Fix bionic linker to support segments with zero p_filesz

(cherry picked from commit 96362fb9d11beef6233aa03db396f25688e70860)

Change-Id: Ib075a6dfc45d5d0746d8b278f317dd9b8d772f2a

1 files changed, 13 insertions, 10 deletions

diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index 64dbb70be..d1387f647 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -320,16 +320,19 @@ bool ElfReader::LoadSegments() {
     Elf32_Addr file_end   = file_start + phdr->p_filesz;
 
     Elf32_Addr file_page_start = PAGE_START(file_start);
-
-    void* seg_addr = mmap((void*)seg_page_start,
-                          file_end - file_page_start,
-                          PFLAGS_TO_PROT(phdr->p_flags),
-                          MAP_FIXED|MAP_PRIVATE,
-                          fd_,
-                          file_page_start);
-    if (seg_addr == MAP_FAILED) {
-      DL_ERR("couldn't map \"%s\" segment %d: %s", name_, i, strerror(errno));
-      return false;
+    Elf32_Addr file_length = file_end - file_page_start;
+
+    if (file_length != 0) {
+      void* seg_addr = mmap((void*)seg_page_start,
+                            file_length,
+                            PFLAGS_TO_PROT(phdr->p_flags),
+                            MAP_FIXED|MAP_PRIVATE,
+                            fd_,
+                            file_page_start);
+      if (seg_addr == MAP_FAILED) {
+        DL_ERR("couldn't map \"%s\" segment %d: %s", name_, i, strerror(errno));
+        return false;
+      }
     }
 
     // if the segment is writable, and does not end on a page boundary,