Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1d001df1 authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
Browse files

[PATCH] 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: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 3adbbcce

arch/x86_64/ia32/ia32_signal.c

+11 −17
Original line number Diff line number Diff line
@@ -113,25 +113,19 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) 
}



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(&current->sighand->siglock);

	saveset = current->blocked;

	current->saved_sigmask = current->blocked;

	siginitset(&current->blocked, mask);

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	regs->rax = -EINTR;

	while (1) {

	current->state = TASK_INTERRUPTIBLE;

	schedule();

		if (do_signal(regs, &saveset))

			return -EINTR;

	}

	set_thread_flag(TIF_RESTORE_SIGMASK);

	return -ERESTARTNOHAND;

}



asmlinkage long
@@ -508,11 +502,11 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, 
		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,
@@ -604,9 +598,9 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
		current->comm, current->pid, frame, regs->rip, frame->pretcode);

#endif



	return 1;

	return 0;



give_sigsegv:

	force_sigsegv(sig, current);

	return 0;

	return -EFAULT;

}

arch/x86_64/kernel/signal.c

+35 −47
Original line number Diff line number Diff line
@@ -37,37 +37,6 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
int ia32_setup_frame(int sig, struct k_sigaction *ka,

            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(&current->sighand->siglock);

	saveset = current->blocked;

	current->blocked = newset;

	recalc_sigpending();

	spin_unlock_irq(&current->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, struct k_sigaction *ka, siginfo_t *info, 
		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_t *info, struct k_sigaction *ka, 
#endif

	ret = setup_rt_frame(sig, ka, info, oldset, regs);



	if (ret) {

	if (ret == 0) {

		spin_lock_irq(&current->sighand->siglock);

		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);

		if (!(ka->sa.sa_flags & SA_NODEFER))
@@ -425,11 +394,12 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 
 * 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, sigset_t *oldset) 
	 * if so.

	 */

	if (!user_mode(regs))

		return 1;

		return;



	if (!oldset)

	if (test_thread_flag(TIF_RESTORE_SIGMASK))

		oldset = &current->saved_sigmask;

	else

		oldset = &current->blocked;



	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
@@ -454,30 +426,46 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset) 
			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, &current->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 *regs, sigset_t *oldset, __u32 thread_info_ 
	}



	/* 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)

include/asm-x86_64/signal.h

+0 −4
Original line number Diff line number Diff line
@@ -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.  */

include/asm-x86_64/thread_info.h

+2 −0
Original line number Diff line number Diff line
@@ -114,6 +114,7 @@ static inline struct thread_info *stack_thread_info(void) 
#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_thread_info(void) 
#define _TIF_IRET		(1<<TIF_IRET)

#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)

#define _TIF_SECCOMP		(1<<TIF_SECCOMP)

#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)

#define _TIF_IA32		(1<<TIF_IA32)

#define _TIF_FORK		(1<<TIF_FORK)

#define _TIF_ABI_PENDING	(1<<TIF_ABI_PENDING)

include/asm-x86_64/unistd.h

+1 −0
Original line number Diff line number Diff line
@@ -658,6 +658,7 @@ do { \ 
#define __ARCH_WANT_SYS_SIGPENDING

#define __ARCH_WANT_SYS_SIGPROCMASK

#define __ARCH_WANT_SYS_RT_SIGACTION

#define __ARCH_WANT_SYS_RT_SIGSUSPEND

#define __ARCH_WANT_SYS_TIME

#define __ARCH_WANT_COMPAT_SYS_TIME