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 };
  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 __always_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 /*
  66  * Unlike current_stack_pointer() which simply returns current value of %r15
  67  * current_frame_address() returns function stack frame address, which matches
  68  * %r15 upon function invocation. It may differ from %r15 later if function
  69  * allocates stack for local variables or new stack frame to call other
  70  * functions.
  71  */
  72 #define current_frame_address()                                         \
  73         ((unsigned long)__builtin_frame_address(0) -                    \
  74          offsetof(struct stack_frame, back_chain))
  75
  76 #define CALL_ARGS_0()                                                   \
  77         register unsigned long r2 asm("2")
  78 #define CALL_ARGS_1(arg1)                                               \
  79         register unsigned long r2 asm("2") = (unsigned long)(arg1)
  80 #define CALL_ARGS_2(arg1, arg2)                                         \
  81         CALL_ARGS_1(arg1);                                              \
  82         register unsigned long r3 asm("3") = (unsigned long)(arg2)
  83 #define CALL_ARGS_3(arg1, arg2, arg3)                                   \
  84         CALL_ARGS_2(arg1, arg2);                                        \
  85         register unsigned long r4 asm("4") = (unsigned long)(arg3)
  86 #define CALL_ARGS_4(arg1, arg2, arg3, arg4)                             \
  87         CALL_ARGS_3(arg1, arg2, arg3);                                  \
  88         register unsigned long r4 asm("5") = (unsigned long)(arg4)
  89 #define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5)                       \
  90         CALL_ARGS_4(arg1, arg2, arg3, arg4);                            \
  91         register unsigned long r4 asm("6") = (unsigned long)(arg5)
  92
  93 #define CALL_FMT_0 "=&d" (r2) :
  94 #define CALL_FMT_1 "+&d" (r2) :
  95 #define CALL_FMT_2 CALL_FMT_1 "d" (r3),
  96 #define CALL_FMT_3 CALL_FMT_2 "d" (r4),
  97 #define CALL_FMT_4 CALL_FMT_3 "d" (r5),
  98 #define CALL_FMT_5 CALL_FMT_4 "d" (r6),
  99
 100 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
 101 #define CALL_CLOBBER_4 CALL_CLOBBER_5
 102 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
 103 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
 104 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
 105 #define CALL_CLOBBER_0 CALL_CLOBBER_1
 106
 107 #define CALL_ON_STACK(fn, stack, nr, args...)                           \
 108 ({                                                                      \
 109         unsigned long frame = current_frame_address();                  \
 110         CALL_ARGS_##nr(args);                                           \
 111         unsigned long prev;                                             \
 112                                                                         \
 113         asm volatile(                                                   \
 114                 "       la      %[_prev],0(15)\n"                       \
 115                 "       lg      15,%[_stack]\n"                         \
 116                 "       stg     %[_frame],%[_bc](15)\n"                 \
 117                 "       brasl   14,%[_fn]\n"                            \
 118                 "       la      15,0(%[_prev])\n"                       \
 119                 : [_prev] "=&a" (prev), CALL_FMT_##nr                   \
 120                   [_stack] "R" (stack),                                 \
 121                   [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 122                   [_frame] "d" (frame),                                 \
 123                   [_fn] "X" (fn) : CALL_CLOBBER_##nr);                  \
 124         r2;                                                             \
 125 })
 126
 127 #define CALL_ON_STACK_NORETURN(fn, stack)                               \
 128 ({                                                                      \
 129         asm volatile(                                                   \
 130                 "       la      15,0(%[_stack])\n"                      \
 131                 "       xc      %[_bc](8,15),%[_bc](15)\n"              \
 132                 "       brasl   14,%[_fn]\n"                            \
 133                 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
 134                   [_stack] "a" (stack), [_fn] "X" (fn));                \
 135         BUG();                                                          \
 136 })
 137
 138 #endif /* _ASM_S390_STACKTRACE_H */