From 7e89efc6e9e402839643cb297bab14055c547f07 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 2 May 2024 09:57:31 -0700 Subject: PCI: Lock upstream bridge for pci_reset_function() Fix a long-standing locking gap for missing pci_cfg_access_lock() while manipulating bridge reset registers and configuration during pci_reset_bus_function(). If there is an upstream bridge, lock it before locking the device itself. pci_dev_lock() calls pci_cfg_access_lock(), which blocks the writing of PCI config space by user space. Add lockdep assertion via pci_dev->cfg_access_lock to verify pci_dev->block_cfg_access is set. Co-developed-by: Dan Williams Link: https://lore.kernel.org/r/20240502165851.1948523-3-dave.jiang@intel.com Signed-off-by: Dan Williams Signed-off-by: Dave Jiang [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas --- include/linux/lockdep.h | 5 +++++ include/linux/pci.h | 2 ++ 2 files changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 08b0d1d9d78b..5e51b0de4c4b 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -297,6 +297,9 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); .wait_type_inner = _wait_type, \ .lock_type = LD_LOCK_WAIT_OVERRIDE, } +#define lock_map_assert_held(l) \ + lockdep_assert(lock_is_held(l) != LOCK_STATE_NOT_HELD) + #else /* !CONFIG_LOCKDEP */ static inline void lockdep_init_task(struct task_struct *task) @@ -388,6 +391,8 @@ extern int lockdep_is_held(const void *); #define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type) \ struct lockdep_map __maybe_unused _name = {} +#define lock_map_assert_held(l) do { (void)(l); } while (0) + #endif /* !LOCKDEP */ #ifdef CONFIG_PROVE_LOCKING diff --git a/include/linux/pci.h b/include/linux/pci.h index 16493426a04f..e4e7b175af54 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -413,6 +413,8 @@ struct pci_dev { struct resource driver_exclusive_resource; /* driver exclusive resource ranges */ bool match_driver; /* Skip attaching driver */ + struct lock_class_key cfg_access_key; + struct lockdep_map cfg_access_lock; unsigned int transparent:1; /* Subtractive decode bridge */ unsigned int io_window:1; /* Bridge has I/O window */ -- cgit v1.2.3