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 static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
  38                                                        struct pt_regs *regs)
  39 {
  40         if (regs)
  41                 return (unsigned long) kernel_stack_pointer(regs);
  42         if (task == current)
  43                 return current_stack_pointer();
  44         return (unsigned long) task->thread.ksp;
  45 }
  46
  47 /*
  48  * Stack layout of a C stack frame.
  49  */
  50 #ifndef __PACK_STACK
  51 struct stack_frame {
  52         unsigned long back_chain;
  53         unsigned long empty1[5];
  54         unsigned long gprs[10];
  55         unsigned int  empty2[8];
  56 };
  57 #else
  58 struct stack_frame {
  59         unsigned long empty1[5];
  60         unsigned int  empty2[8];
  61         unsigned long gprs[10];
  62         unsigned long back_chain;
  63 };
  64 #endif
  65
  66 /*
  67  * Unlike current_stack_pointer() which simply returns current value of %r15
  68  * current_frame_address() returns function stack frame address, which matches
  69  * %r15 upon function invocation. It may differ from %r15 later if function
  70  * allocates stack for local variables or new stack frame to call other
  71  * functions.
  72  */
  73 #define current_frame_address()                                         \
  74         ((unsigned long)__builtin_frame_address(0) -                    \
  75          offsetof(struct stack_frame, back_chain))
  76
  77 #define CALL_ARGS_0()                                                   \
  78         register unsigned long r2 asm("2")
  79 #define CALL_ARGS_1(arg1)                                               \
  80         register unsigned long r2 asm("2") = (unsigned long)(arg1)
  81 #define CALL_ARGS_2(arg1, arg2)                                         \
  82         CALL_ARGS_1(arg1);                                              \
  83         register unsigned long r3 asm("3") = (unsigned long)(arg2)
  84 #define CALL_ARGS_3(arg1, arg2, arg3)                                   \
  85         CALL_ARGS_2(arg1, arg2);                                        \
  86         register unsigned long r4 asm("4") = (unsigned long)(arg3)
  87 #define CALL_ARGS_4(arg1, arg2, arg3, arg4)                             \
  88         CALL_ARGS_3(arg1, arg2, arg3);                                  \
  89         register unsigned long r4 asm("5") = (unsigned long)(arg4)
  90 #define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5)                       \
  91         CALL_ARGS_4(arg1, arg2, arg3, arg4);                            \
  92         register unsigned long r4 asm("6") = (unsigned long)(arg5)
  93
  94 /*
  95  * To keep this simple mark register 2-6 as being changed (volatile)
  96  * by the called function, even though register 6 is saved/nonvolatile.
  97  */
  98 #define CALL_FMT_0 "=&d" (r2)
  99 #define CALL_FMT_1 "+&d" (r2)
 100 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
 101 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
 102 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
 103 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
 104
 105 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
 106 #define CALL_CLOBBER_4 CALL_CLOBBER_5
 107 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
 108 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
 109 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
 110 #define CALL_CLOBBER_0 CALL_CLOBBER_1
 111
 112 #define CALL_ON_STACK(fn, stack, nr, args...)                           \
 113 ({                                                                      \
 114         unsigned long frame = current_frame_address();                  \
 115         CALL_ARGS_##nr(args);                                           \
 116         unsigned long prev;                                             \
 117                                                                         \
 118         asm volatile(                                                   \
 119                 "       la      %[_prev],0(15)\n"                       \
 120                 "       lg      15,%[_stack]\n"                         \
 121                 "       stg     %[_frame],%[_bc](15)\n"                 \
 122                 "       brasl   14,%[_fn]\n"                            \
 123                 "       la      15,0(%[_prev])\n"                       \
 124                 : [_prev] "=&a" (prev), CALL_FMT_##nr                   \
 125                 : [_stack] "R" (stack),                                 \
 126                   [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 127                   [_frame] "d" (frame),                                 \
 128                   [_fn] "X" (fn) : CALL_CLOBBER_##nr);                  \
 129         r2;                                                             \
 130 })
 131
 132 #define CALL_ON_STACK_NORETURN(fn, stack)                               \
 133 ({                                                                      \
 134         asm volatile(                                                   \
 135                 "       la      15,0(%[_stack])\n"                      \
 136                 "       xc      %[_bc](8,15),%[_bc](15)\n"              \
 137                 "       brasl   14,%[_fn]\n"                            \
 138                 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 139                   [_stack] "a" (stack), [_fn] "X" (fn));                \
 140         BUG();                                                          \
 141 })
 142
 143 #endif /* _ASM_S390_STACKTRACE_H */