linux-mips
[Top] [All Lists]

[PATCH 1/2] seccomp: ignore secure_computing return values

To: jmorris@namei.org
Subject: [PATCH 1/2] seccomp: ignore secure_computing return values
From: Will Drewry <wad@chromium.org>
Date: Tue, 17 Apr 2012 14:48:57 -0500
Cc: linux-kernel@vger.kernel.org, sfr@canb.auug.org.au, linux-security-module@vger.kernel.org, Will Drewry <wad@chromium.org>, Michal Simek <monstr@monstr.eu>, Ralf Baechle <ralf@linux-mips.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, linux390@de.ibm.com, Paul Mundt <lethal@linux-sh.org>, "David S. Miller" <davem@davemloft.net>, Eric Paris <eparis@redhat.com>, Richard Weinberger <richard@nod.at>, David Howells <dhowells@redhat.com>, Ingo Molnar <mingo@elte.hu>, Frederic Weisbecker <fweisbec@gmail.com>, Peter Zijlstra <a.p.zijlstra@chello.nl>, "H. Peter Anvin" <hpa@zytor.com>, Avi Kivity <avi@redhat.com>, Tony Luck <tony.luck@intel.com>, James Morris <james.l.morris@oracle.com>, Serge Hallyn <serge.hallyn@canonical.com>, Kees Cook <keescook@chromium.org>, microblaze-uclinux@itee.uq.edu.au, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:x-mailer; bh=8242z81rj4K9wM0lnlYOF+4SYShWucsRygbDwGwRaQA=; b=O10Mr+PUzdG79eTGVs6uV2xL5E6Cf+XZ8oIDyJpebU3buKEr3ifvOu/KKVGErhlGxw wOHNySsVhykJO6kgJyCoNnftQRLH4zOi91D90cxokYbdQQMhauNSzmdD0QOiAQIuUErv ZGgPw1GMq6e+WGiu3YY+l5+kbK5CVjaIPMrUI=
Sender: linux-mips-bounce@linux-mips.org
This change is inspired by
  https://lkml.org/lkml/2012/4/16/14
which fixes the build warnings for arches that don't support
CONFIG_HAVE_ARCH_SECCOMP_FILTER.

In particular, there is no requirement for the return value of
secure_computing() to be checked unless the architecture supports
seccomp filter.  Instead of silencing the warnings with (void)
a new static inline is added to encode the expected behavior
in a compiler and human friendly way.

v2: - cleans things up with a static inline
    - removes sfr's signed-off-by since it is a different approach
v1: - matches sfr's original change

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
---
 arch/microblaze/kernel/ptrace.c |    2 +-
 arch/mips/kernel/ptrace.c       |    2 +-
 arch/powerpc/kernel/ptrace.c    |    2 +-
 arch/s390/kernel/ptrace.c       |    2 +-
 arch/sh/kernel/ptrace_32.c      |    2 +-
 arch/sh/kernel/ptrace_64.c      |    2 +-
 arch/sparc/kernel/ptrace_64.c   |    2 +-
 include/linux/seccomp.h         |    7 +++++++
 8 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
index 6eb2aa9..ab1b9db 100644
--- a/arch/microblaze/kernel/ptrace.c
+++ b/arch/microblaze/kernel/ptrace.c
@@ -136,7 +136,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
        long ret = 0;
 
-       secure_computing(regs->r12);
+       secure_computing_strict(regs->r12);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
            tracehook_report_syscall_entry(regs))
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 7c24c29..4812c6d 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -535,7 +535,7 @@ static inline int audit_arch(void)
 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 {
        /* do the secure computing check first */
-       secure_computing(regs->regs[2]);
+       secure_computing_strict(regs->regs[2]);
 
        if (!(current->ptrace & PT_PTRACED))
                goto out;
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8d8e028..dd5e214 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1710,7 +1710,7 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 {
        long ret = 0;
 
-       secure_computing(regs->gpr[0]);
+       secure_computing_strict(regs->gpr[0]);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
            tracehook_report_syscall_entry(regs))
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 02f300f..4993e68 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -719,7 +719,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
        long ret = 0;
 
        /* Do the secure computing check first. */
-       secure_computing(regs->gprs[2]);
+       secure_computing_strict(regs->gprs[2]);
 
        /*
         * The sysc_tracesys code in entry.S stored the system
diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index 9698671..81f999a 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -503,7 +503,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
        long ret = 0;
 
-       secure_computing(regs->regs[0]);
+       secure_computing_strict(regs->regs[0]);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
            tracehook_report_syscall_entry(regs))
diff --git a/arch/sh/kernel/ptrace_64.c b/arch/sh/kernel/ptrace_64.c
index bc81e07..af90339 100644
--- a/arch/sh/kernel/ptrace_64.c
+++ b/arch/sh/kernel/ptrace_64.c
@@ -522,7 +522,7 @@ asmlinkage long long do_syscall_trace_enter(struct pt_regs 
*regs)
 {
        long long ret = 0;
 
-       secure_computing(regs->regs[9]);
+       secure_computing_strict(regs->regs[9]);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
            tracehook_report_syscall_entry(regs))
diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c
index 6f97c07..484daba 100644
--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -1062,7 +1062,7 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs)
        int ret = 0;
 
        /* do the secure computing check first */
-       secure_computing(regs->u_regs[UREG_G1]);
+       secure_computing_strict(regs->u_regs[UREG_G1]);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE))
                ret = tracehook_report_syscall_entry(regs);
diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h
index 60f2b35..84f6320d 100644
--- a/include/linux/seccomp.h
+++ b/include/linux/seccomp.h
@@ -75,6 +75,12 @@ static inline int secure_computing(int this_syscall)
        return 0;
 }
 
+/* A wrapper for architectures supporting only SECCOMP_MODE_STRICT. */
+static inline void secure_computing_strict(int this_syscall)
+{
+       BUG_ON(secure_computing(this_syscall) != 0);
+}
+
 extern long prctl_get_seccomp(void);
 extern long prctl_set_seccomp(unsigned long, char __user *);
 
@@ -91,6 +97,7 @@ struct seccomp { };
 struct seccomp_filter { };
 
 static inline int secure_computing(int this_syscall) { return 0; }
+static inline void secure_computing_strict(int this_syscall) { return; }
 
 static inline long prctl_get_seccomp(void)
 {
-- 
1.7.5.4


<Prev in Thread] Current Thread [Next in Thread>
  • [PATCH 1/2] seccomp: ignore secure_computing return values, Will Drewry <=