From: norly <ny-git@enpas.org>
Date: Sat, 22 Jun 2013 00:02:29 +0000 (+0100)
Subject: Minor fixes to PHDR expansion to lower addresses
X-Git-Url: https://git.enpas.org/?p=centaur.git;a=commitdiff_plain;h=e28b7c5e31e8ab929c2392c079aa2c0bda49b7ac

Minor fixes to PHDR expansion to lower addresses
---

diff --git a/src/libelfu/modelops/layout.c b/src/libelfu/modelops/layout.c
index 65a713d..afa12c9 100644
--- a/src/libelfu/modelops/layout.c
+++ b/src/libelfu/modelops/layout.c
@@ -161,8 +161,10 @@ GElf_Addr elfu_mLayoutGetSpaceInPhdr(ElfuElf *me, GElf_Word size,
       *injPhdr = last;
     }
     return last->phdr.p_vaddr + (injOffset - last->phdr.p_offset);
-  } else if ((w && (first->phdr.p_flags & PF_W))
-             || (x && (first->phdr.p_flags & PF_X))) {
+  } else if (((w && (first->phdr.p_flags & PF_W))
+              || (x && (first->phdr.p_flags & PF_X)))
+             && /* Enough space to expand downwards? */
+             (first->phdr.p_vaddr > 3 * first->phdr.p_align)) {
     /* Need to prepend or split up the PHDR. */
     GElf_Off injOffset = OFFS_END(first->phdr.p_offset, first->phdr.p_filesz);
     ElfuScn *ms;
@@ -194,7 +196,7 @@ GElf_Addr elfu_mLayoutGetSpaceInPhdr(ElfuElf *me, GElf_Word size,
     }
 
     /* Move other PHDRs and sections */
-    assert(size <= shiftStuffAtAfterOffset(me, injOffset, size));
+    assert(size <= shiftStuffAtAfterOffset(me, injOffset + 1, size));
 
     /* Remap ourselves */
     first->phdr.p_vaddr -= size;