/devpts/inode.c | 65 +++++++++++++++++++++++++++++++++++------------ include/linux/devpts_fs.h | 10 ++++++++ 4 files changed, 89 insertions(+), 53 deletions(-) (limited to 'include/linux') diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 284749fb0f6b..a6d5164c33a9 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -69,13 +69,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp) #ifdef CONFIG_UNIX98_PTYS if (tty->driver == ptm_driver) { mutex_lock(&devpts_mutex); - if (tty->link->driver_data) { - struct path *path = tty->link->driver_data; - - devpts_pty_kill(path->dentry); - path_put(path); - kfree(path); - } + if (tty->link->driver_data) + devpts_pty_kill(tty->link->driver_data); mutex_unlock(&devpts_mutex); } #endif @@ -607,25 +602,24 @@ static inline void legacy_pty_init(void) { } static struct cdev ptmx_cdev; /** - * pty_open_peer - open the peer of a pty - * @tty: the peer of the pty being opened + * ptm_open_peer - open the peer of a pty + * @master: the open struct file of the ptmx device node + * @tty: the master of the pty being opened + * @flags: the flags for open * - * Open the cached dentry in tty->link, providing a safe way for userspace - * to get the slave end of a pty (where they have the master fd and cannot - * access or trust the mount namespace /dev/pts was mounted inside). + * Provide a race free way for userspace to open the slave end of a pty + * (where they have the master fd and cannot access or trust the mount + * namespace /dev/pts was mounted inside). */ -static struct file *pty_open_peer(struct tty_struct *tty, int flags) -{ - if (tty->driver->subtype != PTY_TYPE_MASTER) - return ERR_PTR(-EIO); - return dentry_open(tty->link->driver_data, flags, current_cred()); -} - -static int pty_get_peer(struct tty_struct *tty, int flags) +int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags) { int fd = -1; - struct file *filp = NULL; + struct file *filp; int retval = -EINVAL; + struct path path; + + if (tty->driver != ptm_driver) + return -EIO; fd = get_unused_fd_flags(0); if (fd < 0) { @@ -633,7 +627,16 @@ static int pty_get_peer(struct tty_struct *tty, int flags) goto err; } - filp = pty_open_peer(tty, flags); + /* Compute the slave's path */ + path.mnt = devpts_mntget(master, tty->driver_data); + if (IS_ERR(path.mnt)) { + retval = PTR_ERR(path.mnt); + goto err_put; + } + path.dentry = tty->link->driver_data; + + filp = dentry_open(&path, flags, current_cred()); + mntput(path.mnt); if (IS_ERR(filp)) { retval = PTR_ERR(filp); goto err_put; @@ -662,8 +665,6 @@ static int pty_unix98_ioctl(struct tty_struct *tty, return pty_get_pktmode(tty, (int __user *)arg); case TIOCGPTN: /* Get PT Number */ return put_user(tty->index, (unsigned int __user *)arg); - case TIOCGPTPEER: /* Open the other end */ - return pty_get_peer(tty, (int) arg); case TIOCSIG: /* Send signal to other side of pty */ return pty_signal(tty, (int) arg); } @@ -791,7 +792,6 @@ static int ptmx_open(struct inode *inode, struct file *filp) { struct pts_fs_info *fsi; struct tty_struct *tty; - struct path *pts_path; struct dentry *dentry; int retval; int index; @@ -845,26 +845,16 @@ static int ptmx_open(struct inode *inode, struct file *filp) retval = PTR_ERR(dentry); goto err_release; } - /* We need to cache a fake path for TIOCGPTPEER. */ - pts_path = kmalloc(sizeof(struct path), GFP_KERNEL); - if (!pts_path) - goto err_release; - pts_path->mnt = filp->f_path.mnt; - pts_path->dentry = dentry; - path_get(pts_path); - tty->link->driver_data = pts_path; + tty->link->driver_data = dentry; retval = ptm_driver->ops->open(tty, filp); if (retval) - goto err_path_put; + goto err_release; tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); tty_unlock(tty); return 0; -err_path_put: - path_put(pts_path); - kfree(pts_path); err_release: tty_unlock(tty); // This will also put-ref the fsi diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 974b13d24401..10c4038c0e8d 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2518,6 +2518,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case TIOCSSERIAL: tty_warn_deprecated_flags(p); break; + case TIOCGPTPEER: + /* Special because the struct file is needed */ + return ptm_open_peer(file, tty, (int)arg); default: retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); if (retval != -ENOIOCTLCMD) diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 108df2e3602c..7eae33ffa3fc 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -133,6 +133,50 @@ static inline struct pts_fs_info *DEVPTS_SB(struct super_block *sb) return sb->s_fs_info; } +static int devpts_ptmx_path(struct path *path) +{ + struct super_block *sb; + int err; + + /* Has the devpts filesystem already been found? */ + if (path->mnt->mnt_sb->s_magic == DEVPTS_SUPER_MAGIC) + return 0; + + /* Is a devpts filesystem at "pts" in the same directory? */ + err = path_pts(path); + if (err) + return err; + + /* Is the path the root of a devpts filesystem? */ + sb = path->mnt->mnt_sb; + if ((sb->s_magic != DEVPTS_SUPER_MAGIC) || + (path->mnt->mnt_root != sb->s_root)) + return -ENODEV; + + return 0; +} + +struct vfsmount *devpts_mntget(struct file *filp, struct pts_fs_info *fsi) +{ + struct path path; + int err; + + path = filp->f_path; + path_get(&path); + + err = devpts_ptmx_path(&path); + dput(path.dentry); + if (err) { + mntput(path.mnt); + path.mnt = ERR_PTR(err); + } + if (DEVPTS_SB(path.mnt->mnt_sb) != fsi) { + mntput(path.mnt); + path.mnt = ERR_PTR(-ENODEV); + } + return path.mnt; +} + struct pts_fs_info *devpts_acquire(struct file *filp) { struct pts_fs_info *result; @@ -143,27 +187,16 @@ struct pts_fs_info *devpts_acquire(struct file *filp) path = filp->f_path; path_get(&path); - /* Has the devpts filesystem already been found? */ - sb = path.mnt->mnt_sb; - if (sb->s_magic != DEVPTS_SUPER_MAGIC) { - /* Is a devpts filesystem at "pts" in the same directory? */ - err = path_pts(&path); - if (err) { - result = ERR_PTR(err); - goto out; - } - - /* Is the path the root of a devpts filesystem? */ - result = ERR_PTR(-ENODEV); - sb = path.mnt->mnt_sb; - if ((sb->s_magic != DEVPTS_SUPER_MAGIC) || - (path.mnt->mnt_root != sb->s_root)) - goto out; + err = devpts_ptmx_path(&path); + if (err) { + result = ERR_PTR(err); + goto out; } /* * pty code needs to hold extra references in case of last /dev/tty close */ + sb = path.mnt->mnt_sb; atomic_inc(&sb->s_active); result = DEVPTS_SB(sb); diff --git a/include/linux/devpts_fs.h b/include/linux/devpts_fs.h index 277ab9af9ac2..100cb4343763 100644 --- a/include/linux/devpts_fs.h +++ b/include/linux/devpts_fs.h @@ -19,6 +19,7 @@ struct pts_fs_info; +struct vfsmount *devpts_mntget(struct file *, struct pts_fs_info *); struct pts_fs_info *devpts_acquire(struct file *); void devpts_release(struct pts_fs_info *); @@ -32,6 +33,15 @@ void *devpts_get_priv(struct dentry *); /* unlink */ void devpts_pty_kill(struct dentry *); +/* in pty.c */ +int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags); + +#else +static inline int +ptm_open_peer(struct file *master, struct tty_struct *tty, int flags) +{ + return -EIO; +} #endif -- cgit v1.2.3