From e289cb8fe70bb066898d1bd33ca6f58dfad82f2b Mon Sep 17 00:00:00 2001
From: Jake Burkholder <jake@FreeBSD.org>
Date: Mon, 29 Apr 2002 18:08:26 +0000
Subject: [PATCH] Add support for an alternate signal trampoline; add a sysarch
 call to register an alternate trampoling with the kernel.

---
 sys/sparc64/include/proc.h        |  1 +
 sys/sparc64/include/sysarch.h     |  6 ++++++
 sys/sparc64/sparc64/machdep.c     |  7 ++++++-
 sys/sparc64/sparc64/sys_machdep.c | 22 ++++++++++++++++++++++
 sys/sparc64/sparc64/vm_machdep.c  |  2 ++
 5 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/sys/sparc64/include/proc.h b/sys/sparc64/include/proc.h
index 108bc4282a02..a5307d88ec5d 100644
--- a/sys/sparc64/include/proc.h
+++ b/sys/sparc64/include/proc.h
@@ -52,6 +52,7 @@ struct mdthread {
 
 struct mdproc {
 	struct	md_utrap *md_utrap;
+	void	*md_sigtramp;
 };
 
 #endif /* !_MACHINE_PROC_H_ */
diff --git a/sys/sparc64/include/sysarch.h b/sys/sparc64/include/sysarch.h
index e9db27fb9e4c..104a9e5ae780 100644
--- a/sys/sparc64/include/sysarch.h
+++ b/sys/sparc64/include/sysarch.h
@@ -41,12 +41,18 @@
 #define _MACHINE_SYSARCH_H_
 
 #define	SPARC_UTRAP_INSTALL	1
+#define	SPARC_SIGTRAMP_INSTALL	2
 
 struct sparc_utrap_install_args {
 	int num;
 	const struct sparc_utrap_args *handlers;
 };
 
+struct sparc_sigtramp_install_args {
+	void	*sia_new;
+	void	**sia_old;
+};
+
 struct sparc_utrap_args {
 	utrap_entry_t type;
 	utrap_handler_t new_precise;
diff --git a/sys/sparc64/sparc64/machdep.c b/sys/sparc64/sparc64/machdep.c
index 143607080b88..d68d18c103a5 100644
--- a/sys/sparc64/sparc64/machdep.c
+++ b/sys/sparc64/sparc64/machdep.c
@@ -282,6 +282,7 @@ sparc64_init(caddr_t mdp, u_long o1, u_long o2, u_long o3, ofw_vec_t *vec)
 	 * Initialize proc0 stuff (p_contested needs to be done early).
 	 */
 	proc_linkup(&proc0, &proc0.p_ksegrp, &proc0.p_kse, &thread0);
+	proc0.p_md.md_sigtramp = NULL;
 	proc0.p_md.md_utrap = NULL;
 	proc0.p_uarea = (struct user *)uarea0;
 	proc0.p_stats = &proc0.p_uarea->u_stats;
@@ -418,7 +419,10 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 		/* NOTREACHED */
 	}
 
-	tf->tf_tpc = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	if (p->p_md.md_sigtramp != NULL)
+		tf->tf_tpc = (u_long)p->p_md.md_sigtramp;
+	else
+		tf->tf_tpc = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
 	tf->tf_tnpc = tf->tf_tpc + 4;
 	tf->tf_sp = (u_long)fp - SPOFF;
 
@@ -580,6 +584,7 @@ setregs(struct thread *td, u_long entry, u_long stack, u_long ps_strings)
 	u_long sp;
 
 	/* XXX no cpu_exec */
+	td->td_proc->p_md.md_sigtramp = NULL;
 	if ((ut = td->td_proc->p_md.md_utrap) != NULL) {
 		ut->ut_refcnt--;
 		if (ut->ut_refcnt == 0)
diff --git a/sys/sparc64/sparc64/sys_machdep.c b/sys/sparc64/sparc64/sys_machdep.c
index 9025f596b81d..34be95acf580 100644
--- a/sys/sparc64/sparc64/sys_machdep.c
+++ b/sys/sparc64/sparc64/sys_machdep.c
@@ -35,6 +35,7 @@
 #include <machine/utrap.h>
 #include <machine/sysarch.h>
 
+static int sparc_sigtramp_install(struct thread *td, char *args);
 static int sparc_utrap_install(struct thread *td, char *args);
 
 #ifndef	_SYS_SYSPROTO_H_
@@ -51,6 +52,9 @@ sysarch(struct thread *td, struct sysarch_args *uap)
 
 	error = 0;
 	switch (uap->op) {
+	case SPARC_SIGTRAMP_INSTALL:
+		error = sparc_sigtramp_install(td, uap->parms);
+		break;
 	case SPARC_UTRAP_INSTALL:
 		error = sparc_utrap_install(td, uap->parms);
 		break;
@@ -61,6 +65,24 @@ sysarch(struct thread *td, struct sysarch_args *uap)
 	return (error);
 }
 
+static int
+sparc_sigtramp_install(struct thread *td, char *args)
+{
+	struct sparc_sigtramp_install_args sia;
+	struct proc *p;
+	int error;
+
+	p = td->td_proc;
+	if ((error = copyin(args, &sia, sizeof(sia))) != 0)
+		return (error);
+	if (sia.sia_old != NULL) {
+		if (suword(sia.sia_old, (long)p->p_md.md_sigtramp) != 0)
+			return (EFAULT);
+	}
+	p->p_md.md_sigtramp = sia.sia_new;
+	return (0);
+}
+
 static int
 sparc_utrap_install(struct thread *td, char *args)
 {
diff --git a/sys/sparc64/sparc64/vm_machdep.c b/sys/sparc64/sparc64/vm_machdep.c
index eb49c5866015..fe8eb00a8c63 100644
--- a/sys/sparc64/sparc64/vm_machdep.c
+++ b/sys/sparc64/sparc64/vm_machdep.c
@@ -77,6 +77,7 @@ cpu_exit(struct thread *td)
 	struct proc *p;
 
 	p = td->td_proc;
+	p->p_md.md_sigtramp = NULL;
 	if ((ut = p->p_md.md_utrap) != NULL) {
 		ut->ut_refcnt--;
 		if (ut->ut_refcnt == 0)
@@ -108,6 +109,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 	if ((flags & RFPROC) == 0)
 		return;
 
+	p2->p_md.md_sigtramp = td1->td_proc->p_md.md_sigtramp;
 	if ((ut = td1->td_proc->p_md.md_utrap) != NULL)
 		ut->ut_refcnt++;
 	p2->p_md.md_utrap = ut;