Rename: src/x86/Gresume-x86.c -> src/x86/Gresume.c

(Logical change 1.241)

src/x86/Gresume.c

@@ -0,0 +1,154 @@
+/* libunwind - a platform-independent unwind library
+   Copyright (c) 2002-2004 Hewlett-Packard Development Company, L.P.
+	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
+
+This file is part of libunwind.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+
+#include <stdlib.h>
+
+#include "unwind_i.h"
+
+#ifndef UNW_REMOTE_ONLY
+
+HIDDEN inline int
+x86_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
+{
+#if defined(__linux)
+  struct cursor *c = (struct cursor *) cursor;
+  ucontext_t *uc = c->dwarf.as_arg;
+
+  /* Ensure c->pi is up-to-date.  On x86, it's relatively common to be
+     missing DWARF unwind info.  We don't want to fail in that case,
+     because the frame-chain still would let us do a backtrace at
+     least.  */
+  dwarf_make_proc_info (&c->dwarf);
+
+  if (unlikely (c->sigcontext_format != X86_SCF_NONE))
+    {
+      struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
+
+#if 0
+      /* We're returning to a frame that was (either directly or
+	 indirectly) interrupted by a signal.  We have to restore
+	 _both_ "preserved" and "scratch" registers.  That doesn't
+	 leave us any registers to work with, and the only way we can
+	 achieve this is by doing a sigreturn().
+
+	 Note: it might be tempting to think that we don't have to
+	 restore the scratch registers when returning to a frame that
+	 was indirectly interrupted by a signal.  However, that is not
+	 safe because that frame and its descendants could have been
+	 using a special convention that stores "preserved" state in
+	 scratch registers.  For example, the Linux fsyscall
+	 convention does this with r11 (to save ar.pfs) and b6 (to
+	 save "rp"). */
+
+      sc->sc_gr[12] = c->psp;
+      c->psp = c->sigcontext_addr - c->sigcontext_off;
+
+      /* Clear the "in-syscall" flag, because in general we won't be
+	 returning to the interruption-point and we need all registers
+	 restored.  */
+      sc->sc_flags &= ~IA64_SC_FLAG_IN_SYSCALL;
+      sc->sc_ip = c->ip;
+      sc->sc_cfm = c->cfm & (((unw_word_t) 1 << 38) - 1);
+      sc->sc_pr = (c->pr & ~PR_SCRATCH) | (sc->sc_pr & ~PR_PRESERVED);
+      if ((ret = ia64_get (c, c->loc[IA64_REG_PFS], &sc->sc_ar_pfs)) < 0
+	  || (ret = ia64_get (c, c->loc[IA64_REG_FPSR], &sc->sc_ar_fpsr)) < 0
+	  || (ret = ia64_get (c, c->loc[IA64_REG_UNAT], &sc->sc_ar_unat)) < 0)
+	return ret;
+
+      sc->sc_gr[1] = c->pi.gp;
+      if (c->eh_valid_mask & 0x1) sc->sc_gr[15] = c->eh_args[0];
+      if (c->eh_valid_mask & 0x2) sc->sc_gr[16] = c->eh_args[1];
+      if (c->eh_valid_mask & 0x4) sc->sc_gr[17] = c->eh_args[2];
+      if (c->eh_valid_mask & 0x8) sc->sc_gr[18] = c->eh_args[3];
+#endif
+
+      Debug (9, "resuming at ip=%x via sigreturn(%p)\n", c->dwarf.ip, sc);
+      sigreturn (sc);
+    }
+  else
+    {
+      Debug (9, "resuming at ip=%x via setcontext()\n", c->dwarf.ip);
+      setcontext (uc);
+    }
+#else
+# warning Implement me!
+#endif
+  return -UNW_EINVAL;
+}
+
+#endif /* !UNW_REMOTE_ONLY */
+
+/* This routine is responsible for copying the register values in
+   cursor C and establishing them as the current machine state. */
+
+static inline int
+establish_machine_state (struct cursor *c)
+{
+  int (*access_reg) (unw_addr_space_t, unw_regnum_t, unw_word_t *,
+		     int write, void *);
+  int (*access_fpreg) (unw_addr_space_t, unw_regnum_t, unw_fpreg_t *,
+		       int write, void *);
+  unw_addr_space_t as = c->dwarf.as;
+  void *arg = c->dwarf.as_arg;
+  unw_fpreg_t fpval;
+  unw_word_t val;
+  int reg;
+
+  access_reg = as->acc.access_reg;
+  access_fpreg = as->acc.access_fpreg;
+
+  Debug (8, "copying out cursor state\n");
+
+  for (reg = 0; reg < UNW_REG_LAST; ++reg)
+    {
+Debug (16, "copying %s\n", unw_regname (reg));
+      if (unw_is_fpreg (reg))
+	{
+	  if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
+	    (*access_fpreg) (as, reg, &fpval, 1, arg);
+	}
+      else
+	{
+	  if (tdep_access_reg (c, reg, &val, 0) >= 0)
+	    (*access_reg) (as, reg, &val, 1, arg);
+	}
+    }
+  return 0;
+}
+
+PROTECTED int
+unw_resume (unw_cursor_t *cursor)
+{
+  struct cursor *c = (struct cursor *) cursor;
+  int ret;
+
+  Debug (2, "(cursor=%p)\n", c);
+
+  if ((ret = establish_machine_state (c)) < 0)
+    return ret;
+
+  return (*c->dwarf.as->acc.resume) (c->dwarf.as, (unw_cursor_t *) c,
+				     c->dwarf.as_arg);
+}