LXR linux/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
   9enum 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
  18struct stack_info {
  19        enum stack_type type;
  20        unsigned long begin, end;
  21};
  22
  23const char *stack_type_name(enum stack_type type);
  24int get_stack_info(unsigned long sp, struct task_struct *task,
  25                   struct stack_info *info, unsigned long *visit_mask);
  26
  27static 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
  41struct 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
  48struct 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
  67static __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 */
 206