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Qian Cai c9790fb5df powerpc/powernv/pci: fix a RCU-list lock
It is unsafe to traverse tbl->it_group_list without the RCU read lock.

 WARNING: suspicious RCU usage
 5.7.0-rc4-next-20200508 #1 Not tainted
 -----------------------------
 arch/powerpc/platforms/powernv/pci-ioda-tce.c:355 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 3 locks held by qemu-kvm/4305:
  #0: c000000bc3fe6988 (&container->group_lock){++++}-{3:3}, at: vfio_fops_unl_ioctl+0x108/0x410 [vfio]
  #1: c00800000fcc7400 (&vfio.iommu_drivers_lock){+.+.}-{3:3}, at: vfio_fops_unl_ioctl+0x148/0x410 [vfio]
  #2: c000000bc3fe4d68 (&container->lock){+.+.}-{3:3}, at: tce_iommu_attach_group+0x3c/0x4f0 [vfio_iommu_spapr_tce]

 stack backtrace:
 CPU: 4 PID: 4305 Comm: qemu-kvm Not tainted 5.7.0-rc4-next-20200508 #1
 Call Trace:
 [c0000010f29afa60] [c0000000007154c8] dump_stack+0xfc/0x174 (unreliable)
 [c0000010f29afab0] [c0000000001d8ff0] lockdep_rcu_suspicious+0x140/0x164
 [c0000010f29afb30] [c0000000000dae2c] pnv_pci_unlink_table_and_group+0x11c/0x200
 [c0000010f29afb70] [c0000000000d4a34] pnv_pci_ioda2_unset_window+0xc4/0x190
 [c0000010f29afbf0] [c0000000000d4b4c] pnv_ioda2_take_ownership+0x4c/0xd0
 [c0000010f29afc30] [c00800000fd60ee0] tce_iommu_attach_group+0x2c8/0x4f0 [vfio_iommu_spapr_tce]
 [c0000010f29afcd0] [c00800000fcc11a0] vfio_fops_unl_ioctl+0x238/0x410 [vfio]
 [c0000010f29afd50] [c0000000005430a8] ksys_ioctl+0xd8/0x130
 [c0000010f29afda0] [c000000000543128] sys_ioctl+0x28/0x40
 [c0000010f29afdc0] [c000000000038af4] system_call_exception+0x114/0x1e0
 [c0000010f29afe20] [c00000000000c8f0] system_call_common+0xf0/0x278

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200510051347.1906-1-cai@lca.pw
2021-01-31 22:35:49 +11:00
arch powerpc/powernv/pci: fix a RCU-list lock 2021-01-31 22:35:49 +11:00
block SCSI fixes on 20210101 2021-01-01 12:58:07 -08:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: aegis128 - avoid spurious references crypto_aegis128_update_simd 2020-12-04 18:16:53 +11:00
Documentation A small set of late-arriving, small documentation fixes. 2020-12-24 14:20:33 -08:00
drivers ocxl: use DEFINE_MUTEX() for mutex lock 2021-01-30 11:39:21 +11:00
fs block-5.11-2021-01-01 2021-01-01 12:49:09 -08:00
include SCSI fixes on 20210101 2021-01-01 12:58:07 -08:00
init kasan, arm64: only use kasan_depth for software modes 2020-12-22 12:55:07 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
kernel io_uring-5.11-2021-01-01 2021-01-01 12:29:49 -08:00
lib zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c 2020-12-29 15:36:49 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm mm: slub: call account_slab_page() after slab page initialization 2020-12-29 15:36:49 -08:00
net libceph: align session_key and con_secret to 16 bytes 2020-12-28 20:34:33 +01:00
samples ARM: SoC drivers for v5.11 2020-12-16 16:38:41 -08:00
scripts depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-01 12:26:39 -08:00
security Provide a fix for the incorrect handling of privilege 2020-12-24 14:08:43 -08:00
sound sound fixes for 5.11-rc1 2020-12-23 15:11:08 -08:00
tools selftests/powerpc: Add VF recovery tests 2021-01-31 22:35:47 +11:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt ARM: 2020-12-20 10:44:05 -08:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap RDMA 5.11 pull request 2020-12-16 13:42:26 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-11 22:29:38 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge branches 'pm-cpufreq' and 'pm-cpuidle' 2021-01-02 10:16:32 +01:00
Makefile Linux 5.11-rc2 2021-01-03 15:55:30 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.