linux/include
Ahmed S. Darwish 58bdc321be scsi: libsas: Introduce a _gfp() variant of event notifiers
[ Upstream commit c2d0f1a65a ]

sas_alloc_event() uses in_interrupt() to decide which allocation should be
used.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

The in_interrupt() check is also only partially correct, because it fails
to choose the correct code path when just preemption or interrupts are
disabled. For example, as in the following call chain:

  mvsas/mv_sas.c: mvs_work_queue() [process context]
  spin_lock_irqsave(mvs_info::lock, )
    -> libsas/sas_event.c: sas_notify_phy_event()
      -> sas_alloc_event()
        -> in_interrupt() = false
          -> invalid GFP_KERNEL allocation
    -> libsas/sas_event.c: sas_notify_port_event()
      -> sas_alloc_event()
        -> in_interrupt() = false
          -> invalid GFP_KERNEL allocation

Introduce sas_alloc_event_gfp(), sas_notify_port_event_gfp(), and
sas_notify_phy_event_gfp(), which all behave like the non _gfp() variants
but use a caller-passed GFP mask for allocations.

For bisectability, all callers will be modified first to pass GFP context,
then the non _gfp() libsas API variants will be modified to take a gfp_t by
default.

Link: https://lore.kernel.org/r/20210118100955.1761652-4-a.darwish@linutronix.de
Fixes: 1c393b970e ("scsi: libsas: Use dynamic alloced work to avoid sas event lost")
Cc: Jason Yan <yanaijie@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:11 +01:00
..
acpi ACPICA: Fix exception code class checks 2021-03-04 11:37:24 +01:00
asm-generic vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y 2021-03-04 11:37:19 +01:00
clocksource
crypto crypto - shash: reduce minimum alignment of shash_desc structure 2021-03-09 11:11:13 +01:00
drm drm/dp/mst: Export drm_dp_get_vc_payload_bw() 2021-02-10 09:29:18 +01:00
dt-bindings ASoC: dt-bindings: lpass: Fix and common up lpass dai ids 2021-02-03 23:28:46 +01:00
keys
kunit kunit: fix display of failed expectations for strings 2020-11-10 13:45:15 -07:00
kvm
linux bpf: Declare __bpf_free_used_maps() unconditionally 2021-03-25 09:04:10 +01:00
math-emu
media media: rc: compile rc-cec.c into rc-core 2021-03-17 17:06:20 +01:00
memory
misc
net Bluetooth: Add new HCI_QUIRK_NO_SUSPEND_NOTIFIER quirk 2021-03-07 12:34:10 +01:00
pcmcia
ras
rdma RDMA: Lift ibdev_to_node from rds to common code 2021-02-26 10:12:59 +01:00
scsi scsi: libsas: Introduce a _gfp() variant of event notifiers 2021-03-25 09:04:11 +01:00
soc net: dsa: felix: implement port flushing on .phylink_mac_link_down 2021-02-17 11:02:27 +01:00
sound ALSA: hda: intel-nhlt: verify config type 2021-03-09 11:11:14 +01:00
target scsi: target: core: Add cmd length set before cmd complete 2021-03-17 17:06:25 +01:00
trace trace: fix potenial dangerous pointer 2020-11-25 13:03:44 +01:00
uapi net: l2tp: reduce log level of messages in receive path, add counter instead 2021-03-17 17:06:11 +01:00
vdso
video gpu: ipu-v3: remove unused functions 2020-10-26 10:42:38 +01:00
xen Xen/gntdev: correct error checking in gntdev_map_grant_pages() 2021-02-23 15:53:24 +01:00