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 --- drivers/ras/debugfs.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 drivers/ras/debugfs.c (limited to 'drivers/ras/debugfs.c') diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c new file mode 100644 index 000000000..42afd3de6 --- /dev/null +++ b/drivers/ras/debugfs.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include "debugfs.h" + +static struct dentry *ras_debugfs_dir; + +static atomic_t trace_count = ATOMIC_INIT(0); + +struct dentry *ras_get_debugfs_root(void) +{ + return ras_debugfs_dir; +} +EXPORT_SYMBOL_GPL(ras_get_debugfs_root); + +int ras_userspace_consumers(void) +{ + return atomic_read(&trace_count); +} +EXPORT_SYMBOL_GPL(ras_userspace_consumers); + +static int trace_show(struct seq_file *m, void *v) +{ + return 0; +} + +static int trace_open(struct inode *inode, struct file *file) +{ + atomic_inc(&trace_count); + return single_open(file, trace_show, NULL); +} + +static int trace_release(struct inode *inode, struct file *file) +{ + atomic_dec(&trace_count); + return single_release(inode, file); +} + +static const struct file_operations trace_fops = { + .open = trace_open, + .read = seq_read, + .llseek = seq_lseek, + .release = trace_release, +}; + +int __init ras_add_daemon_trace(void) +{ + struct dentry *fentry; + + if (!ras_debugfs_dir) + return -ENOENT; + + fentry = debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir, + NULL, &trace_fops); + if (IS_ERR(fentry)) + return -ENODEV; + + return 0; + +} + +void __init ras_debugfs_init(void) +{ + ras_debugfs_dir = debugfs_create_dir("ras", NULL); +} -- cgit v1.3.1