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/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 };
  16
  17 struct stack_info {
  18         enum stack_type type;
  19         unsigned long begin, end;
  20 };
  21
  22 const char *stack_type_name(enum stack_type type);
  23 int get_stack_info(unsigned long sp, struct task_struct *task,
  24                    struct stack_info *info, unsigned long *visit_mask);
  25
  26 static inline bool on_stack(struct stack_info *info,
  27                             unsigned long addr, size_t len)
  28 {
  29         if (info->type == STACK_TYPE_UNKNOWN)
  30                 return false;
  31         if (addr + len < addr)
  32                 return false;
  33         return addr >= info->begin && addr + len <= info->end;
  34 }
  35
  36 static inline unsigned long get_stack_pointer(struct task_struct *task,
  37                                               struct pt_regs *regs)
  38 {
  39         if (regs)
  40                 return (unsigned long) kernel_stack_pointer(regs);
  41         if (task == current)
  42                 return current_stack_pointer();
  43         return (unsigned long) task->thread.ksp;
  44 }
  45
  46 /*
  47  * Stack layout of a C stack frame.
  48  */
  49 #ifndef __PACK_STACK
  50 struct stack_frame {
  51         unsigned long back_chain;
  52         unsigned long empty1[5];
  53         unsigned long gprs[10];
  54         unsigned int  empty2[8];
  55 };
  56 #else
  57 struct stack_frame {
  58         unsigned long empty1[5];
  59         unsigned int  empty2[8];
  60         unsigned long gprs[10];
  61         unsigned long back_chain;
  62 };
  63 #endif
  64
  65 #define CALL_ARGS_0()                                                   \
  66         register unsigned long r2 asm("2")
  67 #define CALL_ARGS_1(arg1)                                               \
  68         register unsigned long r2 asm("2") = (unsigned long)(arg1)
  69 #define CALL_ARGS_2(arg1, arg2)                                         \
  70         CALL_ARGS_1(arg1);                                              \
  71         register unsigned long r3 asm("3") = (unsigned long)(arg2)
  72 #define CALL_ARGS_3(arg1, arg2, arg3)                                   \
  73         CALL_ARGS_2(arg1, arg2);                                        \
  74         register unsigned long r4 asm("4") = (unsigned long)(arg3)
  75 #define CALL_ARGS_4(arg1, arg2, arg3, arg4)                             \
  76         CALL_ARGS_3(arg1, arg2, arg3);                                  \
  77         register unsigned long r4 asm("5") = (unsigned long)(arg4)
  78 #define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5)                       \
  79         CALL_ARGS_4(arg1, arg2, arg3, arg4);                            \
  80         register unsigned long r4 asm("6") = (unsigned long)(arg5)
  81
  82 /*
  83  * To keep this simple mark register 2-6 as being changed (volatile)
  84  * by the called function, even though register 6 is saved/nonvolatile.
  85  */
  86 #define CALL_FMT_0 "=&d" (r2)
  87 #define CALL_FMT_1 "+&d" (r2)
  88 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
  89 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
  90 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
  91 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
  92
  93 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
  94 #define CALL_CLOBBER_4 CALL_CLOBBER_5
  95 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
  96 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
  97 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
  98 #define CALL_CLOBBER_0 CALL_CLOBBER_1
  99
 100 #define CALL_ON_STACK(fn, stack, nr, args...)                           \
 101 ({                                                                      \
 102         CALL_ARGS_##nr(args);                                           \
 103         unsigned long prev;                                             \
 104                                                                         \
 105         asm volatile(                                                   \
 106                 "       la      %[_prev],0(15)\n"                       \
 107                 "       la      15,0(%[_stack])\n"                      \
 108                 "       stg     %[_prev],%[_bc](15)\n"                  \
 109                 "       brasl   14,%[_fn]\n"                            \
 110                 "       la      15,0(%[_prev])\n"                       \
 111                 : [_prev] "=&a" (prev), CALL_FMT_##nr                   \
 112                 : [_stack] "a" (stack),                                 \
 113                   [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 114                   [_fn] "X" (fn) : CALL_CLOBBER_##nr);                  \
 115         r2;                                                             \
 116 })
 117
 118 #define CALL_LARGS_0(...)                                               \
 119         long dummy = 0
 120 #define CALL_LARGS_1(t1, a1)                                            \
 121         long arg1  = (long)(t1)(a1)
 122 #define CALL_LARGS_2(t1, a1, t2, a2)                                    \
 123         CALL_LARGS_1(t1, a1);                                           \
 124         long arg2 = (long)(t2)(a2)
 125 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3)                            \
 126         CALL_LARGS_2(t1, a1, t2, a2);                                   \
 127         long arg3 = (long)(t3)(a3)
 128 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4)                    \
 129         CALL_LARGS_3(t1, a1, t2, a2, t3, a3);                           \
 130         long arg4  = (long)(t4)(a4)
 131 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5)            \
 132         CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4);                   \
 133         long arg5 = (long)(t5)(a5)
 134
 135 #define CALL_REGS_0                                                     \
 136         register long r2 asm("2") = dummy
 137 #define CALL_REGS_1                                                     \
 138         register long r2 asm("2") = arg1
 139 #define CALL_REGS_2                                                     \
 140         CALL_REGS_1;                                                    \
 141         register long r3 asm("3") = arg2
 142 #define CALL_REGS_3                                                     \
 143         CALL_REGS_2;                                                    \
 144         register long r4 asm("4") = arg3
 145 #define CALL_REGS_4                                                     \
 146         CALL_REGS_3;                                                    \
 147         register long r5 asm("5") = arg4
 148 #define CALL_REGS_5                                                     \
 149         CALL_REGS_4;                                                    \
 150         register long r6 asm("6") = arg5
 151
 152 #define CALL_TYPECHECK_0(...)
 153 #define CALL_TYPECHECK_1(t, a, ...)                                     \
 154         typecheck(t, a)
 155 #define CALL_TYPECHECK_2(t, a, ...)                                     \
 156         CALL_TYPECHECK_1(__VA_ARGS__);                                  \
 157         typecheck(t, a)
 158 #define CALL_TYPECHECK_3(t, a, ...)                                     \
 159         CALL_TYPECHECK_2(__VA_ARGS__);                                  \
 160         typecheck(t, a)
 161 #define CALL_TYPECHECK_4(t, a, ...)                                     \
 162         CALL_TYPECHECK_3(__VA_ARGS__);                                  \
 163         typecheck(t, a)
 164 #define CALL_TYPECHECK_5(t, a, ...)                                     \
 165         CALL_TYPECHECK_4(__VA_ARGS__);                                  \
 166         typecheck(t, a)
 167
 168 #define CALL_PARM_0(...) void
 169 #define CALL_PARM_1(t, a, ...) t
 170 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
 171 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
 172 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
 173 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
 174 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
 175
 176 /*
 177  * Use call_on_stack() to call a function switching to a specified
 178  * stack. Proper sign and zero extension of function arguments is
 179  * done. Usage:
 180  *
 181  * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
 182  *
 183  * - nr specifies the number of function arguments of fn.
 184  * - stack specifies the stack to be used.
 185  * - fn is the function to be called.
 186  * - rettype is the return type of fn.
 187  * - t1, a1, ... are pairs, where t1 must match the type of the first
 188  *   argument of fn, t2 the second, etc. a1 is the corresponding
 189  *   first function argument (not name), etc.
 190  */
 191 #define call_on_stack(nr, stack, rettype, fn, ...)                      \
 192 ({                                                                      \
 193         rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn;              \
 194         unsigned long frame = current_frame_address();                  \
 195         unsigned long __stack = stack;                                  \
 196         unsigned long prev;                                             \
 197         CALL_LARGS_##nr(__VA_ARGS__);                                   \
 198         CALL_REGS_##nr;                                                 \
 199                                                                         \
 200         CALL_TYPECHECK_##nr(__VA_ARGS__);                               \
 201         asm volatile(                                                   \
 202                 "       lgr     %[_prev],15\n"                          \
 203                 "       lg      15,%[_stack]\n"                         \
 204                 "       stg     %[_frame],%[_bc](15)\n"                 \
 205                 "       brasl   14,%[_fn]\n"                            \
 206                 "       lgr     15,%[_prev]\n"                          \
 207                 : [_prev] "=&d" (prev), CALL_FMT_##nr                   \
 208                 : [_stack] "R" (__stack),                               \
 209                   [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 210                   [_frame] "d" (frame),                                 \
 211                   [_fn] "X" (__fn) : CALL_CLOBBER_##nr);                \
 212         (rettype)r2;                                                    \
 213 })
 214
 215 #define CALL_ON_STACK_NORETURN(fn, stack)                               \
 216 ({                                                                      \
 217         asm volatile(                                                   \
 218                 "       la      15,0(%[_stack])\n"                      \
 219                 "       xc      %[_bc](8,15),%[_bc](15)\n"              \
 220                 "       brasl   14,%[_fn]\n"                            \
 221                 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 222                   [_stack] "a" (stack), [_fn] "X" (fn));                \
 223         BUG();                                                          \
 224 })
 225
 226 #endif /* _ASM_S390_STACKTRACE_H */