Add descriptive names to sanitizer entries in /proc/self/maps. Helps debugging.

This is done by creating a named shared memory region, unlinking it
and setting up a private (i.e. copy-on-write) mapping of that instead
of a regular anonymous mapping. I've experimented with regular
(sparse) files, but they can not be scaled to the size of MSan shadow
mapping, at least on Linux/X86_64 and ext3 fs.

Controlled by a common flag, decorate_proc_maps, disabled by default.

This patch has a few shortcomings:
* not all mappings are annotated, especially in TSan.
* our handling of memset() of shadow via mmap() puts small anonymous
  mappings inside larger named mappings, which looks ugly and can, in
  theory, hit the mapping number limit.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@238621 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 23 deletions

diff --git a/lib/sanitizer_common/sanitizer_posix.cc b/lib/sanitizer_common/sanitizer_posix.cc
index 0b6d35eb1..de4b8d140 100644
--- a/lib/sanitizer_common/sanitizer_posix.cc
+++ b/lib/sanitizer_common/sanitizer_posix.cc
@@ -165,22 +165,6 @@ void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
   return (void *)p;
 }
 
-void *MmapFixedNoReserve(uptr fixed_addr, uptr size) {
-  uptr PageSize = GetPageSizeCached();
-  uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
-      RoundUpTo(size, PageSize),
-      PROT_READ | PROT_WRITE,
-      MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE,
-      -1, 0);
-  int reserrno;
-  if (internal_iserror(p, &reserrno))
-    Report("ERROR: %s failed to "
-           "allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n",
-           SanitizerToolName, size, size, fixed_addr, reserrno);
-  IncreaseTotalMmap(size);
-  return (void *)p;
-}
-
 void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
   uptr PageSize = GetPageSizeCached();
   uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
@@ -199,13 +183,6 @@ void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
   return (void *)p;
 }
 
-void *MmapNoAccess(uptr fixed_addr, uptr size) {
-  return (void *)internal_mmap((void*)fixed_addr, size,
-                               PROT_NONE,
-                               MAP_PRIVATE | MAP_ANON | MAP_FIXED |
-                               MAP_NORESERVE, -1, 0);
-}
-
 bool MprotectNoAccess(uptr addr, uptr size) {
   return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
 }