Revert "[msan] Check qsort input." and "[msan] Intercept qsort, qsort_r."

Temporarily revert the qsort changes because they fail to build on bots
that build with modules:

> error: thread-local storage is not supported for the current
> target (iossim)

http://green.lab.llvm.org/green/job/clang-stage2-Rthinlto/1820/console
http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/4983/console

This reverts commit ddf897fc80499ece298bc33201db6b697d2af50e.
This reverts commit 07861e955d0095f25639d84c5726c73b528567cb.

3 files changed, 0 insertions, 169 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 68a9db5bba7..af301a1a689 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -9639,93 +9639,6 @@ INTERCEPTOR(int, getentropy, void *buf, SIZE_T buflen) {
 #define INIT_GETENTROPY
 #endif
 
-#if SANITIZER_INTERCEPT_QSORT
-// Glibc qsort uses a temporary buffer allocated either on stack or on heap.
-// Poisoned memory from there may get copied into the comparator arguments,
-// where it needs to be dealt with. But even that is not enough - the results of
-// the sort may be copied into the input/output array based on the results of
-// the comparator calls, but directly from the temp memory, bypassing the
-// unpoisoning done in wrapped_qsort_compar. We deal with this by, again,
-// unpoisoning the entire array after the sort is done.
-//
-// We can not check that the entire array is initialized at the beginning. IMHO,
-// it's fine for parts of the sorted objects to contain uninitialized memory,
-// ex. as padding in structs.
-typedef int (*qsort_compar_f)(const void *, const void *);
-static THREADLOCAL qsort_compar_f qsort_compar;
-static THREADLOCAL SIZE_T qsort_size;
-int wrapped_qsort_compar(const void *a, const void *b) {
-  COMMON_INTERCEPTOR_UNPOISON_PARAM(2);
-  COMMON_INTERCEPTOR_INITIALIZE_RANGE(a, qsort_size);
-  COMMON_INTERCEPTOR_INITIALIZE_RANGE(b, qsort_size);
-  return qsort_compar(a, b);
-}
-
-INTERCEPTOR(void, qsort, void *base, SIZE_T nmemb, SIZE_T size,
-            qsort_compar_f compar) {
-  void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, qsort, base, nmemb, size, compar);
-  // Run the comparator over all array elements to detect any memory issues.
-  for (SIZE_T i = 0; i < nmemb; ++i) {
-    void *p = (void *)((char *)base + i * size);
-    COMMON_INTERCEPTOR_UNPOISON_PARAM(2);
-    // Compare each element with itself to trigger an equality check, which
-    // typically requires the comparator to look as many of the object fields as
-    // possible.
-    compar(p, p);
-  }
-  qsort_compar_f old_compar = qsort_compar;
-  qsort_compar = compar;
-  SIZE_T old_size = qsort_size;
-  qsort_size = size;
-  REAL(qsort)(base, nmemb, size, wrapped_qsort_compar);
-  qsort_compar = old_compar;
-  qsort_size = old_size;
-  COMMON_INTERCEPTOR_WRITE_RANGE(ctx, base, nmemb * size);
-}
-#define INIT_QSORT COMMON_INTERCEPT_FUNCTION(qsort)
-#else
-#define INIT_QSORT
-#endif
-
-#if SANITIZER_INTERCEPT_QSORT_R
-typedef int (*qsort_r_compar_f)(const void *, const void *, void *);
-static THREADLOCAL qsort_r_compar_f qsort_r_compar;
-static THREADLOCAL SIZE_T qsort_r_size;
-int wrapped_qsort_r_compar(const void *a, const void *b, void *arg) {
-  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
-  COMMON_INTERCEPTOR_INITIALIZE_RANGE(a, qsort_r_size);
-  COMMON_INTERCEPTOR_INITIALIZE_RANGE(b, qsort_r_size);
-  return qsort_r_compar(a, b, arg);
-}
-
-INTERCEPTOR(void, qsort_r, void *base, SIZE_T nmemb, SIZE_T size,
-            qsort_r_compar_f compar, void *arg) {
-  void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, qsort_r, base, nmemb, size, compar, arg);
-  // Run the comparator over all array elements to detect any memory issues.
-  for (SIZE_T i = 0; i < nmemb; ++i) {
-    void *p = (void *)((char *)base + i * size);
-    COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
-    // Compare each element with itself to trigger an equality check, which
-    // typically requires the comparator to look as many of the object fields as
-    // possible.
-    compar(p, p, arg);
-  }
-  qsort_r_compar_f old_compar = qsort_r_compar;
-  qsort_r_compar = compar;
-  SIZE_T old_size = qsort_r_size;
-  qsort_r_size = size;
-  REAL(qsort_r)(base, nmemb, size, wrapped_qsort_r_compar, arg);
-  qsort_r_compar = old_compar;
-  qsort_r_size = old_size;
-  COMMON_INTERCEPTOR_WRITE_RANGE(ctx, base, nmemb * size);
-}
-#define INIT_QSORT_R COMMON_INTERCEPT_FUNCTION(qsort_r)
-#else
-#define INIT_QSORT_R
-#endif
-
 static void InitializeCommonInterceptors() {
 #if SI_POSIX
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
@@ -10027,8 +9940,6 @@ static void InitializeCommonInterceptors() {
   INIT_CRYPT;
   INIT_CRYPT_R;
   INIT_GETENTROPY;
-  INIT_QSORT;
-  INIT_QSORT_R;
 
   INIT___PRINTF_CHK;
 }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 697cdfc063f..61a6b82ef81 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -575,7 +575,5 @@
 #define SANITIZER_INTERCEPT_ATEXIT SI_NETBSD
 #define SANITIZER_INTERCEPT_PTHREAD_ATFORK SI_NETBSD
 #define SANITIZER_INTERCEPT_GETENTROPY SI_FREEBSD
-#define SANITIZER_INTERCEPT_QSORT SI_POSIX
-#define SANITIZER_INTERCEPT_QSORT_R (SI_LINUX && !SI_ANDROID)
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H
diff --git a/compiler-rt/test/msan/qsort.cpp b/compiler-rt/test/msan/qsort.cpp
deleted file mode 100644
index cf754012b22..00000000000
--- a/compiler-rt/test/msan/qsort.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-// RUN: %clangxx_msan -O0 -g %s -o %t && %run %t
-// RUN: %clangxx_msan -DPOISON -O0 -g %s -o %t && not %run %t 2>&1 | FileCheck %s
-
-#include <assert.h>
-#include <errno.h>
-#include <glob.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <sanitizer/msan_interface.h>
-
-constexpr size_t kSize1 = 27;
-constexpr size_t kSize2 = 7;
-
-bool seen2;
-
-void dummy(long a, long b, long c, long d, long e) {}
-
-void poison_stack_and_param() {
-  char x[10000];
-  int y;
-  dummy(y, y, y, y, y);
-}
-
-__attribute__((always_inline)) int cmp(long a, long b) {
-  if (a < b)
-    return -1;
-  else if (a > b)
-    return 1;
-  else
-    return 0;
-}
-
-int compar2(const void *a, const void *b) {
-  assert(a);
-  assert(b);
-  __msan_check_mem_is_initialized(a, sizeof(long));
-  __msan_check_mem_is_initialized(b, sizeof(long));
-  seen2 = true;
-  poison_stack_and_param();
-  return cmp(*(long *)a, *(long *)b);
-}
-
-int compar1(const void *a, const void *b) {
-  assert(a);
-  assert(b);
-  __msan_check_mem_is_initialized(a, sizeof(long));
-  __msan_check_mem_is_initialized(b, sizeof(long));
-
-  long *p = new long[kSize2];
-  // kind of random
-  for (int i = 0; i < kSize2; ++i)
-    p[i] = i * 2 + (i % 3 - 1) * 3;
-  qsort(p, kSize1, sizeof(long), compar2);
-  __msan_check_mem_is_initialized(p, sizeof(long) * kSize2);
-  delete[] p;
-
-  poison_stack_and_param();
-  return cmp(*(long *)a, *(long *)b);
-}
-
-int main(int argc, char *argv[]) {
-  long *p = new long[kSize1];
-  // kind of random
-  for (int i = 0; i < kSize1; ++i)
-    p[i] = i * 2 + (i % 3 - 1) * 3;
-  poison_stack_and_param();
-#ifdef POISON
-  __msan_poison(p + 1, sizeof(long));
-  // CHECK: Uninitialized bytes in __msan_check_mem_is_initialized at offset 0 inside [{{.*}}, 8)
-#endif
-  qsort(p, kSize1, sizeof(long), compar1);
-  __msan_check_mem_is_initialized(p, sizeof(long) * kSize1);
-  assert(seen2);
-  delete[] p;
-  return 0;
-}