From: Alex Bennée <alex.bennee@linaro.org>
Date: Fri, 3 Apr 2020 19:11:42 +0000 (+0100)
Subject: linux-user: more debug for init_guest_space
X-Git-Tag: qemu-xen-4.14.0~25^2~8
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=b859040dc44b271e9ad29f729cac71d2389b05fd;p=qemu-xen.git

linux-user: more debug for init_guest_space

Searching for memory space can cause problems so lets extend the
CPU_LOG_PAGE output so you can watch init_guest_space fail to
allocate memory. A more involved fix is actually required to make this
function play nicely with the large guard pages the sanitiser likes to
use.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200403191150.863-5-alex.bennee@linaro.org>
---

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 8198be0446..619c054cc4 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2172,6 +2172,8 @@ unsigned long init_guest_space(unsigned long host_start,
 
         /* Check to see if the address is valid.  */
         if (host_start && real_start != current_start) {
+            qemu_log_mask(CPU_LOG_PAGE, "invalid %lx && %lx != %lx\n",
+                          host_start, real_start, current_start);
             goto try_again;
         }
 
@@ -2240,7 +2242,11 @@ unsigned long init_guest_space(unsigned long host_start,
          * probably a bad strategy if not, which means we got here
          * because of trouble with ARM commpage setup.
          */
-        munmap((void *)real_start, real_size);
+        if (munmap((void *)real_start, real_size) != 0) {
+            error_report("%s: failed to unmap %lx:%lx (%s)", __func__,
+                         real_start, real_size, strerror(errno));
+            abort();
+        }
         current_start += align;
         if (host_start == current_start) {
             /* Theoretically possible if host doesn't have any suitably