From 06709e81c668f5f56c65b806895b278517bd44e0 Mon Sep 17 00:00:00 2001 From: John Garry Date: Tue, 30 Jul 2019 21:29:52 +0800 Subject: lib: logic_pio: Fix RCU usage The traversing of io_range_list with list_for_each_entry_rcu() is not properly protected by rcu_read_lock() and rcu_read_unlock(), so add them. These functions mark the critical section scope where the list is protected for the reader, it cannot be "reclaimed". Any updater - in this case, the logical PIO registration functions - cannot update the list until the reader exits this critical section. In addition, the list traversing used in logic_pio_register_range() does not need to use the rcu variant. This is because we are already using io_range_mutex to guarantee mutual exclusion from mutating the list. Cc: stable@vger.kernel.org Fixes: 031e3601869c ("lib: Add generic PIO mapping method") Signed-off-by: John Garry Signed-off-by: Wei Xu --- lib/logic_pio.c | 49 +++++++++++++++++++++++++++++++++++-------------- 1 file changed, 35 insertions(+), 14 deletions(-) diff --git a/lib/logic_pio.c b/lib/logic_pio.c index feea48fd1a0d..761296376fbc 100644 --- a/lib/logic_pio.c +++ b/lib/logic_pio.c @@ -46,7 +46,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) end = new_range->hw_start + new_range->size; mutex_lock(&io_range_mutex); - list_for_each_entry_rcu(range, &io_range_list, list) { + list_for_each_entry(range, &io_range_list, list) { if (range->fwnode == new_range->fwnode) { /* range already there */ goto end_register; @@ -108,26 +108,38 @@ end_register: */ struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode) { - struct logic_pio_hwaddr *range; + struct logic_pio_hwaddr *range, *found_range = NULL; + rcu_read_lock(); list_for_each_entry_rcu(range, &io_range_list, list) { - if (range->fwnode == fwnode) - return range; + if (range->fwnode == fwnode) { + found_range = range; + break; + } } - return NULL; + rcu_read_unlock(); + + return found_range; } /* Return a registered range given an input PIO token */ static struct logic_pio_hwaddr *find_io_range(unsigned long pio) { - struct logic_pio_hwaddr *range; + struct logic_pio_hwaddr *range, *found_range = NULL; + rcu_read_lock(); list_for_each_entry_rcu(range, &io_range_list, list) { - if (in_range(pio, range->io_start, range->size)) - return range; + if (in_range(pio, range->io_start, range->size)) { + found_range = range; + break; + } } - pr_err("PIO entry token %lx invalid\n", pio); - return NULL; + rcu_read_unlock(); + + if (!found_range) + pr_err("PIO entry token 0x%lx invalid\n", pio); + + return found_range; } /** @@ -180,14 +192,23 @@ unsigned long logic_pio_trans_cpuaddr(resource_size_t addr) { struct logic_pio_hwaddr *range; + rcu_read_lock(); list_for_each_entry_rcu(range, &io_range_list, list) { if (range->flags != LOGIC_PIO_CPU_MMIO) continue; - if (in_range(addr, range->hw_start, range->size)) - return addr - range->hw_start + range->io_start; + if (in_range(addr, range->hw_start, range->size)) { + unsigned long cpuaddr; + + cpuaddr = addr - range->hw_start + range->io_start; + + rcu_read_unlock(); + return cpuaddr; + } } - pr_err("addr %llx not registered in io_range_list\n", - (unsigned long long) addr); + rcu_read_unlock(); + + pr_err("addr %pa not registered in io_range_list\n", &addr); + return ~0UL; } -- cgit v1.2.3-59-g8ed1b From 0a27142bd1ee259e24a0be2b0133e5ca5df8da91 Mon Sep 17 00:00:00 2001 From: John Garry Date: Tue, 30 Jul 2019 21:29:53 +0800 Subject: lib: logic_pio: Avoid possible overlap for unregistering regions The code was originally written to not support unregistering logical PIO regions. To accommodate supporting unregistering logical PIO regions, subtly modify LOGIC_PIO_CPU_MMIO region registration code, such that the "end" of the registered regions is the "end" of the last region, and not the sum of the sizes of all the registered regions. Cc: stable@vger.kernel.org Signed-off-by: John Garry Signed-off-by: Wei Xu --- lib/logic_pio.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/lib/logic_pio.c b/lib/logic_pio.c index 761296376fbc..d0165c88f705 100644 --- a/lib/logic_pio.c +++ b/lib/logic_pio.c @@ -35,7 +35,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) struct logic_pio_hwaddr *range; resource_size_t start; resource_size_t end; - resource_size_t mmio_sz = 0; + resource_size_t mmio_end = 0; resource_size_t iio_sz = MMIO_UPPER_LIMIT; int ret = 0; @@ -56,7 +56,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) /* for MMIO ranges we need to check for overlap */ if (start >= range->hw_start + range->size || end < range->hw_start) { - mmio_sz += range->size; + mmio_end = range->io_start + range->size; } else { ret = -EFAULT; goto end_register; @@ -69,16 +69,16 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) /* range not registered yet, check for available space */ if (new_range->flags == LOGIC_PIO_CPU_MMIO) { - if (mmio_sz + new_range->size - 1 > MMIO_UPPER_LIMIT) { + if (mmio_end + new_range->size - 1 > MMIO_UPPER_LIMIT) { /* if it's too big check if 64K space can be reserved */ - if (mmio_sz + SZ_64K - 1 > MMIO_UPPER_LIMIT) { + if (mmio_end + SZ_64K - 1 > MMIO_UPPER_LIMIT) { ret = -E2BIG; goto end_register; } new_range->size = SZ_64K; pr_warn("Requested IO range too big, new size set to 64K\n"); } - new_range->io_start = mmio_sz; + new_range->io_start = mmio_end; } else if (new_range->flags == LOGIC_PIO_INDIRECT) { if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) { ret = -E2BIG; -- cgit v1.2.3-59-g8ed1b From b884e2de2afc68ce30f7093747378ef972dde253 Mon Sep 17 00:00:00 2001 From: John Garry Date: Tue, 30 Jul 2019 21:29:54 +0800 Subject: lib: logic_pio: Add logic_pio_unregister_range() Add a function to unregister a logical PIO range. Logical PIO space can still be leaked when unregistering certain LOGIC_PIO_CPU_MMIO regions, but this acceptable for now since there are no callers to unregister LOGIC_PIO_CPU_MMIO regions, and the logical PIO region allocation scheme would need significant work to improve this. Cc: stable@vger.kernel.org Signed-off-by: John Garry Signed-off-by: Wei Xu --- include/linux/logic_pio.h | 1 + lib/logic_pio.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/logic_pio.h b/include/linux/logic_pio.h index cbd9d8495690..88e1e6304a71 100644 --- a/include/linux/logic_pio.h +++ b/include/linux/logic_pio.h @@ -117,6 +117,7 @@ struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode); unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode, resource_size_t hw_addr, resource_size_t size); int logic_pio_register_range(struct logic_pio_hwaddr *newrange); +void logic_pio_unregister_range(struct logic_pio_hwaddr *range); resource_size_t logic_pio_to_hwaddr(unsigned long pio); unsigned long logic_pio_trans_cpuaddr(resource_size_t hw_addr); diff --git a/lib/logic_pio.c b/lib/logic_pio.c index d0165c88f705..905027574e5d 100644 --- a/lib/logic_pio.c +++ b/lib/logic_pio.c @@ -98,6 +98,20 @@ end_register: return ret; } +/** + * logic_pio_unregister_range - unregister a logical PIO range for a host + * @range: pointer to the IO range which has been already registered. + * + * Unregister a previously-registered IO range node. + */ +void logic_pio_unregister_range(struct logic_pio_hwaddr *range) +{ + mutex_lock(&io_range_mutex); + list_del_rcu(&range->list); + mutex_unlock(&io_range_mutex); + synchronize_rcu(); +} + /** * find_io_range_by_fwnode - find logical PIO range for given FW node * @fwnode: FW node handle associated with logical PIO range -- cgit v1.2.3-59-g8ed1b From 1b15a5632a809ab57d403fd972ca68785363b654 Mon Sep 17 00:00:00 2001 From: John Garry Date: Tue, 30 Jul 2019 21:29:55 +0800 Subject: bus: hisi_lpc: Unregister logical PIO range to avoid potential use-after-free If, after registering a logical PIO range, the driver probe later fails, the logical PIO range memory will be released automatically. This causes an issue, in that the logical PIO range is not unregistered and the released range memory may be later referenced. Fix by unregistering the logical PIO range. And since we now unregister the logical PIO range for probe failure, avoid the special ordering of setting logical PIO range ops, which was the previous (poor) attempt at a safeguard against this. Cc: stable@vger.kernel.org Fixes: adf38bb0b595 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings") Signed-off-by: John Garry Signed-off-by: Wei Xu --- drivers/bus/hisi_lpc.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c index 19d7b6ff2f17..6d301aafcad2 100644 --- a/drivers/bus/hisi_lpc.c +++ b/drivers/bus/hisi_lpc.c @@ -606,24 +606,25 @@ static int hisi_lpc_probe(struct platform_device *pdev) range->fwnode = dev->fwnode; range->flags = LOGIC_PIO_INDIRECT; range->size = PIO_INDIRECT_SIZE; + range->hostdata = lpcdev; + range->ops = &hisi_lpc_ops; + lpcdev->io_host = range; ret = logic_pio_register_range(range); if (ret) { dev_err(dev, "register IO range failed (%d)!\n", ret); return ret; } - lpcdev->io_host = range; /* register the LPC host PIO resources */ if (acpi_device) ret = hisi_lpc_acpi_probe(dev); else ret = of_platform_populate(dev->of_node, NULL, NULL, dev); - if (ret) + if (ret) { + logic_pio_unregister_range(range); return ret; - - lpcdev->io_host->hostdata = lpcdev; - lpcdev->io_host->ops = &hisi_lpc_ops; + } io_end = lpcdev->io_host->io_start + lpcdev->io_host->size; dev_info(dev, "registered range [%pa - %pa]\n", -- cgit v1.2.3-59-g8ed1b From 10e62b47973b0b0ceda076255bcb147b83e20517 Mon Sep 17 00:00:00 2001 From: John Garry Date: Tue, 30 Jul 2019 21:29:56 +0800 Subject: bus: hisi_lpc: Add .remove method to avoid driver unbind crash The original driver author seemed to be under the impression that a driver cannot be removed if it does not have a .remove method. Or maybe if it is a built-in platform driver. This is not true. This crash can be created: root@ubuntu:/sys/bus/platform/drivers/hisi-lpc# echo HISI0191\:00 > unbind root@ubuntu:/sys/bus/platform/drivers/hisi-lpc# ipmitool raw 6 1 Unable to handle kernel paging request at virtual address ffff000010035010 Mem abort info: ESR = 0x96000047 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000047 CM = 0, WnR = 1 swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000000118b000 [ffff000010035010] pgd=0000041ffbfff003, pud=0000041ffbffe003, pmd=0000041ffbffd003, pte=0000000000000000 Internal error: Oops: 96000047 [#1] PREEMPT SMP Modules linked in: CPU: 17 PID: 1473 Comm: ipmitool Not tainted 5.2.0-rc5-00003-gf68c53b414a3-dirty #198 Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018 pstate: 20000085 (nzCv daIf -PAN -UAO) pc : hisi_lpc_target_in+0x7c/0x120 lr : hisi_lpc_target_in+0x70/0x120 sp : ffff00001efe3930 x29: ffff00001efe3930 x28: ffff841f9f599200 x27: 0000000000000002 x26: 0000000000000000 x25: 0000000000000080 x24: 00000000000000e4 x23: 0000000000000000 x22: 0000000000000064 x21: ffff801fb667d280 x20: 0000000000000001 x19: ffff00001efe39ac x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : ffff841febe60340 x7 : ffff801fb55c52e8 x6 : 0000000000000000 x5 : 0000000000ffc0e3 x4 : 0000000000000001 x3 : ffff801fb667d280 x2 : 0000000000000001 x1 : ffff000010035010 x0 : ffff000010035000 Call trace: hisi_lpc_target_in+0x7c/0x120 hisi_lpc_comm_in+0x88/0x98 logic_inb+0x5c/0xb8 port_inb+0x18/0x20 bt_event+0x38/0x808 smi_event_handler+0x4c/0x5a0 check_start_timer_thread.part.4+0x40/0x58 sender+0x78/0x88 smi_send.isra.6+0x94/0x108 i_ipmi_request+0x2c4/0x8f8 ipmi_request_settime+0x124/0x160 handle_send_req+0x19c/0x208 ipmi_ioctl+0x2c0/0x990 do_vfs_ioctl+0xb8/0x8f8 ksys_ioctl+0x80/0xb8 __arm64_sys_ioctl+0x1c/0x28 el0_svc_common.constprop.0+0x64/0x160 el0_svc_handler+0x28/0x78 el0_svc+0x8/0xc Code: 941d1511 aa0003f9 f94006a0 91004001 (b9000034) ---[ end trace aa842b86af7069e4 ]--- The problem here is that the host goes away but the associated logical PIO region remains registered, as do the children devices. Fix by adding a .remove method to tidy-up by removing the child devices and unregistering the logical PIO region. Cc: stable@vger.kernel.org Fixes: adf38bb0b595 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings") Signed-off-by: John Garry Signed-off-by: Wei Xu --- drivers/bus/hisi_lpc.c | 38 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c index 6d301aafcad2..20c957185af2 100644 --- a/drivers/bus/hisi_lpc.c +++ b/drivers/bus/hisi_lpc.c @@ -456,6 +456,17 @@ struct hisi_lpc_acpi_cell { size_t pdata_size; }; +static void hisi_lpc_acpi_remove(struct device *hostdev) +{ + struct acpi_device *adev = ACPI_COMPANION(hostdev); + struct acpi_device *child; + + device_for_each_child(hostdev, NULL, hisi_lpc_acpi_remove_subdev); + + list_for_each_entry(child, &adev->children, node) + acpi_device_clear_enumerated(child); +} + /* * hisi_lpc_acpi_probe - probe children for ACPI FW * @hostdev: LPC host device pointer @@ -555,8 +566,7 @@ static int hisi_lpc_acpi_probe(struct device *hostdev) return 0; fail: - device_for_each_child(hostdev, NULL, - hisi_lpc_acpi_remove_subdev); + hisi_lpc_acpi_remove(hostdev); return ret; } @@ -569,6 +579,10 @@ static int hisi_lpc_acpi_probe(struct device *dev) { return -ENODEV; } + +static void hisi_lpc_acpi_remove(struct device *hostdev) +{ +} #endif // CONFIG_ACPI /* @@ -626,6 +640,8 @@ static int hisi_lpc_probe(struct platform_device *pdev) return ret; } + dev_set_drvdata(dev, lpcdev); + io_end = lpcdev->io_host->io_start + lpcdev->io_host->size; dev_info(dev, "registered range [%pa - %pa]\n", &lpcdev->io_host->io_start, &io_end); @@ -633,6 +649,23 @@ static int hisi_lpc_probe(struct platform_device *pdev) return ret; } +static int hisi_lpc_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct acpi_device *acpi_device = ACPI_COMPANION(dev); + struct hisi_lpc_dev *lpcdev = dev_get_drvdata(dev); + struct logic_pio_hwaddr *range = lpcdev->io_host; + + if (acpi_device) + hisi_lpc_acpi_remove(dev); + else + of_platform_depopulate(dev); + + logic_pio_unregister_range(range); + + return 0; +} + static const struct of_device_id hisi_lpc_of_match[] = { { .compatible = "hisilicon,hip06-lpc", }, { .compatible = "hisilicon,hip07-lpc", }, @@ -646,5 +679,6 @@ static struct platform_driver hisi_lpc_driver = { .acpi_match_table = ACPI_PTR(hisi_lpc_acpi_match), }, .probe = hisi_lpc_probe, + .remove = hisi_lpc_remove, }; builtin_platform_driver(hisi_lpc_driver); -- cgit v1.2.3-59-g8ed1b