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/ABI/removed/sysfs-mce | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 Documentation/ABI/removed/sysfs-mce (limited to 'Documentation/ABI/removed/sysfs-mce') diff --git a/Documentation/ABI/removed/sysfs-mce b/Documentation/ABI/removed/sysfs-mce new file mode 100644 index 000000000..ef5dd2a80 --- /dev/null +++ b/Documentation/ABI/removed/sysfs-mce @@ -0,0 +1,37 @@ +What: /sys/devices/system/machinecheck/machinecheckX/tolerant +Contact: Borislav Petkov +Date: Dec, 2021 +Description: + Unused and obsolete after the advent of recoverable machine + checks (see last sentence below) and those are present since + 2010 (Nehalem). + + Original description: + + The entries appear for each CPU, but they are truly shared + between all CPUs. + + Tolerance level. When a machine check exception occurs for a + non corrected machine check the kernel can take different + actions. + + Since machine check exceptions can happen any time it is + sometimes risky for the kernel to kill a process because it + defies normal kernel locking rules. The tolerance level + configures how hard the kernel tries to recover even at some + risk of deadlock. Higher tolerant values trade potentially + better uptime with the risk of a crash or even corruption + (for tolerant >= 3). + + == =========================================================== + 0 always panic on uncorrected errors, log corrected errors + 1 panic or SIGBUS on uncorrected errors, log corrected errors + 2 SIGBUS or log uncorrected errors, log corrected errors + 3 never panic or SIGBUS, log all errors (for testing only) + == =========================================================== + + Default: 1 + + Note this only makes a difference if the CPU allows recovery + from a machine check exception. Current x86 CPUs generally + do not. -- cgit v1.3.1