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Way tighter locking in process creation.

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We no longer disable interrupts around the whole affair.
Since MM manages per-process data structures, this works quite smoothly now.
Only procfs had to be tweaked with an InterruptDisabler.
This commit is contained in:
Andreas Kling 2018-11-01 14:41:49 +01:00
parent 52607aa086
commit 3a901ae36d
3 changed files with 40 additions and 25 deletions
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4
Kernel/ProcFileSystem.cpp
View file

@ -116,7 +116,7 @@ ByteBuffer procfs$pid_exe(Process& process)
void ProcFileSystem::addProcess(Process& process)
{
ASSERT_INTERRUPTS_DISABLED();
InterruptDisabler disabler;
char buf[16];
ksprintf(buf, "%d", process.pid());
auto dir = addFile(createDirectory(buf));
@ -130,7 +130,7 @@ void ProcFileSystem::addProcess(Process& process)
void ProcFileSystem::removeProcess(Process& process)
{
ASSERT_INTERRUPTS_DISABLED();
InterruptDisabler disabler;
auto pid = process.pid();
auto it = m_pid2inode.find(pid);
ASSERT(it != m_pid2inode.end());

24
Kernel/Process.cpp
View file

@ -86,13 +86,20 @@ void Process::prepForIRETToNewProcess()
loadTaskRegister(s_kernelProcess->selector());
}
static void hlt_loop()
{
for (;;) {
asm volatile("hlt");
}
}
void Process::initialize()
{
current = nullptr;
next_pid = 0;
s_processes = new InlineLinkedList<Process>;
s_deadProcesses = new InlineLinkedList<Process>;
s_kernelProcess = Process::createKernelProcess(nullptr, "colonel");
s_kernelProcess = Process::createKernelProcess(hlt_loop, "colonel");
s_hostname = new String("birx");
redoKernelProcessTSS();
loadTaskRegister(s_kernelProcess->selector());
@ -271,18 +278,16 @@ Process* Process::createUserProcess(const String& path, uid_t uid, gid_t gid, pi
processEnvironment.append("TERM=console");
processEnvironment.append("HOME=/");
InterruptDisabler disabler; // FIXME: Get rid of this, jesus christ. This "critical" section is HUGE.
KernelPagingScope pagingScope;
Process* t = new Process(parts.takeLast(), uid, gid, parentPID, Ring3, move(cwd), handle->vnode(), tty);
auto* t = new Process(parts.takeLast(), uid, gid, parentPID, Ring3, move(cwd), handle->vnode(), tty);
t->m_arguments = move(processArguments);
t->m_initialEnvironment = move(processEnvironment);
ExecSpace space;
Region* region = nullptr;
byte* region_alias = nullptr;
KernelPagingScope pagingScope;
space.hookableAlloc = [&] (const String& name, size_t size) {
if (!size)
return (void*)nullptr;
@ -330,6 +335,8 @@ Process* Process::createUserProcess(const String& path, uid_t uid, gid_t gid, pi
ASSERT(region);
MM.remove_kernel_alias_for_region(*region, region_alias);
ProcFileSystem::the().addProcess(*t);
s_processes->prepend(t);
system.nprocess++;
#ifdef TASK_DEBUG
@ -379,13 +386,14 @@ int Process::sys$get_arguments(int* argc, char*** argv)
Process* Process::createKernelProcess(void (*e)(), String&& name)
{
Process* process = new Process(move(name), (uid_t)0, (gid_t)0, (pid_t)0, Ring0);
auto* process = new Process(move(name), (uid_t)0, (gid_t)0, (pid_t)0, Ring0);
process->m_tss.eip = (dword)e;
if (process->pid() != 0) {
InterruptDisabler disabler;
s_processes->prepend(process);
system.nprocess++;
ProcFileSystem::the().addProcess(*process);
#ifdef TASK_DEBUG
kprintf("Kernel process %u (%s) spawned @ %p\n", process->pid(), process->name().characters(), process->m_tss.eip);
#endif
@ -474,8 +482,6 @@ Process::Process(String&& name, uid_t uid, gid_t gid, pid_t parentPID, RingLevel
// HACK: Ring2 SS in the TSS is the current PID.
m_tss.ss2 = m_pid;
m_farPtr.offset = 0x98765432;
ProcFileSystem::the().addProcess(*this);
}
Process::~Process()
@ -707,7 +713,7 @@ bool scheduleNewProcess()
process->timesScheduled(),
process->name().characters());
}
kprintf("Switch to kernel process\n");
kprintf("Switch to kernel process @ %w:%x\n", s_kernelProcess->tss().cs, s_kernelProcess->tss().eip);
return contextSwitch(Process::kernelProcess());
}
}

37
Kernel/init.cpp
View file

@ -101,6 +101,25 @@ static void undertaker_main()
}
}
static void spawn_stress() NORETURN;
static void spawn_stress()
{
dword lastAlloc = sum_alloc;
for (unsigned i = 0; i < 100; ++i) {
int error;
Process::createUserProcess("/bin/id", (uid_t)100, (gid_t)100, (pid_t)0, error, nullptr, tty0);
kprintf("malloc stats: alloc:%u free:%u\n", sum_alloc, sum_free);
kprintf("delta:%u\n", sum_alloc - lastAlloc);
lastAlloc = sum_alloc;
sleep(600);
}
for (;;) {
asm volatile("hlt");
}
}
static void init_stage2() NORETURN;
static void init_stage2()
{
@ -173,20 +192,6 @@ static void init_stage2()
}
#endif
#ifdef STRESS_TEST_SPAWNING
dword lastAlloc = sum_alloc;
for (unsigned i = 0; i < 100; ++i) {
int error;
auto* shProcess = Process::createUserProcess("/bin/id", (uid_t)100, (gid_t)100, (pid_t)0, error);
kprintf("malloc stats: alloc:%u free:%u\n", sum_alloc, sum_free);
kprintf("sizeof(Process):%u\n", sizeof(Process));
kprintf("delta:%u\n",sum_alloc - lastAlloc);
lastAlloc = sum_alloc;
sleep(600);
}
#endif
int error;
auto* sh0 = Process::createUserProcess("/bin/sh", (uid_t)100, (gid_t)100, (pid_t)0, error, nullptr, tty0);
#ifdef SPAWN_MULTIPLE_SHELLS
@ -195,6 +200,10 @@ static void init_stage2()
auto* sh3 = Process::createUserProcess("/bin/sh", (uid_t)100, (gid_t)100, (pid_t)0, error, nullptr, tty3);
#endif
#ifdef STRESS_TEST_SPAWNING
Process::createKernelProcess(spawn_stress, "spawn_stress");
#endif
#if 0
// It would be nice to exit this process, but right now it instantiates all kinds of things.
// At the very least it needs to be made sure those things stick around as appropriate.