Revision e0b3e0b1a04367fc15c07f44e78361545b55357c authored by Michael J. Ruhl on 24 July 2020, 04:15:46 UTC, committed by Linus Torvalds on 24 July 2020, 19:42:42 UTC
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: cafaf14a5d8f ("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>
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certs | ||
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drivers | ||
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include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
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net | ||
samples | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.8 KB |
.mailmap | -rw-r--r-- | 15.9 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 97.4 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 548.0 KB |
Makefile | -rw-r--r-- | 60.4 KB |
README | -rw-r--r-- | 727 bytes |
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