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| author |   Minchan Kim <minchan@kernel.org> | 2014-12-12 16:56:58 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:50 -0800 |
| commit | af4ee5e977acb150371c28bd85cb7e34cac48b13 (patch) | |
| tree | 67463f79cabacffded1af15a140e8e8030502c41 /mm/sparse.c | |
| parent | zsmalloc: fix zs_init cpu notifier error handling (diff) | |
| download | linux-dev-af4ee5e977acb150371c28bd85cb7e34cac48b13.tar.xz linux-dev-af4ee5e977acb150371c28bd85cb7e34cac48b13.zip | |
zsmalloc: correct fragile [kmap|kunmap]_atomic use
The kunmap_atomic should use virtual address getting by kmap_atomic.
However, some pieces of code in zsmalloc uses modified address, not the
one got by kmap_atomic for kunmap_atomic.
It's okay for working because zsmalloc modifies the address inner
PAGE_SIZE bounday so it works with current kmap_atomic's implementation.
But it's still fragile with potential changing of kmap_atomic so let's
correct it.
I got a subtle bug when I implemented a new feature of zsmalloc
(compaction) due to a link's mishandling (the link was over page
boundary). Although it was totally my mistake, it took a while to find
the cause because an unpredictable kmapped address was unmapped causing an
almost random crash.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/sparse.c')
0 files changed, 0 insertions, 0 deletions