* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/ptrace.h>
if (in_interrupt() || !mm)
goto no_context;
- down_read(&mm->mmap_sem);
+ /*
+ * As per x86, we may deadlock here. However, since the kernel only
+ * validly references user space from well defined areas of the code,
+ * we can bug out early if this is from code which shouldn't.
+ */
+ if (!down_read_trylock(&mm->mmap_sem)) {
+ if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc))
+ goto no_context;
+ down_read(&mm->mmap_sem);
+ }
+
fault = __do_page_fault(mm, addr, fsr, tsk);
up_read(&mm->mmap_sem);
/*
- * Handle the "normal" case first
+ * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
*/
- if (fault > 0)
+ if (fault >= VM_FAULT_MINOR)
return 0;
/*
do_exit(SIGKILL);
return 0;
- case 0:
+ case VM_FAULT_SIGBUS:
/*
* We had some memory, but were unable to
* successfully fix up this page fault.