From: Petr Machata <pmachata@redhat.com>
Date: Thu, 12 Nov 2009 23:38:27 +0000 (+0100)
Subject: Load ahead core file chunk only if the area is vaddr-contiguous
X-Git-Tag: elfutils-0.144~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=003dd328425b57a5944dfd1454cb0e73c8f615dd;p=thirdparty%2Felfutils.git

Load ahead core file chunk only if the area is vaddr-contiguous
---

diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index 9e76838fd..c210bcae2 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,3 +1,8 @@
+2009-11-12  Petr Machata  <pmachata@redhat.com>
+
+	* core-file.c (dwfl_elf_phdr_memory_callback): Only load ahead if
+	the chunk is both offset-contiguous and vaddr-contiguous.
+
 2009-11-05  Roland McGrath  <roland@redhat.com>
 
 	* link_map.c (report_r_debug): Skip entries with l_ld==0.
diff --git a/libdwfl/core-file.c b/libdwfl/core-file.c
index 77f208cc7..ad1c78d8f 100644
--- a/libdwfl/core-file.c
+++ b/libdwfl/core-file.c
@@ -283,7 +283,16 @@ dwfl_elf_phdr_memory_callback (Dwfl *dwfl, int ndx,
 	 || ((phdr.p_vaddr + phdr.p_memsz + align - 1) & -align) <= vaddr);
 
   GElf_Off start = vaddr - phdr.p_vaddr + phdr.p_offset;
-  GElf_Off end = (phdr.p_offset + phdr.p_filesz + align - 1) & -align;
+  GElf_Off end;
+  GElf_Addr end_vaddr;
+
+  inline void update_end ()
+  {
+    end = (phdr.p_offset + phdr.p_filesz + align - 1) & -align;
+    end_vaddr = (phdr.p_vaddr + phdr.p_memsz + align - 1) & -align;
+  }
+
+  update_end ();
 
   /* Use following contiguous segments to get towards SIZE.  */
   inline bool more (size_t size)
@@ -299,11 +308,12 @@ dwfl_elf_phdr_memory_callback (Dwfl *dwfl, int ndx,
 
 	if (phdr.p_type == PT_LOAD)
 	  {
-	    if (phdr.p_offset > end)
+	    if (phdr.p_offset > end
+		|| phdr.p_vaddr > end_vaddr)
 	      /* It's discontiguous!  */
 	      return false;
 
-	    end = (phdr.p_offset + phdr.p_filesz + align - 1) & -align;
+	    update_end ();
 	  }
       }
     return true;