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/md/dm-stats.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 drivers/md/dm-stats.h (limited to 'drivers/md/dm-stats.h') diff --git a/drivers/md/dm-stats.h b/drivers/md/dm-stats.h new file mode 100644 index 000000000..c6728c8b4 --- /dev/null +++ b/drivers/md/dm-stats.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef DM_STATS_H +#define DM_STATS_H + +#include +#include +#include + +int dm_statistics_init(void); +void dm_statistics_exit(void); + +struct dm_stats { + struct mutex mutex; + struct list_head list; /* list of struct dm_stat */ + struct dm_stats_last_position __percpu *last; + bool precise_timestamps; +}; + +struct dm_stats_aux { + bool merged; + unsigned long long duration_ns; +}; + +int dm_stats_init(struct dm_stats *st); +void dm_stats_cleanup(struct dm_stats *st); + +struct mapped_device; + +int dm_stats_message(struct mapped_device *md, unsigned int argc, char **argv, + char *result, unsigned int maxlen); + +void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw, + sector_t bi_sector, unsigned int bi_sectors, bool end, + unsigned long start_time, + struct dm_stats_aux *aux); + +static inline bool dm_stats_used(struct dm_stats *st) +{ + return !list_empty(&st->list); +} + +static inline void dm_stats_record_start(struct dm_stats *stats, struct dm_stats_aux *aux) +{ + if (unlikely(stats->precise_timestamps)) + aux->duration_ns = ktime_to_ns(ktime_get()); +} + +#endif -- cgit v1.3.1