| |
| /*--------------------------------------------------------------------*/ |
| /*--- Create/destroy signal delivery frames. ---*/ |
| /*--- sigframe-ppc64-linux.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2000-2013 Nicholas Nethercote |
| njn@valgrind.org |
| Copyright (C) 2004-2013 Paul Mackerras |
| paulus@samba.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_ppc64be_linux) || defined(VGP_ppc64le_linux) |
| |
| #include "pub_core_basics.h" |
| #include "pub_core_vki.h" |
| #include "pub_core_vkiscnums.h" |
| #include "pub_core_libcsetjmp.h" // to keep _threadstate.h happy |
| #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 "pub_core_transtab.h" // VG_(discard_translations) |
| |
| |
| /* This module creates and removes signal frames for signal deliveries |
| on ppc64-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. |
| |
| // On ppc64-linux, rt_sigframe is used for all 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. |
| |
| /* Many of these byzantine details derived from |
| linux-2.6.13/arch/ppc64/kernel/signal.c */ |
| |
| #define TRAMP_SIZE 6 /* who knows why - it only needs to be 2. */ |
| |
| /* Structure containing bits of information that we want to save |
| on signal delivery. */ |
| struct vg_sig_private { |
| UInt magicPI; |
| UInt sigNo_private; |
| ULong _unused; /* makes the struct size be zero % 16 */ |
| VexGuestPPC64State vex_shadow1; |
| VexGuestPPC64State vex_shadow2; |
| }; |
| |
| /* Structure put on stack for all signal handlers. */ |
| struct rt_sigframe { |
| struct vki_ucontext uc; |
| ULong _unused[2]; |
| UInt tramp[TRAMP_SIZE]; |
| struct vki_siginfo* pinfo; |
| void* puc; |
| vki_siginfo_t info; |
| struct vg_sig_private priv; |
| UChar abigap[288]; // unused |
| }; |
| |
| #define SET_SIGNAL_LR(zztst, zzval) \ |
| do { tst->arch.vex.guest_LR = (zzval); \ |
| VG_TRACK( post_reg_write, Vg_CoreSignal, tst->tid, \ |
| offsetof(VexGuestPPC64State,guest_LR), \ |
| sizeof(UWord) ); \ |
| } while (0) |
| |
| #define SET_SIGNAL_GPR(zztst, zzn, zzval) \ |
| do { tst->arch.vex.guest_GPR##zzn = (zzval); \ |
| VG_TRACK( post_reg_write, Vg_CoreSignal, tst->tid, \ |
| offsetof(VexGuestPPC64State,guest_GPR##zzn), \ |
| sizeof(UWord) ); \ |
| } while (0) |
| |
| |
| /* 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 const* stackseg = NULL; |
| |
| if (VG_(extend_stack)(tid, addr)) { |
| stackseg = VG_(am_find_nsegment)(addr); |
| if (0 && stackseg) |
| VG_(printf)("frame=%#lx seg=%#lx-%#lx\n", |
| addr, stackseg->start, stackseg->end); |
| } |
| |
| if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) { |
| VG_(message)( |
| Vg_UserMsg, |
| "Can't extend stack to %#lx during signal delivery for thread %d:\n", |
| addr, tid); |
| if (stackseg == NULL) |
| VG_(message)(Vg_UserMsg, " no stack segment\n"); |
| else |
| VG_(message)(Vg_UserMsg, " too small or bad protection modes\n"); |
| |
| /* 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, tid ); |
| |
| return True; |
| } |
| |
| |
| /* EXPORTED */ |
| void VG_(sigframe_create)( ThreadId tid, |
| 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 ) |
| { |
| struct vg_sig_private* priv; |
| Addr sp; |
| ThreadState* tst; |
| Int sigNo = siginfo->si_signo; |
| /* Addr faultaddr; */ /* UNUSED */ |
| struct rt_sigframe* frame; |
| |
| /* Stack must be 16-byte aligned */ |
| vg_assert(VG_IS_16_ALIGNED(sizeof(struct vg_sig_private))); |
| vg_assert(VG_IS_16_ALIGNED(sizeof(struct rt_sigframe))); |
| |
| sp_top_of_frame &= ~0xf; |
| sp = sp_top_of_frame - sizeof(struct rt_sigframe); |
| |
| tst = VG_(get_ThreadState)(tid); |
| if (!extend(tst, sp, sp_top_of_frame - sp)) |
| return; |
| |
| vg_assert(VG_IS_16_ALIGNED(sp)); |
| |
| frame = (struct rt_sigframe *) sp; |
| |
| /* clear it (conservatively) */ |
| VG_(memset)(frame, 0, sizeof(*frame)); |
| |
| ///////// |
| frame->pinfo = &frame->info; |
| frame->puc = &frame->uc; |
| |
| frame->uc.uc_flags = 0; |
| frame->uc.uc_link = 0; |
| ///////// |
| |
| /* Set up the stack chain pointer */ |
| VG_TRACK( pre_mem_write, Vg_CoreSignal, tid, "signal handler frame", |
| sp, sizeof(UWord) ); |
| *(Addr *)sp = tst->arch.vex.guest_GPR1; |
| VG_TRACK( post_mem_write, Vg_CoreSignal, tid, |
| sp, sizeof(UWord) ); |
| |
| /* UNUSED: |
| faultaddr = (Addr)siginfo->_sifields._sigfault._addr; |
| if (sigNo == VKI_SIGILL && siginfo->si_code > 0) |
| faultaddr = tst->arch.vex.guest_CIA; |
| */ |
| |
| VG_(memcpy)(&frame->info, siginfo, sizeof(*siginfo)); |
| VG_TRACK( post_mem_write, Vg_CoreSignal, tid, |
| (Addr)&frame->info, sizeof(frame->info) ); |
| |
| frame->uc.uc_flags = 0; |
| frame->uc.uc_link = 0; |
| frame->uc.uc_stack = tst->altstack; |
| frame->uc.uc_sigmask = tst->sig_mask; |
| VG_TRACK( post_mem_write, Vg_CoreSignal, tid, |
| (Addr)(&frame->uc), sizeof(frame->uc) ); |
| |
| # define DO(gpr) frame->uc.uc_mcontext.gp_regs[VKI_PT_R0+gpr] \ |
| = tst->arch.vex.guest_GPR##gpr |
| DO(0); DO(1); DO(2); DO(3); DO(4); DO(5); DO(6); DO(7); |
| DO(8); DO(9); DO(10); DO(11); DO(12); DO(13); DO(14); DO(15); |
| DO(16); DO(17); DO(18); DO(19); DO(20); DO(21); DO(22); DO(23); |
| DO(24); DO(25); DO(26); DO(27); DO(28); DO(29); DO(30); DO(31); |
| # undef DO |
| |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_NIP] = tst->arch.vex.guest_CIA; |
| #ifdef VGP_ppc64le_linux |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_MSR] = 0xf033; /* pretty arbitrary */ |
| #else |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_MSR] = 0xf032; /* pretty arbitrary */ |
| #endif |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_ORIG_R3] = tst->arch.vex.guest_GPR3; |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_CTR] = tst->arch.vex.guest_CTR; |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_LNK] = tst->arch.vex.guest_LR; |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_XER] = LibVEX_GuestPPC64_get_XER( |
| &tst->arch.vex); |
| frame->uc.uc_mcontext.gp_regs[VKI_PT_CCR] = LibVEX_GuestPPC64_get_CR( |
| &tst->arch.vex); |
| //mc->mc_gregs[VKI_PT_MQ] = 0; |
| //mc->mc_gregs[VKI_PT_TRAP] = 0; |
| //mc->mc_gregs[VKI_PT_DAR] = fault_addr; |
| //mc->mc_gregs[VKI_PT_DSISR] = 0; |
| //mc->mc_gregs[VKI_PT_RESULT] = 0; |
| |
| /* XXX should do FP and vector regs */ |
| |
| /* set up signal return trampoline */ |
| /* NB. 5 Sept 07. mc->mc_pad[0..1] used to contain a the code to |
| which the signal handler returns, and it just did sys_sigreturn |
| or sys_rt_sigreturn. But this doesn't work if the stack is |
| non-executable, and it isn't consistent with the x86-linux and |
| amd64-linux scheme for removing the stack frame. So instead be |
| consistent and use a stub in m_trampoline. Then it doesn't |
| matter whether or not the (guest) stack is executable. This |
| fixes #149519 and #145837. */ |
| frame->tramp[0] = 0; /* invalid */ |
| frame->tramp[1] = 0; /* invalid */ |
| VG_TRACK(post_mem_write, Vg_CoreSignal, tst->tid, |
| (Addr)&frame->tramp, sizeof(frame->tramp)); |
| |
| /* invalidate any translation of this area */ |
| VG_(discard_translations)( (Addr)&frame->tramp[0], |
| sizeof(frame->tramp), "stack_mcontext" ); |
| |
| /* set the signal handler to return to the trampoline */ |
| SET_SIGNAL_LR(tst, (Addr)&VG_(ppc64_linux_SUBST_FOR_rt_sigreturn)); |
| |
| /* Stack pointer for the handler .. (note, back chain set |
| earlier) */ |
| SET_SIGNAL_GPR(tid, 1, sp); |
| |
| /* Args for the handler .. */ |
| SET_SIGNAL_GPR(tid, 3, sigNo); |
| SET_SIGNAL_GPR(tid, 4, (Addr) &frame->info); |
| SET_SIGNAL_GPR(tid, 5, (Addr) &frame->uc); |
| /* the kernel sets this, though it doesn't seem to be in the ABI */ |
| SET_SIGNAL_GPR(tid, 6, (Addr) &frame->info); |
| |
| /* Handler is in fact a standard ppc64-linux function descriptor, |
| so extract the function entry point and also the toc ptr to use. */ |
| #if defined(VGP_ppc64be_linux) |
| SET_SIGNAL_GPR(tid, 2, (Addr) ((ULong*)handler)[1]); |
| tst->arch.vex.guest_CIA = (Addr) ((ULong*)handler)[0]; |
| #else |
| SET_SIGNAL_GPR(tid, 12, (Addr) handler); |
| tst->arch.vex.guest_CIA = (Addr) handler; |
| #endif |
| priv = &frame->priv; |
| priv->magicPI = 0x31415927; |
| priv->sigNo_private = sigNo; |
| priv->vex_shadow1 = tst->arch.vex_shadow1; |
| priv->vex_shadow2 = tst->arch.vex_shadow2; |
| |
| if (0) |
| VG_(printf)("pushed signal frame; %%R1 now = %#lx, " |
| "next %%CIA = %#llx, status=%d\n", |
| sp, tst->arch.vex.guest_CIA, tst->status); |
| } |
| |
| |
| /*------------------------------------------------------------*/ |
| /*--- Destroying signal frames ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /* EXPORTED */ |
| void VG_(sigframe_destroy)( ThreadId tid, Bool isRT ) |
| { |
| ThreadState *tst; |
| struct vg_sig_private *priv; |
| Addr sp; |
| UInt frame_size; |
| struct rt_sigframe *frame; |
| Int sigNo; |
| Bool has_siginfo = isRT; |
| |
| vg_assert(VG_(is_valid_tid)(tid)); |
| tst = VG_(get_ThreadState)(tid); |
| |
| /* Check that the stack frame looks valid */ |
| sp = tst->arch.vex.guest_GPR1; |
| vg_assert(VG_IS_16_ALIGNED(sp)); |
| /* JRS 17 Nov 05: This code used to check that *sp -- which should |
| have been set by the stwu at the start of the handler -- points |
| to just above the frame (ie, the previous frame). However, that |
| isn't valid when delivering signals on alt stacks. So I removed |
| it. The frame is still sanity-checked using the priv->magicPI |
| field. */ |
| |
| frame = (struct rt_sigframe *)sp; |
| frame_size = sizeof(*frame); |
| priv = &frame->priv; |
| vg_assert(priv->magicPI == 0x31415927); |
| tst->sig_mask = frame->uc.uc_sigmask; |
| tst->tmp_sig_mask = tst->sig_mask; |
| |
| sigNo = priv->sigNo_private; |
| |
| # define DO(gpr) tst->arch.vex.guest_GPR##gpr \ |
| = frame->uc.uc_mcontext.gp_regs[VKI_PT_R0+gpr] |
| DO(0); DO(1); DO(2); DO(3); DO(4); DO(5); DO(6); DO(7); |
| DO(8); DO(9); DO(10); DO(11); DO(12); DO(13); DO(14); DO(15); |
| DO(16); DO(17); DO(18); DO(19); DO(20); DO(21); DO(22); DO(23); |
| DO(24); DO(25); DO(26); DO(27); DO(28); DO(29); DO(30); DO(31); |
| # undef DO |
| |
| tst->arch.vex.guest_CIA = frame->uc.uc_mcontext.gp_regs[VKI_PT_NIP]; |
| |
| LibVEX_GuestPPC64_put_CR( frame->uc.uc_mcontext.gp_regs[VKI_PT_CCR], |
| &tst->arch.vex ); |
| |
| tst->arch.vex.guest_LR = frame->uc.uc_mcontext.gp_regs[VKI_PT_LNK]; |
| tst->arch.vex.guest_CTR = frame->uc.uc_mcontext.gp_regs[VKI_PT_CTR]; |
| LibVEX_GuestPPC64_put_XER( frame->uc.uc_mcontext.gp_regs[VKI_PT_XER], |
| &tst->arch.vex ); |
| |
| tst->arch.vex_shadow1 = priv->vex_shadow1; |
| tst->arch.vex_shadow2 = priv->vex_shadow2; |
| |
| VG_TRACK(die_mem_stack_signal, sp, frame_size); |
| |
| if (VG_(clo_trace_signals)) |
| VG_(message)(Vg_DebugMsg, |
| "vg_pop_signal_frame (thread %d): isRT=%d " |
| "valid magic; EIP=%#llx\n", |
| tid, has_siginfo, tst->arch.vex.guest_CIA); |
| |
| /* tell the tools */ |
| VG_TRACK( post_deliver_signal, tid, sigNo ); |
| } |
| |
| #endif // defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux) |
| |
| /*--------------------------------------------------------------------*/ |
| /*--- end ---*/ |
| /*--------------------------------------------------------------------*/ |
