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author | Ira Weiny <ira.weiny@intel.com> | 2022-10-06 07:05:55 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-13 04:51:51 +0300 |
commit | ef6e06b2ef87077104d1145a0fd452ff8dbbc4b7 (patch) | |
tree | 57c08d46dad37f9879db3cedc124799973d36f38 /mm/page_alloc.c | |
parent | 15cd90049d595e592d8860ee15a3f23491d54d17 (diff) | |
download | linux-ef6e06b2ef87077104d1145a0fd452ff8dbbc4b7.tar.xz |
highmem: fix kmap_to_page() for kmap_local_page() addresses
kmap_to_page() is used to get the page for a virtual address which may
be kmap'ed. Unfortunately, kmap_local_page() stores mappings in a
thread local array separate from kmap(). These mappings were not
checked by the call.
Check the kmap_local_page() mappings and return the page if found.
Because it is intended to remove kmap_to_page() add a warn on once to
the kmap checks to flag potential issues early.
NOTE Due to 32bit x86 use of kmap local in iomap atmoic, KMAP_LOCAL does
not require HIGHMEM to be set. Therefore the support calls required a
new KMAP_LOCAL section to fix 0day build errors.
[akpm@linux-foundation.org: fix warning]
Link: https://lkml.kernel.org/r/20221006040555.1502679-1-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: kernel test robot <lkp@intel.com>
Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
0 files changed, 0 insertions, 0 deletions