Use the newly provided aux vectors to get pagesize and osreldate information.

Use local version of getpagesize(), rtld_getpagesize() in private allocator.
Override the __getosreldate() previously fetched from libc_pic.a with
local version that uses aux value if present. Note that __getosreldate()
is used by rtld indirectly, by mmap(2) libc wrapper.

To be able to utilize aux, split digest_dynamic() for use by init_rtld()
into two parts, where the first one does not call malloc(), and the
second part uses it. init_rtld() is able to initialize global variables
before digest_dynamic2() calls. In particular, pagesize and osreldate are
set up from the aux values.

Now, rtld avoids (two) sysctl calls in startup.

Tested by:	marius (sparc64)
MFC after:	1 month

1 files changed, 22 insertions, 1 deletions

diff --git a/libexec/rtld-elf/malloc.c b/libexec/rtld-elf/malloc.c
index 3da5bee..38ae89a 100644
--- a/libexec/rtld-elf/malloc.c
+++ b/libexec/rtld-elf/malloc.c
@@ -48,6 +48,7 @@ static char *rcsid = "$FreeBSD$";
  */
 
 #include <sys/types.h>
+#include <sys/sysctl.h>
 #include <err.h>
 #include <paths.h>
 #include <stdarg.h>
@@ -152,6 +153,26 @@ botch(s)
 static void xprintf(const char *, ...);
 #define TRACE()	xprintf("TRACE %s:%d\n", __FILE__, __LINE__)
 
+extern int pagesize;
+
+static int
+rtld_getpagesize(void)
+{
+	int mib[2];
+	size_t size;
+
+	if (pagesize != 0)
+		return (pagesize);
+
+	mib[0] = CTL_HW;
+	mib[1] = HW_PAGESIZE;
+	size = sizeof(pagesize);
+	if (sysctl(mib, 2, &pagesize, &size, NULL, 0) == -1)
+		return (-1);
+	return (pagesize);
+
+}
+
 void *
 malloc(nbytes)
 	size_t nbytes;
@@ -166,7 +187,7 @@ malloc(nbytes)
 	 * align break pointer so all data will be page aligned.
 	 */
 	if (pagesz == 0) {
-		pagesz = n = getpagesize();
+		pagesz = n = rtld_getpagesize();
 		if (morepages(NPOOLPAGES) == 0)
 			return NULL;
 		op = (union overhead *)(pagepool_start);