seccomp: ignore secure_computing return values

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>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This commit is contained in:
Will Drewry 2012-04-17 14:48:57 -05:00 committed by James Morris
parent b1fa650c7e
commit e4da89d02f
8 changed files with 14 additions and 7 deletions

View file

@ -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))

View file

@ -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;

View file

@ -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))

View file

@ -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

View file

@ -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))

View file

@ -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))

View file

@ -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);

View file

@ -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)
{