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author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2021-03-23 22:38:54 +0000 |
---|---|---|
committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2021-03-23 22:40:10 +0000 |
commit | c3b287be74e12bdb15ed36e98d24fd42f8ee9122 (patch) | |
tree | 82a9f85685a35bf5b12e480ee6ed1abc24103dc8 | |
parent | a4ea18ec6cc3f1370efab09bc18c1badbf74aa13 (diff) | |
download | glibc-c3b287be74e12bdb15ed36e98d24fd42f8ee9122.zip glibc-c3b287be74e12bdb15ed36e98d24fd42f8ee9122.tar.gz glibc-c3b287be74e12bdb15ed36e98d24fd42f8ee9122.tar.bz2 |
hurd: handle EINTR during critical sections
During critical sections, signal handling is deferred and thus RPCs return
EINTR, even if SA_RESTART is set. We thus have to restart the whole critical
section in that case.
This also adds HURD_CRITICAL_UNLOCK in the cases where one wants to
break the section in the middle.
29 files changed, 139 insertions, 4 deletions
diff --git a/hurd/dtable.c b/hurd/dtable.c index 9437f8c..bbd3bfc 100644 --- a/hurd/dtable.c +++ b/hurd/dtable.c @@ -189,6 +189,7 @@ ctty_new_pgrp (void) { int i; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_dtable_lock); @@ -224,8 +225,18 @@ ctty_new_pgrp (void) /* This fd has a ctty-special port. We need a new one, to tell the io server of our different process group. */ io_t new; - if (__term_open_ctty (port, _hurd_pid, _hurd_pgrp, &new)) - new = MACH_PORT_NULL; + error_t err; + if ((err = __term_open_ctty (port, _hurd_pid, _hurd_pgrp, &new))) + { + if (err == EINTR) + { + /* Got a signal while inside an RPC of the critical section, retry again */ + __mutex_unlock (&_hurd_dtable_lock); + HURD_CRITICAL_UNLOCK; + goto retry; + } + new = MACH_PORT_NULL; + } _hurd_port_set (&d->ctty, new); } diff --git a/hurd/geteuids.c b/hurd/geteuids.c index 840d80a..7fb8b0e 100644 --- a/hurd/geteuids.c +++ b/hurd/geteuids.c @@ -26,6 +26,7 @@ geteuids (int n, uid_t *uidset) int nuids; void *crit; +retry: crit = _hurd_critical_section_lock (); __mutex_lock (&_hurd_id.lock); @@ -33,6 +34,9 @@ geteuids (int n, uid_t *uidset) { __mutex_unlock (&_hurd_id.lock); _hurd_critical_section_unlock (crit); + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return __hurd_fail (err); } diff --git a/hurd/hurd/signal.h b/hurd/hurd/signal.h index 37b7dec..db9a02f 100644 --- a/hurd/hurd/signal.h +++ b/hurd/hurd/signal.h @@ -277,6 +277,10 @@ _hurd_critical_section_unlock (void *our_lock) { void *__hurd_critical__ = _hurd_critical_section_lock () #define HURD_CRITICAL_END \ _hurd_critical_section_unlock (__hurd_critical__); } while (0) + +/* This one can be used inside the C scoping level, for early exits. */ +#define HURD_CRITICAL_UNLOCK \ + _hurd_critical_section_unlock (__hurd_critical__); /* Initialize the signal code, and start the signal thread. Arguments give the "init ints" from exec_startup. */ diff --git a/hurd/hurdexec.c b/hurd/hurdexec.c index db8989e..7dca090 100644 --- a/hurd/hurdexec.c +++ b/hurd/hurdexec.c @@ -123,6 +123,7 @@ _hurd_exec_paths (task_t task, file_t file, ss = _hurd_self_sigstate (); +retry: assert (! __spin_lock_locked (&ss->critical_section_lock)); __spin_lock (&ss->critical_section_lock); @@ -429,6 +430,9 @@ _hurd_exec_paths (task_t task, file_t file, /* Safe to let signals happen now. */ _hurd_critical_section_unlock (ss); + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; outargs: free (args); diff --git a/hurd/hurdfchdir.c b/hurd/hurdfchdir.c index 62a6ed1..84dc292 100644 --- a/hurd/hurdfchdir.c +++ b/hurd/hurdfchdir.c @@ -32,6 +32,7 @@ _hurd_change_directory_port_from_fd (struct hurd_port *portcell, int fd) if (!d) return __hurd_fail (EBADF); +retry: HURD_CRITICAL_BEGIN; ret = HURD_PORT_USE (&d->port, @@ -53,6 +54,9 @@ _hurd_change_directory_port_from_fd (struct hurd_port *portcell, int fd) })); HURD_CRITICAL_END; + if (ret == -1 && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return ret; } diff --git a/hurd/hurdsock.c b/hurd/hurdsock.c index 79395d9..04e86b4 100644 --- a/hurd/hurdsock.c +++ b/hurd/hurdsock.c @@ -52,6 +52,7 @@ _hurd_socket_server (int domain, int dead) return MACH_PORT_NULL; } +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&lock); @@ -101,6 +102,9 @@ _hurd_socket_server (int domain, int dead) __mutex_unlock (&lock); HURD_CRITICAL_END; + if (server == MACH_PORT_NULL && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return server; } diff --git a/hurd/seteuids.c b/hurd/seteuids.c index 19db47f..df0922f 100644 --- a/hurd/seteuids.c +++ b/hurd/seteuids.c @@ -31,6 +31,7 @@ seteuids (int n, const uid_t *uids) for (i = 0; i < n; ++i) new[i] = uids[i]; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -47,6 +48,9 @@ seteuids (int n, const uid_t *uids) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/faccessat.c b/sysdeps/mach/hurd/faccessat.c index f421a53..0770271 100644 --- a/sysdeps/mach/hurd/faccessat.c +++ b/sysdeps/mach/hurd/faccessat.c @@ -127,6 +127,7 @@ __faccessat_common (int fd, const char *file, int type, int at_flags, rcrdir = rcwdir = MACH_PORT_NULL; + retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -172,6 +173,9 @@ __faccessat_common (int fd, const char *file, int type, int at_flags, __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (rcrdir != MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), rcrdir); diff --git a/sysdeps/mach/hurd/fork.c b/sysdeps/mach/hurd/fork.c index 1c5299e..92a5169 100644 --- a/sysdeps/mach/hurd/fork.c +++ b/sysdeps/mach/hurd/fork.c @@ -70,6 +70,7 @@ __fork (void) __run_fork_handlers (atfork_run_prepare, true); ss = _hurd_self_sigstate (); +retry: __spin_lock (&ss->critical_section_lock); #undef LOSE @@ -718,6 +719,9 @@ __fork (void) } _hurd_critical_section_unlock (ss); + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (!err) { diff --git a/sysdeps/mach/hurd/getegid.c b/sysdeps/mach/hurd/getegid.c index 5a3db22..1929d74 100644 --- a/sysdeps/mach/hurd/getegid.c +++ b/sysdeps/mach/hurd/getegid.c @@ -27,6 +27,7 @@ __getegid (void) error_t err; gid_t egid; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -49,6 +50,9 @@ __getegid (void) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (egid == -1 && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return egid; } diff --git a/sysdeps/mach/hurd/geteuid.c b/sysdeps/mach/hurd/geteuid.c index a7af5a9..5312d6b 100644 --- a/sysdeps/mach/hurd/geteuid.c +++ b/sysdeps/mach/hurd/geteuid.c @@ -27,6 +27,7 @@ __geteuid (void) error_t err; uid_t euid; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -49,6 +50,9 @@ __geteuid (void) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (euid == -1 && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return euid; } diff --git a/sysdeps/mach/hurd/getgid.c b/sysdeps/mach/hurd/getgid.c index aa13884..c89e742 100644 --- a/sysdeps/mach/hurd/getgid.c +++ b/sysdeps/mach/hurd/getgid.c @@ -27,6 +27,7 @@ __getgid (void) error_t err; gid_t gid; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -46,6 +47,9 @@ __getgid (void) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (gid == -1 && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return gid; } diff --git a/sysdeps/mach/hurd/getgroups.c b/sysdeps/mach/hurd/getgroups.c index 5f036f8..6b59d4a 100644 --- a/sysdeps/mach/hurd/getgroups.c +++ b/sysdeps/mach/hurd/getgroups.c @@ -31,6 +31,7 @@ __getgroups (int n, gid_t *gidset) if (n < 0) return __hurd_fail (EINVAL); +retry: crit = _hurd_critical_section_lock (); __mutex_lock (&_hurd_id.lock); @@ -38,6 +39,9 @@ __getgroups (int n, gid_t *gidset) { __mutex_unlock (&_hurd_id.lock); _hurd_critical_section_unlock (crit); + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return __hurd_fail (err); } diff --git a/sysdeps/mach/hurd/getresgid.c b/sysdeps/mach/hurd/getresgid.c index 9cae591..52838b8 100644 --- a/sysdeps/mach/hurd/getresgid.c +++ b/sysdeps/mach/hurd/getresgid.c @@ -28,6 +28,7 @@ __getresgid (gid_t *rgid, gid_t *egid, gid_t *sgid) { error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -49,6 +50,9 @@ __getresgid (gid_t *rgid, gid_t *egid, gid_t *sgid) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return __hurd_fail (err); } diff --git a/sysdeps/mach/hurd/getresuid.c b/sysdeps/mach/hurd/getresuid.c index 02995db..732e416 100644 --- a/sysdeps/mach/hurd/getresuid.c +++ b/sysdeps/mach/hurd/getresuid.c @@ -28,6 +28,7 @@ __getresuid (uid_t *ruid, uid_t *euid, uid_t *suid) { error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -49,6 +50,9 @@ __getresuid (uid_t *ruid, uid_t *euid, uid_t *suid) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return __hurd_fail (err); } diff --git a/sysdeps/mach/hurd/getuid.c b/sysdeps/mach/hurd/getuid.c index fc4a441..1aadb74 100644 --- a/sysdeps/mach/hurd/getuid.c +++ b/sysdeps/mach/hurd/getuid.c @@ -27,6 +27,7 @@ __getuid (void) error_t err; uid_t uid; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); @@ -46,6 +47,9 @@ __getuid (void) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (uid == -1 && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return uid; } diff --git a/sysdeps/mach/hurd/group_member.c b/sysdeps/mach/hurd/group_member.c index c5256f1..72681a8 100644 --- a/sysdeps/mach/hurd/group_member.c +++ b/sysdeps/mach/hurd/group_member.c @@ -28,6 +28,7 @@ __group_member (gid_t gid) error_t err; void *crit; +retry: crit = _hurd_critical_section_lock (); __mutex_lock (&_hurd_id.lock); @@ -45,6 +46,9 @@ __group_member (gid_t gid) __mutex_unlock (&_hurd_id.lock); _hurd_critical_section_unlock (crit); + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setegid.c b/sysdeps/mach/hurd/setegid.c index f0258d3..1396e19 100644 --- a/sysdeps/mach/hurd/setegid.c +++ b/sysdeps/mach/hurd/setegid.c @@ -29,6 +29,7 @@ setegid (gid_t gid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -55,6 +56,9 @@ setegid (gid_t gid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/seteuid.c b/sysdeps/mach/hurd/seteuid.c index 637015c..97eb22c 100644 --- a/sysdeps/mach/hurd/seteuid.c +++ b/sysdeps/mach/hurd/seteuid.c @@ -29,6 +29,7 @@ seteuid (uid_t uid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -55,6 +56,9 @@ seteuid (uid_t uid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setgid.c b/sysdeps/mach/hurd/setgid.c index 6e0672d..c6a64c9 100644 --- a/sysdeps/mach/hurd/setgid.c +++ b/sysdeps/mach/hurd/setgid.c @@ -32,6 +32,7 @@ __setgid (gid_t gid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -81,6 +82,9 @@ __setgid (gid_t gid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setgroups.c b/sysdeps/mach/hurd/setgroups.c index fc78de3..cb6b899 100644 --- a/sysdeps/mach/hurd/setgroups.c +++ b/sysdeps/mach/hurd/setgroups.c @@ -34,6 +34,7 @@ setgroups (size_t n, const gid_t *groups) for (i = 0; i < n; ++i) new[i] = groups[i]; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -50,6 +51,9 @@ setgroups (size_t n, const gid_t *groups) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setitimer.c b/sysdeps/mach/hurd/setitimer.c index e23e79a..4931644 100644 --- a/sysdeps/mach/hurd/setitimer.c +++ b/sysdeps/mach/hurd/setitimer.c @@ -339,6 +339,7 @@ __setitimer (enum __itimer_which which, const struct itimerval *new, struct itimerval *old) { void *crit; + int ret; switch (which) { @@ -353,9 +354,15 @@ __setitimer (enum __itimer_which which, const struct itimerval *new, break; } +retry: crit = _hurd_critical_section_lock (); __spin_lock (&_hurd_itimer_lock); - return setitimer_locked (new, old, crit, 0); + ret = setitimer_locked (new, old, crit, 0); + if (ret == -1 && errno == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; + + return ret; } static void diff --git a/sysdeps/mach/hurd/setregid.c b/sysdeps/mach/hurd/setregid.c index 2fce6cf..aad736e 100644 --- a/sysdeps/mach/hurd/setregid.c +++ b/sysdeps/mach/hurd/setregid.c @@ -28,6 +28,7 @@ __setregid (gid_t rgid, gid_t egid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -82,6 +83,9 @@ __setregid (gid_t rgid, gid_t egid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setresgid.c b/sysdeps/mach/hurd/setresgid.c index 8ccfd93..64b6840 100644 --- a/sysdeps/mach/hurd/setresgid.c +++ b/sysdeps/mach/hurd/setresgid.c @@ -29,6 +29,7 @@ __setresgid (gid_t rgid, gid_t egid, gid_t sgid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -110,6 +111,9 @@ __setresgid (gid_t rgid, gid_t egid, gid_t sgid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setresuid.c b/sysdeps/mach/hurd/setresuid.c index d16db17..53d07cc 100644 --- a/sysdeps/mach/hurd/setresuid.c +++ b/sysdeps/mach/hurd/setresuid.c @@ -29,6 +29,7 @@ __setresuid (uid_t ruid, uid_t euid, uid_t suid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -111,6 +112,9 @@ __setresuid (uid_t ruid, uid_t euid, uid_t suid) __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setreuid.c b/sysdeps/mach/hurd/setreuid.c index 97328e1..d093ed9 100644 --- a/sysdeps/mach/hurd/setreuid.c +++ b/sysdeps/mach/hurd/setreuid.c @@ -28,6 +28,7 @@ __setreuid (uid_t ruid, uid_t euid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -82,6 +83,9 @@ __setreuid (uid_t ruid, uid_t euid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/setsid.c b/sysdeps/mach/hurd/setsid.c index 3861f8f..698fc9c 100644 --- a/sysdeps/mach/hurd/setsid.c +++ b/sysdeps/mach/hurd/setsid.c @@ -32,6 +32,7 @@ __setsid (void) error_t err; unsigned int stamp; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_dtable_lock); @@ -60,6 +61,9 @@ __setsid (void) } HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; return err ? __hurd_fail (err) : _hurd_pgrp; } diff --git a/sysdeps/mach/hurd/setuid.c b/sysdeps/mach/hurd/setuid.c index ede3f01..4818357 100644 --- a/sysdeps/mach/hurd/setuid.c +++ b/sysdeps/mach/hurd/setuid.c @@ -32,6 +32,7 @@ __setuid (uid_t uid) auth_t newauth; error_t err; +retry: HURD_CRITICAL_BEGIN; __mutex_lock (&_hurd_id.lock); err = _hurd_check_ids (); @@ -86,6 +87,9 @@ __setuid (uid_t uid) } __mutex_unlock (&_hurd_id.lock); HURD_CRITICAL_END; + if (err == EINTR) + /* Got a signal while inside an RPC of the critical section, retry again */ + goto retry; if (err) return __hurd_fail (err); diff --git a/sysdeps/mach/hurd/spawni.c b/sysdeps/mach/hurd/spawni.c index 9bc1571..b5c9236 100644 --- a/sysdeps/mach/hurd/spawni.c +++ b/sysdeps/mach/hurd/spawni.c @@ -333,6 +333,7 @@ __spawni (pid_t *pid, const char *file, ss = _hurd_self_sigstate (); +retry: assert (! __spin_lock_locked (&ss->critical_section_lock)); __spin_lock (&ss->critical_section_lock); @@ -437,7 +438,19 @@ __spawni (pid_t *pid, const char *file, MACH_PORT_RIGHT_SEND, +1)); if (err) - goto out; + { + _hurd_critical_section_unlock (ss); + + if (err == EINTR) + { + /* Got a signal while inside an RPC of the critical section, retry again */ + __mach_port_deallocate (__mach_task_self (), auth); + auth = MACH_PORT_NULL; + goto retry; + } + + goto out; + } /* Pack up the descriptor table to give the new program. These descriptors will need to be reauthenticated below |