[GWP-ASan] Provide runtime configuration through an env var + sysprop.
This patch introduces GWP-ASan system properties and environment
variables to control the internal sampling rates of GWP-ASan. This can
be used for:
1. "Torture testing" the system, i.e. running it under an extremely
high sampling rate under GWP-ASan.
2. Increasing sampling remotely to allow further crash report
collection of rare issues.
There are three sets of system properites:
1. libc.debug.gwp_asan.*.system_default: Default values for native
executables and system apps.
2. libc.debug.gwp_asan.*.app_default: Default values for non-system
apps, and
3. libc.debug.gwp_asan.*.<basename/app_name>: Default values for an
individual app or native process.
There are three variables that can be changed:
1. The allocation sampling rate (default: 2500) - using the environment
variable GWP_ASAN_SAMPLE_RATE or the libc.debug.gwp_asan.sample_rate.*
system property.
2. The process sampling rate (default: 128 for system apps/processes, 1
for opted-in apps) - using the environment variable
GWP_ASAN_PROCESS_SAMPLING or the libc.debug.gwp_asan.process_sampling.*
system property,
3. The number of slots available (default: 32) - using the environment
variable GWP_ASAN_MAX_ALLOCS or the libc.debug.gwp_asan.max_allocs.*
system property.
If not specified, #3 will be calculated as a ratio of the default
|2500 SampleRate : 32 slots|. So, a sample rate of "1250" (i.e. twice as
frequent sampling) will result in a doubling of the max_allocs to "64".
Bug: 219651032
Test: atest bionic-unit-tests
Change-Id: Idb40a2a4d074e01ce3c4e635ad639a91a32d570f
diff --git a/libc/bionic/gwp_asan_wrappers.h b/libc/bionic/gwp_asan_wrappers.h
index c568681..219da9f 100644
--- a/libc/bionic/gwp_asan_wrappers.h
+++ b/libc/bionic/gwp_asan_wrappers.h
@@ -28,19 +28,20 @@
#pragma once
-#include <private/bionic_globals.h>
-#include <private/bionic_malloc_dispatch.h>
#include <stddef.h>
-// Enable GWP-ASan, used by android_mallopt.
-bool EnableGwpAsan(bool force_init);
+#include "gwp_asan/options.h"
+#include "platform/bionic/malloc.h"
+#include "private/bionic_globals.h"
+#include "private/bionic_malloc_dispatch.h"
+
+// Enable GWP-ASan, used by android_mallopt. Should always be called in a
+// single-threaded context.
+bool EnableGwpAsan(const android_mallopt_gwp_asan_options_t& options);
// Hooks for libc to possibly install GWP-ASan.
bool MaybeInitGwpAsanFromLibc(libc_globals* globals);
-// Maybe initialize GWP-ASan. Set force_init to true to bypass process sampling.
-bool MaybeInitGwpAsan(libc_globals* globals, bool force_init = false);
-
// Returns whether GWP-ASan is the provided dispatch table pointer. Used in
// heapprofd's signal-initialization sequence to determine the intermediate
// dispatch pointer to use when initing.