[Xen-changelog] [xen master] livepatch: Reject payloads with .alternative or .ex_table if support is not built-in.

[patchbot@xxxxxxx]

commit aef04c007490e40d341d1f39c96bd1f7cf4f6376
Author:     Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
AuthorDate: Tue Sep 6 16:28:23 2016 -0400
Commit:     Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CommitDate: Fri Sep 23 12:39:45 2016 -0400

    livepatch: Reject payloads with .alternative or .ex_table if support is not 
built-in.
    
    If the payload had the sections mentioned but the hypervisor
    did not support some of them (say on ARM the .ex_table) - instead
    of ignoring them - it should forbid loading of such payload.
    
    Reviewed-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
    Reviewed-by: Julien Grall <julien.grall@xxxxxxx>
    Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 xen/common/livepatch.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index e14ded6..87a8df2 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -641,10 +641,10 @@ static int prepare_payload(struct payload *payload,
                                   sizeof(*region->frame[i].bugs);
     }
 
-#ifdef CONFIG_HAS_ALTERNATIVE
     sec = livepatch_elf_sec_by_name(elf, ".altinstructions");
     if ( sec )
     {
+#ifdef CONFIG_HAS_ALTERNATIVE
         struct alt_instr *a, *start, *end;
 
         if ( sec->sec->sh_size % sizeof(*a) )
@@ -671,13 +671,17 @@ static int prepare_payload(struct payload *payload,
             }
         }
         apply_alternatives(start, end);
-    }
+#else
+        dprintk(XENLOG_ERR, LIVEPATCH "%s: We don't support alternative 
patching!\n",
+                elf->name);
+        return -EOPNOTSUPP;
 #endif
+    }
 
-#ifdef CONFIG_HAS_EX_TABLE
     sec = livepatch_elf_sec_by_name(elf, ".ex_table");
     if ( sec )
     {
+#ifdef CONFIG_HAS_EX_TABLE
         struct exception_table_entry *s, *e;
 
         if ( !sec->sec->sh_size ||
@@ -696,8 +700,12 @@ static int prepare_payload(struct payload *payload,
 
         region->ex = s;
         region->ex_end = e;
-    }
+#else
+        dprintk(XENLOG_ERR, LIVEPATCH "%s: We don't support .ex_table!\n",
+                elf->name);
+        return -EOPNOTSUPP;
 #endif
+    }
 
     return 0;
 }
--
generated by git-patchbot for /home/xen/git/xen.git#master

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxx
https://lists.xenproject.org/xen-changelog