+Thu Aug 17 16:18:38 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>
+
+ * hurd/intr-msg.c: Use INTR_MSG_TRAP macro from machine-dependent
+ "intr-msg.h" for special syscall code, instead of i386-specific asm.
+ * hurd/hurdsig.c: Use INTR_MSG_BACK_OUT macro from
+ machine-dependent "intr-msg.h" before mutating thread state to
+ skip RPC.
+
+ * sysdeps/mach/hurd/i386/trampoline.c: If PC is inside
+ _hurd_intr_rpc_mach_msg special syscall code, use real SP saved in
+ %ecx.
+
+ * Makeconfig (link-libc): New variable; use shared library if
+ available.
+ (+link): Use it.
+
+ * sysdeps/mach/hurd/fork.c (_hurd_fork_locks): Variable removed.
+ Instead, declare with `symbol_set_declare'.
+ (fork): Use symbol_set_* macros for _hurd_fork_locks.
+ Use SS->thread instead of __mach_thread_self (). Suspend all
+ other threads during task_create and port copying.
+
Wed Aug 16 17:04:26 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>
* hurd/intr-msg.c: Fixed calculation of syscall %esp.
# Command for linking programs with the C library.
ifndef +link
-+link = $(CC) -nostdlib $(LDFLAGS) -o $@ \
++link = $(CC) -nostdlib -nostartfiles $(LDFLAGS) -o $@ \
$(addprefix $(csu-objpfx),start.o $(+preinit)) \
- $(^:lib=$(common-objpfx)libc.a) $(gnulib) $(common-objpfx)libc.a \
+ $(^:$(common-objpfx)libc.a=$(link-libc)) \
$(addprefix $(csu-objpfx),$(+postinit))
endif
+ifndef link-libc
+ifeq (yes,$(build-shared))
+link-libc = -L$(common-objdir) -lc $(gnulib)
+else
+link-libc = $(common-objpfx)libc.a $(gnulib) $(common-objpfx)libc.a
+endif
+endif
ifndef gnulib
gnulib := -lgcc
endif
return portloc;
}
-
+\f
+#include "intr-msg.h"
/* SS->thread is suspended.
mach_msg_type_name_t reply_port_type,
int untraced)
{
- extern const void _hurd_intr_rpc_msg_do_trap, _hurd_intr_rpc_msg_in_trap;
+ extern const void _hurd_intr_rpc_msg_in_trap;
mach_port_t rcv_port = MACH_PORT_NULL;
mach_port_t intr_port;
/* The thread is about to do the RPC, but hasn't yet entered
mach_msg. Mutate the thread's state so it knows not to try
the RPC. */
+ INTR_MSG_BACK_OUT (&state->basic);
MACHINE_THREAD_STATE_SET_PC (&state->basic,
&_hurd_intr_rpc_msg_in_trap);
state->basic.SYSRETURN = MACH_SEND_INTERRUPTED;
#include <mach/mig_errors.h>
#include <hurd/signal.h>
+#include "intr-msg.h"
+
+
error_t
_hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
mach_msg_option_t option,
ss->cancel = 0;
}
else
- /* err = intr_msg_trap (msg, option, send_size,
- rcv_size, rcv_name, timeout, notify);
- */
- asm (".globl _hurd_intr_rpc_msg_do_trap\n"
- ".globl _hurd_intr_rpc_msg_in_trap\n"
- " movl %%esp, %%ecx\n"
- " leal %1, %%esp\n"
- " movl $-25, %%eax\n"
- "_hurd_intr_rpc_msg_do_trap: lcall $7, $0 # status in %0\n"
- "_hurd_intr_rpc_msg_in_trap: movl %%ecx, %%esp"
- : "=a" (err) : "m" ((&msg)[-1]) : "%ecx");
+ err = INTR_MSG_TRAP (msg, option, send_size,
+ rcv_size, rcv_name, timeout, notify);
switch (err)
{
/* Things that want to be locked while forking. */
-struct
- {
- size_t n;
- struct mutex *locks[0];
- } _hurd_fork_locks;
+symbol_set_declare (_hurd_fork_locks)
/* Things that want to be called before we fork, to prepare the parent for
pid_t pid;
size_t i;
error_t err;
- thread_t thread_self = __mach_thread_self ();
struct hurd_sigstate *volatile ss;
ss = _hurd_self_sigstate ();
mach_msg_type_number_t nporttypes = 0;
thread_t *threads = NULL;
mach_msg_type_number_t nthreads = 0;
- int ports_locked = 0;
+ int ports_locked = 0, stopped = 0;
+
+ void resume_threads (void)
+ {
+ if (! stopped)
+ return;
+
+ assert (threads);
+
+ for (i = 0; i < nthreads; ++i)
+ if (threads[i] != ss->thread)
+ __thread_resume (threads[i]);
+ stopped = 0;
+ }
/* Run things that prepare for forking before we create the task. */
RUN_HOOK (_hurd_fork_prepare_hook, ());
/* Lock things that want to be locked before we fork. */
- for (i = 0; i < _hurd_fork_locks.n; ++i)
- __mutex_lock (_hurd_fork_locks.locks[i]);
+ {
+ void *const *p;
+ for (p = symbol_set_first_element (_hurd_fork_locks);
+ ! symbol_set_end_p (_hurd_fork_locks, p);
+ ++p)
+ __mutex_lock (*p);
+ }
__mutex_lock (&_hurd_siglock);
newtask = MACH_PORT_NULL;
__spin_lock (&_hurd_ports[i].lock);
ports_locked = 1;
- /* Create the child task. It will inherit a copy of our memory. */
- err = __task_create (__mach_task_self (), 1, &newtask);
+ /* Stop all other threads while copying the address space,
+ so nothing changes. */
+ err = __proc_dostop (_hurd_ports[INIT_PORT_PROC].port, ss->thread);
+ if (!err)
+ {
+ stopped = 1;
+
+ /* Create the child task. It will inherit a copy of our memory. */
+ err = __task_create (__mach_task_self (), 1, &newtask);
+ }
/* Unlock the global signal state lock, so we do not
block the signal thread any longer than necessary. */
if (err = __proc_task2proc (portnames[i], newtask, &insert))
LOSE;
}
- else if (portnames[i] == thread_self)
+ else if (portnames[i] == ss->thread)
{
/* For the name we use for our own thread port, we will
insert the thread port for the child main user thread
__spin_unlock (&_hurd_ports[i].lock);
ports_locked = 0;
+ /* All state has now been copied from the parent. It is safe to
+ resume other parent threads. */
+ resume_threads ();
+
/* Create the child main user thread and signal thread. */
if ((err = __thread_create (newtask, &thread)) ||
(err = __thread_create (newtask, &sigthread)))
dead name rights with the names we want to give the thread ports
in the child as placeholders. Now deallocate them so we can use
the names. */
- if ((err = __mach_port_deallocate (newtask, thread_self)) ||
- (err = __mach_port_insert_right (newtask, thread_self,
+ if ((err = __mach_port_deallocate (newtask, ss->thread)) ||
+ (err = __mach_port_insert_right (newtask, ss->thread,
thread, MACH_MSG_TYPE_COPY_SEND)))
LOSE;
/* We have one extra user reference created at the beginning of this
accounted for in the child below). This extra right gets consumed
in the child by the store into _hurd_sigthread in the child fork. */
if (thread_refs > 1 &&
- (err = __mach_port_mod_refs (newtask, thread_self,
+ (err = __mach_port_mod_refs (newtask, ss->thread,
MACH_PORT_RIGHT_SEND,
- thread_refs - 1)))
+ thread_refs)))
LOSE;
if ((_hurd_msgport_thread != MACH_PORT_NULL) /* Let user have none. */
&& ((err = __mach_port_deallocate (newtask, _hurd_msgport_thread)) ||
for (i = 0; i < _hurd_nports; ++i)
__spin_unlock (&_hurd_ports[i].lock);
+ resume_threads ();
+
if (newtask != MACH_PORT_NULL)
{
if (err)
__mach_port_deallocate (__mach_task_self (), sigthread);
if (newproc != MACH_PORT_NULL)
__mach_port_deallocate (__mach_task_self (), newproc);
- if (thread_self != MACH_PORT_NULL)
- __mach_port_deallocate (__mach_task_self (), thread_self);
if (portnames)
__vm_deallocate (__mach_task_self (),
/* We are the only thread in this new task, so we will
take the task-global signals. */
- _hurd_sigthread = thread_self;
+ _hurd_sigthread = ss->thread;
/* Unchain the sigstate structures for threads that existed in the
parent task but don't exist in this task (the child process).
/* Unlock things we locked before creating the child task.
They are locked in both the parent and child tasks. */
- for (i = 0; i < _hurd_fork_locks.n; ++i)
- __mutex_unlock (_hurd_fork_locks.locks[i]);
+ {
+ void *const *p;
+ for (p = symbol_set_first_element (_hurd_fork_locks);
+ ! symbol_set_end_p (_hurd_fork_locks, p);
+ ++p)
+ __mutex_unlock (*p);
+ }
_hurd_critical_section_unlock (ss);
struct machine_thread_all_state *state)
{
__label__ trampoline, rpc_wait_trampoline, firewall;
+ extern const void _hurd_intr_rpc_msg_in_trap;
+ extern const void _hurd_intr_rpc_msg_cx_sp;
+ extern const void _hurd_intr_rpc_msg_sp_restored;
void *volatile sigsp;
struct sigcontext *scp;
struct
if (! machine_get_basic_state (ss->thread, state))
return NULL;
+ /* Save the original SP in the gratuitous `esp' slot.
+ We may need to reset the SP (the `uesp' slot) to avoid clobbering an
+ interrupted RPC frame. */
+ state->basic.esp = state->basic.uesp;
+
if ((ss->actions[signo].sa_flags & SA_ONSTACK) &&
!(ss->sigaltstack.ss_flags & (SA_DISABLE|SA_ONSTACK)))
{
/* XXX need to set up base of new stack for
per-thread variables, cthreads. */
}
+ /* This code has intimate knowledge of the special mach_msg system call
+ done in intr-msg.c; that code does:
+ movl %esp, %ecx
+ leal ARGS, %esp
+ _hurd_intr_rpc_msg_cx_sp: movl $-25, %eax
+ _hurd_intr_rpc_msg_do_trap: lcall $7, $0
+ _hurd_intr_rpc_msg_in_trap: movl %ecx, %esp
+ _hurd_intr_rpc_msg_sp_restored:
+ We must check for the window during which %esp points at the
+ mach_msg arguments. The space below until %ecx is used by
+ the _hurd_intr_rpc_mach_msg frame, and must not be clobbered. */
+ else if (state->basic.eip >= (int) &_hurd_intr_rpc_msg_cx_sp &&
+ state->basic.eip < (int) &_hurd_intr_rpc_msg_sp_restored)
+ /* The SP now points at the mach_msg args, but there is more stack
+ space used below it. The real SP is saved in %ecx; we must push the
+ new frame below there, and restore that value as the SP on
+ sigreturn. */
+ sigsp = (char *) (state->basic.uesp = state->basic.ecx);
else
sigsp = (char *) state->basic.uesp;
message reception, since the request message has already been
sent. */
- struct mach_msg_trap_args *args = (void *) state->basic.uesp;
+ struct mach_msg_trap_args *args = (void *) state->basic.esp;
if (_hurdsig_catch_fault (SIGSEGV))
{
state->basic.eip = (int) &&rpc_wait_trampoline;
/* The reply-receiving trampoline code runs initially on the original
user stack. We pass it the signal stack pointer in %ebx. */
+ state->basic.uesp = state->basic.esp; /* Restore mach_msg syscall SP. */
state->basic.ebx = (int) sigsp;
/* After doing the message receive, the trampoline code will need to
update the %eax value to be restored by sigreturn. To simplify
git://sourceware.org / glibc.git / commitdiff