OS-5322 lxbrand use comm page for vdso

Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Joshua M. Clulow <jmc@joyent.com>

manifest

@@ -5078,6 +5078,7 @@ f usr/lib/brand/lx/lx_boot_zone_ubuntu 0755 root root
 f usr/lib/brand/lx/lxinit 0755 root root
 f usr/lib/brand/lx/lx_librtld_db.so.1 0755 root root
 f usr/lib/brand/lx/lx_support 0755 root root
+f usr/lib/brand/lx/lx_vdso.so.1 0755 root root
 f usr/lib/brand/lx/platform.xml 0444 root root
 d usr/lib/brand/shared 0755 root sys
 f usr/lib/brand/shared/common.ksh 0444 root bin

usr/src/common/brand/lx/lx_auxv.c

@@ -37,14 +37,9 @@ lx_auxv_stol(const auxv_t *ap, auxv_t *oap, const lx_elf_data_t *edp)
 		oap->a_un.a_val = edp->ed_phnum;
 		break;
 	case AT_SUN_BRAND_LX_SYSINFO_EHDR:
-		if (edp->ed_vdso != 0) {
-			oap->a_type = AT_SYSINFO_EHDR;
-			oap->a_un.a_val = edp->ed_vdso;
-			return (0);
-		} else {
-			/* No vDSO for i386 */
-			return (1);
-		}
+		oap->a_type = AT_SYSINFO_EHDR;
+		oap->a_un.a_val = ap->a_un.a_val;
+		return (0);
 	case AT_SUN_BRAND_LX_CLKTCK:
 		oap->a_type = AT_CLKTCK;
 		oap->a_un.a_val = ap->a_un.a_val;

usr/src/lib/brand/lx/lx_brand/common/lx_brand.c

@@ -422,29 +422,6 @@ lx_close_fh(FILE *file)
 
 extern int set_l10n_alternate_root(char *path);
 
-#if defined(_LP64)
-static void *
-map_vdso()
-{
-	int fd;
-	mmapobj_result_t	mpp[10]; /* we know the size of our lib */
-	mmapobj_result_t	*smpp = mpp;
-	uint_t			mapnum = 10;
-
-	if ((fd = open("/native/usr/lib/brand/lx/amd64/lx_vdso.so.1",
-	    O_RDONLY)) == -1)
-		lx_err_fatal("couldn't open lx_vdso.so.1");
-
-	if (mmapobj(fd, MMOBJ_INTERPRET, smpp, &mapnum, NULL) == -1)
-		lx_err_fatal("couldn't mmapobj lx_vdso.so.1");
-
-	(void) close(fd);
-
-	/* assume first segment is the base of the mapping */
-	return (smpp->mr_addr);
-}
-#endif
-
 /*
  * Initialize the thread specific data for this thread.
  */
@@ -592,12 +569,8 @@ lx_init(int argc, char *argv[], char *envp[])
 	lx_elf_data_t	edp;
 	lx_brand_registration_t reg;
 	lx_tsd_t	*lxtsd;
-#if defined(_LP64)
-	void		*vdso_hdr;
-#endif
 
 	bzero(&reg, sizeof (reg));
-
 	stack_size = 2 * sysconf(_SC_PAGESIZE);
 
 	/*
@@ -686,18 +659,6 @@ lx_init(int argc, char *argv[], char *envp[])
 	if (lx_statfs_init() != 0)
 		lx_err_fatal("failed to setup the statfs translator");
 
-#if defined(_LP64)
-	vdso_hdr = map_vdso();
-	edp.ed_vdso = (uintptr_t)vdso_hdr;
-	/*
-	 * Notify the kernel of this mapping location to keep its
-	 * representation of the auxv consistent with reality.
-	 */
-	(void) syscall(SYS_brand, B_NOTIFY_VDSO_LOC, (void *)vdso_hdr);
-#else
-	edp.ed_vdso = 0;
-#endif
-
 	/*
 	 * Find the aux vector on the stack.
 	 */

usr/src/lib/brand/lx/lx_vdso/Makefile

@@ -10,17 +10,14 @@
 #
 
 #
-# Copyright 2015 Joyent, Inc.
+# Copyright 2016 Joyent, Inc.
 #
 
 include ../../../Makefile.lib
 
-SUBDIRS = tools
+SUBDIRS = tools $(MACH)
 $(BUILD64)SUBDIRS += $(MACH64)
 
-LINT_SUBDIRS = 
-$(BUILD64)LINT_SUBDIRS += $(MACH64)
-
 all :=          TARGET= all
 clean :=        TARGET= clean
 clobber :=      TARGET= clobber
@@ -33,6 +30,7 @@ all install clean clobber: $(SUBDIRS)
 
 lint: $(LINT_SUBDIRS)
 
+$(MACH): tools
 $(MACH64): tools
 
 $(SUBDIRS): FRC

usr/src/lib/brand/lx/lx_vdso/Makefile.com

@@ -10,14 +10,16 @@
 #
 
 #
-# Copyright 2015 Joyent, Inc.
+# Copyright 2016 Joyent, Inc.
 #
 
 LIBRARY	=	lx_vdso.a
 VERS =		.1
 
-COBJS =		lx_vdso.o
-OBJECTS =	$(COBJS)
+include $(SRC)/lib/commpage/Makefile.shared.com
+
+COBJS =		vdso_main.o vdso_subr.o
+OBJECTS =	$(COBJS) $(COMMPAGE_OBJS)
 
 include ../../../../Makefile.lib
 include ../../Makefile.lx
@@ -31,14 +33,15 @@ LIBNAME =	lx_vdso
 MAPFILES =	../common/mapfile-vers
 MAPOPTS =	$(MAPFILES:%=-M%)
 
-ASOBJS  =	lx_vdso.o
-OBJECTS =	$(ASOBJS)
-
-ASSRCS =	$(ASOBJS:%o=$(ISASRCDIR)/%s)
-SRCS =		$(ASSRCS)
+ASOBJS  =	vdso_subr.o
+COBJS  =	vdso_main.o
+OBJECTS =	$(ASOBJS) $(COBJS) $(COMMPAGE_OBJS)
 
 SRCDIR =	../common
-UTSBASE	=	../../../../../uts
+
+ASSRCS =	$(ASOBJS:%.o=$(ISASRCDIR)/%.s)
+CSRCS =		$(COBJS:%.o=$(SRCDIR)/%.c)
+SRCS =		$(ASSRCS) $(CSRCS)
 
 LIBS =		$(DYNLIB)
 DYNFLAGS +=	$(DYNFLAGS_$(CLASS))
@@ -72,7 +75,11 @@ all: $(LIBS)
 lint: $(LINTLIB) lintcheck
 
 include ../../../../Makefile.targ
+include $(SRC)/lib/commpage/Makefile.shared.targ
 
 pics/%.o: $(ISASRCDIR)/%.s
 	$(COMPILE.s) -o $@ $<
 	$(POST_PROCESS_O)
+
+pics/vdso_main.o := CPPFLAGS += $(COMMPAGE_CPPFLAGS)
+pics/vdso_subr.o := ASFLAGS += -I$(SRC)/uts/common/brand/lx

usr/src/lib/brand/lx/lx_vdso/amd64/Makefile

@@ -10,14 +10,19 @@
 #
 
 #
-# Copyright 2014 Joyent, Inc.  All rights reserved.
+# Copyright 2016 Joyent, Inc.
 #
 
 ISASRCDIR=.
+TARGET_ARCH=$(MACH64)
 
 include ../Makefile.com
 include $(SRC)/lib/Makefile.lib.64
 
+ASFLAGS += -D__$(MACH64)
+
+SONAME = linux-vdso.so.1
+
 #
 # You might ask, why aren't we overriding BUILD.SO in Makefile.com.
 # That's a sad story. The answer is that Makefile.lib.64 includes

usr/src/lib/brand/lx/lx_vdso/amd64/vdso_subr.s

@@ -0,0 +1,68 @@
+/*
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ */
+
+/*
+ * Copyright 2016 Joyent, Inc.
+ */
+
+
+#include <sys/asm_linkage.h>
+#include <sys/lx_syscalls.h>
+
+
+#if defined(lint)
+
+comm_page_t *
+__vdso_find_commpage()
+{}
+
+long
+__vdso_sys_clock_gettime(uint_t clock_id, timespec_t *tp)
+{}
+
+int
+__vdso_sys_gettimeofday(timespec_t *tp, struct lx_timezone *tz)
+{}
+
+time_t
+__vdso_sys_time(timespec_t *tp)
+{}
+
+#else /* lint */
+
+	ENTRY_NP(__vdso_find_commpage)
+	leaq	0x0(%rip), %rax
+	andq	$LX_VDSO_ADDR_MASK, %rax
+	addq	$LX_VDSO_SIZE, %rax
+	ret
+	SET_SIZE(__vdso_find_commpage)
+
+	ENTRY_NP(__vdso_sys_clock_gettime)
+	movl	$LX_SYS_clock_gettime, %eax
+	syscall
+	ret
+	SET_SIZE(__vdso_sys_clock_gettime)
+
+	ENTRY_NP(__vdso_sys_gettimeofday)
+	movl	$LX_SYS_gettimeofday, %eax
+	syscall
+	ret
+	SET_SIZE(__vdso_sys_gettimeofday)
+
+	ENTRY_NP(__vdso_sys_time)
+	movl	$LX_SYS_time, %eax
+	syscall
+	ret
+	SET_SIZE(__vdso_sys_time)
+
+#endif /* lint */