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| author | Sergey Bugaev <bugaevc@gmail.com> | 2023-04-29 23:18:19 +0300 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-05-01 03:18:48 +0200 |
| commit | 4e506f67cbe6cd935377da65909f0606014459aa (patch) | |
| tree | aa701a83abdd2769c5ee3067cd048646af39ea22 /hurd | |
| parent | eb14819c14d190830df673c9a3089d82d6b7b8f7 (diff) | |
| download | glibc-4e506f67cbe6cd935377da65909f0606014459aa.zip glibc-4e506f67cbe6cd935377da65909f0606014459aa.tar.gz glibc-4e506f67cbe6cd935377da65909f0606014459aa.tar.bz2 | |
hurd: Replace reply port with a dead name on failed interruption
If we're trying to interrupt an interruptible RPC, but the server fails
to respond to our __interrupt_operation () call, we instead destroy the
reply port we were expecting the reply to the RPC on.
Instead of deallocating the name completely, replace it with a dead
name, so the name won't get reused for some other right, and deallocate
it in _hurd_intr_rpc_mach_msg once we return from the signal handler.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230429201822.2605207-4-bugaevc@gmail.com>
Diffstat (limited to 'hurd')
| -rw-r--r-- | hurd/hurdsig.c | 15 | ||||
| -rw-r--r-- | hurd/intr-msg.c | 1 |
2 files changed, 13 insertions, 3 deletions
diff --git a/hurd/hurdsig.c b/hurd/hurdsig.c index b3808f9..78ea59d 100644 --- a/hurd/hurdsig.c +++ b/hurd/hurdsig.c @@ -477,9 +477,18 @@ _hurdsig_abort_rpcs (struct hurd_sigstate *ss, int signo, int sigthread, if (reply) { /* The interrupt didn't work. - Destroy the receive right the thread is blocked on. */ - __mach_port_destroy (__mach_task_self (), *reply); - *reply = MACH_PORT_NULL; + Destroy the receive right the thread is blocked on, and + replace it with a dead name to keep the name from reuse until + the therad is done with it. To do this atomically, first + insert a send right, and then destroy the receive right, + turning the send right into a dead name. */ + err = __mach_port_insert_right (__mach_task_self (), + *reply, *reply, + MACH_MSG_TYPE_MAKE_SEND); + assert_perror (err); + err = __mach_port_mod_refs (__mach_task_self (), *reply, + MACH_PORT_RIGHT_RECEIVE, -1); + assert_perror (err); } /* The system call return value register now contains diff --git a/hurd/intr-msg.c b/hurd/intr-msg.c index 1a086b5..716d87a 100644 --- a/hurd/intr-msg.c +++ b/hurd/intr-msg.c @@ -305,6 +305,7 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, { /* Make sure we have a valid reply port. The one we were using may have been destroyed by interruption. */ + __mig_dealloc_reply_port (rcv_name); m->header.msgh_local_port = rcv_name = __mig_get_reply_port (); m->header.msgh_bits = msgh_bits; option = user_option; |