stacktrace.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_S390_STACKTRACE_H
  3#define _ASM_S390_STACKTRACE_H
  4
  5#include <linux/stacktrace.h>
  6#include <linux/uaccess.h>
  7#include <linux/ptrace.h>
  8
  9struct stack_frame_user {
 10	unsigned long back_chain;
 11	unsigned long empty1[5];
 12	unsigned long gprs[10];
 13	unsigned long empty2[4];
 14};
 15
 16struct stack_frame_vdso_wrapper {
 17	struct stack_frame_user sf;
 18	unsigned long return_address;
 19};
 20
 21struct perf_callchain_entry_ctx;
 22
 23void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *cookie,
 24				 struct perf_callchain_entry_ctx *entry,
 25				 const struct pt_regs *regs, bool perf);
 26
 27enum stack_type {
 28	STACK_TYPE_UNKNOWN,
 29	STACK_TYPE_TASK,
 30	STACK_TYPE_IRQ,
 31	STACK_TYPE_NODAT,
 32	STACK_TYPE_RESTART,
 33	STACK_TYPE_MCCK,
 34};
 35
 36struct stack_info {
 37	enum stack_type type;
 38	unsigned long begin, end;
 39};
 40
 41const char *stack_type_name(enum stack_type type);
 42int get_stack_info(unsigned long sp, struct task_struct *task,
 43		   struct stack_info *info, unsigned long *visit_mask);
 44
 45static inline bool on_stack(struct stack_info *info,
 46			    unsigned long addr, size_t len)
 47{
 48	if (info->type == STACK_TYPE_UNKNOWN)
 49		return false;
 50	if (addr + len < addr)
 51		return false;
 52	return addr >= info->begin && addr + len <= info->end;
 53}
 54
 55/*
 56 * Stack layout of a C stack frame.
 57 * Kernel uses the packed stack layout (-mpacked-stack).
 58 */
 59struct stack_frame {
 60	union {
 61		unsigned long empty[9];
 62		struct {
 63			unsigned long sie_control_block;
 64			unsigned long sie_savearea;
 65			unsigned long sie_reason;
 66			unsigned long sie_flags;
 67			unsigned long sie_control_block_phys;
 68			unsigned long sie_guest_asce;
 69			unsigned long sie_irq;
 70		};
 71	};
 72	unsigned long gprs[10];
 73	unsigned long back_chain;
 74};
 75
 76/*
 77 * Unlike current_stack_pointer which simply contains the current value of %r15
 78 * current_frame_address() returns function stack frame address, which matches
 79 * %r15 upon function invocation. It may differ from %r15 later if function
 80 * allocates stack for local variables or new stack frame to call other
 81 * functions.
 82 */
 83#define current_frame_address()						\
 84	((unsigned long)__builtin_frame_address(0) -			\
 85	 offsetof(struct stack_frame, back_chain))
 86
 87static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
 88						       struct pt_regs *regs)
 89{
 90	if (regs)
 91		return (unsigned long)kernel_stack_pointer(regs);
 92	if (task == current)
 93		return current_frame_address();
 94	return (unsigned long)task->thread.ksp;
 95}
 96
 97/*
 98 * To keep this simple mark register 2-6 as being changed (volatile)
 99 * by the called function, even though register 6 is saved/nonvolatile.
100 */
101#define CALL_FMT_0 "=&d" (r2)
102#define CALL_FMT_1 "+&d" (r2)
103#define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
104#define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
105#define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
106#define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
107
108#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
109#define CALL_CLOBBER_4 CALL_CLOBBER_5
110#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
111#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
112#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
113#define CALL_CLOBBER_0 CALL_CLOBBER_1
114
115#define CALL_LARGS_0(...)						\
116	long dummy = 0
117#define CALL_LARGS_1(t1, a1)						\
118	long arg1  = (long)(t1)(a1)
119#define CALL_LARGS_2(t1, a1, t2, a2)					\
120	CALL_LARGS_1(t1, a1);						\
121	long arg2 = (long)(t2)(a2)
122#define CALL_LARGS_3(t1, a1, t2, a2, t3, a3)				\
123	CALL_LARGS_2(t1, a1, t2, a2);					\
124	long arg3 = (long)(t3)(a3)
125#define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4)			\
126	CALL_LARGS_3(t1, a1, t2, a2, t3, a3);				\
127	long arg4  = (long)(t4)(a4)
128#define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5)		\
129	CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4);			\
130	long arg5 = (long)(t5)(a5)
131
132#define CALL_REGS_0							\
133	register long r2 asm("2") = dummy
134#define CALL_REGS_1							\
135	register long r2 asm("2") = arg1
136#define CALL_REGS_2							\
137	CALL_REGS_1;							\
138	register long r3 asm("3") = arg2
139#define CALL_REGS_3							\
140	CALL_REGS_2;							\
141	register long r4 asm("4") = arg3
142#define CALL_REGS_4							\
143	CALL_REGS_3;							\
144	register long r5 asm("5") = arg4
145#define CALL_REGS_5							\
146	CALL_REGS_4;							\
147	register long r6 asm("6") = arg5
148
149#define CALL_TYPECHECK_0(...)
150#define CALL_TYPECHECK_1(t, a, ...)					\
151	typecheck(t, a)
152#define CALL_TYPECHECK_2(t, a, ...)					\
153	CALL_TYPECHECK_1(__VA_ARGS__);					\
154	typecheck(t, a)
155#define CALL_TYPECHECK_3(t, a, ...)					\
156	CALL_TYPECHECK_2(__VA_ARGS__);					\
157	typecheck(t, a)
158#define CALL_TYPECHECK_4(t, a, ...)					\
159	CALL_TYPECHECK_3(__VA_ARGS__);					\
160	typecheck(t, a)
161#define CALL_TYPECHECK_5(t, a, ...)					\
162	CALL_TYPECHECK_4(__VA_ARGS__);					\
163	typecheck(t, a)
164
165#define CALL_PARM_0(...) void
166#define CALL_PARM_1(t, a, ...) t
167#define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
168#define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
169#define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
170#define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
171#define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
172
173/*
174 * Use call_on_stack() to call a function switching to a specified
175 * stack. Proper sign and zero extension of function arguments is
176 * done. Usage:
177 *
178 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
179 *
180 * - nr specifies the number of function arguments of fn.
181 * - stack specifies the stack to be used.
182 * - fn is the function to be called.
183 * - rettype is the return type of fn.
184 * - t1, a1, ... are pairs, where t1 must match the type of the first
185 *   argument of fn, t2 the second, etc. a1 is the corresponding
186 *   first function argument (not name), etc.
187 */
188#define call_on_stack(nr, stack, rettype, fn, ...)			\
189({									\
190	rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn;		\
191	unsigned long frame = current_frame_address();			\
192	unsigned long __stack = stack;					\
193	unsigned long prev;						\
194	CALL_LARGS_##nr(__VA_ARGS__);					\
195	CALL_REGS_##nr;							\
196									\
197	CALL_TYPECHECK_##nr(__VA_ARGS__);				\
198	asm volatile(							\
199		"	lgr	%[_prev],15\n"				\
200		"	lg	15,%[_stack]\n"				\
201		"	stg	%[_frame],%[_bc](15)\n"			\
202		"	brasl	14,%[_fn]\n"				\
203		"	lgr	15,%[_prev]"				\
204		: [_prev] "=&d" (prev), CALL_FMT_##nr			\
205		: [_stack] "R" (__stack),				\
206		  [_bc] "i" (offsetof(struct stack_frame, back_chain)),	\
207		  [_frame] "d" (frame),					\
208		  [_fn] "X" (__fn) : CALL_CLOBBER_##nr);		\
209	(rettype)r2;							\
210})
211
212/*
213 * Use call_nodat() to call a function with DAT disabled.
214 * Proper sign and zero extension of function arguments is done.
215 * Usage:
216 *
217 * rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...)
218 *
219 * - nr specifies the number of function arguments of fn.
220 * - fn is the function to be called, where fn is a physical address.
221 * - rettype is the return type of fn.
222 * - t1, a1, ... are pairs, where t1 must match the type of the first
223 *   argument of fn, t2 the second, etc. a1 is the corresponding
224 *   first function argument (not name), etc.
225 *
226 * fn() is called with standard C function call ABI, with the exception
227 * that no useful stackframe or stackpointer is passed via register 15.
228 * Therefore the called function must not use r15 to access the stack.
229 */
230#define call_nodat(nr, rettype, fn, ...)				\
231({									\
232	rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn);		\
233	/* aligned since psw_leave must not cross page boundary */	\
234	psw_t __aligned(16) psw_leave;					\
235	psw_t psw_enter;						\
236	CALL_LARGS_##nr(__VA_ARGS__);					\
237	CALL_REGS_##nr;							\
238									\
239	CALL_TYPECHECK_##nr(__VA_ARGS__);				\
240	psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT;		\
241	psw_enter.addr = (unsigned long)__fn;				\
242	asm volatile(							\
243		"	epsw	0,1\n"					\
244		"	risbg	1,0,0,31,32\n"				\
245		"	larl	7,1f\n"					\
246		"	stg	1,%[psw_leave]\n"			\
247		"	stg	7,8+%[psw_leave]\n"			\
248		"	la	7,%[psw_leave]\n"			\
249		"	lra	7,0(7)\n"				\
250		"	larl	1,0f\n"					\
251		"	lra	14,0(1)\n"				\
252		"	lpswe	%[psw_enter]\n"				\
253		"0:	lpswe	0(7)\n"					\
254		"1:"							\
255		: CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave)		\
256		: [psw_enter] "Q" (psw_enter)				\
257		: "7", CALL_CLOBBER_##nr);				\
258	(rettype)r2;							\
259})
260
261#endif /* _ASM_S390_STACKTRACE_H */