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| author | Andrea Arcangeli <andrea@cpushare.com> | 2007-07-15 23:41:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 09:05:50 -0700 |
| commit | 1d9d02feeee89e9132034d504c9a45eeaf618a3d (patch) | |
| tree | a4324cce8acd77cace3b1d4cf3a1e61783707e5c /kernel/seccomp.c | |
| parent | be0ef957c9eed4ebae873ee3fbcfb9dfde486dec (diff) | |
| download | lwn-1d9d02feeee89e9132034d504c9a45eeaf618a3d.tar.gz lwn-1d9d02feeee89e9132034d504c9a45eeaf618a3d.zip | |
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 <andrea@cpushare.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/seccomp.c')
| -rw-r--r-- | kernel/seccomp.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index c3391b6020e8..1dfa8a509726 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -10,6 +10,7 @@ #include <linux/sched.h> /* #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; +} |