This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGa345419ee030: [lldb] [Process] Watch for fork/vfork
notifications (authored by mgorny).
Herald added a project: LLDB.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D98822/new/
https://reviews.llvm.org/D98822
Files:
lldb/include/lldb/Host/linux/Host.h
lldb/source/Host/linux/Host.cpp
lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.cpp
lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.h
lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD.h
lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.cpp
lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.h
lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.cpp
lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.h
lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
lldb/test/API/functionalities/gdb_remote_client/TestMultiprocess.py
lldb/test/Shell/Subprocess/Inputs/fork.cpp
lldb/test/Shell/Subprocess/clone-follow-parent-wp.test
lldb/test/Shell/Subprocess/clone-follow-parent.test
lldb/test/Shell/Subprocess/fork-follow-parent-wp.test
lldb/test/Shell/Subprocess/fork-follow-parent.test
lldb/test/Shell/Subprocess/vfork-follow-parent-wp.test
lldb/test/Shell/Subprocess/vfork-follow-parent.test
Index: lldb/test/Shell/Subprocess/vfork-follow-parent.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/vfork-follow-parent.test
@@ -0,0 +1,11 @@
+# REQUIRES: native
+# UNSUPPORTED: system-windows
+# RUN: %clangxx_host %p/Inputs/fork.cpp -DTEST_FORK=vfork -o %t
+# RUN: %lldb -b -s %s %t | FileCheck %s
+b parent_func
+process launch
+# CHECK-NOT: function run in parent
+# CHECK: stop reason = breakpoint
+continue
+# CHECK: function run in parent
+# CHECK: child exited: 0
Index: lldb/test/Shell/Subprocess/vfork-follow-parent-wp.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/vfork-follow-parent-wp.test
@@ -0,0 +1,13 @@
+# REQUIRES: native && dbregs-set
+# UNSUPPORTED: system-windows
+# RUN: %clangxx_host -g %p/Inputs/fork.cpp -DTEST_FORK=vfork -o %t
+# RUN: %lldb -b -s %s %t | FileCheck %s
+process launch -s
+watchpoint set variable -w write g_val
+# CHECK: Watchpoint created:
+continue
+# CHECK-NOT: function run in parent
+# CHECK: stop reason = watchpoint
+continue
+# CHECK: function run in parent
+# CHECK: child exited: 0
Index: lldb/test/Shell/Subprocess/fork-follow-parent.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/fork-follow-parent.test
@@ -0,0 +1,11 @@
+# REQUIRES: native
+# UNSUPPORTED: system-windows
+# RUN: %clangxx_host %p/Inputs/fork.cpp -DTEST_FORK=fork -o %t
+# RUN: %lldb -b -s %s %t | FileCheck %s
+b parent_func
+process launch
+# CHECK-NOT: function run in parent
+# CHECK: stop reason = breakpoint
+continue
+# CHECK: function run in parent
+# CHECK: child exited: 0
Index: lldb/test/Shell/Subprocess/fork-follow-parent-wp.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/fork-follow-parent-wp.test
@@ -0,0 +1,13 @@
+# REQUIRES: native && dbregs-set
+# UNSUPPORTED: system-windows
+# RUN: %clangxx_host -g %p/Inputs/fork.cpp -DTEST_FORK=fork -o %t
+# RUN: %lldb -b -s %s %t | FileCheck %s
+process launch -s
+watchpoint set variable -w write g_val
+# CHECK: Watchpoint created:
+continue
+# CHECK-NOT: function run in parent
+# CHECK: stop reason = watchpoint
+continue
+# CHECK: function run in parent
+# CHECK: child exited: 0
Index: lldb/test/Shell/Subprocess/clone-follow-parent.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/clone-follow-parent.test
@@ -0,0 +1,10 @@
+# REQUIRES: native && (system-linux || system-netbsd)
+# RUN: %clangxx_host %p/Inputs/fork.cpp -DTEST_CLONE -o %t
+# RUN: %lldb -b -s %s %t | FileCheck %s
+b parent_func
+process launch
+# CHECK-NOT: function run in parent
+# CHECK: stop reason = breakpoint
+continue
+# CHECK: function run in parent
+# CHECK: child exited: 0
Index: lldb/test/Shell/Subprocess/clone-follow-parent-wp.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/clone-follow-parent-wp.test
@@ -0,0 +1,12 @@
+# REQUIRES: native && (system-linux || system-netbsd) && dbregs-set
+# RUN: %clangxx_host -g %p/Inputs/fork.cpp -DTEST_CLONE -o %t
+# RUN: %lldb -b -s %s %t | FileCheck %s
+process launch -s
+watchpoint set variable -w write g_val
+# CHECK: Watchpoint created:
+continue
+# CHECK-NOT: function run in parent
+# CHECK: stop reason = watchpoint
+continue
+# CHECK: function run in parent
+# CHECK: child exited: 0
Index: lldb/test/Shell/Subprocess/Inputs/fork.cpp
===================================================================
--- /dev/null
+++ lldb/test/Shell/Subprocess/Inputs/fork.cpp
@@ -0,0 +1,50 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <assert.h>
+#if defined(TEST_CLONE)
+#include <sched.h>
+#endif
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int g_val = 0;
+
+void parent_func() {
+ g_val = 1;
+ printf("function run in parent\n");
+}
+
+int child_func(void *unused) {
+ // we need to avoid memory modifications for vfork(), yet we want
+ // to be able to test watchpoints, so do the next best thing
+ // and restore the original value
+ g_val = 2;
+ g_val = 0;
+ return 0;
+}
+
+int main() {
+ alignas(uintmax_t) char stack[4096];
+
+#if defined(TEST_CLONE)
+ pid_t pid = clone(child_func, &stack[sizeof(stack)], 0, NULL);
+#elif defined(TEST_FORK)
+ pid_t pid = TEST_FORK();
+ if (pid == 0)
+ _exit(child_func(NULL));
+#endif
+ assert(pid != -1);
+
+ parent_func();
+ int status, wait_flags = 0;
+#if defined(TEST_CLONE)
+ wait_flags = __WALL;
+#endif
+ pid_t waited = waitpid(pid, &status, wait_flags);
+ assert(waited == pid);
+ assert(WIFEXITED(status));
+ printf("child exited: %d\n", WEXITSTATUS(status));
+
+ return 0;
+}
Index: lldb/test/API/functionalities/gdb_remote_client/TestMultiprocess.py
===================================================================
--- lldb/test/API/functionalities/gdb_remote_client/TestMultiprocess.py
+++ lldb/test/API/functionalities/gdb_remote_client/TestMultiprocess.py
@@ -1,6 +1,5 @@
from __future__ import print_function
import lldb
-import unittest
from lldbsuite.test.lldbtest import *
from lldbsuite.test.decorators import *
from gdbclientutils import *
Index: lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
===================================================================
--- lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
+++ lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
@@ -106,6 +106,7 @@
void MonitorSIGSTOP(lldb::pid_t pid);
void MonitorSIGTRAP(lldb::pid_t pid);
void MonitorSignal(lldb::pid_t pid, int signal);
+ void MonitorClone(::pid_t child_pid);
Status PopulateMemoryRegionCache();
void SigchldHandler();
Index: lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
===================================================================
--- lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
+++ lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
@@ -256,6 +256,24 @@
SetState(StateType::eStateStopped, true);
return;
}
+ case TRAP_CHLD: {
+ ptrace_state_t pst;
+ Status error = PtraceWrapper(PT_GET_PROCESS_STATE, pid, &pst, sizeof(pst));
+ if (error.Fail()) {
+ SetState(StateType::eStateInvalid);
+ return;
+ }
+
+ if (pst.pe_report_event == PTRACE_VFORK_DONE) {
+ Status error =
+ PtraceWrapper(PT_CONTINUE, pid, reinterpret_cast<void *>(1), 0);
+ if (error.Fail())
+ SetState(StateType::eStateInvalid);
+ return;
+ } else
+ MonitorClone(pst.pe_other_pid);
+ return;
+ }
case TRAP_LWP: {
ptrace_state_t pst;
Status error = PtraceWrapper(PT_GET_PROCESS_STATE, pid, &pst, sizeof(pst));
@@ -510,7 +528,7 @@
if (GetID() == LLDB_INVALID_PROCESS_ID)
return error;
- return PtraceWrapper(PT_DETACH, GetID());
+ return PtraceWrapper(PT_DETACH, GetID(), reinterpret_cast<void *>(1));
}
Status NativeProcessNetBSD::Signal(int signo) {
@@ -738,17 +756,17 @@
void NativeProcessNetBSD::SigchldHandler() {
Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
- // Process all pending waitpid notifications.
int status;
::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, waitpid, GetID(), &status,
WALLSIG | WNOHANG);
if (wait_pid == 0)
- return; // We are done.
+ return;
if (wait_pid == -1) {
Status error(errno, eErrorTypePOSIX);
LLDB_LOG(log, "waitpid ({0}, &status, _) failed: {1}", GetID(), error);
+ return;
}
WaitStatus wait_status = WaitStatus::Decode(status);
@@ -936,8 +954,9 @@
PtraceWrapper(PT_GET_EVENT_MASK, GetID(), &events, sizeof(events));
if (status.Fail())
return status;
- // TODO: PTRACE_FORK | PTRACE_VFORK | PTRACE_POSIX_SPAWN?
- events.pe_set_event |= PTRACE_LWP_CREATE | PTRACE_LWP_EXIT;
+ // TODO: PTRACE_POSIX_SPAWN?
+ events.pe_set_event |= PTRACE_LWP_CREATE | PTRACE_LWP_EXIT | PTRACE_FORK |
+ PTRACE_VFORK | PTRACE_VFORK_DONE;
status = PtraceWrapper(PT_SET_EVENT_MASK, GetID(), &events, sizeof(events));
if (status.Fail())
return status;
@@ -974,3 +993,39 @@
return error;
}
+
+void NativeProcessNetBSD::MonitorClone(::pid_t child_pid) {
+ Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
+ LLDB_LOG(log, "clone, child_pid={0}", child_pid);
+
+ int status;
+ ::pid_t wait_pid =
+ llvm::sys::RetryAfterSignal(-1, ::waitpid, child_pid, &status, 0);
+ if (wait_pid != child_pid) {
+ LLDB_LOG(log,
+ "waiting for pid {0} failed. Assuming the pid has "
+ "disappeared in the meantime",
+ child_pid);
+ return;
+ }
+ if (WIFEXITED(status)) {
+ LLDB_LOG(log,
+ "waiting for pid {0} returned an 'exited' event. Not "
+ "tracking it.",
+ child_pid);
+ return;
+ }
+
+ MainLoop unused_loop;
+ NativeProcessNetBSD child_process{static_cast<::pid_t>(child_pid),
+ m_terminal_fd, *m_delegates[0], m_arch,
+ unused_loop};
+ child_process.Detach();
+ Status pt_error =
+ PtraceWrapper(PT_CONTINUE, GetID(), reinterpret_cast<void *>(1), 0);
+ if (pt_error.Fail()) {
+ LLDB_LOG_ERROR(log, std::move(pt_error.ToError()),
+ "unable to resume parent process {1}: {0}", GetID());
+ SetState(StateType::eStateInvalid);
+ }
+}
Index: lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
===================================================================
--- lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
+++ lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
@@ -157,7 +157,7 @@
void MonitorCallback(lldb::pid_t pid, bool exited, WaitStatus status);
- void WaitForNewThread(::pid_t tid);
+ void WaitForCloneNotification(::pid_t pid);
void MonitorSIGTRAP(const siginfo_t &info, NativeThreadLinux &thread);
@@ -234,6 +234,21 @@
/// Manages Intel PT process and thread traces.
IntelPTManager m_intel_pt_manager;
+
+ struct CloneInfo {
+ int event;
+ lldb::tid_t parent_tid;
+ };
+
+ // Map of child processes that have been signaled once, and we are
+ // waiting for the second signal.
+ llvm::DenseMap<lldb::pid_t, llvm::Optional<CloneInfo>> m_pending_pid_map;
+
+ // Handle a clone()-like event. If received by parent, clone_info contains
+ // additional info. Returns true if the event is handled, or false if it
+ // is pending second notification.
+ bool MonitorClone(lldb::pid_t child_pid,
+ llvm::Optional<CloneInfo> clone_info);
};
} // namespace process_linux
Index: lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
===================================================================
--- lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -30,6 +30,7 @@
#include "lldb/Host/PseudoTerminal.h"
#include "lldb/Host/ThreadLauncher.h"
#include "lldb/Host/common/NativeRegisterContext.h"
+#include "lldb/Host/linux/Host.h"
#include "lldb/Host/linux/Ptrace.h"
#include "lldb/Host/linux/Uio.h"
#include "lldb/Host/posix/ProcessLauncherPosixFork.h"
@@ -383,14 +384,22 @@
ptrace_opts |= PTRACE_O_TRACEEXIT;
// Have the tracer trace threads which spawn in the inferior process.
- // TODO: if we want to support tracing the inferiors' child, add the
- // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
ptrace_opts |= PTRACE_O_TRACECLONE;
// Have the tracer notify us before execve returns (needed to disable legacy
// SIGTRAP generation)
ptrace_opts |= PTRACE_O_TRACEEXEC;
+ // Have the tracer trace forked children.
+ ptrace_opts |= PTRACE_O_TRACEFORK;
+
+ // Have the tracer trace vforks.
+ ptrace_opts |= PTRACE_O_TRACEVFORK;
+
+ // Have the tracer trace vfork-done in order to restore breakpoints after
+ // the child finishes sharing memory.
+ ptrace_opts |= PTRACE_O_TRACEVFORKDONE;
+
return PtraceWrapper(PTRACE_SETOPTIONS, pid, nullptr, (void *)ptrace_opts);
}
@@ -444,8 +453,7 @@
LLDB_LOG(log, "tid {0}, si_code: {1}, si_pid: {2}", pid, info.si_code,
info.si_pid);
- NativeThreadLinux &thread = AddThread(pid, /*resume*/ true);
- ThreadWasCreated(thread);
+ MonitorClone(pid, llvm::None);
return;
}
@@ -509,29 +517,24 @@
}
}
-void NativeProcessLinux::WaitForNewThread(::pid_t tid) {
+void NativeProcessLinux::WaitForCloneNotification(::pid_t pid) {
Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
- if (GetThreadByID(tid)) {
- // We are already tracking the thread - we got the event on the new thread
- // (see MonitorSignal) before this one. We are done.
- return;
- }
-
- // The thread is not tracked yet, let's wait for it to appear.
+ // The PID is not tracked yet, let's wait for it to appear.
int status = -1;
LLDB_LOG(log,
- "received thread creation event for tid {0}. tid not tracked "
- "yet, waiting for thread to appear...",
- tid);
- ::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, tid, &status, __WALL);
- // Since we are waiting on a specific tid, this must be the creation event.
+ "received clone event for pid {0}. pid not tracked yet, "
+ "waiting for it to appear...",
+ pid);
+ ::pid_t wait_pid =
+ llvm::sys::RetryAfterSignal(-1, ::waitpid, pid, &status, __WALL);
+ // Since we are waiting on a specific pid, this must be the creation event.
// But let's do some checks just in case.
- if (wait_pid != tid) {
+ if (wait_pid != pid) {
LLDB_LOG(log,
- "waiting for tid {0} failed. Assuming the thread has "
+ "waiting for pid {0} failed. Assuming the pid has "
"disappeared in the meantime",
- tid);
+ pid);
// The only way I know of this could happen is if the whole process was
// SIGKILLed in the mean time. In any case, we can't do anything about that
// now.
@@ -539,17 +542,15 @@
}
if (WIFEXITED(status)) {
LLDB_LOG(log,
- "waiting for tid {0} returned an 'exited' event. Not "
- "tracking the thread.",
- tid);
+ "waiting for pid {0} returned an 'exited' event. Not "
+ "tracking it.",
+ pid);
// Also a very improbable event.
+ m_pending_pid_map.erase(pid);
return;
}
- LLDB_LOG(log, "pid = {0}: tracking new thread tid {1}", GetID(), tid);
- NativeThreadLinux &new_thread = AddThread(tid, /*resume*/ true);
-
- ThreadWasCreated(new_thread);
+ MonitorClone(pid, llvm::None);
}
void NativeProcessLinux::MonitorSIGTRAP(const siginfo_t &info,
@@ -560,26 +561,26 @@
assert(info.si_signo == SIGTRAP && "Unexpected child signal!");
switch (info.si_code) {
- // TODO: these two cases are required if we want to support tracing of the
- // inferiors' children. We'd need this to debug a monitor. case (SIGTRAP |
- // (PTRACE_EVENT_FORK << 8)): case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
-
+ case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):
+ case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)): {
- // This is the notification on the parent thread which informs us of new
- // thread creation. We don't want to do anything with the parent thread so
- // we just resume it. In case we want to implement "break on thread
- // creation" functionality, we would need to stop here.
+ // This can either mean a new thread or a new process spawned via
+ // clone(2) without SIGCHLD or CLONE_VFORK flag. Note that clone(2)
+ // can also cause PTRACE_EVENT_FORK and PTRACE_EVENT_VFORK if one
+ // of these flags are passed.
unsigned long event_message = 0;
if (GetEventMessage(thread.GetID(), &event_message).Fail()) {
LLDB_LOG(log,
- "pid {0} received thread creation event but "
- "GetEventMessage failed so we don't know the new tid",
+ "pid {0} received clone() event but GetEventMessage failed "
+ "so we don't know the new pid/tid",
thread.GetID());
- } else
- WaitForNewThread(event_message);
+ ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER);
+ } else {
+ if (!MonitorClone(event_message, {{(info.si_code >> 8), thread.GetID()}}))
+ WaitForCloneNotification(event_message);
+ }
- ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER);
break;
}
@@ -645,6 +646,11 @@
break;
}
+ case (SIGTRAP | (PTRACE_EVENT_VFORK_DONE << 8)): {
+ ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER);
+ break;
+ }
+
case 0:
case TRAP_TRACE: // We receive this on single stepping.
case TRAP_HWBKPT: // We receive this on watchpoint hit
@@ -854,6 +860,79 @@
StopRunningThreads(thread.GetID());
}
+bool NativeProcessLinux::MonitorClone(
+ lldb::pid_t child_pid,
+ llvm::Optional<NativeProcessLinux::CloneInfo> clone_info) {
+ Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
+ LLDB_LOG(log, "clone, child_pid={0}, clone info?={1}", child_pid,
+ clone_info.hasValue());
+
+ auto find_it = m_pending_pid_map.find(child_pid);
+ if (find_it == m_pending_pid_map.end()) {
+ // not in the map, so this is the first signal for the PID
+ m_pending_pid_map.insert({child_pid, clone_info});
+ return false;
+ }
+ m_pending_pid_map.erase(find_it);
+
+ // second signal for the pid
+ assert(clone_info.hasValue() != find_it->second.hasValue());
+ if (!clone_info) {
+ // child signal does not indicate the event, so grab the one stored
+ // earlier
+ clone_info = find_it->second;
+ }
+
+ LLDB_LOG(log, "second signal for child_pid={0}, parent_tid={1}, event={2}",
+ child_pid, clone_info->parent_tid, clone_info->event);
+
+ auto *parent_thread = GetThreadByID(clone_info->parent_tid);
+ assert(parent_thread);
+
+ switch (clone_info->event) {
+ case PTRACE_EVENT_CLONE: {
+ // PTRACE_EVENT_CLONE can either mean a new thread or a new process.
+ // Try to grab the new process' PGID to figure out which one it is.
+ // If PGID is the same as the PID, then it's a new process. Otherwise,
+ // it's a thread.
+ auto tgid_ret = getPIDForTID(child_pid);
+ if (tgid_ret != child_pid) {
+ // A new thread should have PGID matching our process' PID.
+ assert(!tgid_ret || tgid_ret.getValue() == GetID());
+
+ NativeThreadLinux &child_thread = AddThread(child_pid, /*resume*/ true);
+ // Resume the newly created thread.
+ ResumeThread(child_thread, eStateRunning, LLDB_INVALID_SIGNAL_NUMBER);
+ ThreadWasCreated(child_thread);
+
+ // Resume the parent.
+ ResumeThread(*parent_thread, parent_thread->GetState(),
+ LLDB_INVALID_SIGNAL_NUMBER);
+ break;
+ }
+ }
+ LLVM_FALLTHROUGH;
+ case PTRACE_EVENT_FORK:
+ case PTRACE_EVENT_VFORK: {
+ MainLoop unused_loop;
+ NativeProcessLinux child_process{static_cast<::pid_t>(child_pid),
+ m_terminal_fd,
+ *m_delegates[0],
+ m_arch,
+ unused_loop,
+ {static_cast<::pid_t>(child_pid)}};
+ child_process.Detach();
+ ResumeThread(*parent_thread, parent_thread->GetState(),
+ LLDB_INVALID_SIGNAL_NUMBER);
+ break;
+ }
+ default:
+ llvm_unreachable("unknown clone_info.event");
+ }
+
+ return true;
+}
+
bool NativeProcessLinux::SupportHardwareSingleStepping() const {
if (m_arch.GetMachine() == llvm::Triple::arm || m_arch.IsMIPS())
return false;
Index: lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.h
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.h
+++ lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.h
@@ -55,6 +55,8 @@
llvm::Error
CopyHardwareWatchpointsFrom(NativeRegisterContextFreeBSD &source) override;
+ llvm::Error ClearDBRegs() override;
+
private:
// Private member types.
enum RegSetKind {
Index: lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.cpp
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.cpp
+++ lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_x86_64.cpp
@@ -653,4 +653,10 @@
return YMMSplitPtr{&fpreg->sv_xmm[reg_index], &ymmreg[reg_index]};
}
+llvm::Error NativeRegisterContextFreeBSD_x86_64::ClearDBRegs() {
+ uint64_t zero = 0;
+ RegisterValue dr7{zero};
+ return WriteRegister(GetDR(7), dr7).ToError();
+}
+
#endif // defined(__x86_64__)
Index: lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.h
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.h
+++ lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.h
@@ -58,6 +58,8 @@
llvm::Error
CopyHardwareWatchpointsFrom(NativeRegisterContextFreeBSD &source) override;
+ llvm::Error ClearDBRegs() override;
+
private:
// Due to alignment, FreeBSD reg/fpreg are a few bytes larger than
// LLDB's GPR/FPU structs. However, all fields have matching offsets
Index: lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.cpp
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.cpp
+++ lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD_arm64.cpp
@@ -285,4 +285,19 @@
#endif
}
+llvm::Error NativeRegisterContextFreeBSD_arm64::ClearDBRegs() {
+#ifdef LLDB_HAS_FREEBSD_WATCHPOINT
+ if (llvm::Error error = ReadHardwareDebugInfo())
+ return error;
+
+ for (uint32_t i = 0; i < m_max_hbp_supported; i++)
+ m_hbp_regs[i].control = 0;
+ for (uint32_t i = 0; i < m_max_hwp_supported; i++)
+ m_hwp_regs[i].control = 0;
+ return WriteHardwareDebugRegs(eDREGTypeWATCH);
+#else
+ return llvm::error::success();
+#endif
+}
+
#endif // defined (__aarch64__)
Index: lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD.h
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD.h
+++ lldb/source/Plugins/Process/FreeBSD/NativeRegisterContextFreeBSD.h
@@ -32,6 +32,8 @@
virtual llvm::Error
CopyHardwareWatchpointsFrom(NativeRegisterContextFreeBSD &source) = 0;
+ virtual llvm::Error ClearDBRegs() { return llvm::Error::success(); }
+
protected:
virtual NativeProcessFreeBSD &GetProcess();
virtual ::pid_t GetProcessPid();
Index: lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.h
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.h
+++ lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.h
@@ -113,6 +113,7 @@
void MonitorSIGSTOP(lldb::pid_t pid);
void MonitorSIGTRAP(lldb::pid_t pid);
void MonitorSignal(lldb::pid_t pid, int signal);
+ void MonitorClone(::pid_t child_pid);
Status PopulateMemoryRegionCache();
void SigchldHandler();
Index: lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.cpp
===================================================================
--- lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.cpp
+++ lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.cpp
@@ -247,6 +247,19 @@
return;
}
+ if (info.pl_flags & PL_FLAG_FORKED) {
+ MonitorClone(info.pl_child_pid);
+ return;
+ }
+
+ if (info.pl_flags & PL_FLAG_VFORK_DONE) {
+ Status error =
+ PtraceWrapper(PT_CONTINUE, pid, reinterpret_cast<void *>(1), 0);
+ if (error.Fail())
+ SetState(StateType::eStateInvalid);
+ return;
+ }
+
if (info.pl_lwpid > 0) {
for (const auto &t : m_threads) {
if (t->GetID() == static_cast<lldb::tid_t>(info.pl_lwpid))
@@ -705,17 +718,17 @@
void NativeProcessFreeBSD::SigchldHandler() {
Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
- // Process all pending waitpid notifications.
int status;
::pid_t wait_pid =
llvm::sys::RetryAfterSignal(-1, waitpid, GetID(), &status, WNOHANG);
if (wait_pid == 0)
- return; // We are done.
+ return;
if (wait_pid == -1) {
Status error(errno, eErrorTypePOSIX);
LLDB_LOG(log, "waitpid ({0}, &status, _) failed: {1}", GetID(), error);
+ return;
}
WaitStatus wait_status = WaitStatus::Decode(status);
@@ -885,7 +898,7 @@
PtraceWrapper(PT_GET_EVENT_MASK, GetID(), &events, sizeof(events));
if (status.Fail())
return status;
- events |= PTRACE_LWP;
+ events |= PTRACE_LWP | PTRACE_FORK | PTRACE_VFORK;
status = PtraceWrapper(PT_SET_EVENT_MASK, GetID(), &events, sizeof(events));
if (status.Fail())
return status;
@@ -919,3 +932,53 @@
bool NativeProcessFreeBSD::SupportHardwareSingleStepping() const {
return !m_arch.IsMIPS();
}
+
+void NativeProcessFreeBSD::MonitorClone(::pid_t child_pid) {
+ Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
+ LLDB_LOG(log, "fork, child_pid={0}", child_pid);
+
+ int status;
+ ::pid_t wait_pid =
+ llvm::sys::RetryAfterSignal(-1, ::waitpid, child_pid, &status, 0);
+ if (wait_pid != child_pid) {
+ LLDB_LOG(log,
+ "waiting for pid {0} failed. Assuming the pid has "
+ "disappeared in the meantime",
+ child_pid);
+ return;
+ }
+ if (WIFEXITED(status)) {
+ LLDB_LOG(log,
+ "waiting for pid {0} returned an 'exited' event. Not "
+ "tracking it.",
+ child_pid);
+ return;
+ }
+
+ MainLoop unused_loop;
+ NativeProcessFreeBSD child_process{static_cast<::pid_t>(child_pid),
+ m_terminal_fd, *m_delegates[0], m_arch,
+ unused_loop};
+ child_process.ReinitializeThreads();
+ auto *child_thread =
+ static_cast<NativeThreadFreeBSD *>(child_process.GetCurrentThread());
+ assert(child_thread);
+ // new processes inherit dbregs, so we need to clear them
+ llvm::Error error = child_thread->GetRegisterContext().ClearDBRegs();
+ if (error) {
+ LLDB_LOG_ERROR(log, std::move(error),
+ "failed to clear dbregs in forked process {1}: {0}",
+ child_pid);
+ SetState(StateType::eStateInvalid);
+ return;
+ }
+
+ child_process.Detach();
+ Status pt_error =
+ PtraceWrapper(PT_CONTINUE, GetID(), reinterpret_cast<void *>(1), 0);
+ if (pt_error.Fail()) {
+ LLDB_LOG_ERROR(log, pt_error.ToError(),
+ "unable to resume parent process {1}: {0}", GetID());
+ SetState(StateType::eStateInvalid);
+ }
+}
Index: lldb/source/Host/linux/Host.cpp
===================================================================
--- lldb/source/Host/linux/Host.cpp
+++ lldb/source/Host/linux/Host.cpp
@@ -27,6 +27,7 @@
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
+#include "lldb/Host/linux/Host.h"
#include "lldb/Host/linux/Support.h"
#include "lldb/Utility/DataExtractor.h"
@@ -53,7 +54,8 @@
}
static bool GetStatusInfo(::pid_t Pid, ProcessInstanceInfo &ProcessInfo,
- ProcessState &State, ::pid_t &TracerPid) {
+ ProcessState &State, ::pid_t &TracerPid,
+ ::pid_t &Tgid) {
Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
auto BufferOrError = getProcFile(Pid, "status");
@@ -107,6 +109,9 @@
} else if (Line.consume_front("TracerPid:")) {
Line = Line.ltrim();
Line.consumeInteger(10, TracerPid);
+ } else if (Line.consume_front("Tgid:")) {
+ Line = Line.ltrim();
+ Line.consumeInteger(10, Tgid);
}
}
return true;
@@ -204,6 +209,7 @@
static bool GetProcessAndStatInfo(::pid_t pid,
ProcessInstanceInfo &process_info,
ProcessState &State, ::pid_t &tracerpid) {
+ ::pid_t tgid;
tracerpid = 0;
process_info.Clear();
@@ -214,7 +220,7 @@
GetProcessEnviron(pid, process_info);
// Get User and Group IDs and get tracer pid.
- if (!GetStatusInfo(pid, process_info, State, tracerpid))
+ if (!GetStatusInfo(pid, process_info, State, tracerpid, tgid))
return false;
return true;
@@ -308,3 +314,14 @@
Status Host::ShellExpandArguments(ProcessLaunchInfo &launch_info) {
return Status("unimplemented");
}
+
+llvm::Optional<lldb::pid_t> lldb_private::getPIDForTID(lldb::pid_t tid) {
+ ::pid_t tracerpid, tgid = LLDB_INVALID_PROCESS_ID;
+ ProcessInstanceInfo process_info;
+ ProcessState state;
+
+ if (!GetStatusInfo(tid, process_info, state, tracerpid, tgid) ||
+ tgid == LLDB_INVALID_PROCESS_ID)
+ return llvm::None;
+ return tgid;
+}
Index: lldb/include/lldb/Host/linux/Host.h
===================================================================
--- /dev/null
+++ lldb/include/lldb/Host/linux/Host.h
@@ -0,0 +1,22 @@
+//===-- Host.h --------------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_HOST_LINUX_HOST_H
+#define LLDB_HOST_LINUX_HOST_H
+
+#include "lldb/lldb-types.h"
+#include "llvm/ADT/Optional.h"
+
+namespace lldb_private {
+
+// Get PID (i.e. the primary thread ID) corresponding to the specified TID.
+llvm::Optional<lldb::pid_t> getPIDForTID(lldb::pid_t tid);
+
+} // namespace lldb_private
+
+#endif // #ifndef LLDB_HOST_LINUX_HOST_H
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