Delete ASAN

It hasn't been helpful enough to be justify the maintenance burden. What
actually does help is mprotect(), kprintf(), --ftrace and --strace which
can always be counted upon to work correctly. We aren't losing much with
this change. Support for ASAN on AARCH64 was never implemented. Applying
ASAN to the core libc runtimes was disabled many months ago. If there is
some way to have an ASAN runtime for user programs that is less invasive
we can potentially consider reintroducing support. But now is premature.

libc/runtime/clone.c

@@ -27,7 +27,6 @@
 #include "libc/calls/wincrash.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
-#include "libc/intrin/asan.internal.h"
 #include "libc/intrin/atomic.h"
 #include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/ulock.h"
@@ -751,13 +750,6 @@ errno_t clone(void *func, void *stk, size_t stksz, int flags, void *arg,
 
   if (!func) {
     rc = EINVAL;
-  } else if (IsAsan() &&
-             (((flags & CLONE_SETTLS) && !__asan_is_valid(tls, 64)) ||
-              ((flags & CLONE_PARENT_SETTID) &&
-               !__asan_is_valid(ptid, sizeof(int))) ||
-              ((flags & CLONE_CHILD_SETTID) &&
-               !__asan_is_valid(ctid, sizeof(int))))) {
-    rc = EFAULT;
   } else if (IsLinux()) {
     rc = CloneLinux(func, stk, stksz, flags, arg, tls, ptid, ctid);
   } else if (!IsTiny() &&

libc/runtime/cosmo.S

@@ -134,16 +134,6 @@ cosmo:	push	%rbp
 	pop	%rdi
 	.init.end 304,_init_tls
 
-#if IsAsan()
-	.init.start 305,_init_symbols
-	push	%rdi
-	push	%rsi
-	call	__init_symbols
-	pop	%rsi
-	pop	%rdi
-	.init.end 305,_init_symbols
-#endif
-
 #ifdef FTRACE
 	.init.start 306,_init_ftrace
 	push	%rdi

libc/runtime/enable_tls.c

@@ -20,8 +20,6 @@
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
-#include "libc/intrin/asan.internal.h"
-#include "libc/intrin/asancodes.h"
 #include "libc/intrin/atomic.h"
 #include "libc/intrin/dll.h"
 #include "libc/intrin/getenv.internal.h"
@@ -151,22 +149,12 @@ textstartup void __enable_tls(void) {
     mem = _weaken(_mapanon)(siz);
   }
 
-  if (IsAsan()) {
-    // poison the space between .tdata and .tbss
-    __asan_poison(mem + I(_tdata_size), I(_tbss_offset) - I(_tdata_size),
-                  kAsanProtected);
-  }
-
   struct CosmoTib *tib = (struct CosmoTib *)(mem + siz - sizeof(*tib));
   char *tls = mem + siz - sizeof(*tib) - I(_tls_size);
 
   // copy in initialized data section
   if (I(_tdata_size)) {
-    if (IsAsan()) {
-      __asan_memcpy(tls, _tdata_start, I(_tdata_size));
-    } else {
-      memcpy(tls, _tdata_start, I(_tdata_size));
-    }
+    memcpy(tls, _tdata_start, I(_tdata_size));
   }
 
 #elif defined(__aarch64__)

libc/runtime/mapstack.c

@@ -19,8 +19,6 @@
 #include "libc/calls/calls.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
-#include "libc/intrin/asan.internal.h"
-#include "libc/intrin/asancodes.h"
 #include "libc/runtime/memtrack.internal.h"
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/stack.h"
@@ -55,10 +53,6 @@ void *NewCosmoStack(void) {
                                   -1, 0, 0) != p) {
       notpossible;
     }
-    if (IsAsan()) {
-      __asan_poison(p + n - 16, 16, kAsanStackOverflow);
-      __asan_poison(p, getauxval(AT_PAGESZ), kAsanStackOverflow);
-    }
     return p;
   } else {
     return 0;

libc/runtime/symbols.c

@@ -23,7 +23,6 @@
 #include "libc/runtime/symbols.internal.h"
 
 void __init_symbols(void) {
-  if (__strace > 0 || (IsAsan() && _weaken(__die))) {
+  if (__strace > 0)
     GetSymbolTable();
-  }
 }

libc/runtime/zipos-open.c

@@ -26,7 +26,6 @@
 #include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
-#include "libc/intrin/asan.internal.h"
 #include "libc/intrin/atomic.h"
 #include "libc/intrin/cmpxchg.h"
 #include "libc/intrin/directmap.internal.h"
@@ -94,10 +93,6 @@ void __zipos_drop(struct ZiposHandle *h) {
     return;
   }
   atomic_thread_fence(memory_order_acquire);
-  if (IsAsan()) {
-    __asan_poison((char *)h + sizeof(struct ZiposHandle),
-                  h->mapsize - sizeof(struct ZiposHandle), kAsanHeapFree);
-  }
   __zipos_lock();
   do
     h->next = h->zipos->freelist;
@@ -125,12 +120,6 @@ StartOver:
     h = __zipos_mmap_space(mapsize);
   }
   __zipos_unlock();
-  if (IsAsan()) {
-    __asan_unpoison((char *)h, sizeof(struct ZiposHandle) + size);
-    __asan_poison((char *)h + sizeof(struct ZiposHandle) + size,
-                  mapsize - (sizeof(struct ZiposHandle) + size),
-                  kAsanHeapOverrun);
-  }
   if (h) {
     atomic_store_explicit(&h->refs, 0, memory_order_relaxed);
     h->size = size;