linux-kernel - Re: [RFC] making HAVE_SYSCALL_WRAPPERS universal (Re: Issues with "x86, um: switch to generic fork/vfork/clone" commit)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <50FE8A55.2000703@imgtec.com>
Date:	Tue, 22 Jan 2013 12:47:17 +0000
From:	James Hogan <james.hogan@...tec.com>
To:	Al Viro <viro@...IV.linux.org.uk>
CC:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Nicolas Dichtel <nicolas.dichtel@...nd.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	<linux-arch@...r.kernel.org>, Arnd Bergmann <arnd@...db.de>,
	Tony Luck <tony.luck@...el.com>
Subject: Re: [RFC] making HAVE_SYSCALL_WRAPPERS universal (Re: Issues with
 "x86, um: switch to generic fork/vfork/clone" commit)

On 21/01/13 22:55, Al Viro wrote:
> I've tried to sanitize cond_syscall/SYSCALL_ALIAS situation; the tree is in
> git.kernel.org/pub/scm/linux/kernel/git/viro/signal experimental-syscalls
> NOTE: this is absolutely untested and might very well blow up
> on any number of architectures.
> 
> Review and comments would be very welcome.

Looking at "consolidate cond_syscall and SYSCALL_ALIAS declarations",
is it worth having the default __SYMBOL_NAME declaration in
include/linux/linkage.h make use of CONFIG_SYMBOL_PREFIX?

E.g. in the metag patchset we currently have the patch below.

Admittedly CONFIG_SYMBOL_PREFIX is a string which would make it's use in
SYMBOL_NAME a bit awkward.

Cheers
James


Subject: [PATCH v3 02/44] asm-generic/unistd.h: handle symbol prefixes in
 cond_syscall

Some architectures have symbol prefixes and set CONFIG_SYMBOL_PREFIX,
but this wasn't taken into account by the generic cond_syscall. It's
easy enough to fix in a generic fashion, so add the symbol prefix to
symbol names in cond_syscall when CONFIG_SYMBOL_PREFIX is set.

Signed-off-by: James Hogan <james.hogan@...tec.com>
Acked-by: Arnd Bergmann <arnd@...db.de>
Acked-by: Mike Frysinger <vapier@...too.org>
---
 include/asm-generic/unistd.h |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 257c55e..4077b5d 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -17,5 +17,12 @@
  * but it doesn't work on all toolchains, so we just do it by hand
  */
 #ifndef cond_syscall
-#define cond_syscall(x) asm(".weak\t" #x "\n\t.set\t" #x ",sys_ni_syscall")
+#ifdef CONFIG_SYMBOL_PREFIX
+#define __SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
+#else
+#define __SYMBOL_PREFIX
+#endif
+#define cond_syscall(x) asm(".weak\t" __SYMBOL_PREFIX #x "\n\t" \
+			    ".set\t" __SYMBOL_PREFIX #x "," \
+			    __SYMBOL_PREFIX "sys_ni_syscall")
 #endif
-- 
1.7.7.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/