Move the code dealing with shared page into a dedicated

kern_sharedpage.c source file from kern_exec.c.

MFC after:	  29 days

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();
+}