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Filename Latest commit message Latest commit date
Michael Ellerman ccb0a42d3f powerpc/pci: Fix get_phb_number() locking
commit 8d48562a2729742f767b0fdd994d6b2a56a49c63 upstream.

The recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP
warning on some systems:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper
  preempt_count: 1, expected: 0
  RCU nest depth: 0, expected: 0
  1 lock held by swapper/1:
   #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220
  Preemption disabled at:
  [<00000000>] 0x0
  CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1
  Call Trace:
  [d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable)
  [d101dcb0] [c0093b70] __might_resched+0x258/0x2a8
  [d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec
  [d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4
  [d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220
  [d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784
  [d101de50] [c140852c] discover_phbs+0x30/0x4c
  [d101de60] [c0007fd4] do_one_initcall+0x94/0x344
  [d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c
  [d101df10] [c00086e0] kernel_init+0x34/0x160
  [d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64

This is because pcibios_alloc_controller() holds hose_spinlock but
of_alias_get_id() takes of_mutex which can sleep.

The hose_spinlock protects the phb_bitmap, and also the hose_list, but
it doesn't need to be held while get_phb_number() calls the OF routines,
because those are only looking up information in the device tree.

So fix it by having get_phb_number() take the hose_spinlock itself, only
where required, and then dropping the lock before returning.
pcibios_alloc_controller() then needs to take the lock again before the
list_add() but that's safe, the order of the list is not important.

Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220815065550.1303620-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:18:29 +02:00
arch powerpc/pci: Fix get_phb_number() locking 2022-08-25 11:18:29 +02:00
block blk-mq: don't create hctx debugfs dir until q->debugfs_dir is created 2022-08-25 11:17:36 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:11:22 +02:00
crypto crypto: drbg - make reseeding from get_random_bytes() synchronous 2022-06-22 14:11:18 +02:00
Documentation dt-bindings: arm: qcom: fix MSM8916 MTP compatibles 2022-08-25 11:18:25 +02:00
drivers clk: rockchip: add sclk_mac_lbtest to rk3188_critical_clocks 2022-08-25 11:18:28 +02:00
fs NFSv4/pnfs: Fix a use-after-free bug in open 2022-08-25 11:18:22 +02:00
include KVM: Add infrastructure and macro to mark VM as bugged 2022-08-25 11:18:16 +02:00
init random: handle latent entropy and command line from random_init() 2022-06-22 14:11:17 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-14 18:11:41 +02:00
kernel tracing: Have filter accept "common_cpu" to be consistent 2022-08-25 11:18:19 +02:00
lib locking/refcount: Consolidate implementations of refcount_t 2022-07-29 17:14:17 +02:00
LICENSES
mm mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region 2022-08-25 11:17:58 +02:00
net netfilter: nf_tables: really skip inactive sets when allocating name 2022-08-25 11:18:29 +02:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts scripts/faddr2line: Fix vmlinux detection on arm64 2022-08-25 11:18:08 +02:00
security apparmor: Fix memleak in aa_simple_write_to_buffer() 2022-08-25 11:18:21 +02:00
sound ALSA: info: Fix llseek return value when using callback 2022-08-25 11:18:18 +02:00
tools tools build: Switch to new openssl API for test-libcrypto 2022-08-25 11:18:25 +02:00
usr
virt KVM: Add infrastructure and macro to mark VM as bugged 2022-08-25 11:18:16 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS MAINTAINERS: co-maintain random.c 2022-06-22 14:11:05 +02:00
Makefile Makefile: link with -z noexecstack --no-warn-rwx-segments 2022-08-25 11:17:17 +02:00
README

Linux kernel
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There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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