[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/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 38168ee..9744968 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -326,12 +326,12 @@
return LimitEnable(arg, arg_size);
}
if (opcode == M_INITIALIZE_GWP_ASAN) {
- if (arg == nullptr || arg_size != sizeof(bool)) {
+ if (arg == nullptr || arg_size != sizeof(android_mallopt_gwp_asan_options_t)) {
errno = EINVAL;
return false;
}
- return EnableGwpAsan(*reinterpret_cast<bool*>(arg));
+ return EnableGwpAsan(*reinterpret_cast<android_mallopt_gwp_asan_options_t*>(arg));
}
errno = ENOTSUP;
return false;