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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_STACKTRACE_H
#define _ASM_S390_STACKTRACE_H
#include <linux/uaccess.h>
#include <linux/ptrace.h>
#include <asm/switch_to.h>
enum stack_type {
STACK_TYPE_UNKNOWN,
STACK_TYPE_TASK,
STACK_TYPE_IRQ,
STACK_TYPE_NODAT,
STACK_TYPE_RESTART,
STACK_TYPE_MCCK,
};
struct stack_info {
enum stack_type type;
unsigned long begin, end;
};
const char *stack_type_name(enum stack_type type);
int get_stack_info(unsigned long sp, struct task_struct *task,
struct stack_info *info, unsigned long *visit_mask);
static inline bool on_stack(struct stack_info *info,
unsigned long addr, size_t len)
{
if (info->type == STACK_TYPE_UNKNOWN)
return false;
if (addr + len < addr)
return false;
return addr >= info->begin && addr + len <= info->end;
}
/*
* Stack layout of a C stack frame.
* Kernel uses the packed stack layout (-mpacked-stack).
*/
struct stack_frame {
union {
unsigned long empty[9];
struct {
unsigned long sie_control_block;
unsigned long sie_savearea;
unsigned long sie_reason;
unsigned long sie_flags;
unsigned long sie_control_block_phys;
};
};
unsigned long gprs[10];
unsigned long back_chain;
};
/*
* Unlike current_stack_pointer which simply contains the current value of %r15
* current_frame_address() returns function stack frame address, which matches
* %r15 upon function invocation. It may differ from %r15 later if function
* allocates stack for local variables or new stack frame to call other
* functions.
*/
#define current_frame_address() \
((unsigned long)__builtin_frame_address(0) - \
offsetof(struct stack_frame, back_chain))
static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
struct pt_regs *regs)
{
if (regs)
return (unsigned long)kernel_stack_pointer(regs);
if (task == current)
return current_frame_address();
return (unsigned long)task->thread.ksp;
}
/*
* To keep this simple mark register 2-6 as being changed (volatile)
* by the called function, even though register 6 is saved/nonvolatile.
*/
#define CALL_FMT_0 "=&d" (r2)
#define CALL_FMT_1 "+&d" (r2)
#define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
#define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
#define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
#define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
#define CALL_CLOBBER_4 CALL_CLOBBER_5
#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
#define CALL_CLOBBER_0 CALL_CLOBBER_1
#define CALL_LARGS_0(...) \
long dummy = 0
#define CALL_LARGS_1(t1, a1) \
long arg1 = (long)(t1)(a1)
#define CALL_LARGS_2(t1, a1, t2, a2) \
CALL_LARGS_1(t1, a1); \
long arg2 = (long)(t2)(a2)
#define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \
CALL_LARGS_2(t1, a1, t2, a2); \
long arg3 = (long)(t3)(a3)
#define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \
CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \
long arg4 = (long)(t4)(a4)
#define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \
CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \
long arg5 = (long)(t5)(a5)
#define CALL_REGS_0 \
register long r2 asm("2") = dummy
#define CALL_REGS_1 \
register long r2 asm("2") = arg1
#define CALL_REGS_2 \
CALL_REGS_1; \
register long r3 asm("3") = arg2
#define CALL_REGS_3 \
CALL_REGS_2; \
register long r4 asm("4") = arg3
#define CALL_REGS_4 \
CALL_REGS_3; \
register long r5 asm("5") = arg4
#define CALL_REGS_5 \
CALL_REGS_4; \
register long r6 asm("6") = arg5
#define CALL_TYPECHECK_0(...)
#define CALL_TYPECHECK_1(t, a, ...) \
typecheck(t, a)
#define CALL_TYPECHECK_2(t, a, ...) \
CALL_TYPECHECK_1(__VA_ARGS__); \
typecheck(t, a)
#define CALL_TYPECHECK_3(t, a, ...) \
CALL_TYPECHECK_2(__VA_ARGS__); \
typecheck(t, a)
#define CALL_TYPECHECK_4(t, a, ...) \
CALL_TYPECHECK_3(__VA_ARGS__); \
typecheck(t, a)
#define CALL_TYPECHECK_5(t, a, ...) \
CALL_TYPECHECK_4(__VA_ARGS__); \
typecheck(t, a)
#define CALL_PARM_0(...) void
#define CALL_PARM_1(t, a, ...) t
#define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
#define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
#define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
#define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
#define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
/*
* Use call_on_stack() to call a function switching to a specified
* stack. Proper sign and zero extension of function arguments is
* done. Usage:
*
* rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
*
* - nr specifies the number of function arguments of fn.
* - stack specifies the stack to be used.
* - fn is the function to be called.
* - rettype is the return type of fn.
* - t1, a1, ... are pairs, where t1 must match the type of the first
* argument of fn, t2 the second, etc. a1 is the corresponding
* first function argument (not name), etc.
*/
#define call_on_stack(nr, stack, rettype, fn, ...) \
({ \
rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \
unsigned long frame = current_frame_address(); \
unsigned long __stack = stack; \
unsigned long prev; \
CALL_LARGS_##nr(__VA_ARGS__); \
CALL_REGS_##nr; \
\
CALL_TYPECHECK_##nr(__VA_ARGS__); \
asm volatile( \
" lgr %[_prev],15\n" \
" lg 15,%[_stack]\n" \
" stg %[_frame],%[_bc](15)\n" \
" brasl 14,%[_fn]\n" \
" lgr 15,%[_prev]\n" \
: [_prev] "=&d" (prev), CALL_FMT_##nr \
: [_stack] "R" (__stack), \
[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
[_frame] "d" (frame), \
[_fn] "X" (__fn) : CALL_CLOBBER_##nr); \
(rettype)r2; \
})
/*
* Use call_nodat() to call a function with DAT disabled.
* Proper sign and zero extension of function arguments is done.
* Usage:
*
* rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...)
*
* - nr specifies the number of function arguments of fn.
* - fn is the function to be called, where fn is a physical address.
* - rettype is the return type of fn.
* - t1, a1, ... are pairs, where t1 must match the type of the first
* argument of fn, t2 the second, etc. a1 is the corresponding
* first function argument (not name), etc.
*
* fn() is called with standard C function call ABI, with the exception
* that no useful stackframe or stackpointer is passed via register 15.
* Therefore the called function must not use r15 to access the stack.
*/
#define call_nodat(nr, rettype, fn, ...) \
({ \
rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn); \
/* aligned since psw_leave must not cross page boundary */ \
psw_t __aligned(16) psw_leave; \
psw_t psw_enter; \
CALL_LARGS_##nr(__VA_ARGS__); \
CALL_REGS_##nr; \
\
CALL_TYPECHECK_##nr(__VA_ARGS__); \
psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT; \
psw_enter.addr = (unsigned long)__fn; \
asm volatile( \
" epsw 0,1\n" \
" risbg 1,0,0,31,32\n" \
" larl 7,1f\n" \
" stg 1,%[psw_leave]\n" \
" stg 7,8+%[psw_leave]\n" \
" la 7,%[psw_leave]\n" \
" lra 7,0(7)\n" \
" larl 1,0f\n" \
" lra 14,0(1)\n" \
" lpswe %[psw_enter]\n" \
"0: lpswe 0(7)\n" \
"1:\n" \
: CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave) \
: [psw_enter] "Q" (psw_enter) \
: "7", CALL_CLOBBER_##nr); \
(rettype)r2; \
})
#endif /* _ASM_S390_STACKTRACE_H */
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