<div dir="ltr"><br><div class="gmail_extra"><div class="gmail_quote">On Tue, Oct 15, 2013 at 3:31 PM, Dmitry Vyukov <span dir="ltr"><<a href="mailto:dvyukov@google.com" target="_blank">dvyukov@google.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: dvyukov<br>
Date: Tue Oct 15 06:31:51 2013<br>
New Revision: 192686<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=192686&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=192686&view=rev</a><br>
Log:<br>
tsan: implement internal syscall-based versions of sigaction/sigprocmask<br>
use them in stoptheworld<br>
fixes applications that intercept sigaction/sigprocmask<br>
<br>
<br>
<br>
Modified:<br>
compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc<br>
compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc<br>
compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h<br>
compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc?rev=192686&r1=192685&r2=192686&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc?rev=192686&r1=192685&r2=192686&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc Tue Oct 15 06:31:51 2013<br>
@@ -37,6 +37,7 @@<br>
#if SANITIZER_LINUX<br>
<br>
#include "sanitizer_libc.h"<br>
+#include "sanitizer_linux.h"<br>
<br>
#define PRE_SYSCALL(name) \<br>
SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_syscall_pre_impl_##name<br>
@@ -103,10 +104,6 @@ struct sanitizer_kernel_sockaddr {<br>
char sa_data[14];<br>
};<br>
<br>
-// Real sigset size is always passed as a syscall argument.<br>
-// Declare it "void" to catch sizeof(kernel_sigset_t).<br>
-typedef void kernel_sigset_t;<br>
-<br>
static void kernel_write_iovec(const __sanitizer_iovec *iovec,<br>
SIZE_T iovlen, SIZE_T maxlen) {<br>
for (SIZE_T i = 0; i < iovlen && maxlen; ++i) {<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc?rev=192686&r1=192685&r2=192686&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc?rev=192686&r1=192685&r2=192686&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc Tue Oct 15 06:31:51 2013<br>
@@ -602,6 +602,31 @@ uptr internal_sigaltstack(const struct s<br>
return internal_syscall(__NR_sigaltstack, ss, oss);<br>
}<br>
<br>
+uptr internal_sigaction(int signum, const kernel_sigaction_t *act,<br>
+ struct kernel_sigaction_t *oldact) {<br>
+ return internal_syscall(__NR_rt_sigaction, signum, act, oldact,<br>
+ sizeof(kernel_sigset_t));<br>
+}<br>
+<br>
+uptr internal_sigprocmask(int how, kernel_sigset_t *set,<br>
+ kernel_sigset_t *oldset) {<br>
+ return internal_syscall(__NR_rt_sigprocmask, (uptr)how, &set->sig[0],<br>
+ &oldset->sig[0], sizeof(kernel_sigset_t));<br>
+}<br>
+<br>
+void internal_sigfillset(kernel_sigset_t *set) {<br>
+ internal_memset(set, 0xff, sizeof(*set));<br>
+}<br>
+<br>
+void internal_sigdelset(kernel_sigset_t *set, int signum) {<br>
+ signum -= 1;<br>
+ CHECK_GE(signum, 0);<br>
+ CHECK_LT(signum, sizeof(*set) * 8);<br>
+ const uptr idx = signum / (sizeof(set->sig[0]) * 8);<br>
+ const uptr bit = signum % (sizeof(set->sig[0]) * 8);<br>
+ set->sig[idx] &= ~(1 << bit);<br>
+}<br>
+<br>
// ThreadLister implementation.<br>
ThreadLister::ThreadLister(int pid)<br>
: pid_(pid),<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h?rev=192686&r1=192685&r2=192686&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h?rev=192686&r1=192685&r2=192686&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h Tue Oct 15 06:31:51 2013<br>
@@ -20,17 +20,39 @@<br>
<br>
struct link_map; // Opaque type returned by dlopen().<br>
struct sigaltstack;<br>
+typedef struct siginfo siginfo_t;<br>
<br>
namespace __sanitizer {<br>
// Dirent structure for getdents(). Note that this structure is different from<br>
// the one in <dirent.h>, which is used by readdir().<br>
struct linux_dirent;<br>
<br>
+struct kernel_sigset_t {<br>
+ u8 sig[FIRST_32_SECOND_64(16, 8)];<br>
+};<br>
+<br>
+struct kernel_sigaction_t {<br>
+ union {<br>
+ void (*sigaction)(int signo, siginfo_t *info, void *ctx);<br>
+ void (*handler)(int signo);<br>
+ };<br>
+ unsigned long sa_flags;<br>
+ void (*sa_restorer)(void);<br>
+ kernel_sigset_t sa_mask;<br>
+};<br></blockquote><div><br></div><div>Hm... Consider moving this to sanitizer_platform_limits_posix.(h|cc).</div><div>I think that's where we collect definitions of OS-specific structures.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+<br>
// Syscall wrappers.<br>
uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);<br>
uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);<br>
uptr internal_sigaltstack(const struct sigaltstack* ss,<br>
struct sigaltstack* oss);<br>
+uptr internal_sigaction(int signum, const kernel_sigaction_t *act,<br>
+ kernel_sigaction_t *oldact);<br>
+uptr internal_sigprocmask(int how, kernel_sigset_t *set,<br>
+ kernel_sigset_t *oldset);<br>
+void internal_sigfillset(kernel_sigset_t *set);<br>
+void internal_sigdelset(kernel_sigset_t *set, int signum);<br>
+<br>
#ifdef __x86_64__<br>
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,<br>
int *parent_tidptr, void *newtls, int *child_tidptr);<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc?rev=192686&r1=192685&r2=192686&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc?rev=192686&r1=192685&r2=192686&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc Tue Oct 15 06:31:51 2013<br>
@@ -252,12 +252,12 @@ static int TracerThread(void* argument)<br>
// the mask we inherited from the caller thread.<br>
for (uptr signal_index = 0; signal_index < ARRAY_SIZE(kUnblockedSignals);<br>
signal_index++) {<br>
- struct sigaction new_sigaction;<br>
+ kernel_sigaction_t new_sigaction;<br>
internal_memset(&new_sigaction, 0, sizeof(new_sigaction));<br>
- new_sigaction.sa_sigaction = TracerThreadSignalHandler;<br>
+ new_sigaction.sigaction = TracerThreadSignalHandler;<br>
new_sigaction.sa_flags = SA_ONSTACK | SA_SIGINFO;<br>
- sigfillset(&new_sigaction.sa_mask);<br>
- sigaction(kUnblockedSignals[signal_index], &new_sigaction, NULL);<br>
+ internal_sigfillset(&new_sigaction.sa_mask);<br>
+ internal_sigaction(kUnblockedSignals[signal_index], &new_sigaction, NULL);<br>
}<br>
<br>
int exit_code = 0;<br>
@@ -307,9 +307,9 @@ NOINLINE static void WipeStack() {<br>
<br>
// We have a limitation on the stack frame size, so some stuff had to be moved<br>
// into globals.<br>
-static sigset_t blocked_sigset;<br>
-static sigset_t old_sigset;<br>
-static struct sigaction old_sigactions[ARRAY_SIZE(kUnblockedSignals)];<br>
+static kernel_sigset_t blocked_sigset;<br>
+static kernel_sigset_t old_sigset;<br>
+static kernel_sigaction_t old_sigactions[ARRAY_SIZE(kUnblockedSignals)];<br>
<br>
class StopTheWorldScope {<br>
public:<br>
@@ -323,21 +323,21 @@ class StopTheWorldScope {<br>
// We cannot allow user-defined handlers to run while the ThreadSuspender<br>
// thread is active, because they could conceivably call some libc functions<br>
// which modify errno (which is shared between the two threads).<br>
- sigfillset(&blocked_sigset);<br>
+ internal_sigfillset(&blocked_sigset);<br>
for (uptr signal_index = 0; signal_index < ARRAY_SIZE(kUnblockedSignals);<br>
signal_index++) {<br>
// Remove the signal from the set of blocked signals.<br>
- sigdelset(&blocked_sigset, kUnblockedSignals[signal_index]);<br>
+ internal_sigdelset(&blocked_sigset, kUnblockedSignals[signal_index]);<br>
// Install the default handler.<br>
- struct sigaction new_sigaction;<br>
+ kernel_sigaction_t new_sigaction;<br>
internal_memset(&new_sigaction, 0, sizeof(new_sigaction));<br>
- new_sigaction.sa_handler = SIG_DFL;<br>
- sigfillset(&new_sigaction.sa_mask);<br>
- sigaction(kUnblockedSignals[signal_index], &new_sigaction,<br>
+ new_sigaction.handler = SIG_DFL;<br>
+ internal_sigfillset(&new_sigaction.sa_mask);<br>
+ internal_sigaction(kUnblockedSignals[signal_index], &new_sigaction,<br>
&old_sigactions[signal_index]);<br>
}<br>
int sigprocmask_status =<br>
- sigprocmask(SIG_BLOCK, &blocked_sigset, &old_sigset);<br>
+ internal_sigprocmask(SIG_BLOCK, &blocked_sigset, &old_sigset);<br>
CHECK_EQ(sigprocmask_status, 0); // sigprocmask should never fail<br>
// Make this process dumpable. Processes that are not dumpable cannot be<br>
// attached to.<br>
@@ -355,10 +355,10 @@ class StopTheWorldScope {<br>
// Restore the signal handlers.<br>
for (uptr signal_index = 0; signal_index < ARRAY_SIZE(kUnblockedSignals);<br>
signal_index++) {<br>
- sigaction(kUnblockedSignals[signal_index],<br>
+ internal_sigaction(kUnblockedSignals[signal_index],<br>
&old_sigactions[signal_index], NULL);<br>
}<br>
- sigprocmask(SIG_SETMASK, &old_sigset, &old_sigset);<br>
+ internal_sigprocmask(SIG_SETMASK, &old_sigset, &old_sigset);<br>
}<br>
<br>
private:<br>
<br>
<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div>Alexey Samsonov, MSK</div>
</div></div>