[xen staging] x86/NUMA: correct off-by-1 in node map population

[patchbot@xxxxxxx]

commit 66a5633aa038f4abb4455463755974febac69034
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Oct 5 10:55:27 2022 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Oct 5 10:55:27 2022 +0200

    x86/NUMA: correct off-by-1 in node map population
    
    As it turns out populate_memnodemap() so far "relied" on
    extract_lsb_from_nodes() setting memnodemapsize one too high in edge
    cases. Correct the issue there as well, by changing "epdx" to be an
    inclusive PDX and adjusting the respective relational operators.
    
    While there also limit the scope of both related variables.
    
    Fixes: b1f4b45d02ca ("x86/NUMA: correct off-by-1 in node map size 
calculation")
    Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Release-acked-by: Henry Wang <Henry.Wang@xxxxxxx>
---
 xen/arch/x86/numa.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/numa.c b/xen/arch/x86/numa.c
index 2c3c1c15fe..322157fab7 100644
--- a/xen/arch/x86/numa.c
+++ b/xen/arch/x86/numa.c
@@ -65,15 +65,15 @@ int srat_disabled(void)
 static int __init populate_memnodemap(const struct node *nodes,
                                       int numnodes, int shift, nodeid_t 
*nodeids)
 {
-    unsigned long spdx, epdx;
     int i, res = -1;
 
     memset(memnodemap, NUMA_NO_NODE, memnodemapsize * sizeof(*memnodemap));
     for ( i = 0; i < numnodes; i++ )
     {
-        spdx = paddr_to_pdx(nodes[i].start);
-        epdx = paddr_to_pdx(nodes[i].end - 1) + 1;
-        if ( spdx >= epdx )
+        unsigned long spdx = paddr_to_pdx(nodes[i].start);
+        unsigned long epdx = paddr_to_pdx(nodes[i].end - 1);
+
+        if ( spdx > epdx )
             continue;
         if ( (epdx >> shift) >= memnodemapsize )
             return 0;
@@ -88,7 +88,7 @@ static int __init populate_memnodemap(const struct node 
*nodes,
                 memnodemap[spdx >> shift] = nodeids[i];
 
             spdx += (1UL << shift);
-        } while ( spdx < epdx );
+        } while ( spdx <= epdx );
         res = 1;
     }
 
--
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