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