Move files to libpthread/ for inclusion along hurd

1 files changed, 213 insertions, 0 deletions

diff --git a/libpthread/sysdeps/l4/hurd/ia32/signal-dispatch-lowlevel.c b/libpthread/sysdeps/l4/hurd/ia32/signal-dispatch-lowlevel.c
new file mode 100644
index 00000000..37ef8215
--- /dev/null
+++ b/libpthread/sysdeps/l4/hurd/ia32/signal-dispatch-lowlevel.c
@@ -0,0 +1,213 @@
+/* signal-dispatch-lowlevel.c - ia32 specific signal handling functions.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   Written by Neal H. Walfield <neal@gnu.org>.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License
+   as published by the Free Software Foundation; either version 3 of
+   the License, or (at your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pt-internal.h>
+#include <sig-internal.h>
+
+#include <hurd/thread.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <atomic.h>
+
+extern char _signal_dispatch_entry;
+/* - 0(%esp) a pointer to the thread's struct signal_state.
+   - 4(%esp) a pointer to a siginfo_t.
+   - 8(%esp) is a pointer to the ss_flags field (or NULL).
+   - 12(%esp)+4 is the value of the sp when the thread was interrupted (intr_sp)
+     - 0(intr_sp) is the value of the ip when the thread was interrupted.
+   - 16(%esp) - 16 byte register save area
+*/
+__asm__ ("\n\
+	.globl _signal_dispatch_entry\n\
+_signal_dispatch_entry:\n\
+	/* Save caller saved registers (16 bytes).  */\n\
+	mov %eax, 16(%esp)\n\
+	mov %ecx, 16+4(%esp)\n\
+	mov %edx, 16+8(%esp)\n\
+	pushf\n\
+	popl %eax\n\
+	mov %eax, 16+12(%esp)\n\
+\n\
+	/* Reset EFLAGS.  */\n\
+	cld\n\
+	call signal_dispatch\n\
+\n\
+	/* Get the original stack and begin restoration.  */\n\
+	mov 12(%esp), %edx\n\
+\n\
+	/* Move the saved registers to the user stack.  */\n\
+	sub $16, %edx\n\
+	/* eax.  */\n\
+	mov 16+0(%esp), %ecx\n\
+	mov %ecx, 0(%edx)\n\
+	/* ecx.  */\n\
+	mov 16+4(%esp), %ecx\n\
+	mov %ecx, 4(%edx)\n\
+	/* edx.  */\n\
+	mov 16+8(%esp), %ecx\n\
+	mov %ecx, 8(%edx)\n\
+	/* eflags.  */\n\
+	mov 16+12(%esp), %ecx\n\
+	mov %ecx, 12(%edx)\n\
+\n\
+	/* Get the pointer to the sigaltstack flags.  */\n\
+	mov 8(%esp), %ecx\n\
+\n\
+	/* Restore the user stack.  */\n\
+	mov %edx, %esp\n\
+\n\
+	/* Clear the SA_ONSTACK flag.  */\n\
+	and %ecx, %ecx\n\
+	jz after_clear\n\
+	lock; and $~1, 0(%ecx)\n\
+after_clear:\n\
+\n\
+	/* Restore eflags, the scratch regs and the original sp and ip.  */\n\
+	popl %eax\n\
+	popl %ecx\n\
+	popl %edx\n\
+	popf\n\
+	ret\n");
+
+extern char _signal_dispatch_entry_self;
+/* - 0(%esp) is the return address (we ignore it)
+   - 4(%esp) is the sp to load
+
+   Since we are returning to signal_dispatch_lowlevel's caller, we
+   also need to restore its frame pointer.  */
+__asm__ ("\n\
+	.globl _signal_dispatch_entry_self\n\
+_signal_dispatch_entry_self:\n\
+	mov 0(%ebp), %ebp\n\
+	mov 4(%esp), %esp\n\
+	jmp _signal_dispatch_entry\n");
+
+void
+signal_dispatch_lowlevel (struct signal_state *ss, pthread_t tid,
+			  siginfo_t si)
+{
+  assert (pthread_mutex_trylock (&ss->lock) == EBUSY);
+
+  struct __pthread *thread = __pthread_getid (tid);
+
+  bool self = tid == pthread_self ();
+
+  uintptr_t intr_sp;
+
+  if (self)
+    {
+      /* The return address is just before the first argument.  */
+      intr_sp = (uintptr_t) &ss - 4;
+      assert (* (void **) intr_sp == __builtin_return_address (0));
+    }
+  else
+    {
+      struct hurd_thread_exregs_in in;
+      memset (&in, 0, sizeof (in));
+      struct hurd_thread_exregs_out out;
+
+      error_t err;
+      err = rm_thread_exregs (ADDR_VOID, thread->object,
+			      HURD_EXREGS_STOP | HURD_EXREGS_ABORT_IPC
+			      | HURD_EXREGS_GET_REGS,
+			      in, &out);
+      if (err)
+	panic ("Failed to modify thread " ADDR_FMT,
+	       ADDR_PRINTF (thread->object));
+
+      intr_sp = out.sp;
+
+      /* Push the ip on the user stack.  */
+      intr_sp -= 4;
+      * (uintptr_t *) intr_sp = out.ip;
+    }
+
+  bool altstack = false;
+  uintptr_t sp;
+  if (! (ss->actions[si.si_signo - 1].sa_flags & SA_ONSTACK)
+      || (ss->stack.ss_flags & SS_DISABLE)
+      || (ss->stack.ss_flags & SS_ONSTACK))
+    {
+      assert (! self);
+      sp = intr_sp;
+    }
+  else
+    {
+      /* The stack grows down.  */
+      sp = (uintptr_t) ss->stack.ss_sp + ss->stack.ss_size;
+
+      /* We know intimately that SS_ONSTACK is the least significant
+	 bit.  */
+      assert (SS_ONSTACK == 1);
+      atomic_bit_set (&ss->stack.ss_flags, 0);
+
+      altstack = true;
+    }
+
+  /* Set up the call frame for a call to signal_dispatch_entry.  */
+
+  /* Allocate a siginfo structure on the stack.  */
+  sp = sp - sizeof (siginfo_t);
+  siginfo_t *sip = (void *) sp;
+  /* Copy the user supplied values.  */
+  *sip = si;
+
+  /* Add space for the 4 caller saved registers.  */
+  sp -= 4 * sizeof (uintptr_t);
+
+  /* Save the interrupted sp.  */
+  sp -= 4;
+  * (uintptr_t *) sp = intr_sp;
+
+  /* Address of the ss_flags.  */
+  sp -= 4;
+  if (altstack)
+    * (uintptr_t *) sp = (uintptr_t) &ss->stack.ss_flags;
+  else
+    * (uintptr_t *) sp = 0;
+
+  /* Push the parameters to signal_dispatch.  */
+
+  /* signal info structure.  */
+  sp -= 4;
+  * (uintptr_t *) sp = (uintptr_t) sip;
+
+  /* The ss.  */
+  sp -= 4;
+  * (uintptr_t *) sp = (uintptr_t) ss;
+
+  pthread_mutex_transfer_np (&ss->lock, tid);
+
+  if (self)
+    ((void (*) (uintptr_t)) &_signal_dispatch_entry_self) ((uintptr_t) sp);
+  else
+    {
+      struct hurd_thread_exregs_in in;
+      struct hurd_thread_exregs_out out;
+
+      in.sp = sp;
+      in.ip = (uintptr_t) &_signal_dispatch_entry;
+
+      rm_thread_exregs (ADDR_VOID, thread->object,
+			HURD_EXREGS_SET_SP_IP
+			| HURD_EXREGS_START | HURD_EXREGS_ABORT_IPC,
+			in, &out);
+    }
+}