[compiler-rt] r273260 - [asan] add primitives that allow coroutine implementations
Mike Aizatsky via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 22 08:30:55 PDT 2016
Dmitry,
This still fails:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/24385/steps/run%20tests/logs/stdio
On Tue, Jun 21, 2016 at 1:40 PM Dmitry Vyukov <dvyukov at google.com> wrote:
> Philippe prepared r273288 to fix it.
>
> On Tue, Jun 21, 2016 at 8:28 PM, Mike Aizatsky <aizatsky at google.com>
> wrote:
> > Dmitry,
> >
> > I think this breaks sanitizer-windows build:
> >
> >
> http://lab.llvm.org:8011/builders/sanitizer-windows/builds/24305/steps/run%20tests/logs/stdio
> >
> > First build with the problem:
> > http://lab.llvm.org:8011/builders/sanitizer-windows/builds/24286
> >
> >
> > On Tue, Jun 21, 2016 at 5:36 AM Dmitry Vyukov via llvm-commits
> > <llvm-commits at lists.llvm.org> wrote:
> >>
> >> Author: dvyukov
> >> Date: Tue Jun 21 07:29:18 2016
> >> New Revision: 273260
> >>
> >> URL: http://llvm.org/viewvc/llvm-project?rev=273260&view=rev
> >> Log:
> >> [asan] add primitives that allow coroutine implementations
> >>
> >> This patch adds the __sanitizer_start_switch_fiber and
> >> __sanitizer_finish_switch_fiber methods inspired from what can be found
> >> here
> >>
> >>
> https://github.com/facebook/folly/commit/2ea64dd24946cbc9f3f4ac3f6c6b98a486c56e73
> >> .
> >>
> >> These methods are needed when the compiled software needs to implement
> >> coroutines, fibers or the like. Without a way to annotate them, when the
> >> program
> >> jumps to a stack that is not the thread stack, __asan_handle_no_return
> >> shows a
> >> warning about that, and the fake stack mechanism may free fake frames
> that
> >> are
> >> still in use.
> >>
> >> Author: blastrock (Philippe Daouadi)
> >> Reviewed in http://reviews.llvm.org/D20913
> >>
> >>
> >> Added:
> >>
> compiler-rt/trunk/test/asan/TestCases/Linux/swapcontext_annotation.cc
> >> Modified:
> >> compiler-rt/trunk/include/sanitizer/common_interface_defs.h
> >> compiler-rt/trunk/lib/asan/asan_thread.cc
> >> compiler-rt/trunk/lib/asan/asan_thread.h
> >>
> >> Modified: compiler-rt/trunk/include/sanitizer/common_interface_defs.h
> >> URL:
> >>
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/sanitizer/common_interface_defs.h?rev=273260&r1=273259&r2=273260&view=diff
> >>
> >>
> ==============================================================================
> >> --- compiler-rt/trunk/include/sanitizer/common_interface_defs.h
> (original)
> >> +++ compiler-rt/trunk/include/sanitizer/common_interface_defs.h Tue Jun
> 21
> >> 07:29:18 2016
> >> @@ -139,6 +139,26 @@ extern "C" {
> >> // `top_percent` should be between 1 and 100.
> >> // Experimental feature currently available only with asan on
> >> Linux/x86_64.
> >> void __sanitizer_print_memory_profile(size_t top_percent);
> >> +
> >> + // Fiber annotation interface.
> >> + // Before switching to a different stack, one must call
> >> + // __sanitizer_start_switch_fiber with a pointer to the bottom of the
> >> + // destination stack and its size. When code starts running on the
> new
> >> stack,
> >> + // it must call __sanitizer_finish_switch_fiber to finalize the
> switch.
> >> + // The start_switch function takes a void** to store the current fake
> >> stack if
> >> + // there is one (it is needed when detect_stack_use_after_return is
> >> enabled).
> >> + // When restoring a stack, this pointer must be given to the
> >> finish_switch
> >> + // function. In most cases, this void* can be stored on the stack
> just
> >> before
> >> + // switching. When leaving a fiber definitely, null must be passed
> as
> >> first
> >> + // argument to the start_switch function so that the fake stack is
> >> destroyed.
> >> + // If you do not want support for stack use-after-return detection,
> you
> >> can
> >> + // always pass null to these two functions.
> >> + // Note that the fake stack mechanism is disabled during fiber
> switch,
> >> so if a
> >> + // signal callback runs during the switch, it will not benefit from
> the
> >> stack
> >> + // use-after-return detection.
> >> + void __sanitizer_start_switch_fiber(void **fake_stack_save,
> >> + const void *bottom, size_t size);
> >> + void __sanitizer_finish_switch_fiber(void *fake_stack_save);
> >> #ifdef __cplusplus
> >> } // extern "C"
> >> #endif
> >>
> >> Modified: compiler-rt/trunk/lib/asan/asan_thread.cc
> >> URL:
> >>
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_thread.cc?rev=273260&r1=273259&r2=273260&view=diff
> >>
> >>
> ==============================================================================
> >> --- compiler-rt/trunk/lib/asan/asan_thread.cc (original)
> >> +++ compiler-rt/trunk/lib/asan/asan_thread.cc Tue Jun 21 07:29:18 2016
> >> @@ -120,6 +120,71 @@ void AsanThread::Destroy() {
> >> DTLS_Destroy();
> >> }
> >>
> >> +void AsanThread::StartSwitchFiber(FakeStack **fake_stack_save, uptr
> >> bottom,
> >> + uptr size) {
> >> + if (atomic_load(&stack_switching_, memory_order_relaxed)) {
> >> + Report("ERROR: starting fiber switch while in fiber switch\n");
> >> + Die();
> >> + }
> >> +
> >> + next_stack_bottom_ = bottom;
> >> + next_stack_top_ = bottom + size;
> >> + atomic_store(&stack_switching_, 1, memory_order_release);
> >> +
> >> + FakeStack *current_fake_stack = fake_stack_;
> >> + if (fake_stack_save)
> >> + *fake_stack_save = fake_stack_;
> >> + fake_stack_ = nullptr;
> >> + SetTLSFakeStack(nullptr);
> >> + // if fake_stack_save is null, the fiber will die, delete the
> fakestack
> >> + if (!fake_stack_save && current_fake_stack)
> >> + current_fake_stack->Destroy(this->tid());
> >> +}
> >> +
> >> +void AsanThread::FinishSwitchFiber(FakeStack *fake_stack_save) {
> >> + if (!atomic_load(&stack_switching_, memory_order_relaxed)) {
> >> + Report("ERROR: finishing a fiber switch that has not started\n");
> >> + Die();
> >> + }
> >> +
> >> + if (fake_stack_save) {
> >> + SetTLSFakeStack(fake_stack_save);
> >> + fake_stack_ = fake_stack_save;
> >> + }
> >> +
> >> + stack_bottom_ = next_stack_bottom_;
> >> + stack_top_ = next_stack_top_;
> >> + atomic_store(&stack_switching_, 0, memory_order_release);
> >> + next_stack_top_ = 0;
> >> + next_stack_bottom_ = 0;
> >> +}
> >> +
> >> +inline AsanThread::StackBounds AsanThread::GetStackBounds() const {
> >> + if (!atomic_load(&stack_switching_, memory_order_acquire))
> >> + return StackBounds{stack_bottom_, stack_top_}; // NOLINT
> >> + char local;
> >> + const uptr cur_stack = (uptr)&local;
> >> + // Note: need to check next stack first, because FinishSwitchFiber
> >> + // may be in process of overwriting stack_top_/bottom_. But in such
> >> case
> >> + // we are already on the next stack.
> >> + if (cur_stack >= next_stack_bottom_ && cur_stack < next_stack_top_)
> >> + return StackBounds{next_stack_bottom_, next_stack_top_}; // NOLINT
> >> + return StackBounds{stack_bottom_, stack_top_}; // NOLINT
> >> +}
> >> +
> >> +uptr AsanThread::stack_top() {
> >> + return GetStackBounds().top;
> >> +}
> >> +
> >> +uptr AsanThread::stack_bottom() {
> >> + return GetStackBounds().bottom;
> >> +}
> >> +
> >> +uptr AsanThread::stack_size() {
> >> + const auto bounds = GetStackBounds();
> >> + return bounds.top - bounds.bottom;
> >> +}
> >> +
> >> // We want to create the FakeStack lazyly on the first use, but not
> >> eralier
> >> // than the stack size is known and the procedure has to be
> async-signal
> >> safe.
> >> FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
> >> @@ -150,6 +215,8 @@ FakeStack *AsanThread::AsyncSignalSafeLa
> >> }
> >>
> >> void AsanThread::Init() {
> >> + next_stack_top_ = next_stack_bottom_ = 0;
> >> + atomic_store(&stack_switching_, false, memory_order_release);
> >> fake_stack_ = nullptr; // Will be initialized lazily if needed.
> >> CHECK_EQ(this->stack_size(), 0U);
> >> SetThreadStackAndTls();
> >> @@ -195,9 +262,10 @@ thread_return_t AsanThread::ThreadStart(
> >>
> >> void AsanThread::SetThreadStackAndTls() {
> >> uptr tls_size = 0;
> >> - GetThreadStackAndTls(tid() == 0, &stack_bottom_, &stack_size_,
> >> &tls_begin_,
> >> - &tls_size);
> >> - stack_top_ = stack_bottom_ + stack_size_;
> >> + uptr stack_size = 0;
> >> + GetThreadStackAndTls(tid() == 0, const_cast<uptr *>(&stack_bottom_),
> >> + const_cast<uptr *>(&stack_size), &tls_begin_,
> >> &tls_size);
> >> + stack_top_ = stack_bottom_ + stack_size;
> >> tls_end_ = tls_begin_ + tls_size;
> >> dtls_ = DTLS_Get();
> >>
> >> @@ -250,6 +318,11 @@ bool AsanThread::GetStackFrameAccessByAd
> >> return true;
> >> }
> >>
> >> +bool AsanThread::AddrIsInStack(uptr addr) {
> >> + const auto bounds = GetStackBounds();
> >> + return addr >= bounds.bottom && addr < bounds.top;
> >> +}
> >> +
> >> static bool ThreadStackContainsAddress(ThreadContextBase *tctx_base,
> >> void *addr) {
> >> AsanThreadContext *tctx = static_cast<AsanThreadContext*>(tctx_base);
> >> @@ -357,3 +430,29 @@ void EnsureMainThreadIDIsCorrect() {
> >> __asan::EnsureMainThreadIDIsCorrect();
> >> }
> >> } // namespace __lsan
> >> +
> >> +// ---------------------- Interface ---------------- {{{1
> >> +using namespace __asan; // NOLINT
> >> +
> >> +extern "C" {
> >> +SANITIZER_INTERFACE_ATTRIBUTE
> >> +void __sanitizer_start_switch_fiber(void **fakestacksave, const void
> >> *bottom,
> >> + uptr size) {
> >> + AsanThread *t = GetCurrentThread();
> >> + if (!t) {
> >> + VReport(1, "__asan_start_switch_fiber called from unknown
> thread\n");
> >> + return;
> >> + }
> >> + t->StartSwitchFiber((FakeStack**)fakestacksave, (uptr)bottom, size);
> >> +}
> >> +
> >> +SANITIZER_INTERFACE_ATTRIBUTE
> >> +void __sanitizer_finish_switch_fiber(void* fakestack) {
> >> + AsanThread *t = GetCurrentThread();
> >> + if (!t) {
> >> + VReport(1, "__asan_finish_switch_fiber called from unknown
> >> thread\n");
> >> + return;
> >> + }
> >> + t->FinishSwitchFiber((FakeStack*)fakestack);
> >> +}
> >> +}
> >>
> >> Modified: compiler-rt/trunk/lib/asan/asan_thread.h
> >> URL:
> >>
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_thread.h?rev=273260&r1=273259&r2=273260&view=diff
> >>
> >>
> ==============================================================================
> >> --- compiler-rt/trunk/lib/asan/asan_thread.h (original)
> >> +++ compiler-rt/trunk/lib/asan/asan_thread.h Tue Jun 21 07:29:18 2016
> >> @@ -66,9 +66,9 @@ class AsanThread {
> >> thread_return_t ThreadStart(uptr os_id,
> >> atomic_uintptr_t
> >> *signal_thread_is_registered);
> >>
> >> - uptr stack_top() { return stack_top_; }
> >> - uptr stack_bottom() { return stack_bottom_; }
> >> - uptr stack_size() { return stack_size_; }
> >> + uptr stack_top();
> >> + uptr stack_bottom();
> >> + uptr stack_size();
> >> uptr tls_begin() { return tls_begin_; }
> >> uptr tls_end() { return tls_end_; }
> >> DTLS *dtls() { return dtls_; }
> >> @@ -83,9 +83,7 @@ class AsanThread {
> >> };
> >> bool GetStackFrameAccessByAddr(uptr addr, StackFrameAccess *access);
> >>
> >> - bool AddrIsInStack(uptr addr) {
> >> - return addr >= stack_bottom_ && addr < stack_top_;
> >> - }
> >> + bool AddrIsInStack(uptr addr);
> >>
> >> void DeleteFakeStack(int tid) {
> >> if (!fake_stack_) return;
> >> @@ -95,13 +93,19 @@ class AsanThread {
> >> t->Destroy(tid);
> >> }
> >>
> >> + void StartSwitchFiber(FakeStack **fake_stack_save, uptr bottom, uptr
> >> size);
> >> + void FinishSwitchFiber(FakeStack *fake_stack_save);
> >> +
> >> bool has_fake_stack() {
> >> - return (reinterpret_cast<uptr>(fake_stack_) > 1);
> >> + return !atomic_load(&stack_switching_, memory_order_relaxed) &&
> >> + (reinterpret_cast<uptr>(fake_stack_) > 1);
> >> }
> >>
> >> FakeStack *fake_stack() {
> >> if (!__asan_option_detect_stack_use_after_return)
> >> return nullptr;
> >> + if (atomic_load(&stack_switching_, memory_order_relaxed))
> >> + return nullptr;
> >> if (!has_fake_stack())
> >> return AsyncSignalSafeLazyInitFakeStack();
> >> return fake_stack_;
> >> @@ -127,14 +131,24 @@ class AsanThread {
> >> void ClearShadowForThreadStackAndTLS();
> >> FakeStack *AsyncSignalSafeLazyInitFakeStack();
> >>
> >> + struct StackBounds {
> >> + uptr bottom;
> >> + uptr top;
> >> + };
> >> + StackBounds GetStackBounds() const;
> >> +
> >> AsanThreadContext *context_;
> >> thread_callback_t start_routine_;
> >> void *arg_;
> >> +
> >> uptr stack_top_;
> >> uptr stack_bottom_;
> >> - // stack_size_ == stack_top_ - stack_bottom_;
> >> - // It needs to be set in a async-signal-safe manner.
> >> - uptr stack_size_;
> >> + // these variables are used when the thread is about to switch stack
> >> + uptr next_stack_top_;
> >> + uptr next_stack_bottom_;
> >> + // true if switching is in progress
> >> + atomic_uint8_t stack_switching_;
> >> +
> >> uptr tls_begin_;
> >> uptr tls_end_;
> >> DTLS *dtls_;
> >>
> >> Added:
> >> compiler-rt/trunk/test/asan/TestCases/Linux/swapcontext_annotation.cc
> >> URL:
> >>
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Linux/swapcontext_annotation.cc?rev=273260&view=auto
> >>
> >>
> ==============================================================================
> >> ---
> compiler-rt/trunk/test/asan/TestCases/Linux/swapcontext_annotation.cc
> >> (added)
> >> +++
> compiler-rt/trunk/test/asan/TestCases/Linux/swapcontext_annotation.cc
> >> Tue Jun 21 07:29:18 2016
> >> @@ -0,0 +1,178 @@
> >> +// Check that ASan plays well with annotated makecontext/swapcontext.
> >> +
> >> +// RUN: %clangxx_asan -lpthread -O0 %s -o %t && %run %t 2>&1 |
> FileCheck
> >> %s
> >> +// RUN: %clangxx_asan -lpthread -O1 %s -o %t && %run %t 2>&1 |
> FileCheck
> >> %s
> >> +// RUN: %clangxx_asan -lpthread -O2 %s -o %t && %run %t 2>&1 |
> FileCheck
> >> %s
> >> +// RUN: %clangxx_asan -lpthread -O3 %s -o %t && %run %t 2>&1 |
> FileCheck
> >> %s
> >> +//
> >> +// This test is too subtle to try on non-x86 arch for now.
> >> +// REQUIRES: x86_64-supported-target,i386-supported-target
> >> +
> >> +#include <pthread.h>
> >> +#include <setjmp.h>
> >> +#include <stdio.h>
> >> +#include <sys/time.h>
> >> +#include <ucontext.h>
> >> +#include <unistd.h>
> >> +
> >> +#include <sanitizer/common_interface_defs.h>
> >> +
> >> +ucontext_t orig_context;
> >> +ucontext_t child_context;
> >> +ucontext_t next_child_context;
> >> +
> >> +char *next_child_stack;
> >> +
> >> +const int kStackSize = 1 << 20;
> >> +
> >> +void *main_thread_stack;
> >> +size_t main_thread_stacksize;
> >> +
> >> +__attribute__((noinline, noreturn)) void LongJump(jmp_buf env) {
> >> + longjmp(env, 1);
> >> + _exit(1);
> >> +}
> >> +
> >> +// Simulate __asan_handle_no_return().
> >> +__attribute__((noinline)) void CallNoReturn() {
> >> + jmp_buf env;
> >> + if (setjmp(env) != 0) return;
> >> +
> >> + LongJump(env);
> >> + _exit(1);
> >> +}
> >> +
> >> +void NextChild() {
> >> + CallNoReturn();
> >> + __sanitizer_finish_switch_fiber();
> >> +
> >> + char x[32] = {0}; // Stack gets poisoned.
> >> + printf("NextChild: %p\n", x);
> >> +
> >> + CallNoReturn();
> >> +
> >> + __sanitizer_start_switch_fiber(main_thread_stack,
> >> main_thread_stacksize);
> >> + CallNoReturn();
> >> + if (swapcontext(&next_child_context, &orig_context) < 0) {
> >> + perror("swapcontext");
> >> + _exit(1);
> >> + }
> >> +}
> >> +
> >> +void Child(int mode) {
> >> + CallNoReturn();
> >> + __sanitizer_finish_switch_fiber();
> >> + char x[32] = {0}; // Stack gets poisoned.
> >> + printf("Child: %p\n", x);
> >> + CallNoReturn();
> >> + // (a) Do nothing, just return to parent function.
> >> + // (b) Jump into the original function. Stack remains poisoned unless
> >> we do
> >> + // something.
> >> + // (c) Jump to another function which will then jump back to the main
> >> function
> >> + if (mode == 0) {
> >> + __sanitizer_start_switch_fiber(main_thread_stack,
> >> main_thread_stacksize);
> >> + CallNoReturn();
> >> + } else if (mode == 1) {
> >> + __sanitizer_start_switch_fiber(main_thread_stack,
> >> main_thread_stacksize);
> >> + CallNoReturn();
> >> + if (swapcontext(&child_context, &orig_context) < 0) {
> >> + perror("swapcontext");
> >> + _exit(1);
> >> + }
> >> + } else if (mode == 2) {
> >> + getcontext(&next_child_context);
> >> + next_child_context.uc_stack.ss_sp = next_child_stack;
> >> + next_child_context.uc_stack.ss_size = kStackSize / 2;
> >> + makecontext(&next_child_context, (void (*)())NextChild, 0);
> >> + __sanitizer_start_switch_fiber(next_child_context.uc_stack.ss_sp,
> >> +
> next_child_context.uc_stack.ss_size);
> >> + CallNoReturn();
> >> + if (swapcontext(&child_context, &next_child_context) < 0) {
> >> + perror("swapcontext");
> >> + _exit(1);
> >> + }
> >> + }
> >> +}
> >> +
> >> +int Run(int arg, int mode, char *child_stack) {
> >> + printf("Child stack: %p\n", child_stack);
> >> + // Setup child context.
> >> + getcontext(&child_context);
> >> + child_context.uc_stack.ss_sp = child_stack;
> >> + child_context.uc_stack.ss_size = kStackSize / 2;
> >> + if (mode == 0) {
> >> + child_context.uc_link = &orig_context;
> >> + }
> >> + makecontext(&child_context, (void (*)())Child, 1, mode);
> >> + CallNoReturn();
> >> + __sanitizer_start_switch_fiber(child_context.uc_stack.ss_sp,
> >> + child_context.uc_stack.ss_size);
> >> + CallNoReturn();
> >> + if (swapcontext(&orig_context, &child_context) < 0) {
> >> + perror("swapcontext");
> >> + _exit(1);
> >> + }
> >> + CallNoReturn();
> >> + __sanitizer_finish_switch_fiber();
> >> + CallNoReturn();
> >> +
> >> + // Touch childs's stack to make sure it's unpoisoned.
> >> + for (int i = 0; i < kStackSize; i++) {
> >> + child_stack[i] = i;
> >> + }
> >> + return child_stack[arg];
> >> +}
> >> +
> >> +void handler(int sig) { CallNoReturn(); }
> >> +
> >> +void InitStackBounds() {
> >> + pthread_attr_t attr;
> >> + pthread_attr_init(&attr);
> >> + pthread_getattr_np(pthread_self(), &attr);
> >> + pthread_attr_getstack(&attr, &main_thread_stack,
> >> &main_thread_stacksize);
> >> + pthread_attr_destroy(&attr);
> >> +}
> >> +
> >> +int main(int argc, char **argv) {
> >> + InitStackBounds();
> >> +
> >> + // set up a signal that will spam and trigger __asan_handle_no_return
> >> at
> >> + // tricky moments
> >> + struct sigaction act = {};
> >> + act.sa_handler = &handler;
> >> + if (sigaction(SIGPROF, &act, 0)) {
> >> + perror("sigaction");
> >> + _exit(1);
> >> + }
> >> +
> >> + itimerval t;
> >> + t.it_interval.tv_sec = 0;
> >> + t.it_interval.tv_usec = 10;
> >> + t.it_value = t.it_interval;
> >> + if (setitimer(ITIMER_PROF, &t, 0)) {
> >> + perror("setitimer");
> >> + _exit(1);
> >> + }
> >> +
> >> + char *heap = new char[kStackSize + 1];
> >> + next_child_stack = new char[kStackSize + 1];
> >> + char stack[kStackSize + 1];
> >> + // CHECK: WARNING: ASan doesn't fully support makecontext/swapcontext
> >> + int ret = 0;
> >> + // CHECK-NOT: ASan is ignoring requested __asan_handle_no_return
> >> + for (unsigned int i = 0; i < 30; ++i) {
> >> + ret += Run(argc - 1, 0, stack);
> >> + ret += Run(argc - 1, 1, stack);
> >> + ret += Run(argc - 1, 2, stack);
> >> + ret += Run(argc - 1, 0, heap);
> >> + ret += Run(argc - 1, 1, heap);
> >> + ret += Run(argc - 1, 2, heap);
> >> + }
> >> + // CHECK: Test passed
> >> + printf("Test passed\n");
> >> +
> >> + delete[] heap;
> >> + delete[] next_child_stack;
> >> +
> >> + return ret;
> >> +}
> >>
> >>
> >> _______________________________________________
> >> llvm-commits mailing list
> >> llvm-commits at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
> >
> > --
> > Mike
> > Sent from phone
>
--
Mike
Sent from phone
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160622/33dfe56e/attachment-0001.html>
More information about the llvm-commits
mailing list