From f08252469ef5b10863424e502bb1ed049d18390c Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 14 Apr 2020 18:48:45 +0200 Subject: docs: drivers: fix some warnings at base/platform.c when building docs Currrently, two warnings are generated when building docs: ./drivers/base/platform.c:136: WARNING: Unexpected indentation. ./drivers/base/platform.c:214: WARNING: Unexpected indentation. As examples are code blocks, they should use "::" markup. However, Example:: Is currently interpreted as a new section. While we could fix kernel-doc to accept such new syntax, it is easier to just replace it with: For Example:: Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/564273815a76136fb5e453969b1012a786d99e28.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet --- drivers/base/platform.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5255550b7c34..a07e28eab7d7 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -147,7 +147,8 @@ EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname); * request_irq() APIs. This is the same as platform_get_irq(), except that it * does not print an error message if an IRQ can not be obtained. * - * Example: + * For example:: + * * int irq = platform_get_irq_optional(pdev, 0); * if (irq < 0) * return irq; @@ -226,7 +227,8 @@ EXPORT_SYMBOL_GPL(platform_get_irq_optional); * IRQ fails. Device drivers should check the return value for errors so as to * not pass a negative integer value to the request_irq() APIs. * - * Example: + * For example:: + * * int irq = platform_get_irq(pdev, 0); * if (irq < 0) * return irq; -- cgit From 45bb08de65b418959313593f527c619e102c2d57 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 2 Apr 2020 12:13:41 +0100 Subject: driver core: platform: remove redundant assignment to variable ret The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20200402111341.511801-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5255550b7c34..2e454c18b3a9 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -668,7 +668,7 @@ EXPORT_SYMBOL_GPL(platform_device_unregister); struct platform_device *platform_device_register_full( const struct platform_device_info *pdevinfo) { - int ret = -ENOMEM; + int ret; struct platform_device *pdev; pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id); -- cgit From 9495b7e92f716ab2bd6814fab5e97ab4a39adfdd Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 22 Apr 2020 12:09:54 +0200 Subject: driver core: platform: Initialize dma_parms for platform devices It's currently the platform driver's responsibility to initialize the pointer, dma_parms, for its corresponding struct device. The benefit with this approach allows us to avoid the initialization and to not waste memory for the struct device_dma_parameters, as this can be decided on a case by case basis. However, it has turned out that this approach is not very practical. Not only does it lead to open coding, but also to real errors. In principle callers of dma_set_max_seg_size() doesn't check the error code, but just assumes it succeeds. For these reasons, let's do the initialization from the common platform bus at the device registration point. This also follows the way the PCI devices are being managed, see pci_device_add(). Suggested-by: Christoph Hellwig Cc: Tested-by: Haibo Chen Reviewed-by: Arnd Bergmann Signed-off-by: Ulf Hansson Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20200422100954.31211-1-ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 2 ++ include/linux/platform_device.h | 1 + 2 files changed, 3 insertions(+) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5255550b7c34..b27d0f6c18c9 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -380,6 +380,8 @@ struct platform_object { */ static void setup_pdev_dma_masks(struct platform_device *pdev) { + pdev->dev.dma_parms = &pdev->dma_parms; + if (!pdev->dev.coherent_dma_mask) pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); if (!pdev->dev.dma_mask) { diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index bdc35753ef7c..77a2aada106d 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -25,6 +25,7 @@ struct platform_device { bool id_auto; struct device dev; u64 platform_dma_mask; + struct device_dma_parameters dma_parms; u32 num_resources; struct resource *resource; -- cgit From 388bcc6ecc609fca1b4920de7dc3806c98ec535e Mon Sep 17 00:00:00 2001 From: Kuppuswamy Sathyanarayanan Date: Wed, 8 Apr 2020 14:40:03 -0700 Subject: drivers: base: Fix NULL pointer exception in __platform_driver_probe() if a driver developer is foolish If platform bus driver registration is failed then, accessing platform bus spin lock (&drv->driver.bus->p->klist_drivers.k_lock) in __platform_driver_probe() without verifying the return value __platform_driver_register() can lead to NULL pointer exception. So check the return value before attempting the spin lock. One such example is below: For a custom usecase, I have intentionally failed the platform bus registration and I expected all the platform device/driver registrations to fail gracefully. But I came across this panic issue. [ 1.331067] BUG: kernel NULL pointer dereference, address: 00000000000000c8 [ 1.331118] #PF: supervisor write access in kernel mode [ 1.331163] #PF: error_code(0x0002) - not-present page [ 1.331208] PGD 0 P4D 0 [ 1.331233] Oops: 0002 [#1] PREEMPT SMP [ 1.331268] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G W 5.6.0-00049-g670d35fb0144 #165 [ 1.331341] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 1.331406] RIP: 0010:_raw_spin_lock+0x15/0x30 [ 1.331588] RSP: 0000:ffffc9000001be70 EFLAGS: 00010246 [ 1.331632] RAX: 0000000000000000 RBX: 00000000000000c8 RCX: 0000000000000001 [ 1.331696] RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000000 [ 1.331754] RBP: 00000000ffffffed R08: 0000000000000501 R09: 0000000000000001 [ 1.331817] R10: ffff88817abcc520 R11: 0000000000000670 R12: 00000000ffffffed [ 1.331881] R13: ffffffff82dbc268 R14: ffffffff832f070a R15: 0000000000000000 [ 1.331945] FS: 0000000000000000(0000) GS:ffff88817bd80000(0000) knlGS:0000000000000000 [ 1.332008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.332062] CR2: 00000000000000c8 CR3: 000000000681e001 CR4: 00000000003606e0 [ 1.332126] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1.332189] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1.332252] Call Trace: [ 1.332281] __platform_driver_probe+0x92/0xee [ 1.332323] ? rtc_dev_init+0x2b/0x2b [ 1.332358] cmos_init+0x37/0x67 [ 1.332396] do_one_initcall+0x7d/0x168 [ 1.332428] kernel_init_freeable+0x16c/0x1c9 [ 1.332473] ? rest_init+0xc0/0xc0 [ 1.332508] kernel_init+0x5/0x100 [ 1.332543] ret_from_fork+0x1f/0x30 [ 1.332579] CR2: 00000000000000c8 [ 1.332616] ---[ end trace 3bd87f12e9010b87 ]--- [ 1.333549] note: swapper/0[1] exited with preempt_count 1 [ 1.333592] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [ 1.333736] Kernel Offset: disabled Note, this can only be triggered if a driver errors out from this call, which should never happen. If it does, the driver needs to be fixed. Signed-off-by: Kuppuswamy Sathyanarayanan Link: https://lore.kernel.org/r/20200408214003.3356-1-sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 2e454c18b3a9..2c1812d75762 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -849,6 +849,8 @@ int __init_or_module __platform_driver_probe(struct platform_driver *drv, /* temporary section violation during probe() */ drv->probe = probe; retval = code = __platform_driver_register(drv, module); + if (retval) + return retval; /* * Fixup that section violation, being paranoid about code scanning -- cgit From a85a6c86c25be2d2a5f9c31491f612ce0edc7869 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Mon, 16 Mar 2020 16:43:38 -0500 Subject: driver core: platform: Clarify that IRQ 0 is invalid These interfaces return a negative error number or an IRQ: platform_get_irq() platform_get_irq_optional() platform_get_irq_byname() platform_get_irq_byname_optional() The function comments suggest checking for error like this: irq = platform_get_irq(...); if (irq < 0) return irq; which is what most callers (~900 of 1400) do, so it's implicit that IRQ 0 is invalid. But some callers check for "irq <= 0", and it's not obvious from the source that we never return an IRQ 0. Make this more explicit by updating the comments to say that an IRQ number is always non-zero and adding a WARN() if we ever do return zero. If we do return IRQ 0, it likely indicates a bug in the arch-specific parts of platform_get_irq(). Relevant prior discussion at [1, 2]. [1] https://lore.kernel.org/r/Pine.LNX.4.64.0701250940220.25027@woody.linux-foundation.org/ [2] https://lore.kernel.org/r/Pine.LNX.4.64.0701252029570.25027@woody.linux-foundation.org/ Signed-off-by: Bjorn Helgaas Acked-by: Greg Kroah-Hartman Acked-by: Linus Walleij --- drivers/base/platform.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5255550b7c34..084cf1d23d3f 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -152,23 +152,24 @@ EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname); * if (irq < 0) * return irq; * - * Return: IRQ number on success, negative error number on failure. + * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) { + int ret; #ifdef CONFIG_SPARC /* sparc does not have irqs represented as IORESOURCE_IRQ resources */ if (!dev || num >= dev->archdata.num_irqs) return -ENXIO; - return dev->archdata.irqs[num]; + ret = dev->archdata.irqs[num]; + goto out; #else struct resource *r; - int ret; if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) { ret = of_irq_get(dev->dev.of_node, num); if (ret > 0 || ret == -EPROBE_DEFER) - return ret; + goto out; } r = platform_get_resource(dev, IORESOURCE_IRQ, num); @@ -176,7 +177,7 @@ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) if (r && r->flags & IORESOURCE_DISABLED) { ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r); if (ret) - return ret; + goto out; } } @@ -190,13 +191,17 @@ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) struct irq_data *irqd; irqd = irq_get_irq_data(r->start); - if (!irqd) - return -ENXIO; + if (!irqd) { + ret = -ENXIO; + goto out; + } irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); } - if (r) - return r->start; + if (r) { + ret = r->start; + goto out; + } /* * For the index 0 interrupt, allow falling back to GpioInt @@ -209,11 +214,14 @@ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num); /* Our callers expect -ENXIO for missing IRQs. */ if (ret >= 0 || ret == -EPROBE_DEFER) - return ret; + goto out; } - return -ENXIO; + ret = -ENXIO; #endif +out: + WARN(ret == 0, "0 is an invalid IRQ number\n"); + return ret; } EXPORT_SYMBOL_GPL(platform_get_irq_optional); @@ -231,7 +239,7 @@ EXPORT_SYMBOL_GPL(platform_get_irq_optional); * if (irq < 0) * return irq; * - * Return: IRQ number on success, negative error number on failure. + * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq(struct platform_device *dev, unsigned int num) { @@ -303,8 +311,10 @@ static int __platform_get_irq_byname(struct platform_device *dev, } r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name); - if (r) + if (r) { + WARN(r->start == 0, "0 is an invalid IRQ number\n"); return r->start; + } return -ENXIO; } @@ -316,7 +326,7 @@ static int __platform_get_irq_byname(struct platform_device *dev, * * Get an IRQ like platform_get_irq(), but then by name rather then by index. * - * Return: IRQ number on success, negative error number on failure. + * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq_byname(struct platform_device *dev, const char *name) { @@ -338,7 +348,7 @@ EXPORT_SYMBOL_GPL(platform_get_irq_byname); * Get an optional IRQ by name like platform_get_irq_byname(). Except that it * does not print an error message if an IRQ can not be obtained. * - * Return: IRQ number on success, negative error number on failure. + * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq_byname_optional(struct platform_device *dev, const char *name) -- cgit From c82c83c330654c5639960ebc3dabbae53c43f79e Mon Sep 17 00:00:00 2001 From: Tang Bin Date: Wed, 20 May 2020 22:12:02 +0800 Subject: driver core: platform: Fix spelling errors in platform.c There is a word spelling mistake of 'Unegisters', thus it should be fixed. Signed-off-by: Tang Bin Link: https://lore.kernel.org/r/20200520141202.19568-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 4ed3dc38f45c..fe08ef8ffd5c 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -977,7 +977,7 @@ EXPORT_SYMBOL_GPL(__platform_register_drivers); * @drivers: an array of drivers to unregister * @count: the number of drivers to unregister * - * Unegisters platform drivers specified by an array. This is typically used + * Unregisters platform drivers specified by an array. This is typically used * to complement an earlier call to platform_register_drivers(). Drivers are * unregistered in the reverse order in which they were registered. */ -- cgit