Merge remote-tracking branch 'remotes/mjt/tags/trivial-patches-fetch' into staging

trivial patches for 2017-01-24

# gpg: Signature made Tue 24 Jan 2017 20:27:08 GMT
# gpg:                using RSA key 0x701B4F6B1A693E59
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>"
# gpg:                 aka "Michael Tokarev <mjt@corpit.ru>"
# gpg:                 aka "Michael Tokarev <mjt@debian.org>"
# Primary key fingerprint: 6EE1 95D1 886E 8FFB 810D  4324 457C E0A0 8044 65C5
#      Subkey fingerprint: 7B73 BAD6 8BE7 A2C2 8931  4B22 701B 4F6B 1A69 3E59

* remotes/mjt/tags/trivial-patches-fetch: (31 commits)
  hw/isa/isa-bus: Set category of the "isabus-bridge" device
  usb: Set category and description of the MTP device
  gdbstub.c: update old error report statements
  gdbstub.c: fix GDB connection segfault caused by empty machines
  scsi-disk: add 'fall through' comment to switch VERIFY cases
  Drop duplicate display option documentation
  hw/display/framebuffer.c: Avoid overflow for framebuffers > 4GB
  win32: use glib gpoll if glib >= 2.50
  util/mmap-alloc: refactor a little bit for readability
  util/mmap-alloc: check parameter before using
  vfio: remove a duplicated word in comments
  docs: sync pci-ids.txt
  disas/cris.c: Fix Coverity warning about unchecked NULL
  lm32: milkymist-tmu2: fix another integer overflow
  hw/i386/kvmvapic: Remove dead code in patch_hypercalls()
  doc/usb2: fix typo
  qga: fix erroneous argument to strerror
  block: remove dead check
  pci-assign: avoid pointless stat
  qemu-img: remove dead check
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 8 insertions, 9 deletions

diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 5a85aa3c89..2f55f5e94f 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -12,6 +12,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/mmap-alloc.h"
+#include "qemu/host-utils.h"
 
 #define HUGETLBFS_MAGIC       0x958458f6
 
@@ -61,18 +62,18 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
 #else
     void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 #endif
-    size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
+    size_t offset;
     void *ptr1;
 
     if (ptr == MAP_FAILED) {
         return MAP_FAILED;
     }
 
-    /* Make sure align is a power of 2 */
-    assert(!(align & (align - 1)));
+    assert(is_power_of_2(align));
     /* Always align to host page size */
     assert(align >= getpagesize());
 
+    offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
     ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE,
                 MAP_FIXED |
                 (fd == -1 ? MAP_ANONYMOUS : 0) |
@@ -83,22 +84,20 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
         return MAP_FAILED;
     }
 
-    ptr += offset;
-    total -= offset;
-
     if (offset > 0) {
-        munmap(ptr - offset, offset);
+        munmap(ptr, offset);
     }
 
     /*
      * Leave a single PROT_NONE page allocated after the RAM block, to serve as
      * a guard page guarding against potential buffer overflows.
      */
+    total -= offset;
     if (total > size + getpagesize()) {
-        munmap(ptr + size + getpagesize(), total - size - getpagesize());
+        munmap(ptr1 + size + getpagesize(), total - size - getpagesize());
     }
 
-    return ptr;
+    return ptr1;
 }
 
 void qemu_ram_munmap(void *ptr, size_t size)