[compiler-rt] r192686 - tsan: implement internal syscall-based versions of sigaction/sigprocmask
Dmitry Vyukov
dvyukov at google.com
Tue Oct 15 06:01:59 PDT 2013
On Tue, Oct 15, 2013 at 4:21 PM, Alexey Samsonov <samsonov at google.com> wrote:
>
> On Tue, Oct 15, 2013 at 4:16 PM, Dmitry Vyukov <dvyukov at google.com> wrote:
>>
>> On Tue, Oct 15, 2013 at 4:13 PM, Alexey Samsonov <samsonov at google.com>
>> wrote:
>> >
>> > On Tue, Oct 15, 2013 at 4:09 PM, Dmitry Vyukov <dvyukov at google.com>
>> > wrote:
>> >>
>> >> the following lives in sanitizer_linux.h:
>> >>
>> >> uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int
>> >> count);
>> >> uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr
>> >> arg5);
>> >> uptr internal_sigaltstack(const struct sigaltstack* ss,
>> >> struct sigaltstack* oss);
>> >>
>> >> sigaction naturally fits here
>> >
>> >
>> > I disagree. I find it more convenient to have all re-definitions of
>> > POSIX
>> > structures in one place. Also,
>> > sanitizer_platform_limits_posix.cc has some useful compiler checks
>> > verifying
>> > that our re-definitions of
>> > POSIX structs are actually correct.
>>
>>
>> Do you mean only struct definititions?
>
> Yeah, I've meant kernel_sigset_t and kernel_sigaction_t struct definitions.
Done r192695.
>> What should I move to sanitizer_platform_limits_posix.cc?
>
> See CHECK_SIZE_AND_OFFSET macro in that file - can we apply them to our
> re-definitions of
> kernel_sigset_t and kernel_sigaction_t?
>>
>>
>>
>> >> On Tue, Oct 15, 2013 at 4:03 PM, Alexey Samsonov <samsonov at google.com>
>> >> wrote:
>> >> >
>> >> > On Tue, Oct 15, 2013 at 3:31 PM, Dmitry Vyukov <dvyukov at google.com>
>> >> > wrote:
>> >> >>
>> >> >> Author: dvyukov
>> >> >> Date: Tue Oct 15 06:31:51 2013
>> >> >> New Revision: 192686
>> >> >>
>> >> >> URL: http://llvm.org/viewvc/llvm-project?rev=192686&view=rev
>> >> >> Log:
>> >> >> tsan: implement internal syscall-based versions of
>> >> >> sigaction/sigprocmask
>> >> >> use them in stoptheworld
>> >> >> fixes applications that intercept sigaction/sigprocmask
>> >> >>
>> >> >>
>> >> >>
>> >> >> Modified:
>> >> >>
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h
>> >> >>
>> >> >>
>> >> >>
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
>> >> >>
>> >> >> Modified:
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc
>> >> >> URL:
>> >> >>
>> >> >>
>> >> >> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc?rev=192686&r1=192685&r2=192686&view=diff
>> >> >>
>> >> >>
>> >> >>
>> >> >> ==============================================================================
>> >> >> ---
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc
>> >> >> (original)
>> >> >> +++
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc
>> >> >> Tue Oct 15 06:31:51 2013
>> >> >> @@ -37,6 +37,7 @@
>> >> >> #if SANITIZER_LINUX
>> >> >>
>> >> >> #include "sanitizer_libc.h"
>> >> >> +#include "sanitizer_linux.h"
>> >> >>
>> >> >> #define PRE_SYSCALL(name)
>> >> >> \
>> >> >> SANITIZER_INTERFACE_ATTRIBUTE void
>> >> >> __sanitizer_syscall_pre_impl_##name
>> >> >> @@ -103,10 +104,6 @@ struct sanitizer_kernel_sockaddr {
>> >> >> char sa_data[14];
>> >> >> };
>> >> >>
>> >> >> -// Real sigset size is always passed as a syscall argument.
>> >> >> -// Declare it "void" to catch sizeof(kernel_sigset_t).
>> >> >> -typedef void kernel_sigset_t;
>> >> >> -
>> >> >> static void kernel_write_iovec(const __sanitizer_iovec *iovec,
>> >> >> SIZE_T iovlen, SIZE_T maxlen) {
>> >> >> for (SIZE_T i = 0; i < iovlen && maxlen; ++i) {
>> >> >>
>> >> >> Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
>> >> >> URL:
>> >> >>
>> >> >>
>> >> >> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc?rev=192686&r1=192685&r2=192686&view=diff
>> >> >>
>> >> >>
>> >> >>
>> >> >> ==============================================================================
>> >> >> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
>> >> >> (original)
>> >> >> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc Tue
>> >> >> Oct
>> >> >> 15
>> >> >> 06:31:51 2013
>> >> >> @@ -602,6 +602,31 @@ uptr internal_sigaltstack(const struct s
>> >> >> return internal_syscall(__NR_sigaltstack, ss, oss);
>> >> >> }
>> >> >>
>> >> >> +uptr internal_sigaction(int signum, const kernel_sigaction_t *act,
>> >> >> + struct kernel_sigaction_t *oldact) {
>> >> >> + return internal_syscall(__NR_rt_sigaction, signum, act, oldact,
>> >> >> + sizeof(kernel_sigset_t));
>> >> >> +}
>> >> >> +
>> >> >> +uptr internal_sigprocmask(int how, kernel_sigset_t *set,
>> >> >> + kernel_sigset_t *oldset) {
>> >> >> + return internal_syscall(__NR_rt_sigprocmask, (uptr)how,
>> >> >> &set->sig[0],
>> >> >> + &oldset->sig[0], sizeof(kernel_sigset_t));
>> >> >> +}
>> >> >> +
>> >> >> +void internal_sigfillset(kernel_sigset_t *set) {
>> >> >> + internal_memset(set, 0xff, sizeof(*set));
>> >> >> +}
>> >> >> +
>> >> >> +void internal_sigdelset(kernel_sigset_t *set, int signum) {
>> >> >> + signum -= 1;
>> >> >> + CHECK_GE(signum, 0);
>> >> >> + CHECK_LT(signum, sizeof(*set) * 8);
>> >> >> + const uptr idx = signum / (sizeof(set->sig[0]) * 8);
>> >> >> + const uptr bit = signum % (sizeof(set->sig[0]) * 8);
>> >> >> + set->sig[idx] &= ~(1 << bit);
>> >> >> +}
>> >> >> +
>> >> >> // ThreadLister implementation.
>> >> >> ThreadLister::ThreadLister(int pid)
>> >> >> : pid_(pid),
>> >> >>
>> >> >> Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h
>> >> >> URL:
>> >> >>
>> >> >>
>> >> >> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h?rev=192686&r1=192685&r2=192686&view=diff
>> >> >>
>> >> >>
>> >> >>
>> >> >> ==============================================================================
>> >> >> --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h
>> >> >> (original)
>> >> >> +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h Tue Oct
>> >> >> 15
>> >> >> 06:31:51 2013
>> >> >> @@ -20,17 +20,39 @@
>> >> >>
>> >> >> struct link_map; // Opaque type returned by dlopen().
>> >> >> struct sigaltstack;
>> >> >> +typedef struct siginfo siginfo_t;
>> >> >>
>> >> >> namespace __sanitizer {
>> >> >> // Dirent structure for getdents(). Note that this structure is
>> >> >> different
>> >> >> from
>> >> >> // the one in <dirent.h>, which is used by readdir().
>> >> >> struct linux_dirent;
>> >> >>
>> >> >> +struct kernel_sigset_t {
>> >> >> + u8 sig[FIRST_32_SECOND_64(16, 8)];
>> >> >> +};
>> >> >> +
>> >> >> +struct kernel_sigaction_t {
>> >> >> + union {
>> >> >> + void (*sigaction)(int signo, siginfo_t *info, void *ctx);
>> >> >> + void (*handler)(int signo);
>> >> >> + };
>> >> >> + unsigned long sa_flags;
>> >> >> + void (*sa_restorer)(void);
>> >> >> + kernel_sigset_t sa_mask;
>> >> >> +};
>> >> >
>> >> >
>> >> > Hm... Consider moving this to sanitizer_platform_limits_posix.(h|cc).
>> >> > I think that's where we collect definitions of OS-specific
>> >> > structures.
>> >> >
>> >> >>
>> >> >> +
>> >> >> // Syscall wrappers.
>> >> >> uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned
>> >> >> int
>> >> >> count);
>> >> >> uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4,
>> >> >> uptr
>> >> >> arg5);
>> >> >> uptr internal_sigaltstack(const struct sigaltstack* ss,
>> >> >> struct sigaltstack* oss);
>> >> >> +uptr internal_sigaction(int signum, const kernel_sigaction_t *act,
>> >> >> + kernel_sigaction_t *oldact);
>> >> >> +uptr internal_sigprocmask(int how, kernel_sigset_t *set,
>> >> >> + kernel_sigset_t *oldset);
>> >> >> +void internal_sigfillset(kernel_sigset_t *set);
>> >> >> +void internal_sigdelset(kernel_sigset_t *set, int signum);
>> >> >> +
>> >> >> #ifdef __x86_64__
>> >> >> uptr internal_clone(int (*fn)(void *), void *child_stack, int
>> >> >> flags,
>> >> >> void
>> >> >> *arg,
>> >> >> int *parent_tidptr, void *newtls, int
>> >> >> *child_tidptr);
>> >> >>
>> >> >> Modified:
>> >> >>
>> >> >>
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
>> >> >> URL:
>> >> >>
>> >> >>
>> >> >> 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
>> >> >>
>> >> >>
>> >> >>
>> >> >> ==============================================================================
>> >> >> ---
>> >> >>
>> >> >>
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
>> >> >> (original)
>> >> >> +++
>> >> >>
>> >> >>
>> >> >> compiler-rt/trunk/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
>> >> >> Tue Oct 15 06:31:51 2013
>> >> >> @@ -252,12 +252,12 @@ static int TracerThread(void* argument)
>> >> >> // the mask we inherited from the caller thread.
>> >> >> for (uptr signal_index = 0; signal_index <
>> >> >> ARRAY_SIZE(kUnblockedSignals);
>> >> >> signal_index++) {
>> >> >> - struct sigaction new_sigaction;
>> >> >> + kernel_sigaction_t new_sigaction;
>> >> >> internal_memset(&new_sigaction, 0, sizeof(new_sigaction));
>> >> >> - new_sigaction.sa_sigaction = TracerThreadSignalHandler;
>> >> >> + new_sigaction.sigaction = TracerThreadSignalHandler;
>> >> >> new_sigaction.sa_flags = SA_ONSTACK | SA_SIGINFO;
>> >> >> - sigfillset(&new_sigaction.sa_mask);
>> >> >> - sigaction(kUnblockedSignals[signal_index], &new_sigaction,
>> >> >> NULL);
>> >> >> + internal_sigfillset(&new_sigaction.sa_mask);
>> >> >> + internal_sigaction(kUnblockedSignals[signal_index],
>> >> >> &new_sigaction,
>> >> >> NULL);
>> >> >> }
>> >> >>
>> >> >> int exit_code = 0;
>> >> >> @@ -307,9 +307,9 @@ NOINLINE static void WipeStack() {
>> >> >>
>> >> >> // We have a limitation on the stack frame size, so some stuff had
>> >> >> to
>> >> >> be
>> >> >> moved
>> >> >> // into globals.
>> >> >> -static sigset_t blocked_sigset;
>> >> >> -static sigset_t old_sigset;
>> >> >> -static struct sigaction
>> >> >> old_sigactions[ARRAY_SIZE(kUnblockedSignals)];
>> >> >> +static kernel_sigset_t blocked_sigset;
>> >> >> +static kernel_sigset_t old_sigset;
>> >> >> +static kernel_sigaction_t
>> >> >> old_sigactions[ARRAY_SIZE(kUnblockedSignals)];
>> >> >>
>> >> >> class StopTheWorldScope {
>> >> >> public:
>> >> >> @@ -323,21 +323,21 @@ class StopTheWorldScope {
>> >> >> // We cannot allow user-defined handlers to run while the
>> >> >> ThreadSuspender
>> >> >> // thread is active, because they could conceivably call some
>> >> >> libc
>> >> >> functions
>> >> >> // which modify errno (which is shared between the two
>> >> >> threads).
>> >> >> - sigfillset(&blocked_sigset);
>> >> >> + internal_sigfillset(&blocked_sigset);
>> >> >> for (uptr signal_index = 0; signal_index <
>> >> >> ARRAY_SIZE(kUnblockedSignals);
>> >> >> signal_index++) {
>> >> >> // Remove the signal from the set of blocked signals.
>> >> >> - sigdelset(&blocked_sigset, kUnblockedSignals[signal_index]);
>> >> >> + internal_sigdelset(&blocked_sigset,
>> >> >> kUnblockedSignals[signal_index]);
>> >> >> // Install the default handler.
>> >> >> - struct sigaction new_sigaction;
>> >> >> + kernel_sigaction_t new_sigaction;
>> >> >> internal_memset(&new_sigaction, 0, sizeof(new_sigaction));
>> >> >> - new_sigaction.sa_handler = SIG_DFL;
>> >> >> - sigfillset(&new_sigaction.sa_mask);
>> >> >> - sigaction(kUnblockedSignals[signal_index], &new_sigaction,
>> >> >> + new_sigaction.handler = SIG_DFL;
>> >> >> + internal_sigfillset(&new_sigaction.sa_mask);
>> >> >> + internal_sigaction(kUnblockedSignals[signal_index],
>> >> >> &new_sigaction,
>> >> >> &old_sigactions[signal_index]);
>> >> >> }
>> >> >> int sigprocmask_status =
>> >> >> - sigprocmask(SIG_BLOCK, &blocked_sigset, &old_sigset);
>> >> >> + internal_sigprocmask(SIG_BLOCK, &blocked_sigset,
>> >> >> &old_sigset);
>> >> >> CHECK_EQ(sigprocmask_status, 0); // sigprocmask should never
>> >> >> fail
>> >> >> // Make this process dumpable. Processes that are not dumpable
>> >> >> cannot
>> >> >> be
>> >> >> // attached to.
>> >> >> @@ -355,10 +355,10 @@ class StopTheWorldScope {
>> >> >> // Restore the signal handlers.
>> >> >> for (uptr signal_index = 0; signal_index <
>> >> >> ARRAY_SIZE(kUnblockedSignals);
>> >> >> signal_index++) {
>> >> >> - sigaction(kUnblockedSignals[signal_index],
>> >> >> + internal_sigaction(kUnblockedSignals[signal_index],
>> >> >> &old_sigactions[signal_index], NULL);
>> >> >> }
>> >> >> - sigprocmask(SIG_SETMASK, &old_sigset, &old_sigset);
>> >> >> + internal_sigprocmask(SIG_SETMASK, &old_sigset, &old_sigset);
>> >> >> }
>> >> >>
>> >> >> private:
>> >> >>
>> >> >>
>> >> >> _______________________________________________
>> >> >> llvm-commits mailing list
>> >> >> llvm-commits at cs.uiuc.edu
>> >> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Alexey Samsonov, MSK
>> >
>> >
>> >
>> >
>> > --
>> > Alexey Samsonov, MSK
>
>
>
>
> --
> Alexey Samsonov, MSK
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