syscalls: sync

kernel-src/arch/x86-64/isr.asm

@@ -48,6 +48,7 @@ isr_%+ i:
 	cld
 	extern interrupt_isr
 	call interrupt_isr
+	cli
 
 	; pop context
 	add rsp, 24 ; cr2 gs and fs are not popped.

kernel-src/arch/x86-64/syscall.asm

@@ -64,6 +64,7 @@ extern syscall_kill
 extern syscall_sigreturn
 extern syscall_uname
 extern syscall_hostname
+extern syscall_sync
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -130,7 +131,8 @@ dq syscall_kill
 dq syscall_sigreturn
 dq syscall_uname
 dq syscall_hostname
-syscallcount equ 65
+dq syscall_sync
+syscallcount equ 66
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/arch/x86-64/syscalllog.c

@@ -4,7 +4,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 65
+#define SYSCALL_COUNT 66
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -72,7 +72,8 @@ static char *name[] = {
 	"kill",
 	"sigreturn",
 	"uname",
-	"hostname"
+	"hostname",
+	"sync"
 };
 
 static char *args[] = {
@@ -140,7 +141,8 @@ static char *args[] = {
 	"pid %d signal %d", // kill
 	"N/A", // sigreturn
 	"utsname %p", // uname
-	"new %p newsize %lu old %p oldsize %lu" // hostname
+	"new %p newsize %lu old %p oldsize %lu", // hostname
+	"N/A" // sync
 };
 
 #endif

kernel-src/mm/vmmcache.c

@@ -2,6 +2,7 @@
 #include <kernel/vmm.h>
 #include <util.h>
 #include <logging.h>
+#include <kernel/poll.h>
 
 #define TABLE_SIZE 4096
 #define WRITER_TICK_SECONDS 1
@@ -11,6 +12,7 @@ static page_t **table;
 
 static thread_t *writerthread;
 static semaphore_t sync;
+static pollheader_t syncpollheader;
 
 #define HOLD_LOCK() \
 	MUTEX_ACQUIRE(&mutex, false);
@@ -234,12 +236,39 @@ int vmmcache_syncvnode(vnode_t *vnode) {
 	__assert(!"unimplemented");
 }
 
+static page_t *dirtylist;
+
 int vmmcache_sync() {
-	semaphore_signal(&sync);
+	polldesc_t polldesc = {0};
+	int e = poll_initdesc(&polldesc, 1);
+	HOLD_LOCK();
+	if (dirtylist == NULL) {
+		// no dirty pages
+		RELEASE_LOCK();
+		if (e == 0)
+			goto leave;
+
 		return 0;
+	} else if (e) {
+		// there are dirty pages but poll alloc failed,
+		// tell the thread to do its thing but don't wait
+		RELEASE_LOCK();
+		printf("vmmcache: sync not waiting because of a poll allocation failure\n");
+		semaphore_signal(&sync);
+		return e;
 	}
 
-static page_t *dirtylist;
+	poll_add(&syncpollheader, &polldesc.data[0], POLLPRI);
+	semaphore_signal(&sync);
+	RELEASE_LOCK();
+
+	e = poll_dowait(&polldesc, 0);
+
+	leave:
+	poll_leave(&polldesc);
+	poll_destroydesc(&polldesc);
+	return e;
+}
 
 int vmmcache_makedirty(page_t *page) {
 	HOLD_LOCK();
@@ -264,7 +293,7 @@ int vmmcache_makedirty(page_t *page) {
 }
 
 static void tick(context_t *, dpcarg_t arg) {
-	vmmcache_sync();
+	semaphore_signal(&sync);
 }
 
 static void writer() {
@@ -278,6 +307,7 @@ static void writer() {
 		// TODO make FIFO rather than LIFO
 		volatile page_t *page = dirtylist;
 		if (page == NULL) {
+			poll_event(&syncpollheader, POLLPRI);
 			RELEASE_LOCK();
 			semaphore_wait(&sync, false);
 			continue;
@@ -313,4 +343,5 @@ void vmmcache_init() {
 	__assert(writerthread);
 	sched_queue(writerthread);
 	vmmcache_sync();
+	POLL_INITHEADER(&syncpollheader);
 }

kernel-src/sys/syscalls/sync.c

@@ -0,0 +1,8 @@
+#include <kernel/syscalls.h>
+#include <kernel/vmmcache.h>
+
+syscallret_t syscall_sync(context_t *) {
+	syscallret_t ret = {0};
+	vmmcache_sync();
+	return ret;
+}

patches/mlibc/jinx-working-patch.patch

@@ -192,10 +192,10 @@ index 0000000..e5b087a
 +
 diff --git mlibc-workdir/sysdeps/astral/generic/generic.cpp mlibc-workdir/sysdeps/astral/generic/generic.cpp
 new file mode 100644
-index 0000000..c409d89
+index 0000000..12da52c
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/generic/generic.cpp
-@@ -0,0 +1,690 @@
+@@ -0,0 +1,695 @@
 +#include <bits/ensure.h>
 +#include <mlibc/debug.hpp>
 +#include <mlibc/all-sysdeps.hpp>
@@ -315,6 +315,11 @@ index 0000000..c409d89
 +		return syscall(SYSCALL_UNAME, &ret, (uint64_t)buf);
 +	}
 +
++	void sys_sync() {
++		long ret;
++		syscall(SYSCALL_SYNC, &ret);
++	}
++
 +	int sys_fsync(int fd) {
 +		// TODO as the VFS does not do caching as of yet, this system call is stubbed and should be implemented once caching is done
 +		return 0;
@@ -905,10 +910,10 @@ index 0000000..990eca0
 +#endif
 diff --git mlibc-workdir/sysdeps/astral/include/astral/syscall.h mlibc-workdir/sysdeps/astral/include/astral/syscall.h
 new file mode 100644
-index 0000000..3a130be
+index 0000000..7daaf11
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-@@ -0,0 +1,88 @@
+@@ -0,0 +1,89 @@
 +#ifndef _SYSCALL_H_INCLUDE
 +#define _SYSCALL_H_INCLUDE
 +
@@ -977,6 +982,7 @@ index 0000000..3a130be
 +#define SYSCALL_SIGRETURN 62
 +#define SYSCALL_UNAME 63
 +#define SYSCALL_HOSTNAME 64
++#define SYSCALL_SYNC 65
 +
 +#include <stddef.h>
 +#include <stdint.h>