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 /* SIE stack frame */ 63 struct { 64 unsigned long sie_control_block; 65 unsigned long sie_savearea; 66 unsigned long sie_return; 67 unsigned long sie_flags; 68 unsigned long sie_control_block_phys; 69 unsigned long sie_guest_asce; 70 unsigned long sie_irq; 71 }; 72 /* SAE stack frame */ 73 struct { 74 unsigned long sae_bear; 75 }; 76 }; 77 unsigned long gprs[10]; 78 unsigned long back_chain; 79 }; 80 81 /* 82 * Unlike current_stack_pointer which simply contains the current value of %r15 83 * current_frame_address() returns function stack frame address, which matches 84 * %r15 upon function invocation. It may differ from %r15 later if function 85 * allocates stack for local variables or new stack frame to call other 86 * functions. 87 */ 88 #define current_frame_address() \ 89 ((unsigned long)__builtin_frame_address(0) - \ 90 offsetof(struct stack_frame, back_chain)) 91 92 static __always_inline unsigned long get_stack_pointer(struct task_struct *task, 93 struct pt_regs *regs) 94 { 95 if (regs) 96 return (unsigned long)kernel_stack_pointer(regs); 97 if (task == current) 98 return current_frame_address(); 99 return (unsigned long)task->thread.ksp; 100 } 101 102 /* 103 * To keep this simple mark register 2-6 as being changed (volatile) 104 * by the called function, even though register 6 is saved/nonvolatile. 105 */ 106 #define CALL_FMT_0 "=&d" (r2) 107 #define CALL_FMT_1 "+&d" (r2) 108 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3) 109 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4) 110 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5) 111 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6) 112 113 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" 114 #define CALL_CLOBBER_4 CALL_CLOBBER_5 115 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" 116 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" 117 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" 118 #define CALL_CLOBBER_0 CALL_CLOBBER_1 119 120 #define CALL_LARGS_0(...) \ 121 long dummy = 0 122 #define CALL_LARGS_1(t1, a1) \ 123 long arg1 = (long)(t1)(a1) 124 #define CALL_LARGS_2(t1, a1, t2, a2) \ 125 CALL_LARGS_1(t1, a1); \ 126 long arg2 = (long)(t2)(a2) 127 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \ 128 CALL_LARGS_2(t1, a1, t2, a2); \ 129 long arg3 = (long)(t3)(a3) 130 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \ 131 CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \ 132 long arg4 = (long)(t4)(a4) 133 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \ 134 CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \ 135 long arg5 = (long)(t5)(a5) 136 137 #define CALL_REGS_0 \ 138 register long r2 asm("2") = dummy 139 #define CALL_REGS_1 \ 140 register long r2 asm("2") = arg1 141 #define CALL_REGS_2 \ 142 CALL_REGS_1; \ 143 register long r3 asm("3") = arg2 144 #define CALL_REGS_3 \ 145 CALL_REGS_2; \ 146 register long r4 asm("4") = arg3 147 #define CALL_REGS_4 \ 148 CALL_REGS_3; \ 149 register long r5 asm("5") = arg4 150 #define CALL_REGS_5 \ 151 CALL_REGS_4; \ 152 register long r6 asm("6") = arg5 153 154 #define CALL_TYPECHECK_0(...) 155 #define CALL_TYPECHECK_1(t, a, ...) \ 156 typecheck(t, a) 157 #define CALL_TYPECHECK_2(t, a, ...) \ 158 CALL_TYPECHECK_1(__VA_ARGS__); \ 159 typecheck(t, a) 160 #define CALL_TYPECHECK_3(t, a, ...) \ 161 CALL_TYPECHECK_2(__VA_ARGS__); \ 162 typecheck(t, a) 163 #define CALL_TYPECHECK_4(t, a, ...) \ 164 CALL_TYPECHECK_3(__VA_ARGS__); \ 165 typecheck(t, a) 166 #define CALL_TYPECHECK_5(t, a, ...) \ 167 CALL_TYPECHECK_4(__VA_ARGS__); \ 168 typecheck(t, a) 169 170 #define CALL_PARM_0(...) void 171 #define CALL_PARM_1(t, a, ...) t 172 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__) 173 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__) 174 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__) 175 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__) 176 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__) 177 178 /* 179 * Use call_on_stack() to call a function switching to a specified 180 * stack. Proper sign and zero extension of function arguments is 181 * done. Usage: 182 * 183 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...) 184 * 185 * - nr specifies the number of function arguments of fn. 186 * - stack specifies the stack to be used. 187 * - fn is the function to be called. 188 * - rettype is the return type of fn. 189 * - t1, a1, ... are pairs, where t1 must match the type of the first 190 * argument of fn, t2 the second, etc. a1 is the corresponding 191 * first function argument (not name), etc. 192 */ 193 #define call_on_stack(nr, stack, rettype, fn, ...) \ 194 ({ \ 195 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \ 196 unsigned long frame = current_frame_address(); \ 197 unsigned long __stack = stack; \ 198 unsigned long prev; \ 199 CALL_LARGS_##nr(__VA_ARGS__); \ 200 CALL_REGS_##nr; \ 201 \ 202 CALL_TYPECHECK_##nr(__VA_ARGS__); \ 203 asm volatile( \ 204 " lgr %[_prev],15\n" \ 205 " lg 15,%[_stack]\n" \ 206 " stg %[_frame],%[_bc](15)\n" \ 207 " brasl 14,%[_fn]\n" \ 208 " lgr 15,%[_prev]" \ 209 : [_prev] "=&d" (prev), CALL_FMT_##nr \ 210 : [_stack] "R" (__stack), \ 211 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ 212 [_frame] "d" (frame), \ 213 [_fn] "X" (__fn) : CALL_CLOBBER_##nr); \ 214 (rettype)r2; \ 215 }) 216 217 /* 218 * Use call_nodat() to call a function with DAT disabled. 219 * Proper sign and zero extension of function arguments is done. 220 * Usage: 221 * 222 * rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...) 223 * 224 * - nr specifies the number of function arguments of fn. 225 * - fn is the function to be called, where fn is a physical address. 226 * - rettype is the return type of fn. 227 * - t1, a1, ... are pairs, where t1 must match the type of the first 228 * argument of fn, t2 the second, etc. a1 is the corresponding 229 * first function argument (not name), etc. 230 * 231 * fn() is called with standard C function call ABI, with the exception 232 * that no useful stackframe or stackpointer is passed via register 15. 233 * Therefore the called function must not use r15 to access the stack. 234 */ 235 #define call_nodat(nr, rettype, fn, ...) \ 236 ({ \ 237 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn); \ 238 /* aligned since psw_leave must not cross page boundary */ \ 239 psw_t __aligned(16) psw_leave; \ 240 psw_t psw_enter; \ 241 CALL_LARGS_##nr(__VA_ARGS__); \ 242 CALL_REGS_##nr; \ 243 \ 244 CALL_TYPECHECK_##nr(__VA_ARGS__); \ 245 psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT; \ 246 psw_enter.addr = (unsigned long)__fn; \ 247 asm volatile( \ 248 " epsw 0,1\n" \ 249 " risbg 1,0,0,31,32\n" \ 250 " larl 7,1f\n" \ 251 " stg 1,%[psw_leave]\n" \ 252 " stg 7,8+%[psw_leave]\n" \ 253 " la 7,%[psw_leave]\n" \ 254 " lra 7,0(7)\n" \ 255 " larl 1,0f\n" \ 256 " lra 14,0(1)\n" \ 257 " lpswe %[psw_enter]\n" \ 258 "0: lpswe 0(7)\n" \ 259 "1:" \ 260 : CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave) \ 261 : [psw_enter] "Q" (psw_enter) \ 262 : "7", CALL_CLOBBER_##nr); \ 263 (rettype)r2; \ 264 }) 265 266 #endif /* _ASM_S390_STACKTRACE_H */ 267