[scudo][standalone] Add flags & related parsers

Summary:
As with other Sanitizers, and the current version of Scudo, we can
provide flags in differents way: at compile time, through a weak
function, through an environment variable.

This change adds support for the configuration flags, and the string
parsers. Those are fairly similar to the sanitizer_common way of doing
things.

Reviewers: morehouse, hctim, vitalybuka

Reviewed By: morehouse, vitalybuka

Subscribers: mgorny, delcypher, jdoerfert, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D59597

llvm-svn: 358011

1 files changed, 50 insertions, 0 deletions

diff --git a/compiler-rt/lib/scudo/standalone/flags.inc b/compiler-rt/lib/scudo/standalone/flags.inc
new file mode 100644
index 00000000000..25b86e14fa9
--- /dev/null
+++ b/compiler-rt/lib/scudo/standalone/flags.inc
@@ -0,0 +1,50 @@
+//===-- flags.inc -----------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SCUDO_FLAG
+#error "Define SCUDO_FLAG prior to including this file!"
+#endif
+
+SCUDO_FLAG(int, quarantine_size_kb, 0,
+           "Size (in kilobytes) of quarantine used to delay the actual "
+           "deallocation of chunks. Lower value may reduce memory usage but "
+           "decrease the effectiveness of the mitigation.")
+
+SCUDO_FLAG(int, thread_local_quarantine_size_kb, 0,
+           "Size (in kilobytes) of per-thread cache used to offload the global "
+           "quarantine. Lower value may reduce memory usage but might increase "
+           "the contention on the global quarantine.")
+
+SCUDO_FLAG(int, quarantine_max_chunk_size, 0,
+           "Size (in bytes) up to which chunks will be quarantined (if lower "
+           "than or equal to).")
+
+SCUDO_FLAG(bool, dealloc_type_mismatch, false,
+           "Terminate on a type mismatch in allocation-deallocation functions, "
+           "eg: malloc/delete, new/free, new/delete[], etc.")
+
+SCUDO_FLAG(bool, delete_size_mismatch, true,
+           "Terminate on a size mismatch between a sized-delete and the actual "
+           "size of a chunk (as provided to new/new[]).")
+
+SCUDO_FLAG(bool, zero_contents, false, "Zero chunk contents on allocation.")
+
+SCUDO_FLAG(int, rss_limit_mb, -1,
+           "Enforce an upper limit (in megabytes) to the process RSS. The "
+           "allocator will terminate or return NULL when allocations are "
+           "attempted past that limit (depending on may_return_null). Negative "
+           "values disable the feature.")
+
+SCUDO_FLAG(bool, may_return_null, true,
+           "Indicate whether the allocator should terminate instead of "
+           "returning NULL in otherwise non-fatal error scenarios, eg: OOM, "
+           "invalid allocation alignments, etc.")
+
+SCUDO_FLAG(int, release_to_os_interval_ms, 5000,
+           "Interval (in milliseconds) at which to attempt release of unused "
+           "memory to the OS. Negative values disable the feature.")