OS-4571 lxbrand allow manipulation of uname release and version

Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

13 files changed, 253 insertions, 129 deletions

diff --git a/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c b/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c
index 2f9d7930b3..cdc556459e 100644
--- a/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c
+++ b/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c
@@ -87,7 +87,7 @@
  * function should return -errno back to the Linux caller.
  */
 
-char lx_release[LX_VERS_MAX];
+char lx_release[LX_KERN_RELEASE_MAX];
 char lx_cmd_name[MAXNAMLEN];
 
 /*
@@ -545,7 +545,7 @@ lx_start(uintptr_t sp, uintptr_t entry)
 int
 lx_init(int argc, char *argv[], char *envp[])
 {
-	char		*r;
+	char		*rele, *vers;
 	auxv_t		*ap;
 	long		*p;
 	int		err;
@@ -572,17 +572,23 @@ lx_init(int argc, char *argv[], char *envp[])
 
 	lx_debug_init();
 
-	r = getenv("LX_RELEASE");
-	if (r == NULL) {
-		if (zone_getattr(getzoneid(), LX_KERN_VERSION_NUM, lx_release,
-		    sizeof (lx_release)) != sizeof (lx_release))
-			(void) strlcpy(lx_release, "2.4.21", LX_VERS_MAX);
+	rele = getenv("LX_RELEASE");
+	vers = getenv("LX_VERSION");
+	if (rele == NULL) {
+		if (zone_getattr(getzoneid(), LX_ATTR_KERN_RELEASE,
+		    lx_release, sizeof (lx_release)) <= 0)
+			(void) strlcpy(lx_release, "2.4.21",
+			    LX_KERN_RELEASE_MAX);
 	} else {
-		(void) strlcpy(lx_release, r, 128);
+		(void) strlcpy(lx_release, rele, LX_KERN_RELEASE_MAX);
 	}
 
+	if (syscall(SYS_brand, B_OVERRIDE_KERN_VER, rele, vers) != 0) {
+		lx_debug("failed to override kernel release/version");
+	}
 	lx_debug("lx_release: %s\n", lx_release);
 
+
 	/*
 	 * Should we kill an application that attempts an unimplemented
 	 * system call?
@@ -977,7 +983,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_exit,			/*  60: exit */
 	NULL,				/*  61: wait4 */
 	NULL,				/*  62: kill */
-	lx_uname,			/*  63: uname */
+	NULL,				/*  63: uname */
 	lx_semget,			/*  64: semget */
 	lx_semop,			/*  65: semop */
 	lx_semctl,			/*  66: semctl */
@@ -1367,7 +1373,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_sigreturn,			/* 119: sigreturn */
 	lx_clone,			/* 120: clone */
 	lx_setdomainname,		/* 121: setdomainname */
-	lx_uname,			/* 122: uname */
+	NULL,				/* 122: uname */
 	NULL,				/* 123: modify_ldt */
 	lx_adjtimex,			/* 124: adjtimex */
 	lx_mprotect,			/* 125: mprotect */
diff --git a/usr/src/lib/brand/lx/lx_brand/common/misc.c b/usr/src/lib/brand/lx/lx_brand/common/misc.c
index f56b9e8905..03a6df70dd 100644
--- a/usr/src/lib/brand/lx/lx_brand/common/misc.c
+++ b/usr/src/lib/brand/lx/lx_brand/common/misc.c
@@ -229,27 +229,6 @@ lx_getcwd(uintptr_t p1, uintptr_t p2)
 	return (len + 1);
 }
 
-long
-lx_uname(uintptr_t p1)
-{
-	struct lx_utsname *un = (struct lx_utsname *)p1;
-	char buf[LX_SYS_UTS_LN + 1];
-
-	if (gethostname(un->nodename, sizeof (un->nodename)) == -1)
-		return (-errno);
-
-	(void) strlcpy(un->sysname, LX_UNAME_SYSNAME, LX_SYS_UTS_LN);
-	(void) strlcpy(un->release, lx_release, LX_SYS_UTS_LN);
-	(void) strlcpy(un->version, LX_UNAME_VERSION, LX_SYS_UTS_LN);
-	(void) strlcpy(un->machine, LX_UNAME_MACHINE, LX_SYS_UTS_LN);
-	if ((sysinfo(SI_SRPC_DOMAIN, buf, LX_SYS_UTS_LN) < 0))
-		un->domainname[0] = '\0';
-	else
-		(void) strlcpy(un->domainname, buf, LX_SYS_UTS_LN);
-
-	return (0);
-}
-
 /*
  * {get,set}groups16() - Handle the conversion between 16-bit Linux gids and
  * 32-bit illumos gids.
diff --git a/usr/src/lib/brand/lx/lx_brand/sys/lx_misc.h b/usr/src/lib/brand/lx/lx_brand/sys/lx_misc.h
index 6f1b772228..05a38a0788 100644
--- a/usr/src/lib/brand/lx/lx_brand/sys/lx_misc.h
+++ b/usr/src/lib/brand/lx/lx_brand/sys/lx_misc.h
@@ -47,7 +47,7 @@
 extern "C" {
 #endif
 
-extern char lx_release[LX_VERS_MAX];
+extern char lx_release[LX_KERN_RELEASE_MAX];
 extern char lx_cmd_name[MAXNAMLEN];
 extern pid_t zoneinit_pid;
 
diff --git a/usr/src/lib/brand/lx/lx_support/lx_support.c b/usr/src/lib/brand/lx/lx_support/lx_support.c
index d1f96defb5..f4e1a23da0 100644
--- a/usr/src/lib/brand/lx/lx_support/lx_support.c
+++ b/usr/src/lib/brand/lx/lx_support/lx_support.c
@@ -60,8 +60,6 @@ static void usage(void) __NORETURN;
 #define	CP_CMD		"/usr/bin/cp"
 #define	MOUNT_CMD	"/sbin/mount"
 
-#define	KVSTRLEN		10
-
 static char *bname = NULL;
 static char *zonename = NULL;
 static char *zoneroot = NULL;
@@ -175,7 +173,7 @@ lxs_remove_autofsck()
  * Extract any lx-supported attributes from the zone configuration file.
  */
 static void
-lxs_getattrs(zone_dochandle_t zdh, char **kvers)
+lxs_getattrs(zone_dochandle_t zdh, char **krelease)
 {
 	struct zone_attrtab	attrtab;
 	int			err;
@@ -186,22 +184,22 @@ lxs_getattrs(zone_dochandle_t zdh, char **kvers)
 		lxs_err(gettext("error accessing zone configuration"));
 	}
 
-	*kvers = (char *)malloc(KVSTRLEN);
-	if (*kvers == NULL)
+	*krelease = (char *)malloc(LX_KERN_RELEASE_MAX);
+	if (*krelease == NULL)
 		lxs_err(gettext("out of memory"));
 
-	bzero(*kvers, KVSTRLEN);
+	bzero(*krelease, LX_KERN_RELEASE_MAX);
 	while ((err = zonecfg_getattrent(zdh, &attrtab)) == Z_OK) {
 		if ((strcmp(attrtab.zone_attr_name, "kernel-version") == 0) &&
-		    (zonecfg_get_attr_string(&attrtab, *kvers,
-		    KVSTRLEN) != Z_OK))
+		    (zonecfg_get_attr_string(&attrtab, *krelease,
+		    LX_KERN_RELEASE_MAX) != Z_OK))
 			lxs_err(gettext("invalid type for zone attribute: %s"),
 			    attrtab.zone_attr_name);
 	}
 
-	if (strlen(*kvers) == 0) {
-		free(*kvers);
-		*kvers = NULL;
+	if (strlen(*krelease) == 0) {
+		free(*krelease);
+		*krelease = NULL;
 	}
 
 	/* some kind of error while looking up attributes */
@@ -214,7 +212,7 @@ lxs_boot()
 {
 	zoneid_t	zoneid;
 	zone_dochandle_t zdh;
-	char		*kvers;
+	char		*krelease;
 
 	lxs_make_initctl();
 	lxs_remove_autofsck();
@@ -228,7 +226,7 @@ lxs_boot()
 	}
 
 	/* Extract any relevant attributes from the config file. */
-	lxs_getattrs(zdh, &kvers);
+	lxs_getattrs(zdh, &krelease);
 	zonecfg_fini_handle(zdh);
 
 	/*
@@ -238,16 +236,16 @@ lxs_boot()
 	if ((zoneid = getzoneidbyname(zonename)) < 0)
 		lxs_err(gettext("unable to get zoneid"));
 
-	if (kvers != NULL) {
+	if (krelease != NULL) {
 		/* Backward compatability with incomplete version attr */
-		if (strcmp(kvers, "2.4") == 0) {
-			kvers = "2.4.21";
-		} else if (strcmp(kvers, "2.6") == 0) {
-			kvers = "2.6.18";
+		if (strcmp(krelease, "2.4") == 0) {
+			krelease = "2.4.21";
+		} else if (strcmp(krelease, "2.6") == 0) {
+			krelease = "2.6.18";
 		}
 
-		if (zone_setattr(zoneid, LX_KERN_VERSION_NUM, kvers,
-		    strlen(kvers)) < 0)
+		if (zone_setattr(zoneid, LX_ATTR_KERN_RELEASE, krelease,
+		    strlen(krelease)) < 0)
 			lxs_err(gettext("unable to set kernel version"));
 	}
 
@@ -264,7 +262,7 @@ static int
 lxs_verify(char *xmlfile)
 {
 	zone_dochandle_t	handle;
-	char			*kvers;
+	char			*krelease;
 	char			hostidp[HW_HOSTID_LEN];
 	zone_iptype_t		iptype;
 
@@ -294,14 +292,14 @@ lxs_verify(char *xmlfile)
 	}
 
 	/* Extract any relevant attributes from the config file. */
-	lxs_getattrs(handle, &kvers);
+	lxs_getattrs(handle, &krelease);
 	zonecfg_fini_handle(handle);
 
-	if (kvers) {
-		if (strlen(kvers) > (LX_VERS_MAX - 1) ||
-		    (strncmp(kvers, "2.4", 3) != 0 &&
-		    strncmp(kvers, "2.6", 3) != 0 &&
-		    strncmp(kvers, "3.", 2) != 0))
+	if (krelease) {
+		if (strlen(krelease) >= LX_KERN_RELEASE_MAX ||
+		    (strncmp(krelease, "2.4", 3) != 0 &&
+		    strncmp(krelease, "2.6", 3) != 0 &&
+		    strncmp(krelease, "3.", 2) != 0))
 			lxs_err(gettext("invalid value for zone attribute: %s"),
 			    "kernel-version");
 	}
diff --git a/usr/src/uts/common/brand/lx/io/lx_netlink.c b/usr/src/uts/common/brand/lx/io/lx_netlink.c
index 2e80e1bf11..36b0cf9b2b 100644
--- a/usr/src/uts/common/brand/lx/io/lx_netlink.c
+++ b/usr/src/uts/common/brand/lx/io/lx_netlink.c
@@ -1239,7 +1239,7 @@ lx_netlink_getroute(lx_netlink_sock_t *lxsock, lx_netlink_hdr_t *hdr,
 	 * truncate our input to prevent later confusion.
 	 */
 	if (curproc->p_zone->zone_brand == &lx_brand &&
-	    lx_kern_version_cmp(curproc->p_zone, "2.6.32") <= 0 &&
+	    lx_kern_release_cmp(curproc->p_zone, "2.6.32") <= 0 &&
 	    rtmsgp->rtm_dst_len == 0) {
 		rtmsg_size = sizeof (rtmsg.rtm_family);
 	}
diff --git a/usr/src/uts/common/brand/lx/os/lx_brand.c b/usr/src/uts/common/brand/lx/os/lx_brand.c
index 44acdff3b1..5dc026a21e 100644
--- a/usr/src/uts/common/brand/lx/os/lx_brand.c
+++ b/usr/src/uts/common/brand/lx/os/lx_brand.c
@@ -364,36 +364,77 @@ lx_setbrand(proc_t *p)
 
 /* ARGSUSED */
 int
-lx_setattr(zone_t *zone, int attr, void *buf, size_t bufsize)
+lx_setattr(zone_t *zone, int attr, void *ubuf, size_t ubufsz)
 {
-	char vers[LX_VERS_MAX];
+	lx_zone_data_t *lxzd = (lx_zone_data_t *)zone->zone_brand_data;
 
-	if (attr == LX_KERN_VERSION_NUM) {
-		if (bufsize > (LX_VERS_MAX - 1))
+	switch (attr) {
+	case LX_ATTR_KERN_RELEASE: {
+		char buf[LX_KERN_RELEASE_MAX];
+		bzero(buf, LX_KERN_RELEASE_MAX);
+		if (ubufsz >= LX_KERN_RELEASE_MAX) {
 			return (ERANGE);
-		bzero(vers, LX_VERS_MAX);
-		if (copyin(buf, &vers, bufsize) != 0)
+		}
+		if (copyin(ubuf, buf, ubufsz) != 0) {
 			return (EFAULT);
-		lx_set_kern_version(zone, vers);
+		}
+		(void) strlcpy(lxzd->lxzd_kernel_release, buf,
+		    LX_KERN_RELEASE_MAX);
 		return (0);
 	}
-	return (EINVAL);
+	case LX_ATTR_KERN_VERSION: {
+		char buf[LX_KERN_VERSION_MAX];
+		bzero(buf, LX_KERN_VERSION_MAX);
+		if (ubufsz >= LX_KERN_VERSION_MAX) {
+			return (ERANGE);
+		}
+		if (copyin(ubuf, buf, ubufsz) != 0) {
+			return (EFAULT);
+		}
+		(void) strlcpy(lxzd->lxzd_kernel_version, buf,
+		    LX_KERN_VERSION_MAX);
+		return (0);
+	}
+	default:
+		return (EINVAL);
+	}
 }
 
 /* ARGSUSED */
 int
-lx_getattr(zone_t *zone, int attr, void *buf, size_t *bufsize)
+lx_getattr(zone_t *zone, int attr, void *ubuf, size_t *ubufsz)
 {
-	if (attr == LX_KERN_VERSION_NUM) {
-		if (*bufsize < LX_VERS_MAX)
+	lx_zone_data_t *lxzd = (lx_zone_data_t *)zone->zone_brand_data;
+	int len;
+
+	switch (attr) {
+	case LX_ATTR_KERN_RELEASE: {
+		len = strnlen(lxzd->lxzd_kernel_release, LX_KERN_RELEASE_MAX);
+		len++;
+		if (*ubufsz < len) {
 			return (ERANGE);
-		if (copyout(lx_get_zone_kern_version(curzone), buf,
-		    LX_VERS_MAX) != 0)
+		}
+		if (copyout(lxzd->lxzd_kernel_release, ubuf, len) != 0) {
 			return (EFAULT);
-		*bufsize = LX_VERS_MAX;
+		}
+		*ubufsz = len;
 		return (0);
 	}
-	return (-EINVAL);
+	case LX_ATTR_KERN_VERSION: {
+		len = strnlen(lxzd->lxzd_kernel_version, LX_KERN_VERSION_MAX);
+		len++;
+		if (*ubufsz < len) {
+			return (ERANGE);
+		}
+		if (copyout(lxzd->lxzd_kernel_version, ubuf, len) != 0) {
+			return (EFAULT);
+		}
+		*ubufsz = len;
+		return (0);
+	}
+	default:
+		return (EINVAL);
+	}
 }
 
 uint32_t
@@ -725,7 +766,10 @@ lx_init_brand_data(zone_t *zone)
 	 * Set the default lxzd_kernel_version to 2.4.
 	 * This can be changed by a call to setattr() during zone boot.
 	 */
-	(void) strlcpy(data->lxzd_kernel_version, "2.4.21", LX_VERS_MAX);
+	(void) strlcpy(data->lxzd_kernel_release, "2.4.21",
+	    LX_KERN_RELEASE_MAX);
+	(void) strlcpy(data->lxzd_kernel_version, "BrandZ virtual linux",
+	    LX_KERN_VERSION_MAX);
 
 	/*
 	 * Linux is not at all picky about address family when it comes to
@@ -1369,32 +1413,43 @@ lx_brandsys(int cmd, int64_t *rval, uintptr_t arg1, uintptr_t arg2,
 		exit(code, sig);
 		/* NOTREACHED */
 		break;
-	}
 
-	return (EINVAL);
-}
+	case B_OVERRIDE_KERN_VER: {
+		void *urel = (void *)arg1;
+		void *uver = (void *)arg2;
+		size_t len;
 
-char *
-lx_get_zone_kern_version(zone_t *zone)
-{
-	return (((lx_zone_data_t *)zone->zone_brand_data)->lxzd_kernel_version);
-}
+		pd = ptolxproc(p);
+		if (urel != NULL) {
+			if (copyinstr(urel, pd->l_uname_release,
+			    LX_KERN_RELEASE_MAX, &len) != 0) {
+				return (EFAULT);
+			}
+			pd->l_uname_release[LX_KERN_RELEASE_MAX - 1] = '\0';
+		}
+		if (uver != NULL) {
+			if (copyinstr(uver, pd->l_uname_version,
+			    LX_KERN_VERSION_MAX, &len) != 0) {
+				return (EFAULT);
+			}
+			pd->l_uname_version[LX_KERN_VERSION_MAX - 1] = '\0';
+		}
 
-void
-lx_set_kern_version(zone_t *zone, char *vers)
-{
-	lx_zone_data_t *lxzd = (lx_zone_data_t *)zone->zone_brand_data;
+		return (0);
+	}
 
-	(void) strlcpy(lxzd->lxzd_kernel_version, vers, LX_VERS_MAX);
+	}
+
+	return (EINVAL);
 }
 
 /*
  * Compare linux kernel version to the one set for the zone.
  * Returns greater than 0 if zone version is higher, less than 0 if the zone
- * version is lower, and 0 if the version are equal.
+ * version is lower, and 0 if the versions are equal.
  */
 int
-lx_kern_version_cmp(zone_t *zone, const char *vers)
+lx_kern_release_cmp(zone_t *zone, const char *vers)
 {
 	int zvers[3] = {0, 0, 0};
 	int cvers[3] = {0, 0, 0};
@@ -1402,7 +1457,7 @@ lx_kern_version_cmp(zone_t *zone, const char *vers)
 
 	VERIFY(zone->zone_brand == &lx_brand);
 
-	(void) sscanf(ztolxzd(zone)->lxzd_kernel_version, "%d.%d.%d", &zvers[0],
+	(void) sscanf(ztolxzd(zone)->lxzd_kernel_release, "%d.%d.%d", &zvers[0],
 	    &zvers[1], &zvers[2]);
 	(void) sscanf(vers, "%d.%d.%d", &cvers[0], &cvers[1], &cvers[2]);
 
@@ -1444,17 +1499,25 @@ lx_setid_clear(vattr_t *vap, cred_t *cr)
  * Copy the per-process brand data from a parent proc to a child.
  */
 void
-lx_copy_procdata(proc_t *child, proc_t *parent)
+lx_copy_procdata(proc_t *cp, proc_t *pp)
 {
-	lx_proc_data_t *cpd = child->p_brand_data;
-	lx_proc_data_t *ppd = parent->p_brand_data;
+	lx_proc_data_t *cpd, *ppd;
+	char buf_version[LX_SYS_UTS_LN];
+
+	/*
+	 * Since b_copy_procdata is called during getproc(), while the child
+	 * process is still being initialized, acquiring cp->p_lock should not
+	 * be required.
+	 */
+	VERIFY(cp->p_brand == &lx_brand);
+	VERIFY(cpd = cp->p_brand_data);
 
-	VERIFY(parent->p_brand == &lx_brand);
-	VERIFY(child->p_brand == &lx_brand);
-	VERIFY(ppd != NULL);
-	VERIFY(cpd != NULL);
+	mutex_enter(&pp->p_lock);
+	VERIFY(pp->p_brand == &lx_brand);
+	VERIFY(ppd = pp->p_brand_data);
 
-	*cpd = *ppd;
+	bcopy(ppd, cpd, sizeof (lx_proc_data_t));
+	mutex_exit(&pp->p_lock);
 
 	cpd->l_fake_limits[LX_RLFAKE_LOCKS].rlim_cur = LX_RLIM64_INFINITY;
 	cpd->l_fake_limits[LX_RLFAKE_LOCKS].rlim_max = LX_RLIM64_INFINITY;
diff --git a/usr/src/uts/common/brand/lx/os/lx_syscall.c b/usr/src/uts/common/brand/lx/os/lx_syscall.c
index 0598a7d997..ad52900dba 100644
--- a/usr/src/uts/common/brand/lx/os/lx_syscall.c
+++ b/usr/src/uts/common/brand/lx/os/lx_syscall.c
@@ -645,7 +645,7 @@ lx_sysent_t lx_sysent32[] = {
 	{"sigreturn",	NULL,			0,		1}, /* 119 */
 	{"clone",	NULL,			0,		5}, /* 120 */
 	{"setdomainname", NULL,			0,		2}, /* 121 */
-	{"uname",	NULL,			0,		1}, /* 122 */
+	{"uname",	lx_uname,		0,		1}, /* 122 */
 	{"modify_ldt",	lx_modify_ldt,		0,		3}, /* 123 */
 	{"adjtimex",	NULL,			0,		1}, /* 124 */
 	{"mprotect",	NULL,			0,		3}, /* 125 */
@@ -957,7 +957,7 @@ lx_sysent_t lx_sysent64[] = {
 	{"exit",	NULL,			0,		1}, /* 60 */
 	{"wait4",	lx_wait4,		0,		4}, /* 61 */
 	{"kill",	lx_kill,		0,		2}, /* 62 */
-	{"uname",	NULL,			0,		1}, /* 63 */
+	{"uname",	lx_uname,		0,		1}, /* 63 */
 	{"semget",	NULL,			0,		3}, /* 64 */
 	{"semop",	NULL,			0,		3}, /* 65 */
 	{"semctl",	NULL,			0,		4}, /* 66 */
diff --git a/usr/src/uts/common/brand/lx/procfs/lx_prvnops.c b/usr/src/uts/common/brand/lx/procfs/lx_prvnops.c
index 1cc74357ce..cde72b42bb 100644
--- a/usr/src/uts/common/brand/lx/procfs/lx_prvnops.c
+++ b/usr/src/uts/common/brand/lx/procfs/lx_prvnops.c
@@ -3408,14 +3408,12 @@ lxpr_read_diskstats(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 static void
 lxpr_read_version(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 {
-	char *vers;
-
-	vers = lx_get_zone_kern_version(LXPTOZ(lxpnp));
+	lx_zone_data_t *lxzd = ztolxzd(LXPTOZ(lxpnp));
 
 	lxpr_uiobuf_printf(uiobuf,
 	    "%s version %s (%s version %d.%d.%d) "
 	    "#%s SMP %s\n",
-	    LX_UNAME_SYSNAME, vers,
+	    LX_UNAME_SYSNAME, lxzd->lxzd_kernel_release,
 #if defined(__GNUC__)
 	    "gcc",
 	    __GNUC__,
@@ -3427,7 +3425,7 @@ lxpr_read_version(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 	    (__SUNPRO_C & 0xff) / 0x10,
 	    __SUNPRO_C & 0xf,
 #endif
-	    LX_UNAME_VERSION,
+	    lxzd->lxzd_kernel_version,
 	    "00:00:00 00/00/00");
 }
 
@@ -3456,7 +3454,8 @@ lxpr_read_stat(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 	ulong_t pswitch_cum = 0;
 	ulong_t forks_cum = 0;
 	hrtime_t msnsecs[NCMSTATES];
-	char *lx_kern_version = lx_get_zone_kern_version(LXPTOZ(lxpnp));
+	/* is the emulated release > 2.4 */
+	boolean_t newer_than24 = lx_kern_release_cmp(LXPTOZ(lxpnp), "2.4") > 0;
 	/* temporary variable since scalehrtime modifies data in place */
 	hrtime_t tmptime;
 
@@ -3489,7 +3488,8 @@ lxpr_read_stat(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 		pgswapin_cum += CPU_STATS(cp, vm.pgswapin);
 		pgswapout_cum += CPU_STATS(cp, vm.pgswapout);
 
-		if (strncmp(lx_kern_version, "2.4", 3) != 0) {
+
+		if (newer_than24) {
 			cpu_nrunnable_cum += cp->cpu_disp->disp_nrunnable;
 			w_io_cum += CPU_STATS(cp, sys.iowait);
 			for (i = 0; i < NCMSTATES; i++) {
@@ -3512,7 +3512,7 @@ lxpr_read_stat(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 			cp = cp->cpu_next;
 	} while (cp != cpstart);
 
-	if (strncmp(lx_kern_version, "2.4", 3) != 0) {
+	if (newer_than24) {
 		lxpr_uiobuf_printf(uiobuf,
 		    "cpu %lu %lu %lu %lu %lu %lu %lu\n",
 		    user_cum, 0L, sys_cum, idle_cum, 0L, irq_cum, 0L);
@@ -3551,7 +3551,7 @@ lxpr_read_stat(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 			irq_ticks += NSEC_TO_TICK(tmptime);
 		}
 
-		if (strncmp(lx_kern_version, "2.4", 3) != 0) {
+		if (newer_than24) {
 			lxpr_uiobuf_printf(uiobuf,
 			    "cpu%d %lu %lu %lu %lu %lu %lu %lu\n",
 			    cp->cpu_id, user_ticks, 0L, sys_ticks, idle_ticks,
@@ -3571,7 +3571,7 @@ lxpr_read_stat(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
 
 	mutex_exit(&cpu_lock);
 
-	if (strncmp(lx_kern_version, "2.4", 3) != 0) {
+	if (newer_than24) {
 		lxpr_uiobuf_printf(uiobuf,
 		    "page %lu %lu\n"
 		    "swap %lu %lu\n"
diff --git a/usr/src/uts/common/brand/lx/sys/lx_brand.h b/usr/src/uts/common/brand/lx/sys/lx_brand.h
index 895ea44db5..7198bea59c 100644
--- a/usr/src/uts/common/brand/lx/sys/lx_brand.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_brand.h
@@ -97,6 +97,7 @@ extern "C" {
 #define	B_HELPER_TGSIGQUEUE	146
 #define	B_SET_NATIVE_STACK	147
 #define	B_SIGEV_THREAD_ID	148
+#define	B_OVERRIDE_KERN_VER	149
 
 #ifndef _ASM
 /*
@@ -143,7 +144,8 @@ typedef enum lx_ptrace_options {
 #define	LX_VERSION_1		1
 #define	LX_VERSION		LX_VERSION_1
 
-#define	LX_KERN_VERSION_NUM	ZONE_ATTR_BRAND_ATTRS
+#define	LX_ATTR_KERN_RELEASE	ZONE_ATTR_BRAND_ATTRS
+#define	LX_ATTR_KERN_VERSION	(ZONE_ATTR_BRAND_ATTRS + 1)
 
 /*
  * Aux vector containing phdr of Linux executable and ehdr of interpreter
@@ -382,6 +384,13 @@ typedef enum lx_proc_flags {
 
 #define	LX_PROC_ALL	(LX_PROC_INSTALL_MODE | LX_PROC_STRICT_MODE)
 
+/* Maximum length for fields of LX uname */
+#define	LX_SYS_UTS_LN	65
+
+/* Max. length of kernel release string */
+#define	LX_KERN_RELEASE_MAX	LX_SYS_UTS_LN
+#define	LX_KERN_VERSION_MAX	LX_SYS_UTS_LN
+
 #ifdef	_KERNEL
 
 /*
@@ -418,6 +427,10 @@ typedef struct lx_proc_data {
 	lx_proc_flags_t l_flags;
 
 	lx_rlimit64_t l_fake_limits[LX_RLFAKE_NLIMITS];
+
+	/* Override zone-wide settings for uname release and version */
+	char l_uname_release[LX_KERN_RELEASE_MAX];
+	char l_uname_version[LX_KERN_VERSION_MAX];
 } lx_proc_data_t;
 
 #endif	/* _KERNEL */
@@ -431,9 +444,6 @@ typedef struct lx_proc_data {
 #define	LX_AFF_ULONGS	(LX_NCPU / (8 * sizeof (ulong_t)))
 typedef ulong_t lx_affmask_t[LX_AFF_ULONGS];
 
-/* Max. length of kernel version string */
-#define	LX_VERS_MAX	16
-
 /* Length of proc boot_id string */
 #define	LX_BOOTID_LEN	37
 
@@ -649,7 +659,8 @@ struct lx_lwp_data {
  * enhanced to support different mounts with different subsystem controllers.
  */
 typedef struct lx_zone_data {
-	char lxzd_kernel_version[LX_VERS_MAX];
+	char lxzd_kernel_release[LX_KERN_RELEASE_MAX];
+	char lxzd_kernel_version[LX_KERN_VERSION_MAX];
 	ksocket_t lxzd_ioctl_sock;
 	char lxzd_bootid[LX_BOOTID_LEN];	/* procfs boot_id */
 	vfs_t *lxzd_cgroup;			/* cgroup for this zone */
@@ -684,8 +695,7 @@ typedef struct lx_zone_data {
 #define	LX_MAX_SYSCALL(lwp)	lx_nsysent32
 #endif
 
-extern char *lx_get_zone_kern_version(zone_t *);
-extern int lx_kern_version_cmp(zone_t *, const char *);
+extern int lx_kern_release_cmp(zone_t *, const char *);
 
 extern void lx_lwp_set_native_stack_current(lx_lwp_data_t *, uintptr_t);
 extern void lx_divert(klwp_t *, uintptr_t);
diff --git a/usr/src/uts/common/brand/lx/sys/lx_syscalls.h b/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
index c4a2307592..3202bb5455 100644
--- a/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
@@ -108,6 +108,7 @@ extern long lx_sysinfo64();
 extern long lx_tgkill();
 extern long lx_time();
 extern long lx_tkill();
+extern long lx_uname();
 extern long lx_wait4();
 extern long lx_waitid();
 extern long lx_waitpid();
diff --git a/usr/src/uts/common/brand/lx/sys/lx_types.h b/usr/src/uts/common/brand/lx/sys/lx_types.h
index e91484c16b..9293d00ae1 100644
--- a/usr/src/uts/common/brand/lx/sys/lx_types.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_types.h
@@ -54,16 +54,6 @@ extern "C" {
 
 #endif /* !_KERNEL */
 
-#define	LX_SYS_UTS_LN	65
-
-struct lx_utsname {
-	char	sysname[LX_SYS_UTS_LN];
-	char	nodename[LX_SYS_UTS_LN];
-	char	release[LX_SYS_UTS_LN];
-	char	version[LX_SYS_UTS_LN];
-	char	machine[LX_SYS_UTS_LN];
-	char	domainname[LX_SYS_UTS_LN];
-};
 
 typedef	uint64_t	lx_dev_t;
 typedef	uint16_t	lx_dev16_t;
diff --git a/usr/src/uts/common/brand/lx/syscall/lx_uname.c b/usr/src/uts/common/brand/lx/syscall/lx_uname.c
new file mode 100644
index 0000000000..1b9f6b31c1
--- /dev/null
+++ b/usr/src/uts/common/brand/lx/syscall/lx_uname.c
@@ -0,0 +1,76 @@
+/*
+ * 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 2015 Joyent, Inc.
+ */
+
+#include <sys/types.h>
+#include <sys/systm.h>
+#include <sys/thread.h>
+#include <sys/proc.h>
+#include <sys/zone.h>
+#include <sys/brand.h>
+#include <sys/lx_brand.h>
+#include <sys/lx_types.h>
+
+struct lx_utsname {
+	char lxu_sysname[LX_SYS_UTS_LN];
+	char lxu_nodename[LX_SYS_UTS_LN];
+	char lxu_release[LX_SYS_UTS_LN];
+	char lxu_version[LX_SYS_UTS_LN];
+	char lxu_machine[LX_SYS_UTS_LN];
+	char lxu_domainname[LX_SYS_UTS_LN];
+};
+
+long
+lx_uname(void *uptr)
+{
+	proc_t *p = curproc;
+	lx_proc_data_t *lxpd = ptolxproc(p);
+	lx_zone_data_t *lxzd = ztolxzd(p->p_zone);
+	struct lx_utsname un;
+
+	bzero(&un, sizeof (un));
+
+	(void) strlcpy(un.lxu_sysname, LX_UNAME_SYSNAME, LX_SYS_UTS_LN);
+	(void) strlcpy(un.lxu_nodename, p->p_zone->zone_nodename,
+	    LX_SYS_UTS_LN);
+	if (lxpd->l_uname_release[0] != '\0') {
+		(void) strlcpy(un.lxu_release, lxpd->l_uname_release,
+		    LX_SYS_UTS_LN);
+	} else {
+		(void) strlcpy(un.lxu_release, lxzd->lxzd_kernel_release,
+		    LX_SYS_UTS_LN);
+	}
+	if (lxpd->l_uname_version[0] != '\0') {
+		(void) strlcpy(un.lxu_version, lxpd->l_uname_version,
+		    LX_SYS_UTS_LN);
+	} else {
+		(void) strlcpy(un.lxu_version, lxzd->lxzd_kernel_version,
+		    LX_SYS_UTS_LN);
+	}
+	if (get_udatamodel() == DATAMODEL_LP64) {
+		(void) strlcpy(un.lxu_machine, LX_UNAME_MACHINE64,
+		    LX_SYS_UTS_LN);
+	} else {
+		(void) strlcpy(un.lxu_machine, LX_UNAME_MACHINE32,
+		    LX_SYS_UTS_LN);
+	}
+	(void) strlcpy(un.lxu_domainname, p->p_zone->zone_domain,
+	    LX_SYS_UTS_LN);
+
+	if (copyout(&un, uptr, sizeof (un)) != 0) {
+		return (set_errno(EFAULT));
+	}
+
+	return (0);
+}
diff --git a/usr/src/uts/intel/Makefile.files b/usr/src/uts/intel/Makefile.files
index 236e824127..78c9de19f2 100644
--- a/usr/src/uts/intel/Makefile.files
+++ b/usr/src/uts/intel/Makefile.files
@@ -321,6 +321,7 @@ LX_BRAND_OBJS  =		\
 	lx_sysinfo.o		\
 	lx_thread_area.o	\
 	lx_timer.o		\
+	lx_uname.o		\
 	lx_wait.o		\
 	lx_xattr.o