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author | Chris Metcalf <cmetcalf@tilera.com> | 2012-04-29 02:51:43 +0400 |
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committer | Chris Metcalf <cmetcalf@tilera.com> | 2012-05-17 00:01:16 +0400 |
commit | fc327e268fbef08e129ad51aa3a7113ee9bc6ba5 (patch) | |
tree | ba75f2ac9509090c6896a4fbc6be7c3aaba1aaf6 /arch/alpha/include/asm/mc146818rtc.h | |
parent | 36be50515fe2aef61533b516fa2576a2c7fe7664 (diff) | |
download | linux-fc327e268fbef08e129ad51aa3a7113ee9bc6ba5.tar.xz |
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 <viro@ZenIV.linux.org.uk>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/alpha/include/asm/mc146818rtc.h')
0 files changed, 0 insertions, 0 deletions