s390/unwind: introduce stack unwind API

Rework the dump_trace() stack unwinder interface to support different
unwinding algorithms. The new interface looks like this:

	struct unwind_state state;
	unwind_for_each_frame(&state, task, regs, start_stack)
		do_something(state.sp, state.ip, state.reliable);

The unwind_bc.c file contains the implementation for the classic
back-chain unwinder.

One positive side effect of the new code is it now handles ftraced
functions gracefully. It prints the real name of the return function
instead of 'return_to_handler'.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 0 insertions, 72 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 8aa85e39f50b..9f2ff4a54aff 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -156,25 +156,6 @@ struct thread_struct {
 
 typedef struct thread_struct thread_struct;
 
-/*
- * Stack layout of a C stack frame.
- */
-#ifndef __PACK_STACK
-struct stack_frame {
-	unsigned long back_chain;
-	unsigned long empty1[5];
-	unsigned long gprs[10];
-	unsigned int  empty2[8];
-};
-#else
-struct stack_frame {
-	unsigned long empty1[5];
-	unsigned int  empty2[8];
-	unsigned long gprs[10];
-	unsigned long back_chain;
-};
-#endif
-
 #define ARCH_MIN_TASKALIGN	8
 
 #define INIT_THREAD {							\
@@ -206,11 +187,7 @@ struct mm_struct;
 struct seq_file;
 struct pt_regs;
 
-typedef int (*dump_trace_func_t)(void *data, unsigned long address, int reliable);
-void dump_trace(dump_trace_func_t func, void *data,
-		struct task_struct *task, unsigned long sp);
 void show_registers(struct pt_regs *regs);
-
 void show_cacheinfo(struct seq_file *m);
 
 /* Free all resources held by a thread. */
@@ -244,55 +221,6 @@ static __no_kasan_or_inline unsigned short stap(void)
 	return cpu_address;
 }
 
-#define CALL_ARGS_0()							\
-	register unsigned long r2 asm("2")
-#define CALL_ARGS_1(arg1)						\
-	register unsigned long r2 asm("2") = (unsigned long)(arg1)
-#define CALL_ARGS_2(arg1, arg2)						\
-	CALL_ARGS_1(arg1);						\
-	register unsigned long r3 asm("3") = (unsigned long)(arg2)
-#define CALL_ARGS_3(arg1, arg2, arg3)					\
-	CALL_ARGS_2(arg1, arg2);					\
-	register unsigned long r4 asm("4") = (unsigned long)(arg3)
-#define CALL_ARGS_4(arg1, arg2, arg3, arg4)				\
-	CALL_ARGS_3(arg1, arg2, arg3);					\
-	register unsigned long r4 asm("5") = (unsigned long)(arg4)
-#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5)			\
-	CALL_ARGS_4(arg1, arg2, arg3, arg4);				\
-	register unsigned long r4 asm("6") = (unsigned long)(arg5)
-
-#define CALL_FMT_0 "=&d" (r2) :
-#define CALL_FMT_1 "+&d" (r2) :
-#define CALL_FMT_2 CALL_FMT_1 "d" (r3),
-#define CALL_FMT_3 CALL_FMT_2 "d" (r4),
-#define CALL_FMT_4 CALL_FMT_3 "d" (r5),
-#define CALL_FMT_5 CALL_FMT_4 "d" (r6),
-
-#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
-#define CALL_CLOBBER_4 CALL_CLOBBER_5
-#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
-#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
-#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
-#define CALL_CLOBBER_0 CALL_CLOBBER_1
-
-#define CALL_ON_STACK(fn, stack, nr, args...)				\
-({									\
-	CALL_ARGS_##nr(args);						\
-	unsigned long prev;						\
-									\
-	asm volatile(							\
-		"	la	%[_prev],0(15)\n"			\
-		"	la	15,0(%[_stack])\n"			\
-		"	stg	%[_prev],%[_bc](15)\n"			\
-		"	brasl	14,%[_fn]\n"				\
-		"	la	15,0(%[_prev])\n"			\
-		: [_prev] "=&a" (prev), CALL_FMT_##nr			\
-		  [_stack] "a" (stack),					\
-		  [_bc] "i" (offsetof(struct stack_frame, back_chain)),	\
-		  [_fn] "X" (fn) : CALL_CLOBBER_##nr);			\
-	r2;								\
-})
-
 /*
  * Give up the time slice of the virtual PU.
  */