This is the first of 3 commits that will get IBM's JDK 1.3 working

with FreeBSD (not including the MINSIGSTKSZ issue, which belongs to
Marcel).  Due to time constraints, I'm going to space them out over a
few days.

This fixes two problems with linux_sigaltstack()

o ss == 0 is perfectly valid use, so do not fail in this case.

o Fix flag handling:
 - Our SS_DISABLE is 4, linux's is 2, so we need conversion routines.
	These conversion routines will be needed by linux_rt_sendsig()
	and linux_rt_sigreturn (forthcoming), so they are not static.
 - Linux's flag 0 historically meant SS_ONSTACK according to a comment
	in their linux/kernel/signal.c file.

Among other things, this fixes a warning from Sun's JDK 1.3:
"Java HotSpot(TM) Client VM warning: cannot uninstall alt signal stack"

Reviewed by: marcel
Tested by:   sto@stat.duke.edu, many others on freebsd-java@

1 files changed, 8 insertions, 0 deletions

diff --git a/sys/i386/linux/linux.h b/sys/i386/linux/linux.h
index 8887ec36f67e..f399f054441f 100644
--- a/sys/i386/linux/linux.h
+++ b/sys/i386/linux/linux.h
@@ -159,6 +159,14 @@ struct linux_new_utsname {
 
 /* sigaltstack */
 #define LINUX_MINSIGSTKSZ	2048
+#define LINUX_SS_ONSTACK_BC	0 	/* backwards compat SS_ONSTACK */
+#define LINUX_SS_ONSTACK	1
+#define LINUX_SS_DISABLE	2
+
+
+int linux_to_bsd_sigaltstack(int lsa);
+int bsd_to_linux_sigaltstack(int bsa);
+
 
 typedef void	(*linux_handler_t)(int);
 typedef u_long	linux_osigset_t;