git: 12ca33f44fc7 - main - amd64: move signal handling and register structures manipulations into exec_machdep.c
Konstantin Belousov
kib at FreeBSD.org
Tue Sep 21 17:21:13 UTC 2021
The branch main has been updated by kib:
URL: https://cgit.FreeBSD.org/src/commit/?id=12ca33f44fc76890336f517ace402b47b9afb134
commit 12ca33f44fc76890336f517ace402b47b9afb134
Author: Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-09-13 20:33:37 +0000
Commit: Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-09-21 17:20:15 +0000
amd64: move signal handling and register structures manipulations into exec_machdep.c
from machdep.c which is too large pile of unrelated things.
Some ptrace functions are moved from machdep.c to ptrace_machdep.c.
Now machdep.c contains code mostly related to the low level initialization
and regular low level operation of the architecture, while signal MD code
and registers handling is placed in exec_machdep.c.
Reviewed by: jhb, markj
Discussed with: jrtc27
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31954
---
sys/amd64/amd64/exec_machdep.c | 987 +++++++++++++++++++++++++++++++++++++++
sys/amd64/amd64/machdep.c | 924 ------------------------------------
sys/amd64/amd64/ptrace_machdep.c | 33 ++
sys/conf/files.amd64 | 1 +
4 files changed, 1021 insertions(+), 924 deletions(-)
diff --git a/sys/amd64/amd64/exec_machdep.c b/sys/amd64/amd64/exec_machdep.c
new file mode 100644
index 000000000000..5cd905e1051b
--- /dev/null
+++ b/sys/amd64/amd64/exec_machdep.c
@@ -0,0 +1,987 @@
+/*-
+ * SPDX-License-Identifier: BSD-4-Clause
+ *
+ * Copyright (c) 2003 Peter Wemm.
+ * Copyright (c) 1992 Terrence R. Lambert.
+ * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * William Jolitz.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * from: @(#)machdep.c 7.4 (Berkeley) 6/3/91
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_cpu.h"
+#include "opt_ddb.h"
+#include "opt_kstack_pages.h"
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/systm.h>
+#include <sys/exec.h>
+#include <sys/imgact.h>
+#include <sys/kdb.h>
+#include <sys/kernel.h>
+#include <sys/ktr.h>
+#include <sys/linker.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mutex.h>
+#include <sys/pcpu.h>
+#include <sys/reg.h>
+#include <sys/rwlock.h>
+#include <sys/signalvar.h>
+#ifdef SMP
+#include <sys/smp.h>
+#endif
+#include <sys/syscallsubr.h>
+#include <sys/sysctl.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+#include <sys/ucontext.h>
+#include <sys/vmmeter.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/vm_extern.h>
+#include <vm/pmap.h>
+
+#ifdef DDB
+#ifndef KDB
+#error KDB must be enabled in order for DDB to work!
+#endif
+#include <ddb/ddb.h>
+#include <ddb/db_sym.h>
+#endif
+
+#include <machine/vmparam.h>
+#include <machine/frame.h>
+#include <machine/md_var.h>
+#include <machine/pcb.h>
+#include <machine/proc.h>
+#include <machine/sigframe.h>
+#include <machine/specialreg.h>
+#include <machine/trap.h>
+
+static void get_fpcontext(struct thread *td, mcontext_t *mcp,
+ char *xfpusave, size_t xfpusave_len);
+static int set_fpcontext(struct thread *td, mcontext_t *mcp,
+ char *xfpustate, size_t xfpustate_len);
+
+/*
+ * Send an interrupt to process.
+ *
+ * Stack is set up to allow sigcode stored at top to call routine,
+ * followed by call to sigreturn routine below. After sigreturn
+ * resets the signal mask, the stack, and the frame pointer, it
+ * returns to the user specified pc, psl.
+ */
+void
+sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
+{
+ struct sigframe sf, *sfp;
+ struct pcb *pcb;
+ struct proc *p;
+ struct thread *td;
+ struct sigacts *psp;
+ char *sp;
+ struct trapframe *regs;
+ char *xfpusave;
+ size_t xfpusave_len;
+ int sig;
+ int oonstack;
+
+ td = curthread;
+ pcb = td->td_pcb;
+ p = td->td_proc;
+ PROC_LOCK_ASSERT(p, MA_OWNED);
+ sig = ksi->ksi_signo;
+ psp = p->p_sigacts;
+ mtx_assert(&psp->ps_mtx, MA_OWNED);
+ regs = td->td_frame;
+ oonstack = sigonstack(regs->tf_rsp);
+
+ if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) {
+ xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu);
+ xfpusave = __builtin_alloca(xfpusave_len);
+ } else {
+ xfpusave_len = 0;
+ xfpusave = NULL;
+ }
+
+ /* Save user context. */
+ bzero(&sf, sizeof(sf));
+ sf.sf_uc.uc_sigmask = *mask;
+ sf.sf_uc.uc_stack = td->td_sigstk;
+ sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
+ ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
+ sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
+ bcopy(regs, &sf.sf_uc.uc_mcontext.mc_rdi, sizeof(*regs));
+ sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
+ get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
+ fpstate_drop(td);
+ update_pcb_bases(pcb);
+ sf.sf_uc.uc_mcontext.mc_fsbase = pcb->pcb_fsbase;
+ sf.sf_uc.uc_mcontext.mc_gsbase = pcb->pcb_gsbase;
+ bzero(sf.sf_uc.uc_mcontext.mc_spare,
+ sizeof(sf.sf_uc.uc_mcontext.mc_spare));
+
+ /* Allocate space for the signal handler context. */
+ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
+ SIGISMEMBER(psp->ps_sigonstack, sig)) {
+ sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
+#if defined(COMPAT_43)
+ td->td_sigstk.ss_flags |= SS_ONSTACK;
+#endif
+ } else
+ sp = (char *)regs->tf_rsp - 128;
+ if (xfpusave != NULL) {
+ sp -= xfpusave_len;
+ sp = (char *)((unsigned long)sp & ~0x3Ful);
+ sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
+ }
+ sp -= sizeof(struct sigframe);
+ /* Align to 16 bytes. */
+ sfp = (struct sigframe *)((unsigned long)sp & ~0xFul);
+
+ /* Build the argument list for the signal handler. */
+ regs->tf_rdi = sig; /* arg 1 in %rdi */
+ regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */
+ bzero(&sf.sf_si, sizeof(sf.sf_si));
+ if (SIGISMEMBER(psp->ps_siginfo, sig)) {
+ /* Signal handler installed with SA_SIGINFO. */
+ regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */
+ sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher;
+
+ /* Fill in POSIX parts */
+ sf.sf_si = ksi->ksi_info;
+ sf.sf_si.si_signo = sig; /* maybe a translated signal */
+ regs->tf_rcx = (register_t)ksi->ksi_addr; /* arg 4 in %rcx */
+ } else {
+ /* Old FreeBSD-style arguments. */
+ regs->tf_rsi = ksi->ksi_code; /* arg 2 in %rsi */
+ regs->tf_rcx = (register_t)ksi->ksi_addr; /* arg 4 in %rcx */
+ sf.sf_ahu.sf_handler = catcher;
+ }
+ mtx_unlock(&psp->ps_mtx);
+ PROC_UNLOCK(p);
+
+ /*
+ * Copy the sigframe out to the user's stack.
+ */
+ if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
+ (xfpusave != NULL && copyout(xfpusave,
+ (void *)sf.sf_uc.uc_mcontext.mc_xfpustate, xfpusave_len)
+ != 0)) {
+#ifdef DEBUG
+ printf("process %ld has trashed its stack\n", (long)p->p_pid);
+#endif
+ PROC_LOCK(p);
+ sigexit(td, SIGILL);
+ }
+
+ regs->tf_rsp = (long)sfp;
+ regs->tf_rip = p->p_sysent->sv_sigcode_base;
+ regs->tf_rflags &= ~(PSL_T | PSL_D);
+ regs->tf_cs = _ucodesel;
+ regs->tf_ds = _udatasel;
+ regs->tf_ss = _udatasel;
+ regs->tf_es = _udatasel;
+ regs->tf_fs = _ufssel;
+ regs->tf_gs = _ugssel;
+ regs->tf_flags = TF_HASSEGS;
+ PROC_LOCK(p);
+ mtx_lock(&psp->ps_mtx);
+}
+
+/*
+ * System call to cleanup state after a signal
+ * has been taken. Reset signal mask and
+ * stack state from context left by sendsig (above).
+ * Return to previous pc and psl as specified by
+ * context left by sendsig. Check carefully to
+ * make sure that the user has not modified the
+ * state to gain improper privileges.
+ */
+int
+sys_sigreturn(td, uap)
+ struct thread *td;
+ struct sigreturn_args /* {
+ const struct __ucontext *sigcntxp;
+ } */ *uap;
+{
+ ucontext_t uc;
+ struct pcb *pcb;
+ struct proc *p;
+ struct trapframe *regs;
+ ucontext_t *ucp;
+ char *xfpustate;
+ size_t xfpustate_len;
+ long rflags;
+ int cs, error, ret;
+ ksiginfo_t ksi;
+
+ pcb = td->td_pcb;
+ p = td->td_proc;
+
+ error = copyin(uap->sigcntxp, &uc, sizeof(uc));
+ if (error != 0) {
+ uprintf("pid %d (%s): sigreturn copyin failed\n",
+ p->p_pid, td->td_name);
+ return (error);
+ }
+ ucp = &uc;
+ if ((ucp->uc_mcontext.mc_flags & ~_MC_FLAG_MASK) != 0) {
+ uprintf("pid %d (%s): sigreturn mc_flags %x\n", p->p_pid,
+ td->td_name, ucp->uc_mcontext.mc_flags);
+ return (EINVAL);
+ }
+ regs = td->td_frame;
+ rflags = ucp->uc_mcontext.mc_rflags;
+ /*
+ * Don't allow users to change privileged or reserved flags.
+ */
+ if (!EFL_SECURE(rflags, regs->tf_rflags)) {
+ uprintf("pid %d (%s): sigreturn rflags = 0x%lx\n", p->p_pid,
+ td->td_name, rflags);
+ return (EINVAL);
+ }
+
+ /*
+ * Don't allow users to load a valid privileged %cs. Let the
+ * hardware check for invalid selectors, excess privilege in
+ * other selectors, invalid %eip's and invalid %esp's.
+ */
+ cs = ucp->uc_mcontext.mc_cs;
+ if (!CS_SECURE(cs)) {
+ uprintf("pid %d (%s): sigreturn cs = 0x%x\n", p->p_pid,
+ td->td_name, cs);
+ ksiginfo_init_trap(&ksi);
+ ksi.ksi_signo = SIGBUS;
+ ksi.ksi_code = BUS_OBJERR;
+ ksi.ksi_trapno = T_PROTFLT;
+ ksi.ksi_addr = (void *)regs->tf_rip;
+ trapsignal(td, &ksi);
+ return (EINVAL);
+ }
+
+ if ((uc.uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
+ xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
+ if (xfpustate_len > cpu_max_ext_state_size -
+ sizeof(struct savefpu)) {
+ uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
+ p->p_pid, td->td_name, xfpustate_len);
+ return (EINVAL);
+ }
+ xfpustate = __builtin_alloca(xfpustate_len);
+ error = copyin((const void *)uc.uc_mcontext.mc_xfpustate,
+ xfpustate, xfpustate_len);
+ if (error != 0) {
+ uprintf(
+ "pid %d (%s): sigreturn copying xfpustate failed\n",
+ p->p_pid, td->td_name);
+ return (error);
+ }
+ } else {
+ xfpustate = NULL;
+ xfpustate_len = 0;
+ }
+ ret = set_fpcontext(td, &ucp->uc_mcontext, xfpustate, xfpustate_len);
+ if (ret != 0) {
+ uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
+ p->p_pid, td->td_name, ret);
+ return (ret);
+ }
+ bcopy(&ucp->uc_mcontext.mc_rdi, regs, sizeof(*regs));
+ update_pcb_bases(pcb);
+ pcb->pcb_fsbase = ucp->uc_mcontext.mc_fsbase;
+ pcb->pcb_gsbase = ucp->uc_mcontext.mc_gsbase;
+
+#if defined(COMPAT_43)
+ if (ucp->uc_mcontext.mc_onstack & 1)
+ td->td_sigstk.ss_flags |= SS_ONSTACK;
+ else
+ td->td_sigstk.ss_flags &= ~SS_ONSTACK;
+#endif
+
+ kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
+ return (EJUSTRETURN);
+}
+
+#ifdef COMPAT_FREEBSD4
+int
+freebsd4_sigreturn(struct thread *td, struct freebsd4_sigreturn_args *uap)
+{
+
+ return sys_sigreturn(td, (struct sigreturn_args *)uap);
+}
+#endif
+
+/*
+ * Reset the hardware debug registers if they were in use.
+ * They won't have any meaning for the newly exec'd process.
+ */
+void
+x86_clear_dbregs(struct pcb *pcb)
+{
+ if ((pcb->pcb_flags & PCB_DBREGS) == 0)
+ return;
+
+ pcb->pcb_dr0 = 0;
+ pcb->pcb_dr1 = 0;
+ pcb->pcb_dr2 = 0;
+ pcb->pcb_dr3 = 0;
+ pcb->pcb_dr6 = 0;
+ pcb->pcb_dr7 = 0;
+
+ if (pcb == curpcb) {
+ /*
+ * Clear the debug registers on the running CPU,
+ * otherwise they will end up affecting the next
+ * process we switch to.
+ */
+ reset_dbregs();
+ }
+ clear_pcb_flags(pcb, PCB_DBREGS);
+}
+
+/*
+ * Reset registers to default values on exec.
+ */
+void
+exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
+{
+ struct trapframe *regs;
+ struct pcb *pcb;
+ register_t saved_rflags;
+
+ regs = td->td_frame;
+ pcb = td->td_pcb;
+
+ if (td->td_proc->p_md.md_ldt != NULL)
+ user_ldt_free(td);
+
+ update_pcb_bases(pcb);
+ pcb->pcb_fsbase = 0;
+ pcb->pcb_gsbase = 0;
+ clear_pcb_flags(pcb, PCB_32BIT);
+ pcb->pcb_initial_fpucw = __INITIAL_FPUCW__;
+
+ saved_rflags = regs->tf_rflags & PSL_T;
+ bzero((char *)regs, sizeof(struct trapframe));
+ regs->tf_rip = imgp->entry_addr;
+ regs->tf_rsp = ((stack - 8) & ~0xFul) + 8;
+ regs->tf_rdi = stack; /* argv */
+ regs->tf_rflags = PSL_USER | saved_rflags;
+ regs->tf_ss = _udatasel;
+ regs->tf_cs = _ucodesel;
+ regs->tf_ds = _udatasel;
+ regs->tf_es = _udatasel;
+ regs->tf_fs = _ufssel;
+ regs->tf_gs = _ugssel;
+ regs->tf_flags = TF_HASSEGS;
+
+ x86_clear_dbregs(pcb);
+
+ /*
+ * Drop the FP state if we hold it, so that the process gets a
+ * clean FP state if it uses the FPU again.
+ */
+ fpstate_drop(td);
+}
+
+int
+fill_regs(struct thread *td, struct reg *regs)
+{
+ struct trapframe *tp;
+
+ tp = td->td_frame;
+ return (fill_frame_regs(tp, regs));
+}
+
+int
+fill_frame_regs(struct trapframe *tp, struct reg *regs)
+{
+
+ regs->r_r15 = tp->tf_r15;
+ regs->r_r14 = tp->tf_r14;
+ regs->r_r13 = tp->tf_r13;
+ regs->r_r12 = tp->tf_r12;
+ regs->r_r11 = tp->tf_r11;
+ regs->r_r10 = tp->tf_r10;
+ regs->r_r9 = tp->tf_r9;
+ regs->r_r8 = tp->tf_r8;
+ regs->r_rdi = tp->tf_rdi;
+ regs->r_rsi = tp->tf_rsi;
+ regs->r_rbp = tp->tf_rbp;
+ regs->r_rbx = tp->tf_rbx;
+ regs->r_rdx = tp->tf_rdx;
+ regs->r_rcx = tp->tf_rcx;
+ regs->r_rax = tp->tf_rax;
+ regs->r_rip = tp->tf_rip;
+ regs->r_cs = tp->tf_cs;
+ regs->r_rflags = tp->tf_rflags;
+ regs->r_rsp = tp->tf_rsp;
+ regs->r_ss = tp->tf_ss;
+ if (tp->tf_flags & TF_HASSEGS) {
+ regs->r_ds = tp->tf_ds;
+ regs->r_es = tp->tf_es;
+ regs->r_fs = tp->tf_fs;
+ regs->r_gs = tp->tf_gs;
+ } else {
+ regs->r_ds = 0;
+ regs->r_es = 0;
+ regs->r_fs = 0;
+ regs->r_gs = 0;
+ }
+ regs->r_err = 0;
+ regs->r_trapno = 0;
+ return (0);
+}
+
+int
+set_regs(struct thread *td, struct reg *regs)
+{
+ struct trapframe *tp;
+ register_t rflags;
+
+ tp = td->td_frame;
+ rflags = regs->r_rflags & 0xffffffff;
+ if (!EFL_SECURE(rflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
+ return (EINVAL);
+ tp->tf_r15 = regs->r_r15;
+ tp->tf_r14 = regs->r_r14;
+ tp->tf_r13 = regs->r_r13;
+ tp->tf_r12 = regs->r_r12;
+ tp->tf_r11 = regs->r_r11;
+ tp->tf_r10 = regs->r_r10;
+ tp->tf_r9 = regs->r_r9;
+ tp->tf_r8 = regs->r_r8;
+ tp->tf_rdi = regs->r_rdi;
+ tp->tf_rsi = regs->r_rsi;
+ tp->tf_rbp = regs->r_rbp;
+ tp->tf_rbx = regs->r_rbx;
+ tp->tf_rdx = regs->r_rdx;
+ tp->tf_rcx = regs->r_rcx;
+ tp->tf_rax = regs->r_rax;
+ tp->tf_rip = regs->r_rip;
+ tp->tf_cs = regs->r_cs;
+ tp->tf_rflags = rflags;
+ tp->tf_rsp = regs->r_rsp;
+ tp->tf_ss = regs->r_ss;
+ if (0) { /* XXXKIB */
+ tp->tf_ds = regs->r_ds;
+ tp->tf_es = regs->r_es;
+ tp->tf_fs = regs->r_fs;
+ tp->tf_gs = regs->r_gs;
+ tp->tf_flags = TF_HASSEGS;
+ }
+ set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
+ return (0);
+}
+
+/* XXX check all this stuff! */
+/* externalize from sv_xmm */
+static void
+fill_fpregs_xmm(struct savefpu *sv_xmm, struct fpreg *fpregs)
+{
+ struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
+ struct envxmm *penv_xmm = &sv_xmm->sv_env;
+ int i;
+
+ /* pcb -> fpregs */
+ bzero(fpregs, sizeof(*fpregs));
+
+ /* FPU control/status */
+ penv_fpreg->en_cw = penv_xmm->en_cw;
+ penv_fpreg->en_sw = penv_xmm->en_sw;
+ penv_fpreg->en_tw = penv_xmm->en_tw;
+ penv_fpreg->en_opcode = penv_xmm->en_opcode;
+ penv_fpreg->en_rip = penv_xmm->en_rip;
+ penv_fpreg->en_rdp = penv_xmm->en_rdp;
+ penv_fpreg->en_mxcsr = penv_xmm->en_mxcsr;
+ penv_fpreg->en_mxcsr_mask = penv_xmm->en_mxcsr_mask;
+
+ /* FPU registers */
+ for (i = 0; i < 8; ++i)
+ bcopy(sv_xmm->sv_fp[i].fp_acc.fp_bytes, fpregs->fpr_acc[i], 10);
+
+ /* SSE registers */
+ for (i = 0; i < 16; ++i)
+ bcopy(sv_xmm->sv_xmm[i].xmm_bytes, fpregs->fpr_xacc[i], 16);
+}
+
+/* internalize from fpregs into sv_xmm */
+static void
+set_fpregs_xmm(struct fpreg *fpregs, struct savefpu *sv_xmm)
+{
+ struct envxmm *penv_xmm = &sv_xmm->sv_env;
+ struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
+ int i;
+
+ /* fpregs -> pcb */
+ /* FPU control/status */
+ penv_xmm->en_cw = penv_fpreg->en_cw;
+ penv_xmm->en_sw = penv_fpreg->en_sw;
+ penv_xmm->en_tw = penv_fpreg->en_tw;
+ penv_xmm->en_opcode = penv_fpreg->en_opcode;
+ penv_xmm->en_rip = penv_fpreg->en_rip;
+ penv_xmm->en_rdp = penv_fpreg->en_rdp;
+ penv_xmm->en_mxcsr = penv_fpreg->en_mxcsr;
+ penv_xmm->en_mxcsr_mask = penv_fpreg->en_mxcsr_mask & cpu_mxcsr_mask;
+
+ /* FPU registers */
+ for (i = 0; i < 8; ++i)
+ bcopy(fpregs->fpr_acc[i], sv_xmm->sv_fp[i].fp_acc.fp_bytes, 10);
+
+ /* SSE registers */
+ for (i = 0; i < 16; ++i)
+ bcopy(fpregs->fpr_xacc[i], sv_xmm->sv_xmm[i].xmm_bytes, 16);
+}
+
+/* externalize from td->pcb */
+int
+fill_fpregs(struct thread *td, struct fpreg *fpregs)
+{
+
+ KASSERT(td == curthread || TD_IS_SUSPENDED(td) ||
+ P_SHOULDSTOP(td->td_proc),
+ ("not suspended thread %p", td));
+ fpugetregs(td);
+ fill_fpregs_xmm(get_pcb_user_save_td(td), fpregs);
+ return (0);
+}
+
+/* internalize to td->pcb */
+int
+set_fpregs(struct thread *td, struct fpreg *fpregs)
+{
+
+ critical_enter();
+ set_fpregs_xmm(fpregs, get_pcb_user_save_td(td));
+ fpuuserinited(td);
+ critical_exit();
+ return (0);
+}
+
+/*
+ * Get machine context.
+ */
+int
+get_mcontext(struct thread *td, mcontext_t *mcp, int flags)
+{
+ struct pcb *pcb;
+ struct trapframe *tp;
+
+ pcb = td->td_pcb;
+ tp = td->td_frame;
+ PROC_LOCK(curthread->td_proc);
+ mcp->mc_onstack = sigonstack(tp->tf_rsp);
+ PROC_UNLOCK(curthread->td_proc);
+ mcp->mc_r15 = tp->tf_r15;
+ mcp->mc_r14 = tp->tf_r14;
+ mcp->mc_r13 = tp->tf_r13;
+ mcp->mc_r12 = tp->tf_r12;
+ mcp->mc_r11 = tp->tf_r11;
+ mcp->mc_r10 = tp->tf_r10;
+ mcp->mc_r9 = tp->tf_r9;
+ mcp->mc_r8 = tp->tf_r8;
+ mcp->mc_rdi = tp->tf_rdi;
+ mcp->mc_rsi = tp->tf_rsi;
+ mcp->mc_rbp = tp->tf_rbp;
+ mcp->mc_rbx = tp->tf_rbx;
+ mcp->mc_rcx = tp->tf_rcx;
+ mcp->mc_rflags = tp->tf_rflags;
+ if (flags & GET_MC_CLEAR_RET) {
+ mcp->mc_rax = 0;
+ mcp->mc_rdx = 0;
+ mcp->mc_rflags &= ~PSL_C;
+ } else {
+ mcp->mc_rax = tp->tf_rax;
+ mcp->mc_rdx = tp->tf_rdx;
+ }
+ mcp->mc_rip = tp->tf_rip;
+ mcp->mc_cs = tp->tf_cs;
+ mcp->mc_rsp = tp->tf_rsp;
+ mcp->mc_ss = tp->tf_ss;
+ mcp->mc_ds = tp->tf_ds;
+ mcp->mc_es = tp->tf_es;
+ mcp->mc_fs = tp->tf_fs;
+ mcp->mc_gs = tp->tf_gs;
+ mcp->mc_flags = tp->tf_flags;
+ mcp->mc_len = sizeof(*mcp);
+ get_fpcontext(td, mcp, NULL, 0);
+ update_pcb_bases(pcb);
+ mcp->mc_fsbase = pcb->pcb_fsbase;
+ mcp->mc_gsbase = pcb->pcb_gsbase;
+ mcp->mc_xfpustate = 0;
+ mcp->mc_xfpustate_len = 0;
+ bzero(mcp->mc_spare, sizeof(mcp->mc_spare));
+ return (0);
+}
+
+/*
+ * Set machine context.
+ *
+ * However, we don't set any but the user modifiable flags, and we won't
+ * touch the cs selector.
+ */
+int
+set_mcontext(struct thread *td, mcontext_t *mcp)
+{
+ struct pcb *pcb;
+ struct trapframe *tp;
+ char *xfpustate;
+ long rflags;
+ int ret;
+
+ pcb = td->td_pcb;
+ tp = td->td_frame;
+ if (mcp->mc_len != sizeof(*mcp) ||
+ (mcp->mc_flags & ~_MC_FLAG_MASK) != 0)
+ return (EINVAL);
+ rflags = (mcp->mc_rflags & PSL_USERCHANGE) |
+ (tp->tf_rflags & ~PSL_USERCHANGE);
+ if (mcp->mc_flags & _MC_HASFPXSTATE) {
+ if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
+ sizeof(struct savefpu))
+ return (EINVAL);
+ xfpustate = __builtin_alloca(mcp->mc_xfpustate_len);
+ ret = copyin((void *)mcp->mc_xfpustate, xfpustate,
+ mcp->mc_xfpustate_len);
+ if (ret != 0)
+ return (ret);
+ } else
+ xfpustate = NULL;
+ ret = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
+ if (ret != 0)
+ return (ret);
+ tp->tf_r15 = mcp->mc_r15;
+ tp->tf_r14 = mcp->mc_r14;
+ tp->tf_r13 = mcp->mc_r13;
+ tp->tf_r12 = mcp->mc_r12;
+ tp->tf_r11 = mcp->mc_r11;
+ tp->tf_r10 = mcp->mc_r10;
+ tp->tf_r9 = mcp->mc_r9;
+ tp->tf_r8 = mcp->mc_r8;
+ tp->tf_rdi = mcp->mc_rdi;
+ tp->tf_rsi = mcp->mc_rsi;
+ tp->tf_rbp = mcp->mc_rbp;
+ tp->tf_rbx = mcp->mc_rbx;
+ tp->tf_rdx = mcp->mc_rdx;
+ tp->tf_rcx = mcp->mc_rcx;
+ tp->tf_rax = mcp->mc_rax;
+ tp->tf_rip = mcp->mc_rip;
+ tp->tf_rflags = rflags;
+ tp->tf_rsp = mcp->mc_rsp;
+ tp->tf_ss = mcp->mc_ss;
+ tp->tf_flags = mcp->mc_flags;
+ if (tp->tf_flags & TF_HASSEGS) {
+ tp->tf_ds = mcp->mc_ds;
+ tp->tf_es = mcp->mc_es;
+ tp->tf_fs = mcp->mc_fs;
+ tp->tf_gs = mcp->mc_gs;
+ }
+ set_pcb_flags(pcb, PCB_FULL_IRET);
+ if (mcp->mc_flags & _MC_HASBASES) {
+ pcb->pcb_fsbase = mcp->mc_fsbase;
+ pcb->pcb_gsbase = mcp->mc_gsbase;
+ }
+ return (0);
+}
+
+static void
+get_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpusave,
+ size_t xfpusave_len)
+{
+ size_t max_len, len;
+
+ mcp->mc_ownedfp = fpugetregs(td);
+ bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0],
+ sizeof(mcp->mc_fpstate));
+ mcp->mc_fpformat = fpuformat();
+ if (!use_xsave || xfpusave_len == 0)
+ return;
+ max_len = cpu_max_ext_state_size - sizeof(struct savefpu);
+ len = xfpusave_len;
+ if (len > max_len) {
+ len = max_len;
+ bzero(xfpusave + max_len, len - max_len);
+ }
+ mcp->mc_flags |= _MC_HASFPXSTATE;
+ mcp->mc_xfpustate_len = len;
+ bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len);
+}
+
+static int
+set_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpustate,
+ size_t xfpustate_len)
+{
+ int error;
+
+ if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
+ return (0);
+ else if (mcp->mc_fpformat != _MC_FPFMT_XMM)
+ return (EINVAL);
+ else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) {
+ /* We don't care what state is left in the FPU or PCB. */
+ fpstate_drop(td);
+ error = 0;
+ } else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
+ mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
+ error = fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate,
+ xfpustate, xfpustate_len);
+ } else
+ return (EINVAL);
+ return (error);
+}
+
+void
+fpstate_drop(struct thread *td)
+{
+
+ KASSERT(PCB_USER_FPU(td->td_pcb), ("fpstate_drop: kernel-owned fpu"));
+ critical_enter();
+ if (PCPU_GET(fpcurthread) == td)
+ fpudrop();
+ /*
+ * XXX force a full drop of the fpu. The above only drops it if we
+ * owned it.
+ *
+ * XXX I don't much like fpugetuserregs()'s semantics of doing a full
+ * drop. Dropping only to the pcb matches fnsave's behaviour.
+ * We only need to drop to !PCB_INITDONE in sendsig(). But
+ * sendsig() is the only caller of fpugetuserregs()... perhaps we just
+ * have too many layers.
+ */
+ clear_pcb_flags(curthread->td_pcb,
+ PCB_FPUINITDONE | PCB_USERFPUINITDONE);
+ critical_exit();
+}
+
+int
+fill_dbregs(struct thread *td, struct dbreg *dbregs)
+{
+ struct pcb *pcb;
+
+ if (td == NULL) {
+ dbregs->dr[0] = rdr0();
+ dbregs->dr[1] = rdr1();
+ dbregs->dr[2] = rdr2();
+ dbregs->dr[3] = rdr3();
+ dbregs->dr[6] = rdr6();
+ dbregs->dr[7] = rdr7();
+ } else {
+ pcb = td->td_pcb;
+ dbregs->dr[0] = pcb->pcb_dr0;
+ dbregs->dr[1] = pcb->pcb_dr1;
+ dbregs->dr[2] = pcb->pcb_dr2;
+ dbregs->dr[3] = pcb->pcb_dr3;
+ dbregs->dr[6] = pcb->pcb_dr6;
+ dbregs->dr[7] = pcb->pcb_dr7;
+ }
+ dbregs->dr[4] = 0;
+ dbregs->dr[5] = 0;
+ dbregs->dr[8] = 0;
+ dbregs->dr[9] = 0;
+ dbregs->dr[10] = 0;
+ dbregs->dr[11] = 0;
+ dbregs->dr[12] = 0;
+ dbregs->dr[13] = 0;
+ dbregs->dr[14] = 0;
+ dbregs->dr[15] = 0;
+ return (0);
+}
+
+int
+set_dbregs(struct thread *td, struct dbreg *dbregs)
+{
+ struct pcb *pcb;
+ int i;
+
+ if (td == NULL) {
+ load_dr0(dbregs->dr[0]);
+ load_dr1(dbregs->dr[1]);
+ load_dr2(dbregs->dr[2]);
+ load_dr3(dbregs->dr[3]);
+ load_dr6(dbregs->dr[6]);
+ load_dr7(dbregs->dr[7]);
+ } else {
+ /*
+ * Don't let an illegal value for dr7 get set. Specifically,
+ * check for undefined settings. Setting these bit patterns
+ * result in undefined behaviour and can lead to an unexpected
+ * TRCTRAP or a general protection fault right here.
+ * Upper bits of dr6 and dr7 must not be set
+ */
+ for (i = 0; i < 4; i++) {
+ if (DBREG_DR7_ACCESS(dbregs->dr[7], i) == 0x02)
+ return (EINVAL);
+ if (td->td_frame->tf_cs == _ucode32sel &&
+ DBREG_DR7_LEN(dbregs->dr[7], i) == DBREG_DR7_LEN_8)
+ return (EINVAL);
+ }
+ if ((dbregs->dr[6] & 0xffffffff00000000ul) != 0 ||
+ (dbregs->dr[7] & 0xffffffff00000000ul) != 0)
+ return (EINVAL);
+
+ pcb = td->td_pcb;
+
+ /*
+ * Don't let a process set a breakpoint that is not within the
+ * process's address space. If a process could do this, it
+ * could halt the system by setting a breakpoint in the kernel
+ * (if ddb was enabled). Thus, we need to check to make sure
+ * that no breakpoints are being enabled for addresses outside
+ * process's address space.
+ *
+ * XXX - what about when the watched area of the user's
+ * address space is written into from within the kernel
+ * ... wouldn't that still cause a breakpoint to be generated
+ * from within kernel mode?
+ */
+
+ if (DBREG_DR7_ENABLED(dbregs->dr[7], 0)) {
+ /* dr0 is enabled */
+ if (dbregs->dr[0] >= VM_MAXUSER_ADDRESS)
+ return (EINVAL);
+ }
+ if (DBREG_DR7_ENABLED(dbregs->dr[7], 1)) {
+ /* dr1 is enabled */
+ if (dbregs->dr[1] >= VM_MAXUSER_ADDRESS)
+ return (EINVAL);
+ }
+ if (DBREG_DR7_ENABLED(dbregs->dr[7], 2)) {
+ /* dr2 is enabled */
+ if (dbregs->dr[2] >= VM_MAXUSER_ADDRESS)
+ return (EINVAL);
+ }
+ if (DBREG_DR7_ENABLED(dbregs->dr[7], 3)) {
+ /* dr3 is enabled */
+ if (dbregs->dr[3] >= VM_MAXUSER_ADDRESS)
+ return (EINVAL);
+ }
+
+ pcb->pcb_dr0 = dbregs->dr[0];
+ pcb->pcb_dr1 = dbregs->dr[1];
+ pcb->pcb_dr2 = dbregs->dr[2];
+ pcb->pcb_dr3 = dbregs->dr[3];
+ pcb->pcb_dr6 = dbregs->dr[6];
+ pcb->pcb_dr7 = dbregs->dr[7];
+
+ set_pcb_flags(pcb, PCB_DBREGS);
+ }
+
+ return (0);
+}
+
+void
+reset_dbregs(void)
+{
+
+ load_dr7(0); /* Turn off the control bits first */
+ load_dr0(0);
+ load_dr1(0);
+ load_dr2(0);
+ load_dr3(0);
+ load_dr6(0);
+}
+
+/*
+ * Return > 0 if a hardware breakpoint has been hit, and the
+ * breakpoint was in user space. Return 0, otherwise.
+ */
+int
+user_dbreg_trap(register_t dr6)
+{
+ u_int64_t dr7;
+ u_int64_t bp; /* breakpoint bits extracted from dr6 */
+ int nbp; /* number of breakpoints that triggered */
+ caddr_t addr[4]; /* breakpoint addresses */
+ int i;
+
+ bp = dr6 & DBREG_DR6_BMASK;
+ if (bp == 0) {
+ /*
+ * None of the breakpoint bits are set meaning this
+ * trap was not caused by any of the debug registers
+ */
+ return 0;
+ }
+
+ dr7 = rdr7();
+ if ((dr7 & 0x000000ff) == 0) {
+ /*
+ * all GE and LE bits in the dr7 register are zero,
+ * thus the trap couldn't have been caused by the
+ * hardware debug registers
*** 1048 LINES SKIPPED ***
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