freebsd-dev/sys/i386/linux/linux_ptrace.c
Konstantin Belousov 6cf9a08d2c Introduce the x86 kernel interfaces to allow kernel code to use
FPU/SSE hardware. Caller should provide a save area that is chained
into the stack of the areas; pcb save_area for usermode FPU state is
on top. The pcb now contains a pointer to the current FPU saved area,
used during FPUDNA handling and context switches.  There is also a
facility to allow the kernel thread to use pcb save_area.

Change the dreaded warnings "npxdna in kernel mode!" into the panics
when FPU usage is not registered.

KPI discussed with:	fabient
Tested by:    pho, fabient
Hardware provided by:	Sentex Communications
MFC after:    1 month
2010-06-05 15:59:59 +00:00

487 lines
12 KiB
C

/*-
* Copyright (c) 2001 Alexander Kabaev
* 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
* in this position and unchanged.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 "opt_cpu.h"
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/ptrace.h>
#include <sys/syscallsubr.h>
#include <sys/systm.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/reg.h>
#include <i386/linux/linux.h>
#include <i386/linux/linux_proto.h>
#if !defined(CPU_DISABLE_SSE) && defined(I686_CPU)
#define CPU_ENABLE_SSE
#endif
/*
* Linux ptrace requests numbers. Mostly identical to FreeBSD,
* except for MD ones and PT_ATTACH/PT_DETACH.
*/
#define PTRACE_TRACEME 0
#define PTRACE_PEEKTEXT 1
#define PTRACE_PEEKDATA 2
#define PTRACE_PEEKUSR 3
#define PTRACE_POKETEXT 4
#define PTRACE_POKEDATA 5
#define PTRACE_POKEUSR 6
#define PTRACE_CONT 7
#define PTRACE_KILL 8
#define PTRACE_SINGLESTEP 9
#define PTRACE_ATTACH 16
#define PTRACE_DETACH 17
#define PTRACE_SYSCALL 24
#define PTRACE_GETREGS 12
#define PTRACE_SETREGS 13
#define PTRACE_GETFPREGS 14
#define PTRACE_SETFPREGS 15
#define PTRACE_GETFPXREGS 18
#define PTRACE_SETFPXREGS 19
#define PTRACE_SETOPTIONS 21
/*
* Linux keeps debug registers at the following
* offset in the user struct
*/
#define LINUX_DBREG_OFFSET 252
#define LINUX_DBREG_SIZE (8*sizeof(l_int))
static __inline int
map_signum(int signum)
{
if (signum > 0 && signum <= LINUX_SIGTBLSZ)
signum = linux_to_bsd_signal[_SIG_IDX(signum)];
return ((signum == SIGSTOP)? 0 : signum);
}
struct linux_pt_reg {
l_long ebx;
l_long ecx;
l_long edx;
l_long esi;
l_long edi;
l_long ebp;
l_long eax;
l_int xds;
l_int xes;
l_int xfs;
l_int xgs;
l_long orig_eax;
l_long eip;
l_int xcs;
l_long eflags;
l_long esp;
l_int xss;
};
/*
* Translate i386 ptrace registers between Linux and FreeBSD formats.
* The translation is pretty straighforward, for all registers, but
* orig_eax on Linux side and r_trapno and r_err in FreeBSD
*/
static void
map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
{
linux_r->ebx = bsd_r->r_ebx;
linux_r->ecx = bsd_r->r_ecx;
linux_r->edx = bsd_r->r_edx;
linux_r->esi = bsd_r->r_esi;
linux_r->edi = bsd_r->r_edi;
linux_r->ebp = bsd_r->r_ebp;
linux_r->eax = bsd_r->r_eax;
linux_r->xds = bsd_r->r_ds;
linux_r->xes = bsd_r->r_es;
linux_r->xfs = bsd_r->r_fs;
linux_r->xgs = bsd_r->r_gs;
linux_r->orig_eax = bsd_r->r_eax;
linux_r->eip = bsd_r->r_eip;
linux_r->xcs = bsd_r->r_cs;
linux_r->eflags = bsd_r->r_eflags;
linux_r->esp = bsd_r->r_esp;
linux_r->xss = bsd_r->r_ss;
}
static void
map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
{
bsd_r->r_ebx = linux_r->ebx;
bsd_r->r_ecx = linux_r->ecx;
bsd_r->r_edx = linux_r->edx;
bsd_r->r_esi = linux_r->esi;
bsd_r->r_edi = linux_r->edi;
bsd_r->r_ebp = linux_r->ebp;
bsd_r->r_eax = linux_r->eax;
bsd_r->r_ds = linux_r->xds;
bsd_r->r_es = linux_r->xes;
bsd_r->r_fs = linux_r->xfs;
bsd_r->r_gs = linux_r->xgs;
bsd_r->r_eip = linux_r->eip;
bsd_r->r_cs = linux_r->xcs;
bsd_r->r_eflags = linux_r->eflags;
bsd_r->r_esp = linux_r->esp;
bsd_r->r_ss = linux_r->xss;
}
struct linux_pt_fpreg {
l_long cwd;
l_long swd;
l_long twd;
l_long fip;
l_long fcs;
l_long foo;
l_long fos;
l_long st_space[2*10];
};
static void
map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
{
linux_r->cwd = bsd_r->fpr_env[0];
linux_r->swd = bsd_r->fpr_env[1];
linux_r->twd = bsd_r->fpr_env[2];
linux_r->fip = bsd_r->fpr_env[3];
linux_r->fcs = bsd_r->fpr_env[4];
linux_r->foo = bsd_r->fpr_env[5];
linux_r->fos = bsd_r->fpr_env[6];
bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space));
}
static void
map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
{
bsd_r->fpr_env[0] = linux_r->cwd;
bsd_r->fpr_env[1] = linux_r->swd;
bsd_r->fpr_env[2] = linux_r->twd;
bsd_r->fpr_env[3] = linux_r->fip;
bsd_r->fpr_env[4] = linux_r->fcs;
bsd_r->fpr_env[5] = linux_r->foo;
bsd_r->fpr_env[6] = linux_r->fos;
bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc));
}
struct linux_pt_fpxreg {
l_ushort cwd;
l_ushort swd;
l_ushort twd;
l_ushort fop;
l_long fip;
l_long fcs;
l_long foo;
l_long fos;
l_long mxcsr;
l_long reserved;
l_long st_space[32];
l_long xmm_space[32];
l_long padding[56];
};
#ifdef CPU_ENABLE_SSE
static int
linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
{
PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
return (EIO);
bcopy(&td->td_pcb->pcb_user_save.sv_xmm, fpxregs, sizeof(*fpxregs));
return (0);
}
static int
linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
{
PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
return (EIO);
bcopy(fpxregs, &td->td_pcb->pcb_user_save.sv_xmm, sizeof(*fpxregs));
return (0);
}
#endif
int
linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
{
union {
struct linux_pt_reg reg;
struct linux_pt_fpreg fpreg;
struct linux_pt_fpxreg fpxreg;
} r;
union {
struct reg bsd_reg;
struct fpreg bsd_fpreg;
struct dbreg bsd_dbreg;
} u;
void *addr;
pid_t pid;
int error, req;
error = 0;
/* by default, just copy data intact */
req = uap->req;
pid = (pid_t)uap->pid;
addr = (void *)uap->addr;
switch (req) {
case PTRACE_TRACEME:
case PTRACE_POKETEXT:
case PTRACE_POKEDATA:
case PTRACE_KILL:
error = kern_ptrace(td, req, pid, addr, uap->data);
break;
case PTRACE_PEEKTEXT:
case PTRACE_PEEKDATA: {
/* need to preserve return value */
int rval = td->td_retval[0];
error = kern_ptrace(td, req, pid, addr, 0);
if (error == 0)
error = copyout(td->td_retval, (void *)uap->data,
sizeof(l_int));
td->td_retval[0] = rval;
break;
}
case PTRACE_DETACH:
error = kern_ptrace(td, PT_DETACH, pid, (void *)1,
map_signum(uap->data));
break;
case PTRACE_SINGLESTEP:
case PTRACE_CONT:
error = kern_ptrace(td, req, pid, (void *)1,
map_signum(uap->data));
break;
case PTRACE_ATTACH:
error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data);
break;
case PTRACE_GETREGS:
/* Linux is using data where FreeBSD is using addr */
error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
if (error == 0) {
map_regs_to_linux(&u.bsd_reg, &r.reg);
error = copyout(&r.reg, (void *)uap->data,
sizeof(r.reg));
}
break;
case PTRACE_SETREGS:
/* Linux is using data where FreeBSD is using addr */
error = copyin((void *)uap->data, &r.reg, sizeof(r.reg));
if (error == 0) {
map_regs_from_linux(&u.bsd_reg, &r.reg);
error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
}
break;
case PTRACE_GETFPREGS:
/* Linux is using data where FreeBSD is using addr */
error = kern_ptrace(td, PT_GETFPREGS, pid, &u.bsd_fpreg, 0);
if (error == 0) {
map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
error = copyout(&r.fpreg, (void *)uap->data,
sizeof(r.fpreg));
}
break;
case PTRACE_SETFPREGS:
/* Linux is using data where FreeBSD is using addr */
error = copyin((void *)uap->data, &r.fpreg, sizeof(r.fpreg));
if (error == 0) {
map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
error = kern_ptrace(td, PT_SETFPREGS, pid,
&u.bsd_fpreg, 0);
}
break;
case PTRACE_SETFPXREGS:
#ifdef CPU_ENABLE_SSE
error = copyin((void *)uap->data, &r.fpxreg, sizeof(r.fpxreg));
if (error)
break;
#endif
/* FALL THROUGH */
case PTRACE_GETFPXREGS: {
#ifdef CPU_ENABLE_SSE
struct proc *p;
struct thread *td2;
if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
static int once = 0;
if (!once) {
printf("linux: savexmm != linux_pt_fpxreg\n");
once = 1;
}
error = EIO;
break;
}
if ((p = pfind(uap->pid)) == NULL) {
error = ESRCH;
break;
}
/* Exiting processes can't be debugged. */
if ((p->p_flag & P_WEXIT) != 0) {
error = ESRCH;
goto fail;
}
if ((error = p_candebug(td, p)) != 0)
goto fail;
/* System processes can't be debugged. */
if ((p->p_flag & P_SYSTEM) != 0) {
error = EINVAL;
goto fail;
}
/* not being traced... */
if ((p->p_flag & P_TRACED) == 0) {
error = EPERM;
goto fail;
}
/* not being traced by YOU */
if (p->p_pptr != td->td_proc) {
error = EBUSY;
goto fail;
}
/* not currently stopped */
if (!P_SHOULDSTOP(p) || (p->p_flag & P_WAITED) == 0) {
error = EBUSY;
goto fail;
}
if (req == PTRACE_GETFPXREGS) {
_PHOLD(p); /* may block */
td2 = FIRST_THREAD_IN_PROC(p);
error = linux_proc_read_fpxregs(td2, &r.fpxreg);
_PRELE(p);
PROC_UNLOCK(p);
if (error == 0)
error = copyout(&r.fpxreg, (void *)uap->data,
sizeof(r.fpxreg));
} else {
/* clear dangerous bits exactly as Linux does*/
r.fpxreg.mxcsr &= 0xffbf;
_PHOLD(p); /* may block */
td2 = FIRST_THREAD_IN_PROC(p);
error = linux_proc_write_fpxregs(td2, &r.fpxreg);
_PRELE(p);
PROC_UNLOCK(p);
}
break;
fail:
PROC_UNLOCK(p);
#else
error = EIO;
#endif
break;
}
case PTRACE_PEEKUSR:
case PTRACE_POKEUSR: {
error = EIO;
/* check addr for alignment */
if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
break;
/*
* Allow linux programs to access register values in
* user struct. We simulate this through PT_GET/SETREGS
* as necessary.
*/
if (uap->addr < sizeof(struct linux_pt_reg)) {
error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
if (error != 0)
break;
map_regs_to_linux(&u.bsd_reg, &r.reg);
if (req == PTRACE_PEEKUSR) {
error = copyout((char *)&r.reg + uap->addr,
(void *)uap->data, sizeof(l_int));
break;
}
*(l_int *)((char *)&r.reg + uap->addr) =
(l_int)uap->data;
map_regs_from_linux(&u.bsd_reg, &r.reg);
error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
}
/*
* Simulate debug registers access
*/
if (uap->addr >= LINUX_DBREG_OFFSET &&
uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
error = kern_ptrace(td, PT_GETDBREGS, pid, &u.bsd_dbreg,
0);
if (error != 0)
break;
uap->addr -= LINUX_DBREG_OFFSET;
if (req == PTRACE_PEEKUSR) {
error = copyout((char *)&u.bsd_dbreg +
uap->addr, (void *)uap->data,
sizeof(l_int));
break;
}
*(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
uap->data;
error = kern_ptrace(td, PT_SETDBREGS, pid,
&u.bsd_dbreg, 0);
}
break;
}
case PTRACE_SYSCALL:
/* fall through */
default:
printf("linux: ptrace(%u, ...) not implemented\n",
(unsigned int)uap->req);
error = EINVAL;
break;
}
return (error);
}