According to Linux man sigaltstack(3) shall return EINVAL if the ss

argument is not a null pointer, and the ss_flags member pointed to by ss
contains flags other than SS_DISABLE. However, in fact, Linux also
allows SS_ONSTACK flag which is simply ignored.

For buggy apps (at least mono) ignore other than SS_DISABLE
flags as a Linux do.

While here move MI part of sigaltstack code to the appropriate place.

Reported by:	abi at abinet dot ru

8 files changed, 28 insertions, 79 deletions

diff --git a/sys/amd64/linux/linux.h b/sys/amd64/linux/linux.h
index 0845809..b4e7190 100644
--- a/sys/amd64/linux/linux.h
+++ b/sys/amd64/linux/linux.h
@@ -250,9 +250,6 @@ struct l_newstat {
 #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	(*l_handler_t)(l_int);
 
 typedef struct {
diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c
index d8704fd..8b0da51 100644
--- a/sys/amd64/linux/linux_machdep.c
+++ b/sys/amd64/linux/linux_machdep.c
@@ -87,29 +87,6 @@ __FBSDID("$FreeBSD$");
 #include <compat/linux/linux_util.h>
 #include <compat/linux/linux_emul.h>
 
-int
-linux_to_bsd_sigaltstack(int lsa)
-{
-	int bsa = 0;
-
-	if (lsa & LINUX_SS_DISABLE)
-		bsa |= SS_DISABLE;
-	if (lsa & LINUX_SS_ONSTACK)
-		bsa |= SS_ONSTACK;
-	return (bsa);
-}
-
-int
-bsd_to_linux_sigaltstack(int bsa)
-{
-	int lsa = 0;
-
-	if (bsa & SS_DISABLE)
-		lsa |= LINUX_SS_DISABLE;
-	if (bsa & SS_ONSTACK)
-		lsa |= LINUX_SS_ONSTACK;
-	return (lsa);
-}
 
 int
 linux_execve(struct thread *td, struct linux_execve_args *args)
diff --git a/sys/amd64/linux32/linux.h b/sys/amd64/linux32/linux.h
index 001c86b..d76b44c 100644
--- a/sys/amd64/linux32/linux.h
+++ b/sys/amd64/linux32/linux.h
@@ -328,9 +328,6 @@ struct l_statfs64 {
 #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 l_uintptr_t l_handler_t;
 typedef l_ulong	l_osigset_t;
 
diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
index 4ecbef2..d84e58e 100644
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -84,34 +84,10 @@ struct l_old_select_argv {
 	l_uintptr_t	timeout;
 } __packed;
 
-int
-linux_to_bsd_sigaltstack(int lsa)
-{
-	int bsa = 0;
-
-	if (lsa & LINUX_SS_DISABLE)
-		bsa |= SS_DISABLE;
-	if (lsa & LINUX_SS_ONSTACK)
-		bsa |= SS_ONSTACK;
-	return (bsa);
-}
-
 static int	linux_mmap_common(struct thread *td, l_uintptr_t addr,
 		    l_size_t len, l_int prot, l_int flags, l_int fd,
 		    l_loff_t pos);
 
-int
-bsd_to_linux_sigaltstack(int bsa)
-{
-	int lsa = 0;
-
-	if (bsa & SS_DISABLE)
-		lsa |= LINUX_SS_DISABLE;
-	if (bsa & SS_ONSTACK)
-		lsa |= LINUX_SS_ONSTACK;
-	return (lsa);
-}
-
 static void
 bsd_to_linux_rusage(struct rusage *ru, struct l_rusage *lru)
 {
diff --git a/sys/compat/linux/linux_signal.c b/sys/compat/linux/linux_signal.c
index 856d433..f60e731 100644
--- a/sys/compat/linux/linux_signal.c
+++ b/sys/compat/linux/linux_signal.c
@@ -754,6 +754,32 @@ siginfo_to_lsiginfo(const siginfo_t *si, l_siginfo_t *lsi, l_int sig)
 	}
 }
 
+int
+linux_to_bsd_sigaltstack(int lsa)
+{
+	int bsa = 0;
+
+	if (lsa & LINUX_SS_DISABLE)
+		bsa |= SS_DISABLE;
+	/*
+	 * Linux ignores SS_ONSTACK flag for ss
+	 * parameter while FreeBSD prohibits it.
+	 */
+	return (bsa);
+}
+
+int
+bsd_to_linux_sigaltstack(int bsa)
+{
+	int lsa = 0;
+
+	if (bsa & SS_DISABLE)
+		lsa |= LINUX_SS_DISABLE;
+	if (bsa & SS_ONSTACK)
+		lsa |= LINUX_SS_ONSTACK;
+	return (lsa);
+}
+
 void
 lsiginfo_to_ksiginfo(const l_siginfo_t *lsi, ksiginfo_t *ksi, int sig)
 {
diff --git a/sys/compat/linux/linux_signal.h b/sys/compat/linux/linux_signal.h
index 21b557a..eb06bb0 100644
--- a/sys/compat/linux/linux_signal.h
+++ b/sys/compat/linux/linux_signal.h
@@ -46,6 +46,8 @@
 extern int bsd_to_linux_signal[];
 extern int linux_to_bsd_signal[];
 
+int linux_to_bsd_sigaltstack(int lsa);
+int bsd_to_linux_sigaltstack(int bsa);
 void linux_to_bsd_sigset(l_sigset_t *, sigset_t *);
 void bsd_to_linux_sigset(sigset_t *, l_sigset_t *);
 int linux_do_sigaction(struct thread *, int, l_sigaction_t *, l_sigaction_t *);
diff --git a/sys/i386/linux/linux.h b/sys/i386/linux/linux.h
index 3087dac..ae12499 100644
--- a/sys/i386/linux/linux.h
+++ b/sys/i386/linux/linux.h
@@ -303,9 +303,6 @@ struct l_statfs64 {
 #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	(*l_handler_t)(l_int);
 typedef l_ulong	l_osigset_t;
 
diff --git a/sys/i386/linux/linux_machdep.c b/sys/i386/linux/linux_machdep.c
index cd8bf0d..7c663e5 100644
--- a/sys/i386/linux/linux_machdep.c
+++ b/sys/i386/linux/linux_machdep.c
@@ -99,29 +99,6 @@ static int	linux_mmap_common(struct thread *td, l_uintptr_t addr,
 		    l_size_t len, l_int prot, l_int flags, l_int fd,
 		    l_loff_t pos);
 
-int
-linux_to_bsd_sigaltstack(int lsa)
-{
-	int bsa = 0;
-
-	if (lsa & LINUX_SS_DISABLE)
-		bsa |= SS_DISABLE;
-	if (lsa & LINUX_SS_ONSTACK)
-		bsa |= SS_ONSTACK;
-	return (bsa);
-}
-
-int
-bsd_to_linux_sigaltstack(int bsa)
-{
-	int lsa = 0;
-
-	if (bsa & SS_DISABLE)
-		lsa |= LINUX_SS_DISABLE;
-	if (bsa & SS_ONSTACK)
-		lsa |= LINUX_SS_ONSTACK;
-	return (lsa);
-}
 
 int
 linux_execve(struct thread *td, struct linux_execve_args *args)