Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-3.0-pull-request' into staging

Some fixes for linux-user:
- workaround for CMSG_NXTHDR bug
- two patches for ppc64/ppc64le host:
  fix fcntl() with *LK64 commands
  (seen when dpkg wants to lock the DB)
  fix reserved_va alignment (ppc64 needs
  a 64kB alignment)
- convert a forgotten fcntl() to safe_fcntl()

# gpg: Signature made Sun 15 Jul 2018 20:51:19 BST
# gpg:                using RSA key F30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>"
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>"
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>"
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/linux-user-for-3.0-pull-request:
  Zero out the host's `msg_control` buffer
  linux-user: fix mmap_find_vma_reserved()
  linux-user: convert remaining fcntl() to safe_fcntl()
  linux-user: ppc64: use the correct values for F_*LK64s

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

1 files changed, 12 insertions, 7 deletions

diff --git a/linux-user/main.c b/linux-user/main.c
index 52b5a618fe..ea00dd9057 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -78,14 +78,7 @@ int have_guest_base;
 # endif
 #endif
 
-/* That said, reserving *too* much vm space via mmap can run into problems
-   with rlimits, oom due to page table creation, etc.  We will still try it,
-   if directed by the command-line option, but not by default.  */
-#if HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32
-unsigned long reserved_va = MAX_RESERVED_VA;
-#else
 unsigned long reserved_va;
-#endif
 
 static void usage(int exitcode);
 
@@ -672,6 +665,18 @@ int main(int argc, char **argv, char **envp)
     /* init tcg before creating CPUs and to get qemu_host_page_size */
     tcg_exec_init(0);
 
+    /* Reserving *too* much vm space via mmap can run into problems
+       with rlimits, oom due to page table creation, etc.  We will still try it,
+       if directed by the command-line option, but not by default.  */
+    if (HOST_LONG_BITS == 64 &&
+        TARGET_VIRT_ADDR_SPACE_BITS <= 32 &&
+        reserved_va == 0) {
+        /* reserved_va must be aligned with the host page size
+         * as it is used with mmap()
+         */
+        reserved_va = MAX_RESERVED_VA & qemu_host_page_mask;
+    }
+
     cpu = cpu_create(cpu_type);
     env = cpu->env_ptr;
     cpu_reset(cpu);