Auto merge of #18732 - bholley:revert_mprotect_diagnostics, r=bholley

Revert #18668 - Add mprotect diagnostics for HashMap crash (except for round-up-to-page behavior).

These diagnostics have served their purpose, time to remove them.

https://bugzilla.mozilla.org/show_bug.cgi?id=1403397

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components/hashglobe/src/hash_map.rs

@@ -1027,12 +1027,6 @@ impl<K, V, S> HashMap<K, V, S>
         self.table.size()
     }
 
-    /// Access to the raw buffer backing this hashmap.
-    pub fn raw_buffer(&self) -> (*const (), usize) {
-        assert!(self.raw_capacity() != 0);
-        self.table.raw_buffer()
-    }
-
     /// Returns true if the map contains no elements.
     ///
     /// # Examples

components/hashglobe/src/lib.rs

@@ -13,7 +13,6 @@ extern crate heapsize;
 pub mod alloc;
 pub mod hash_map;
 pub mod hash_set;
-pub mod protected;
 mod shim;
 mod table;
 
@@ -52,6 +51,3 @@ impl fmt::Display for FailedAllocationError {
         self.reason.fmt(f)
     }
 }
-
-// The size of memory pages on this system. Set when initializing geckolib.
-pub static SYSTEM_PAGE_SIZE: ::std::sync::atomic::AtomicUsize = ::std::sync::atomic::ATOMIC_USIZE_INIT;

components/hashglobe/src/table.rs

@@ -777,7 +777,7 @@ impl<K, V> RawTable<K, V> {
 
 
         // FORK NOTE: Uses alloc shim instead of Heap.alloc
-        let buffer = alloc(round_up_to_page_size(size), alignment);
+        let buffer = alloc(size, alignment);
 
         if buffer.is_null() {
 
@@ -813,24 +813,6 @@ impl<K, V> RawTable<K, V> {
         }
     }
 
-    /// Access to the raw buffer backing this table.
-    pub fn raw_buffer(&self) -> (*const (), usize) {
-        debug_assert!(self.capacity() != 0);
-
-        let buffer = self.hashes.ptr() as *const ();
-        let size = {
-            let hashes_size = self.capacity() * size_of::<HashUint>();
-            let pairs_size = self.capacity() * size_of::<(K, V)>();
-            let (_, _, size, _) = calculate_allocation(hashes_size,
-                                                       align_of::<HashUint>(),
-                                                       pairs_size,
-                                                       align_of::<(K, V)>());
-            round_up_to_page_size(size)
-        };
-        (buffer, size)
-    }
-
-
     /// Creates a new raw table from a given capacity. All buckets are
     /// initially empty.
     pub fn new(capacity: usize) -> Result<RawTable<K, V>, FailedAllocationError> {
@@ -1219,19 +1201,3 @@ impl<K, V> Drop for RawTable<K, V> {
         }
     }
 }
-
-// Force all allocations to fill their pages for the duration of the mprotect
-// experiment.
-#[inline]
-fn round_up_to_page_size(size: usize) -> usize {
-    let page_size = ::SYSTEM_PAGE_SIZE.load(::std::sync::atomic::Ordering::Relaxed);
-    debug_assert!(page_size != 0);
-    let mut result = size;
-    let remainder = size % page_size;
-    if remainder != 0 {
-        result += page_size - remainder;
-    }
-    debug_assert!(result % page_size == 0);
-    debug_assert!(result - size < page_size);
-    result
-}

components/malloc_size_of/lib.rs

@@ -339,25 +339,6 @@ impl<K, V, S> MallocSizeOf for hashglobe::hash_map::HashMap<K, V, S>
     }
 }
 
-impl<K, V, S> MallocShallowSizeOf for hashglobe::protected::ProtectedHashMap<K, V, S>
-    where K: Eq + Hash,
-          S: BuildHasher
-{
-    fn shallow_size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
-        self.inner().shallow_size_of(ops)
-    }
-}
-
-impl<K, V, S> MallocSizeOf for hashglobe::protected::ProtectedHashMap<K, V, S>
-    where K: Eq + Hash + MallocSizeOf,
-          V: MallocSizeOf,
-          S: BuildHasher,
-{
-    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
-        self.inner().size_of(ops)
-    }
-}
-
 // XXX: we don't want MallocSizeOf to be defined for Rc and Arc. If negative
 // trait bounds are ever allowed, this code should be uncommented.
 // (We do have a compile-fail test for this:

components/style/gecko/generated/bindings.rs

@@ -1562,14 +1562,6 @@ extern "C" {
 extern "C" {
     pub fn Gecko_GetSystemPageSize() -> usize;
 }
-extern "C" {
-    pub fn Gecko_ProtectBuffer(buffer: *mut ::std::os::raw::c_void,
-                               size: usize);
-}
-extern "C" {
-    pub fn Gecko_UnprotectBuffer(buffer: *mut ::std::os::raw::c_void,
-                                 size: usize);
-}
 extern "C" {
     pub fn Gecko_Construct_Default_nsStyleFont(ptr: *mut nsStyleFont,
                                                pres_context:
@@ -2999,10 +2991,6 @@ extern "C" {
                                         *const ServoRawOffsetArc<RustString>)
      -> ServoRawOffsetArc<RustString>;
 }
-extern "C" {
-    pub fn Servo_CorruptRuleHashAndCrash(set: RawServoStyleSetBorrowed,
-                                         index: usize);
-}
 extern "C" {
     pub fn Gecko_CreateCSSErrorReporter(sheet: *mut ServoStyleSheet,
                                         loader: *mut Loader, uri: *mut nsIURI)