arch/s390/include/asm/stacktrace.h

   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 */