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/*
* Copyright (C) 2022 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "SecureARM64EHashPins.h"
#if CPU(ARM64E) && ENABLE(JIT)
namespace JSC {
ALWAYS_INLINE uint64_t SecureARM64EHashPins::keyForCurrentThread()
{
uint64_t result;
asm (
"mrs %x[result], TPIDRRO_EL0"
: [result] "=r" (result)
:
:
);
return result + 1;
}
template <typename Function>
ALWAYS_INLINE void SecureARM64EHashPins::forEachPage(Function function)
{
for (Page* page = firstPage(); page; page = page->next) {
RELEASE_ASSERT(isJITPC(page));
if (function(*page) == IterationStatus::Done)
return;
}
}
template <typename Function>
ALWAYS_INLINE void SecureARM64EHashPins::forEachEntry(Function function)
{
size_t baseIndex = 0;
forEachPage([&] (Page& page) {
IterationStatus iterationStatus = IterationStatus::Continue;
page.forEachSetBit([&] (size_t bitIndex) {
Entry& entry = page.fastEntryUnchecked(bitIndex);
ASSERT(isJITPC(&entry));
size_t index = baseIndex + bitIndex;
iterationStatus = function(page, entry, index);
return iterationStatus;
});
baseIndex += numEntriesPerPage;
return iterationStatus;
});
}
ALWAYS_INLINE auto SecureARM64EHashPins::findFirstEntry() -> FindResult
{
uint64_t key = keyForCurrentThread();
// We can call this concurrently to the bit vector being modified
// since we either call this when we're locked, or we call it when
// we know the entry already exists. When the entry already exists,
// we know that the bit can't get flipped spuriously during concurrent
// modification, so we're guaranteed to find the value. We might see
// an entry as it's being written to, but that's also fine, since it
// won't have our same key. It'll either be zero, or a different key.
FindResult result;
forEachEntry([&] (Page& page, Entry& entry, size_t index) {
if (entry.key == key) {
result.entry = &entry;
result.page = &page;
result.index = index;
return IterationStatus::Done;
}
return IterationStatus::Continue;
});
return result;
}
ALWAYS_INLINE uint64_t SecureARM64EHashPins::pinForCurrentThread()
{
return findFirstEntry().entry->pin;
}
} // namespace JSC
#endif // CPU(ARM64E) && ENABLE(JIT)