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/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  */
  40 #ifndef __PACK_STACK
  41 struct stack_frame {
  42         unsigned long back_chain;
  43         unsigned long empty1[5];
  44         unsigned long gprs[10];
  45         unsigned int  empty2[8];
  46 };
  47 #else
  48 struct stack_frame {
  49         unsigned long empty1[5];
  50         unsigned int  empty2[8];
  51         unsigned long gprs[10];
  52         unsigned long back_chain;
  53 };
  54 #endif
  55
  56 /*
  57  * Unlike current_stack_pointer() which simply returns current value of %r15
  58  * current_frame_address() returns function stack frame address, which matches
  59  * %r15 upon function invocation. It may differ from %r15 later if function
  60  * allocates stack for local variables or new stack frame to call other
  61  * functions.
  62  */
  63 #define current_frame_address()                                         \
  64         ((unsigned long)__builtin_frame_address(0) -                    \
  65          offsetof(struct stack_frame, back_chain))
  66
  67 static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
  68                                                        struct pt_regs *regs)
  69 {
  70         if (regs)
  71                 return (unsigned long)kernel_stack_pointer(regs);
  72         if (task == current)
  73                 return current_frame_address();
  74         return (unsigned long)task->thread.ksp;
  75 }
  76
  77 /*
  78  * To keep this simple mark register 2-6 as being changed (volatile)
  79  * by the called function, even though register 6 is saved/nonvolatile.
  80  */
  81 #define CALL_FMT_0 "=&d" (r2)
  82 #define CALL_FMT_1 "+&d" (r2)
  83 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
  84 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
  85 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
  86 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
  87
  88 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
  89 #define CALL_CLOBBER_4 CALL_CLOBBER_5
  90 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
  91 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
  92 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
  93 #define CALL_CLOBBER_0 CALL_CLOBBER_1
  94
  95 #define CALL_LARGS_0(...)                                               \
  96         long dummy = 0
  97 #define CALL_LARGS_1(t1, a1)                                            \
  98         long arg1  = (long)(t1)(a1)
  99 #define CALL_LARGS_2(t1, a1, t2, a2)                                    \
 100         CALL_LARGS_1(t1, a1);                                           \
 101         long arg2 = (long)(t2)(a2)
 102 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3)                            \
 103         CALL_LARGS_2(t1, a1, t2, a2);                                   \
 104         long arg3 = (long)(t3)(a3)
 105 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4)                    \
 106         CALL_LARGS_3(t1, a1, t2, a2, t3, a3);                           \
 107         long arg4  = (long)(t4)(a4)
 108 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5)            \
 109         CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4);                   \
 110         long arg5 = (long)(t5)(a5)
 111
 112 #define CALL_REGS_0                                                     \
 113         register long r2 asm("2") = dummy
 114 #define CALL_REGS_1                                                     \
 115         register long r2 asm("2") = arg1
 116 #define CALL_REGS_2                                                     \
 117         CALL_REGS_1;                                                    \
 118         register long r3 asm("3") = arg2
 119 #define CALL_REGS_3                                                     \
 120         CALL_REGS_2;                                                    \
 121         register long r4 asm("4") = arg3
 122 #define CALL_REGS_4                                                     \
 123         CALL_REGS_3;                                                    \
 124         register long r5 asm("5") = arg4
 125 #define CALL_REGS_5                                                     \
 126         CALL_REGS_4;                                                    \
 127         register long r6 asm("6") = arg5
 128
 129 #define CALL_TYPECHECK_0(...)
 130 #define CALL_TYPECHECK_1(t, a, ...)                                     \
 131         typecheck(t, a)
 132 #define CALL_TYPECHECK_2(t, a, ...)                                     \
 133         CALL_TYPECHECK_1(__VA_ARGS__);                                  \
 134         typecheck(t, a)
 135 #define CALL_TYPECHECK_3(t, a, ...)                                     \
 136         CALL_TYPECHECK_2(__VA_ARGS__);                                  \
 137         typecheck(t, a)
 138 #define CALL_TYPECHECK_4(t, a, ...)                                     \
 139         CALL_TYPECHECK_3(__VA_ARGS__);                                  \
 140         typecheck(t, a)
 141 #define CALL_TYPECHECK_5(t, a, ...)                                     \
 142         CALL_TYPECHECK_4(__VA_ARGS__);                                  \
 143         typecheck(t, a)
 144
 145 #define CALL_PARM_0(...) void
 146 #define CALL_PARM_1(t, a, ...) t
 147 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
 148 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
 149 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
 150 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
 151 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
 152
 153 /*
 154  * Use call_on_stack() to call a function switching to a specified
 155  * stack. Proper sign and zero extension of function arguments is
 156  * done. Usage:
 157  *
 158  * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
 159  *
 160  * - nr specifies the number of function arguments of fn.
 161  * - stack specifies the stack to be used.
 162  * - fn is the function to be called.
 163  * - rettype is the return type of fn.
 164  * - t1, a1, ... are pairs, where t1 must match the type of the first
 165  *   argument of fn, t2 the second, etc. a1 is the corresponding
 166  *   first function argument (not name), etc.
 167  */
 168 #define call_on_stack(nr, stack, rettype, fn, ...)                      \
 169 ({                                                                      \
 170         rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn;              \
 171         unsigned long frame = current_frame_address();                  \
 172         unsigned long __stack = stack;                                  \
 173         unsigned long prev;                                             \
 174         CALL_LARGS_##nr(__VA_ARGS__);                                   \
 175         CALL_REGS_##nr;                                                 \
 176                                                                         \
 177         CALL_TYPECHECK_##nr(__VA_ARGS__);                               \
 178         asm volatile(                                                   \
 179                 "       lgr     %[_prev],15\n"                          \
 180                 "       lg      15,%[_stack]\n"                         \
 181                 "       stg     %[_frame],%[_bc](15)\n"                 \
 182                 "       brasl   14,%[_fn]\n"                            \
 183                 "       lgr     15,%[_prev]\n"                          \
 184                 : [_prev] "=&d" (prev), CALL_FMT_##nr                   \
 185                 : [_stack] "R" (__stack),                               \
 186                   [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 187                   [_frame] "d" (frame),                                 \
 188                   [_fn] "X" (__fn) : CALL_CLOBBER_##nr);                \
 189         (rettype)r2;                                                    \
 190 })
 191
 192 #define call_on_stack_noreturn(fn, stack)                               \
 193 ({                                                                      \
 194         void (*__fn)(void) = fn;                                        \
 195                                                                         \
 196         asm volatile(                                                   \
 197                 "       la      15,0(%[_stack])\n"                      \
 198                 "       xc      %[_bc](8,15),%[_bc](15)\n"              \
 199                 "       brasl   14,%[_fn]\n"                            \
 200                 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 201                   [_stack] "a" (stack), [_fn] "X" (__fn));              \
 202         BUG();                                                          \
 203 })
 204
 205 #endif /* _ASM_S390_STACKTRACE_H */