Merge tag 'mips_5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

[sfrench/cifs-2.6.git] / arch / parisc / kernel / ptrace.c

diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index 0964c236e3e5a711056e058a8a5ee63343f9a496..a3d2fb4e6dd2670f05639fc6e3598096611947c1 100644 (file)
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -789,3 +789,38 @@ const char *regs_query_register_name(unsigned int offset)
                        return roff->name;
        return NULL;
 }
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs:      pt_regs which contains kernel stack pointer.
+ * @addr:      address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+       return ((addr & ~(THREAD_SIZE - 1))  ==
+               (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:      pt_regs which contains kernel stack pointer.
+ * @n:         stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+       unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+       addr -= n;
+
+       if (!regs_within_kernel_stack(regs, (unsigned long)addr))
+               return 0;
+
+       return *addr;
+}