From e3b459a845f899136a20fd75e7d5904c11d5c9c9 Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Tue, 23 Feb 2021 10:03:30 -0500
Subject: [PATCH] Revert "temporary workarounds for bugs"

This reverts commit 1383b1629c1e086e3be439a9978d340b947260bb.
---
 h_malloc.c | 51 ++++++++-------------------------------------------
 1 file changed, 8 insertions(+), 43 deletions(-)

diff --git a/h_malloc.c b/h_malloc.c
index d97176d..bdc296a 100644
--- a/h_malloc.c
+++ b/h_malloc.c
@@ -76,10 +76,6 @@ static union {
 #ifdef USE_PKEY
         int metadata_pkey;
 #endif
-        bool zero_on_free;
-        bool purge_slabs;
-        bool region_quarantine_protect;
-        bool slot_randomize;
     };
     char padding[PAGE_SIZE];
 } ro __attribute__((aligned(PAGE_SIZE)));
@@ -351,7 +347,7 @@ static u64 get_mask(size_t slots) {
 }
 
 static size_t get_free_slot(struct random_state *rng, size_t slots, struct slab_metadata *metadata) {
-    if (ro.slot_randomize) {
+    if (SLOT_RANDOMIZE) {
         // randomize start location for linear search (uniform random choice is too slow)
         unsigned random_index = get_random_u16_uniform(rng, slots);
         unsigned first_bitmap = random_index / 64;
@@ -433,7 +429,7 @@ static void *slot_pointer(size_t size, void *slab, size_t slot) {
 }
 
 static void write_after_free_check(const char *p, size_t size) {
-    if (!WRITE_AFTER_FREE_CHECK || !ro.zero_on_free) {
+    if (!WRITE_AFTER_FREE_CHECK) {
         return;
     }
 
@@ -675,7 +671,7 @@ static inline void deallocate_small(void *p, const size_t *expected_size) {
             }
         }
 
-        if (ro.zero_on_free) {
+        if (ZERO_ON_FREE) {
             memset(p, 0, size - canary_size);
         }
     }
@@ -752,7 +748,7 @@ static inline void deallocate_small(void *p, const size_t *expected_size) {
         metadata->prev = NULL;
 
         if (c->empty_slabs_total + slab_size > max_empty_slabs_total) {
-            if (ro.purge_slabs && !memory_map_fixed(slab, slab_size)) {
+            if (!memory_map_fixed(slab, slab_size)) {
                 label_slab(slab, slab_size, class);
                 stats_slab_deallocate(c, slab_size);
                 enqueue_free_slab(c, metadata);
@@ -836,13 +832,9 @@ static void regions_quarantine_deallocate_pages(void *p, size_t size, size_t gua
         return;
     }
 
-    if (ro.region_quarantine_protect) {
-        if (unlikely(memory_map_fixed(p, size))) {
-            deallocate_pages(p, size, guard_size);
-            return;
-        }
-    } else {
-        madvise(p, size, MADV_DONTNEED);
+    if (unlikely(memory_map_fixed(p, size))) {
+        deallocate_pages(p, size, guard_size);
+        return;
     }
     memory_set_name(p, size, "malloc large quarantine");
 
@@ -1056,27 +1048,6 @@ static inline void enforce_init(void) {
     }
 }
 
-COLD static void handle_bugs(void) {
-    char path[256];
-    if (readlink("/proc/self/exe", path, sizeof(path)) == -1) {
-        return;
-    }
-
-    // Pixel 3, Pixel 3 XL, Pixel 3a and Pixel 3a XL camera provider
-    const char camera_provider[] = "/vendor/bin/hw/android.hardware.camera.provider@2.4-service_64";
-    if (strcmp(camera_provider, path) == 0) {
-        ro.zero_on_free = false;
-        ro.purge_slabs = false;
-        ro.region_quarantine_protect = false;
-    }
-
-    // DeviceDescriptor sorting wrongly relies on malloc addresses
-    const char audio_service[] = "/system/bin/audioserver";
-    if (strcmp(audio_service, path) == 0) {
-        ro.slot_randomize = false;
-    }
-}
-
 COLD static void init_slow_path(void) {
     static struct mutex lock = MUTEX_INITIALIZER;
 
@@ -1091,12 +1062,6 @@ COLD static void init_slow_path(void) {
     ro.metadata_pkey = pkey_alloc(0, 0);
 #endif
 
-    ro.purge_slabs = true;
-    ro.zero_on_free = ZERO_ON_FREE;
-    ro.region_quarantine_protect = true;
-    ro.slot_randomize = SLOT_RANDOMIZE;
-    handle_bugs();
-
     if (sysconf(_SC_PAGESIZE) != PAGE_SIZE) {
         fatal_error("runtime page size does not match compile-time page size which is not supported");
     }
@@ -1369,7 +1334,7 @@ EXPORT void *h_calloc(size_t nmemb, size_t size) {
     total_size = adjust_size_for_canaries(total_size);
     void *p = allocate(arena, total_size);
     thread_seal_metadata();
-    if (!ro.zero_on_free && likely(p != NULL) && total_size && total_size <= MAX_SLAB_SIZE_CLASS) {
+    if (!ZERO_ON_FREE && likely(p != NULL) && total_size && total_size <= MAX_SLAB_SIZE_CLASS) {
         memset(p, 0, total_size - canary_size);
     }
     return p;