On Sun, Jan 12, 2014 at 05:20:00PM +0800, Qiaowei Ren wrote:Yes, I run this with lockdep enabled.+static bool allocate_bt(unsigned long bd_entry)
+{
+ unsigned long bt_size = 1UL << (MPX_L2_BITS+MPX_L2_SHIFT);
+ unsigned long bt_addr, old_val;
+
+ bt_addr = sys_mmap_pgoff(0, bt_size, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE | MAP_POPULATE, -1, 0);
Are we sure about this? We can do a possible memory allocation in
mmap_region() in this exception handler context. And yes, we do a
conditional_sti(), which makes it all the more susceptible.
Have you run this with lockdep enabled?