bootstrap::xorg: fix deadlocks

* Vm::handle_page_fault: lock IRQ since threads share the same VM and
can be a case where the lock is held and a reschedule interrupt occured.
* syscall::time: For monotonic, currently just return the realtime value
(in-order to make Xorg function).
* Pipe::write_at: lock IRQ
* Pipe::poll: initial implmentation and lock IRQ there aswell
* epoll: remove unused import
* time: `REALTIME_CLOCK` lock IRQ
* xorg: use poll instead of epoll for now
* xorg: compile with debug symbols

fun! :^)
Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>

Author: Andy-Python-Programmer

bootstrap/xorg.yml

@@ -669,7 +669,7 @@ packages:
         - '--disable-glamor'
         - '--disable-glx'
         environ:
-          CFLAGS: '-Wno-error=array-bounds -O2 -pipe'
+          CFLAGS: '-Wno-error=array-bounds -O0 -g -pipe'
     build:
       - args: ['make', '-j@PARALLELISM@']
       - args: ['make', 'install-strip']

patches/xorg-server/0001-xserver-aero-specific-changes.patch

@@ -1,4 +1,4 @@
-From 3d08eb0ba228adf632f38c0c8f6476c1d0342386 Mon Sep 17 00:00:00 2001
+From 6a1cb57184179a2971bedd477fa71f30bbac6a09 Mon Sep 17 00:00:00 2001
 From: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
 Date: Thu, 30 Jun 2022 11:10:21 +1000
 Subject: [PATCH] xserver: aero specific changes
@@ -20,8 +20,9 @@ Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
  include/os.h                             |  1 +
  mi/mibitblt.c                            |  2 ++
  os/access.c                              |  2 +-
+ os/ospoll.c                              |  2 ++
  os/utils.c                               |  6 ++--
- 16 files changed, 50 insertions(+), 20 deletions(-)
+ 17 files changed, 52 insertions(+), 20 deletions(-)
 
 diff --git a/.gitignore b/.gitignore
 index dc56b46..81d9886 100644
@@ -327,6 +328,24 @@ index 9724616..81befe3 100644
  #include <sys/utsname.h>
  #endif
  #if defined(SYSV) &&  defined(__i386__)
+diff --git a/os/ospoll.c b/os/ospoll.c
+index c68aabc..19006c3 100644
+--- a/os/ospoll.c
++++ b/os/ospoll.c
+@@ -45,11 +45,13 @@
+ #define HAVE_OSPOLL     1
+ #endif
+ 
++#if 0
+ #if !HAVE_OSPOLL && defined(HAVE_EPOLL_CREATE1)
+ #include <sys/epoll.h>
+ #define EPOLL           1
+ #define HAVE_OSPOLL     1
+ #endif
++#endif
+ 
+ #if !HAVE_OSPOLL
+ #include "xserver_poll.h"
 diff --git a/os/utils.c b/os/utils.c
 index 2ba1c80..ffa961f 100644
 --- a/os/utils.c

src/aero_kernel/src/fs/epoll.rs

@@ -23,7 +23,6 @@ use aero_syscall::SyscallError;
 use alloc::sync::Arc;
 use hashbrown::HashMap;
 
-use crate::fs::cache::DirCacheImpl;
 use crate::userland::scheduler;
 use crate::utils::sync::Mutex;
 

src/aero_kernel/src/fs/pipe.rs

@@ -5,7 +5,7 @@ use alloc::{sync::Arc, vec::Vec};
 
 use crate::utils::sync::{BlockQueue, Mutex};
 
-use super::inode::INodeInterface;
+use super::inode::{INodeInterface, PollFlags, PollTable};
 
 struct Buffer {
     data: Vec<u8>,
@@ -82,9 +82,10 @@ impl INodeInterface for Pipe {
     fn close(&self, flags: OpenFlags) {
         // Write end of the pipe:
         if flags.contains(OpenFlags::O_WRONLY) {
-            let active_writers = (self.num_writers.fetch_sub(1, Ordering::SeqCst) - 1) == 0;
+            let active_writers = self.num_writers.fetch_sub(1, Ordering::SeqCst) - 1;
+
             // There are no active writers and no data to read (reached EOF).
-            if active_writers {
+            if active_writers == 0 {
                 self.readers.notify_complete();
             }
         }
@@ -106,9 +107,24 @@ impl INodeInterface for Pipe {
     }
 
     fn write_at(&self, offset: usize, buf: &[u8]) -> super::Result<usize> {
-        let res = offset + self.queue.lock().write_data(buf);
+        let res = offset + self.queue.lock_irq().write_data(buf);
         self.readers.notify_complete();
 
         Ok(res)
     }
+
+    fn poll(&self, table: Option<&mut PollTable>) -> super::Result<PollFlags> {
+        table.map(|e| {
+            e.insert(&self.readers);
+            e.insert(&self.writers)
+        });
+
+        let mut flags = PollFlags::OUT;
+
+        if self.queue.lock_irq().has_data() {
+            flags |= PollFlags::IN;
+        }
+
+        Ok(flags)
+    }
 }

src/aero_kernel/src/syscall/fs.rs

@@ -589,24 +589,6 @@ pub fn poll(
         return Ok(n);
     }
 
-    'search: loop {
-        // Wait till one of the file descriptor deliever an event.
-        scheduler::get_scheduler().inner.await_io()?;
-
-        for (handle, index) in refds.iter() {
-            let pollfd = &mut fds[*index];
-            let ready: PollEventFlags = handle.inode().poll(None)?.into();
-
-            if ready.contains(pollfd.events) {
-                // The event is ready; break out of the search loop and set ready
-                // events to 1.
-                pollfd.revents = ready & pollfd.events;
-                n = 1;
-                break 'search;
-            }
-        }
-    }
-
     // Restore the orignal signal mask.
     signals.set_mask(SigProcMask::Set, Some(old_mask), None);
     Ok(n)

src/aero_kernel/src/syscall/time.rs

@@ -47,7 +47,12 @@ pub fn gettime(clock: usize, timespec: &mut TimeSpec) -> Result<usize, SyscallEr
         }
 
         CLOCK_TYPE_MONOTONIC => {
-            log::debug!("monotonic");
+            // FIXME: implement
+            let clock = crate::time::get_realtime_clock();
+
+            timespec.tv_sec = clock.tv_sec;
+            timespec.tv_nsec = clock.tv_nsec;
+
             Ok(0x00)
         }
 

src/aero_kernel/src/time.rs

@@ -53,7 +53,7 @@ pub fn get_uptime_ticks() -> usize {
 }
 
 pub fn get_realtime_clock() -> TimeSpec {
-    REALTIME_CLOCK.lock().clone()
+    REALTIME_CLOCK.lock_irq().clone()
 }
 
 /// Returns the current amount of PIT ticks.
@@ -94,7 +94,7 @@ fn pit_irq_handler(_stack: &mut InterruptStack) {
             tv_nsec: (1000000000 / PIT_FREQUENCY_HZ) as isize,
         };
 
-        let mut this = REALTIME_CLOCK.lock();
+        let mut this = REALTIME_CLOCK.lock_irq();
 
         if this.tv_nsec + interval.tv_nsec > 999999999 {
             let diff = (this.tv_nsec + interval.tv_nsec) - 1000000000;

src/aero_kernel/src/userland/vm.rs

@@ -1149,7 +1149,7 @@ impl Vm {
         accessed_address: VirtAddr,
     ) -> bool {
         self.inner
-            .lock()
+            .lock_irq()
             .handle_page_fault(reason, accessed_address)
     }