[sanitizer] Adjust max read size in FlagHandlerInclude

Setting the maximum read size in FlagHandlerInclude to 2^15 might be a good
default, but causes the read to fail on systems with a page size larger than
that (ReadFileToBuffer(...) will fail if the maximum allowed size is less than
the value returned by GetPageSizeCached()). For example, on my PPC64/Linux
system, GetPageSizeCached() returns 2^16. In case the page size is larger, use
that instead.

llvm-svn: 226368

1 files changed, 2 insertions, 1 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc b/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc
index bc85a2a634d..8be50c39af5 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc
@@ -56,7 +56,8 @@ class FlagHandlerInclude : public FlagHandlerBase {
     uptr data_mapped_size;
     int err;
     uptr len =
-      ReadFileToBuffer(value, &data, &data_mapped_size, kMaxIncludeSize, &err);
+      ReadFileToBuffer(value, &data, &data_mapped_size,
+                       Max(kMaxIncludeSize, GetPageSizeCached()), &err);
     if (!len) {
       Printf("Failed to read options from '%s': error %d\n", value, err);
       return false;