$NetBSD$ --- coregrind/m_sigframe/sigframe-amd64-netbsd.c.orig 2019-03-30 07:21:10.160474699 +0000 +++ coregrind/m_sigframe/sigframe-amd64-netbsd.c @@ -0,0 +1,625 @@ + +/*--------------------------------------------------------------------*/ +/*--- Create/destroy signal delivery frames. ---*/ +/*--- sigframe-x86-nebsdelf2.c ---*/ +/*--------------------------------------------------------------------*/ + +/* + This file is part of Valgrind, a dynamic binary instrumentation + framework. + + Copyright (C) 2000-2005 Nicholas Nethercote + njn@valgrind.org + + 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307, USA. + + The GNU General Public License is contained in the file COPYING. +*/ + +#if defined(VGP_amd64_netbsd) + +#include "pub_core_basics.h" +#include "pub_core_vki.h" +#include "pub_core_libcsetjmp.h" // to keep _threadstate.h happy +#include "pub_core_threadstate.h" +#include "pub_core_aspacemgr.h" /* find_segment */ +#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" + + +/* This module creates and removes signal frames for signal deliveries + on x86-linux. + + Note, this file contains kernel-specific knowledge in the form of + 'struct sigframe' and 'struct rt_sigframe'. How does that relate + to the vki kernel interface stuff? + + Either a 'struct sigframe' or a 'struct rtsigframe' is pushed + onto the client's stack. This contains a subsidiary + vki_ucontext. That holds the vcpu's state across the signal, + so that the sighandler can mess with the vcpu state if it + really wants. + + FIXME: sigcontexting is basically broken for the moment. When + delivering a signal, the integer registers and %eflags are + correctly written into the sigcontext, however the FP and SSE state + is not. When returning from a signal, only the integer registers + are restored from the sigcontext; the rest of the CPU state is + restored to what it was before the signal. + + This will be fixed. +*/ + + +/*------------------------------------------------------------*/ +/*--- Signal frame layouts ---*/ +/*------------------------------------------------------------*/ + +// A structure in which to save the application's registers +// during the execution of signal handlers. + +// Linux has 2 signal frame structures: one for normal signal +// deliveries, and one for SA_SIGINFO deliveries (also known as RT +// signals). +// +// In theory, so long as we get the arguments to the handler function +// right, it doesn't matter what the exact layout of the rest of the +// frame is. Unfortunately, things like gcc's exception unwinding +// make assumptions about the locations of various parts of the frame, +// so we need to duplicate it exactly. + +/* Valgrind-specific parts of the signal frame */ +struct vg_sigframe +{ + /* Sanity check word. */ + UInt magicPI; + + UInt handlerflags; /* flags for signal handler */ + + + /* Safely-saved version of sigNo, as described above. */ + Int sigNo_private; + + /* XXX This is wrong. Surely we should store the shadow values + into the shadow memory behind the actual values? */ + VexGuestAMD64State vex_shadow1; + VexGuestAMD64State vex_shadow2; + + /* HACK ALERT */ + VexGuestAMD64State vex; + /* end HACK ALERT */ + + /* saved signal mask to be restored when handler returns */ + vki_sigset_t mask; + + /* Sanity check word. Is the highest-addressed word; do not + move!*/ + UInt magicE; +}; + +struct sigframe +{ + /* Sig handler's return address */ + Addr retaddr; + Int sigNo; + +/* struct vki_sigcontext sigContext; */ + struct vki_mcontext sigContext; /* XXX - netbsd */ +// struct _vki_fpstate fpstate; + + struct vg_sigframe vg; +}; + + +//:: /*------------------------------------------------------------*/ +//:: /*--- Signal operations ---*/ +//:: /*------------------------------------------------------------*/ +//:: +//:: /* +//:: Great gobs of FP state conversion taken wholesale from +//:: linux/arch/i386/kernel/i387.c +//:: */ +//:: +//:: /* +//:: * FXSR floating point environment conversions. +//:: */ +//:: #define X86_FXSR_MAGIC 0x0000 +//:: +//:: /* +//:: * FPU tag word conversions. +//:: */ +//:: +//:: static inline unsigned short twd_i387_to_fxsr( unsigned short twd ) +//:: { +//:: unsigned int tmp; /* to avoid 16 bit prefixes in the code */ +//:: +//:: /* Transform each pair of bits into 01 (valid) or 00 (empty) */ +//:: tmp = ~twd; +//:: tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */ +//:: /* and move the valid bits to the lower byte. */ +//:: tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */ +//:: tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */ +//:: tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */ +//:: return tmp; +//:: } +//:: +//:: static unsigned long twd_fxsr_to_i387( const struct i387_fxsave_struct *fxsave ) +//:: { +//:: struct _vki_fpxreg *st = NULL; +//:: unsigned long twd = (unsigned long) fxsave->twd; +//:: unsigned long tag; +//:: unsigned long ret = 0xffff0000u; +//:: int i; +//:: +//:: #define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16); +//:: +//:: for ( i = 0 ; i < 8 ; i++ ) { +//:: if ( twd & 0x1 ) { +//:: st = (struct _vki_fpxreg *) FPREG_ADDR( fxsave, i ); +//:: +//:: switch ( st->exponent & 0x7fff ) { +//:: case 0x7fff: +//:: tag = 2; /* Special */ +//:: break; +//:: case 0x0000: +//:: if ( !st->significand[0] && +//:: !st->significand[1] && +//:: !st->significand[2] && +//:: !st->significand[3] ) { +//:: tag = 1; /* Zero */ +//:: } else { +//:: tag = 2; /* Special */ +//:: } +//:: break; +//:: default: +//:: if ( st->significand[3] & 0x8000 ) { +//:: tag = 0; /* Valid */ +//:: } else { +//:: tag = 2; /* Special */ +//:: } +//:: break; +//:: } +//:: } else { +//:: tag = 3; /* Empty */ +//:: } +//:: ret |= (tag << (2 * i)); +//:: twd = twd >> 1; +//:: } +//:: return ret; +//:: } +//:: +//:: static void convert_fxsr_to_user( struct _vki_fpstate *buf, +//:: const struct i387_fxsave_struct *fxsave ) +//:: { +//:: unsigned long env[7]; +//:: struct _vki_fpreg *to; +//:: struct _vki_fpxreg *from; +//:: int i; +//:: +//:: env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul; +//:: env[1] = (unsigned long)fxsave->swd | 0xffff0000ul; +//:: env[2] = twd_fxsr_to_i387(fxsave); +//:: env[3] = fxsave->fip; +//:: env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16); +//:: env[5] = fxsave->foo; +//:: env[6] = fxsave->fos; +//:: +//:: VG_(memcpy)(buf, env, 7 * sizeof(unsigned long)); +//:: +//:: to = &buf->_st[0]; +//:: from = (struct _vki_fpxreg *) &fxsave->st_space[0]; +//:: for ( i = 0 ; i < 8 ; i++, to++, from++ ) { +//:: unsigned long __user *t = (unsigned long __user *)to; +//:: unsigned long *f = (unsigned long *)from; +//:: +//:: t[0] = f[0]; +//:: t[1] = f[1]; +//:: to->exponent = from->exponent; +//:: } +//:: } +//:: +//:: static void convert_fxsr_from_user( struct i387_fxsave_struct *fxsave, +//:: const struct _vki_fpstate *buf ) +//:: { +//:: unsigned long env[7]; +//:: struct _vki_fpxreg *to; +//:: const struct _vki_fpreg *from; +//:: int i; +//:: +//:: VG_(memcpy)(env, buf, 7 * sizeof(long)); +//:: +//:: fxsave->cwd = (unsigned short)(env[0] & 0xffff); +//:: fxsave->swd = (unsigned short)(env[1] & 0xffff); +//:: fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff)); +//:: fxsave->fip = env[3]; +//:: fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16); +//:: fxsave->fcs = (env[4] & 0xffff); +//:: fxsave->foo = env[5]; +//:: fxsave->fos = env[6]; +//:: +//:: to = (struct _vki_fpxreg *) &fxsave->st_space[0]; +//:: from = &buf->_st[0]; +//:: for ( i = 0 ; i < 8 ; i++, to++, from++ ) { +//:: unsigned long *t = (unsigned long *)to; +//:: unsigned long __user *f = (unsigned long __user *)from; +//:: +//:: t[0] = f[0]; +//:: t[1] = f[1]; +//:: to->exponent = from->exponent; +//:: } +//:: } +//:: +//:: static inline void save_i387_fsave( arch_thread_t *regs, struct _vki_fpstate *buf ) +//:: { +//:: struct i387_fsave_struct *fs = ®s->m_sse.fsave; +//:: +//:: fs->status = fs->swd; +//:: VG_(memcpy)(buf, fs, sizeof(*fs)); +//:: } +//:: +//:: static void save_i387_fxsave( arch_thread_t *regs, struct _vki_fpstate *buf ) +//:: { +//:: const struct i387_fxsave_struct *fx = ®s->m_sse.fxsave; +//:: convert_fxsr_to_user( buf, fx ); +//:: +//:: buf->status = fx->swd; +//:: buf->magic = X86_FXSR_MAGIC; +//:: VG_(memcpy)(buf->_fxsr_env, fx, sizeof(struct i387_fxsave_struct)); +//:: } +//:: +//:: static void save_i387( arch_thread_t *regs, struct _vki_fpstate *buf ) +//:: { +//:: if ( VG_(have_ssestate) ) +//:: save_i387_fxsave( regs, buf ); +//:: else +//:: save_i387_fsave( regs, buf ); +//:: } +//:: +//:: static inline void restore_i387_fsave( arch_thread_t *regs, const struct _vki_fpstate __user *buf ) +//:: { +//:: VG_(memcpy)( ®s->m_sse.fsave, buf, sizeof(struct i387_fsave_struct) ); +//:: } +//:: +//:: static void restore_i387_fxsave( arch_thread_t *regs, const struct _vki_fpstate __user *buf ) +//:: { +//:: VG_(memcpy)(®s->m_sse.fxsave, &buf->_fxsr_env[0], +//:: sizeof(struct i387_fxsave_struct) ); +//:: /* mxcsr reserved bits must be masked to zero for security reasons */ +//:: regs->m_sse.fxsave.mxcsr &= 0xffbf; +//:: convert_fxsr_from_user( ®s->m_sse.fxsave, buf ); +//:: } +//:: +//:: static void restore_i387( arch_thread_t *regs, const struct _vki_fpstate __user *buf ) +//:: { +//:: if ( VG_(have_ssestate) ) { +//:: restore_i387_fxsave( regs, buf ); +//:: } else { +//:: restore_i387_fsave( regs, buf ); +//:: } +//:: } + + +/*------------------------------------------------------------*/ +/*--- Creating signal frames ---*/ +/*------------------------------------------------------------*/ + +/* Create a plausible-looking sigcontext from the thread's + Vex guest state. NOTE: does not fill in the FP or SSE + bits of sigcontext at the moment. +*/ +/* static */ +/* void synth_ucontext(ThreadId tid, const vki_siginfo_t *si, */ +/* const vki_sigset_t *set, */ +/* struct vki_ucontext *uc, struct _vki_fpstate *fpstate) */ +/* { */ +/* 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; */ +/* sc->fpstate = fpstate; */ + +/* // FIXME: save_i387(&tst->arch, fpstate); */ + +/* # define SC2(reg,REG) sc->reg = tst->arch.vex.guest_##REG */ +/* SC2(gs,GS); */ +/* SC2(fs,FS); */ +/* SC2(es,ES); */ +/* SC2(ds,DS); */ + +/* SC2(edi,EDI); */ +/* SC2(esi,ESI); */ +/* SC2(ebp,EBP); */ +/* SC2(esp,ESP); */ +/* SC2(ebx,EBX); */ +/* SC2(edx,EDX); */ +/* SC2(ecx,ECX); */ +/* SC2(eax,EAX); */ + +/* SC2(eip,EIP); */ +/* SC2(cs,CS); */ +/* sc->eflags = LibVEX_GuestX86_get_eflags(&tst->arch.vex); */ +/* SC2(ss,SS); */ +/* /\* XXX esp_at_signal *\/ */ +/* /\* XXX trapno *\/ */ +/* /\* XXX err *\/ */ +/* # undef SC2 */ + +/* sc->cr2 = (UInt)si->_sifields._sigfault._addr; */ + +/* } */ + + +/* Extend the stack segment downwards if needed so as to ensure the + new signal frames are mapped to something. Return a Bool + indicating whether or not the operation was successful. +*/ +/* static Bool extend ( ThreadState *tst, Addr addr, SizeT size ) */ +/* { */ +/* ThreadId tid = tst->tid; */ +/* NSegment *stackseg = NULL; */ + +/* if (VG_(extend_stack)(addr, tst->client_stack_szB)) { */ +/* stackseg = VG_(am_find_nsegment)(addr); */ +/* if (0 && stackseg) */ +/* VG_(printf)("frame=%p seg=%p-%p\n", */ +/* addr, stackseg->start, stackseg->end); */ +/* } */ + +/* if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) { */ +/* VG_(message)( */ +/* Vg_UserMsg, */ +/* "Can't extend stack to %p during signal delivery for thread %d:", */ +/* addr, tid); */ +/* if (stackseg == NULL) */ +/* VG_(message)(Vg_UserMsg, " no stack segment"); */ +/* else */ +/* VG_(message)(Vg_UserMsg, " too small or bad protection modes"); */ + +/* /\* set SIGSEGV to default handler *\/ */ +/* VG_(set_default_handler)(VKI_SIGSEGV); */ +/* VG_(synth_fault_mapping)(tid, addr); */ + +/* /\* The whole process should be about to die, since the default */ +/* action of SIGSEGV to kill the whole process. *\/ */ +/* return False; */ +/* } */ + +/* /\* For tracking memory events, indicate the entire frame has been */ +/* allocated. *\/ */ +/* VG_TRACK( new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB, */ +/* size + VG_STACK_REDZONE_SZB ); */ + +/* return True; */ +/* } */ + + +/* Build the Valgrind-specific part of a signal frame. */ + +/* static void build_vg_sigframe(struct vg_sigframe *frame, */ +/* ThreadState *tst, */ +/* const vki_sigset_t *mask, */ +/* UInt flags, */ +/* Int sigNo) */ +/* { */ +/* frame->sigNo_private = sigNo; */ +/* frame->magicPI = 0x31415927; */ +/* frame->vex_shadow = tst->arch.vex_shadow; */ +/* /\* HACK ALERT *\/ */ +/* frame->vex = tst->arch.vex; */ +/* /\* end HACK ALERT *\/ */ +/* frame->mask = tst->sig_mask; */ +/* frame->handlerflags = flags; */ +/* frame->magicE = 0x27182818; */ +/* } */ + + +static Addr build_sigframe(ThreadState *tst, + Addr esp_top_of_frame, + const vki_siginfo_t *siginfo, + void *handler, UInt flags, + const vki_sigset_t *mask, + void *restorer) +{ +/* struct sigframe *frame; */ +/* Addr esp = esp_top_of_frame; */ +/* Int sigNo = siginfo->si_signo; */ +/* struct vki_ucontext uc; */ + +/* vg_assert((flags & VKI_SA_SIGINFO) == 0); */ + +/* esp -= sizeof(*frame); */ +/* esp = VG_ROUNDDN(esp, 16); */ +/* frame = (struct sigframe *)esp; */ + +/* if (!extend(tst, esp, sizeof(*frame))) */ +/* return esp_top_of_frame; */ + +/* /\* retaddr, sigNo, siguContext fields are to be written *\/ */ +/* VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, "signal handler frame", */ +/* esp, offsetof(struct sigframe, vg) ); */ + +/* frame->sigNo = sigNo; */ + +/* if (flags & VKI_SA_RESTORER) */ +/* frame->retaddr = (Addr)restorer; */ +/* else */ +/* frame->retaddr = (Addr)&VG_(x86_netbsdelf2_SUBST_FOR_sigreturn); */ + +/* synth_ucontext(tst->tid, siginfo, mask, &uc, &frame->fpstate); */ + +/* VG_(memcpy)(&frame->sigContext, &uc.uc_mcontext, */ +/* sizeof(struct vki_sigcontext)); */ +/* frame->sigContext.oldmask = mask->sig[0]; */ + +/* VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, */ +/* esp, offsetof(struct sigframe, vg) ); */ + +/* build_vg_sigframe(&frame->vg, tst, mask, flags, sigNo); */ + +/* return esp; */ + I_die_here; +} + +/* EXPORTED */ +void VG_(sigframe_create)( ThreadId tid, + Bool on_altstack, + Addr rsp_top_of_frame, + const vki_siginfo_t *siginfo, + const struct vki_ucontext *siguc, + void *handler, + UInt flags, + const vki_sigset_t *mask, + void *restorer ) +{ + Addr esp; + ThreadState* tst = VG_(get_ThreadState)(tid); + + esp = build_sigframe(tst, rsp_top_of_frame, + siginfo, handler, flags, mask, restorer); + + /* Set the thread so it will next run the handler. */ + /* tst->m_esp = esp; also notify the tool we've updated ESP */ + VG_(set_SP)(tid, esp); + VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR, sizeof(Addr)); + + //VG_(printf)("handler = %p\n", handler); + tst->arch.vex.guest_RIP = (Addr) handler; + /* This thread needs to be marked runnable, but we leave that the + caller to do. */ + + if (0) + VG_(printf)("pushed signal frame; %%RSP now = %p, " + "next %%RIP = %p, status=%d\n", + esp, tst->arch.vex.guest_RIP, tst->status); +} + + +/*------------------------------------------------------------*/ +/*--- Destroying signal frames ---*/ +/*------------------------------------------------------------*/ + +/* Return False and don't do anything, just set the client to take a + segfault, if it looks like the frame is corrupted. */ +static +Bool restore_vg_sigframe ( ThreadState *tst, + struct vg_sigframe *frame, Int *sigNo ) +{ + if (frame->magicPI != 0x31415927 || + frame->magicE != 0x27182818) { + VG_(message)(Vg_UserMsg, "Thread %d return signal frame " + "corrupted. Killing process.", + tst->tid); + VG_(set_default_handler)(VKI_SIGSEGV); + VG_(synth_fault)(tst->tid); + *sigNo = VKI_SIGSEGV; + return False; + } + tst->sig_mask = frame->mask; + tst->tmp_sig_mask = frame->mask; +// tst->arch.vex_shadow = frame->vex_shadow; + /* HACK ALERT */ + tst->arch.vex = frame->vex; + /* end HACK ALERT */ + *sigNo = frame->sigNo_private; + return True; +} + +static +void restore_sigcontext( ThreadState *tst, + struct vki_mcontext *sc, /* was sigcontext */ + struct _vki_fpstate *fpstate ) +{ +/* tst->arch.vex.guest_EAX = sc->eax; */ +/* tst->arch.vex.guest_ECX = sc->ecx; */ +/* tst->arch.vex.guest_EDX = sc->edx; */ +/* tst->arch.vex.guest_EBX = sc->ebx; */ +/* tst->arch.vex.guest_EBP = sc->ebp; */ +/* tst->arch.vex.guest_ESP = sc->esp; */ +/* tst->arch.vex.guest_ESI = sc->esi; */ +/* tst->arch.vex.guest_EDI = sc->edi; */ +/* //:: tst->arch.vex.guest_eflags = sc->eflags; */ +/* //:: tst->arch.vex.guest_RIP = sc->eip; */ + +/* tst->arch.vex.guest_CS = sc->cs; */ +/* tst->arch.vex.guest_SS = sc->ss; */ +/* tst->arch.vex.guest_DS = sc->ds; */ +/* tst->arch.vex.guest_ES = sc->es; */ +/* tst->arch.vex.guest_FS = sc->fs; */ +/* tst->arch.vex.guest_GS = sc->gs; */ + +/* //:: restore_i387(&tst->arch, fpstate); */ + I_die_here; +} + + +static +SizeT restore_sigframe ( ThreadState *tst, + struct sigframe *frame, Int *sigNo ) +{ +// if (restore_vg_sigframe(tst, &frame->vg, sigNo)) +// restore_sigcontext(tst, &frame->sigContext, &frame->fpstate); + + return sizeof(*frame); +} + + +/* EXPORTED */ +void VG_(sigframe_destroy)( ThreadId tid ) +{ + Bool isRT; + memset(&isRT, 0, sizeof(isRT)); + Addr rsp; + ThreadState* tst; + SizeT size; + Int sigNo; + + tst = VG_(get_ThreadState)(tid); + + /* Correctly reestablish the frame base address. */ + rsp = tst->arch.vex.guest_RSP; + + size = restore_sigframe(tst, (struct sigframe *)rsp, &sigNo); + + VG_TRACK( die_mem_stack_signal, rsp - VG_STACK_REDZONE_SZB, + size + VG_STACK_REDZONE_SZB ); + + if (VG_(clo_trace_signals)) + VG_(message)( + Vg_DebugMsg, + "VG_(signal_return) (thread %d): isRT=%d valid magic; RIP=%p", + tid, isRT, tst->arch.vex.guest_RIP); + + /* tell the tools */ + VG_TRACK( post_deliver_signal, tid, sigNo ); +} + +#endif + +/*--------------------------------------------------------------------*/ +/*--- end sigframe-x86-netbsdelf2.c ---*/ +/*--------------------------------------------------------------------*/