freebsd-dev/sys/amd64/ia32/ia32_signal.c
Kornel Dulęba f6ac79fb12 Introduce the PROC_SIGCODE() macro
Use a getter macro instead of fetching the sigcode address directly
from a sysent of a given process. It assumes that the sigcode is stored
in the shared page, which is true in all cases, except for a.out
binaries. This will be later useful when the shared page address
randomization is introduced.
No functional change intended.

Approved by:	mw(mentor)
Sponsored by:	Stormshield
Obtained from:	Semihalf
Reviewed by:	kib
Differential Revision: https://reviews.freebsd.org/D35392
2022-07-18 16:27:26 +02:00

965 lines
28 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2003 Peter Wemm
* 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. 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mman.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/resourcevar.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <compat/freebsd32/freebsd32_signal.h>
#include <compat/freebsd32/freebsd32_util.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/freebsd32/freebsd32.h>
#include <compat/ia32/ia32_signal.h>
#include <machine/psl.h>
#include <machine/segments.h>
#include <machine/specialreg.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/cpufunc.h>
#include <machine/trap.h>
#include "vdso_ia32_offsets.h"
extern const char _binary_elf_vdso32_so_1_start[];
extern const char _binary_elf_vdso32_so_1_end[];
extern char _binary_elf_vdso32_so_1_size;
#ifdef COMPAT_FREEBSD4
static void freebsd4_ia32_sendsig(sig_t, ksiginfo_t *, sigset_t *);
#endif
static void
ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp,
char **xfpusave, size_t *xfpusave_len)
{
/*
* XXX Format of 64bit and 32bit FXSAVE areas differs. FXSAVE
* in 32bit mode saves %cs and %ds, while on 64bit it saves
* 64bit instruction and data pointers. Ignore the difference
* for now, it should be irrelevant for most applications.
*/
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 (xfpusave == NULL)
return;
if (!use_xsave || cpu_max_ext_state_size <= sizeof(struct savefpu)) {
*xfpusave_len = 0;
*xfpusave = NULL;
} else {
mcp->mc_flags |= _MC_IA32_HASFPXSTATE;
*xfpusave_len = mcp->mc_xfpustate_len =
cpu_max_ext_state_size - sizeof(struct savefpu);
*xfpusave = (char *)(get_pcb_user_save_td(td) + 1);
}
}
static int
ia32_set_fpcontext(struct thread *td, struct ia32_mcontext *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);
}
/*
* Get machine context.
*/
static int
ia32_get_mcontext(struct thread *td, struct ia32_mcontext *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);
/* Entry into kernel always sets TF_HASSEGS */
mcp->mc_gs = tp->tf_gs;
mcp->mc_fs = tp->tf_fs;
mcp->mc_es = tp->tf_es;
mcp->mc_ds = tp->tf_ds;
mcp->mc_edi = tp->tf_rdi;
mcp->mc_esi = tp->tf_rsi;
mcp->mc_ebp = tp->tf_rbp;
mcp->mc_isp = tp->tf_rsp;
mcp->mc_eflags = tp->tf_rflags;
if (flags & GET_MC_CLEAR_RET) {
mcp->mc_eax = 0;
mcp->mc_edx = 0;
mcp->mc_eflags &= ~PSL_C;
} else {
mcp->mc_eax = tp->tf_rax;
mcp->mc_edx = tp->tf_rdx;
}
mcp->mc_ebx = tp->tf_rbx;
mcp->mc_ecx = tp->tf_rcx;
mcp->mc_eip = tp->tf_rip;
mcp->mc_cs = tp->tf_cs;
mcp->mc_esp = tp->tf_rsp;
mcp->mc_ss = tp->tf_ss;
mcp->mc_len = sizeof(*mcp);
mcp->mc_flags = tp->tf_flags;
ia32_get_fpcontext(td, mcp, NULL, 0);
mcp->mc_fsbase = pcb->pcb_fsbase;
mcp->mc_gsbase = pcb->pcb_gsbase;
mcp->mc_xfpustate = 0;
mcp->mc_xfpustate_len = 0;
bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2));
return (0);
}
/*
* Set machine context.
*
* However, we don't set any but the user modifiable flags, and we won't
* touch the cs selector.
*/
static int
ia32_set_mcontext(struct thread *td, struct ia32_mcontext *mcp)
{
struct trapframe *tp;
char *xfpustate;
long rflags;
int ret;
tp = td->td_frame;
if (mcp->mc_len != sizeof(*mcp))
return (EINVAL);
rflags = (mcp->mc_eflags & PSL_USERCHANGE) |
(tp->tf_rflags & ~PSL_USERCHANGE);
if (mcp->mc_flags & _MC_IA32_HASFPXSTATE) {
if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
sizeof(struct savefpu))
return (EINVAL);
xfpustate = (char *)fpu_save_area_alloc();
ret = copyin(PTRIN(mcp->mc_xfpustate), xfpustate,
mcp->mc_xfpustate_len);
if (ret != 0) {
fpu_save_area_free((struct savefpu *)xfpustate);
return (ret);
}
} else
xfpustate = NULL;
ret = ia32_set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
fpu_save_area_free((struct savefpu *)xfpustate);
if (ret != 0)
return (ret);
tp->tf_gs = mcp->mc_gs;
tp->tf_fs = mcp->mc_fs;
tp->tf_es = mcp->mc_es;
tp->tf_ds = mcp->mc_ds;
tp->tf_flags = TF_HASSEGS;
tp->tf_rdi = mcp->mc_edi;
tp->tf_rsi = mcp->mc_esi;
tp->tf_rbp = mcp->mc_ebp;
tp->tf_rbx = mcp->mc_ebx;
tp->tf_rdx = mcp->mc_edx;
tp->tf_rcx = mcp->mc_ecx;
tp->tf_rax = mcp->mc_eax;
/* trapno, err */
tp->tf_rip = mcp->mc_eip;
tp->tf_rflags = rflags;
tp->tf_rsp = mcp->mc_esp;
tp->tf_ss = mcp->mc_ss;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (0);
}
/*
* The first two fields of a ucontext_t are the signal mask and
* the machine context. The next field is uc_link; we want to
* avoid destroying the link when copying out contexts.
*/
#define UC_COPY_SIZE offsetof(struct ia32_ucontext, uc_link)
int
freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap)
{
struct ia32_ucontext uc;
int ret;
if (uap->ucp == NULL)
ret = EINVAL;
else {
bzero(&uc, sizeof(uc));
ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
PROC_LOCK(td->td_proc);
uc.uc_sigmask = td->td_sigmask;
PROC_UNLOCK(td->td_proc);
ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
}
return (ret);
}
int
freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap)
{
struct ia32_ucontext uc;
int ret;
if (uap->ucp == NULL)
ret = EINVAL;
else {
ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
if (ret == 0) {
ret = ia32_set_mcontext(td, &uc.uc_mcontext);
if (ret == 0) {
kern_sigprocmask(td, SIG_SETMASK,
&uc.uc_sigmask, NULL, 0);
}
}
}
return (ret == 0 ? EJUSTRETURN : ret);
}
int
freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap)
{
struct ia32_ucontext uc;
int ret;
if (uap->oucp == NULL || uap->ucp == NULL)
ret = EINVAL;
else {
bzero(&uc, sizeof(uc));
ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
PROC_LOCK(td->td_proc);
uc.uc_sigmask = td->td_sigmask;
PROC_UNLOCK(td->td_proc);
ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
if (ret == 0) {
ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
if (ret == 0) {
ret = ia32_set_mcontext(td, &uc.uc_mcontext);
if (ret == 0) {
kern_sigprocmask(td, SIG_SETMASK,
&uc.uc_sigmask, NULL, 0);
}
}
}
}
return (ret == 0 ? EJUSTRETURN : ret);
}
/*
* Send an interrupt to process.
*
* Stack is set up to allow sigcode stored
* at top to call routine, followed by kcall
* to sigreturn routine below. After sigreturn
* resets the signal mask, the stack, and the
* frame pointer, it returns to the user
* specified pc, psl.
*/
#ifdef COMPAT_43
static void
ia32_osendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct ia32_osigframe sf, *fp;
struct proc *p;
struct thread *td;
struct sigacts *psp;
struct trapframe *regs;
int sig;
int oonstack;
td = curthread;
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);
/* Allocate space for the signal handler context. */
if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct ia32_osigframe *)((uintptr_t)td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(sf));
td->td_sigstk.ss_flags |= SS_ONSTACK;
} else
fp = (struct ia32_osigframe *)regs->tf_rsp - 1;
/* Build the argument list for the signal handler. */
sf.sf_signum = sig;
sf.sf_scp = (register_t)&fp->sf_siginfo.si_sc;
bzero(&sf.sf_siginfo, sizeof(sf.sf_siginfo));
if (SIGISMEMBER(psp->ps_siginfo, sig)) {
/* Signal handler installed with SA_SIGINFO. */
sf.sf_arg2 = (register_t)&fp->sf_siginfo;
sf.sf_siginfo.si_signo = sig;
sf.sf_siginfo.si_code = ksi->ksi_code;
sf.sf_ah = (uintptr_t)catcher;
sf.sf_addr = 0;
} else {
/* Old FreeBSD-style arguments. */
sf.sf_arg2 = ksi->ksi_code;
sf.sf_addr = (register_t)ksi->ksi_addr;
sf.sf_ah = (uintptr_t)catcher;
}
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(p);
/* Save most if not all of trap frame. */
sf.sf_siginfo.si_sc.sc_eax = regs->tf_rax;
sf.sf_siginfo.si_sc.sc_ebx = regs->tf_rbx;
sf.sf_siginfo.si_sc.sc_ecx = regs->tf_rcx;
sf.sf_siginfo.si_sc.sc_edx = regs->tf_rdx;
sf.sf_siginfo.si_sc.sc_esi = regs->tf_rsi;
sf.sf_siginfo.si_sc.sc_edi = regs->tf_rdi;
sf.sf_siginfo.si_sc.sc_cs = regs->tf_cs;
sf.sf_siginfo.si_sc.sc_ds = regs->tf_ds;
sf.sf_siginfo.si_sc.sc_ss = regs->tf_ss;
sf.sf_siginfo.si_sc.sc_es = regs->tf_es;
sf.sf_siginfo.si_sc.sc_fs = regs->tf_fs;
sf.sf_siginfo.si_sc.sc_gs = regs->tf_gs;
sf.sf_siginfo.si_sc.sc_isp = regs->tf_rsp;
/* Build the signal context to be used by osigreturn(). */
sf.sf_siginfo.si_sc.sc_onstack = (oonstack) ? 1 : 0;
SIG2OSIG(*mask, sf.sf_siginfo.si_sc.sc_mask);
sf.sf_siginfo.si_sc.sc_esp = regs->tf_rsp;
sf.sf_siginfo.si_sc.sc_ebp = regs->tf_rbp;
sf.sf_siginfo.si_sc.sc_eip = regs->tf_rip;
sf.sf_siginfo.si_sc.sc_eflags = regs->tf_rflags;
sf.sf_siginfo.si_sc.sc_trapno = regs->tf_trapno;
sf.sf_siginfo.si_sc.sc_err = regs->tf_err;
/*
* Copy the sigframe out to the user's stack.
*/
if (copyout(&sf, fp, sizeof(*fp)) != 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 = (uintptr_t)fp;
regs->tf_rip = PROC_PS_STRINGS(p) -
(_binary_elf_vdso32_so_1_end - _binary_elf_vdso32_so_1_start) +
VDSO_IA32_OSIGCODE_OFFSET;
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _udatasel;
regs->tf_ss = _udatasel;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
#endif
#ifdef COMPAT_FREEBSD4
static void
freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct ia32_freebsd4_sigframe sf, *sfp;
struct siginfo32 siginfo;
struct proc *p;
struct thread *td;
struct sigacts *psp;
struct trapframe *regs;
int oonstack;
int sig;
td = curthread;
p = td->td_proc;
siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
PROC_LOCK_ASSERT(p, MA_OWNED);
sig = siginfo.si_signo;
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
/* Save user context. */
bzero(&sf, sizeof(sf));
sf.sf_uc.uc_sigmask = *mask;
sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
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;
sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
bzero(sf.sf_uc.uc_mcontext.mc_fpregs,
sizeof(sf.sf_uc.uc_mcontext.mc_fpregs));
bzero(sf.sf_uc.uc_mcontext.__spare__,
sizeof(sf.sf_uc.uc_mcontext.__spare__));
bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));
/* Allocate space for the signal handler context. */
if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
sfp = (struct ia32_freebsd4_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(sf));
} else
sfp = (struct ia32_freebsd4_sigframe *)regs->tf_rsp - 1;
PROC_UNLOCK(p);
/* Build the argument list for the signal handler. */
sf.sf_signum = sig;
sf.sf_ucontext = (register_t)&sfp->sf_uc;
bzero(&sf.sf_si, sizeof(sf.sf_si));
if (SIGISMEMBER(psp->ps_siginfo, sig)) {
/* Signal handler installed with SA_SIGINFO. */
sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
/* Fill in POSIX parts */
sf.sf_si = siginfo;
sf.sf_si.si_signo = sig;
} else {
/* Old FreeBSD-style arguments. */
sf.sf_siginfo = siginfo.si_code;
sf.sf_addr = (u_int32_t)siginfo.si_addr;
sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
}
mtx_unlock(&psp->ps_mtx);
/*
* Copy the sigframe out to the user's stack.
*/
if (copyout(&sf, sfp, sizeof(*sfp)) != 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 = (uintptr_t)sfp;
regs->tf_rip = PROC_SIGCODE(p) +
VDSO_FREEBSD4_IA32_SIGCODE_OFFSET - VDSO_IA32_SIGCODE_OFFSET;
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ss = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
/* leave user %fs and %gs untouched */
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
#endif /* COMPAT_FREEBSD4 */
void
ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct ia32_sigframe sf, *sfp;
struct siginfo32 siginfo;
struct proc *p;
struct thread *td;
struct sigacts *psp;
char *sp;
struct trapframe *regs;
char *xfpusave;
size_t xfpusave_len;
int oonstack;
int sig;
siginfo_to_siginfo32(&ksi->ksi_info, &siginfo);
td = curthread;
p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
sig = siginfo.si_signo;
psp = p->p_sigacts;
#ifdef COMPAT_FREEBSD4
if (SIGISMEMBER(psp->ps_freebsd4, sig)) {
freebsd4_ia32_sendsig(catcher, ksi, mask);
return;
}
#endif
#ifdef COMPAT_43
if (SIGISMEMBER(psp->ps_osigset, sig)) {
ia32_osendsig(catcher, ksi, mask);
return;
}
#endif
mtx_assert(&psp->ps_mtx, MA_OWNED);
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
/* Save user context. */
bzero(&sf, sizeof(sf));
sf.sf_uc.uc_sigmask = *mask;
sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp;
sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
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;
sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi;
sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi;
sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp;
sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */
sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx;
sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx;
sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx;
sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax;
sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno;
sf.sf_uc.uc_mcontext.mc_err = regs->tf_err;
sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip;
sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs;
sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags;
sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp;
sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss;
sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds;
sf.sf_uc.uc_mcontext.mc_es = regs->tf_es;
sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs;
sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs;
sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, &xfpusave, &xfpusave_len);
sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase;
sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase;
/* 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;
else
sp = (char *)regs->tf_rsp;
if (xfpusave != NULL) {
sp -= xfpusave_len;
sp = (char *)((unsigned long)sp & ~0x3Ful);
sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
}
sp -= sizeof(sf);
/* Align to 16 bytes. */
sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF);
PROC_UNLOCK(p);
/* Build the argument list for the signal handler. */
sf.sf_signum = sig;
sf.sf_ucontext = (register_t)&sfp->sf_uc;
bzero(&sf.sf_si, sizeof(sf.sf_si));
if (SIGISMEMBER(psp->ps_siginfo, sig)) {
/* Signal handler installed with SA_SIGINFO. */
sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si;
sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
/* Fill in POSIX parts */
sf.sf_si = siginfo;
sf.sf_si.si_signo = sig;
} else {
/* Old FreeBSD-style arguments. */
sf.sf_siginfo = siginfo.si_code;
sf.sf_addr = (u_int32_t)siginfo.si_addr;
sf.sf_ah = (u_int32_t)(uintptr_t)catcher;
}
mtx_unlock(&psp->ps_mtx);
/*
* Copy the sigframe out to the user's stack.
*/
if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
(xfpusave != NULL && copyout(xfpusave,
PTRIN(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);
}
fpstate_drop(td);
regs->tf_rsp = (uintptr_t)sfp;
regs->tf_rip = PROC_SIGCODE(p);
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ss = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
/* XXXKIB leave user %fs and %gs untouched */
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.
*/
#ifdef COMPAT_43
int
ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
{
struct ia32_osigcontext sc, *scp;
struct trapframe *regs;
int eflags, error;
ksiginfo_t ksi;
regs = td->td_frame;
error = copyin(uap->sigcntxp, &sc, sizeof(sc));
if (error != 0)
return (error);
scp = &sc;
eflags = scp->sc_eflags;
if (!EFL_SECURE(eflags, regs->tf_rflags)) {
return (EINVAL);
}
if (!CS_SECURE(scp->sc_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);
}
regs->tf_ds = scp->sc_ds;
regs->tf_es = scp->sc_es;
regs->tf_fs = scp->sc_fs;
regs->tf_gs = scp->sc_gs;
regs->tf_rax = scp->sc_eax;
regs->tf_rbx = scp->sc_ebx;
regs->tf_rcx = scp->sc_ecx;
regs->tf_rdx = scp->sc_edx;
regs->tf_rsi = scp->sc_esi;
regs->tf_rdi = scp->sc_edi;
regs->tf_cs = scp->sc_cs;
regs->tf_ss = scp->sc_ss;
regs->tf_rbp = scp->sc_ebp;
regs->tf_rsp = scp->sc_esp;
regs->tf_rip = scp->sc_eip;
regs->tf_rflags = eflags;
if (scp->sc_onstack & 1)
td->td_sigstk.ss_flags |= SS_ONSTACK;
else
td->td_sigstk.ss_flags &= ~SS_ONSTACK;
kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
SIGPROCMASK_OLD);
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
#endif
#ifdef COMPAT_FREEBSD4
int
freebsd4_freebsd32_sigreturn(struct thread *td,
struct freebsd4_freebsd32_sigreturn_args *uap)
{
struct ia32_freebsd4_ucontext uc;
struct trapframe *regs;
struct ia32_freebsd4_ucontext *ucp;
int cs, eflags, error;
ksiginfo_t ksi;
error = copyin(uap->sigcntxp, &uc, sizeof(uc));
if (error != 0)
return (error);
ucp = &uc;
regs = td->td_frame;
eflags = ucp->uc_mcontext.mc_eflags;
/*
* Don't allow users to change privileged or reserved flags.
*/
if (!EFL_SECURE(eflags, regs->tf_rflags)) {
uprintf("pid %d (%s): freebsd4_freebsd32_sigreturn eflags = 0x%x\n",
td->td_proc->p_pid, td->td_name, eflags);
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): freebsd4_sigreturn cs = 0x%x\n",
td->td_proc->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);
}
regs->tf_rdi = ucp->uc_mcontext.mc_edi;
regs->tf_rsi = ucp->uc_mcontext.mc_esi;
regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
regs->tf_rdx = ucp->uc_mcontext.mc_edx;
regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
regs->tf_rax = ucp->uc_mcontext.mc_eax;
regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
regs->tf_err = ucp->uc_mcontext.mc_err;
regs->tf_rip = ucp->uc_mcontext.mc_eip;
regs->tf_cs = cs;
regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
regs->tf_rsp = ucp->uc_mcontext.mc_esp;
regs->tf_ss = ucp->uc_mcontext.mc_ss;
regs->tf_ds = ucp->uc_mcontext.mc_ds;
regs->tf_es = ucp->uc_mcontext.mc_es;
regs->tf_fs = ucp->uc_mcontext.mc_fs;
regs->tf_gs = ucp->uc_mcontext.mc_gs;
kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
#endif /* COMPAT_FREEBSD4 */
int
freebsd32_sigreturn(struct thread *td, struct freebsd32_sigreturn_args *uap)
{
struct ia32_ucontext uc;
struct trapframe *regs;
struct ia32_ucontext *ucp;
char *xfpustate;
size_t xfpustate_len;
int cs, eflags, error, ret;
ksiginfo_t ksi;
error = copyin(uap->sigcntxp, &uc, sizeof(uc));
if (error != 0)
return (error);
ucp = &uc;
regs = td->td_frame;
eflags = ucp->uc_mcontext.mc_eflags;
/*
* Don't allow users to change privileged or reserved flags.
*/
if (!EFL_SECURE(eflags, regs->tf_rflags)) {
uprintf("pid %d (%s): freebsd32_sigreturn eflags = 0x%x\n",
td->td_proc->p_pid, td->td_name, eflags);
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",
td->td_proc->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 ((ucp->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",
td->td_proc->p_pid, td->td_name, xfpustate_len);
return (EINVAL);
}
xfpustate = (char *)fpu_save_area_alloc();
error = copyin(PTRIN(ucp->uc_mcontext.mc_xfpustate),
xfpustate, xfpustate_len);
if (error != 0) {
fpu_save_area_free((struct savefpu *)xfpustate);
uprintf(
"pid %d (%s): sigreturn copying xfpustate failed\n",
td->td_proc->p_pid, td->td_name);
return (error);
}
} else {
xfpustate = NULL;
xfpustate_len = 0;
}
ret = ia32_set_fpcontext(td, &ucp->uc_mcontext, xfpustate,
xfpustate_len);
fpu_save_area_free((struct savefpu *)xfpustate);
if (ret != 0) {
uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
td->td_proc->p_pid, td->td_name, ret);
return (ret);
}
regs->tf_rdi = ucp->uc_mcontext.mc_edi;
regs->tf_rsi = ucp->uc_mcontext.mc_esi;
regs->tf_rbp = ucp->uc_mcontext.mc_ebp;
regs->tf_rbx = ucp->uc_mcontext.mc_ebx;
regs->tf_rdx = ucp->uc_mcontext.mc_edx;
regs->tf_rcx = ucp->uc_mcontext.mc_ecx;
regs->tf_rax = ucp->uc_mcontext.mc_eax;
regs->tf_trapno = ucp->uc_mcontext.mc_trapno;
regs->tf_err = ucp->uc_mcontext.mc_err;
regs->tf_rip = ucp->uc_mcontext.mc_eip;
regs->tf_cs = cs;
regs->tf_rflags = ucp->uc_mcontext.mc_eflags;
regs->tf_rsp = ucp->uc_mcontext.mc_esp;
regs->tf_ss = ucp->uc_mcontext.mc_ss;
regs->tf_ds = ucp->uc_mcontext.mc_ds;
regs->tf_es = ucp->uc_mcontext.mc_es;
regs->tf_fs = ucp->uc_mcontext.mc_fs;
regs->tf_gs = ucp->uc_mcontext.mc_gs;
regs->tf_flags = TF_HASSEGS;
kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
/*
* Clear registers on exec
*/
void
ia32_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);
#ifdef COMPAT_43
setup_lcall_gate();
#endif
pcb->pcb_fsbase = 0;
pcb->pcb_gsbase = 0;
pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__;
saved_rflags = regs->tf_rflags & PSL_T;
bzero((char *)regs, sizeof(struct trapframe));
regs->tf_rip = imgp->entry_addr;
regs->tf_rsp = stack;
regs->tf_rflags = PSL_USER | saved_rflags;
regs->tf_ss = _udatasel;
regs->tf_cs = _ucode32sel;
regs->tf_rbx = (register_t)imgp->ps_strings;
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);
fpstate_drop(td);
/* Return via doreti so that we can change to a different %cs */
set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
}