Add TIF_RESTORE_SIGMASK We need TIF_RESTORE_SIGMASK in order to support ppoll() and pselect() system calls. This patch originally came from Andi, and was based heavily on David Howells' implementation of same on i386. I fixed a typo which was causing do_signal() to use the wrong signal mask. Signed-off-by: David Woodhouse Signed-off-by: Andi Kleen --- arch/x86_64/ia32/ia32_signal.c | 28 +++++-------- arch/x86_64/kernel/signal.c | 82 ++++++++++++++++----------------------- include/asm-x86_64/signal.h | 4 - include/asm-x86_64/thread_info.h | 2 include/asm-x86_64/unistd.h | 1 5 files changed, 49 insertions(+), 68 deletions(-) Index: linux/arch/x86_64/ia32/ia32_signal.c =================================================================== --- linux.orig/arch/x86_64/ia32/ia32_signal.c +++ linux/arch/x86_64/ia32/ia32_signal.c @@ -113,25 +113,19 @@ int copy_siginfo_from_user32(siginfo_t * } asmlinkage long -sys32_sigsuspend(int history0, int history1, old_sigset_t mask, - struct pt_regs *regs) +sys32_sigsuspend(int history0, int history1, old_sigset_t mask) { - sigset_t saveset; - mask &= _BLOCKABLE; spin_lock_irq(¤t->sighand->siglock); - saveset = current->blocked; + current->saved_sigmask = current->blocked; siginitset(¤t->blocked, mask); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - regs->rax = -EINTR; - while (1) { - current->state = TASK_INTERRUPTIBLE; - schedule(); - if (do_signal(regs, &saveset)) - return -EINTR; - } + current->state = TASK_INTERRUPTIBLE; + schedule(); + set_thread_flag(TIF_RESTORE_SIGMASK); + return -ERESTARTNOHAND; } asmlinkage long @@ -508,11 +502,11 @@ int ia32_setup_frame(int sig, struct k_s current->comm, current->pid, frame, regs->rip, frame->pretcode); #endif - return 1; + return 0; give_sigsegv: force_sigsegv(sig, current); - return 0; + return -EFAULT; } int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, @@ -595,7 +589,7 @@ int ia32_setup_rt_frame(int sig, struct regs->ss = __USER32_DS; set_fs(USER_DS); - regs->eflags &= ~TF_MASK; + regs->eflags &= ~TF_MASK; if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); @@ -604,9 +598,9 @@ int ia32_setup_rt_frame(int sig, struct current->comm, current->pid, frame, regs->rip, frame->pretcode); #endif - return 1; + return 0; give_sigsegv: force_sigsegv(sig, current); - return 0; + return -EFAULT; } Index: linux/arch/x86_64/kernel/signal.c =================================================================== --- linux.orig/arch/x86_64/kernel/signal.c +++ linux/arch/x86_64/kernel/signal.c @@ -38,37 +38,6 @@ int ia32_setup_frame(int sig, struct k_s sigset_t *set, struct pt_regs * regs); asmlinkage long -sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs) -{ - sigset_t saveset, newset; - - /* XXX: Don't preclude handling different sized sigset_t's. */ - if (sigsetsize != sizeof(sigset_t)) - return -EINVAL; - - if (copy_from_user(&newset, unewset, sizeof(newset))) - return -EFAULT; - sigdelsetmask(&newset, ~_BLOCKABLE); - - spin_lock_irq(¤t->sighand->siglock); - saveset = current->blocked; - current->blocked = newset; - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); -#ifdef DEBUG_SIG - printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n", - saveset, newset, regs, regs->rip); -#endif - regs->rax = -EINTR; - while (1) { - current->state = TASK_INTERRUPTIBLE; - schedule(); - if (do_signal(regs, &saveset)) - return -EINTR; - } -} - -asmlinkage long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, struct pt_regs *regs) { @@ -341,11 +310,11 @@ static int setup_rt_frame(int sig, struc current->comm, current->pid, frame, regs->rip, frame->pretcode); #endif - return 1; + return 0; give_sigsegv: force_sigsegv(sig, current); - return 0; + return -EFAULT; } /* @@ -408,7 +377,7 @@ handle_signal(unsigned long sig, siginfo #endif ret = setup_rt_frame(sig, ka, info, oldset, regs); - if (ret) { + if (ret == 0) { spin_lock_irq(¤t->sighand->siglock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) @@ -425,11 +394,12 @@ handle_signal(unsigned long sig, siginfo * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. */ -int do_signal(struct pt_regs *regs, sigset_t *oldset) +static void do_signal(struct pt_regs *regs) { struct k_sigaction ka; siginfo_t info; int signr; + sigset_t *oldset; /* * We want the common case to go fast, which @@ -438,9 +408,11 @@ int do_signal(struct pt_regs *regs, sigs * if so. */ if (!user_mode(regs)) - return 1; + return; - if (!oldset) + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + oldset = ¤t->saved_sigmask; + else oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); @@ -454,30 +426,46 @@ int do_signal(struct pt_regs *regs, sigs set_debugreg(current->thread.debugreg7, 7); /* Whee! Actually deliver the signal. */ - return handle_signal(signr, &info, &ka, oldset, regs); + if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { + /* a signal was successfully delivered; the saved + * sigmask will have been stored in the signal frame, + * and will be restored by sigreturn, so we can simply + * clear the TIF_RESTORE_SIGMASK flag */ + clear_thread_flag(TIF_RESTORE_SIGMASK); + } + return; } /* Did we come from a system call? */ if ((long)regs->orig_rax >= 0) { /* Restart the system call - no handlers present */ long res = regs->rax; - if (res == -ERESTARTNOHAND || - res == -ERESTARTSYS || - res == -ERESTARTNOINTR) { + switch (res) { + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: regs->rax = regs->orig_rax; regs->rip -= 2; - } - if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) { + break; + case -ERESTART_RESTARTBLOCK: regs->rax = test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall; regs->rip -= 2; + break; } } - return 0; + + /* if there's no signal to deliver, we just put the saved sigmask + back. */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) { + clear_thread_flag(TIF_RESTORE_SIGMASK); + sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); + } } -void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, __u32 thread_info_flags) +void +do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) { #ifdef DEBUG_SIG printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n", @@ -491,8 +479,8 @@ void do_notify_resume(struct pt_regs *re } /* deal with pending signal delivery */ - if (thread_info_flags & _TIF_SIGPENDING) - do_signal(regs,oldset); + if (thread_info_flags & (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK)) + do_signal(regs); } void signal_fault(struct pt_regs *regs, void __user *frame, char *where) Index: linux/include/asm-x86_64/signal.h =================================================================== --- linux.orig/include/asm-x86_64/signal.h +++ linux/include/asm-x86_64/signal.h @@ -24,10 +24,6 @@ typedef struct { } sigset_t; -struct pt_regs; -asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); - - #else /* Here we must cater to libcs that poke about in kernel headers. */ Index: linux/include/asm-x86_64/thread_info.h =================================================================== --- linux.orig/include/asm-x86_64/thread_info.h +++ linux/include/asm-x86_64/thread_info.h @@ -114,6 +114,7 @@ static inline struct thread_info *stack_ #define TIF_IRET 5 /* force IRET */ #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ #define TIF_SECCOMP 8 /* secure computing */ +#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal */ /* 16 free */ #define TIF_IA32 17 /* 32bit process */ #define TIF_FORK 18 /* ret_from_fork */ @@ -128,6 +129,7 @@ static inline struct thread_info *stack_ #define _TIF_IRET (1<