klibc - Aug 2020 - [klibc:master] signal: Add config flag for additional sigaction fixup

Commit-ID:  755b07d826618779a2232199cb53e2a44809ad89
Gitweb:    
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=755b07d826618779a2232199cb53e2a44809ad89
Author:     Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Fri, 28 Aug 2020 19:37:19 +0100
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Sat, 29 Aug 2020 17:22:38 +0100

[klibc] signal: Add config flag for additional sigaction fixup

On ia64, sigaction() needs to make further changes to the given
struct sigaction.  Add a config flag for this, that forces copying
of struct sigaction.

Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 usr/include/klibc/sysconfig.h | 11 +++++++++++
 usr/klibc/sigaction.c         | 20 ++++++++++++++------
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/usr/include/klibc/sysconfig.h b/usr/include/klibc/sysconfig.h
index 5722e04f..d658ad30 100644
--- a/usr/include/klibc/sysconfig.h
+++ b/usr/include/klibc/sysconfig.h
@@ -176,6 +176,17 @@
 #endif
 
 
+/*
+ * _KLIBC_NEEDS_SIGACTION_FIXUP
+ *
+ *	On some architectures, struct sigaction needs additional
+ *	changes before passing to the kernel.
+ */
+#ifndef _KLIBC_NEEDS_SIGACTION_FIXUP
+# define _KLIBC_NEEDS_SIGACTION_FIXUP 0
+#endif
+
+
 /*
  * _KLIBC_STATFS_F_TYPE_64:
  *
diff --git a/usr/klibc/sigaction.c b/usr/klibc/sigaction.c
index d2223843..a8181a41 100644
--- a/usr/klibc/sigaction.c
+++ b/usr/klibc/sigaction.c
@@ -8,11 +8,17 @@
 #include <klibc/sysconfig.h>
 
 __extern void __sigreturn(void);
+
+#if _KLIBC_NEEDS_SIGACTION_FIXUP
+typedef struct sigaction *act_type;
+#else
+typedef const struct sigaction *act_type;
+#endif
+
 #if _KLIBC_USE_RT_SIG
-__extern int __rt_sigaction(int, const struct sigaction *, struct sigaction *,
-			    size_t);
+__extern int __rt_sigaction(int, act_type, struct sigaction *, size_t);
 #else
-__extern int __sigaction(int, const struct sigaction *, struct sigaction *);
+__extern int __sigaction(int, act_type, struct sigaction *);
 #endif
 
 int sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
@@ -28,7 +34,9 @@ int sigaction(int sig, const struct sigaction *act, struct
sigaction *oact)
 	struct sigaction sa;
 	int rv;
 
-	if (act && (act->sa_flags & needed_flags) != needed_flags) {
+	if (act &&
+	    ((act->sa_flags & needed_flags) != needed_flags ||
+	     _KLIBC_NEEDS_SIGACTION_FIXUP)) {
 		sa = *act;
 		sa.sa_flags |= needed_flags;
 #if _KLIBC_NEEDS_SA_RESTORER
@@ -46,9 +54,9 @@ int sigaction(int sig, const struct sigaction *act, struct
sigaction *oact)
 			  + sizeof(sigset_t) == sizeof(struct sigaction)
 			  ? 1 : -1]);
 
-	rv = __rt_sigaction(sig, act, oact, sizeof(sigset_t));
+	rv = __rt_sigaction(sig, (act_type)act, oact, sizeof(sigset_t));
 #else
-	rv = __sigaction(sig, act, oact);
+	rv = __sigaction(sig, (act_type)act, oact);
 #endif
 
 #if _KLIBC_NEEDS_SA_RESTORER