From: Razvan Cojocaru <rcojocaru@bitdefender.com>
Date: Thu, 3 Mar 2016 13:58:00 +0000 (+0200)
Subject: libxc: Have xc_translate_foreign_address() set errno properly
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~1544
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=80c4b4c1785aab8053a27931c188c4311189d32d;p=xen.git

libxc: Have xc_translate_foreign_address() set errno properly

Currently it's possible for xc_translate_foreign_address() to fail
and errno still be set to success. This patch fixes the issue.
Based on the first half of Don Slutz' patch:
http://lists.xen.org/archives/html/xen-devel/2014-03/msg03720.html

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
---

diff --git a/tools/libxc/xc_pagetab.c b/tools/libxc/xc_pagetab.c
index ec978904da..92eebd6882 100644
--- a/tools/libxc/xc_pagetab.c
+++ b/tools/libxc/xc_pagetab.c
@@ -88,8 +88,10 @@ unsigned long xc_translate_foreign_address(xc_interface *xch, uint32_t dom,
             return 0;
         memcpy(&pte, map + (paddr & (PAGE_SIZE - 1)), size);
         munmap(map, PAGE_SIZE);
-        if (!(pte & 1)) 
+        if (!(pte & 1)) {
+            errno = EADDRNOTAVAIL;
             return 0;
+        }
         paddr = pte & 0x000ffffffffff000ull;
         if (level == 2 && (pte & PTE_PSE)) {
             mask = ((mask ^ ~-mask) >> 1); /* All bits below first set bit */