Module Name: src
Committed By: ryo
Date: Thu Nov 25 10:31:50 UTC 2021
Modified Files:
src/sys/kern: kern_exec.c
Log Message:
Reverte my previous changes kern_exec.c r1.512. It panics.
This changes was insufficient because es_emul is referenced by multiple execsw.
To generate a diff of this commit:
cvs rdiff -u -r1.512 -r1.513 src/sys/kern/kern_exec.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_exec.c
diff -u src/sys/kern/kern_exec.c:1.512 src/sys/kern/kern_exec.c:1.513
--- src/sys/kern/kern_exec.c:1.512 Thu Nov 25 02:37:38 2021
+++ src/sys/kern/kern_exec.c Thu Nov 25 10:31:50 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_exec.c,v 1.512 2021/11/25 02:37:38 ryo Exp $ */
+/* $NetBSD: kern_exec.c,v 1.513 2021/11/25 10:31:50 ryo Exp $ */
/*-
* Copyright (c) 2008, 2019, 2020 The NetBSD Foundation, Inc.
@@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.512 2021/11/25 02:37:38 ryo Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.513 2021/11/25 10:31:50 ryo Exp $");
#include "opt_exec.h"
#include "opt_execfmt.h"
@@ -139,8 +139,6 @@ static int copyinargs(struct execve_data
char * const *, execve_fetch_element_t, char **);
static int copyinargstrs(struct execve_data * restrict, char * const *,
execve_fetch_element_t, char **, size_t *, void (*)(const void *, size_t));
-static int exec_sigcode_alloc(const struct emul *);
-static void exec_sigcode_free(const struct emul *);
static int exec_sigcode_map(struct proc *, const struct emul *);
#if defined(DEBUG) && !defined(DEBUG_EXEC)
@@ -252,6 +250,8 @@ struct emul emul_netbsd = {
*/
krwlock_t exec_lock __cacheline_aligned;
+static kmutex_t sigobject_lock __cacheline_aligned;
+
/*
* Data used between a loadvm and execve part of an "exec" operation
*/
@@ -1815,7 +1815,7 @@ int
exec_add(struct execsw *esp, int count)
{
struct exec_entry *it;
- int i, error = 0;
+ int i;
if (count == 0) {
return 0;
@@ -1840,23 +1840,8 @@ exec_add(struct execsw *esp, int count)
for (i = 0; i < count; i++) {
it = kmem_alloc(sizeof(*it), KM_SLEEP);
it->ex_sw = &esp[i];
- error = exec_sigcode_alloc(it->ex_sw->es_emul);
- if (error != 0) {
- kmem_free(it, sizeof(*it));
- break;
- }
LIST_INSERT_HEAD(&ex_head, it, ex_list);
}
- /* If even one fails, remove them all back. */
- if (error != 0) {
- for (i--; i >= 0; i--) {
- it = LIST_FIRST(&ex_head);
- LIST_REMOVE(it, ex_list);
- exec_sigcode_free(it->ex_sw->es_emul);
- kmem_free(it, sizeof(*it));
- }
- return error;
- }
/* update execsw[] */
exec_init(0);
@@ -1901,7 +1886,6 @@ exec_remove(struct execsw *esp, int coun
next = LIST_NEXT(it, ex_list);
if (it->ex_sw == &esp[i]) {
LIST_REMOVE(it, ex_list);
- exec_sigcode_free(it->ex_sw->es_emul);
kmem_free(it, sizeof(*it));
break;
}
@@ -1935,6 +1919,7 @@ exec_init(int init_boot)
vaddr_t vmin = 0, vmax;
rw_init(&exec_lock);
+ mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE);
exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax,
maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL);
pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH,
@@ -2002,24 +1987,21 @@ exec_init(int init_boot)
}
static int
-exec_sigcode_alloc(const struct emul *e)
+exec_sigcode_map(struct proc *p, const struct emul *e)
{
vaddr_t va;
vsize_t sz;
int error;
struct uvm_object *uobj;
- KASSERT(rw_lock_held(&exec_lock));
-
- if (e == NULL || e->e_sigobject == NULL)
- return 0;
-
sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode;
- if (sz == 0)
+
+ if (e->e_sigobject == NULL || sz == 0) {
return 0;
+ }
/*
- * Create a sigobject for this emulation.
+ * If we don't have a sigobject for this emulation, create one.
*
* sigobject is an anonymous memory object (just like SYSV shared
* memory) that we keep a permanent reference to and that we map
@@ -2029,61 +2011,32 @@ exec_sigcode_alloc(const struct emul *e)
* We map it with PROT_READ|PROT_EXEC into the process just
* the way sys_mmap() would map it.
*/
- KASSERT(*e->e_sigobject == NULL);
- uobj = uao_create(sz, 0);
- (*uobj->pgops->pgo_reference)(uobj);
- va = vm_map_min(kernel_map);
- if ((error = uvm_map(kernel_map, &va, round_page(sz),
- uobj, 0, 0,
- UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW,
- UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) {
- printf("sigcode kernel mapping failed %d\n", error);
- (*uobj->pgops->pgo_detach)(uobj);
- return error;
- }
- memcpy((void *)va, e->e_sigcode, sz);
-#ifdef PMAP_NEED_PROCWR
- pmap_procwr(&proc0, va, sz);
-#endif
- uvm_unmap(kernel_map, va, va + round_page(sz));
- *e->e_sigobject = uobj;
-
- return 0;
-}
-
-static void
-exec_sigcode_free(const struct emul *e)
-{
- struct uvm_object *uobj;
-
- KASSERT(rw_lock_held(&exec_lock));
-
- if (e == NULL || e->e_sigobject == NULL)
- return;
-
- uobj = *e->e_sigobject;
- if (uobj == NULL)
- return;
-
- (*uobj->pgops->pgo_detach)(uobj);
- *e->e_sigobject = NULL;
-}
-
-static int
-exec_sigcode_map(struct proc *p, const struct emul *e)
-{
- vaddr_t va;
- vsize_t sz;
- int error;
- struct uvm_object *uobj;
-
- sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode;
- if (e->e_sigobject == NULL || sz == 0)
- return 0;
uobj = *e->e_sigobject;
- if (uobj == NULL)
- return 0;
+ if (uobj == NULL) {
+ mutex_enter(&sigobject_lock);
+ if ((uobj = *e->e_sigobject) == NULL) {
+ uobj = uao_create(sz, 0);
+ (*uobj->pgops->pgo_reference)(uobj);
+ va = vm_map_min(kernel_map);
+ if ((error = uvm_map(kernel_map, &va, round_page(sz),
+ uobj, 0, 0,
+ UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW,
+ UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) {
+ printf("kernel mapping failed %d\n", error);
+ (*uobj->pgops->pgo_detach)(uobj);
+ mutex_exit(&sigobject_lock);
+ return error;
+ }
+ memcpy((void *)va, e->e_sigcode, sz);
+#ifdef PMAP_NEED_PROCWR
+ pmap_procwr(&proc0, va, sz);
+#endif
+ uvm_unmap(kernel_map, va, va + round_page(sz));
+ *e->e_sigobject = uobj;
+ }
+ mutex_exit(&sigobject_lock);
+ }
/* Just a hint to uvm_map where to put it. */
va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr,
