[Python-checkins] [3.6] bpo-35214: Initial clang MemorySanitizer support (GH-10479) (GH-10493)
Gregory P. Smith
webhook-mailer at python.org
Mon Nov 12 19:10:35 EST 2018
https://github.com/python/cpython/commit/3b5b1c0931cd32253bbf2f3bd74e90ff821e026e
commit: 3b5b1c0931cd32253bbf2f3bd74e90ff821e026e
branch: 3.6
author: Gregory P. Smith <greg at krypto.org>
committer: GitHub <noreply at github.com>
date: 2018-11-12T16:10:21-08:00
summary:
[3.6] bpo-35214: Initial clang MemorySanitizer support (GH-10479) (GH-10493)
Adds configure flags for msan and ubsan builds to make it easier to enable.
These also encode the detail that address sanitizer and memory sanitizer
should disable pymalloc.
Define MEMORY_SANITIZER when appropriate at build time and adds workarounds
to existing code to mark things as initialized where the sanitizer is otherwise unable to
determine that. This lets our build succeed under the memory sanitizer. not all tests
pass without sanitizer failures yet but we're in pretty good shape after this.
(cherry picked from commit 1584a0081500d35dc93ff88e5836df35faf3e3e2)
Contributed by Gregory P. Smith [Google LLC]
Also includes a whitespace fix from make patchcheck to _posixsubprocess.c - unrelated to the main change that makes the CI happy so I'm just doing it now rather than creating a separate PR.
files:
A Misc/NEWS.d/next/Core and Builtins/2018-11-12-11-38-06.bpo-35214.PCHKbX.rst
M Include/Python.h
M Modules/_ctypes/callproc.c
M Modules/_posixsubprocess.c
M Modules/faulthandler.c
M Python/pymath.c
M Python/random.c
M configure
M configure.ac
diff --git a/Include/Python.h b/Include/Python.h
index 6177bad869c9..565f34a371f5 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -53,6 +53,15 @@
#include "pyport.h"
#include "pymacro.h"
+/* A convenient way for code to know if clang's memory sanitizer is enabled. */
+#if defined(__has_feature)
+# if __has_feature(memory_sanitizer)
+# if !defined(MEMORY_SANITIZER)
+# define MEMORY_SANITIZER
+# endif
+# endif
+#endif
+
#include "pyatomic.h"
/* Debug-mode build with pymalloc implies PYMALLOC_DEBUG.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-11-12-11-38-06.bpo-35214.PCHKbX.rst b/Misc/NEWS.d/next/Core and Builtins/2018-11-12-11-38-06.bpo-35214.PCHKbX.rst
new file mode 100644
index 000000000000..c7842f331698
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-11-12-11-38-06.bpo-35214.PCHKbX.rst
@@ -0,0 +1,4 @@
+The interpreter and extension modules have had annotations added so that
+they work properly under clang's Memory Sanitizer. A new configure flag
+--with-memory-sanitizer has been added to make test builds of this nature
+easier to perform.
diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index b8c2c746a0fe..0e1f065e19a4 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -75,6 +75,10 @@
#include <alloca.h>
#endif
+#ifdef MEMORY_SANITIZER
+#include <sanitizer/msan_interface.h>
+#endif
+
#if defined(_DEBUG) || defined(__MINGW32__)
/* Don't use structured exception handling on Windows if this is defined.
MingW, AFAIK, doesn't support it.
@@ -1136,6 +1140,13 @@ PyObject *_ctypes_callproc(PPROC pProc,
rtype = _ctypes_get_ffi_type(restype);
resbuf = alloca(max(rtype->size, sizeof(ffi_arg)));
+#ifdef MEMORY_SANITIZER
+ /* ffi_call actually initializes resbuf, but from asm, which
+ * MemorySanitizer can't detect. Avoid false positives from MSan. */
+ if (resbuf != NULL) {
+ __msan_unpoison(resbuf, max(rtype->size, sizeof(ffi_arg)));
+ }
+#endif
avalues = (void **)alloca(sizeof(void *) * argcount);
atypes = (ffi_type **)alloca(sizeof(ffi_type *) * argcount);
if (!resbuf || !avalues || !atypes) {
diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index fe0e554618aa..fe519dea9c54 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -21,6 +21,10 @@
#include <dirent.h>
#endif
+#ifdef MEMORY_SANITIZER
+# include <sanitizer/msan_interface.h>
+#endif
+
#if defined(__ANDROID__) && __ANDROID_API__ < 21 && !defined(SYS_getdents64)
# include <sys/linux-syscalls.h>
# define SYS_getdents64 __NR_getdents64
@@ -287,6 +291,9 @@ _close_open_fds_safe(int start_fd, PyObject* py_fds_to_keep)
sizeof(buffer))) > 0) {
struct linux_dirent64 *entry;
int offset;
+#ifdef MEMORY_SANITIZER
+ __msan_unpoison(buffer, bytes);
+#endif
for (offset = 0; offset < bytes; offset += entry->d_reclen) {
int fd;
entry = (struct linux_dirent64 *)(buffer + offset);
@@ -791,11 +798,11 @@ static PyMethodDef module_methods[] = {
static struct PyModuleDef _posixsubprocessmodule = {
- PyModuleDef_HEAD_INIT,
- "_posixsubprocess",
- module_doc,
- -1, /* No memory is needed. */
- module_methods,
+ PyModuleDef_HEAD_INIT,
+ "_posixsubprocess",
+ module_doc,
+ -1, /* No memory is needed. */
+ module_methods,
};
PyMODINIT_FUNC
diff --git a/Modules/faulthandler.c b/Modules/faulthandler.c
index 227424f8bbaa..890c64577cec 100644
--- a/Modules/faulthandler.c
+++ b/Modules/faulthandler.c
@@ -1393,7 +1393,7 @@ void _PyFaulthandler_Fini(void)
#ifdef HAVE_SIGALTSTACK
if (stack.ss_sp != NULL) {
/* Fetch the current alt stack */
- stack_t current_stack;
+ stack_t current_stack = {};
if (sigaltstack(NULL, ¤t_stack) == 0) {
if (current_stack.ss_sp == stack.ss_sp) {
/* The current alt stack is the one that we installed.
diff --git a/Python/pymath.c b/Python/pymath.c
index 6799d200caf6..c1606bd6d1da 100644
--- a/Python/pymath.c
+++ b/Python/pymath.c
@@ -17,7 +17,9 @@ double _Py_force_double(double x)
/* inline assembly for getting and setting the 387 FPU control word on
gcc/x86 */
-
+#ifdef MEMORY_SANITIZER
+__attribute__((no_sanitize_memory))
+#endif
unsigned short _Py_get_387controlword(void) {
unsigned short cw;
__asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
diff --git a/Python/random.c b/Python/random.c
index c62cbeb4ecb7..8f6670457f3f 100644
--- a/Python/random.c
+++ b/Python/random.c
@@ -20,6 +20,10 @@
# endif
#endif
+#ifdef MEMORY_SANITIZER
+# include <sanitizer/msan_interface.h>
+#endif
+
#ifdef Py_DEBUG
int _Py_HashSecret_Initialized = 0;
#else
@@ -143,6 +147,11 @@ py_getrandom(void *buffer, Py_ssize_t size, int blocking, int raise)
else {
n = syscall(SYS_getrandom, dest, n, flags);
}
+# ifdef MEMORY_SANITIZER
+ if (n > 0) {
+ __msan_unpoison(dest, n);
+ }
+# endif
#endif
if (n < 0) {
diff --git a/configure b/configure
index 75a80a797d34..9b137c72603a 100755
--- a/configure
+++ b/configure
@@ -822,6 +822,8 @@ enable_optimizations
with_lto
with_hash_algorithm
with_address_sanitizer
+with_memory_sanitizer
+with_undefined_behavior_sanitizer
with_libs
with_system_expat
with_system_ffi
@@ -1520,7 +1522,10 @@ Optional Packages:
--with-hash-algorithm=[fnv|siphash24]
select hash algorithm
--with-address-sanitizer
- enable AddressSanitizer
+ enable AddressSanitizer (asan)
+ --with-memory-sanitizer enable MemorySanitizer (msan)
+ --with-undefined-behavior-sanitizer
+ enable UndefinedBehaviorSanitizer (ubsan)
--with-libs='lib1 ...' link against additional libs
--with-system-expat build pyexpat module using an installed expat
library
@@ -9926,6 +9931,44 @@ if test "${with_address_sanitizer+set}" = set; then :
$as_echo "$withval" >&6; }
BASECFLAGS="-fsanitize=address -fno-omit-frame-pointer $BASECFLAGS"
LDFLAGS="-fsanitize=address $LDFLAGS"
+# ASan works by controlling memory allocation, our own malloc interferes.
+with_pymalloc="no"
+
+else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-memory-sanitizer" >&5
+$as_echo_n "checking for --with-memory-sanitizer... " >&6; }
+
+# Check whether --with-memory_sanitizer was given.
+if test "${with_memory_sanitizer+set}" = set; then :
+ withval=$with_memory_sanitizer;
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $withval" >&5
+$as_echo "$withval" >&6; }
+BASECFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer $BASECFLAGS"
+LDFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 $LDFLAGS"
+# MSan works by controlling memory allocation, our own malloc interferes.
+with_pymalloc="no"
+
+else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-undefined-behavior-sanitizer" >&5
+$as_echo_n "checking for --with-undefined-behavior-sanitizer... " >&6; }
+
+# Check whether --with-undefined_behavior_sanitizer was given.
+if test "${with_undefined_behavior_sanitizer+set}" = set; then :
+ withval=$with_undefined_behavior_sanitizer;
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $withval" >&5
+$as_echo "$withval" >&6; }
+BASECFLAGS="-fsanitize=undefined $BASECFLAGS"
+LDFLAGS="-fsanitize=undefined $LDFLAGS"
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
diff --git a/configure.ac b/configure.ac
index b411c3e8f6f1..f9d406e5e812 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2833,11 +2833,37 @@ esac
AC_MSG_CHECKING(for --with-address-sanitizer)
AC_ARG_WITH(address_sanitizer,
AS_HELP_STRING([--with-address-sanitizer],
- [enable AddressSanitizer]),
+ [enable AddressSanitizer (asan)]),
[
AC_MSG_RESULT($withval)
BASECFLAGS="-fsanitize=address -fno-omit-frame-pointer $BASECFLAGS"
LDFLAGS="-fsanitize=address $LDFLAGS"
+# ASan works by controlling memory allocation, our own malloc interferes.
+with_pymalloc="no"
+],
+[AC_MSG_RESULT(no)])
+
+AC_MSG_CHECKING(for --with-memory-sanitizer)
+AC_ARG_WITH(memory_sanitizer,
+ AS_HELP_STRING([--with-memory-sanitizer],
+ [enable MemorySanitizer (msan)]),
+[
+AC_MSG_RESULT($withval)
+BASECFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer $BASECFLAGS"
+LDFLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 $LDFLAGS"
+# MSan works by controlling memory allocation, our own malloc interferes.
+with_pymalloc="no"
+],
+[AC_MSG_RESULT(no)])
+
+AC_MSG_CHECKING(for --with-undefined-behavior-sanitizer)
+AC_ARG_WITH(undefined_behavior_sanitizer,
+ AS_HELP_STRING([--with-undefined-behavior-sanitizer],
+ [enable UndefinedBehaviorSanitizer (ubsan)]),
+[
+AC_MSG_RESULT($withval)
+BASECFLAGS="-fsanitize=undefined $BASECFLAGS"
+LDFLAGS="-fsanitize=undefined $LDFLAGS"
],
[AC_MSG_RESULT(no)])
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