[Xen-changelog] [xen master] x86/MCFG: fix off-by-one in E820 check

[patchbot@xxxxxxx]

commit a5dccdd86651f6d7eb0c2b9fb0347a4e770184ff
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Feb 18 16:24:24 2020 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Feb 18 16:24:24 2020 +0100

    x86/MCFG: fix off-by-one in E820 check
    
    Also adjust the comment ahead of e820_all_mapped() to clarify that the
    range is not inclusive at its end.
    
    Reported-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Wei Liu <wl@xxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/e820.c                   | 5 +++--
 xen/arch/x86/x86_64/mmconfig-shared.c | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/e820.c b/xen/arch/x86/e820.c
index c9dc52c768..aa602773bb 100644
--- a/xen/arch/x86/e820.c
+++ b/xen/arch/x86/e820.c
@@ -38,7 +38,7 @@ struct e820map e820;
 struct e820map __initdata e820_raw;
 
 /*
- * This function checks if the entire range <start,end> is mapped with type.
+ * This function checks if the entire range [start,end) is mapped with type.
  *
  * Note: this function only works correct if the e820 table is sorted and
  * not-overlapping, which is the case
@@ -56,7 +56,8 @@ int __init e820_all_mapped(u64 start, u64 end, unsigned type)
                if (ei->addr >= end || ei->addr + ei->size <= start)
                        continue;
 
-               /* if the region is at the beginning of <start,end> we move
+               /*
+                * If the region is at the beginning of [start,end) we move
                 * start to the end of the region since it's ok until there
                 */
                if (ei->addr <= start)
diff --git a/xen/arch/x86/x86_64/mmconfig-shared.c 
b/xen/arch/x86/x86_64/mmconfig-shared.c
index 0c55c7206e..7c3ed64b4c 100644
--- a/xen/arch/x86/x86_64/mmconfig-shared.c
+++ b/xen/arch/x86/x86_64/mmconfig-shared.c
@@ -337,7 +337,7 @@ static int __init is_mmconf_reserved(
     u64 old_size = size;
     int valid = 0;
 
-    while (!e820_all_mapped(addr, addr + size - 1, E820_RESERVED)) {
+    while (!e820_all_mapped(addr, addr + size, E820_RESERVED)) {
         size >>= 1;
         if (size < (16UL<<20))
             break;
--
generated by git-patchbot for /home/xen/git/xen.git#master

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