diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/include/asm/ptrace.h | 8 | ||||
| -rw-r--r-- | arch/s390/kernel/syscall.c | 27 |
2 files changed, 20 insertions, 15 deletions
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h index c7850d649373..808da21235ab 100644 --- a/arch/s390/include/asm/ptrace.h +++ b/arch/s390/include/asm/ptrace.h @@ -162,6 +162,14 @@ static inline int test_pt_regs_flag(struct pt_regs *regs, int flag) return !!(regs->flags & (1UL << flag)); } +static inline int test_and_clear_pt_regs_flag(struct pt_regs *regs, int flag) +{ + int ret = test_pt_regs_flag(regs, flag); + + clear_pt_regs_flag(regs, flag); + return ret; +} + /* * These are defined as per linux/ptrace.h, which see. */ diff --git a/arch/s390/kernel/syscall.c b/arch/s390/kernel/syscall.c index ec73d2c61e58..0322f00f84ac 100644 --- a/arch/s390/kernel/syscall.c +++ b/arch/s390/kernel/syscall.c @@ -134,13 +134,15 @@ 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 (!test_pt_regs_flag(regs, PIF_SYSCALL_RET_SET)) { - regs->gprs[2] = -ENOSYS; - if (likely(nr < NR_syscalls)) - regs->gprs[2] = current->thread.sys_call_table[nr](regs); - } else { - clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET); - } + 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 { + regs->gprs[2] = current->thread.sys_call_table[nr](regs); + } while (test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RESTART)); +out: syscall_exit_to_user_mode_work(regs); } @@ -158,13 +160,8 @@ void noinstr __do_syscall(struct pt_regs *regs, int per_trap) if (per_trap) set_thread_flag(TIF_PER_TRAP); - for (;;) { - regs->flags = 0; - set_pt_regs_flag(regs, PIF_SYSCALL); - do_syscall(regs); - if (!test_pt_regs_flag(regs, PIF_SYSCALL_RESTART)) - break; - local_irq_enable(); - } + regs->flags = 0; + set_pt_regs_flag(regs, PIF_SYSCALL); + do_syscall(regs); exit_to_user_mode(); } |