path: root/include
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authorThomas Gleixner <tglx@linutronix.de>2007-04-02 14:25:31 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-04-02 10:07:25 -0700
commitb6a8b316c667f914c198a2de62e6729f359b7931 (patch)
tree94b76fe47a5d7a65641ce6f60f789f3b095965b7 /include
parent[PATCH] vt: fix potential race in VT_WAITACTIVE handler (diff)
[PATCH] i386: fix file_read_actor() and pipe_read() for original i386 systems
The __copy_to_user_inatomic() calls in file_read_actor() and pipe_read() are broken on original i386 machines, where WP-works-ok == false, as __copy_to_user_inatomic() on such systems calls functions which might sleep and/or contain cond_resched() calls inside of a kmap_atomic() region. The original check for WP-works-ok was in access_ok(), but got moved during the 2.5 series to fix a race vs. swap. Return the number of bytes to copy in the case where we are in an atomic region, so the non atomic code pathes in file_read_actor() and pipe_read() are taken. This could be optimized to avoid the kmap_atomicby moving the check for WP-works-ok into fault_in_pages_writeable(), but this is more intrusive and can be done later. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
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