signal/seccomp: Refactor seccomp signal and coredump generation

Factor out force_sig_seccomp from the seccomp signal generation and
place it in kernel/signal.c.  The function force_sig_seccomp takes a
parameter force_coredump to indicate that the sigaction field should
be reset to SIGDFL so that a coredump will be generated when the
signal is delivered.

force_sig_seccomp is then used to replace both seccomp_send_sigsys
and seccomp_init_siginfo.

force_sig_info_to_task gains an extra parameter to force using
the default signal action.

With this change seccomp is no longer a special case and there
becomes exactly one place do_coredump is called from.

Further it no longer becomes necessary for __seccomp_filter
to call do_group_exit.

Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87r1gr6qc4.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index b9126fe06c3f..e3c933facd86 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -329,6 +329,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey);
 int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
 
 int force_sig_ptrace_errno_trap(int errno, void __user *addr);
+int force_sig_seccomp(int syscall, int reason, bool force_coredump);
 
 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
 extern void force_sigsegv(int sig);