[scudo] Reduce the scope of AllocAfterFork
`ScudoWrappersCppTest.AllocAfterFork` was failing obscurely sometimes.
Someone pointed us to Linux's `vm.max_map_count` that can be
significantly lower on some machines than others. It turned out that
on a machine with that setting set to 65530, some `ENOMEM` errors
would occur with `mmap` & `mprotect` during that specific test.
Reducing the number of times we fork, and the maximum size allocated
during that test makes it pass on those machines.
Differential Revision: https://reviews.llvm.org/D111342
GitOrigin-RevId: 6727832c324c1fb43946275d24e2931fde94bc0d
diff --git a/tests/wrappers_cpp_test.cpp b/tests/wrappers_cpp_test.cpp
index 1141967..5099e6d 100644
--- a/tests/wrappers_cpp_test.cpp
+++ b/tests/wrappers_cpp_test.cpp
@@ -130,10 +130,6 @@
}
#if !SCUDO_FUCHSIA
-// TODO(kostyak): for me, this test fails in a specific configuration when ran
-// by itself with some Scudo or GWP-ASan violation. Other people
-// can't seem to reproduce the failure. Consider skipping this in
-// the event it fails on the upstream bots.
TEST(ScudoWrappersCppTest, AllocAfterFork) {
std::atomic_bool Stop;
@@ -142,7 +138,7 @@
for (size_t N = 0; N < 5; N++) {
std::thread *T = new std::thread([&Stop] {
while (!Stop) {
- for (size_t SizeLog = 3; SizeLog <= 21; SizeLog++) {
+ for (size_t SizeLog = 3; SizeLog <= 20; SizeLog++) {
char *P = new char[1UL << SizeLog];
EXPECT_NE(P, nullptr);
// Make sure this value is not optimized away.
@@ -155,10 +151,10 @@
}
// Create a thread to fork and allocate.
- for (size_t N = 0; N < 100; N++) {
+ for (size_t N = 0; N < 50; N++) {
pid_t Pid;
if ((Pid = fork()) == 0) {
- for (size_t SizeLog = 3; SizeLog <= 21; SizeLog++) {
+ for (size_t SizeLog = 3; SizeLog <= 20; SizeLog++) {
char *P = new char[1UL << SizeLog];
EXPECT_NE(P, nullptr);
// Make sure this value is not optimized away.
