intial working sys_spawn

9 files changed, 96 insertions, 23 deletions

diff --git a/include/kmi/regions.h b/include/kmi/regions.h
index 74d4387..fe263ae 100644
--- a/include/kmi/regions.h
+++ b/include/kmi/regions.h
@@ -236,6 +236,15 @@ struct mem_region *find_first_region(struct mem_region_root *r);
  */
 struct mem_region *find_used_region(struct mem_region_root *r, vm_t start);
 
+/**
+ * Find used memory region inside which \p addr is.
+ * Note the significant difference from \ref find_used_region which requires the
+ * address to exactly match the start of a region.
+ *
+ * @param r Memory region root.
+ * @param addr Address to look for.
+ * @return Pointer to owning memory region or \c NULL if no such exists.
+ */
 struct mem_region *find_addr_region(struct mem_region_root *r, vm_t addr);
 
 /**
diff --git a/src/elf.c b/src/elf.c
index 2cdcb8b..23f9b95 100644
--- a/src/elf.c
+++ b/src/elf.c
@@ -34,12 +34,13 @@ static uint8_t __elf_to_uvflags(uint8_t elf_flags)
 }
 
 static stat_t __elf_map_section(struct tcb *t,
-		vm_t va, size_t vaz,
-		vm_t vf, size_t vfz,
-		uint8_t flags)
+                                vm_t va, size_t vaz,
+                                vm_t vf, size_t vfz,
+                                uint8_t flags)
 {
 	size_t region_size;
-	vm_t v = alloc_fixed_region(&t->uvmem.region, va, vaz, &region_size, flags);
+	vm_t v = alloc_fixed_region(&t->uvmem.region, va, vaz, &region_size,
+	                            flags);
 	if (!v)
 		return ERR_INVAL;
 
@@ -59,7 +60,9 @@ static stat_t __elf_map_section(struct tcb *t,
 			memcpy((void *)page, (void *)(vf + runner), z);
 		}
 
-		if (map_vpage(t->proc.vmem, page, va + runner, flags, BASE_PAGE)) {
+		if (map_vpage(t->proc.vmem,
+		              page, va + runner,
+		              flags, BASE_PAGE)) {
 			free_page(BASE_PAGE, page);
 			return ERR_OOMEM;
 		}
@@ -77,17 +80,16 @@ static stat_t __elf_map_section(struct tcb *t,
  * @param phstart Program header start.
  * @param phnum Number of program header entries.
  * @param phsize Size of page header entry.
+ * @param OK on success, something else otherwise.
  */
 static stat_t __map_exec(struct tcb *t,
-		vm_t bin,
-		uint8_t ei_c,
-		vm_t phstart,
-                size_t phnum,
-		size_t phsize)
+                         vm_t bin,
+                         uint8_t ei_c,
+                         vm_t phstart,
+                         size_t phnum,
+                         size_t phsize)
 {
 	assert(t && is_proc(t));
-	/* temporarily visit process virtual memory */
-	use_vmem(t->proc.vmem);
 
 	/* create empty vmem so we don't have to worry about possible overlaps */
 	struct vmem *new_vmem = create_vmem();
@@ -106,7 +108,6 @@ static stat_t __map_exec(struct tcb *t,
 		destroy_vmem(new_vmem);
 		t->uvmem = old_uvmem;
 		t->proc.vmem = old_vmem;
-		use_vmem(t->rpc.vmem);
 		return ERR_OOMEM;
 	}
 
@@ -133,7 +134,6 @@ static stat_t __map_exec(struct tcb *t,
 
 			t->proc.vmem = old_vmem;
 			t->uvmem = old_uvmem;
-			use_vmem(t->rpc.vmem);
 			return ERR_OOMEM;
 		}
 	}
@@ -146,7 +146,6 @@ static stat_t __map_exec(struct tcb *t,
 
 	t->proc.vmem = new_vmem;
 	t->uvmem = new_uvmem;
-	use_vmem(t->rpc.vmem);
 	return OK;
 }
 
diff --git a/src/proc.c b/src/proc.c
index c1dfc64..090ae20 100644
--- a/src/proc.c
+++ b/src/proc.c
@@ -25,8 +25,6 @@ stat_t prepare_proc(struct tcb *t, vm_t bin, vm_t interp)
 		return ERR_INVAL;
 
 	t->callback = entry;
-	set_thread(t);
-	set_return(t, entry);
 	return OK;
 }
 
@@ -56,6 +54,8 @@ stat_t init_proc(void *fdt, vm_t *proc_fdt, vm_t *proc_initrd)
 	 * save them here before we switch */
 	use_tcb(t);
 
+	set_thread(t);
+	set_return(t, t->callback);
 	set_stack(t, t->rpc_stack - BASE_PAGE_SIZE);
 
 	stat_t ret = prepare_proc(t, get_init_base(fdt), 0);
diff --git a/src/uapi/proc.c b/src/uapi/proc.c
index 8d90687..51a1252 100644
--- a/src/uapi/proc.c
+++ b/src/uapi/proc.c
@@ -128,7 +128,11 @@ SYSCALL_DEFINE2(exec)(struct tcb *t, sys_arg_t bin, sys_arg_t interp)
 	if (prepare_proc(t, bin, interp))
 		return_args1(t, ERR_INVAL);
 
+	set_thread(t);
+	set_return(t, t->callback);
 	set_ret4(t, 0, t->tid, SYS_USER_SPAWNED, t->pid);
+
+	flush_tlb_full();
 }
 
 /**
@@ -150,16 +154,24 @@ SYSCALL_DEFINE2(spawn)(struct tcb *t, sys_arg_t bin, sys_arg_t interp)
 	if (!n)
 		return_args1(t, ERR_OOMEM);
 
-	/** @todo copy over bin and interp into new process, this is not enough */
 	n->notify_id = c->notify_id;
-	stat_t ret = OK;
-	if ((ret = prepare_proc(n, bin, interp))) {
+	if (prepare_proc(n, bin, interp)) {
 		/* this kills the thread */
 		orphanize(t);
 		unorphanize(t);
-		return_args1(t, ret);
+		return_args1(t, ERR_INVAL);
 	}
 
+	/** @todo should permissions be transferred? Probably, not but now there
+	 * is a slightly annoying asymmetry between fork+exec vs spawn... */
+
+	/* temporarily switch to new thread to manipulate stack */
+	use_tcb(n);
+	set_thread(n);
+	set_return(n, n->callback);
+	set_ret4(n, 0, n->tid, SYS_USER_SPAWNED, n->pid);
+	use_tcb(t);
+
 	return_args1(t, n->pid);
 }
 
diff --git a/src/vmem.c b/src/vmem.c
index 2752d23..76e0ece 100644
--- a/src/vmem.c
+++ b/src/vmem.c
@@ -330,7 +330,7 @@ vm_t map_shared_fixed_uvmem(struct tcb *t, pm_t start, size_t size,
 	assert(is_aligned(start, BASE_PAGE_SIZE));
 
 	const vm_t v = alloc_shared_region(&t->uvmem.region,
-			size, &size, flags, 0);
+	                                   size, &size, flags, 0);
 	if (!v)
 		return 0;
 
diff --git a/tests/common/sys.h b/tests/common/sys.h
index 3e98abf..0bee8bd 100644
--- a/tests/common/sys.h
+++ b/tests/common/sys.h
@@ -240,7 +240,7 @@ static inline enum sys_status sys_exec(uintptr_t bin, uintptr_t interp)
 /* negative IDs mean errors */
 static inline id_t sys_spawn(uintptr_t bin, uintptr_t interp)
 {
-	struct sys_ret r = syscall2(SYS_EXEC, bin, interp);
+	struct sys_ret r = syscall2(SYS_SPAWN, bin, interp);
 	return r.s;
 }
 
diff --git a/tests/spawn/init.c b/tests/spawn/init.c
new file mode 100644
index 0000000..8c25615
--- /dev/null
+++ b/tests/spawn/init.c
@@ -0,0 +1,34 @@
+#include <common/test.h>
+#include <common/cpio.h>
+
+START(pid, tid, d0, d1, d2, d3)
+{
+	UNUSED(pid);
+	UNUSED(tid);
+	UNUSED(d0);
+	UNUSED(d1);
+	UNUSED(d2);
+	UNUSED(d3);
+
+	check(pid == 0, "illegal pid for init\n");
+	printf("finding spawn in cpio archive %lx...\n", d2);
+	struct cpio_header *cp = cpio_find_file((const void *)d2,
+			"spawn", sizeof("spawn") - 1);
+
+	check(cp, "couldn't find spawn?\n");
+	long name_len = convnum(cp->c_namesize, 8, 16);
+	uintptr_t spawn = (uintptr_t)(cp) + align_up(sizeof(struct cpio_header) + name_len, 4);
+	printf("found spawn at %lx\n", spawn);
+
+	printf("doing spawn...\n");
+	id_t new = sys_spawn(spawn, 0);
+	check(new > 1, "spawn failed?\n");
+
+	printf("giving spawn CAP_POWER\n");
+	enum sys_status s = sys_set_cap(new, CAP_POWER);
+	check(s == OK, "CAP_POWER failed?\n");
+
+	printf("swapping to spawn\n");
+	s = sys_swap(new);
+	check(s == OK, "swap to spawn failed?\n");
+}
diff --git a/tests/spawn/source.mk b/tests/spawn/source.mk
new file mode 100644
index 0000000..9a1f676
--- /dev/null
+++ b/tests/spawn/source.mk
@@ -0,0 +1 @@
+DO	!= ./scripts/gen-simple -n spawn -p init -p spawn
diff --git a/tests/spawn/spawn.c b/tests/spawn/spawn.c
new file mode 100644
index 0000000..67d64f8
--- /dev/null
+++ b/tests/spawn/spawn.c
@@ -0,0 +1,18 @@
+#include <common/test.h>
+
+START(pid, tid, d0, d1, d2, d3)
+{
+	UNUSED(d2);
+	UNUSED(d3);
+
+	printf("pid = %ld, tid = %ld, d0 = %ld, d1 = %ld\n",
+			pid, tid, d0, d1);
+
+	check(pid == 0, "unexpected pid for spawn\n");
+	check(tid == 2, "unexpected tid for spawn\n");
+	check(d0 == SYS_USER_SPAWNED, "unexpected d0 for spawn\n");
+	check(d1 == 2, "unexpected d1 for spawn\n");
+
+	printf("causing shutdown, assuming init gave us CAP_POWER\n");
+	ok();
+}