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