diff options
Diffstat (limited to 'arch/s390/kernel/syscall.c')
| -rw-r--r-- | arch/s390/kernel/syscall.c | 51 |
1 files changed, 18 insertions, 33 deletions
diff --git a/arch/s390/kernel/syscall.c b/arch/s390/kernel/syscall.c index 5ec28028315b..4fee74553ca2 100644 --- a/arch/s390/kernel/syscall.c +++ b/arch/s390/kernel/syscall.c @@ -12,6 +12,7 @@ * platform. */ +#include <linux/cpufeature.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/mm.h> @@ -81,25 +82,35 @@ SYSCALL_DEFINE0(ni_syscall) return -ENOSYS; } -static void do_syscall(struct pt_regs *regs) +void noinstr __do_syscall(struct pt_regs *regs, int per_trap) { unsigned long nr; + add_random_kstack_offset(); + enter_from_user_mode(regs); + regs->psw = get_lowcore()->svc_old_psw; + regs->int_code = get_lowcore()->svc_int_code; + update_timer_sys(); + if (cpu_has_bear()) + current->thread.last_break = regs->last_break; + local_irq_enable(); + regs->orig_gpr2 = regs->gprs[2]; + if (unlikely(per_trap)) + set_thread_flag(TIF_PER_TRAP); + regs->flags = 0; + set_pt_regs_flag(regs, PIF_SYSCALL); nr = regs->int_code & 0xffff; - if (!nr) { + if (likely(!nr)) { nr = regs->gprs[1] & 0xffff; regs->int_code &= ~0xffffUL; regs->int_code |= nr; } - regs->gprs[2] = nr; - if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) { regs->psw.addr = current->restart_block.arch_data; current->restart_block.arch_data = 1; } nr = syscall_enter_from_user_mode_work(regs, nr); - /* * In the s390 ptrace ABI, both the syscall number and the return value * use gpr2. However, userspace puts the syscall number either in the @@ -107,37 +118,11 @@ static void do_syscall(struct pt_regs *regs) * work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here * and if set, the syscall will be skipped. */ - if (unlikely(test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET))) goto out; regs->gprs[2] = -ENOSYS; - if (likely(nr >= NR_syscalls)) - goto out; - do { + if (likely(nr < NR_syscalls)) regs->gprs[2] = current->thread.sys_call_table[nr](regs); - } while (test_and_clear_pt_regs_flag(regs, PIF_EXECVE_PGSTE_RESTART)); out: - syscall_exit_to_user_mode_work(regs); -} - -void noinstr __do_syscall(struct pt_regs *regs, int per_trap) -{ - add_random_kstack_offset(); - enter_from_user_mode(regs); - regs->psw = get_lowcore()->svc_old_psw; - regs->int_code = get_lowcore()->svc_int_code; - update_timer_sys(); - if (static_branch_likely(&cpu_has_bear)) - current->thread.last_break = regs->last_break; - - local_irq_enable(); - regs->orig_gpr2 = regs->gprs[2]; - - if (per_trap) - set_thread_flag(TIF_PER_TRAP); - - regs->flags = 0; - set_pt_regs_flag(regs, PIF_SYSCALL); - do_syscall(regs); - exit_to_user_mode(); + syscall_exit_to_user_mode(regs); } |