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 /* 38 * Stack layout of a C stack frame. 39 * Kernel uses the packed stack layout (-mpacked-stack). 40 */ 41 struct stack_frame { 42 union { 43 unsigned long empty[9]; 44 struct { 45 unsigned long sie_control_block; 46 unsigned long sie_savearea; 47 unsigned long sie_reason; 48 unsigned long sie_flags; 49 unsigned long sie_control_block_phys; 50 }; 51 }; 52 unsigned long gprs[10]; 53 unsigned long back_chain; 54 }; 55 56 /* 57 * Unlike current_stack_pointer which simply contains the current value of %r15 58 * current_frame_address() returns function stack frame address, which matches 59 * %r15 upon function invocation. It may differ from %r15 later if function 60 * allocates stack for local variables or new stack frame to call other 61 * functions. 62 */ 63 #define current_frame_address() \ 64 ((unsigned long)__builtin_frame_address(0) - \ 65 offsetof(struct stack_frame, back_chain)) 66 67 static __always_inline unsigned long get_stack_pointer(struct task_struct *task, 68 struct pt_regs *regs) 69 { 70 if (regs) 71 return (unsigned long)kernel_stack_pointer(regs); 72 if (task == current) 73 return current_frame_address(); 74 return (unsigned long)task->thread.ksp; 75 } 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 /* 193 * Use call_nodat() to call a function with DAT disabled. 194 * Proper sign and zero extension of function arguments is done. 195 * Usage: 196 * 197 * rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...) 198 * 199 * - nr specifies the number of function arguments of fn. 200 * - fn is the function to be called, where fn is a physical address. 201 * - rettype is the return type of fn. 202 * - t1, a1, ... are pairs, where t1 must match the type of the first 203 * argument of fn, t2 the second, etc. a1 is the corresponding 204 * first function argument (not name), etc. 205 * 206 * fn() is called with standard C function call ABI, with the exception 207 * that no useful stackframe or stackpointer is passed via register 15. 208 * Therefore the called function must not use r15 to access the stack. 209 */ 210 #define call_nodat(nr, rettype, fn, ...) \ 211 ({ \ 212 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn); \ 213 /* aligned since psw_leave must not cross page boundary */ \ 214 psw_t __aligned(16) psw_leave; \ 215 psw_t psw_enter; \ 216 CALL_LARGS_##nr(__VA_ARGS__); \ 217 CALL_REGS_##nr; \ 218 \ 219 CALL_TYPECHECK_##nr(__VA_ARGS__); \ 220 psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT; \ 221 psw_enter.addr = (unsigned long)__fn; \ 222 asm volatile( \ 223 " epsw 0,1\n" \ 224 " risbg 1,0,0,31,32\n" \ 225 " larl 7,1f\n" \ 226 " stg 1,%[psw_leave]\n" \ 227 " stg 7,8+%[psw_leave]\n" \ 228 " la 7,%[psw_leave]\n" \ 229 " lra 7,0(7)\n" \ 230 " larl 1,0f\n" \ 231 " lra 14,0(1)\n" \ 232 " lpswe %[psw_enter]\n" \ 233 "0: lpswe 0(7)\n" \ 234 "1:\n" \ 235 : CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave) \ 236 : [psw_enter] "Q" (psw_enter) \ 237 : "7", CALL_CLOBBER_##nr); \ 238 (rettype)r2; \ 239 }) 240 241 #endif /* _ASM_S390_STACKTRACE_H */ 242