linux/include
Michael J. Ruhl e0b3e0b1a0 io-mapping: indicate mapping failure
The !ATOMIC_IOMAP version of io_maping_init_wc will always return
success, even when the ioremap fails.

Since the ATOMIC_IOMAP version returns NULL when the init fails, and
callers check for a NULL return on error this is unexpected.

During a device probe, where the ioremap failed, a crash can look like
this:

    BUG: unable to handle page fault for address: 0000000000210000
     #PF: supervisor write access in kernel mode
     #PF: error_code(0x0002) - not-present page
     Oops: 0002 [#1] PREEMPT SMP
     CPU: 0 PID: 177 Comm:
     RIP: 0010:fill_page_dma [i915]
       gen8_ppgtt_create [i915]
       i915_ppgtt_create [i915]
       intel_gt_init [i915]
       i915_gem_init [i915]
       i915_driver_probe [i915]
       pci_device_probe
       really_probe
       driver_probe_device

The remap failure occurred much earlier in the probe.  If it had been
propagated, the driver would have exited with an error.

Return NULL on ioremap failure.

[akpm@linux-foundation.org: detect ioremap_wc() errors earlier]

Fixes: cafaf14a5d ("io-mapping: Always create a struct to hold metadata about the io-mapping")
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200721171936.81563-1-michael.j.ruhl@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-24 12:42:42 -07:00
..
acpi Merge branch 'acpica' 2020-06-10 17:27:28 +02:00
asm-generic arm64 fixes for -rc6 2020-07-17 15:27:52 -07:00
clocksource
crypto crypto: af_alg - fix use-after-free in af_alg_accept() due to bh_lock_sock() 2020-06-18 17:09:54 +10:00
drm drm/edid: Replace zero-length array with flexible-array 2020-06-15 23:08:31 -05:00
dt-bindings - qcom : 2020-06-11 12:42:14 -07:00
keys RxRPC: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
kunit
kvm
linux io-mapping: indicate mapping failure 2020-07-24 12:42:42 -07:00
math-emu
media media updates for v5.8-rc1 2020-06-13 13:09:38 -07:00
misc
net bpf: net: Avoid incorrect bpf_sk_reuseport_detach call 2020-07-09 22:03:31 +02:00
pcmcia
ras
rdma dynamic_debug: add an option to enable dynamic debug for modules only 2020-06-08 11:05:56 -07:00
scsi SCSI misc on 20200605 2020-06-05 15:11:50 -07:00
soc pci-v5.8-changes 2020-06-06 11:01:58 -07:00
sound ASoC: Fixes for v5.8 2020-07-17 18:19:02 +02:00
target scsi: target: Rename target_setup_cmd_from_cdb() to target_cmd_parse_cdb() 2020-06-09 21:57:26 -04:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-25 18:27:40 -07:00
uapi Char/Misc fixes for 5.8-rc6 2020-07-16 11:26:40 -07:00
vdso
video
xen xen: Move xen_setup_callback_vector() definition to include/xen/hvm.h 2020-06-11 15:15:19 +02:00