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Reverte my previous changes kern_exec.c r1.512. It panics. 

This changes was insufficient because es_emul is referenced by multiple execsw.
This commit is contained in:
ryo 2021-11-25 10:31:50 +00:00
parent 4b93d1ada6
commit 4754a9ec3b
1 changed files with 35 additions and 82 deletions
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117
sys/kern/kern_exec.c
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@ -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 * restrict, char * const *,
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 count)
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);
uobj = *e->e_sigobject;
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);
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;
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,