freebsd-skq/sys/amd64/ia32/ia32_reg.c
kib e2f56205b5 Remove several write-only variables, all reported by the gcc 4.9
buildkernel run.

Some of them were write-only under some kernel options, e.g. variables
keeping values only used by CTR() macros.  It costs nothing to the
code readability and correctness to eliminate the warnings in those
cases too by removing the local cached values used only for
single-access.

Review:	https://reviews.freebsd.org/D2665
Reviewed by:	rodrigc
Looked at by:	bjk
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-05-29 13:24:17 +00:00

232 lines
6.0 KiB
C

/*-
* Copyright (c) 2005 Peter Wemm
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#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/pioctl.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/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_util.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <machine/fpu.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>
#define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
#define EFL_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
int
fill_regs32(struct thread *td, struct reg32 *regs)
{
struct trapframe *tp;
tp = td->td_frame;
if (tp->tf_flags & TF_HASSEGS) {
regs->r_gs = tp->tf_gs;
regs->r_fs = tp->tf_fs;
regs->r_es = tp->tf_es;
regs->r_ds = tp->tf_ds;
} else {
regs->r_gs = _ugssel;
regs->r_fs = _ufssel;
regs->r_es = _udatasel;
regs->r_ds = _udatasel;
}
regs->r_edi = tp->tf_rdi;
regs->r_esi = tp->tf_rsi;
regs->r_ebp = tp->tf_rbp;
regs->r_ebx = tp->tf_rbx;
regs->r_edx = tp->tf_rdx;
regs->r_ecx = tp->tf_rcx;
regs->r_eax = tp->tf_rax;
regs->r_eip = tp->tf_rip;
regs->r_cs = tp->tf_cs;
regs->r_eflags = tp->tf_rflags;
regs->r_esp = tp->tf_rsp;
regs->r_ss = tp->tf_ss;
return (0);
}
int
set_regs32(struct thread *td, struct reg32 *regs)
{
struct trapframe *tp;
tp = td->td_frame;
if (!EFL_SECURE(regs->r_eflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
return (EINVAL);
tp->tf_gs = regs->r_gs;
tp->tf_fs = regs->r_fs;
tp->tf_es = regs->r_es;
tp->tf_ds = regs->r_ds;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
tp->tf_flags = TF_HASSEGS;
tp->tf_rdi = regs->r_edi;
tp->tf_rsi = regs->r_esi;
tp->tf_rbp = regs->r_ebp;
tp->tf_rbx = regs->r_ebx;
tp->tf_rdx = regs->r_edx;
tp->tf_rcx = regs->r_ecx;
tp->tf_rax = regs->r_eax;
tp->tf_rip = regs->r_eip;
tp->tf_cs = regs->r_cs;
tp->tf_rflags = regs->r_eflags;
tp->tf_rsp = regs->r_esp;
tp->tf_ss = regs->r_ss;
return (0);
}
int
fill_fpregs32(struct thread *td, struct fpreg32 *regs)
{
struct savefpu *sv_fpu;
struct save87 *sv_87;
struct env87 *penv_87;
struct envxmm *penv_xmm;
int i;
bzero(regs, sizeof(*regs));
sv_87 = (struct save87 *)regs;
penv_87 = &sv_87->sv_env;
fpugetregs(td);
sv_fpu = get_pcb_user_save_td(td);
penv_xmm = &sv_fpu->sv_env;
/* FPU control/status */
penv_87->en_cw = penv_xmm->en_cw;
penv_87->en_sw = penv_xmm->en_sw;
penv_87->en_tw = penv_xmm->en_tw;
/*
* XXX for en_fip/fcs/foo/fos, check if the fxsave format
* uses the old-style layout for 32 bit user apps. If so,
* read the ip and operand segment registers from there.
* For now, use the process's %cs/%ds.
*/
penv_87->en_fip = penv_xmm->en_rip;
penv_87->en_fcs = td->td_frame->tf_cs;
penv_87->en_opcode = penv_xmm->en_opcode;
penv_87->en_foo = penv_xmm->en_rdp;
/* Entry into the kernel always sets TF_HASSEGS */
penv_87->en_fos = td->td_frame->tf_ds;
/* FPU registers */
for (i = 0; i < 8; ++i)
sv_87->sv_ac[i] = sv_fpu->sv_fp[i].fp_acc;
return (0);
}
int
set_fpregs32(struct thread *td, struct fpreg32 *regs)
{
struct save87 *sv_87 = (struct save87 *)regs;
struct env87 *penv_87 = &sv_87->sv_env;
struct savefpu *sv_fpu = get_pcb_user_save_td(td);
struct envxmm *penv_xmm = &sv_fpu->sv_env;
int i;
/* FPU control/status */
penv_xmm->en_cw = penv_87->en_cw;
penv_xmm->en_sw = penv_87->en_sw;
penv_xmm->en_tw = penv_87->en_tw;
penv_xmm->en_rip = penv_87->en_fip;
/* penv_87->en_fcs and en_fos ignored, see above */
penv_xmm->en_opcode = penv_87->en_opcode;
penv_xmm->en_rdp = penv_87->en_foo;
/* FPU registers */
for (i = 0; i < 8; ++i)
sv_fpu->sv_fp[i].fp_acc = sv_87->sv_ac[i];
for (i = 8; i < 16; ++i)
bzero(&sv_fpu->sv_fp[i].fp_acc, sizeof(sv_fpu->sv_fp[i].fp_acc));
fpuuserinited(td);
return (0);
}
int
fill_dbregs32(struct thread *td, struct dbreg32 *regs)
{
struct dbreg dr;
int err, i;
err = fill_dbregs(td, &dr);
for (i = 0; i < 8; i++)
regs->dr[i] = dr.dr[i];
return (err);
}
int
set_dbregs32(struct thread *td, struct dbreg32 *regs)
{
struct dbreg dr;
int i;
for (i = 0; i < 8; i++)
dr.dr[i] = regs->dr[i];
for (i = 8; i < 16; i++)
dr.dr[i] = 0;
return (set_dbregs(td, &dr));
}