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procfs_readdir: 

- fix a locking problem, using proclist_foreach_call.  PR/27098.
- correct snprintf size argument.
This commit is contained in:
yamt 2004-10-01 16:32:16 +00:00
parent 0994e6acb8
commit 269a1761b2
1 changed files with 83 additions and 52 deletions
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135
sys/miscfs/procfs/procfs_vnops.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: procfs_vnops.c,v 1.116 2004/10/01 14:09:55 yamt Exp $ */
/* $NetBSD: procfs_vnops.c,v 1.117 2004/10/01 16:32:16 yamt Exp $ */
/*
* Copyright (c) 1993, 1995
@ -76,7 +76,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: procfs_vnops.c,v 1.116 2004/10/01 14:09:55 yamt Exp $");
__KERNEL_RCSID(0, "$NetBSD: procfs_vnops.c,v 1.117 2004/10/01 16:32:16 yamt Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@ -107,6 +107,7 @@ __KERNEL_RCSID(0, "$NetBSD: procfs_vnops.c,v 1.116 2004/10/01 14:09:55 yamt Exp
*/
static int procfs_validfile_linux __P((struct proc *, struct mount *));
static int procfs_root_readdir_callback(struct proc *, void *);
/*
* This is a list of the valid names in the
@ -1000,6 +1001,55 @@ procfs_validfile_linux(p, mp)
(p == NULL || procfs_validfile(p, mp)));
}
struct procfs_root_readdir_ctx {
struct uio *uiop;
off_t *cookies;
int ncookies;
int skip;
int idx;
int error;
};
static int
procfs_root_readdir_callback(struct proc *p, void *arg)
{
struct procfs_root_readdir_ctx *ctxp = arg;
struct dirent d;
struct uio *uiop;
int error;
uiop = ctxp->uiop;
if (uiop->uio_resid < UIO_MX)
return -1; /* no space */
if (ctxp->skip) {
ctxp->skip--;
return 0;
}
memset(&d, 0, UIO_MX);
d.d_reclen = UIO_MX;
d.d_fileno = PROCFS_FILENO(p->p_pid, PFSproc, -1);
d.d_namlen = snprintf(d.d_name,
UIO_MX - offsetof(struct dirent, d_name), "%ld", (long)p->p_pid);
d.d_type = DT_DIR;
proclist_unlock_read();
error = uiomove(&d, UIO_MX, uiop);
proclist_lock_read();
if (error) {
ctxp->error = error;
return -1;
}
ctxp->ncookies++;
if (ctxp->cookies)
*(ctxp->cookies)++ = ctxp->idx + 1;
ctxp->idx++;
return 0;
}
/*
* readdir returns directory entries from pfsnode (vp).
*
@ -1030,9 +1080,10 @@ procfs_readdir(v)
off_t i;
int error;
off_t *cookies = NULL;
int ncookies, left, skip, j;
int ncookies;
struct vnode *vp;
const struct proc_target *pt;
struct procfs_root_readdir_ctx ctx;
vp = ap->a_vp;
pfs = VTOPFS(vp);
@ -1155,19 +1206,12 @@ procfs_readdir(v)
* this is for the root of the procfs filesystem
* what is needed are special entries for "curproc"
* and "self" followed by an entry for each process
* on allproc
#ifdef PROCFS_ZOMBIE
* and deadproc and zombproc.
#endif
* on allproc.
*/
case PFSroot: {
int pcnt = i, nc = 0;
const struct proclist_desc *pd;
volatile struct proc *p;
int nc = 0;
if (pcnt > 4)
pcnt = 4;
if (ap->a_ncookies) {
/*
* XXX Potentially allocating too much space here,
@ -1177,17 +1221,9 @@ procfs_readdir(v)
M_TEMP, M_WAITOK);
*ap->a_cookies = cookies;
}
/*
* XXX: THIS LOOP ASSUMES THAT allproc IS THE FIRST
* PROCLIST IN THE proclists!
*/
proclist_lock_read();
pd = proclists;
#ifdef PROCFS_ZOMBIE
again:
#endif
for (p = LIST_FIRST(pd->pd_list);
p != NULL && uio->uio_resid >= UIO_MX; i++, pcnt++) {
error = 0;
/* 0 ... 3 are static entries. */
for (; i <= 3 && uio->uio_resid >= UIO_MX; i++) {
switch (i) {
case 0: /* `.' */
case 1: /* `..' */
@ -1211,20 +1247,6 @@ procfs_readdir(v)
memcpy(d.d_name, "self", sizeof("self"));
d.d_type = DT_LNK;
break;
default:
while (pcnt < i) {
pcnt++;
p = LIST_NEXT(p, p_list);
if (!p)
goto done;
}
d.d_fileno = PROCFS_FILENO(p->p_pid, PFSproc, -1);
d.d_namlen = snprintf(d.d_name,
sizeof(d.d_name), "%ld", (long)p->p_pid);
d.d_type = DT_DIR;
p = LIST_NEXT(p, p_list);
break;
}
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
@ -1233,22 +1255,31 @@ procfs_readdir(v)
if (cookies)
*cookies++ = i + 1;
}
done:
#ifdef PROCFS_ZOMBIE
pd++;
if (p == NULL && pd->pd_list != NULL)
goto again;
#endif
proclist_unlock_read();
skip = i - pcnt;
if (skip >= nproc_root_targets)
/* 4 ... are process entries. */
ctx.uiop = uio;
ctx.error = 0;
ctx.idx = 4;
ctx.skip = i - ctx.idx;
ctx.cookies = cookies;
ctx.ncookies = nc;
proclist_foreach_call(&allproc,
procfs_root_readdir_callback, &ctx);
cookies = ctx.cookies;
nc = ctx.ncookies;
error = ctx.error;
if (error)
break;
left = nproc_root_targets - skip;
for (j = 0, pt = &proc_root_targets[0];
uio->uio_resid >= UIO_MX && j < left;
pt++, j++, i++) {
/* misc entries. */
if (i >= ctx.idx + nproc_root_targets)
break;
pt = &proc_root_targets[0];
if (i < ctx.idx)
i = ctx.idx;
for (pt = &proc_root_targets[i - ctx.idx];
uio->uio_resid >= UIO_MX &&
pt < &proc_root_targets[nproc_root_targets];
pt++, i++) {
if (pt->pt_valid &&
(*pt->pt_valid)(NULL, vp->v_mount) == 0)
continue;