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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:13:33 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:13:33 +0000
commit086c044dc34dfc0f74fbe41f4ecb402b2cd34884 (patch)
treea4f824bd33cb075dd5aa3eb5a0a94af221bbe83a /memory
parentAdding debian version 124.0.1-1. (diff)
downloadfirefox-086c044dc34dfc0f74fbe41f4ecb402b2cd34884.tar.xz
firefox-086c044dc34dfc0f74fbe41f4ecb402b2cd34884.zip
Merging upstream version 125.0.1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'memory')
-rw-r--r--memory/build/PHC.cpp21
1 files changed, 16 insertions, 5 deletions
diff --git a/memory/build/PHC.cpp b/memory/build/PHC.cpp
index 94cb5596a5..88c95743eb 100644
--- a/memory/build/PHC.cpp
+++ b/memory/build/PHC.cpp
@@ -603,7 +603,9 @@ class GMut {
// The mutex that protects the other members.
static Mutex sMutex MOZ_UNANNOTATED;
- GMut() : mRNG(RandomSeed<0>(), RandomSeed<1>()) { sMutex.Init(); }
+ // The RNG seeds here are poor, but non-reentrant since this can be called
+ // from malloc(). SetState() will reset the RNG later.
+ GMut() : mRNG(RandomSeed<1>(), RandomSeed<2>()) { sMutex.Init(); }
uint64_t Random64(GMutLock) { return mRNG.next(); }
@@ -865,12 +867,18 @@ class GMut {
void SetState(PHCState aState) {
if (mPhcState != PHCState::Enabled && aState == PHCState::Enabled) {
MutexAutoLock lock(GMut::sMutex);
+ // Reset the RNG at this point with a better seed.
+ ResetRNG();
GAtomic::Init(Rnd64ToDelay(mAvgFirstAllocDelay, Random64(lock)));
}
mPhcState = aState;
}
+ void ResetRNG() {
+ mRNG = non_crypto::XorShift128PlusRNG(RandomSeed<0>(), RandomSeed<1>());
+ }
+
void SetProbabilities(int64_t aAvgDelayFirst, int64_t aAvgDelayNormal,
int64_t aAvgDelayPageReuse) {
MutexAutoLock lock(GMut::sMutex);
@@ -885,15 +893,18 @@ class GMut {
uint64_t RandomSeed() {
// An older version of this code used RandomUint64() here, but on Mac that
// function uses arc4random(), which can allocate, which would cause
- // re-entry, which would be bad. So we just use time() and a local variable
- // address. These are mediocre sources of entropy, but good enough for PHC.
- static_assert(N == 0 || N == 1, "must be 0 or 1");
+ // re-entry, which would be bad. So we just use time(), a local variable
+ // address and a global variable address. These are mediocre sources of
+ // entropy, but good enough for PHC.
+ static_assert(N == 0 || N == 1 || N == 2, "must be 0, 1 or 2");
uint64_t seed;
if (N == 0) {
time_t t = time(nullptr);
seed = t ^ (t << 32);
- } else {
+ } else if (N == 1) {
seed = uintptr_t(&seed) ^ (uintptr_t(&seed) << 32);
+ } else {
+ seed = uintptr_t(&gConst) ^ (uintptr_t(&gConst) << 32);
}
return seed;
}