diff options
Diffstat (limited to 'arch/s390/kernel/vdso64/vdso_user_wrapper.S')
| -rw-r--r-- | arch/s390/kernel/vdso64/vdso_user_wrapper.S | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/vdso_user_wrapper.S b/arch/s390/kernel/vdso64/vdso_user_wrapper.S new file mode 100644 index 000000000000..57f62596e53b --- /dev/null +++ b/arch/s390/kernel/vdso64/vdso_user_wrapper.S @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> +#include <asm/vdso.h> +#include <asm/unistd.h> +#include <asm/asm-offsets.h> +#include <asm/dwarf.h> +#include <asm/ptrace.h> + +#define WRAPPER_FRAME_SIZE (STACK_FRAME_OVERHEAD+8) + +/* + * Older glibc version called vdso without allocating a stackframe. This wrapper + * is just used to allocate a stackframe. See + * https://sourceware.org/git/?p=glibc.git;a=commit;h=478593e6374f3818da39332260dc453cb19cfa1e + * for details. + */ +.macro vdso_func func + .globl __kernel_\func + .type __kernel_\func,@function + __ALIGN +__kernel_\func: + CFI_STARTPROC + aghi %r15,-WRAPPER_FRAME_SIZE + CFI_DEF_CFA_OFFSET (STACK_FRAME_OVERHEAD + WRAPPER_FRAME_SIZE) + CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD + stg %r14,STACK_FRAME_OVERHEAD(%r15) + brasl %r14,__s390_vdso_\func + lg %r14,STACK_FRAME_OVERHEAD(%r15) + aghi %r15,WRAPPER_FRAME_SIZE + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD + CFI_RESTORE 15 + br %r14 + CFI_ENDPROC + .size __kernel_\func,.-__kernel_\func +.endm + +vdso_func gettimeofday +vdso_func clock_getres +vdso_func clock_gettime +vdso_func getcpu + +.macro vdso_syscall func,syscall + .globl __kernel_\func + .type __kernel_\func,@function + __ALIGN +__kernel_\func: + CFI_STARTPROC + svc \syscall + /* Make sure we notice when a syscall returns, which shouldn't happen */ + .word 0 + CFI_ENDPROC + .size __kernel_\func,.-__kernel_\func +.endm + +vdso_syscall restart_syscall,__NR_restart_syscall +vdso_syscall sigreturn,__NR_sigreturn +vdso_syscall rt_sigreturn,__NR_rt_sigreturn |