Fix implementation of signal() for x86-64, adjust for new kernel-headers

1 files changed, 21 insertions, 45 deletions

diff --git a/mdk-stage1/minilibc.c b/mdk-stage1/minilibc.c
index 0a9bc9156..7a7e6c561 100644
--- a/mdk-stage1/minilibc.c
+++ b/mdk-stage1/minilibc.c
@@ -61,60 +61,37 @@ void _fini (int __status __attribute__ ((unused)))
 }
 
 #ifdef __x86_64__
+/* x86-64 implementation of signal() derived from glibc sources */
 
-#define _NSIG           64
-#define _NSIG_BPW       64
-#define _NSIG_WORDS     (_NSIG / _NSIG_BPW)
-
-typedef struct {
-  unsigned long sig[_NSIG_WORDS];
-} libc_sigset_t;
-
-struct sigaction {
-  union {
-    __sighandler_t _sa_handler;
-    void (*_sa_sigaction)(int, void*, void*);
-  } _u;
-  unsigned long sa_flags;
-  void (*sa_restorer)(void);
-  libc_sigset_t sa_mask;
-};
-
-#define sa_handler      _u._sa_handler
-#define sa_sigaction    _u._sa_sigaction
-
-static inline int sigemptyset(libc_sigset_t *set) {
-  set->sig[0]=0;
-  if (_NSIG_WORDS>1) set->sig[1]=0;
-  if (_NSIG_WORDS>2) {
-    set->sig[2]=0;
-    set->sig[3]=0;
-  }
+static inline int sigemptyset(sigset_t *set) {
+  *set = 0;
   return 0;
 }
 
-#define __sigmask(sig)          ( ((unsigned long)1) << (((sig)-1) % (8*sizeof(unsigned long))) )
-#define __sigword(sig)          ( ((sig)-1) / (8*sizeof(unsigned long)) )
-
-#define EINVAL 22
-
-int sigaddset(libc_sigset_t *set, int signo) {
-  if ((signo<1)||(signo>SIGRTMAX)) {
-	errno = EINVAL;
-    return -1;
-  } else {
-    unsigned long __mask = __sigmask (signo);
-    unsigned long __word = __sigword (signo);
-    set->sig[__word]|=__mask;
-    return 0;
-  }
+static inline int sigaddset(sigset_t *set, int sig) {
+  __asm__("btsq %1,%0" : "=m" (*set) : "Ir" (sig - 1L) : "cc");
+  return 0;
 }
 
 #define __NR___rt_sigaction __NR_rt_sigaction
 static inline _syscall3(int,__rt_sigaction,int,signum,const void *,act,void *,oldact)
+#define __NR___rt_sigreturn __NR_rt_sigreturn
+static _syscall1(int,__rt_sigreturn,unsigned long,unused)
+
+static void restore_rt(void) {
+  __rt_sigreturn(0);
+}
 
 int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact) {
-  return __rt_sigaction(signum, act, oldact);
+  struct sigaction *newact = (struct sigaction *)act;
+  if (act) {
+	newact = __builtin_alloca(sizeof(*newact));
+	newact->sa_handler = act->sa_handler;
+	newact->sa_flags = act->sa_flags | SA_RESTORER;
+	newact->sa_restorer = &restore_rt;
+	newact->sa_mask = act->sa_mask;
+  }
+  return __rt_sigaction(signum, newact, oldact);
 }
 
 __sighandler_t signal(int signum, __sighandler_t action) {
@@ -329,4 +306,3 @@ void printf(char * fmt, ...)
 		}
 	}
 }
-