From: Thomas Gleixner Date: Mon, 2 Apr 2007 12:25:31 +0000 (+0200) Subject: [PATCH] i386: fix file_read_actor() and pipe_read() for original i386 systems X-Git-Tag: v2.6.21-rc6~24 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b6a8b316c667f914c198a2de62e6729f359b7931;p=pandora-kernel.git [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 Acked-by: Ingo Molnar Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed