From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- Documentation/block/error-injection.rst | 59 +++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 Documentation/block/error-injection.rst (limited to 'Documentation/block/error-injection.rst') diff --git a/Documentation/block/error-injection.rst b/Documentation/block/error-injection.rst new file mode 100644 index 000000000..81f31af82 --- /dev/null +++ b/Documentation/block/error-injection.rst @@ -0,0 +1,59 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================ +Configurable Error Injection +============================ + +Overview +-------- + +Configurable error injection allows injecting specific block layer status codes +for sector ranges of a block device. Errors can be injected unconditionally, or +with a given probability. + +To use configurable error injection, CONFIG_BLK_ERROR_INJECTION must be enabled. + +The only interface is the error_injection debugfs file, which is created for +each registered gendisk. Writes to this file are used to create or delete rules +and reads return a list of the current error injection sites. + +Options +------- + +The following options specify the operations: + +=================== ======================================================= +add add a new rule +removeall remove all existing rules +=================== ======================================================= + +The following options specify the details of the rule for the add operation: + +=================== ======================================================= +op= block layer operation this rule applies to. This uses + the XYZ for each REQ_OP_XYZ operation, e.g. READ, WRITE + or DISCARD. Mandatory. +status= Status to return. This uses XYZ for each BLK_STS_XYZ + code, e.g. IOERR or MEDIUM. Mandatory. +start= First block layer sector the rule applies to. + Optional, defaults to 0. +nr_sectors= Number of sectors this rule applies. + Optional, defaults to the remainder of the device. +chance= Only return a failure with a likelihood of 1/chance. + Optional, defaults to 1 (always). +=================== ======================================================= + +Example +------- + +Return BLK_STS_IOERR for one in 10 reads of sector 0 of /dev/nvme0n1: + + $ echo 'add,op=READ,start=0,status=IOERR,chance=10' > /sys/kernel/debug/block/nvme0n1/error_injection + +Return BLK_STS_MEDIUM for every write to /dev/nvme0n1: + + $ echo 'add,op=WRITE,start=0,status=MEDIUM' > /sys/kernel/debug/block/nvme0n1/error_injection + +Remove all rules for /dev/nvme0n1: + + $ echo 'removeall' > /sys/kernel/debug/block/nvme0n1/error_injection -- cgit v1.3.1