From: Chris Metcalf Date: Sat, 28 Apr 2012 22:51:43 +0000 (-0400) Subject: arch/tile: fix up some issues in calling do_work_pending() X-Git-Tag: v3.4~25^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fc327e268fbef08e129ad51aa3a7113ee9bc6ba5;p=pandora-kernel.git arch/tile: fix up some issues in calling do_work_pending() First, we were at risk of handling thread-info flags, in particular do_signal(), when returning from kernel space. This could happen after a failed kernel_execve(), or when forking a kernel thread. The fix is to test in do_work_pending() for user_mode() and return immediately if so; we already had this test for one of the flags, so I just hoisted it to the top of the function. Second, if a ptraced process updated the callee-saved registers in the ptregs struct and then processed another thread-info flag, we would overwrite the modifications with the original callee-saved registers. To fix this, we add a register to note if we've already saved the registers once, and skip doing it on additional passes through the loop. To avoid a performance hit from the couple of extra instructions involved, I modified the GET_THREAD_INFO() macro to be guaranteed to be one instruction, then bundled it with adjacent instructions, yielding an overall net savings. Reported-By: Al Viro Signed-off-by: Chris Metcalf --- Reading git-diff-tree failed