search

gohome1984 / google-breakpad

Automatically exported from code.google.com/p/google-breakpad
0 stars 0 forks source link

mmap error code checking is not correct #294

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
From r.peniaev:

"Actually, on error ::mmap returns -1, not 0.
E.g. we can easily catch double SIGSEGV on Linux while iterating
modules in /proc/<pid>/maps if some module can't be mapped."

--------- patch -------------

Index: src/common/linux/file_id.cc
===========================================================
========
--- src/common/linux/file_id.cc (revision 309)
+++ src/common/linux/file_id.cc (working copy)
@@ -101,7 +101,7 @@
  }
  void *base = mmap(NULL, st.st_size,
                    PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-  if (!base) {
+  if ( base == MAP_FAILED ) {
    close(fd);
    return false;
  }
Index: src/common/linux/dump_symbols.cc
===========================================================
========
--- src/common/linux/dump_symbols.cc    (revision 309)
+++ src/common/linux/dump_symbols.cc    (working copy)
@@ -759,7 +759,7 @@
    return false;
  void *obj_base = mmap(NULL, st.st_size,
                        PROT_READ | PROT_WRITE, MAP_PRIVATE, obj_fd,
0);
-  if (!obj_base)
+  if ( obj_base == MAP_FAILED )
    return false;
  MmapWrapper map_wrapper(obj_base, st.st_size);
  ElfW(Ehdr) *elf_header = reinterpret_cast<ElfW(Ehdr) *>(obj_base);
Index: src/common/solaris/file_id.cc
===========================================================
========
--- src/common/solaris/file_id.cc       (revision 309)
+++ src/common/solaris/file_id.cc       (working copy)
@@ -151,7 +151,7 @@
    return false;

  void *base = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-  if (!base)
+  if ( base == MAP_FAILED )
    return false;

  bool success = false;
Index: src/common/solaris/dump_symbols.cc
===========================================================
========
--- src/common/solaris/dump_symbols.cc  (revision 309)
+++ src/common/solaris/dump_symbols.cc  (working copy)
@@ -650,7 +650,7 @@
    return false;
  void *obj_base = mmap(NULL, st.st_size,
                        PROT_READ, MAP_PRIVATE, obj_fd, 0);
-  if (!obj_base)
+  if ( obj_base == MAP_FAILED )
    return false;
  MmapWrapper map_wrapper(obj_base, st.st_size);
  GElf_Ehdr elf_header;

Original issue reported on code.google.com by neal...@gmail.com on 22 Feb 2009 at 1:21

GoogleCodeExporter commented 9 years ago

Original comment by neal...@gmail.com on 22 Feb 2009 at 1:34