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Add a global sx sigio_lock to protect the pointer to the sigio object

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of a socket.  This avoids lock order reversal caused by locking a
process in pgsigio().

sowakeup() and the callers of it (sowwakeup, soisconnected, etc.) now
require sigio_lock to be locked.  Provide sowwakeup_locked(),
soisconnected_locked(), and so on in case where we have to modify a
socket and wake up a process atomically.
This commit is contained in:
Seigo Tanimura 2002-04-27 08:24:29 +00:00
parent f5d157fb51
commit d48d4b2501
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=95552
11 changed files with 232 additions and 51 deletions
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2
sys/kern/kern_descrip.c
View File

@ -113,6 +113,7 @@ struct filelist filehead; /* head of list of open files */
int nfiles; /* actual number of open files */
extern int cmask;
struct sx filelist_lock; /* sx to protect filelist */
struct sx sigio_lock; /* sx to protect pointers to sigio */
/*
* System calls on descriptors.
@ -2186,4 +2187,5 @@ filelistinit(dummy)
NULL, NULL, UMA_ALIGN_PTR, 0);
sx_init(&filelist_lock, "filelist lock");
sx_init(&sigio_lock, "sigio lock");
}

88
sys/kern/uipc_sockbuf.c
View File

@ -107,11 +107,12 @@ soisconnecting(so)
}
void
soisconnected(so)
soisconnected_locked(so)
struct socket *so;
{
struct socket *head = so->so_head;
SIGIO_ASSERT(SX_SLOCKED); /* XXX */
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
so->so_state |= SS_ISCONNECTED;
if (head && (so->so_state & SS_INCOMP)) {
@ -120,6 +121,41 @@ soisconnected(so)
so->so_upcallarg = head->so_accf->so_accept_filter_arg;
so->so_rcv.sb_flags |= SB_UPCALL;
so->so_options &= ~SO_ACCEPTFILTER;
SIGIO_SUNLOCK(); /* XXX */
so->so_upcall(so, so->so_upcallarg, 0);
SIGIO_SLOCK();
return;
}
TAILQ_REMOVE(&head->so_incomp, so, so_list);
head->so_incqlen--;
so->so_state &= ~SS_INCOMP;
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
so->so_state |= SS_COMP;
sorwakeup_locked(head);
wakeup_one(&head->so_timeo);
} else {
wakeup(&so->so_timeo);
sorwakeup_locked(so);
sowwakeup_locked(so);
}
}
void
soisconnected(so)
struct socket *so;
{
struct socket *head = so->so_head;
SIGIO_SLOCK();
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
so->so_state |= SS_ISCONNECTED;
if (head && (so->so_state & SS_INCOMP)) {
if ((so->so_options & SO_ACCEPTFILTER) != 0) {
so->so_upcall = head->so_accf->so_accept_filter->accf_callback;
so->so_upcallarg = head->so_accf->so_accept_filter_arg;
so->so_rcv.sb_flags |= SB_UPCALL;
so->so_options &= ~SO_ACCEPTFILTER;
SIGIO_SUNLOCK();
so->so_upcall(so, so->so_upcallarg, 0);
return;
}
@ -129,13 +165,14 @@ soisconnected(so)
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
head->so_qlen++;
so->so_state |= SS_COMP;
sorwakeup(head);
sorwakeup_locked(head);
wakeup_one(&head->so_timeo);
} else {
wakeup(&so->so_timeo);
sorwakeup(so);
sowwakeup(so);
sorwakeup_locked(so);
sowwakeup_locked(so);
}
SIGIO_SUNLOCK();
}
void
@ -143,11 +180,26 @@ soisdisconnecting(so)
register struct socket *so;
{
SIGIO_SLOCK();
so->so_state &= ~SS_ISCONNECTING;
so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
wakeup((caddr_t)&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
sowwakeup_locked(so);
sorwakeup_locked(so);
SIGIO_SUNLOCK();
}
void
soisdisconnected_locked(so)
register struct socket *so;
{
SIGIO_ASSERT(SX_LOCKED);
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
wakeup((caddr_t)&so->so_timeo);
sowwakeup_locked(so);
sorwakeup_locked(so);
}
void
@ -155,11 +207,9 @@ soisdisconnected(so)
register struct socket *so;
{
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
wakeup((caddr_t)&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
SIGIO_SLOCK();
soisdisconnected_locked(so);
SIGIO_SUNLOCK();
}
/*
@ -215,9 +265,9 @@ sonewconn(head, connstatus)
head->so_incqlen++;
}
if (connstatus) {
sorwakeup(head);
wakeup((caddr_t)&head->so_timeo);
so->so_state |= connstatus;
SIGIO_SLOCK();
sorwakeup_locked(head);
SIGIO_SUNLOCK();
}
return (so);
}
@ -237,8 +287,10 @@ socantsendmore(so)
struct socket *so;
{
SIGIO_SLOCK();
so->so_state |= SS_CANTSENDMORE;
sowwakeup(so);
sowwakeup_locked(so);
SIGIO_SUNLOCK();
}
void
@ -246,8 +298,10 @@ socantrcvmore(so)
struct socket *so;
{
SIGIO_SLOCK();
so->so_state |= SS_CANTRCVMORE;
sorwakeup(so);
sorwakeup_locked(so);
SIGIO_SUNLOCK();
}
/*
@ -296,6 +350,8 @@ sowakeup(so, sb)
register struct socket *so;
register struct sockbuf *sb;
{
SIGIO_ASSERT(SX_LOCKED);
selwakeup(&sb->sb_sel);
sb->sb_flags &= ~SB_SEL;
if (sb->sb_flags & SB_WAIT) {

88
sys/kern/uipc_socket2.c
View File

@ -107,11 +107,12 @@ soisconnecting(so)
}
void
soisconnected(so)
soisconnected_locked(so)
struct socket *so;
{
struct socket *head = so->so_head;
SIGIO_ASSERT(SX_SLOCKED); /* XXX */
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
so->so_state |= SS_ISCONNECTED;
if (head && (so->so_state & SS_INCOMP)) {
@ -120,6 +121,41 @@ soisconnected(so)
so->so_upcallarg = head->so_accf->so_accept_filter_arg;
so->so_rcv.sb_flags |= SB_UPCALL;
so->so_options &= ~SO_ACCEPTFILTER;
SIGIO_SUNLOCK(); /* XXX */
so->so_upcall(so, so->so_upcallarg, 0);
SIGIO_SLOCK();
return;
}
TAILQ_REMOVE(&head->so_incomp, so, so_list);
head->so_incqlen--;
so->so_state &= ~SS_INCOMP;
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
so->so_state |= SS_COMP;
sorwakeup_locked(head);
wakeup_one(&head->so_timeo);
} else {
wakeup(&so->so_timeo);
sorwakeup_locked(so);
sowwakeup_locked(so);
}
}
void
soisconnected(so)
struct socket *so;
{
struct socket *head = so->so_head;
SIGIO_SLOCK();
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
so->so_state |= SS_ISCONNECTED;
if (head && (so->so_state & SS_INCOMP)) {
if ((so->so_options & SO_ACCEPTFILTER) != 0) {
so->so_upcall = head->so_accf->so_accept_filter->accf_callback;
so->so_upcallarg = head->so_accf->so_accept_filter_arg;
so->so_rcv.sb_flags |= SB_UPCALL;
so->so_options &= ~SO_ACCEPTFILTER;
SIGIO_SUNLOCK();
so->so_upcall(so, so->so_upcallarg, 0);
return;
}
@ -129,13 +165,14 @@ soisconnected(so)
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
head->so_qlen++;
so->so_state |= SS_COMP;
sorwakeup(head);
sorwakeup_locked(head);
wakeup_one(&head->so_timeo);
} else {
wakeup(&so->so_timeo);
sorwakeup(so);
sowwakeup(so);
sorwakeup_locked(so);
sowwakeup_locked(so);
}
SIGIO_SUNLOCK();
}
void
@ -143,11 +180,26 @@ soisdisconnecting(so)
register struct socket *so;
{
SIGIO_SLOCK();
so->so_state &= ~SS_ISCONNECTING;
so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
wakeup((caddr_t)&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
sowwakeup_locked(so);
sorwakeup_locked(so);
SIGIO_SUNLOCK();
}
void
soisdisconnected_locked(so)
register struct socket *so;
{
SIGIO_ASSERT(SX_LOCKED);
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
wakeup((caddr_t)&so->so_timeo);
sowwakeup_locked(so);
sorwakeup_locked(so);
}
void
@ -155,11 +207,9 @@ soisdisconnected(so)
register struct socket *so;
{
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
wakeup((caddr_t)&so->so_timeo);
sowwakeup(so);
sorwakeup(so);
SIGIO_SLOCK();
soisdisconnected_locked(so);
SIGIO_SUNLOCK();
}
/*
@ -215,9 +265,9 @@ sonewconn(head, connstatus)
head->so_incqlen++;
}
if (connstatus) {
sorwakeup(head);
wakeup((caddr_t)&head->so_timeo);
so->so_state |= connstatus;
SIGIO_SLOCK();
sorwakeup_locked(head);
SIGIO_SUNLOCK();
}
return (so);
}
@ -237,8 +287,10 @@ socantsendmore(so)
struct socket *so;
{
SIGIO_SLOCK();
so->so_state |= SS_CANTSENDMORE;
sowwakeup(so);
sowwakeup_locked(so);
SIGIO_SUNLOCK();
}
void
@ -246,8 +298,10 @@ socantrcvmore(so)
struct socket *so;
{
SIGIO_SLOCK();
so->so_state |= SS_CANTRCVMORE;
sorwakeup(so);
sorwakeup_locked(so);
SIGIO_SUNLOCK();
}
/*
@ -296,6 +350,8 @@ sowakeup(so, sb)
register struct socket *so;
register struct sockbuf *sb;
{
SIGIO_ASSERT(SX_LOCKED);
selwakeup(&sb->sb_sel);
sb->sb_flags &= ~SB_SEL;
if (sb->sb_flags & SB_WAIT) {

4
sys/net/rtsock.c
View File

@ -146,8 +146,10 @@ rts_attach(struct socket *so, int proto, struct thread *td)
}
rp->rcb_faddr = &route_src;
route_cb.any_count++;
soisconnected(so);
SIGIO_SLOCK();
soisconnected_locked(so);
so->so_options |= SO_USELOOPBACK;
SIGIO_SUNLOCK();
splx(s);
return 0;
}

5
sys/netinet/accf_data.c
View File

@ -56,12 +56,15 @@ static void
sohasdata(struct socket *so, void *arg, int waitflag)
{
SIGIO_SLOCK();
if (!soreadable(so)) {
SIGIO_SUNLOCK();
return;
}
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
soisconnected_locked(so);
SIGIO_SUNLOCK();
return;
}

12
sys/netinet/accf_http.c
View File

@ -197,9 +197,11 @@ sohashttpget(struct socket *so, void *arg, int waitflag)
fallout:
DPRINT("fallout");
SIGIO_SLOCK();
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
soisconnected_locked(so);
SIGIO_SUNLOCK();
return;
}
@ -269,9 +271,11 @@ soparsehttpvers(struct socket *so, void *arg, int waitflag)
fallout:
DPRINT("fallout");
SIGIO_SLOCK();
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
soisconnected_locked(so);
SIGIO_SUNLOCK();
return;
}
@ -339,8 +343,10 @@ soishttpconnected(struct socket *so, void *arg, int waitflag)
return;
gotit:
SIGIO_SLOCK();
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
soisconnected_locked(so);
SIGIO_SUNLOCK();
return;
}

6
sys/netinet/tcp_input.c
View File

@ -1842,10 +1842,14 @@ tcp_input(m, off0)
* specification, but if we don't get a FIN
* we'll hang forever.
*/
SIGIO_SLOCK();
if (so->so_state & SS_CANTRCVMORE) {
soisdisconnected(so);
soisdisconnected_locked(so);
SIGIO_SUNLOCK();
callout_reset(tp->tt_2msl, tcp_maxidle,
tcp_timer_2msl, tp);
} else {
SIGIO_SUNLOCK();
}
tp->t_state = TCPS_FIN_WAIT_2;
}

6
sys/netinet/tcp_reass.c
View File

@ -1842,10 +1842,14 @@ tcp_input(m, off0)
* specification, but if we don't get a FIN
* we'll hang forever.
*/
SIGIO_SLOCK();
if (so->so_state & SS_CANTRCVMORE) {
soisdisconnected(so);
soisdisconnected_locked(so);
SIGIO_SUNLOCK();
callout_reset(tp->tt_2msl, tcp_maxidle,
tcp_timer_2msl, tp);
} else {
SIGIO_SUNLOCK();
}
tp->t_state = TCPS_FIN_WAIT_2;
}

4
sys/netkey/keysock.c
View File

@ -428,8 +428,10 @@ key_attach(struct socket *so, int proto, struct thread *td)
key_cb.any_count++;
kp->kp_raw.rcb_laddr = &key_src;
kp->kp_raw.rcb_faddr = &key_dst;
soisconnected(so);
SIGIO_SLOCK();
soisconnected_locked(so);
so->so_options |= SO_USELOOPBACK;
SIGIO_SUNLOCK();
splx(s);
return 0;

17
sys/sys/filedesc.h
View File

@ -37,8 +37,9 @@
#ifndef _SYS_FILEDESC_H_
#define _SYS_FILEDESC_H_
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/queue.h>
/*
@ -134,12 +135,24 @@ SLIST_HEAD(sigiolst, sigio);
#define FILEDESC_LOCK_DESC "filedesc structure"
extern struct sx sigio_lock;
/* Lock a file descriptor table. */
#define FILEDESC_LOCK(fd) mtx_lock(&(fd)->fd_mtx)
#define FILEDESC_UNLOCK(fd) mtx_unlock(&(fd)->fd_mtx)
#define FILEDESC_LOCKED(fd) mtx_owned(&(fd)->fd_mtx)
#define FILEDESC_LOCK_ASSERT(fd, type) mtx_assert(&(fd)->fd_mtx, (type))
/*
* Lock the pointers for a sigio object in the underlying objects of
* a file descriptor.
*/
#define SIGIO_SLOCK() sx_slock(&sigio_lock)
#define SIGIO_XLOCK() sx_xlock(&sigio_lock)
#define SIGIO_SUNLOCK() sx_sunlock(&sigio_lock)
#define SIGIO_XUNLOCK() sx_xunlock(&sigio_lock)
#define SIGIO_ASSERT(what) sx_assert(&sigio_lock, what)
int closef(struct file *fp, struct thread *p);
int dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd,
int mode, int error);

51
sys/sys/socketvar.h
View File

@ -38,6 +38,10 @@
#define _SYS_SOCKETVAR_H_
#include <sys/queue.h> /* for TAILQ macros */
#include <sys/filedesc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/selinfo.h> /* for struct selinfo */
#include <vm/uma.h>
@ -51,6 +55,19 @@ typedef u_quad_t so_gen_t;
struct accept_filter;
/*
* List of locks:
* (c) const, inited in either socreate() or sonewconn()
* (m) sb_mtx mutex
* (mr) so_rcv.sb_mtx mutex
* (sg) sigio_lock sx
* (sh) sohead_lock sx
*
* Lock of so_rcv.sb_mtx can duplicate, provided that sohead_lock
* is exclusively locked.
*
* Brackets mean that this data is not protected yet.
*/
struct socket {
int so_count; /* reference count */
short so_type; /* generic type, see socket.h */
@ -80,7 +97,7 @@ struct socket {
short so_qlimit; /* max number queued connections */
short so_timeo; /* connection timeout */
u_short so_error; /* error affecting connection */
struct sigio *so_sigio; /* information for async I/O or
struct sigio *so_sigio; /* [sg] information for async I/O or
out of band data (SIGURG) */
u_long so_oobmark; /* chars to oob mark */
TAILQ_HEAD(, aiocblist) so_aiojobq; /* AIO ops waiting on socket */
@ -267,15 +284,29 @@ struct xsocket {
sofree(so); \
} while(0)
#define sorwakeup(so) do { \
if (sb_notify(&(so)->so_rcv)) \
sowakeup((so), &(so)->so_rcv); \
} while (0)
#define sorwakeup_locked(so) do { \
SIGIO_ASSERT(SX_SLOCKED); /* XXX */ \
if (sb_notify(&(so)->so_rcv)) \
sowakeup((so), &(so)->so_rcv); \
} while (0)
#define sowwakeup(so) do { \
if (sb_notify(&(so)->so_snd)) \
sowakeup((so), &(so)->so_snd); \
} while (0)
#define sorwakeup(so) do { \
SIGIO_SLOCK(); \
sorwakeup_locked(so); \
SIGIO_SUNLOCK(); \
} while (0)
#define sowwakeup_locked(so) do { \
SIGIO_ASSERT(SX_SLOCKED); /* XXX */ \
if (sb_notify(&(so)->so_snd)) \
sowakeup((so), &(so)->so_snd); \
} while (0)
#define sowwakeup(so) do { \
SIGIO_SLOCK(); \
sowwakeup_locked(so); \
SIGIO_SUNLOCK(); \
} while (0)
#ifdef _KERNEL
@ -387,8 +418,10 @@ void sofree(struct socket *so);
int sogetopt(struct socket *so, struct sockopt *sopt);
void sohasoutofband(struct socket *so);
void soisconnected(struct socket *so);
void soisconnected_locked(struct socket *so);
void soisconnecting(struct socket *so);
void soisdisconnected(struct socket *so);
void soisdisconnected_locked(struct socket *so);
void soisdisconnecting(struct socket *so);
int solisten(struct socket *so, int backlog, struct thread *td);
struct socket *