提交 a5f6096c 编写于 作者: J Jeff Dike 提交者: Linus Torvalds

uml: floating point signal delivery fixes

Handle floating point state in across signals correctly.  UML/i386 needs to
know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers
hook is added, which on x86_64 does nothing.

UML doesn't save and restore floating point registers on kernel entry and
exit, so they need to be copied between the host process and the sigcontext.
save_fpx_registers and restore_fpx_registers are added for this purpose.
save_fp_registers and restore_fp_registers already exist.

There was a bunch of floating point state conversion code in
arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c,
so it is moved over.

The i386 code now distinguishes between fp and fpx state and handles them
correctly.  The x86_64 code just needs to copy state as-is between the host
process and the stack.  There are also some fixes there to pass the correct
address of the floating point state around.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 189872f9
......@@ -12,6 +12,8 @@
extern void init_thread_registers(struct uml_pt_regs *to);
extern int save_fp_registers(int pid, unsigned long *fp_regs);
extern int restore_fp_registers(int pid, unsigned long *fp_regs);
extern int save_fpx_registers(int pid, unsigned long *fp_regs);
extern int restore_fpx_registers(int pid, unsigned long *fp_regs);
extern void save_registers(int pid, struct uml_pt_regs *regs);
extern void restore_registers(int pid, struct uml_pt_regs *regs);
extern void init_registers(int pid);
......
......@@ -168,4 +168,6 @@ struct syscall_args {
#define UPT_FAULTINFO(r) (&(r)->faultinfo)
extern void arch_init_registers(int pid);
#endif
......@@ -234,4 +234,8 @@ struct syscall_args {
#define UPT_FAULTINFO(r) (&(r)->faultinfo)
static inline void arch_init_registers(int pid)
{
}
#endif
......@@ -47,6 +47,8 @@ void init_registers(int pid)
if (err)
panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
errno);
arch_init_registers(pid);
}
void get_safe_registers(unsigned long *regs)
......
......@@ -8,9 +8,6 @@
#include "longjmp.h"
#include "user.h"
/* XXX These need to use [GS]ETFPXREGS and copy_sc_{to,from}_user_skas needs
* to pass in a sufficiently large buffer
*/
int save_fp_registers(int pid, unsigned long *fp_regs)
{
if(ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
......@@ -25,6 +22,20 @@ int restore_fp_registers(int pid, unsigned long *fp_regs)
return 0;
}
int save_fpx_registers(int pid, unsigned long *fp_regs)
{
if(ptrace(PTRACE_GETFPXREGS, pid, 0, fp_regs) < 0)
return -errno;
return 0;
}
int restore_fpx_registers(int pid, unsigned long *fp_regs)
{
if(ptrace(PTRACE_SETFPXREGS, pid, 0, fp_regs) < 0)
return -errno;
return 0;
}
unsigned long get_thread_reg(int reg, jmp_buf *buf)
{
switch(reg){
......@@ -36,3 +47,21 @@ unsigned long get_thread_reg(int reg, jmp_buf *buf)
return 0;
}
}
int have_fpx_regs = 1;
void arch_init_registers(int pid)
{
unsigned long fpx_regs[HOST_XFP_SIZE];
int err;
err = ptrace(PTRACE_GETFPXREGS, pid, 0, fpx_regs);
if(!err)
return;
if(errno != EIO)
panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
errno);
have_fpx_regs = 0;
}
......@@ -144,85 +144,6 @@ int peek_user(struct task_struct *child, long addr, long data)
return put_user(tmp, (unsigned long __user *) data);
}
struct i387_fxsave_struct {
unsigned short cwd;
unsigned short swd;
unsigned short twd;
unsigned short fop;
long fip;
long fcs;
long foo;
long fos;
long mxcsr;
long reserved;
long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */
long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */
long padding[56];
};
/*
* FPU tag word conversions.
*/
static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
{
unsigned int tmp; /* to avoid 16 bit prefixes in the code */
/* Transform each pair of bits into 01 (valid) or 00 (empty) */
tmp = ~twd;
tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
/* and move the valid bits to the lower byte. */
tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
return tmp;
}
static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
{
struct _fpxreg *st = NULL;
unsigned long twd = (unsigned long) fxsave->twd;
unsigned long tag;
unsigned long ret = 0xffff0000;
int i;
#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16);
for ( i = 0 ; i < 8 ; i++ ) {
if ( twd & 0x1 ) {
st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
switch ( st->exponent & 0x7fff ) {
case 0x7fff:
tag = 2; /* Special */
break;
case 0x0000:
if ( !st->significand[0] &&
!st->significand[1] &&
!st->significand[2] &&
!st->significand[3] ) {
tag = 1; /* Zero */
} else {
tag = 2; /* Special */
}
break;
default:
if ( st->significand[3] & 0x8000 ) {
tag = 0; /* Valid */
} else {
tag = 2; /* Special */
}
break;
}
} else {
tag = 3; /* Empty */
}
ret |= (tag << (2 * i));
twd = twd >> 1;
}
return ret;
}
static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
struct pt_regs *regs)
{
......
......@@ -32,25 +32,186 @@ void copy_sc(struct uml_pt_regs *regs, void *from)
REGS_SS(regs->gp) = sc->ss;
}
/*
* FPU tag word conversions.
*/
static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
{
unsigned int tmp; /* to avoid 16 bit prefixes in the code */
/* Transform each pair of bits into 01 (valid) or 00 (empty) */
tmp = ~twd;
tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
/* and move the valid bits to the lower byte. */
tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
return tmp;
}
static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
{
struct _fpxreg *st = NULL;
unsigned long twd = (unsigned long) fxsave->twd;
unsigned long tag;
unsigned long ret = 0xffff0000;
int i;
#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16);
for (i = 0; i < 8; i++) {
if (twd & 0x1) {
st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
switch (st->exponent & 0x7fff) {
case 0x7fff:
tag = 2; /* Special */
break;
case 0x0000:
if ( !st->significand[0] &&
!st->significand[1] &&
!st->significand[2] &&
!st->significand[3] ) {
tag = 1; /* Zero */
} else {
tag = 2; /* Special */
}
break;
default:
if (st->significand[3] & 0x8000) {
tag = 0; /* Valid */
} else {
tag = 2; /* Special */
}
break;
}
} else {
tag = 3; /* Empty */
}
ret |= (tag << (2 * i));
twd = twd >> 1;
}
return ret;
}
static int convert_fxsr_to_user(struct _fpstate __user *buf,
struct user_fxsr_struct *fxsave)
{
unsigned long env[7];
struct _fpreg __user *to;
struct _fpxreg *from;
int i;
env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
env[2] = twd_fxsr_to_i387(fxsave);
env[3] = fxsave->fip;
env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
env[5] = fxsave->foo;
env[6] = fxsave->fos;
if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
return 1;
to = &buf->_st[0];
from = (struct _fpxreg *) &fxsave->st_space[0];
for (i = 0; i < 8; i++, to++, from++) {
unsigned long __user *t = (unsigned long __user *)to;
unsigned long *f = (unsigned long *)from;
if (__put_user(*f, t) ||
__put_user(*(f + 1), t + 1) ||
__put_user(from->exponent, &to->exponent))
return 1;
}
return 0;
}
static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
struct _fpstate __user *buf)
{
unsigned long env[7];
struct _fpxreg *to;
struct _fpreg __user *from;
int i;
if (copy_from_user( env, buf, 7 * sizeof(long)))
return 1;
fxsave->cwd = (unsigned short)(env[0] & 0xffff);
fxsave->swd = (unsigned short)(env[1] & 0xffff);
fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
fxsave->fip = env[3];
fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
fxsave->fcs = (env[4] & 0xffff);
fxsave->foo = env[5];
fxsave->fos = env[6];
to = (struct _fpxreg *) &fxsave->st_space[0];
from = &buf->_st[0];
for (i = 0; i < 8; i++, to++, from++) {
unsigned long *t = (unsigned long *)to;
unsigned long __user *f = (unsigned long __user *)from;
if (__get_user(*t, f) ||
__get_user(*(t + 1), f + 1) ||
__get_user(to->exponent, &from->exponent))
return 1;
}
return 0;
}
extern int have_fpx_regs;
static int copy_sc_from_user(struct pt_regs *regs,
struct sigcontext __user *from)
{
struct sigcontext sc;
unsigned long fpregs[HOST_FP_SIZE];
struct sigcontext sc;
int err;
err = copy_from_user(&sc, from, sizeof(sc));
err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
if (err)
return err;
copy_sc(&regs->regs, &sc);
err = restore_fp_registers(userspace_pid[0], fpregs);
if (err < 0) {
printk(KERN_ERR "copy_sc_from_user_skas - PTRACE_SETFPREGS "
"failed, errno = %d\n", -err);
return err;
if (have_fpx_regs) {
struct user_fxsr_struct fpx;
err = copy_from_user(&fpx, &sc.fpstate->_fxsr_env[0],
sizeof(struct user_fxsr_struct));
if (err)
return 1;
err = convert_fxsr_from_user(&fpx, sc.fpstate);
if (err)
return 1;
err = restore_fpx_registers(userspace_pid[current_thread->cpu],
(unsigned long *) &fpx);
if (err < 0) {
printk(KERN_ERR "copy_sc_from_user - "
"restore_fpx_registers failed, errno = %d\n",
-err);
return 1;
}
}
else {
struct user_i387_struct fp;
err = copy_from_user(&fp, sc.fpstate,
sizeof(struct user_i387_struct));
if (err)
return 1;
err = restore_fp_registers(userspace_pid[current_thread->cpu],
(unsigned long *) &fp);
if (err < 0) {
printk(KERN_ERR "copy_sc_from_user - "
"restore_fp_registers failed, errno = %d\n",
-err);
return 1;
}
}
return 0;
......@@ -61,7 +222,6 @@ static int copy_sc_to_user(struct sigcontext __user *to,
unsigned long sp)
{
struct sigcontext sc;
unsigned long fpregs[HOST_FP_SIZE];
struct faultinfo * fi = &current->thread.arch.faultinfo;
int err;
......@@ -86,20 +246,43 @@ static int copy_sc_to_user(struct sigcontext __user *to,
sc.err = fi->error_code;
sc.trapno = fi->trap_no;
err = save_fp_registers(userspace_pid[0], fpregs);
if (err < 0) {
printk(KERN_ERR "copy_sc_to_user_skas - PTRACE_GETFPREGS "
"failed, errno = %d\n", err);
return 1;
}
to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
sc.fpstate = to_fp;
if (err)
return err;
if (have_fpx_regs) {
struct user_fxsr_struct fpx;
err = save_fpx_registers(userspace_pid[current_thread->cpu],
(unsigned long *) &fpx);
if (err < 0){
printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
"failed, errno = %d\n", err);
return 1;
}
err = convert_fxsr_to_user(to_fp, &fpx);
if (err)
return 1;
err |= __put_user(fpx.swd, &to_fp->status);
err |= __put_user(X86_FXSR_MAGIC, &to_fp->magic);
if (err)
return 1;
if (copy_to_user(&to_fp->_fxsr_env[0], &fpx,
sizeof(struct user_fxsr_struct)))
return 1;
}
else {
struct user_i387_struct fp;
err = save_fp_registers(userspace_pid[current_thread->cpu],
(unsigned long *) &fp);
if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
return 1;
}
return copy_to_user(to, &sc, sizeof(sc)) ||
copy_to_user(to_fp, fpregs, sizeof(fpregs));
return copy_to_user(to, &sc, sizeof(sc));
}
static int copy_ucontext_to_user(struct ucontext __user *uc,
......
......@@ -42,8 +42,10 @@ void copy_sc(struct uml_pt_regs *regs, void *from)
}
static int copy_sc_from_user(struct pt_regs *regs,
struct sigcontext __user *from)
struct sigcontext __user *from,
struct _fpstate __user *fpp)
{
struct user_i387_struct fp;
int err = 0;
#define GETREG(regs, regno, sc, regname) \
......@@ -69,10 +71,25 @@ static int copy_sc_from_user(struct pt_regs *regs,
err |= GETREG(regs, RIP, from, rip);
err |= GETREG(regs, EFLAGS, from, eflags);
err |= GETREG(regs, CS, from, cs);
if (err)
return 1;
#undef GETREG
return err;
err = copy_from_user(&fp, fpp, sizeof(struct user_i387_struct));
if (err)
return 1;
err = restore_fp_registers(userspace_pid[current_thread->cpu],
(unsigned long *) &fp);
if (err < 0) {
printk(KERN_ERR "copy_sc_from_user - "
"restore_fp_registers failed, errno = %d\n",
-err);
return 1;
}
return 0;
}
static int copy_sc_to_user(struct sigcontext __user *to,
......@@ -80,6 +97,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
unsigned long mask, unsigned long sp)
{
struct faultinfo * fi = &current->thread.arch.faultinfo;
struct user_i387_struct fp;
int err = 0;
err |= __put_user(0, &to->gs);
......@@ -120,6 +138,19 @@ static int copy_sc_to_user(struct sigcontext __user *to,
#undef PUTREG
err |= __put_user(mask, &to->oldmask);
if (err)
return 1;
err = save_fp_registers(userspace_pid[current_thread->cpu],
(unsigned long *) &fp);
if (err < 0) {
printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
"failed, errno = %d\n", -err);
return 1;
}
if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
return 1;
return(err);
}
......@@ -129,6 +160,7 @@ struct rt_sigframe
char __user *pretcode;
struct ucontext uc;
struct siginfo info;
struct _fpstate fpstate;
};
#define round_down(m, n) (((m) / (n)) * (n))
......@@ -138,7 +170,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
siginfo_t *info, sigset_t *set)
{
struct rt_sigframe __user *frame;
struct _fpstate __user *fp = NULL;
unsigned long save_sp = PT_REGS_RSP(regs);
int err = 0;
struct task_struct *me = current;
......@@ -148,13 +179,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
/* Subtract 128 for a red zone and 8 for proper alignment */
frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
goto out;
#if 0 /* XXX */
if (save_i387(fp) < 0)
err |= -1;
#endif
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto out;
......@@ -181,9 +205,9 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
err |= __put_user(sas_ss_flags(save_sp),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0],
save_sp);
err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
set->sig[0], save_sp);
err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
if (sizeof(*set) == 16) {
__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
......@@ -246,7 +270,8 @@ long sys_rt_sigreturn(struct pt_regs *regs)
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext,
&frame->fpstate))
goto segfault;
/* Avoid ERESTART handling */
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册