lkpi: allow late binding of linux_alloc_current

Some consumers may be loosely coupled with the lkpi.
This allows them to call linux_alloc_current without
having a static dependency.

Reviewed by:	hps@
MFC after:	1 week
Sponsored by:	iX Systems
Differential Revision:	https://reviews.freebsd.org/D19257
This commit is contained in:
Matt Macy 2019-02-22 23:15:32 +00:00
parent d97d43310c
commit 983ed4f9f1
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=344478
4 changed files with 21 additions and 4 deletions

View File

@ -41,18 +41,19 @@ struct task_struct;
extern int linux_alloc_current(struct thread *, int flags);
extern void linux_free_current(struct task_struct *);
static inline void
linux_set_current(struct thread *td)
{
if (__predict_false(td->td_lkpi_task == NULL))
linux_alloc_current(td, M_WAITOK);
lkpi_alloc_current(td, M_WAITOK);
}
static inline int
linux_set_current_flags(struct thread *td, int flags)
{
if (__predict_false(td->td_lkpi_task == NULL))
return (linux_alloc_current(td, flags));
return (lkpi_alloc_current(td, flags));
return (0);
}

View File

@ -218,6 +218,7 @@ linux_get_pid_task(pid_t pid)
static void
linux_current_init(void *arg __unused)
{
lkpi_alloc_current = linux_alloc_current;
linuxkpi_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
linuxkpi_thread_dtor, NULL, EVENTHANDLER_PRI_ANY);
}
@ -242,7 +243,7 @@ linux_current_uninit(void *arg __unused)
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
EVENTHANDLER_DEREGISTER(thread_dtor, linuxkpi_thread_dtor_tag);
lkpi_alloc_current = linux_alloc_current_noop;
}
SYSUNINIT(linux_current, SI_SUB_EVENTHANDLER, SI_ORDER_SECOND, linux_current_uninit, NULL);

View File

@ -107,6 +107,14 @@ struct thread0_storage thread0_st __aligned(32);
struct vmspace vmspace0;
struct proc *initproc;
int
linux_alloc_current_noop(struct thread *td __unused, int flags __unused)
{
return (0);
}
int (*lkpi_alloc_current)(struct thread *, int) = linux_alloc_current_noop;
#ifndef BOOTHOWTO
#define BOOTHOWTO 0
#endif
@ -454,7 +462,7 @@ proc0_init(void *dummy __unused)
GIANT_REQUIRED;
p = &proc0;
td = &thread0;
/*
* Initialize magic number and osrel.
*/

View File

@ -237,6 +237,13 @@ void init_param2(long physpages);
void init_static_kenv(char *, size_t);
void tablefull(const char *);
/*
* Allocate per-thread "current" state in the linuxkpi
*/
extern int (*lkpi_alloc_current)(struct thread *, int);
int linux_alloc_current_noop(struct thread *, int);
#if defined(KLD_MODULE) || defined(KTR_CRITICAL) || !defined(_KERNEL) || defined(GENOFFSET)
#define critical_enter() critical_enter_KBI()
#define critical_exit() critical_exit_KBI()