1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_S390_STACKTRACE_H 3 #define _ASM_S390_STACKTRACE_H 4 5 #include <linux/uaccess.h> 6 #include <linux/ptrace.h> 7 #include <asm/switch_to.h> 8 9 enum stack_type { 10 STACK_TYPE_UNKNOWN, 11 STACK_TYPE_TASK, 12 STACK_TYPE_IRQ, 13 STACK_TYPE_NODAT, 14 STACK_TYPE_RESTART, 15 STACK_TYPE_MCCK, 16 }; 17 18 struct stack_info { 19 enum stack_type type; 20 unsigned long begin, end; 21 }; 22 23 const char *stack_type_name(enum stack_type type); 24 int get_stack_info(unsigned long sp, struct task_struct *task, 25 struct stack_info *info, unsigned long *visit_mask); 26 27 static inline bool on_stack(struct stack_info *info, 28 unsigned long addr, size_t len) 29 { 30 if (info->type == STACK_TYPE_UNKNOWN) 31 return false; 32 if (addr + len < addr) 33 return false; 34 return addr >= info->begin && addr + len <= info->end; 35 } 36 37 static __always_inline unsigned long get_stack_pointer(struct task_struct *task, 38 struct pt_regs *regs) 39 { 40 if (regs) 41 return (unsigned long) kernel_stack_pointer(regs); 42 if (task == current) 43 return current_stack_pointer(); 44 return (unsigned long) task->thread.ksp; 45 } 46 47 /* 48 * Stack layout of a C stack frame. 49 */ 50 #ifndef __PACK_STACK 51 struct stack_frame { 52 unsigned long back_chain; 53 unsigned long empty1[5]; 54 unsigned long gprs[10]; 55 unsigned int empty2[8]; 56 }; 57 #else 58 struct stack_frame { 59 unsigned long empty1[5]; 60 unsigned int empty2[8]; 61 unsigned long gprs[10]; 62 unsigned long back_chain; 63 }; 64 #endif 65 66 /* 67 * Unlike current_stack_pointer() which simply returns current value of %r15 68 * current_frame_address() returns function stack frame address, which matches 69 * %r15 upon function invocation. It may differ from %r15 later if function 70 * allocates stack for local variables or new stack frame to call other 71 * functions. 72 */ 73 #define current_frame_address() \ 74 ((unsigned long)__builtin_frame_address(0) - \ 75 offsetof(struct stack_frame, back_chain)) 76 77 /* 78 * To keep this simple mark register 2-6 as being changed (volatile) 79 * by the called function, even though register 6 is saved/nonvolatile. 80 */ 81 #define CALL_FMT_0 "=&d" (r2) 82 #define CALL_FMT_1 "+&d" (r2) 83 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3) 84 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4) 85 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5) 86 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6) 87 88 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" 89 #define CALL_CLOBBER_4 CALL_CLOBBER_5 90 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" 91 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" 92 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" 93 #define CALL_CLOBBER_0 CALL_CLOBBER_1 94 95 #define CALL_LARGS_0(...) \ 96 long dummy = 0 97 #define CALL_LARGS_1(t1, a1) \ 98 long arg1 = (long)(t1)(a1) 99 #define CALL_LARGS_2(t1, a1, t2, a2) \ 100 CALL_LARGS_1(t1, a1); \ 101 long arg2 = (long)(t2)(a2) 102 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \ 103 CALL_LARGS_2(t1, a1, t2, a2); \ 104 long arg3 = (long)(t3)(a3) 105 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \ 106 CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \ 107 long arg4 = (long)(t4)(a4) 108 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \ 109 CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \ 110 long arg5 = (long)(t5)(a5) 111 112 #define CALL_REGS_0 \ 113 register long r2 asm("2") = dummy 114 #define CALL_REGS_1 \ 115 register long r2 asm("2") = arg1 116 #define CALL_REGS_2 \ 117 CALL_REGS_1; \ 118 register long r3 asm("3") = arg2 119 #define CALL_REGS_3 \ 120 CALL_REGS_2; \ 121 register long r4 asm("4") = arg3 122 #define CALL_REGS_4 \ 123 CALL_REGS_3; \ 124 register long r5 asm("5") = arg4 125 #define CALL_REGS_5 \ 126 CALL_REGS_4; \ 127 register long r6 asm("6") = arg5 128 129 #define CALL_TYPECHECK_0(...) 130 #define CALL_TYPECHECK_1(t, a, ...) \ 131 typecheck(t, a) 132 #define CALL_TYPECHECK_2(t, a, ...) \ 133 CALL_TYPECHECK_1(__VA_ARGS__); \ 134 typecheck(t, a) 135 #define CALL_TYPECHECK_3(t, a, ...) \ 136 CALL_TYPECHECK_2(__VA_ARGS__); \ 137 typecheck(t, a) 138 #define CALL_TYPECHECK_4(t, a, ...) \ 139 CALL_TYPECHECK_3(__VA_ARGS__); \ 140 typecheck(t, a) 141 #define CALL_TYPECHECK_5(t, a, ...) \ 142 CALL_TYPECHECK_4(__VA_ARGS__); \ 143 typecheck(t, a) 144 145 #define CALL_PARM_0(...) void 146 #define CALL_PARM_1(t, a, ...) t 147 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__) 148 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__) 149 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__) 150 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__) 151 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__) 152 153 /* 154 * Use call_on_stack() to call a function switching to a specified 155 * stack. Proper sign and zero extension of function arguments is 156 * done. Usage: 157 * 158 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...) 159 * 160 * - nr specifies the number of function arguments of fn. 161 * - stack specifies the stack to be used. 162 * - fn is the function to be called. 163 * - rettype is the return type of fn. 164 * - t1, a1, ... are pairs, where t1 must match the type of the first 165 * argument of fn, t2 the second, etc. a1 is the corresponding 166 * first function argument (not name), etc. 167 */ 168 #define call_on_stack(nr, stack, rettype, fn, ...) \ 169 ({ \ 170 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \ 171 unsigned long frame = current_frame_address(); \ 172 unsigned long __stack = stack; \ 173 unsigned long prev; \ 174 CALL_LARGS_##nr(__VA_ARGS__); \ 175 CALL_REGS_##nr; \ 176 \ 177 CALL_TYPECHECK_##nr(__VA_ARGS__); \ 178 asm volatile( \ 179 " lgr %[_prev],15\n" \ 180 " lg 15,%[_stack]\n" \ 181 " stg %[_frame],%[_bc](15)\n" \ 182 " brasl 14,%[_fn]\n" \ 183 " lgr 15,%[_prev]\n" \ 184 : [_prev] "=&d" (prev), CALL_FMT_##nr \ 185 : [_stack] "R" (__stack), \ 186 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ 187 [_frame] "d" (frame), \ 188 [_fn] "X" (__fn) : CALL_CLOBBER_##nr); \ 189 (rettype)r2; \ 190 }) 191 192 #define call_on_stack_noreturn(fn, stack) \ 193 ({ \ 194 void (*__fn)(void) = fn; \ 195 \ 196 asm volatile( \ 197 " la 15,0(%[_stack])\n" \ 198 " xc %[_bc](8,15),%[_bc](15)\n" \ 199 " brasl 14,%[_fn]\n" \ 200 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \ 201 [_stack] "a" (stack), [_fn] "X" (__fn)); \ 202 BUG(); \ 203 }) 204 205 #endif /* _ASM_S390_STACKTRACE_H */ 206