xref: /linux/arch/s390/kernel/vdso64/vdso_user_wrapper.S (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/linkage.h>
3#include <asm/vdso.h>
4#include <asm/unistd.h>
5#include <asm/asm-offsets.h>
6#include <asm/dwarf.h>
7#include <asm/ptrace.h>
8
9/*
10 * Older glibc version called vdso without allocating a stackframe. This wrapper
11 * is just used to allocate a stackframe. See
12 * https://sourceware.org/git/?p=glibc.git;a=commit;h=478593e6374f3818da39332260dc453cb19cfa1e
13 * for details.
14 */
15.macro vdso_func func
16SYM_FUNC_START(__kernel_\func)
17	CFI_STARTPROC
18	aghi	%r15,-STACK_FRAME_VDSO_OVERHEAD
19	CFI_DEF_CFA_OFFSET (STACK_FRAME_USER_OVERHEAD + STACK_FRAME_VDSO_OVERHEAD)
20	CFI_VAL_OFFSET 15,-STACK_FRAME_USER_OVERHEAD
21	stg	%r14,__SFVDSO_RETURN_ADDRESS(%r15)
22	CFI_REL_OFFSET 14,__SFVDSO_RETURN_ADDRESS
23	xc	__SFUSER_BACKCHAIN(8,%r15),__SFUSER_BACKCHAIN(%r15)
24	brasl	%r14,__s390_vdso_\func
25	lg	%r14,__SFVDSO_RETURN_ADDRESS(%r15)
26	CFI_RESTORE 14
27	aghi	%r15,STACK_FRAME_VDSO_OVERHEAD
28	CFI_DEF_CFA_OFFSET STACK_FRAME_USER_OVERHEAD
29	CFI_RESTORE 15
30	br	%r14
31	CFI_ENDPROC
32SYM_FUNC_END(__kernel_\func)
33.endm
34
35vdso_func gettimeofday
36vdso_func clock_getres
37vdso_func clock_gettime
38vdso_func getcpu
39
40.macro vdso_syscall func,syscall
41SYM_FUNC_START(__kernel_\func)
42	CFI_STARTPROC
43	svc	\syscall
44	/* Make sure we notice when a syscall returns, which shouldn't happen */
45	.word	0
46	CFI_ENDPROC
47SYM_FUNC_END(__kernel_\func)
48.endm
49
50vdso_syscall restart_syscall,__NR_restart_syscall
51vdso_syscall sigreturn,__NR_sigreturn
52vdso_syscall rt_sigreturn,__NR_rt_sigreturn
53