[Qemu-devel] [PATCH] linux-user: use libc wrapper instead of direct mremap syscall

[Felix Janda <felix.janda@posteo.de>]

This commit essentially reverts commit
3af72a4d98dca033492102603734cbc63cd2694a, which has replaced
five-argument calls to mremap() by direct mremap syscalls for
compatibility with glibc older than version 2.4.

The direct syscall was buggy for 64bit targets on 32bit hosts
because of the default integer type promotions. Since glibc-2.4
is now a decade old, we can remove this workaround.

Signed-off-by: Felix Janda <felix.janda@posteo.de>
---
 linux-user/mmap.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index c4371d9..ffd099d 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -17,8 +17,6 @@
  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "qemu/osdep.h"
-#include <linux/mman.h>
-#include <linux/unistd.h>
 
 #include "qemu.h"
 #include "qemu-common.h"
@@ -681,10 +679,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
     mmap_lock();
 
     if (flags & MREMAP_FIXED) {
-        host_addr = (void *) syscall(__NR_mremap, g2h(old_addr),
-                                     old_size, new_size,
-                                     flags,
-                                     g2h(new_addr));
+        host_addr = mremap(g2h(old_addr), old_size, new_size,
+                           flags, g2h(new_addr));
 
         if (reserved_va && host_addr != MAP_FAILED) {
             /* If new and old addresses overlap then the above mremap will
@@ -700,10 +696,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
             errno = ENOMEM;
             host_addr = MAP_FAILED;
         } else {
-            host_addr = (void *) syscall(__NR_mremap, g2h(old_addr),
-                                         old_size, new_size,
-                                         flags | MREMAP_FIXED,
-                                         g2h(mmap_start));
+            host_addr = mremap(g2h(old_addr), old_size, new_size,
+                               flags | MREMAP_FIXED, g2h(mmap_start));
             if (reserved_va) {
                 mmap_reserve(old_addr, old_size);
             }
-- 
2.7.3