From: Ben Hutchings <ben@decadent.org.uk>
Date: Mon, 24 Aug 2020 23:43:33 +0000 (+0100)
Subject: [klibc] signal: Note another reason to define _KLIBC_NEEDS_SA_RESTORER
X-Git-Tag: archive/raspbian/2.0.8-6+rpi1^2~11
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=22109d0800ae46324128cd8400960a75fbd99a26;p=klibc.git

[klibc] signal: Note another reason to define _KLIBC_NEEDS_SA_RESTORER

Origin: https://git.kernel.org/pub/scm/libs/klibc/klibc.git/commit/?id=ccc5c14c44f3fa76f61b8aae947cf3b853a6c833

On some architectures we should set SA_RESTORER to avoid the need for
a signal trampoline and executable stack.

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

Gbp-Pq: Name 0001-klibc-signal-Note-another-reason-to-define-_KLIBC_NE.patch
---

diff --git a/usr/include/klibc/sysconfig.h b/usr/include/klibc/sysconfig.h
index c91d5b8..4e38b1f 100644
--- a/usr/include/klibc/sysconfig.h
+++ b/usr/include/klibc/sysconfig.h
@@ -154,7 +154,8 @@
  *
  *	Some architectures, like x86-64 and some i386 Fedora kernels,
  *	do not provide a default sigreturn, and therefore must have
- *	SA_RESTORER set.
+ *	SA_RESTORER set.  On others, the default sigreturn requires an
+ *	executable stack, which we should avoid.
  */
 #ifndef _KLIBC_NEEDS_SA_RESTORER
 # define _KLIBC_NEEDS_SA_RESTORER 0
diff --git a/usr/klibc/sigaction.c b/usr/klibc/sigaction.c
index 19a8a54..37201f7 100644
--- a/usr/klibc/sigaction.c
+++ b/usr/klibc/sigaction.c
@@ -30,8 +30,6 @@ int sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
 		sa = *act;
 		act = &sa;
 
-		/* The kernel can't be trusted to have a valid default
-		   restorer */
 		sa.sa_flags |= SA_RESTORER;
 		sa.sa_restorer = &__sigreturn;
 	}