As I had suspected, all the go and libgo testsuite failures on 64-bit
Solaris 10 were caused by mmap ignoring the addr argument without
MAP_FIXED. That's the same problem already solved in
gcc/config/host-solaris.c.
The following code is inspired from mmap_fixed() there. If this turns
out to be a license problem again (although iterating over an address
space range page by page is as obvious as it gets), I could recode it
along the lines of gcc/config/alpha/host-osf.c (mmap_fixed), but using
/proc/self/map and the corresponding ioctl instead. This code is mine
(unlike the host-solaris.c one which originated with rth), so I'm free
to relicense as I please. It's unfortunately far longer and harder to
read, but that might be the price to pay ;-(
Bootstrapped on i386-pc-solaris2.11 (where it is unnecessary since mmap
honors addr if possible) and i386-pc-solaris2.10 (where it's required
for the 64-bit tests). There are several
panic: runtime error: invalid memory address or nil pointer dereference
for 64-bit Solaris 10 libgo tests, but all the 64-bit go tests pass
there, so the fundamental problem is gone.
Rainer
2011-04-02 Rainer Orth <[email protected]>
PR go/48240
* configure.ac: Check for mincore.
* configure: Regenerate.
* config.h.in: Regenerate.
* runtime/mem.c: Include unistd.h.
(addrspace_free): New function.
(runtime_SysMap): Retry 64-bit runtime_mmap with MAP_FIXED.
diff --git a/libgo/configure.ac b/libgo/configure.ac
--- a/libgo/configure.ac
+++ b/libgo/configure.ac
@@ -429,7 +429,7 @@ esac
AC_CHECK_HEADERS(sys/mman.h syscall.h sys/epoll.h sys/ptrace.h sys/syscall.h
sys/user.h sys/utsname.h)
AM_CONDITIONAL(HAVE_SYS_MMAN_H, test "$ac_cv_header_sys_mman_h" = yes)
-AC_CHECK_FUNCS(srandom random strerror_r strsignal wait4)
+AC_CHECK_FUNCS(srandom random strerror_r strsignal wait4 mincore)
AM_CONDITIONAL(HAVE_STRERROR_R, test "$ac_cv_func_strerror_r" = yes)
AM_CONDITIONAL(HAVE_WAIT4, test "$ac_cv_func_wait4" = yes)
diff --git a/libgo/runtime/mem.c b/libgo/runtime/mem.c
--- a/libgo/runtime/mem.c
+++ b/libgo/runtime/mem.c
@@ -1,4 +1,5 @@
#include <errno.h>
+#include <unistd.h>
#include "runtime.h"
#include "malloc.h"
@@ -16,6 +17,23 @@
static int dev_zero = -1;
#endif
+static _Bool
+addrspace_free(void *v __attribute__ ((unused)), uintptr n __attribute__
((unused)))
+{
+#ifdef HAVE_MINCORE
+ size_t page_size = getpagesize();
+ size_t off;
+ char one_byte;
+
+ errno = 0;
+ for(off = 0; off < n; off += page_size)
+ if(mincore((char *)v + off, page_size, (char *)&one_byte) != -1
+ || errno != ENOMEM)
+ return 0;
+#endif
+ return 1;
+}
+
void*
runtime_SysAlloc(uintptr n)
{
@@ -109,7 +127,12 @@ runtime_SysMap(void *v, uintptr n)
// On 64-bit, we don't actually have v reserved, so tread carefully.
if(sizeof(void*) == 8) {
p = runtime_mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_ANON|MAP_PRIVATE, fd, 0);
- if(p != v) {
+ if(p != v && addrspace_free(v, n)) {
+ // On some systems, mmap ignores v without
+ // MAP_FIXED, so retry if the address space is free.
+ p = runtime_mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_ANON|MAP_FIXED|MAP_PRIVATE, fd, 0);
+ }
+ if (p != v) {
runtime_printf("runtime: address space conflict:
map(%p) = %p\n", v, p);
runtime_throw("runtime: address space conflict");
}
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
