Make sigaltstack as per-threaded, because per-process sigaltstack state

is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.

Reviewed by: deischen, dfr

2 files changed, 31 insertions, 31 deletions

diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 755eef4..524e226 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -271,12 +271,12 @@ osendsig(catcher, sig, mask, code)
 	oonstack = sigonstack(regs->tf_esp);
 
 	/* Allocate space for the signal handler context. */
-	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
+	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct osigframe *)(p->p_sigstk.ss_sp +
-		    p->p_sigstk.ss_size - sizeof(struct osigframe));
+		fp = (struct osigframe *)(td->td_sigstk.ss_sp +
+		    td->td_sigstk.ss_size - sizeof(struct osigframe));
 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
-		p->p_sigstk.ss_flags |= SS_ONSTACK;
+		td->td_sigstk.ss_flags |= SS_ONSTACK;
 #endif
 	} else
 		fp = (struct osigframe *)regs->tf_esp - 1;
@@ -403,20 +403,20 @@ freebsd4_sendsig(catcher, sig, mask, code)
 	/* Save user context. */
 	bzero(&sf, sizeof(sf));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = p->p_sigstk;
-	sf.sf_uc.uc_stack.ss_flags = (p->p_flag & P_ALTSTACK)
+	sf.sf_uc.uc_stack = td->td_sigstk;
+	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(*regs));
 
 	/* Allocate space for the signal handler context. */
-	if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
+	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sfp = (struct sigframe4 *)(p->p_sigstk.ss_sp +
-		    p->p_sigstk.ss_size - sizeof(struct sigframe4));
+		sfp = (struct sigframe4 *)(td->td_sigstk.ss_sp +
+		    td->td_sigstk.ss_size - sizeof(struct sigframe4));
 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
-		p->p_sigstk.ss_flags |= SS_ONSTACK;
+		td->td_sigstk.ss_flags |= SS_ONSTACK;
 #endif
 	} else
 		sfp = (struct sigframe4 *)regs->tf_esp - 1;
@@ -537,8 +537,8 @@ sendsig(catcher, sig, mask, code)
 	/* Save user context. */
 	bzero(&sf, sizeof(sf));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = p->p_sigstk;
-	sf.sf_uc.uc_stack.ss_flags = (p->p_flag & P_ALTSTACK)
+	sf.sf_uc.uc_stack = td->td_sigstk;
+	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
 	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
 	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
@@ -548,12 +548,12 @@ sendsig(catcher, sig, mask, code)
 	fpstate_drop(td);
 
 	/* Allocate space for the signal handler context. */
-	if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
+	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sp = p->p_sigstk.ss_sp +
-		    p->p_sigstk.ss_size - sizeof(struct sigframe);
+		sp = td->td_sigstk.ss_sp +
+		    td->td_sigstk.ss_size - sizeof(struct sigframe);
 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
-		p->p_sigstk.ss_flags |= SS_ONSTACK;
+		td->td_sigstk.ss_flags |= SS_ONSTACK;
 #endif
 	} else
 		sp = (char *)regs->tf_esp - sizeof(struct sigframe);
@@ -771,9 +771,9 @@ osigreturn(td, uap)
 	PROC_LOCK(p);
 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
 	if (scp->sc_onstack & 1)
-		p->p_sigstk.ss_flags |= SS_ONSTACK;
+		td->td_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
+		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
 #endif
 	SIGSETOLD(td->td_sigmask, scp->sc_mask);
 	SIG_CANTMASK(td->td_sigmask);
@@ -878,9 +878,9 @@ freebsd4_sigreturn(td, uap)
 	PROC_LOCK(p);
 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
 	if (ucp->uc_mcontext.mc_onstack & 1)
-		p->p_sigstk.ss_flags |= SS_ONSTACK;
+		td->td_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
+		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
 #endif
 
 	td->td_sigmask = ucp->uc_sigmask;
@@ -988,9 +988,9 @@ sigreturn(td, uap)
 	PROC_LOCK(p);
 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
 	if (ucp->uc_mcontext.mc_onstack & 1)
-		p->p_sigstk.ss_flags |= SS_ONSTACK;
+		td->td_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
+		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
 #endif
 
 	td->td_sigmask = ucp->uc_sigmask;
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index dbaea80..5321d21 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -290,10 +290,10 @@ linux_rt_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	/*
 	 * Allocate space for the signal handler context.
 	 */
-	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
+	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct l_rt_sigframe *)(p->p_sigstk.ss_sp +
-		    p->p_sigstk.ss_size - sizeof(struct l_rt_sigframe));
+		fp = (struct l_rt_sigframe *)(td->td_sigstk.ss_sp +
+		    td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
 	} else
 		fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
 	mtx_unlock(&psp->ps_mtx);
@@ -323,9 +323,9 @@ linux_rt_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	frame.sf_sc.uc_flags = 0;		/* XXX ??? */
 	frame.sf_sc.uc_link = NULL;		/* XXX ??? */
 
-	frame.sf_sc.uc_stack.ss_sp = p->p_sigstk.ss_sp;
-	frame.sf_sc.uc_stack.ss_size = p->p_sigstk.ss_size;
-	frame.sf_sc.uc_stack.ss_flags = (p->p_flag & P_ALTSTACK)
+	frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
+	frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
+	frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
 	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
 	PROC_UNLOCK(p);
 
@@ -431,10 +431,10 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	/*
 	 * Allocate space for the signal handler context.
 	 */
-	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
+	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct l_sigframe *)(p->p_sigstk.ss_sp +
-		    p->p_sigstk.ss_size - sizeof(struct l_sigframe));
+		fp = (struct l_sigframe *)(td->td_sigstk.ss_sp +
+		    td->td_sigstk.ss_size - sizeof(struct l_sigframe));
 	} else
 		fp = (struct l_sigframe *)regs->tf_esp - 1;
 	mtx_unlock(&psp->ps_mtx);