<div dir="ltr"><br><div class="gmail_extra"><div class="gmail_quote">On Tue, Oct 15, 2013 at 4:09 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:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">the following lives in sanitizer_linux.h:<br>
<div class="im"><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>
<br>
</div>sigaction naturally fits here<br></blockquote><div><br></div><div>I disagree. I find it more convenient to have all re-definitions of POSIX structures in one place. Also,</div><div><span style="color:rgb(80,0,80)">sanitizer_platform_limits_</span><span style="color:rgb(80,0,80)">posix.cc has some useful compiler checks verifying that our re-definitions of</span><br>
</div><div><span style="color:rgb(80,0,80)">POSIX structs are actually correct.</span></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div class=""><div class="h5"><br>
<br>
<br>
On Tue, Oct 15, 2013 at 4:03 PM, Alexey Samsonov <<a href="mailto:samsonov@google.com">samsonov@google.com</a>> wrote:<br>
><br>
> On Tue, Oct 15, 2013 at 3:31 PM, Dmitry Vyukov <<a href="mailto:dvyukov@google.com">dvyukov@google.com</a>> wrote:<br>
>><br>
>> 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>
>><br>
>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc<br>
>><br>
>> Modified:<br>
>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc<br>
>> URL:<br>
>> <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>
>> ==============================================================================<br>
>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc<br>
>> (original)<br>
>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc<br>
>> 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>
>> \<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:<br>
>> <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>
>> ==============================================================================<br>
>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc (original)<br>
>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc Tue Oct 15<br>
>> 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:<br>
>> <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>
>> ==============================================================================<br>
>> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h (original)<br>
>> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h Tue Oct 15<br>
>> 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<br>
>> 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>
><br>
><br>
> Hm... Consider moving this to sanitizer_platform_limits_posix.(h|cc).<br>
> I think that's where we collect definitions of OS-specific structures.<br>
><br>
>><br>
>> +<br>
>> // Syscall wrappers.<br>
>> uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int<br>
>> count);<br>
>> uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr<br>
>> 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<br>
>> *arg,<br>
>> int *parent_tidptr, void *newtls, int *child_tidptr);<br>
>><br>
>> Modified:<br>
>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc<br>
>> URL:<br>
>> <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>
>> ==============================================================================<br>
>> ---<br>
>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc<br>
>> (original)<br>
>> +++<br>
>> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc<br>
>> 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 <<br>
>> 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,<br>
>> 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<br>
>> 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<br>
>> ThreadSuspender<br>
>> // thread is active, because they could conceivably call some libc<br>
>> 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 <<br>
>> 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,<br>
>> 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<br>
>> be<br>
>> // attached to.<br>
>> @@ -355,10 +355,10 @@ class StopTheWorldScope {<br>
>> // Restore the signal handlers.<br>
>> for (uptr signal_index = 0; signal_index <<br>
>> 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>
>> _______________________________________________<br>
>> llvm-commits mailing list<br>
>> <a href="mailto:llvm-commits@cs.uiuc.edu">llvm-commits@cs.uiuc.edu</a><br>
>> <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" target="_blank">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br>
><br>
><br>
><br>
><br>
> --<br>
> Alexey Samsonov, MSK<br>
</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div>Alexey Samsonov, MSK</div>
</div></div>