Uninline find_pid etc set of functions (8990571e) · Commits · 戴 / test

The find_pid/_vpid/_pid_ns functions are used to find the struct pid by its id, depending on whic id - global or virtual - is used. The find_vpid() is a macro that pushes the current->nsproxy->pid_ns on the stack to call another function - find_pid_ns(). It turned out, that this dereference together with the push itself cause the kernel text size to grow too much. Move all these out-of-line. Together with the previous patch this saves a bit less that 400 bytes from .text section. Signed-off-by:

Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

include/linux/pid.h

+2 −3

Original line number	Diff line number	Diff line
		@@ -110,9 +110,8 @@ extern struct pid_namespace init_pid_ns;
		* see also find_task_by_pid() set in include/linux/sched.h
		*/
		extern struct pid FASTCALL(find_pid_ns(int nr, struct pid_namespace ns));

		#define find_vpid(pid) find_pid_ns(pid, current->nsproxy->pid_ns)
		#define find_pid(pid) find_pid_ns(pid, &init_pid_ns)
		extern struct pid *find_vpid(int nr);
		extern struct pid *find_pid(int nr);

		/*
		* Lookup a PID in the hash table, and return with it's count elevated.

kernel/capability.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -96,7 +96,7 @@ static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
		int found = 0;
		struct pid *pgrp;

		pgrp = find_pid_ns(pgrp_nr, current->nsproxy->pid_ns);
		pgrp = find_vpid(pgrp_nr);
		do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
		target = g;
		while_each_thread(g, target) {

kernel/pid.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -302,6 +302,18 @@ struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns)
		}
		EXPORT_SYMBOL_GPL(find_pid_ns);

		struct pid *find_vpid(int nr)
		{
		return find_pid_ns(nr, current->nsproxy->pid_ns);
		}
		EXPORT_SYMBOL_GPL(find_vpid);

		struct pid *find_pid(int nr)
		{
		return find_pid_ns(nr, &init_pid_ns);
		}
		EXPORT_SYMBOL_GPL(find_pid);

		/*
		* attach_pid() must be called with the tasklist_lock write-held.
		*/

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