[Xen-devel] [PATCH v4 01/11] livepatch: Expand check for safe_for_reapply if livepatch has only .rodata.

[Konrad Rzeszutek Wilk <konrad@xxxxxxxxxx>]

If the livepatch has only .rodata sections then it is OK to also
apply/revert/apply the livepatch without having to worry about the
unforseen consequences.

See commit 98b728a7b235c67e210f67f789db5d9eb38ca00c
"livepatch: Disallow applying after an revert" for details.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
Cc: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

v3: First posting.
---
 xen/common/livepatch.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index 66167a5573..b0dcd415ba 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -417,9 +417,12 @@ static int move_payload(struct payload *payload, struct 
livepatch_elf *elf)
         }
     }
 
-    /* Only one RW section with non-zero size: .livepatch.funcs */
-    if ( rw_buf_cnt == 1 &&
-         !strcmp(elf->sec[rw_buf_sec].name, ELF_LIVEPATCH_FUNC) )
+    /*
+     * Only one RW section with non-zero size: .livepatch.funcs,
+     * or only RO sections.
+     */
+    if ( !rw_buf_cnt || (rw_buf_cnt == 1 &&
+         !strcmp(elf->sec[rw_buf_sec].name, ELF_LIVEPATCH_FUNC)) )
         payload->safe_to_reapply = true;
  out:
     xfree(offset);
-- 
2.13.3


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