[klibc] [klibc:execstack-fixes] sparc: Set sa_restorer for signals and disable executable stack
klibc-bot for Ben Hutchings
ben at decadent.org.uk
Sat Jul 25 14:24:04 PDT 2020
Commit-ID: 9370be8552652231e84f8b8424dec81cd8b1b1ab
Gitweb: http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=9370be8552652231e84f8b8424dec81cd8b1b1ab
Author: Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Thu, 30 Apr 2020 13:56:47 +0100
Committer: Ben Hutchings <ben at decadent.org.uk>
CommitDate: Sat, 25 Jul 2020 17:33:29 +0100
[klibc] sparc: Set sa_restorer for signals and disable executable stack
Add a __sigreturn stub and point sa_restorer to it by default, so
that the kernel doesn't create stack trampolines for signal return.
With that done, we no longer need an executable stack.
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
usr/include/arch/sparc/klibc/archconfig.h | 3 +++
usr/klibc/SYSCALLS.def | 2 +-
usr/klibc/arch/sparc/MCONFIG | 5 ++---
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/usr/include/arch/sparc/klibc/archconfig.h b/usr/include/arch/sparc/klibc/archconfig.h
index 70d5ef08..ab2c5fd7 100644
--- a/usr/include/arch/sparc/klibc/archconfig.h
+++ b/usr/include/arch/sparc/klibc/archconfig.h
@@ -12,4 +12,7 @@
#define _KLIBC_USE_RT_SIG 1 /* Use rt_* signals */
#define _KLIBC_SYS_SOCKETCALL 1 /* Use sys_socketcall unconditionally */
+/* So that we can avoid stack trampolines */
+#define _KLIBC_NEEDS_SA_RESTORER 1
+
#endif /* _KLIBC_ARCHCONFIG_H */
diff --git a/usr/klibc/SYSCALLS.def b/usr/klibc/SYSCALLS.def
index 16faabcb..0768df0d 100644
--- a/usr/klibc/SYSCALLS.def
+++ b/usr/klibc/SYSCALLS.def
@@ -212,7 +212,7 @@ ssize_t sendfile64,sendfile::sendfile(int, int, off_t *, size_t, off_t);
int rt_sigsuspend::__rt_sigsuspend(const sigset_t *, size_t);
int rt_sigpending::__rt_sigpending(sigset_t *, size_t);
int rt_sigprocmask::__rt_sigprocmask(int, const sigset_t *, sigset_t *, size_t);
-<sparc64> void rt_sigreturn::__sigreturn();
+<sparc,sparc64> void rt_sigreturn::__sigreturn();
#else
int sigaction::__sigaction(int, const struct sigaction *, struct sigaction *);
int sigpending(sigset_t *);
diff --git a/usr/klibc/arch/sparc/MCONFIG b/usr/klibc/arch/sparc/MCONFIG
index cabc7cd4..fb68ba3f 100644
--- a/usr/klibc/arch/sparc/MCONFIG
+++ b/usr/klibc/arch/sparc/MCONFIG
@@ -18,6 +18,5 @@ KLIBCARCHREQFLAGS += -D__sparc32__
# and call instructions have a 30-bit signed offset, << 2.
KLIBCSHAREDFLAGS = -Ttext-segment 0x40000000
-# Kernel uses stack trampoline for signal return unless we set
-# sa_restorer
-KLIBCEXECSTACK := y
+# Kernel uses our sa_restorer for signal return
+KLIBCEXECSTACK := n
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