diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/i386/i386/sys_machdep.c | 70 | ||||
| -rw-r--r-- | sys/i386/i386/vm_machdep.c | 3 |
2 files changed, 39 insertions, 34 deletions
diff --git a/sys/i386/i386/sys_machdep.c b/sys/i386/i386/sys_machdep.c index 31fad62..450018d 100644 --- a/sys/i386/i386/sys_machdep.c +++ b/sys/i386/i386/sys_machdep.c @@ -42,7 +42,6 @@ __FBSDID("$FreeBSD$"); #include <sys/mutex.h> #include <sys/priv.h> #include <sys/proc.h> -#include <sys/refcount.h> #include <sys/smp.h> #include <sys/sysproto.h> @@ -66,14 +65,15 @@ __FBSDID("$FreeBSD$"); #define NEW_MAX_LD(num) ((num + LD_PER_PAGE) & ~(LD_PER_PAGE-1)) #define SIZE_FROM_LARGEST_LD(num) (NEW_MAX_LD(num) << 3) +#ifdef SMP +#define NULL_LDT_BASE ((caddr_t)NULL) +static void set_user_ldt_rv(struct vmspace *vmsp); +#endif static int i386_set_ldt_data(struct thread *, int start, int num, union descriptor *descs); static int i386_ldt_grow(struct thread *td, int len); -#ifdef SMP -static void set_user_ldt_rv(struct thread *); -#endif #ifndef _SYS_SYSPROTO_H_ struct sysarch_args { @@ -378,10 +378,12 @@ set_user_ldt(struct mdproc *mdp) #ifdef SMP static void -set_user_ldt_rv(struct thread *td) +set_user_ldt_rv(struct vmspace *vmsp) { + struct thread *td; - if (td->td_proc != curthread->td_proc) + td = curthread; + if (vmsp != td->td_proc->p_vmspace) return; set_user_ldt(&td->td_proc->p_md); @@ -408,7 +410,7 @@ user_ldt_alloc(struct mdproc *mdp, int len) FREE(new_ldt, M_SUBPROC); return NULL; } - refcount_init(&new_ldt->ldt_refcnt, 1); + new_ldt->ldt_refcnt = 1; new_ldt->ldt_active = 0; mtx_lock_spin(&dt_lock); @@ -446,12 +448,13 @@ user_ldt_free(struct thread *td) } mdp->md_ldt = NULL; - mtx_unlock_spin(&dt_lock); - if (refcount_release(&pldt->ldt_refcnt)) { + if (--pldt->ldt_refcnt == 0) { + mtx_unlock_spin(&dt_lock); kmem_free(kernel_map, (vm_offset_t)pldt->ldt_base, pldt->ldt_len * sizeof(union descriptor)); FREE(pldt, M_SUBPROC); - } + } else + mtx_unlock_spin(&dt_lock); } /* @@ -690,9 +693,9 @@ static int i386_ldt_grow(struct thread *td, int len) { struct mdproc *mdp = &td->td_proc->p_md; - struct proc_ldt *pldt; - caddr_t old_ldt_base; - int old_ldt_len; + struct proc_ldt *new_ldt, *pldt; + caddr_t old_ldt_base = NULL_LDT_BASE; + int old_ldt_len = 0; mtx_assert(&dt_lock, MA_OWNED); @@ -703,29 +706,16 @@ i386_ldt_grow(struct thread *td, int len) /* Allocate a user ldt. */ if ((pldt = mdp->md_ldt) == NULL || len > pldt->ldt_len) { - struct proc_ldt *new_ldt; - new_ldt = user_ldt_alloc(mdp, len); if (new_ldt == NULL) return (ENOMEM); pldt = mdp->md_ldt; if (pldt != NULL) { - if (new_ldt->ldt_len > pldt->ldt_len) { - old_ldt_base = pldt->ldt_base; - old_ldt_len = pldt->ldt_len; - pldt->ldt_sd = new_ldt->ldt_sd; - pldt->ldt_base = new_ldt->ldt_base; - pldt->ldt_len = new_ldt->ldt_len; - mtx_unlock_spin(&dt_lock); - kmem_free(kernel_map, (vm_offset_t)old_ldt_base, - old_ldt_len * sizeof(union descriptor)); - FREE(new_ldt, M_SUBPROC); - mtx_lock_spin(&dt_lock); - } else { + if (new_ldt->ldt_len <= pldt->ldt_len) { /* - * If other threads already did the work, - * do nothing. + * We just lost the race for allocation, so + * free the new object and return. */ mtx_unlock_spin(&dt_lock); kmem_free(kernel_map, @@ -735,6 +725,16 @@ i386_ldt_grow(struct thread *td, int len) mtx_lock_spin(&dt_lock); return (0); } + + /* + * We have to substitute the current LDT entry for + * curproc with the new one since its size grew. + */ + old_ldt_base = pldt->ldt_base; + old_ldt_len = pldt->ldt_len; + pldt->ldt_sd = new_ldt->ldt_sd; + pldt->ldt_base = new_ldt->ldt_base; + pldt->ldt_len = new_ldt->ldt_len; } else mdp->md_ldt = pldt = new_ldt; #ifdef SMP @@ -746,11 +746,17 @@ i386_ldt_grow(struct thread *td, int len) */ mtx_unlock_spin(&dt_lock); smp_rendezvous(NULL, (void (*)(void *))set_user_ldt_rv, - NULL, td); - mtx_lock_spin(&dt_lock); + NULL, td->td_proc->p_vmspace); #else - set_user_ldt(mdp); + set_user_ldt(td); + mtx_unlock_spin(&dt_lock); #endif + if (old_ldt_base != NULL_LDT_BASE) { + kmem_free(kernel_map, (vm_offset_t)old_ldt_base, + old_ldt_len * sizeof(union descriptor)); + FREE(new_ldt, M_SUBPROC); + } + mtx_lock_spin(&dt_lock); } return (0); } diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index 48e19ae..bbcdddf 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -62,7 +62,6 @@ __FBSDID("$FreeBSD$"); #include <sys/mutex.h> #include <sys/pioctl.h> #include <sys/proc.h> -#include <sys/refcount.h> #include <sys/sf_buf.h> #include <sys/smp.h> #include <sys/sched.h> @@ -254,7 +253,7 @@ cpu_fork(td1, p2, td2, flags) mtx_lock_spin(&dt_lock); if (mdp2->md_ldt != NULL) { if (flags & RFMEM) { - refcount_acquire(&mdp2->md_ldt->ldt_refcnt); + mdp2->md_ldt->ldt_refcnt++; } else { mdp2->md_ldt = user_ldt_alloc(mdp2, mdp2->md_ldt->ldt_len); |
