Commit ca86b5dc authored Nov 07, 2012 by Al Viro

new helper: get_signal()



On success get_signal_to_deliver() fills k_sigaction and siginfo.
_All_ users pass it addresses of the local variables sitting in
the same function.  Then they proceed to pass those addresses
pretty much in tandem to a bunch of helper functions; again, all
callers of those helpers are passing them such a pair, and one that
had been through get_signal_to_deliver() at that.

The obvious cleanup: introduce a new type that would contain a
<k_sigaction,siginfo> pair (struct ksignal) and begin switching to
using it.  Turns out that it's convenient to store the signal number
in the same object.

New helper, taking that sucker is a wrapper for get_signal_to_deliver();
takes struct ksignal * and returns bool.  On success fills ksignal
with the information for signal handler to be invoked.

For now it's a macro (to avoid header ordering headache), but eventually
it'll be a function in kernel/signal.c, with get_signal_to_deliver()
folded into it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 9d94b9e2

include/linux/signal.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -279,10 +279,28 @@ struct old_sigaction {
		};
		#endif

		struct ksignal {
		struct k_sigaction ka;
		siginfo_t info;
		int sig;
		};

		extern int get_signal_to_deliver(siginfo_t info, struct k_sigaction return_ka, struct pt_regs regs, void cookie);
		extern void signal_delivered(int sig, siginfo_t info, struct k_sigaction ka, struct pt_regs *regs, int stepping);
		extern void exit_signals(struct task_struct *tsk);

		/*
		* Eventually that'll replace get_signal_to_deliver(); macro for now,
		* to avoid nastiness with include order.
		*/
		#define get_signal(ksig) \
		({ \
		struct ksignal *p = (ksig); \
		p->sig = get_signal_to_deliver(&p->info, &p->ka, \
		signal_pt_regs(), NULL);\
		p->sig > 0; \
		})

		extern struct kmem_cache *sighand_cachep;

		int unhandled_signal(struct task_struct *tsk, int sig);