kiper220/mimalloc
1
0
Fork 0
mirror of https://github.com/microsoft/mimalloc.git synced 2025-07-06 19:38:41 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

updated random cookie generation using OS primitives and chacha20

Browse source
This commit is contained in:
daan 2019-12-22 17:07:01 -08:00
parent 36d168a2d9
commit ba87a39d9f
18 changed files with 378 additions and 97 deletions
Download patch file Download diff file Expand all files Collapse all files

77
src/init.c
View file

@ -85,7 +85,7 @@ const mi_heap_t _mi_heap_empty = {
ATOMIC_VAR_INIT(NULL),
0,
0,
0,
{ {0}, {0}, 0 },
0,
false
};
@ -116,7 +116,7 @@ mi_heap_t _mi_heap_main = {
#else
0xCDCDCDCDUL,
#endif
0, // random
{ {0}, {0}, 0 }, // random
0, // page count
false // can reclaim
};
@ -125,66 +125,6 @@ bool _mi_process_is_initialized = false; // set to `true` in `mi_process_init`.
mi_stats_t _mi_stats_main = { MI_STATS_NULL };
/* -----------------------------------------------------------
Initialization of random numbers
----------------------------------------------------------- */
#if defined(_WIN32)
#include <windows.h>
#elif defined(__APPLE__)
#include <mach/mach_time.h>
#else
#include <time.h>
#endif
uintptr_t _mi_random_shuffle(uintptr_t x) {
#if (MI_INTPTR_SIZE==8)
// by Sebastiano Vigna, see: <http://xoshiro.di.unimi.it/splitmix64.c>
x ^= x >> 30;
x *= 0xbf58476d1ce4e5b9UL;
x ^= x >> 27;
x *= 0x94d049bb133111ebUL;
x ^= x >> 31;
#elif (MI_INTPTR_SIZE==4)
// by Chris Wellons, see: <https://nullprogram.com/blog/2018/07/31/>
x ^= x >> 16;
x *= 0x7feb352dUL;
x ^= x >> 15;
x *= 0x846ca68bUL;
x ^= x >> 16;
#endif
return x;
}
uintptr_t _mi_random_init(uintptr_t seed /* can be zero */) {
#ifdef __wasi__ // no ASLR when using WebAssembly, and time granularity may be coarse
uintptr_t x;
arc4random_buf(&x, sizeof x);
#else
// Hopefully, ASLR makes our function address random
uintptr_t x = (uintptr_t)((void*)&_mi_random_init);
x ^= seed;
// xor with high res time
#if defined(_WIN32)
LARGE_INTEGER pcount;
QueryPerformanceCounter(&pcount);
x ^= (uintptr_t)(pcount.QuadPart);
#elif defined(__APPLE__)
x ^= (uintptr_t)mach_absolute_time();
#else
struct timespec time;
clock_gettime(CLOCK_MONOTONIC, &time);
x ^= (uintptr_t)time.tv_sec;
x ^= (uintptr_t)time.tv_nsec;
#endif
// and do a few randomization steps
uintptr_t max = ((x ^ (x >> 17)) & 0x0F) + 1;
for (uintptr_t i = 0; i < max; i++) {
x = _mi_random_shuffle(x);
}
#endif
return x;
}
/* -----------------------------------------------------------
Initialization and freeing of the thread local heaps
@ -214,8 +154,8 @@ static bool _mi_heap_init(void) {
mi_heap_t* heap = &td->heap;
memcpy(heap, &_mi_heap_empty, sizeof(*heap));
heap->thread_id = _mi_thread_id();
heap->random = _mi_random_init(heap->thread_id);
heap->cookie = ((uintptr_t)heap ^ _mi_heap_random(heap)) | 1;
_mi_random_init(&heap->random);
heap->cookie = _mi_heap_random_next(heap) | 1;
heap->tld = tld;
memset(tld, 0, sizeof(*tld));
tld->heap_backing = heap;
@ -451,16 +391,15 @@ void mi_process_init(void) mi_attr_noexcept {
// access _mi_heap_default before setting _mi_process_is_initialized to ensure
// that the TLS slot is allocated without getting into recursion on macOS
// when using dynamic linking with interpose.
mi_heap_t* h = mi_get_default_heap();
mi_get_default_heap();
_mi_process_is_initialized = true;
_mi_heap_main.thread_id = _mi_thread_id();
_mi_verbose_message("process init: 0x%zx\n", _mi_heap_main.thread_id);
uintptr_t random = _mi_random_init(_mi_heap_main.thread_id) ^ (uintptr_t)h;
#ifndef __APPLE__
_mi_heap_main.cookie = (uintptr_t)&_mi_heap_main ^ random;
_mi_random_init(&_mi_heap_main.random);
#ifndef __APPLE__ // TODO: fix this? cannot update cookie if allocation already happened..
_mi_heap_main.cookie = _mi_heap_random_next(&_mi_heap_main);
#endif
_mi_heap_main.random = _mi_random_shuffle(random);
mi_process_setup_auto_thread_done();
_mi_os_init();
#if (MI_DEBUG)