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/*--------------------------------------------------------------------*/
/*--- Create/destroy signal delivery frames. ---*/
/*--- sigframe-arm64-linux.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2013-2017 OpenWorks
info@open-works.net
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
The GNU General Public License is contained in the file COPYING.
*/
#if defined(VGP_arm64_linux)
#include "pub_core_basics.h"
#include "pub_core_vki.h"
#include "pub_core_threadstate.h"
#include "pub_core_aspacemgr.h"
#include "pub_core_libcbase.h"
#include "pub_core_libcassert.h"
#include "pub_core_libcprint.h"
#include "pub_core_machine.h"
#include "pub_core_options.h"
#include "pub_core_sigframe.h"
#include "pub_core_signals.h"
#include "pub_core_tooliface.h"
#include "pub_core_trampoline.h"
#include "priv_sigframe.h"
/* This uses the hack of dumping the vex guest state along with both
shadows in the frame, and restoring it afterwards from there,
rather than pulling it out of the ucontext. Then, integer
registers, the SP and the PC are restored from the ucontext. That
means that signal handlers which modify floating point registers or
in general any register state apart from X0-X30, XSP and PC in the
ucontext and then return, expecting their modifications to take
effect, will have those modifications ignored. */
/* This also always does the 'has siginfo' behaviour whether or
not it is requested. */
struct vg_sig_private {
UInt magicPI;
UInt sigNo_private;
VexGuestARM64State vex;
VexGuestARM64State vex_shadow1;
VexGuestARM64State vex_shadow2;
};
struct sigframe {
struct vki_ucontext uc;
unsigned long retcode[2];
struct vg_sig_private vp;
};
struct rt_sigframe {
vki_siginfo_t info;
struct sigframe sig;
};
static void synth_ucontext( ThreadId tid, const vki_siginfo_t *si,
UWord trapno, UWord err, const vki_sigset_t *set,
struct vki_ucontext *uc)
{
ThreadState *tst = VG_(get_ThreadState)(tid);
struct vki_sigcontext *sc = &uc->uc_mcontext;
VG_(memset)(uc, 0, sizeof(*uc));
uc->uc_flags = 0;
uc->uc_link = 0;
uc->uc_sigmask = *set;
uc->uc_stack = tst->altstack;
# define TO_CTX(reg) sc->regs[reg] = tst->arch.vex.guest_X##reg
TO_CTX(0); TO_CTX(1); TO_CTX(2); TO_CTX(3);
TO_CTX(4); TO_CTX(5); TO_CTX(6); TO_CTX(7);
TO_CTX(8); TO_CTX(9); TO_CTX(10); TO_CTX(11);
TO_CTX(12); TO_CTX(13); TO_CTX(14); TO_CTX(15);
TO_CTX(16); TO_CTX(17); TO_CTX(18); TO_CTX(19);
TO_CTX(20); TO_CTX(21); TO_CTX(22); TO_CTX(23);
TO_CTX(24); TO_CTX(25); TO_CTX(26); TO_CTX(27);
TO_CTX(28); TO_CTX(29); TO_CTX(30);
# undef TO_CTX
sc->sp = tst->arch.vex.guest_XSP;
sc->pc = tst->arch.vex.guest_PC;
sc->pstate = 0; /* slack .. could do better */
//sc->trap_no = trapno;
//sc->error_code = err;
sc->fault_address = (ULong)si->_sifields._sigfault._addr;
}
static void build_sigframe(ThreadState *tst,
struct sigframe *frame,
const vki_siginfo_t *siginfo,
const struct vki_ucontext *siguc,
void *handler, UInt flags,
const vki_sigset_t *mask,
void *restorer)
{
UWord trapno;
UWord err;
Int sigNo = siginfo->si_signo;
struct vg_sig_private *priv = &frame->vp;
VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, "signal handler frame",
(Addr)frame, offsetof(struct sigframe, vp));
if (siguc) {
trapno = 0; //siguc->uc_mcontext.trap_no;
err = 0; //siguc->uc_mcontext.error_code;
} else {
trapno = 0;
err = 0;
}
synth_ucontext(tst->tid, siginfo, trapno, err, mask, &frame->uc);
VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid,
(Addr)frame, offsetof(struct sigframe, vp));
priv->magicPI = 0x31415927;
priv->sigNo_private = sigNo;
priv->vex = tst->arch.vex;
priv->vex_shadow1 = tst->arch.vex_shadow1;
priv->vex_shadow2 = tst->arch.vex_shadow2;
}
/* EXPORTED */
void VG_(sigframe_create)( ThreadId tid,
Bool on_altstack,
Addr sp_top_of_frame,
const vki_siginfo_t *siginfo,
const struct vki_ucontext *siguc,
void *handler,
UInt flags,
const vki_sigset_t *mask,
void *restorer )
{
ThreadState *tst;
Addr sp = sp_top_of_frame;
Int sigNo = siginfo->si_signo;
UInt size;
tst = VG_(get_ThreadState)(tid);
size = sizeof(struct rt_sigframe);
sp -= size;
sp = VG_ROUNDDN(sp, 16);
if (! ML_(sf_maybe_extend_stack)(tst, sp, size, flags))
return; // Give up. No idea if this is correct
struct rt_sigframe *rsf = (struct rt_sigframe *)sp;
/* Track our writes to siginfo */
VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, /* VVVVV */
"signal handler siginfo", (Addr)rsf,
offsetof(struct rt_sigframe, sig));
VG_(memcpy)(&rsf->info, siginfo, sizeof(vki_siginfo_t));
if (sigNo == VKI_SIGILL && siginfo->si_code > 0) {
rsf->info._sifields._sigfault._addr
= (Addr*)(tst)->arch.vex.guest_PC;
}
VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, /* ^^^^^ */
(Addr)rsf, offsetof(struct rt_sigframe, sig));
build_sigframe(tst, &rsf->sig, siginfo, siguc,
handler, flags, mask, restorer);
tst->arch.vex.guest_X1 = (Addr)&rsf->info;
tst->arch.vex.guest_X2 = (Addr)&rsf->sig.uc;
VG_(set_SP)(tid, sp);
tst->arch.vex.guest_X0 = sigNo;
if (flags & VKI_SA_RESTORER)
tst->arch.vex.guest_X30 = (Addr)restorer;
else
tst->arch.vex.guest_X30
= (Addr)&VG_(arm64_linux_SUBST_FOR_rt_sigreturn);
tst->arch.vex.guest_PC = (Addr)handler;
VG_TRACK( post_reg_write, Vg_CoreSignal, tid,
VG_O_STACK_PTR, sizeof(Addr));
VG_TRACK( post_reg_write, Vg_CoreSignal, tid,
offsetof(VexGuestARM64State, guest_X0), sizeof(Addr));
VG_TRACK( post_reg_write, Vg_CoreSignal, tid,
offsetof(VexGuestARM64State, guest_X1), sizeof(Addr));
VG_TRACK( post_reg_write, Vg_CoreSignal, tid,
offsetof(VexGuestARM64State, guest_X2), sizeof(Addr));
VG_TRACK( post_reg_write, Vg_CoreSignal, tid,
offsetof(VexGuestARM64State, guest_X30), sizeof(Addr));
VG_TRACK( post_reg_write, Vg_CoreSignal, tid,
offsetof(VexGuestARM64State, guest_PC), sizeof(Addr));
}
/*------------------------------------------------------------*/
/*--- Destroying signal frames ---*/
/*------------------------------------------------------------*/
/* EXPORTED */
void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
{
vg_assert(VG_(is_valid_tid)(tid));
Bool has_siginfo = isRT;
ThreadState* tst = VG_(get_ThreadState)(tid);
Addr sp = tst->arch.vex.guest_XSP;
struct rt_sigframe* frame = (struct rt_sigframe *)sp;
struct vg_sig_private* priv = &frame->sig.vp;
vg_assert(priv->magicPI == 0x31415927);
tst->sig_mask = frame->sig.uc.uc_sigmask;
tst->tmp_sig_mask = tst->sig_mask;
Int sigNo = priv->sigNo_private;
UInt frame_size = sizeof(*frame);
/* Restore the entire machine state from our private copy. This
isn't really right, but we'll now move on to pick up at least
some changes that the signal handler may have made to the
sigcontext. */
tst->arch.vex = priv->vex;
tst->arch.vex_shadow1 = priv->vex_shadow1;
tst->arch.vex_shadow2 = priv->vex_shadow2;
if (has_siginfo) {
/* Pick up at least some state changes from the ucontext, just
in case the handler changed it. The shadow values will be
wrong, but hey. This restores the integer registers, the
program counter and stack pointer. FP/Vector regs, and any
condition code, FP status/control bits, etc, are not
restored. */
struct vki_sigcontext *sc =&frame->sig.uc.uc_mcontext;
# define FROM_CTX(reg) tst->arch.vex.guest_X##reg = sc->regs[reg]
FROM_CTX(0); FROM_CTX(1); FROM_CTX(2); FROM_CTX(3);
FROM_CTX(4); FROM_CTX(5); FROM_CTX(6); FROM_CTX(7);
FROM_CTX(8); FROM_CTX(9); FROM_CTX(10); FROM_CTX(11);
FROM_CTX(12); FROM_CTX(13); FROM_CTX(14); FROM_CTX(15);
FROM_CTX(16); FROM_CTX(17); FROM_CTX(18); FROM_CTX(19);
FROM_CTX(20); FROM_CTX(21); FROM_CTX(22); FROM_CTX(23);
FROM_CTX(24); FROM_CTX(25); FROM_CTX(26); FROM_CTX(27);
FROM_CTX(28); FROM_CTX(29); FROM_CTX(30);
# undef FROM_CTX
tst->arch.vex.guest_XSP = sc->sp; // should we use SET_SP here?
tst->arch.vex.guest_PC = sc->pc;
}
VG_TRACK( die_mem_stack_signal, sp - VG_STACK_REDZONE_SZB,
frame_size + VG_STACK_REDZONE_SZB );
if (VG_(clo_trace_signals))
VG_(message)(Vg_DebugMsg,
"VG_(sigframe_destroy) (thread %u): "
"isRT=%d valid magic; PC=%#llx\n",
tid, has_siginfo, tst->arch.vex.guest_PC);
/* tell the tools */
VG_TRACK( post_deliver_signal, tid, sigNo );
}
#endif // defined(VGP_arm_linux)
/*--------------------------------------------------------------------*/
/*--- end sigframe-arm64-linux.c ---*/
/*--------------------------------------------------------------------*/
|
