linux_dsm_epyc7002/arch/s390/include/asm/stacktrace.h
Vasily Gorbik 4ac24c092b s390: fix register clobbering in CALL_ON_STACK
CALL_ON_STACK defines and initializes register variables. Inline
assembly which follows might trigger compiler to generate memory access
for "stack" argument (e.g. in case of S390_lowcore.nodat_stack). This
memory access produces a function call under kasan with outline
instrumentation which clobbers registers.

Switch "stack" argument in CALL_ON_STACK helper to use memory reference
constraint and perform load instead.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30 10:52:47 +01:00

139 lines
3.9 KiB
C

/* 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,
};
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;
}
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_stack_pointer();
return (unsigned long) task->thread.ksp;
}
/*
* Stack layout of a C stack frame.
*/
#ifndef __PACK_STACK
struct stack_frame {
unsigned long back_chain;
unsigned long empty1[5];
unsigned long gprs[10];
unsigned int empty2[8];
};
#else
struct stack_frame {
unsigned long empty1[5];
unsigned int empty2[8];
unsigned long gprs[10];
unsigned long back_chain;
};
#endif
/*
* Unlike current_stack_pointer() which simply returns 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))
#define CALL_ARGS_0() \
register unsigned long r2 asm("2")
#define CALL_ARGS_1(arg1) \
register unsigned long r2 asm("2") = (unsigned long)(arg1)
#define CALL_ARGS_2(arg1, arg2) \
CALL_ARGS_1(arg1); \
register unsigned long r3 asm("3") = (unsigned long)(arg2)
#define CALL_ARGS_3(arg1, arg2, arg3) \
CALL_ARGS_2(arg1, arg2); \
register unsigned long r4 asm("4") = (unsigned long)(arg3)
#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \
CALL_ARGS_3(arg1, arg2, arg3); \
register unsigned long r4 asm("5") = (unsigned long)(arg4)
#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \
CALL_ARGS_4(arg1, arg2, arg3, arg4); \
register unsigned long r4 asm("6") = (unsigned long)(arg5)
#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_ON_STACK(fn, stack, nr, args...) \
({ \
unsigned long frame = current_frame_address(); \
CALL_ARGS_##nr(args); \
unsigned long prev; \
\
asm volatile( \
" la %[_prev],0(15)\n" \
" lg 15,%[_stack]\n" \
" stg %[_frame],%[_bc](15)\n" \
" brasl 14,%[_fn]\n" \
" la 15,0(%[_prev])\n" \
: [_prev] "=&a" (prev), CALL_FMT_##nr \
[_stack] "R" (stack), \
[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
[_frame] "d" (frame), \
[_fn] "X" (fn) : CALL_CLOBBER_##nr); \
r2; \
})
#define CALL_ON_STACK_NORETURN(fn, stack) \
({ \
asm volatile( \
" la 15,0(%[_stack])\n" \
" xc %[_bc](8,15),%[_bc](15)\n" \
" brasl 14,%[_fn]\n" \
::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
[_stack] "a" (stack), [_fn] "X" (fn)); \
BUG(); \
})
#endif /* _ASM_S390_STACKTRACE_H */