[haiku-commits] r35620 - in haiku/trunk: headers/private/kernel src/system/kernel/arch/x86 src/system/kernel/debug
- From: ingo_weinhold@xxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Thu, 25 Feb 2010 21:20:16 +0100 (CET)
Author: bonefish
Date: 2010-02-25 21:20:16 +0100 (Thu, 25 Feb 2010)
New Revision: 35620
Changeset: http://dev.haiku-os.org/changeset/35620/haiku
Ticket: http://dev.haiku-os.org/ticket/3487
Modified:
haiku/trunk/headers/private/kernel/user_debugger.h
haiku/trunk/src/system/kernel/arch/x86/arch_user_debugger.cpp
haiku/trunk/src/system/kernel/debug/user_debugger.cpp
Log:
Correctly handle cases when a thread single-steps into the kernel as it can
happen on syscalls or "int" instructions. The debug exception handler sets
the thread debug flags B_THREAD_DEBUG_STOP and
B_THREAD_DEBUG_NOTIFY_SINGLE_STEP (new) and lets the thread continue. Before
leaving the kernel the thread is stopped and a single-step notification is
sent. Fixes #3487.
Modified: haiku/trunk/headers/private/kernel/user_debugger.h
===================================================================
--- haiku/trunk/headers/private/kernel/user_debugger.h 2010-02-25 19:10:44 UTC
(rev 35619)
+++ haiku/trunk/headers/private/kernel/user_debugger.h 2010-02-25 20:20:16 UTC
(rev 35620)
@@ -154,17 +154,18 @@
// thread debugging flags (user-specifiable flags are in <debugger.h>)
enum {
- B_THREAD_DEBUG_INITIALIZED = 0x0001,
- B_THREAD_DEBUG_DYING = 0x0002,
- B_THREAD_DEBUG_STOP = 0x0004,
- B_THREAD_DEBUG_STOPPED = 0x0008,
- B_THREAD_DEBUG_SINGLE_STEP = 0x0010,
+ B_THREAD_DEBUG_INITIALIZED = 0x0001,
+ B_THREAD_DEBUG_DYING = 0x0002,
+ B_THREAD_DEBUG_STOP = 0x0004,
+ B_THREAD_DEBUG_STOPPED = 0x0008,
+ B_THREAD_DEBUG_SINGLE_STEP = 0x0010,
+ B_THREAD_DEBUG_NOTIFY_SINGLE_STEP = 0x0020,
- B_THREAD_DEBUG_NUB_THREAD = 0x0020, // marks the
nub thread
+ B_THREAD_DEBUG_NUB_THREAD = 0x0040, //
marks the nub thread
- B_THREAD_DEBUG_KERNEL_FLAG_MASK = 0xffff,
+ B_THREAD_DEBUG_KERNEL_FLAG_MASK = 0xffff,
- B_THREAD_DEBUG_DEFAULT_FLAGS = 0,
+ B_THREAD_DEBUG_DEFAULT_FLAGS = 0,
};
// messages sent from the debug nub thread to a debugged thread
Modified: haiku/trunk/src/system/kernel/arch/x86/arch_user_debugger.cpp
===================================================================
--- haiku/trunk/src/system/kernel/arch/x86/arch_user_debugger.cpp
2010-02-25 19:10:44 UTC (rev 35619)
+++ haiku/trunk/src/system/kernel/arch/x86/arch_user_debugger.cpp
2010-02-25 20:20:16 UTC (rev 35620)
@@ -886,7 +886,42 @@
// it, but we don't want it when continuing otherwise.
frame->flags &= ~(1 << X86_EFLAGS_TF);
- panic("kernel single step");
+ // Determine whether the exception occurred at a
syscall/trap
+ // kernel entry or whether this is genuine kernel
single-stepping.
+ bool inKernel = true;
+ struct thread* thread = thread_get_current_thread();
+ if (thread->team != team_get_kernel_team()
+ && i386_get_user_iframe() == NULL) {
+ // TODO: This is not yet fully correct, since a
newly created
+ // thread that doesn't have entered userland
yet also has this
+ // property.
+ inKernel = false;
+ }
+
+ if (inKernel) {
+ panic("kernel single step");
+ } else {
+ // The thread is a userland thread and it just
entered the
+ // kernel when the single-step exception
occurred. This happens
+ // e.g. when sysenter is called with
single-stepping enabled.
+ // We need to ignore the exception now and send
a single-step
+ // notification later, when the thread wants to
return from the
+ // kernel.
+ InterruptsSpinLocker
threadLocker(gThreadSpinlock);
+
+ // Check whether the team is still being
debugged and set
+ // the B_THREAD_DEBUG_NOTIFY_SINGLE_STEP and
+ // B_THREAD_DEBUG_STOP flags, so that the
thread will be
+ // stopped when it is going to leave the kernel
and notify the
+ // debugger about the single-step event.
+ int32 teamDebugFlags
+ =
atomic_get(&thread->team->debug_info.flags);
+ if (teamDebugFlags &
B_TEAM_DEBUG_DEBUGGER_INSTALLED) {
+ atomic_or(&thread->debug_info.flags,
+
B_THREAD_DEBUG_NOTIFY_SINGLE_STEP
+ | B_THREAD_DEBUG_STOP);
+ }
+ }
}
} else if (dr6 & (1 << X86_DR6_BT)) {
// task switch
Modified: haiku/trunk/src/system/kernel/debug/user_debugger.cpp
===================================================================
--- haiku/trunk/src/system/kernel/debug/user_debugger.cpp 2010-02-25
19:10:44 UTC (rev 35619)
+++ haiku/trunk/src/system/kernel/debug/user_debugger.cpp 2010-02-25
20:20:16 UTC (rev 35620)
@@ -954,11 +954,25 @@
void
user_debug_stop_thread()
{
- // prepare the message
- debug_thread_debugged message;
+ // check whether this is actually an emulated single-step notification
+ InterruptsSpinLocker threadsLocker(gThreadSpinlock);
+ struct thread* thread = thread_get_current_thread();
+ bool singleStepped = false;
+ if ((atomic_and(&thread->debug_info.flags,
+ ~B_THREAD_DEBUG_NOTIFY_SINGLE_STEP)
+ & B_THREAD_DEBUG_NOTIFY_SINGLE_STEP) != 0) {
+ singleStepped = true;
+ }
- thread_hit_serious_debug_event(B_DEBUGGER_MESSAGE_THREAD_DEBUGGED,
&message,
- sizeof(message));
+ threadsLocker.Unlock();
+
+ if (singleStepped) {
+ user_debug_single_stepped();
+ } else {
+ debug_thread_debugged message;
+
thread_hit_serious_debug_event(B_DEBUGGER_MESSAGE_THREAD_DEBUGGED,
+ &message, sizeof(message));
+ }
}
Other related posts:
- » [haiku-commits] r35620 - in haiku/trunk: headers/private/kernel src/system/kernel/arch/x86 src/system/kernel/debug - ingo_weinhold
