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