diff options
Diffstat (limited to 'sys/kern/kern_sharedpage.c')
| -rw-r--r-- | sys/kern/kern_sharedpage.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/sys/kern/kern_sharedpage.c b/sys/kern/kern_sharedpage.c new file mode 100644 index 0000000..619304a --- /dev/null +++ b/sys/kern/kern_sharedpage.c @@ -0,0 +1,240 @@ +/*- + * Copyright (c) 2010, 2012 Konstantin Belousov <kib@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_compat.h" +#include "opt_vm.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/sysent.h> +#include <sys/sysctl.h> +#include <sys/vdso.h> + +#include <vm/vm.h> +#include <vm/vm_param.h> +#include <vm/pmap.h> +#include <vm/vm_extern.h> +#include <vm/vm_kern.h> +#include <vm/vm_map.h> +#include <vm/vm_object.h> +#include <vm/vm_page.h> +#include <vm/vm_pager.h> + +static struct sx shared_page_alloc_sx; +static vm_object_t shared_page_obj; +static int shared_page_free; +char *shared_page_mapping; + +void +shared_page_write(int base, int size, const void *data) +{ + + bcopy(data, shared_page_mapping + base, size); +} + +static int +shared_page_alloc_locked(int size, int align) +{ + int res; + + res = roundup(shared_page_free, align); + if (res + size >= IDX_TO_OFF(shared_page_obj->size)) + res = -1; + else + shared_page_free = res + size; + return (res); +} + +int +shared_page_alloc(int size, int align) +{ + int res; + + sx_xlock(&shared_page_alloc_sx); + res = shared_page_alloc_locked(size, align); + sx_xunlock(&shared_page_alloc_sx); + return (res); +} + +int +shared_page_fill(int size, int align, const void *data) +{ + int res; + + sx_xlock(&shared_page_alloc_sx); + res = shared_page_alloc_locked(size, align); + if (res != -1) + shared_page_write(res, size, data); + sx_xunlock(&shared_page_alloc_sx); + return (res); +} + +static void +shared_page_init(void *dummy __unused) +{ + vm_page_t m; + vm_offset_t addr; + + sx_init(&shared_page_alloc_sx, "shpsx"); + shared_page_obj = vm_pager_allocate(OBJT_PHYS, 0, PAGE_SIZE, + VM_PROT_DEFAULT, 0, NULL); + VM_OBJECT_LOCK(shared_page_obj); + m = vm_page_grab(shared_page_obj, 0, VM_ALLOC_RETRY | VM_ALLOC_NOBUSY | + VM_ALLOC_ZERO); + m->valid = VM_PAGE_BITS_ALL; + VM_OBJECT_UNLOCK(shared_page_obj); + addr = kmem_alloc_nofault(kernel_map, PAGE_SIZE); + pmap_qenter(addr, &m, 1); + shared_page_mapping = (char *)addr; +} + +SYSINIT(shp, SI_SUB_EXEC, SI_ORDER_FIRST, (sysinit_cfunc_t)shared_page_init, + NULL); + +static void +timehands_update(struct sysentvec *sv) +{ + struct vdso_timehands th; + struct vdso_timekeep *tk; + uint32_t enabled, idx; + + enabled = tc_fill_vdso_timehands(&th); + tk = (struct vdso_timekeep *)(shared_page_mapping + + sv->sv_timekeep_off); + idx = sv->sv_timekeep_curr; + atomic_store_rel_32(&tk->tk_th[idx].th_gen, 0); + if (++idx >= VDSO_TH_NUM) + idx = 0; + sv->sv_timekeep_curr = idx; + if (++sv->sv_timekeep_gen == 0) + sv->sv_timekeep_gen = 1; + th.th_gen = 0; + if (enabled) + tk->tk_th[idx] = th; + tk->tk_enabled = enabled; + atomic_store_rel_32(&tk->tk_th[idx].th_gen, sv->sv_timekeep_gen); + tk->tk_current = idx; +} + +#ifdef COMPAT_FREEBSD32 +static void +timehands_update32(struct sysentvec *sv) +{ + struct vdso_timekeep32 *tk; + struct vdso_timehands32 th; + uint32_t enabled, idx; + + enabled = tc_fill_vdso_timehands32(&th); + tk = (struct vdso_timekeep32 *)(shared_page_mapping + + sv->sv_timekeep_off); + idx = sv->sv_timekeep_curr; + atomic_store_rel_32(&tk->tk_th[idx].th_gen, 0); + if (++idx >= VDSO_TH_NUM) + idx = 0; + sv->sv_timekeep_curr = idx; + if (++sv->sv_timekeep_gen == 0) + sv->sv_timekeep_gen = 1; + th.th_gen = 0; + if (enabled) + tk->tk_th[idx] = th; + tk->tk_enabled = enabled; + atomic_store_rel_32(&tk->tk_th[idx].th_gen, sv->sv_timekeep_gen); + tk->tk_current = idx; +} +#endif + +/* + * This is hackish, but easiest way to avoid creating list structures + * that needs to be iterated over from the hardclock interrupt + * context. + */ +static struct sysentvec *host_sysentvec; +#ifdef COMPAT_FREEBSD32 +static struct sysentvec *compat32_sysentvec; +#endif + +void +timekeep_push_vdso(void) +{ + + if (host_sysentvec != NULL && host_sysentvec->sv_timekeep_base != 0) + timehands_update(host_sysentvec); +#ifdef COMPAT_FREEBSD32 + if (compat32_sysentvec != NULL && + compat32_sysentvec->sv_timekeep_base != 0) + timehands_update32(compat32_sysentvec); +#endif +} + +void +exec_sysvec_init(void *param) +{ + struct sysentvec *sv; + int tk_base; + uint32_t tk_ver; + + sv = (struct sysentvec *)param; + + if ((sv->sv_flags & SV_SHP) == 0) + return; + sv->sv_shared_page_obj = shared_page_obj; + sv->sv_sigcode_base = sv->sv_shared_page_base + + shared_page_fill(*(sv->sv_szsigcode), 16, sv->sv_sigcode); + if ((sv->sv_flags & SV_ABI_MASK) != SV_ABI_FREEBSD) + return; + tk_ver = VDSO_TK_VER_CURR; +#ifdef COMPAT_FREEBSD32 + if ((sv->sv_flags & SV_ILP32) != 0) { + tk_base = shared_page_alloc(sizeof(struct vdso_timekeep32) + + sizeof(struct vdso_timehands32) * VDSO_TH_NUM, 16); + KASSERT(tk_base != -1, ("tk_base -1 for 32bit")); + shared_page_write(tk_base + offsetof(struct vdso_timekeep32, + tk_ver), sizeof(uint32_t), &tk_ver); + KASSERT(compat32_sysentvec == 0, + ("Native compat32 already registered")); + compat32_sysentvec = sv; + } else { +#endif + tk_base = shared_page_alloc(sizeof(struct vdso_timekeep) + + sizeof(struct vdso_timehands) * VDSO_TH_NUM, 16); + KASSERT(tk_base != -1, ("tk_base -1 for native")); + shared_page_write(tk_base + offsetof(struct vdso_timekeep, + tk_ver), sizeof(uint32_t), &tk_ver); + KASSERT(host_sysentvec == 0, ("Native already registered")); + host_sysentvec = sv; +#ifdef COMPAT_FREEBSD32 + } +#endif + sv->sv_timekeep_base = sv->sv_shared_page_base + tk_base; + sv->sv_timekeep_off = tk_base; + timekeep_push_vdso(); +} |
