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-rw-r--r--Kernel/Arch/i386/CPU.cpp61
-rw-r--r--Kernel/Arch/i386/CPU.h70
-rw-r--r--Kernel/Lock.cpp15
-rw-r--r--Kernel/Process.cpp46
-rw-r--r--Kernel/Process.h3
-rw-r--r--Kernel/Scheduler.cpp31
-rw-r--r--Kernel/SpinLock.h41
-rw-r--r--Kernel/Thread.cpp50
-rw-r--r--Kernel/Thread.h4
-rw-r--r--Kernel/VM/MemoryManager.cpp5
-rw-r--r--Kernel/VM/MemoryManager.h1
-rw-r--r--Kernel/WaitQueue.cpp10
12 files changed, 242 insertions, 95 deletions
diff --git a/Kernel/Arch/i386/CPU.cpp b/Kernel/Arch/i386/CPU.cpp
index 8a65051fbe..b7b8d5bbd6 100644
--- a/Kernel/Arch/i386/CPU.cpp
+++ b/Kernel/Arch/i386/CPU.cpp
@@ -828,6 +828,10 @@ void Processor::early_initialize(u32 cpu)
m_cpu = cpu;
m_in_irq = 0;
+ m_in_critical = 0;
+
+ m_invoke_scheduler_async = false;
+ m_scheduler_initialized = false;
m_idle_thread = nullptr;
m_current_thread = nullptr;
@@ -961,9 +965,10 @@ extern "C" void enter_thread_context(Thread* from_thread, Thread* to_thread)
void Processor::switch_context(Thread* from_thread, Thread* to_thread)
{
ASSERT(!in_irq());
+ ASSERT(!m_in_critical);
ASSERT(is_kernel_mode());
#ifdef CONTEXT_SWITCH_DEBUG
- dbg() << "switch_context --> switching out of: " << *from_thread;
+ dbg() << "switch_context --> switching out of: " << VirtualAddress(from_thread) << " " << *from_thread;
#endif
// Switch to new thread context, passing from_thread and to_thread
@@ -1006,7 +1011,7 @@ void Processor::switch_context(Thread* from_thread, Thread* to_thread)
[to_thread] "a" (to_thread)
);
#ifdef CONTEXT_SWITCH_DEBUG
- dbg() << "switch_context <-- from " << *from_thread << " to " << *to_thread;
+ dbg() << "switch_context <-- from " << VirtualAddress(from_thread) << " " << *from_thread << " to " << VirtualAddress(to_thread) << " " << *to_thread;
#endif
}
@@ -1017,9 +1022,14 @@ extern "C" void context_first_init(Thread* from_thread, Thread* to_thread, TrapF
(void)from_thread;
(void)to_thread;
(void)trap;
+
+ ASSERT(to_thread == Thread::current());
#ifdef CONTEXT_SWITCH_DEBUG
- dbg() << "switch_context <-- from " << *from_thread << " to " << *to_thread << " (context_first_init)";
+ dbg() << "switch_context <-- from " << VirtualAddress(from_thread) << " " << *from_thread << " to " << VirtualAddress(to_thread) << " " << *to_thread << " (context_first_init)";
#endif
+ if (to_thread->process().wait_for_tracer_at_next_execve()) {
+ to_thread->send_urgent_signal_to_self(SIGSTOP);
+ }
}
extern "C" void thread_context_first_enter(void);
@@ -1038,9 +1048,15 @@ asm(
" jmp common_trap_exit \n"
);
-u32 Processor::init_context(Thread& thread)
+u32 Processor::init_context(Thread& thread, bool leave_crit)
{
ASSERT(is_kernel_mode());
+ if (leave_crit) {
+ ASSERT(in_critical());
+ m_in_critical--; // leave it without triggering anything
+ ASSERT(!in_critical());
+ }
+
const u32 kernel_stack_top = thread.kernel_stack_top();
u32 stack_top = kernel_stack_top;
@@ -1098,7 +1114,10 @@ u32 Processor::init_context(Thread& thread)
*reinterpret_cast<u32*>(stack_top) = stack_top + 4;
#ifdef CONTEXT_SWITCH_DEBUG
- dbg() << "init_context " << thread << " set up to execute at eip: " << VirtualAddress(tss.eip) << " esp: " << VirtualAddress(tss.esp) << " stack top: " << VirtualAddress(stack_top);
+ if (return_to_user)
+ dbg() << "init_context " << thread << " (" << VirtualAddress(&thread) << ") set up to execute at eip: " << String::format("%02x:%08x", iretframe.cs, (u32)tss.eip) << " esp: " << VirtualAddress(tss.esp) << " stack top: " << VirtualAddress(stack_top) << " user esp: " << String::format("%02x:%08x", iretframe.userspace_ss, (u32)iretframe.userspace_esp);
+ else
+ dbg() << "init_context " << thread << " (" << VirtualAddress(&thread) << ") set up to execute at eip: " << String::format("%02x:%08x", iretframe.cs, (u32)tss.eip) << " esp: " << VirtualAddress(tss.esp) << " stack top: " << VirtualAddress(stack_top);
#endif
// make switch_context() always first return to thread_context_first_enter()
@@ -1118,24 +1137,29 @@ u32 Processor::init_context(Thread& thread)
}
-extern "C" u32 do_init_context(Thread* thread)
+extern "C" u32 do_init_context(Thread* thread, u32 flags)
{
- return Processor::init_context(*thread);
+ ASSERT_INTERRUPTS_DISABLED();
+ ASSERT(Processor::current().in_critical());
+ thread->tss().eflags = flags;
+ return Processor::current().init_context(*thread, true);
}
-extern "C" void do_assume_context(Thread* thread);
+extern "C" void do_assume_context(Thread* thread, u32 flags);
asm(
".global do_assume_context \n"
"do_assume_context: \n"
" movl 4(%esp), %ebx \n"
+" movl 8(%esp), %esi \n"
// We're going to call Processor::init_context, so just make sure
// we have enough stack space so we don't stomp over it
" subl $(" __STRINGIFY(4 + REGISTER_STATE_SIZE + TRAP_FRAME_SIZE + 4) "), %esp \n"
+" pushl %esi \n"
" pushl %ebx \n"
" cld \n"
" call do_init_context \n"
-" addl $4, %esp \n"
+" addl $8, %esp \n"
" movl %eax, %esp \n" // move stack pointer to what Processor::init_context set up for us
" pushl %ebx \n" // push to_thread
" pushl %ebx \n" // push from_thread
@@ -1143,9 +1167,13 @@ asm(
" jmp enter_thread_context \n"
);
-void Processor::assume_context(Thread& thread)
+void Processor::assume_context(Thread& thread, u32 flags)
{
- do_assume_context(&thread);
+#ifdef CONTEXT_SWITCH_DEBUG
+ dbg() << "Assume context for thread " << VirtualAddress(&thread) << " " << thread;
+#endif
+ ASSERT_INTERRUPTS_DISABLED();
+ do_assume_context(&thread, flags);
ASSERT_NOT_REACHED();
}
@@ -1161,6 +1189,7 @@ void Processor::initialize_context_switching(Thread& initial_thread)
m_tss.cs = m_tss.ds = m_tss.es = m_tss.gs = m_tss.ss = GDT_SELECTOR_CODE0 | 3;
m_tss.fs = GDT_SELECTOR_PROC | 3;
+ m_scheduler_initialized = true;
asm volatile(
"movl %[new_esp], %%esp \n" // swich to new stack
@@ -1197,7 +1226,15 @@ void Processor::exit_trap(TrapFrame& trap)
ASSERT(m_in_irq >= trap.prev_irq_level);
m_in_irq = trap.prev_irq_level;
- if (m_invoke_scheduler_async && !m_in_irq) {
+ if (!m_in_irq && !m_in_critical)
+ check_invoke_scheduler();
+}
+
+void Processor::check_invoke_scheduler()
+{
+ ASSERT(!m_in_irq);
+ ASSERT(!m_in_critical);
+ if (m_invoke_scheduler_async && m_scheduler_initialized) {
m_invoke_scheduler_async = false;
Scheduler::invoke_async();
}
diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h
index 6f6f7def92..bc41078a70 100644
--- a/Kernel/Arch/i386/CPU.h
+++ b/Kernel/Arch/i386/CPU.h
@@ -622,6 +622,7 @@ class Processor {
u32 m_cpu;
u32 m_in_irq;
+ u32 m_in_critical;
TSS32 m_tss;
static FPUState s_clean_fpu_state;
@@ -632,6 +633,7 @@ class Processor {
Thread* m_idle_thread;
bool m_invoke_scheduler_async;
+ bool m_scheduler_initialized;
void gdt_init();
void write_raw_gdt_entry(u16 selector, u32 low, u32 high);
@@ -713,11 +715,32 @@ public:
return m_in_irq;
}
+ ALWAYS_INLINE void enter_critical(u32& prev_flags)
+ {
+ m_in_critical++;
+ prev_flags = cpu_flags();
+ cli();
+ }
+
+ ALWAYS_INLINE void leave_critical(u32 prev_flags)
+ {
+ ASSERT(m_in_critical > 0);
+ if (--m_in_critical == 0) {
+ if (!m_in_irq)
+ check_invoke_scheduler();
+ }
+ if (prev_flags & 0x200)
+ sti();
+ }
+
+ ALWAYS_INLINE u32& in_critical() { return m_in_critical; }
+
ALWAYS_INLINE const FPUState& clean_fpu_state() const
{
return s_clean_fpu_state;
}
+ void check_invoke_scheduler();
void invoke_scheduler_async() { m_invoke_scheduler_async = true; }
void enter_trap(TrapFrame& trap, bool raise_irq);
@@ -725,12 +748,55 @@ public:
[[noreturn]] void initialize_context_switching(Thread& initial_thread);
void switch_context(Thread* from_thread, Thread* to_thread);
- [[noreturn]] static void assume_context(Thread& thread);
- static u32 init_context(Thread& thread);
+ [[noreturn]] static void assume_context(Thread& thread, u32 flags);
+ u32 init_context(Thread& thread, bool leave_crit);
void set_thread_specific(u8* data, size_t len);
};
+class ScopedCritical
+{
+ u32 m_prev_flags;
+ bool m_valid;
+
+public:
+ ScopedCritical(const ScopedCritical&) = delete;
+ ScopedCritical& operator=(const ScopedCritical&) = delete;
+
+ ScopedCritical()
+ {
+ m_valid = true;
+ Processor::current().enter_critical(m_prev_flags);
+ }
+
+ ~ScopedCritical()
+ {
+ if (m_valid) {
+ m_valid = false;
+ Processor::current().leave_critical(m_prev_flags);
+ }
+ }
+
+ ScopedCritical(ScopedCritical&& from):
+ m_prev_flags(from.m_prev_flags),
+ m_valid(from.m_valid)
+ {
+ from.m_prev_flags = 0;
+ from.m_valid = false;
+ }
+
+ ScopedCritical& operator=(ScopedCritical&& from)
+ {
+ if (&from != this) {
+ m_prev_flags = from.m_prev_flags;
+ m_valid = from.m_valid;
+ from.m_prev_flags = 0;
+ from.m_valid = false;
+ }
+ return *this;
+ }
+};
+
struct TrapFrame {
u32 prev_irq_level;
RegisterState* regs; // must be last
diff --git a/Kernel/Lock.cpp b/Kernel/Lock.cpp
index 4f6ec943af..05d516d672 100644
--- a/Kernel/Lock.cpp
+++ b/Kernel/Lock.cpp
@@ -24,6 +24,7 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#include <AK/TemporaryChange.h>
#include <Kernel/KSyms.h>
#include <Kernel/Lock.h>
#include <Kernel/Thread.h>
@@ -67,6 +68,13 @@ void Lock::lock(Mode mode)
}
timeval* timeout = nullptr;
current_thread->wait_on(m_queue, timeout, &m_lock, m_holder, m_name);
+ } else if (Processor::current().in_critical()) {
+ // If we're in a critical section and trying to lock, no context
+ // switch will happen, so yield.
+ // The assumption is that if we call this from a critical section
+ // that we DO want to temporarily leave it
+ TemporaryChange change(Processor::current().in_critical(), 0u);
+ Scheduler::yield();
}
}
}
@@ -95,6 +103,9 @@ void Lock::unlock()
return;
}
// I don't know *who* is using "m_lock", so just yield.
+ // The assumption is that if we call this from a critical section
+ // that we DO want to temporarily leave it
+ TemporaryChange change(Processor::current().in_critical(), 0u);
Scheduler::yield();
}
}
@@ -102,7 +113,7 @@ void Lock::unlock()
bool Lock::force_unlock_if_locked()
{
ASSERT(m_mode != Mode::Shared);
- InterruptDisabler disabler;
+ ScopedCritical critical;
if (m_holder != Thread::current())
return false;
ASSERT(m_times_locked == 1);
@@ -116,7 +127,7 @@ bool Lock::force_unlock_if_locked()
void Lock::clear_waiters()
{
ASSERT(m_mode != Mode::Shared);
- InterruptDisabler disabler;
+ ScopedCritical critical;
m_queue.clear();
}
diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index d4b804cd93..df83bd296a 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -84,10 +84,10 @@
#include <LibELF/Validation.h>
#include <LibKeyboard/CharacterMapData.h>
-#define PROCESS_DEBUG
+//#define PROCESS_DEBUG
//#define DEBUG_POLL_SELECT
//#define DEBUG_IO
-#define TASK_DEBUG
+//#define TASK_DEBUG
//#define FORK_DEBUG
//#define EXEC_DEBUG
//#define SIGNAL_DEBUG
@@ -821,9 +821,10 @@ void Process::kill_all_threads()
});
}
-int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Vector<String> arguments, Vector<String> environment, RefPtr<FileDescription> interpreter_description)
+int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Vector<String> arguments, Vector<String> environment, RefPtr<FileDescription> interpreter_description, Thread*& new_main_thread, u32& prev_flags)
{
ASSERT(is_ring3());
+ ASSERT(!Processor::current().in_critical());
auto path = main_program_description->absolute_path();
#ifdef EXEC_DEBUG
dbg() << "do_exec(" << path << ")";
@@ -867,7 +868,7 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
{
// Need to make sure we don't swap contexts in the middle
- InterruptDisabler disabler;
+ ScopedCritical critical;
old_page_directory = move(m_page_directory);
old_regions = move(m_regions);
m_page_directory = PageDirectory::create_for_userspace(*this);
@@ -910,7 +911,7 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
ArmedScopeGuard rollback_regions_guard([&]() {
ASSERT(Process::current() == this);
// Need to make sure we don't swap contexts in the middle
- InterruptDisabler disabler;
+ ScopedCritical critical;
m_page_directory = move(old_page_directory);
m_regions = move(old_regions);
MM.enter_process_paging_scope(*this);
@@ -963,6 +964,7 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
master_tls_alignment = alignment;
return master_tls_region->vaddr().as_ptr();
};
+ ASSERT(!Processor::current().in_critical());
bool success = loader->load();
if (!success) {
klog() << "do_exec: Failure loading " << path.characters();
@@ -1026,7 +1028,7 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
}
}
- Thread* new_main_thread = nullptr;
+ new_main_thread = nullptr;
if (&current_thread->process() == this) {
new_main_thread = current_thread;
} else {
@@ -1041,11 +1043,10 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
// and we don't want to deal with faults after this point.
u32 new_userspace_esp = new_main_thread->make_userspace_stack_for_main_thread(move(arguments), move(environment));
- // We cli() manually here because we don't want to get interrupted between do_exec() and Processor::assume_context().
- // The reason is that the task redirection we've set up above will be clobbered by the timer IRQ.
+ // We cli() manually here because we don't want to get interrupted between do_exec()
+ // and Processor::assume_context() or the next context switch.
// If we used an InterruptDisabler that sti()'d on exit, we might timer tick'd too soon in exec().
- if (&current_thread->process() == this)
- cli();
+ Processor::current().enter_critical(prev_flags);
// NOTE: Be careful to not trigger any page faults below!
@@ -1059,7 +1060,6 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
new_main_thread->make_thread_specific_region({});
new_main_thread->reset_fpu_state();
- // NOTE: if a context switch were to happen, tss.eip and tss.esp would get overwritten!!!
auto& tss = new_main_thread->m_tss;
tss.cs = GDT_SELECTOR_CODE3 | 3;
tss.ds = GDT_SELECTOR_DATA3 | 3;
@@ -1073,7 +1073,7 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
tss.ss2 = m_pid;
#ifdef TASK_DEBUG
- klog() << "Process exec'd " << path.characters() << " @ " << String::format("%p", entry_eip);
+ klog() << "Process " << VirtualAddress(this) << " thread " << VirtualAddress(new_main_thread) << " exec'd " << path.characters() << " @ " << String::format("%p", entry_eip);
#endif
if (was_profiling)
@@ -1081,6 +1081,8 @@ int Process::do_exec(NonnullRefPtr<FileDescription> main_program_description, Ve
new_main_thread->set_state(Thread::State::Skip1SchedulerPass);
big_lock().force_unlock_if_locked();
+ ASSERT_INTERRUPTS_DISABLED();
+ ASSERT(Processor::current().in_critical());
return 0;
}
@@ -1249,26 +1251,26 @@ int Process::exec(String path, Vector<String> arguments, Vector<String> environm
// The bulk of exec() is done by do_exec(), which ensures that all locals
// are cleaned up by the time we yield-teleport below.
- int rc = do_exec(move(description), move(arguments), move(environment), move(interpreter_description));
+ Thread* new_main_thread = nullptr;
+ u32 prev_flags = 0;
+ int rc = do_exec(move(description), move(arguments), move(environment), move(interpreter_description), new_main_thread, prev_flags);
m_exec_tid = 0;
if (rc < 0)
return rc;
- auto current_thread = Thread::current();
- if (m_wait_for_tracer_at_next_execve) {
- ASSERT(current_thread->state() == Thread::State::Skip1SchedulerPass);
- // State::Skip1SchedulerPass is irrelevant since we block the thread
- current_thread->set_state(Thread::State::Running);
- current_thread->send_urgent_signal_to_self(SIGSTOP);
- }
+ ASSERT_INTERRUPTS_DISABLED();
+ ASSERT(Processor::current().in_critical());
- if (&current_thread->process() == this) {
+ auto current_thread = Thread::current();
+ if (current_thread == new_main_thread) {
current_thread->set_state(Thread::State::Running);
- Processor::assume_context(*current_thread);
+ Processor::assume_context(*current_thread, prev_flags);
ASSERT_NOT_REACHED();
}
+
+ Processor::current().leave_critical(prev_flags);
return 0;
}
diff --git a/Kernel/Process.h b/Kernel/Process.h
index c595b9dd78..6592a9f787 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -450,6 +450,7 @@ public:
void increment_inspector_count(Badge<ProcessInspectionHandle>) { ++m_inspector_count; }
void decrement_inspector_count(Badge<ProcessInspectionHandle>) { --m_inspector_count; }
+ bool wait_for_tracer_at_next_execve() const { return m_wait_for_tracer_at_next_execve; }
void set_wait_for_tracer_at_next_execve(bool val) { m_wait_for_tracer_at_next_execve = val; }
KResultOr<u32> peek_user_data(u32* address);
@@ -470,7 +471,7 @@ private:
void kill_threads_except_self();
void kill_all_threads();
- int do_exec(NonnullRefPtr<FileDescription> main_program_description, Vector<String> arguments, Vector<String> environment, RefPtr<FileDescription> interpreter_description);
+ int do_exec(NonnullRefPtr<FileDescription> main_program_description, Vector<String> arguments, Vector<String> environment, RefPtr<FileDescription> interpreter_description, Thread*& new_main_thread, u32& prev_flags);
ssize_t do_write(FileDescription&, const u8*, int data_size);
KResultOr<NonnullRefPtr<FileDescription>> find_elf_interpreter_for_executable(const String& path, char (&first_page)[PAGE_SIZE], int nread, size_t file_size);
diff --git a/Kernel/Scheduler.cpp b/Kernel/Scheduler.cpp
index 1ef990c2bb..9d36b9eda7 100644
--- a/Kernel/Scheduler.cpp
+++ b/Kernel/Scheduler.cpp
@@ -327,7 +327,7 @@ void Scheduler::start()
idle_thread.set_ticks_left(time_slice_for(idle_thread));
idle_thread.did_schedule();
idle_thread.set_initialized(true);
- Processor::init_context(idle_thread);
+ processor.init_context(idle_thread, false);
idle_thread.set_state(Thread::Running);
ASSERT(idle_thread.affinity() == (1u << processor.id()));
processor.initialize_context_switching(idle_thread);
@@ -453,21 +453,23 @@ bool Scheduler::pick_next()
bool Scheduler::yield()
{
+ InterruptDisabler disabler;
auto& proc = Processor::current();
auto current_thread = Thread::current();
#ifdef SCHEDULER_DEBUG
- dbg() << "Scheduler[" << Processor::current().id() << "]: yielding thread " << *current_thread << " in_irq: " << proc.in_irq();
+ dbg() << "Scheduler[" << proc.id() << "]: yielding thread " << *current_thread << " in_irq: " << proc.in_irq();
#endif
- InterruptDisabler disabler;
ASSERT(current_thread != nullptr);
- if (proc.in_irq()) {
- // If we're handling an IRQ we can't switch context, delay until
- // exiting the trap
+ if (proc.in_irq() || proc.in_critical()) {
+ // If we're handling an IRQ we can't switch context, or we're in
+ // a critical section where we don't want to switch contexts, then
+ // delay until exiting the trap or critical section
proc.invoke_scheduler_async();
+ return false;
} else if (!Scheduler::pick_next())
return false;
#ifdef SCHEDULER_DEBUG
- dbg() << "Scheduler[" << Processor::current().id() << "]: yield returns to thread " << *current_thread << " in_irq: " << proc.in_irq();
+ dbg() << "Scheduler[" << proc.id() << "]: yield returns to thread " << *current_thread << " in_irq: " << proc.in_irq();
#endif
return true;
}
@@ -475,10 +477,16 @@ bool Scheduler::yield()
bool Scheduler::donate_to(Thread* beneficiary, const char* reason)
{
InterruptDisabler disabler;
- ASSERT(!Processor::current().in_irq());
+ auto& proc = Processor::current();
+ ASSERT(!proc.in_irq());
if (!Thread::is_thread(beneficiary))
return false;
+ if (proc.in_critical()) {
+ proc.invoke_scheduler_async();
+ return false;
+ }
+
(void)reason;
unsigned ticks_left = Thread::current()->ticks_left();
if (!beneficiary || beneficiary->state() != Thread::Runnable || ticks_left <= 1)
@@ -486,7 +494,7 @@ bool Scheduler::donate_to(Thread* beneficiary, const char* reason)
unsigned ticks_to_donate = min(ticks_left - 1, time_slice_for(*beneficiary));
#ifdef SCHEDULER_DEBUG
- dbg() << "Scheduler[" << Processor::current().id() << "]: Donating " << ticks_to_donate << " ticks to " << *beneficiary << ", reason=" << reason;
+ dbg() << "Scheduler[" << proc.id() << "]: Donating " << ticks_to_donate << " ticks to " << *beneficiary << ", reason=" << reason;
#endif
beneficiary->set_ticks_left(ticks_to_donate);
Scheduler::context_switch(*beneficiary);
@@ -513,13 +521,14 @@ bool Scheduler::context_switch(Thread& thread)
#endif
}
+ auto& proc = Processor::current();
if (!thread.is_initialized()) {
- Processor::init_context(thread);
+ proc.init_context(thread, false);
thread.set_initialized(true);
}
thread.set_state(Thread::Running);
- Processor::current().switch_context(current_thread, &thread);
+ proc.switch_context(current_thread, &thread);
return true;
}
diff --git a/Kernel/SpinLock.h b/Kernel/SpinLock.h
index e0855a0790..a62b2519bc 100644
--- a/Kernel/SpinLock.h
+++ b/Kernel/SpinLock.h
@@ -43,19 +43,23 @@ public:
SpinLock(const SpinLock&) = delete;
SpinLock(SpinLock&&) = delete;
- ALWAYS_INLINE void lock()
+ ALWAYS_INLINE u32 lock()
{
+ u32 prev_flags;
+ Processor::current().enter_critical(prev_flags);
BaseType expected;
do {
expected = 0;
} while (!m_lock.compare_exchange_strong(expected, 1, AK::memory_order_acq_rel));
+ return prev_flags;
}
- ALWAYS_INLINE void unlock()
+ ALWAYS_INLINE void unlock(u32 prev_flags)
{
ASSERT(is_locked());
m_lock.store(0, AK::memory_order_release);
+ Processor::current().leave_critical(prev_flags);
}
ALWAYS_INLINE bool is_locked() const
@@ -79,9 +83,12 @@ public:
RecursiveSpinLock(const RecursiveSpinLock&) = delete;
RecursiveSpinLock(RecursiveSpinLock&&) = delete;
- ALWAYS_INLINE void lock()
+ ALWAYS_INLINE u32 lock()
{
- FlatPtr cpu = FlatPtr(&Processor::current());
+ auto& proc = Processor::current();
+ FlatPtr cpu = FlatPtr(&proc);
+ u32 prev_flags;
+ proc.enter_critical(prev_flags);
FlatPtr expected = 0;
while (!m_lock.compare_exchange_strong(expected, cpu, AK::memory_order_acq_rel)) {
if (expected == cpu)
@@ -89,14 +96,16 @@ public:
expected = 0;
}
m_recursions++;
+ return prev_flags;
}
- ALWAYS_INLINE void unlock()
+ ALWAYS_INLINE void unlock(u32 prev_flags)
{
ASSERT(m_recursions > 0);
ASSERT(m_lock.load(AK::memory_order_consume) == FlatPtr(&Processor::current()));
if (--m_recursions == 0)
m_lock.store(0, AK::memory_order_release);
+ Processor::current().leave_critical(prev_flags);
}
ALWAYS_INLINE bool is_locked() const
@@ -114,8 +123,8 @@ template <typename BaseType = u32, typename LockType = SpinLock<BaseType>>
class ScopedSpinLock
{
LockType* m_lock;
+ u32 m_prev_flags{0};
bool m_have_lock{false};
- bool m_flag{false};
public:
ScopedSpinLock() = delete;
@@ -124,19 +133,18 @@ public:
m_lock(&lock)
{
ASSERT(m_lock);
- m_flag = cli_and_save_interrupt_flag();
- m_lock->lock();
+ m_prev_flags = m_lock->lock();
m_have_lock = true;
}
ScopedSpinLock(ScopedSpinLock&& from):
m_lock(from.m_lock),
- m_have_lock(from.m_have_lock),
- m_flag(from.m_flag)
+ m_prev_flags(from.m_prev_flags),
+ m_have_lock(from.m_have_lock)
{
from.m_lock = nullptr;
+ from.m_prev_flags = 0;
from.m_have_lock = false;
- from.m_flag = false;
}
ScopedSpinLock(const ScopedSpinLock&) = delete;
@@ -144,8 +152,7 @@ public:
~ScopedSpinLock()
{
if (m_lock && m_have_lock) {
- m_lock->unlock();
- restore_interrupt_flag(m_flag);
+ m_lock->unlock(m_prev_flags);
}
}
@@ -153,8 +160,7 @@ public:
{
ASSERT(m_lock);
ASSERT(!m_have_lock);
- m_flag = cli_and_save_interrupt_flag();
- m_lock->lock();
+ m_prev_flags = m_lock->lock();
m_have_lock = true;
}
@@ -162,10 +168,9 @@ public:
{
ASSERT(m_lock);
ASSERT(m_have_lock);
- m_lock->unlock();
+ m_lock->unlock(m_prev_flags);
+ m_prev_flags = 0;
m_have_lock = false;
- restore_interrupt_flag(m_flag);
- m_flag = false;
}
ALWAYS_INLINE bool have_lock() const
diff --git a/Kernel/Thread.cpp b/Kernel/Thread.cpp
index 9dcb8964b6..532346f472 100644
--- a/Kernel/Thread.cpp
+++ b/Kernel/Thread.cpp
@@ -181,7 +181,8 @@ void Thread::die_if_needed()
if (!m_should_die)
return;
- unlock_process_if_locked();
+ u32 prev_crit;
+ unlock_process_if_locked(prev_crit);
InterruptDisabler disabler;
set_state(Thread::State::Dying);
@@ -190,20 +191,26 @@ void Thread::die_if_needed()
void Thread::yield_without_holding_big_lock()
{
- bool did_unlock = unlock_process_if_locked();
+ u32 prev_crit;
+ bool did_unlock = unlock_process_if_locked(prev_crit);
Scheduler::yield();
- if (did_unlock)
- relock_process();
+ relock_process(did_unlock, prev_crit);
}
-bool Thread::unlock_process_if_locked()
+bool Thread::unlock_process_if_locked(u32& prev_crit)
{
+ auto& in_critical = Processor::current().in_critical();
+ prev_crit = in_critical;
+ in_critical = 0;
return process().big_lock().force_unlock_if_locked();
}
-void Thread::relock_process()
+void Thread::relock_process(bool did_unlock, u32 prev_crit)
{
- process().big_lock().lock();
+ if (did_unlock)
+ process().big_lock().lock();
+ ASSERT(!Processor::current().in_critical());
+ Processor::current().in_critical() = prev_crit;
}
u64 Thread::sleep(u32 ticks)
@@ -328,6 +335,7 @@ void Thread::send_signal(u8 signal, [[maybe_unused]] Process* sender)
dbg() << "Signal: Kernel sent " << signal << " to " << process();
#endif
+ ScopedSpinLock lock(g_scheduler_lock);
m_pending_signals |= 1 << (signal - 1);
}
@@ -339,13 +347,10 @@ void Thread::send_signal(u8 signal, [[maybe_unused]] Process* sender)
// the appropriate signal handler.
void Thread::send_urgent_signal_to_self(u8 signal)
{
- // FIXME: because of a bug in dispatch_signal we can't
- // setup a signal while we are the current thread. Because of
- // this we use a work-around where we send the signal and then
- // block, allowing the scheduler to properly dispatch the signal
- // before the thread is next run.
- send_signal(signal, &process());
- (void)block<SemiPermanentBlocker>(SemiPermanentBlocker::Reason::Signal);
+ ASSERT(Thread::current() == this);
+ ScopedSpinLock lock(g_scheduler_lock);
+ if (dispatch_signal(signal) == ShouldUnblockThread::No)
+ Scheduler::yield();
}
ShouldUnblockThread Thread::dispatch_one_pending_signal()
@@ -443,6 +448,7 @@ static void push_value_on_user_stack(u32* stack, u32 data)
ShouldUnblockThread Thread::dispatch_signal(u8 signal)
{
ASSERT_INTERRUPTS_DISABLED();
+ ASSERT(g_scheduler_lock.is_locked());
ASSERT(signal > 0 && signal <= 32);
ASSERT(!process().is_ring0());
@@ -540,6 +546,10 @@ ShouldUnblockThread Thread::dispatch_signal(u8 signal)
u32 ret_eip = state.eip;
u32 ret_eflags = state.eflags;
+#ifdef SIGNAL_DEBUG
+ klog() << "signal: setting up user stack to return to eip: " << String::format("%p", ret_eip) << " esp: " << String::format("%p", old_esp);
+#endif
+
// Align the stack to 16 bytes.
// Note that we push 56 bytes (4 * 14) on to the stack,
// so we need to account for this here.
@@ -698,7 +708,7 @@ bool Thread::is_thread(void* ptr)
void Thread::set_state(State new_state)
{
- InterruptDisabler disabler;
+ ScopedSpinLock lock(g_scheduler_lock);
if (new_state == m_state)
return;
@@ -712,6 +722,9 @@ void Thread::set_state(State new_state)
}
m_state = new_state;
+#ifdef THREAD_DEBUG
+ dbg() << "Set Thread " << VirtualAddress(this) << " " << *this << " state to " << state_string();
+#endif
if (m_process.pid() != 0) {
Scheduler::update_state_for_thread(*this);
}
@@ -842,11 +855,12 @@ const LogStream& operator<<(const LogStream& stream, const Thread& value)
Thread::BlockResult Thread::wait_on(WaitQueue& queue, timeval* timeout, Atomic<bool>* lock, Thread* beneficiary, const char* reason)
{
TimerId timer_id {};
+ u32 prev_crit;
bool did_unlock;
{
InterruptDisabler disable;
- did_unlock = unlock_process_if_locked();
+ did_unlock = unlock_process_if_locked(prev_crit);
if (lock)
*lock = false;
set_state(State::Queued);
@@ -870,8 +884,7 @@ Thread::BlockResult Thread::wait_on(WaitQueue& queue, timeval* timeout, Atomic<b
sti();
// We've unblocked, relock the process if needed and carry on.
- if (did_unlock)
- relock_process();
+ relock_process(did_unlock, prev_crit);
BlockResult result = m_wait_queue_node.is_in_list() ? BlockResult::InterruptedByTimeout : BlockResult::WokeNormally;
@@ -884,6 +897,7 @@ Thread::BlockResult Thread::wait_on(WaitQueue& queue, timeval* timeout, Atomic<b
void Thread::wake_from_queue()
{
+ ScopedSpinLock lock(g_scheduler_lock);
ASSERT(state() == State::Queued);
if (this != Thread::current())
set_state(State::Runnable);
diff --git a/Kernel/Thread.h b/Kernel/Thread.h
index 4ad06d49fa..5bac56e195 100644
--- a/Kernel/Thread.h
+++ b/Kernel/Thread.h
@@ -463,8 +463,8 @@ private:
private:
friend class SchedulerData;
friend class WaitQueue;
- bool unlock_process_if_locked();
- void relock_process();
+ bool unlock_process_if_locked(u32& prev_crit);
+ void relock_process(bool did_unlock, u32 prev_crit);
String backtrace_impl() const;
void reset_fpu_state();
diff --git a/Kernel/VM/MemoryManager.cpp b/Kernel/VM/MemoryManager.cpp
index b43bd9c0f5..eefa569f3b 100644
--- a/Kernel/VM/MemoryManager.cpp
+++ b/Kernel/VM/MemoryManager.cpp
@@ -591,7 +591,7 @@ u8* MemoryManager::quickmap_page(PhysicalPage& physical_page)
{
ASSERT_INTERRUPTS_DISABLED();
auto& mm_data = get_data();
- mm_data.m_quickmap_in_use.lock();
+ mm_data.m_quickmap_prev_flags = mm_data.m_quickmap_in_use.lock();
ScopedSpinLock lock(s_lock);
u32 pte_idx = 8 + Processor::current().id();
@@ -622,7 +622,7 @@ void MemoryManager::unquickmap_page()
auto& pte = boot_pd3_pt1023[pte_idx];
pte.clear();
flush_tlb(vaddr);
- mm_data.m_quickmap_in_use.unlock();
+ mm_data.m_quickmap_in_use.unlock(mm_data.m_quickmap_prev_flags);
}
template<MemoryManager::AccessSpace space, MemoryManager::AccessType access_type>
@@ -736,6 +736,7 @@ void MemoryManager::dump_kernel_regions()
{
klog() << "Kernel regions:";
klog() << "BEGIN END SIZE ACCESS NAME";
+ ScopedSpinLock lock(s_lock);
for (auto& region : MM.m_kernel_regions) {
klog() << String::format("%08x", region.vaddr().get()) << " -- " << String::format("%08x", region.vaddr().offset(region.size() - 1).get()) << " " << String::format("%08x", region.size()) << " " << (region.is_readable() ? 'R' : ' ') << (region.is_writable() ? 'W' : ' ') << (region.is_executable() ? 'X' : ' ') << (region.is_shared() ? 'S' : ' ') << (region.is_stack() ? 'T' : ' ') << (region.vmobject().is_purgeable() ? 'P' : ' ') << " " << region.name().characters();
}
diff --git a/Kernel/VM/MemoryManager.h b/Kernel/VM/MemoryManager.h
index c9e72fd1bc..f176424182 100644
--- a/Kernel/VM/MemoryManager.h
+++ b/Kernel/VM/MemoryManager.h
@@ -69,6 +69,7 @@ class SynthFSInode;
struct MemoryManagerData {
SpinLock<u8> m_quickmap_in_use;
+ u32 m_quickmap_prev_flags;
};
class MemoryManager {
diff --git a/Kernel/WaitQueue.cpp b/Kernel/WaitQueue.cpp
index b5d5d759dd..c5122f64f3 100644
--- a/Kernel/WaitQueue.cpp
+++ b/Kernel/WaitQueue.cpp
@@ -39,13 +39,13 @@ WaitQueue::~WaitQueue()
void WaitQueue::enqueue(Thread& thread)
{
- InterruptDisabler disabler;
+ ScopedCritical critical;
m_threads.append(thread);
}
void WaitQueue::wake_one(Atomic<bool>* lock)
{
- InterruptDisabler disabler;
+ ScopedCritical critical;
if (lock)
*lock = false;
if (m_threads.is_empty())
@@ -57,7 +57,7 @@ void WaitQueue::wake_one(Atomic<bool>* lock)
void WaitQueue::wake_n(i32 wake_count)
{
- InterruptDisabler disabler;
+ ScopedCritical critical;
if (m_threads.is_empty())
return;
@@ -72,7 +72,7 @@ void WaitQueue::wake_n(i32 wake_count)
void WaitQueue::wake_all()
{
- InterruptDisabler disabler;
+ ScopedCritical critical;
if (m_threads.is_empty())
return;
while (!m_threads.is_empty())
@@ -82,7 +82,7 @@ void WaitQueue::wake_all()
void WaitQueue::clear()
{
- InterruptDisabler disabler;
+ ScopedCritical critical;
m_threads.clear();
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 00:17:41 +0000