Hello,
This series moves all drivers to a dynamic dma-buf locking specification.
From now on all dma-buf importers are made responsible for holding
dma-buf's reservation lock around all operations performed over dma-bufs
in accordance to the locking specification. This allows us to utilize
reservation lock more broadly around kernel without fearing of a potential
deadlocks.
This patchset passes all i915 selftests. It was also tested using VirtIO,
Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases
of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate),
which covers majority of kernel drivers since rest of the drivers share
same or similar code paths.
Changelog:
v7: - Rebased on top of recent drm-misc-next.
- Added ack from Jason Gunthorpe to the RDMA patch.
- Added iosys_map_clear() to dma_buf_vmap_unlocked(), making it fully
consistent with dma_buf_vmap().
v6: - Added r-b from Michael Ruhl to the i915 patch.
- Added acks from Sumit Semwal and updated commit message of the
"Move dma_buf_vmap() to dynamic locking specification" patch like
was suggested by Sumit.
- Added "!dmabuf" check to dma_buf_vmap_unlocked() to match the locked
variant of the function, for consistency.
v5: - Added acks and r-bs that were given to v4.
- Changed i915 preparation patch like was suggested by Michael Ruhl.
The scope of reservation locking is smaller now.
v4: - Added dma_buf_mmap() to the "locking convention" documentation,
which was missed by accident in v3.
- Added acks from Christian König, Tomasz Figa and Hans Verkuil that
they gave to couple v3 patches.
- Dropped the "_unlocked" postfix from function names that don't have
the locked variant, as was requested by Christian König.
- Factored out the per-driver preparations into separate patches
to ease reviewing of the changes, which is now doable without the
global dma-buf functions renaming.
- Factored out the dynamic locking convention enforcements into separate
patches which add the final dma_resv_assert_held(dmabuf->resv) to the
dma-buf API functions.
v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
into aseparate patches, like was suggested by Christian König.
- Corrected and factored out dma-buf locking documentation into
a separate patch, like was suggested by Christian König.
- Intel driver dropped the reservation locking fews days ago from
its BO-release code path, but we need that locking for the imported
GEMs because in the end that code path unmaps the imported GEM.
So I added back the locking needed by the imported GEMs, updating
the "dma-buf attachment locking specification" patch appropriately.
- Tested Nouveau+Intel dma-buf import/export combo.
- Tested udmabuf import to i915/Nouveau/AMDGPU.
- Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed
to switch to locked dma-buf vmapping in the drm/gem: Take reservation
lock for vmap/vunmap operations" patch. In a result invalidated the
Christian's r-b that he gave to v2.
- Added locked dma-buf vmap/vunmap functions that are needed for fixing
vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
I actually had this change stashed for the drm-shmem shrinker patchset,
but then realized that it's already needed by the dma-buf patches.
Also improved my tests to better cover these code paths.
v2: - Changed locking specification to avoid problems with a cross-driver
ww locking, like was suggested by Christian König. Now the attach/detach
callbacks are invoked without the held lock and exporter should take the
lock.
- Added "locking convention" documentation that explains which dma-buf
functions and callbacks are locked/unlocked for importers and exporters,
which was requested by Christian König.
- Added ack from Tomasz Figa to the V4L patches that he gave to v1.
Dmitry Osipenko (21):
dma-buf: Add unlocked variant of vmapping functions
dma-buf: Add unlocked variant of attachment-mapping functions
drm/gem: Take reservation lock for vmap/vunmap operations
drm/prime: Prepare to dynamic dma-buf locking specification
drm/armada: Prepare to dynamic dma-buf locking specification
drm/i915: Prepare to dynamic dma-buf locking specification
drm/omapdrm: Prepare to dynamic dma-buf locking specification
drm/tegra: Prepare to dynamic dma-buf locking specification
drm/etnaviv: Prepare to dynamic dma-buf locking specification
RDMA/umem: Prepare to dynamic dma-buf locking specification
misc: fastrpc: Prepare to dynamic dma-buf locking specification
xen/gntdev: Prepare to dynamic dma-buf locking specification
media: videobuf2: Prepare to dynamic dma-buf locking specification
media: tegra-vde: Prepare to dynamic dma-buf locking specification
dma-buf: Move dma_buf_vmap() to dynamic locking specification
dma-buf: Move dma_buf_attach() to dynamic locking specification
dma-buf: Move dma_buf_map_attachment() to dynamic locking
specification
dma-buf: Move dma_buf_mmap() to dynamic locking specification
dma-buf: Document dynamic locking convention
media: videobuf2: Stop using internal dma-buf lock
dma-buf: Remove obsoleted internal lock
Documentation/driver-api/dma-buf.rst | 6 +
drivers/dma-buf/dma-buf.c | 216 +++++++++++++++---
drivers/gpu/drm/armada/armada_gem.c | 8 +-
drivers/gpu/drm/drm_client.c | 4 +-
drivers/gpu/drm/drm_gem.c | 24 ++
drivers/gpu/drm/drm_gem_dma_helper.c | 6 +-
drivers/gpu/drm/drm_gem_framebuffer_helper.c | 6 +-
drivers/gpu/drm/drm_gem_ttm_helper.c | 9 +-
drivers/gpu/drm/drm_prime.c | 6 +-
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_object.c | 14 ++
.../drm/i915/gem/selftests/i915_gem_dmabuf.c | 16 +-
drivers/gpu/drm/lima/lima_sched.c | 4 +-
drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 4 +-
drivers/gpu/drm/panfrost/panfrost_dump.c | 4 +-
drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 6 +-
drivers/gpu/drm/qxl/qxl_object.c | 17 +-
drivers/gpu/drm/qxl/qxl_prime.c | 4 +-
drivers/gpu/drm/tegra/gem.c | 17 +-
drivers/infiniband/core/umem_dmabuf.c | 7 +-
.../common/videobuf2/videobuf2-dma-contig.c | 22 +-
.../media/common/videobuf2/videobuf2-dma-sg.c | 19 +-
.../common/videobuf2/videobuf2-vmalloc.c | 17 +-
.../platform/nvidia/tegra-vde/dmabuf-cache.c | 6 +-
drivers/misc/fastrpc.c | 6 +-
drivers/xen/gntdev-dmabuf.c | 8 +-
include/drm/drm_gem.h | 3 +
include/linux/dma-buf.h | 17 +-
29 files changed, 325 insertions(+), 155 deletions(-)
--
2.37.3
Back in April, I posted an RFC patch set to help mitigate a common issue
where a timer gets armed just before it is freed, and when the timer
goes off, it crashes in the timer code without any evidence of who the
culprit was. I got side tracked and never finished up on that patch set.
Since this type of crash is still our #1 crash we are seeing in the field,
it has become a priority again to finish it.
The last version of that patch set is here:
https://lore.kernel.org/all/20221104054053.431922658@goodmis.org/
I'm calling this version 4a as it only has obvious changes were the timer that
is being shutdown is in the same function where it will be freed or released,
as this series should be "safe" for adding. I'll be calling the other patches
4b for the next merge window.
Patch 1 fixes an issue with sunrpc/xprt where it incorrectly uses
del_singleshot_timer_sync() for something that is not a oneshot timer. As this
will be converted to shutdown, this needs to be fixed first.
Patches 2-4 changes existing timer_shutdown() functions used locally in ARM and
some drivers to better namespace names.
Patch 5 implements the new timer_shutdown() and timer_shutdown_sync() functions
that disable re-arming the timer after they are called.
Patches 6-28 change all the locations where there's a kfree(), kfree_rcu(),
kmem_cache_free() and one call_rcu() call where the RCU function frees the
timer (the workqueue patch) in the same function as the del_timer{,_sync}() is
called on that timer, and there's no extra exit path between the del_timer and
freeing of the timer.
Patches 29-32 add timer_shutdown*() on on-stack timers that are about to be
released at the end of the function.
Patches 33-37 add timer_shutdown*() on module timers in the module exit code.
Patch 38 simply converts an open coded "shutdown" code into timer_shutdown(),
as a way timer_shutdown() disables the timer is by setting that timer function
to NULL.
Linus, I sorted the patches this way to let you see which you would think is
safe to go into this -rc. I honestly believe that they are all safe, but that's
just my own opinion.
This series is here:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
timers-start
Head SHA1: f58b516a65bac76f1bfa00126856d6c6c3d24a40
Steven Rostedt (Google) (38):
SUNRPC/xprt: Use del_timer_sync() instead of del_singleshot_timer_sync()
ARM: spear: Do not use timer namespace for timer_shutdown() function
clocksource/drivers/arm_arch_timer: Do not use timer namespace for timer_shutdown() function
clocksource/drivers/sp804: Do not use timer namespace for timer_shutdown() function
timers: Add timer_shutdown_sync() and timer_shutdown() to be called before freeing timers
timers: sh: Use timer_shutdown_sync() before freeing timer
timers: block: Use timer_shutdown_sync() before freeing timer
timers: ACPI: Use timer_shutdown_sync() before freeing timer
timers: atm: Use timer_shutdown_sync() before freeing timer
timers: Bluetooth: Use timer_shutdown_sync() before freeing timer
timers: drm: Use timer_shutdown_sync() before freeing timer
timers: HID: Use timer_shutdown_sync() before freeing timer
timers: Input: Use timer_shutdown_sync() before freeing timer
timers: mISDN: Use timer_shutdown_sync() before freeing timer
timers: leds: Use timer_shutdown_sync() before freeing timer
timers: media: Use timer_shutdown_sync() before freeing timer
timers: net: Use timer_shutdown_sync() before freeing timer
timers: usb: Use timer_shutdown_sync() before freeing timer
timers: nfc: pn533: Use timer_shutdown_sync() before freeing timer
timers: pcmcia: Use timer_shutdown_sync() before freeing timer
timers: scsi: Use timer_shutdown_sync() and timer_shutdown() before freeing timer
timers: tty: Use timer_shutdown_sync() before freeing timer
timers: ext4: Use timer_shutdown_sync() before freeing timer
timers: fs/nilfs2: Use timer_shutdown_sync() before freeing timer
timers: ALSA: Use timer_shutdown_sync() before freeing timer
timers: jbd2: Use timer_shutdown() before freeing timer
timers: sched/psi: Use timer_shutdown_sync() before freeing timer
timers: workqueue: Use timer_shutdown_sync() before freeing timer
random: use timer_shutdown_sync() for on stack timers
timers: dma-buf: Use timer_shutdown_sync() for on stack timers
timers: drm: Use timer_shutdown_sync() for on stack timers
timers: media: Use timer_shutdown_sync() for on stack timers
timers: s390/cmm: Use timer_shutdown_sync() before a module is released
timers: atm: Use timer_shutdown_sync() before a module is released
timers: hangcheck: Use timer_shutdown_sync() before a module is released
timers: ipmi: Use timer_shutdown_sync() before a module is released
timers: Input: Use timer_shutdown_sync() before a module is released
timers: PM: Use timer_shutdown_sync()
----
.../RCU/Design/Requirements/Requirements.rst | 2 +-
Documentation/core-api/local_ops.rst | 2 +-
Documentation/kernel-hacking/locking.rst | 5 ++
arch/arm/mach-spear/time.c | 8 +--
arch/s390/mm/cmm.c | 4 +-
arch/sh/drivers/push-switch.c | 2 +-
block/blk-iocost.c | 2 +-
block/blk-iolatency.c | 2 +-
block/blk-throttle.c | 2 +-
block/kyber-iosched.c | 2 +-
drivers/acpi/apei/ghes.c | 2 +-
drivers/atm/idt77105.c | 4 +-
drivers/atm/idt77252.c | 4 +-
drivers/atm/iphase.c | 2 +-
drivers/base/power/wakeup.c | 7 +--
drivers/block/drbd/drbd_main.c | 2 +-
drivers/block/loop.c | 2 +-
drivers/block/sunvdc.c | 2 +-
drivers/bluetooth/hci_bcsp.c | 2 +-
drivers/bluetooth/hci_h5.c | 4 +-
drivers/bluetooth/hci_qca.c | 4 +-
drivers/char/hangcheck-timer.c | 4 +-
drivers/char/ipmi/ipmi_msghandler.c | 2 +-
drivers/char/random.c | 2 +-
drivers/clocksource/arm_arch_timer.c | 12 ++--
drivers/clocksource/timer-sp804.c | 6 +-
drivers/dma-buf/st-dma-fence.c | 2 +-
drivers/gpu/drm/gud/gud_pipe.c | 2 +-
drivers/gpu/drm/i915/i915_sw_fence.c | 2 +-
drivers/hid/hid-wiimote-core.c | 2 +-
drivers/input/keyboard/locomokbd.c | 2 +-
drivers/input/keyboard/omap-keypad.c | 2 +-
drivers/input/mouse/alps.c | 2 +-
drivers/input/serio/hil_mlc.c | 2 +-
drivers/isdn/hardware/mISDN/hfcmulti.c | 5 +-
drivers/isdn/mISDN/l1oip_core.c | 4 +-
drivers/isdn/mISDN/timerdev.c | 4 +-
drivers/leds/trigger/ledtrig-pattern.c | 2 +-
drivers/leds/trigger/ledtrig-transient.c | 2 +-
drivers/media/pci/ivtv/ivtv-driver.c | 2 +-
drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 18 +++---
drivers/media/usb/s2255/s2255drv.c | 4 +-
drivers/net/ethernet/intel/i40e/i40e_main.c | 7 +--
drivers/net/ethernet/marvell/sky2.c | 2 +-
drivers/net/ethernet/sun/sunvnet.c | 2 +-
drivers/net/usb/sierra_net.c | 2 +-
drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 2 +-
drivers/net/wireless/intersil/hostap/hostap_ap.c | 2 +-
drivers/net/wireless/marvell/mwifiex/main.c | 2 +-
drivers/net/wireless/microchip/wilc1000/hif.c | 6 +-
drivers/nfc/pn533/pn533.c | 2 +-
drivers/nfc/pn533/uart.c | 2 +-
drivers/pcmcia/bcm63xx_pcmcia.c | 2 +-
drivers/pcmcia/electra_cf.c | 2 +-
drivers/pcmcia/omap_cf.c | 2 +-
drivers/pcmcia/pd6729.c | 4 +-
drivers/pcmcia/yenta_socket.c | 4 +-
drivers/scsi/qla2xxx/qla_edif.c | 4 +-
drivers/staging/media/atomisp/i2c/atomisp-lm3554.c | 2 +-
drivers/tty/n_gsm.c | 2 +-
drivers/tty/sysrq.c | 2 +-
drivers/usb/gadget/udc/m66592-udc.c | 2 +-
drivers/usb/serial/garmin_gps.c | 2 +-
drivers/usb/serial/mos7840.c | 2 +-
fs/ext4/super.c | 2 +-
fs/jbd2/journal.c | 2 +
fs/nilfs2/segment.c | 2 +-
include/linux/timer.h | 64 +++++++++++++++++++---
kernel/sched/psi.c | 1 +
kernel/time/timer.c | 64 ++++++++++++----------
kernel/workqueue.c | 4 +-
net/802/garp.c | 2 +-
net/802/mrp.c | 2 +-
net/bridge/br_multicast.c | 6 +-
net/bridge/br_multicast_eht.c | 4 +-
net/core/gen_estimator.c | 2 +-
net/core/neighbour.c | 2 +
net/ipv4/inet_timewait_sock.c | 1 +
net/ipv4/ipmr.c | 2 +-
net/ipv6/ip6mr.c | 2 +-
net/mac80211/mesh_pathtbl.c | 2 +-
net/netfilter/ipset/ip_set_list_set.c | 2 +-
net/netfilter/ipvs/ip_vs_lblc.c | 2 +-
net/netfilter/ipvs/ip_vs_lblcr.c | 2 +-
net/netfilter/xt_LED.c | 2 +-
net/rxrpc/conn_object.c | 2 +-
net/sched/cls_flow.c | 2 +-
net/sunrpc/svc.c | 2 +-
net/sunrpc/xprt.c | 2 +-
net/tipc/discover.c | 2 +-
net/tipc/monitor.c | 2 +-
sound/i2c/other/ak4117.c | 2 +-
sound/synth/emux/emux.c | 2 +-
93 files changed, 227 insertions(+), 169 deletions(-)