[klibc] signal: Add sysconfig setting to force SA_SIGINFO on

Origin: https://git.kernel.org/pub/scm/libs/klibc/klibc.git/commit/?id=2a2a0b6b79c2470f529daabd5c193f58fe188337

On alpha, arm, i386, m68k, powerpc, s390, sh, and sparc (32-bit), the
kernel sets up the signal stack frame differently depending on the
SA_SIGINFO flag, not whether the sigaction() or rt_sigaction() system
call was used to install the handler.

On alpha and sparc, we are going to start providing our own restorer
that will call rt_sigaction(), so will need to ensure this flag is
always set.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Gbp-Pq: Name 0002-klibc-signal-Add-sysconfig-setting-to-force-SA_SIGIN.patch

diff --git a/usr/include/klibc/sysconfig.h b/usr/include/klibc/sysconfig.h
index 4e38b1fd1e1dddf522892311a6d42dcef18295a0..5722e04f8c57b3a27e01b018e250c09d50bab18c 100644 (file)
--- a/usr/include/klibc/sysconfig.h
+++ b/usr/include/klibc/sysconfig.h
@@ -162,6 +162,20 @@
 #endif
 
 
+/*
+ * _KLIBC_NEEDS_SA_SIGINFO:
+ *
+ *     On some architectures, the signal stack frame is set up for
+ *     either sigreturn() or rt_sigreturn() depending on whether
+ *     SA_SIGINFO is set.  Where this is the case, and we provide our
+ *     own restorer function, this must also be set so that the
+ *     restorer can always use rt_sigreturn().
+ */
+#ifndef _KLIBC_NEEDS_SA_SIGINFO
+# define _KLIBC_NEEDS_SA_SIGINFO 0
+#endif
+
+
 /*
  * _KLIBC_STATFS_F_TYPE_64:
  *

diff --git a/usr/klibc/sigaction.c b/usr/klibc/sigaction.c
index 37201f7df3747b90b36cb3ce8232e889d47972af..dbf8e2202e2f6ed845cd4c27d03e35d313129df2 100644 (file)
--- a/usr/klibc/sigaction.c
+++ b/usr/klibc/sigaction.c
@@ -21,19 +21,26 @@ __extern int __rt_sigaction(int, const struct sigaction *, struct sigaction *,
 
 int sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
 {
-       int rv;
-
+       unsigned int needed_flags = 0
 #if _KLIBC_NEEDS_SA_RESTORER
+               | SA_RESTORER
+#endif
+#if _KLIBC_NEEDS_SA_SIGINFO
+               | SA_SIGINFO
+#endif
+               ;
        struct sigaction sa;
+       int rv;
 
-       if (act && !(act->sa_flags & SA_RESTORER)) {
+       if (act && (act->sa_flags & needed_flags) != needed_flags) {
                sa = *act;
+               sa.sa_flags |= needed_flags;
+#if _KLIBC_NEEDS_SA_RESTORER
+               if (!(act->sa_flags & SA_RESTORER))
+                       sa.sa_restorer = &__sigreturn;
+#endif
                act = &sa;
-
-               sa.sa_flags |= SA_RESTORER;
-               sa.sa_restorer = &__sigreturn;
        }
-#endif
 
 #if _KLIBC_USE_RT_SIG
 # ifdef __sparc__