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-rw-r--r--src/init/syscalls.c4
-rw-r--r--src/init/tests/pipe.c61
-rw-r--r--src/kernel/handle.c7
-rw-r--r--src/kernel/handle.h4
-rw-r--r--src/kernel/pipe.c39
-rw-r--r--src/kernel/pipe.h6
-rw-r--r--src/kernel/syscalls.c39
-rw-r--r--src/shared/syscalls.h2
8 files changed, 124 insertions, 38 deletions
diff --git a/src/init/syscalls.c b/src/init/syscalls.c
index 14c0d52..25fa134 100644
--- a/src/init/syscalls.c
+++ b/src/init/syscalls.c
@@ -50,8 +50,8 @@ void __user *_syscall_memflag(void __user *addr, size_t len, int flags) {
return (void __user *)_syscall(_SYSCALL_MEMFLAG, (int)addr, (int)len, flags, 0);
}
-handle_t _syscall_pipe(int flags) {
- return (handle_t)_syscall(_SYSCALL_PIPE, flags, 0, 0, 0);
+int _syscall_pipe(handle_t __user user_ends[2], int flags) {
+ return _syscall(_SYSCALL_PIPE, (int)user_ends, flags, 0, 0);
}
void _syscall_debug_klog(const void __user *buf, size_t len) {
diff --git a/src/init/tests/pipe.c b/src/init/tests/pipe.c
index bbfe79a..697b9b1 100644
--- a/src/init/tests/pipe.c
+++ b/src/init/tests/pipe.c
@@ -6,36 +6,75 @@
static const char *pipe_msgs[2] = {"hello", "world"};
-static void test_pipe_child(handle_t pipe) {
- int ret = _syscall_write(pipe, pipe_msgs[0], 5, -1);
+static void test_pipe_child(handle_t ends[2]) {
+ int ret = _syscall_write(ends[1], pipe_msgs[0], 5, -1);
assert(ret == 5);
- ret = _syscall_write(pipe, pipe_msgs[1], 5, -1);
+ ret = _syscall_write(ends[1], pipe_msgs[1], 5, -1);
assert(ret == 5);
}
-static void test_pipe_parent(handle_t pipe) {
+static void test_pipe_parent(handle_t ends[2]) {
char buf[16];
- int ret = _syscall_read(pipe, buf, 16, 0);
+ int ret = _syscall_read(ends[0], buf, 16, 0);
assert(ret == 5);
assert(!memcmp(buf, pipe_msgs[0], 5));
- _syscall_read(pipe, buf, 16, 0);
+ _syscall_read(ends[0], buf, 16, 0);
assert(ret == 5);
- assert(!memcmp(buf, pipe_msgs[1], 5)); // wrong compare for test
+ assert(!memcmp(buf, pipe_msgs[1], 5));
+
+ // TODO these calls fail for multiple reasons at once - split
+ assert(_syscall_read(ends[1], buf, 16, 0) < 0);
+ assert(_syscall_write(ends[0], buf, 16, 0) < 0);
}
void test_pipe(void) {
- handle_t pipe = _syscall_pipe(0);
- assert(pipe > 0);
+ handle_t ends[2];
+ char buf[16];
+ assert(_syscall_pipe(ends, 0) >= 0);
+
+ if (!_syscall_fork(0, NULL)) {
+ test_pipe_child(ends);
+ _syscall_exit(0);
+ } else {
+ test_pipe_parent(ends);
+ _syscall_await();
+ }
+
+ _syscall_close(ends[0]);
+ _syscall_close(ends[1]);
+
+ assert(_syscall_pipe(ends, 0) >= 0);
+ _syscall_close(ends[0]);
+ assert(_syscall_write(ends[1], buf, 16, 0) < 0);
+ _syscall_close(ends[1]);
+
+ assert(_syscall_pipe(ends, 0) >= 0);
+ _syscall_close(ends[1]);
+ assert(_syscall_read(ends[0], buf, 16, 0) < 0);
+ _syscall_close(ends[0]);
+
+
+ assert(_syscall_pipe(ends, 0) >= 0);
+ if (!_syscall_fork(0, NULL)) {
+ _syscall_exit(0);
+ } else {
+ _syscall_close(ends[1]);
+ assert(_syscall_read(ends[0], buf, 16, 0) < 0);
+ _syscall_await();
+ }
+ assert(_syscall_pipe(ends, 0) >= 0);
if (!_syscall_fork(0, NULL)) {
- test_pipe_child(pipe);
_syscall_exit(0);
} else {
- test_pipe_parent(pipe);
+ _syscall_close(ends[1]);
+ assert(_syscall_write(ends[1], buf, 16, 0) < 0);
_syscall_await();
}
+ // TODO detect when all processes that can read are stuck on writing to the pipe and vice verse
// TODO kill process that's waiting on a pipe
+ // TODO queue
}
diff --git a/src/kernel/handle.c b/src/kernel/handle.c
index 70830ff..ed7896d 100644
--- a/src/kernel/handle.c
+++ b/src/kernel/handle.c
@@ -1,6 +1,7 @@
#include <kernel/handle.h>
#include <kernel/mem/alloc.h>
#include <kernel/panic.h>
+#include <kernel/pipe.h>
#include <kernel/proc.h>
#include <kernel/vfs/request.h>
#include <shared/mem.h>
@@ -25,6 +26,12 @@ void handle_close(struct handle *h) {
.caller = NULL,
.backend = h->backend,
});
+ } else if (h->type == HANDLE_PIPE) {
+ assert(!h->pipe.queued);
+ if (h->pipe.sister) {
+ pipe_invalidate_end(h->pipe.sister);
+ h->pipe.sister->pipe.sister = NULL;
+ }
}
if (h->backend)
diff --git a/src/kernel/handle.h b/src/kernel/handle.h
index 4a5cab2..be8250b 100644
--- a/src/kernel/handle.h
+++ b/src/kernel/handle.h
@@ -18,7 +18,9 @@ struct handle {
struct vfs_backend *backend; // HANDLE_FILE | HANDLE_FS_FRONT
void __user *file_id; // only applicable to HANDLE_FILE
struct {
- struct process *reader, *writer;
+ struct process *queued;
+ bool write_end;
+ struct handle *sister; // the other end, not included in refcount
} pipe;
size_t refcount;
diff --git a/src/kernel/pipe.c b/src/kernel/pipe.c
index 8afd359..34cb263 100644
--- a/src/kernel/pipe.c
+++ b/src/kernel/pipe.c
@@ -3,29 +3,41 @@
#include <kernel/pipe.h>
#include <kernel/util.h>
-void pipe_joinqueue(struct handle *h, bool wants_write,
+bool pipe_joinqueue(struct handle *h, bool wants_write,
struct process *proc, void __user *pbuf, size_t pbuflen)
{
- struct process **slot = wants_write ? &h->pipe.reader : &h->pipe.writer;
- if (*slot) {
- assert((*slot)->state == PS_WAITS4PIPE);
+ assert(h && h->type == HANDLE_PIPE);
+ if (wants_write == h->pipe.write_end) return false;
+ if (!h->pipe.sister) return false;
+ if (h->pipe.queued) {
+ assert(h->pipe.queued->state == PS_WAITS4PIPE);
panic_unimplemented();
}
process_transition(proc, PS_WAITS4PIPE);
- *slot = proc;
+ h->pipe.queued = proc;
proc->waits4pipe.pipe = h;
proc->waits4pipe.buf = pbuf;
proc->waits4pipe.len = pbuflen;
+ return true;
}
void pipe_trytransfer(struct handle *h) {
- struct process *rdr = h->pipe.reader, *wtr = h->pipe.writer;
+ struct process *rdr, *wtr;
int len;
+ assert(h);
+ if (!h->pipe.sister) {
+ assert(!h->pipe.queued);
+ return;
+ }
+
+ rdr = h->pipe.write_end ? h->pipe.sister->pipe.queued : h->pipe.queued;
+ wtr = h->pipe.write_end ? h->pipe.queued : h->pipe.sister->pipe.queued;
+
if (!(rdr && wtr)) return;
assert(rdr->state == PS_WAITS4PIPE);
assert(wtr->state == PS_WAITS4PIPE);
-
+
len = min(rdr->waits4pipe.len, wtr->waits4pipe.len);
if (!virt_cpy(
@@ -36,8 +48,17 @@ void pipe_trytransfer(struct handle *h) {
}
process_transition(rdr, PS_RUNNING);
process_transition(wtr, PS_RUNNING);
- h->pipe.reader = NULL;
- h->pipe.writer = NULL;
+ h->pipe.queued = NULL;
+ h->pipe.sister->pipe.queued = NULL;
regs_savereturn(&rdr->regs, len);
regs_savereturn(&wtr->regs, len);
}
+
+void pipe_invalidate_end(struct handle *h) {
+ struct process *p = h->pipe.queued;
+ if (p) {
+ process_transition(p, PS_RUNNING);
+ regs_savereturn(&p->regs, -1);
+ }
+ h->pipe.queued = NULL;
+}
diff --git a/src/kernel/pipe.h b/src/kernel/pipe.h
index facaaaa..9040ab1 100644
--- a/src/kernel/pipe.h
+++ b/src/kernel/pipe.h
@@ -1,7 +1,11 @@
#pragma once
#include <kernel/proc.h>
+#include <stdbool.h>
-void pipe_joinqueue(struct handle *h, bool wants_write,
+/* returns false on failure */
+bool pipe_joinqueue(struct handle *h, bool wants_write,
struct process *proc, void __user *pbuf, size_t pbuflen);
void pipe_trytransfer(struct handle *h);
+
+void pipe_invalidate_end(struct handle *h);
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index c916e81..421b5ce 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -194,8 +194,10 @@ int _syscall_read(handle_t handle_num, void __user *buf, size_t len, int offset)
});
break;
case HANDLE_PIPE:
- pipe_joinqueue(h, true, process_current, buf, len);
- pipe_trytransfer(h);
+ if (pipe_joinqueue(h, true, process_current, buf, len))
+ pipe_trytransfer(h);
+ else
+ SYSCALL_RETURN(-1);
break;
default:
SYSCALL_RETURN(-1);
@@ -221,8 +223,10 @@ int _syscall_write(handle_t handle_num, const void __user *buf, size_t len, int
});
break;
case HANDLE_PIPE:
- pipe_joinqueue(h, false, process_current, (void __user *)buf, len);
- pipe_trytransfer(h);
+ if (pipe_joinqueue(h, false, process_current, (void __user *)buf, len))
+ pipe_trytransfer(h);
+ else
+ SYSCALL_RETURN(-1);
break;
default:
SYSCALL_RETURN(-1);
@@ -310,15 +314,24 @@ void __user *_syscall_memflag(void __user *addr, size_t len, int flags) {
SYSCALL_RETURN((uintptr_t)addr);
}
-handle_t _syscall_pipe(int flags) {
- if (flags) return -1;
+int _syscall_pipe(handle_t __user user_ends[2], int flags) {
+ if (flags) SYSCALL_RETURN(-1);
+ handle_t ends[2];
+ struct handle *rend, *wend;
- handle_t h = process_find_free_handle(process_current, 0);
- if (h < 0) return -1;
- process_current->handles[h] = handle_init(HANDLE_PIPE);
- assert(process_current->handles[h]->pipe.reader == NULL);
- assert(process_current->handles[h]->pipe.writer == NULL);
- SYSCALL_RETURN(h);
+ ends[0] = process_find_free_handle(process_current, 0);
+ if (ends[0] < 0) SYSCALL_RETURN(-1);
+ ends[1] = process_find_free_handle(process_current, ends[0]+1);
+ if (ends[1] < 0) SYSCALL_RETURN(-1);
+
+ rend = process_current->handles[ends[0]] = handle_init(HANDLE_PIPE);
+ wend = process_current->handles[ends[1]] = handle_init(HANDLE_PIPE);
+ wend->pipe.write_end = true;
+ wend->pipe.sister = rend;
+ rend->pipe.sister = wend;
+
+ virt_cpy_to(process_current->pages, user_ends, ends, sizeof ends);
+ SYSCALL_RETURN(0);
}
void _syscall_debug_klog(const void __user *buf, size_t len) {
@@ -366,7 +379,7 @@ int _syscall(int num, int a, int b, int c, int d) {
_syscall_memflag((userptr_t)a, b, c);
break;
case _SYSCALL_PIPE:
- _syscall_pipe(a);
+ _syscall_pipe((userptr_t)a, b);
break;
case _SYSCALL_DEBUG_KLOG:
_syscall_debug_klog((userptr_t)a, b);
diff --git a/src/shared/syscalls.h b/src/shared/syscalls.h
index c6d3c33..f19f05a 100644
--- a/src/shared/syscalls.h
+++ b/src/shared/syscalls.h
@@ -82,6 +82,6 @@ int _syscall_fs_respond(void __user *buf, int ret, int flags);
* @return address of the first affected page (usually == addr)
*/
void __user *_syscall_memflag(void __user *addr, size_t len, int flags);
-handle_t _syscall_pipe(int flags);
+int _syscall_pipe(handle_t __user user_ends[2], int flags);
void _syscall_debug_klog(const void __user *buf, size_t len);
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-22 18:11:19 +0000