linux-dev/drivers/misc/ocxl/file.c, branch linus/master

misc: ocxl: fix possible double free in ocxl_file_register_afu

2022-04-21T06:42:43Z

info_release() will be called in device_unregister() when info->dev's reference count is 0. So there is no need to call ocxl_afu_put() and kfree() again. Fix this by adding free_minor() and return to err_unregister error path. Fixes: 75ca758adbaf ("ocxl: Create a clear delineation between ocxl backend & frontend") Signed-off-by: Hangyu Hua Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220418085758.38145-1-hbh25y@gmail.com

ocxl: remove redundant rc variable

2021-12-20T01:15:33Z

Return value from ocxl_context_attach() directly instead of taking this in another redundant variable. Reported-by: Zeal Robot Signed-off-by: Minghao Chi Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211215060438.441918-1-chi.minghao@zte.com.cn

ocxl: use DEFINE_MUTEX() for mutex lock

2021-01-30T00:39:21Z

mutex lock can be initialized automatically with DEFINE_MUTEX() rather than explicitly calling mutex_init(). Signed-off-by: Zheng Yongjun Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201224132446.31286-1-zhengyongjun3@huawei.com

ocxl: Fix concurrent AFU open and device removal

2019-12-10T09:34:23Z

If an ocxl device is unbound through sysfs at the same time its AFU is being opened by a user process, the open code may dereference freed stuctures, which can lead to kernel oops messages. You'd have to hit a tiny time window, but it's possible. It's fairly easy to test by making the time window bigger artificially. Fix it with a combination of 2 changes: - when an AFU device is found in the IDR by looking for the device minor number, we should hold a reference on the device until after the context is allocated. A reference on the AFU structure is kept when the context is allocated, so we can release the reference on the device after the context allocation. - with the fix above, there's still another even tinier window, between the time the AFU device is found in the IDR and the reference on the device is taken. We can fix this one by removing the IDR entry earlier, when the device setup is removed, instead of waiting for the 'release' device callback. With proper locking around the IDR. Fixes: 75ca758adbaf ("ocxl: Create a clear delineation between ocxl backend & frontend") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Frederic Barrat Reviewed-by: Greg Kurz Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190624144148.32022-1-fbarrat@linux.ibm.com

ocxl: Fix return value check in afu_ioctl()

2019-05-06T10:21:56Z

In case of error, the function eventfd_ctx_fdget() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). This issue was detected by using the Coccinelle software. Fixes: 060146614643 ("ocxl: move event_fd handling to frontend") Signed-off-by: Wei Yongjun Acked-by: Alastair D'Silva Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

ocxl: move event_fd handling to frontend

2019-05-02T16:55:02Z

Event_fd is only used in the driver frontend, so it does not need to exist in the backend code. Relocate it to the frontend and provide an opaque mechanism for consumers instead. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: afu_irq only deals with IRQ IDs, not offsets

2019-05-02T16:55:02Z

The use of offsets is required only in the frontend, so alter the IRQ API to only work with IRQ IDs in the backend. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: Allow external drivers to use OpenCAPI contexts

2019-05-02T16:55:02Z

Most OpenCAPI operations require a valid context, so exposing these functions to external drivers is necessary. Signed-off-by: Alastair D'Silva Reviewed-by: Greg Kurz Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: Create a clear delineation between ocxl backend & frontend

2019-05-02T16:55:01Z

The OCXL driver contains both frontend code for interacting with userspace, as well as backend code for interacting with the hardware. This patch separates the backend code from the frontend so that it can be used by other device drivers that communicate via OpenCAPI. Relocate dev, cdev & sysfs files to the frontend code to allow external drivers to maintain their own devices. Reference counting on the device in the backend is replaced with kref counting. Move file & sysfs layer initialisation from core.c (backend) to pci.c (frontend). Create an ocxl_function oriented interface for initing devices & enumerating AFUs. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: Rename struct link to ocxl_link

2019-05-02T16:55:00Z

The term 'link' is ambiguous (especially when the struct is used for a list), so rename it for clarity. Signed-off-by: Alastair D'Silva Reviewed-by: Greg Kurz Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman