diff --git a/src/x86/Gresume.c b/src/x86/Gresume.c index e69de29b..faf0b527 100644 --- a/src/x86/Gresume.c +++ b/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 + +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 + +#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); +}