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-rw-r--r--arch/arm/kernel/process.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 401e38be1f78..e76fcaadce03 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -29,6 +29,7 @@
#include <linux/utsname.h>
#include <linux/uaccess.h>
#include <linux/random.h>
+#include <linux/hw_breakpoint.h>
#include <asm/cacheflush.h>
#include <asm/leds.h>
@@ -135,6 +136,25 @@ EXPORT_SYMBOL(pm_power_off);
void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
EXPORT_SYMBOL_GPL(arm_pm_restart);
+static void do_nothing(void *unused)
+{
+}
+
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
+void cpu_idle_wait(void)
+{
+ smp_mb();
+ /* kick all the CPUs so that they exit out of pm_idle */
+ smp_call_function(do_nothing, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(cpu_idle_wait);
/*
* This is our default idle handler. We need to disable
@@ -317,6 +337,8 @@ void flush_thread(void)
struct thread_info *thread = current_thread_info();
struct task_struct *tsk = current;
+ flush_ptrace_hw_breakpoint(tsk);
+
memset(thread->used_cp, 0, sizeof(thread->used_cp));
memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
memset(&thread->fpstate, 0, sizeof(union fp_state));
@@ -345,6 +367,8 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
thread->cpu_context.sp = (unsigned long)childregs;
thread->cpu_context.pc = (unsigned long)ret_from_fork;
+ clear_ptrace_hw_breakpoint(p);
+
if (clone_flags & CLONE_SETTLS)
thread->tp_value = regs->ARM_r3;
@@ -458,3 +482,24 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
unsigned long range_end = mm->brk + 0x02000000;
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}
+
+/*
+ * The vectors page is always readable from user space for the
+ * atomic helpers and the signal restart code. Let's declare a mapping
+ * for it so it is visible through ptrace and /proc/<pid>/mem.
+ */
+
+int vectors_user_mapping(void)
+{
+ struct mm_struct *mm = current->mm;
+ return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
+ VM_READ | VM_EXEC |
+ VM_MAYREAD | VM_MAYEXEC |
+ VM_ALWAYSDUMP | VM_RESERVED,
+ NULL);
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
+}