MFC r198507:

Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals.

MFC r198590:
Trapsignal() calls kern_sigprocmask() when delivering catched signal
with proc lock held.

MFC r198670:
For trapsignal() and postsig(), kern_sigprocmask() is called with
both process lock and curproc->p_sigacts->ps_mtx locked. Prevent lock
recursion on ps_mtx in reschedule_signals().

2 files changed, 12 insertions, 33 deletions

diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 67a64c9..801af7c 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -756,7 +756,6 @@ osigreturn(td, uap)
 	struct osigcontext sc;
 	struct trapframe *regs;
 	struct osigcontext *scp;
-	struct proc *p = td->td_proc;
 	int eflags, error;
 	ksiginfo_t ksi;
 
@@ -856,17 +855,14 @@ osigreturn(td, uap)
 	regs->tf_eip = scp->sc_pc;
 	regs->tf_eflags = eflags;
 
-	PROC_LOCK(p);
 #if defined(COMPAT_43)
 	if (scp->sc_onstack & 1)
 		td->td_sigstk.ss_flags |= SS_ONSTACK;
 	else
 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
 #endif
-	SIGSETOLD(td->td_sigmask, scp->sc_mask);
-	SIG_CANTMASK(td->td_sigmask);
-	signotify(td);
-	PROC_UNLOCK(p);
+	kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
+	    SIGPROCMASK_OLD);
 	return (EJUSTRETURN);
 }
 #endif /* COMPAT_43 */
@@ -883,9 +879,8 @@ freebsd4_sigreturn(td, uap)
 	} */ *uap;
 {
 	struct ucontext4 uc;
-	struct proc *p = td->td_proc;
 	struct trapframe *regs;
-	const struct ucontext4 *ucp;
+	struct ucontext4 *ucp;
 	int cs, eflags, error;
 	ksiginfo_t ksi;
 
@@ -973,18 +968,13 @@ freebsd4_sigreturn(td, uap)
 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs));
 	}
 
-	PROC_LOCK(p);
 #if defined(COMPAT_43)
 	if (ucp->uc_mcontext.mc_onstack & 1)
 		td->td_sigstk.ss_flags |= SS_ONSTACK;
 	else
 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
 #endif
-
-	td->td_sigmask = ucp->uc_sigmask;
-	SIG_CANTMASK(td->td_sigmask);
-	signotify(td);
-	PROC_UNLOCK(p);
+	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
 	return (EJUSTRETURN);
 }
 #endif	/* COMPAT_FREEBSD4 */
@@ -1000,9 +990,8 @@ sigreturn(td, uap)
 	} */ *uap;
 {
 	ucontext_t uc;
-	struct proc *p = td->td_proc;
 	struct trapframe *regs;
-	const ucontext_t *ucp;
+	ucontext_t *ucp;
 	int cs, eflags, error, ret;
 	ksiginfo_t ksi;
 
@@ -1094,7 +1083,6 @@ sigreturn(td, uap)
 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs));
 	}
 
-	PROC_LOCK(p);
 #if defined(COMPAT_43)
 	if (ucp->uc_mcontext.mc_onstack & 1)
 		td->td_sigstk.ss_flags |= SS_ONSTACK;
@@ -1102,10 +1090,7 @@ sigreturn(td, uap)
 		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
 #endif
 
-	td->td_sigmask = ucp->uc_sigmask;
-	SIG_CANTMASK(td->td_sigmask);
-	signotify(td);
-	PROC_UNLOCK(p);
+	kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
 	return (EJUSTRETURN);
 }
 
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index d07f655..069b5bb 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -667,10 +667,10 @@ linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 int
 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
 {
-	struct proc *p = td->td_proc;
 	struct l_sigframe frame;
 	struct trapframe *regs;
 	l_sigset_t lmask;
+	sigset_t bmask;
 	int eflags, i;
 	ksiginfo_t ksi;
 
@@ -725,11 +725,8 @@ linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
 	lmask.__bits[0] = frame.sf_sc.sc_mask;
 	for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
 		lmask.__bits[i+1] = frame.sf_extramask[i];
-	PROC_LOCK(p);
-	linux_to_bsd_sigset(&lmask, &td->td_sigmask);
-	SIG_CANTMASK(td->td_sigmask);
-	signotify(td);
-	PROC_UNLOCK(p);
+	linux_to_bsd_sigset(&lmask, &bmask);
+	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
 
 	/*
 	 * Restore signal context.
@@ -767,9 +764,9 @@ linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
 int
 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
 {
-	struct proc *p = td->td_proc;
 	struct l_ucontext uc;
 	struct l_sigcontext *context;
+	sigset_t bmask;
 	l_stack_t *lss;
 	stack_t ss;
 	struct trapframe *regs;
@@ -826,11 +823,8 @@ linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
 		return(EINVAL);
 	}
 
-	PROC_LOCK(p);
-	linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask);
-	SIG_CANTMASK(td->td_sigmask);
-	signotify(td);
-	PROC_UNLOCK(p);
+	linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
+	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
 
 	/*
 	 * Restore signal context