From 1d9d02feeee89e9132034d504c9a45eeaf618a3d Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Sun, 15 Jul 2007 23:41:32 -0700 Subject: move seccomp from /proc to a prctl This reduces the memory footprint and it enforces that only the current task can enable seccomp on itself (this is a requirement for a strightforward [modulo preempt ;) ] TIF_NOTSC implementation). Signed-off-by: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/seccomp.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'kernel/seccomp.c') diff --git a/kernel/seccomp.c b/kernel/seccomp.c index c3391b6020e..1dfa8a50972 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -10,6 +10,7 @@ #include /* #define SECCOMP_DEBUG 1 */ +#define NR_SECCOMP_MODES 1 /* * Secure computing mode 1 allows only read/write/exit/sigreturn. @@ -54,3 +55,28 @@ void __secure_computing(int this_syscall) #endif do_exit(SIGKILL); } + +long prctl_get_seccomp(void) +{ + return current->seccomp.mode; +} + +long prctl_set_seccomp(unsigned long seccomp_mode) +{ + long ret; + + /* can set it only once to be even more secure */ + ret = -EPERM; + if (unlikely(current->seccomp.mode)) + goto out; + + ret = -EINVAL; + if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) { + current->seccomp.mode = seccomp_mode; + set_thread_flag(TIF_SECCOMP); + ret = 0; + } + + out: + return ret; +} -- cgit v1.2.3