Linaro-mm-sig

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[PATCH v7 00/21] Move all drivers to a common dma-buf locking convention

by Dmitry Osipenko

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

3 years, 6 months

[PATCH v4a 00/38] timers: Use timer_shutdown*() before freeing timers

by Steven Rostedt

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(-)

3 years, 6 months

[RFC][PATCH v3 00/33] timers: Use timer_shutdown*() before freeing timers

by Steven Rostedt

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. This is v3 of that patch set. Thomas Gleixner posted an untested version that makes timer->function NULL as the flag that it is shutdown. I took that code, tested it (fixed it up), added more comments, and changed the name to timer_shutdown_sync(). I also converted it to use WARN_ON_ONCE() instead of just WARN_ON() as Linus asked for. I then created a trivial coccinelle script to find where del_timer*() is called before being freed, and converted them all to timer_shutdown*() (There was a couple that still used del_timer() instead of del_timer_sync()). I also updated DEBUG_OBJECTS_TIMERS to check from where the timer is ever armed, to calling of timer_shutdown_sync(), and it will trigger if a timer is freed in between. The current way is to only check if the timer is armed, but that means it only triggers if the race condition is hit, and with experience, it's not run on enough machines to catch all of them. By triggering it from the time the timer is armed to the time it is shutdown, it catches all potential cases even if the race condition is not hit. I went though the result of the cocinelle script, and updated the locations. Some locations were caught by DEBUG_OBJECTS_TIMERS as the coccinelle script only checked for timers being freed in the same function as the del_timer*(). Ideally, I would have the first patch go into this rc cycle, which is mostly non functional as it will allow the other patches to come in via the respective subsystems in the next merge window. Changes since v2: https://lore.kernel.org/all/20221027150525.753064657@goodmis.org/ - Talking with Thomas Gleixner, he wanted a better name space and to remove the "del_" portion of the API. - Since there's now a shutdown interface that does not synchronize, to keep it closer to del_timer() and del_timer_sync(), the API is now: timer_shutdown() - same as del_timer() but deactivates the timer. timer_shutdown_sync() - same as del_timer_sync() but deactivates the timer. - Added a few more locations that got converted. git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git trace/timers Head SHA1: 25106f0bb7968b3e8c746a7853f44b51840746c3 Steven Rostedt (Google) (33): timers: Add timer_shutdown_sync() and timer_shutdown() to be called before freeing timers timers: s390/cmm: Use timer_shutdown_sync() before freeing timer 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: PM: Use timer_shutdown_sync() timers: Bluetooth: Use timer_shutdown_sync() before freeing timer timers: hangcheck: Use timer_shutdown_sync() before freeing timer timers: ipmi: Use timer_shutdown_sync() before freeing timer random: use timer_shutdown_sync() before freeing timer timers: dma-buf: 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: cgroup: Use timer_shutdown_sync() before freeing timer timers: workqueue: 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: x86/mce: Use __init_timer() for resetting timers timers: Expand DEBUG_OBJECTS_TIMER to check if it ever was used ---- .../RCU/Design/Requirements/Requirements.rst | 2 +- Documentation/core-api/local_ops.rst | 2 +- Documentation/kernel-hacking/locking.rst | 5 + arch/s390/mm/cmm.c | 4 +- arch/sh/drivers/push-switch.c | 2 +- arch/x86/kernel/cpu/mce/core.c | 14 ++- block/blk-iocost.c | 2 +- block/blk-iolatency.c | 2 +- block/blk-stat.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 | 2 +- drivers/bluetooth/hci_qca.c | 4 +- drivers/char/hangcheck-timer.c | 4 +- drivers/char/ipmi/ipmi_msghandler.c | 2 +- drivers/char/ipmi/ipmi_ssif.c | 4 +- drivers/char/random.c | 2 +- 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/input/serio/hp_sdc.c | 2 +- drivers/isdn/hardware/mISDN/hfcmulti.c | 6 +- drivers/isdn/mISDN/l1oip_core.c | 4 +- drivers/isdn/mISDN/timerdev.c | 4 +- drivers/leds/trigger/ledtrig-activity.c | 2 +- drivers/leds/trigger/ledtrig-heartbeat.c | 2 +- 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 | 6 +- 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 | 8 +- 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/scsi/scsi_lib.c | 1 + 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 | 100 +++++++++++++++++-- include/linux/workqueue.h | 4 +- kernel/cgroup/cgroup.c | 2 +- kernel/sched/psi.c | 1 + kernel/time/timer.c | 106 ++++++++++++++------- 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_connection_sock.c | 2 +- net/ipv4/inet_timewait_sock.c | 3 +- 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 +- 100 files changed, 310 insertions(+), 175 deletions(-)

3 years, 6 months

[PATCH v3] dma-buf: fix racing conflict of dma_heap_add()

by Dawei Li

Racing conflict could be: task A task B list_for_each_entry strcmp(h->name)) list_for_each_entry strcmp(h->name) kzalloc kzalloc ...... ..... device_create device_create list_add list_add The root cause is that task B has no idea about the fact someone else(A) has inserted heap with same name when it calls list_add, so a potential collision occurs. v1: https://lore.kernel.org/all/TYCP286MB2323950197F60FC3473123B7CA349@TYCP286M… v1->v2: Narrow down locking scope, check the existence of heap before insertion, as suggested by Andrew Davis. v2->v3: Remove double checking. Fixes: c02a81fba74f ("dma-buf: Add dma-buf heaps framework") base-commit: 447fb14bf07905b880c9ed1ea92c53d6dd0649d7 Signed-off-by: Dawei Li <set_pte_at(a)outlook.com> --- drivers/dma-buf/dma-heap.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 8f5848aa144f..7a25e98259ea 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -233,18 +233,6 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) return ERR_PTR(-EINVAL); } - /* check the name is unique */ - mutex_lock(&heap_list_lock); - list_for_each_entry(h, &heap_list, list) { - if (!strcmp(h->name, exp_info->name)) { - mutex_unlock(&heap_list_lock); - pr_err("dma_heap: Already registered heap named %s\n", - exp_info->name); - return ERR_PTR(-EINVAL); - } - } - mutex_unlock(&heap_list_lock); - heap = kzalloc(sizeof(*heap), GFP_KERNEL); if (!heap) return ERR_PTR(-ENOMEM); @@ -283,13 +271,26 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) err_ret = ERR_CAST(dev_ret); goto err2; } - /* Add heap to the list */ + mutex_lock(&heap_list_lock); + /* check the name is unique */ + list_for_each_entry(h, &heap_list, list) { + if (!strcmp(h->name, exp_info->name)) { + mutex_unlock(&heap_list_lock); + pr_err("dma_heap: Already registered heap named %s\n", + exp_info->name); + err_ret = ERR_PTR(-EINVAL); + goto err3; + } + } + + /* Add heap to the list */ list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock); return heap; - +err3: + device_destroy(dma_heap_class, heap->heap_devt); err2: cdev_del(&heap->heap_cdev); err1: -- 2.25.1

3 years, 6 months

[PATCH] drm/msm: Remove exclusive-fence hack

by Rob Clark

From: Rob Clark <robdclark(a)chromium.org> The workaround was initially necessary due to dma_resv having only a single exclusive fence slot, yet whe don't necessarily know what order the gpu scheduler will schedule jobs. Unfortunately this workaround also has the result of forcing implicit sync, even when userspace does not want it. However, since commit 047a1b877ed4 ("dma-buf & drm/amdgpu: remove dma_resv workaround") the workaround is no longer needed. So remove it. This effectively reverts commit f1b3f696a084 ("drm/msm: Don't break exclusive fence ordering") Signed-off-by: Rob Clark <robdclark(a)chromium.org> --- drivers/gpu/drm/msm/msm_gem_submit.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index 5599d93ec0d2..cc48f73adadf 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -334,8 +334,7 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit) if (ret) return ret; - /* exclusive fences must be ordered */ - if (no_implicit && !write) + if (no_implicit) continue; ret = drm_sched_job_add_implicit_dependencies(&submit->base, -- 2.38.1

3 years, 6 months

[PATCH v2] dma-buf: fix racing conflict of dma_heap_add()

by Dawei Li

Racing conflict could be: task A task B list_for_each_entry strcmp(h->name)) list_for_each_entry strcmp(h->name) kzalloc kzalloc ...... ..... device_create device_create list_add list_add The root cause is that task B has no idea about the fact someone else(A) has inserted heap with same name when it calls list_add, so a potential collision occurs. v1: https://lore.kernel.org/all/TYCP286MB2323950197F60FC3473123B7CA349@TYCP286M… v1->v2: Narrow down locking scope, check the existence of heap before insertion, as suggested by Andrew Davis. Fixes: c02a81fba74f ("dma-buf: Add dma-buf heaps framework") base-commit: 447fb14bf07905b880c9ed1ea92c53d6dd0649d7 Signed-off-by: Dawei Li <set_pte_at(a)outlook.com> --- drivers/dma-buf/dma-heap.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 8f5848aa144f..1c787a147e3a 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -216,9 +216,21 @@ const char *dma_heap_get_name(struct dma_heap *heap) return heap->name; } +static inline bool dma_heap_exist(const char *name) +{ + struct dma_heap *h; + + list_for_each_entry(h, &heap_list, list) { + if (!strcmp(h->name, name)) + return true; + } + + return false; +} + struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) { - struct dma_heap *heap, *h, *err_ret; + struct dma_heap *heap, *err_ret; struct device *dev_ret; unsigned int minor; int ret; @@ -235,13 +247,11 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) /* check the name is unique */ mutex_lock(&heap_list_lock); - list_for_each_entry(h, &heap_list, list) { - if (!strcmp(h->name, exp_info->name)) { - mutex_unlock(&heap_list_lock); - pr_err("dma_heap: Already registered heap named %s\n", - exp_info->name); - return ERR_PTR(-EINVAL); - } + if (dma_heap_exist(exp_info->name)) { + mutex_unlock(&heap_list_lock); + pr_err("dma_heap: Already registered heap named %s\n", + exp_info->name); + return ERR_PTR(-EINVAL); } mutex_unlock(&heap_list_lock); @@ -283,13 +293,22 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) err_ret = ERR_CAST(dev_ret); goto err2; } + /* Add heap to the list */ mutex_lock(&heap_list_lock); + if (unlikely(dma_heap_exist(exp_info->name))) { + mutex_unlock(&heap_list_lock); + pr_err("dma_heap: Already registered heap named %s\n", + exp_info->name); + err_ret = ERR_PTR(-EINVAL); + goto err3; + } list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock); return heap; - +err3: + device_destroy(dma_heap_class, heap->heap_devt); err2: cdev_del(&heap->heap_cdev); err1: -- 2.25.1

3 years, 6 months

[PATCH] drm/radeon: Replace kmap() with kmap_local_page()

by Fabio M. De Francesco

The use of kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as the mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Therefore, replace kmap() with kmap_local_page() in radeon_ttm_gtt_read(). Cc: "Venkataramanan, Anirudh" <anirudh.venkataramanan(a)intel.com> Suggested-by: Ira Weiny <ira.weiny(a)intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco(a)gmail.com> --- drivers/gpu/drm/radeon/radeon_ttm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c index d33fec488713..bdb4c0e0736b 100644 --- a/drivers/gpu/drm/radeon/radeon_ttm.c +++ b/drivers/gpu/drm/radeon/radeon_ttm.c @@ -869,11 +869,11 @@ static ssize_t radeon_ttm_gtt_read(struct file *f, char __user *buf, page = rdev->gart.pages[p]; if (page) { - ptr = kmap(page); + ptr = kmap_local_page(page); ptr += off; r = copy_to_user(buf, ptr, cur_size); - kunmap(rdev->gart.pages[p]); + kunmap_local(ptr); } else r = clear_user(buf, cur_size); -- 2.37.3

3 years, 6 months

[PATCH] dma-buf: fix racing conflict of dma_heap_add()

by Dawei Li

3 years, 6 months

[PATCH v2] dma-buf: cma_heap: Fix typo in comment

by Mark-PK Tsai

Remove duplicated "by" from comment in cma_heap_allocate(). Signed-off-by: Mark-PK Tsai <mark-pk.tsai(a)mediatek.com> --- drivers/dma-buf/heaps/cma_heap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 28fb04eccdd0..cd386ce639f3 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -316,7 +316,7 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap, kunmap_atomic(vaddr); /* * Avoid wasting time zeroing memory if the process - * has been killed by by SIGKILL + * has been killed by SIGKILL */ if (fatal_signal_pending(current)) goto free_cma; -- 2.18.0

3 years, 6 months

[PATCH v3] dma-buf: cma_heap: Remove duplicated 'by' in comment

by Mark-PK Tsai

Remove duplicated 'by' from comment in cma_heap_allocate(). Signed-off-by: Mark-PK Tsai <mark-pk.tsai(a)mediatek.com> --- drivers/dma-buf/heaps/cma_heap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 28fb04eccdd0..cd386ce639f3 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -316,7 +316,7 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap, kunmap_atomic(vaddr); /* * Avoid wasting time zeroing memory if the process - * has been killed by by SIGKILL + * has been killed by SIGKILL */ if (fatal_signal_pending(current)) goto free_cma; -- 2.18.0

3 years, 6 months

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