[mirror_ubuntu-artful-kernel.git] / arch / x86 / ia32 / ia32_signal.c

/*
 *  linux/arch/x86_64/ia32/ia32_signal.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
 *  2000-12-*   x86-64 compatibility mode signal handling by Andi Kleen
 */

#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/compat.h>
#include <linux/binfmts.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/ptrace.h>
#include <asm/ia32_unistd.h>
#include <asm/user32.h>
#include <uapi/asm/sigcontext.h>
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/sigframe.h>
#include <asm/sighandling.h>
#include <asm/sys_ia32.h>
#include <asm/smap.h>

/*
 * Do a signal return; undo the signal stack.
 */
#define loadsegment_gs(v)	load_gs_index(v)
#define loadsegment_fs(v)	loadsegment(fs, v)
#define loadsegment_ds(v)	loadsegment(ds, v)
#define loadsegment_es(v)	loadsegment(es, v)

#define get_user_seg(seg)	({ unsigned int v; savesegment(seg, v); v; })
#define set_user_seg(seg, v)	loadsegment_##seg(v)

#define COPY(x)			{		\
	get_user_ex(regs->x, &sc->x);		\
}

#define GET_SEG(seg)		({			\
	unsigned short tmp;				\
	get_user_ex(tmp, &sc->seg);			\
	tmp;						\
})

#define COPY_SEG_CPL3(seg)	do {			\
	regs->seg = GET_SEG(seg) | 3;			\
} while (0)

#define RELOAD_SEG(seg)		{		\
	unsigned int pre = GET_SEG(seg);	\
	unsigned int cur = get_user_seg(seg);	\
	pre |= 3;				\
	if (pre != cur)				\
		set_user_seg(seg, pre);		\
}

static int ia32_restore_sigcontext(struct pt_regs *regs,
				   struct sigcontext_32 __user *sc)
{
	unsigned int tmpflags, err = 0;
	void __user *buf;
	u32 tmp;

	/* Always make any pending restarted system calls return -EINTR */
	current->restart_block.fn = do_no_restart_syscall;

	get_user_try {
		/*
		 * Reload fs and gs if they have changed in the signal
		 * handler.  This does not handle long fs/gs base changes in
		 * the handler, but does not clobber them at least in the
		 * normal case.
		 */
		RELOAD_SEG(gs);
		RELOAD_SEG(fs);
		RELOAD_SEG(ds);
		RELOAD_SEG(es);

		COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
		COPY(dx); COPY(cx); COPY(ip); COPY(ax);
		/* Don't touch extended registers */

		COPY_SEG_CPL3(cs);
		COPY_SEG_CPL3(ss);

		get_user_ex(tmpflags, &sc->flags);
		regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
		/* disable syscall checks */
		regs->orig_ax = -1;

		get_user_ex(tmp, &sc->fpstate);
		buf = compat_ptr(tmp);
	} get_user_catch(err);

	err |= fpu__restore_sig(buf, 1);

	force_iret();

	return err;
}

asmlinkage long sys32_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
	sigset_t set;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__get_user(set.sig[0], &frame->sc.oldmask)
	    || (_COMPAT_NSIG_WORDS > 1
		&& __copy_from_user((((char *) &set.sig) + 4),
				    &frame->extramask,
				    sizeof(frame->extramask))))
		goto badframe;

	set_current_blocked(&set);

	if (ia32_restore_sigcontext(regs, &frame->sc))
		goto badframe;
	return regs->ax;

badframe:
	signal_fault(regs, frame, "32bit sigreturn");
	return 0;
}

asmlinkage long sys32_rt_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct rt_sigframe_ia32 __user *frame;
	sigset_t set;

	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	set_current_blocked(&set);

	if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
		goto badframe;

	if (compat_restore_altstack(&frame->uc.uc_stack))
		goto badframe;

	return regs->ax;

badframe:
	signal_fault(regs, frame, "32bit rt sigreturn");
	return 0;
}

/*
 * Set up a signal frame.
 */

static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
				 void __user *fpstate,
				 struct pt_regs *regs, unsigned int mask)
{
	int err = 0;

	put_user_try {
		put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
		put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
		put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
		put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);

		put_user_ex(regs->di, &sc->di);
		put_user_ex(regs->si, &sc->si);
		put_user_ex(regs->bp, &sc->bp);
		put_user_ex(regs->sp, &sc->sp);
		put_user_ex(regs->bx, &sc->bx);
		put_user_ex(regs->dx, &sc->dx);
		put_user_ex(regs->cx, &sc->cx);
		put_user_ex(regs->ax, &sc->ax);
		put_user_ex(current->thread.trap_nr, &sc->trapno);
		put_user_ex(current->thread.error_code, &sc->err);
		put_user_ex(regs->ip, &sc->ip);
		put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
		put_user_ex(regs->flags, &sc->flags);
		put_user_ex(regs->sp, &sc->sp_at_signal);
		put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);

		put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);

		/* non-iBCS2 extensions.. */
		put_user_ex(mask, &sc->oldmask);
		put_user_ex(current->thread.cr2, &sc->cr2);
	} put_user_catch(err);

	return err;
}

/*
 * Determine which stack to use..
 */
static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
				 size_t frame_size,
				 void __user **fpstate)
{
	struct fpu *fpu = &current->thread.fpu;
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->sp;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
		sp = sigsp(sp, ksig);
	/* This is the legacy signal stack switching. */
	else if ((regs->ss & 0xffff) != __USER32_DS &&
		!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
		 ksig->ka.sa.sa_restorer)
		sp = (unsigned long) ksig->ka.sa.sa_restorer;

	if (fpu->fpstate_active) {
		unsigned long fx_aligned, math_size;

		sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
		*fpstate = (struct _fpstate_32 __user *) sp;
		if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
				    math_size) < 0)
			return (void __user *) -1L;
	}

	sp -= frame_size;
	/* Align the stack pointer according to the i386 ABI,
	 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
	sp = ((sp + 4) & -16ul) - 4;
	return (void __user *) sp;
}

int ia32_setup_frame(int sig, struct ksignal *ksig,
		     compat_sigset_t *set, struct pt_regs *regs)
{
	struct sigframe_ia32 __user *frame;
	void __user *restorer;
	int err = 0;
	void __user *fpstate = NULL;

	/* copy_to_user optimizes that into a single 8 byte store */
	static const struct {
		u16 poplmovl;
		u32 val;
		u16 int80;
	} __attribute__((packed)) code = {
		0xb858,		 /* popl %eax ; movl $...,%eax */
		__NR_ia32_sigreturn,
		0x80cd,		/* int $0x80 */
	};

	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	if (__put_user(sig, &frame->sig))
		return -EFAULT;

	if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
		return -EFAULT;

	if (_COMPAT_NSIG_WORDS > 1) {
		if (__copy_to_user(frame->extramask, &set->sig[1],
				   sizeof(frame->extramask)))
			return -EFAULT;
	}

	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
		restorer = ksig->ka.sa.sa_restorer;
	} else {
		/* Return stub is in 32bit vsyscall page */
		if (current->mm->context.vdso)
			restorer = current->mm->context.vdso +
				vdso_image_32.sym___kernel_sigreturn;
		else
			restorer = &frame->retcode;
	}

	put_user_try {
		put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

		/*
		 * These are actually not used anymore, but left because some
		 * gdb versions depend on them as a marker.
		 */
		put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
	} put_user_catch(err);

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	regs->sp = (unsigned long) frame;
	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;

	/* Make -mregparm=3 work */
	regs->ax = sig;
	regs->dx = 0;
	regs->cx = 0;

	loadsegment(ds, __USER32_DS);
	loadsegment(es, __USER32_DS);

	regs->cs = __USER32_CS;
	regs->ss = __USER32_DS;

	return 0;
}

int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
			compat_sigset_t *set, struct pt_regs *regs)
{
	struct rt_sigframe_ia32 __user *frame;
	void __user *restorer;
	int err = 0;
	void __user *fpstate = NULL;

	/* __copy_to_user optimizes that into a single 8 byte store */
	static const struct {
		u8 movl;
		u32 val;
		u16 int80;
		u8  pad;
	} __attribute__((packed)) code = {
		0xb8,
		__NR_ia32_rt_sigreturn,
		0x80cd,
		0,
	};

	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	put_user_try {
		put_user_ex(sig, &frame->sig);
		put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
		put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);

		/* Create the ucontext.  */
		if (boot_cpu_has(X86_FEATURE_XSAVE))
			put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
		else
			put_user_ex(0, &frame->uc.uc_flags);
		put_user_ex(0, &frame->uc.uc_link);
		compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);

		if (ksig->ka.sa.sa_flags & SA_RESTORER)
			restorer = ksig->ka.sa.sa_restorer;
		else
			restorer = current->mm->context.vdso +
				vdso_image_32.sym___kernel_rt_sigreturn;
		put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

		/*
		 * Not actually used anymore, but left because some gdb
		 * versions need it.
		 */
		put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
	} put_user_catch(err);

	err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
	err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
				     regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	regs->sp = (unsigned long) frame;
	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;

	/* Make -mregparm=3 work */
	regs->ax = sig;
	regs->dx = (unsigned long) &frame->info;
	regs->cx = (unsigned long) &frame->uc;

	loadsegment(ds, __USER32_DS);
	loadsegment(es, __USER32_DS);

	regs->cs = __USER32_CS;
	regs->ss = __USER32_DS;

	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/x86_64/ia32/ia32_signal.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*
	6	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	7	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	8	* 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
1da177e4 LT	9	*/
	10
	11	#include <linux/sched.h>
68db0cf1	12	#include <linux/sched/task_stack.h>
1da177e4 LT	13	#include <linux/mm.h>
1da177e4 LT	14	#include <linux/smp.h>
1da177e4	15	#include <linux/kernel.h>
1da177e4 LT	16	#include <linux/errno.h>
1da177e4 LT	17	#include <linux/wait.h>
1da177e4 LT	18	#include <linux/unistd.h>
	19	#include <linux/stddef.h>
	20	#include <linux/personality.h>
	21	#include <linux/compat.h>
9fbbd4dd	22	#include <linux/binfmts.h>
1da177e4	23	#include <asm/ucontext.h>
7c0f6ba6	24	#include <linux/uaccess.h>
78f7f1e5	25	#include <asm/fpu/internal.h>
fcbc99c4	26	#include <asm/fpu/signal.h>
1da177e4 LT	27	#include <asm/ptrace.h>
	28	#include <asm/ia32_unistd.h>
	29	#include <asm/user32.h>
decb4c41	30	#include <uapi/asm/sigcontext.h>
1da177e4	31	#include <asm/proto.h>
af65d648	32	#include <asm/vdso.h>
d98f9d84	33	#include <asm/sigframe.h>
f28f0c23	34	#include <asm/sighandling.h>
2f06de06	35	#include <asm/sys_ia32.h>
49b8c695	36	#include <asm/smap.h>
d98f9d84	37
1da177e4 LT	38	/*
	39	* Do a signal return; undo the signal stack.
	40	*/
a967bb3f HS	41	#define loadsegment_gs(v) load_gs_index(v)
	42	#define loadsegment_fs(v) loadsegment(fs, v)
	43	#define loadsegment_ds(v) loadsegment(ds, v)
	44	#define loadsegment_es(v) loadsegment(es, v)
	45
	46	#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })
	47	#define set_user_seg(seg, v) loadsegment_##seg(v)
	48
b78a5b52	49	#define COPY(x) { \
3b4b7570	50	get_user_ex(regs->x, &sc->x); \
1da177e4	51	}
1da177e4	52
8801ead4 HS	53	#define GET_SEG(seg) ({ \
	54	unsigned short tmp; \
	55	get_user_ex(tmp, &sc->seg); \
	56	tmp; \
	57	})
	58
	59	#define COPY_SEG_CPL3(seg) do { \
	60	regs->seg = GET_SEG(seg) \| 3; \
	61	} while (0)
1da177e4	62
8c6e5ce0	63	#define RELOAD_SEG(seg) { \
a967bb3f HS	64	unsigned int pre = GET_SEG(seg); \
a967bb3f HS	65	unsigned int cur = get_user_seg(seg); \
8c6e5ce0 HS	66	pre \|= 3; \
8c6e5ce0 HS	67	if (pre != cur) \
a967bb3f	68	set_user_seg(seg, pre); \
8c6e5ce0	69	}
99b9cdf7 TG	70
99b9cdf7 TG	71	static int ia32_restore_sigcontext(struct pt_regs *regs,
8fcb346b	72	struct sigcontext_32 __user *sc)
99b9cdf7	73	{
a967bb3f	74	unsigned int tmpflags, err = 0;
ab513701	75	void __user *buf;
99b9cdf7 TG	76	u32 tmp;
	77
	78	/* Always make any pending restarted system calls return -EINTR */
f56141e3	79	current->restart_block.fn = do_no_restart_syscall;
99b9cdf7	80
3b4b7570 HS	81	get_user_try {
	82	/*
	83	* Reload fs and gs if they have changed in the signal
	84	* handler. This does not handle long fs/gs base changes in
	85	* the handler, but does not clobber them at least in the
	86	* normal case.
	87	*/
a967bb3f	88	RELOAD_SEG(gs);
3b4b7570 HS	89	RELOAD_SEG(fs);
	90	RELOAD_SEG(ds);
	91	RELOAD_SEG(es);
	92
	93	COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
6a3713f0	94	COPY(dx); COPY(cx); COPY(ip); COPY(ax);
3b4b7570 HS	95	/* Don't touch extended registers */
	96
	97	COPY_SEG_CPL3(cs);
	98	COPY_SEG_CPL3(ss);
	99
	100	get_user_ex(tmpflags, &sc->flags);
	101	regs->flags = (regs->flags & ~FIX_EFLAGS) \| (tmpflags & FIX_EFLAGS);
	102	/* disable syscall checks */
	103	regs->orig_ax = -1;
	104
	105	get_user_ex(tmp, &sc->fpstate);
	106	buf = compat_ptr(tmp);
3b4b7570 HS	107	} get_user_catch(err);
3b4b7570 HS	108
9dfe99b7	109	err \|= fpu__restore_sig(buf, 1);
5e88353d	110
1daeaa31 BG	111	force_iret();
1daeaa31 BG	112
1da177e4	113	return err;
1da177e4 LT	114	}
1da177e4 LT	115
3fe26fa3	116	asmlinkage long sys32_sigreturn(void)
1da177e4	117	{
3fe26fa3	118	struct pt_regs *regs = current_pt_regs();
3b0d29ee	119	struct sigframe_ia32 __user frame = (struct sigframe_ia32 __user )(regs->sp-8);
1da177e4	120	sigset_t set;
1da177e4 LT	121
	122	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	123	goto badframe;
	124	if (__get_user(set.sig[0], &frame->sc.oldmask)
	125	\|\| (_COMPAT_NSIG_WORDS > 1
99b9cdf7 TG	126	&& __copy_from_user((((char *) &set.sig) + 4),
99b9cdf7 TG	127	&frame->extramask,
1da177e4 LT	128	sizeof(frame->extramask))))
	129	goto badframe;
	130
905f29e2	131	set_current_blocked(&set);
99b9cdf7	132
6a3713f0	133	if (ia32_restore_sigcontext(regs, &frame->sc))
1da177e4	134	goto badframe;
6a3713f0	135	return regs->ax;
1da177e4 LT	136
	137	badframe:
	138	signal_fault(regs, frame, "32bit sigreturn");
	139	return 0;
99b9cdf7	140	}
1da177e4	141
3fe26fa3	142	asmlinkage long sys32_rt_sigreturn(void)
1da177e4	143	{
3fe26fa3	144	struct pt_regs *regs = current_pt_regs();
3b0d29ee	145	struct rt_sigframe_ia32 __user *frame;
1da177e4	146	sigset_t set;
1da177e4	147
3b0d29ee	148	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
1da177e4 LT	149
	150	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	151	goto badframe;
	152	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	153	goto badframe;
	154
905f29e2	155	set_current_blocked(&set);
99b9cdf7	156
6a3713f0	157	if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
1da177e4 LT	158	goto badframe;
1da177e4 LT	159
90268439	160	if (compat_restore_altstack(&frame->uc.uc_stack))
1da177e4 LT	161	goto badframe;
1da177e4 LT	162
6a3713f0	163	return regs->ax;
1da177e4 LT	164
1da177e4 LT	165	badframe:
99b9cdf7	166	signal_fault(regs, frame, "32bit rt sigreturn");
1da177e4	167	return 0;
99b9cdf7	168	}
1da177e4 LT	169
	170	/*
	171	* Set up a signal frame.
	172	*/
	173
8fcb346b	174	static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
ab513701	175	void __user *fpstate,
99b9cdf7	176	struct pt_regs *regs, unsigned int mask)
1da177e4	177	{
a967bb3f	178	int err = 0;
1da177e4	179
3b4b7570	180	put_user_try {
a967bb3f HS	181	put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
	182	put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
	183	put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
	184	put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);
3b4b7570 HS	185
	186	put_user_ex(regs->di, &sc->di);
	187	put_user_ex(regs->si, &sc->si);
	188	put_user_ex(regs->bp, &sc->bp);
	189	put_user_ex(regs->sp, &sc->sp);
	190	put_user_ex(regs->bx, &sc->bx);
	191	put_user_ex(regs->dx, &sc->dx);
	192	put_user_ex(regs->cx, &sc->cx);
	193	put_user_ex(regs->ax, &sc->ax);
51e7dc70	194	put_user_ex(current->thread.trap_nr, &sc->trapno);
3b4b7570 HS	195	put_user_ex(current->thread.error_code, &sc->err);
	196	put_user_ex(regs->ip, &sc->ip);
	197	put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
	198	put_user_ex(regs->flags, &sc->flags);
	199	put_user_ex(regs->sp, &sc->sp_at_signal);
	200	put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
	201
	202	put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);
	203
	204	/* non-iBCS2 extensions.. */
	205	put_user_ex(mask, &sc->oldmask);
	206	put_user_ex(current->thread.cr2, &sc->cr2);
	207	} put_user_catch(err);
1da177e4 LT	208
	209	return err;
	210	}
	211
	212	/*
	213	* Determine which stack to use..
	214	*/
235b8022	215	static void __user get_sigframe(struct ksignal ksig, struct pt_regs *regs,
3c1c7f10	216	size_t frame_size,
0ff8fef4	217	void __user **fpstate)
1da177e4	218	{
c5bedc68	219	struct fpu *fpu = &current->thread.fpu;
65ea5b03	220	unsigned long sp;
1da177e4 LT	221
1da177e4 LT	222	/* Default to using normal stack */
65ea5b03	223	sp = regs->sp;
1da177e4 LT	224
1da177e4 LT	225	/* This is the X/Open sanctioned signal stack switching. */
235b8022 AV	226	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
235b8022 AV	227	sp = sigsp(sp, ksig);
1da177e4	228	/* This is the legacy signal stack switching. */
8bee3f0a	229	else if ((regs->ss & 0xffff) != __USER32_DS &&
235b8022 AV	230	!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
	231	ksig->ka.sa.sa_restorer)
	232	sp = (unsigned long) ksig->ka.sa.sa_restorer;
1da177e4	233
c5bedc68	234	if (fpu->fpstate_active) {
72a671ce SS	235	unsigned long fx_aligned, math_size;
72a671ce SS	236
82c0e45e	237	sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
86e9fc3a	238	fpstate = (struct _fpstate_32 __user ) sp;
c8e14041	239	if (copy_fpstate_to_sigframe(fpstate, (void __user )fx_aligned,
72a671ce	240	math_size) < 0)
99ea1b93	241	return (void __user *) -1L;
3c1c7f10 SS	242	}
3c1c7f10 SS	243
65ea5b03	244	sp -= frame_size;
d347f372 MO	245	/* Align the stack pointer according to the i386 ABI,
d347f372 MO	246	* i.e. so that on function entry ((sp + 4) & 15) == 0. */
65ea5b03 PA	247	sp = ((sp + 4) & -16ul) - 4;
65ea5b03 PA	248	return (void __user *) sp;
1da177e4 LT	249	}
1da177e4 LT	250
235b8022	251	int ia32_setup_frame(int sig, struct ksignal *ksig,
99b9cdf7	252	compat_sigset_t set, struct pt_regs regs)
1da177e4	253	{
3b0d29ee	254	struct sigframe_ia32 __user *frame;
99b9cdf7	255	void __user *restorer;
1da177e4	256	int err = 0;
ab513701	257	void __user *fpstate = NULL;
1da177e4	258
99b9cdf7 TG	259	/* copy_to_user optimizes that into a single 8 byte store */
	260	static const struct {
	261	u16 poplmovl;
	262	u32 val;
	263	u16 int80;
99b9cdf7 TG	264	} __attribute__((packed)) code = {
	265	0xb858, /* popl %eax ; movl $...,%eax */
	266	__NR_ia32_sigreturn,
	267	0x80cd, /* int $0x80 */
99b9cdf7 TG	268	};
99b9cdf7 TG	269
235b8022	270	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
1da177e4 LT	271
1da177e4 LT	272	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
3d0aedd9	273	return -EFAULT;
1da177e4	274
2ba48e16	275	if (__put_user(sig, &frame->sig))
3d0aedd9	276	return -EFAULT;
1da177e4	277
2ba48e16	278	if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
3d0aedd9	279	return -EFAULT;
1da177e4 LT	280
1da177e4 LT	281	if (_COMPAT_NSIG_WORDS > 1) {
2ba48e16 HS	282	if (__copy_to_user(frame->extramask, &set->sig[1],
2ba48e16 HS	283	sizeof(frame->extramask)))
3d0aedd9	284	return -EFAULT;
1da177e4	285	}
1da177e4	286
235b8022 AV	287	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
235b8022 AV	288	restorer = ksig->ka.sa.sa_restorer;
af65d648 RM	289	} else {
af65d648 RM	290	/* Return stub is in 32bit vsyscall page */
1a3e4ca4	291	if (current->mm->context.vdso)
6f121e54	292	restorer = current->mm->context.vdso +
0a6d1fa0	293	vdso_image_32.sym___kernel_sigreturn;
af65d648	294	else
ade1af77	295	restorer = &frame->retcode;
af65d648	296	}
99b9cdf7	297
3b4b7570 HS	298	put_user_try {
	299	put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
	300
	301	/*
	302	* These are actually not used anymore, but left because some
	303	* gdb versions depend on them as a marker.
	304	*/
0ff8fef4	305	put_user_ex(((u64 )&code), (u64 __user *)frame->retcode);
3b4b7570 HS	306	} put_user_catch(err);
3b4b7570 HS	307
1da177e4	308	if (err)
3d0aedd9	309	return -EFAULT;
1da177e4 LT	310
1da177e4 LT	311	/* Set up registers for signal handler */
65ea5b03	312	regs->sp = (unsigned long) frame;
235b8022	313	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
1da177e4	314
536e3ee4	315	/* Make -mregparm=3 work */
65ea5b03 PA	316	regs->ax = sig;
	317	regs->dx = 0;
	318	regs->cx = 0;
536e3ee4	319
b6edbb1e JF	320	loadsegment(ds, __USER32_DS);
b6edbb1e JF	321	loadsegment(es, __USER32_DS);
1da177e4	322
99b9cdf7 TG	323	regs->cs = __USER32_CS;
99b9cdf7 TG	324	regs->ss = __USER32_DS;
1da177e4	325
1d001df1	326	return 0;
1da177e4 LT	327	}
1da177e4 LT	328
235b8022	329	int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
99b9cdf7	330	compat_sigset_t set, struct pt_regs regs)
1da177e4	331	{
3b0d29ee	332	struct rt_sigframe_ia32 __user *frame;
af65d648	333	void __user *restorer;
1da177e4	334	int err = 0;
ab513701	335	void __user *fpstate = NULL;
1da177e4	336
99b9cdf7 TG	337	/* __copy_to_user optimizes that into a single 8 byte store */
	338	static const struct {
	339	u8 movl;
	340	u32 val;
	341	u16 int80;
9cc3c49e	342	u8 pad;
99b9cdf7 TG	343	} __attribute__((packed)) code = {
	344	0xb8,
	345	__NR_ia32_rt_sigreturn,
	346	0x80cd,
	347	0,
	348	};
	349
235b8022	350	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
1da177e4 LT	351
1da177e4 LT	352	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
3d0aedd9	353	return -EFAULT;
1da177e4	354
3b4b7570 HS	355	put_user_try {
	356	put_user_ex(sig, &frame->sig);
	357	put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
	358	put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
1da177e4	359
3b4b7570	360	/* Create the ucontext. */
d366bf7e	361	if (boot_cpu_has(X86_FEATURE_XSAVE))
3b4b7570 HS	362	put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
	363	else
	364	put_user_ex(0, &frame->uc.uc_flags);
	365	put_user_ex(0, &frame->uc.uc_link);
bd1c149a	366	compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
3b4b7570	367
235b8022 AV	368	if (ksig->ka.sa.sa_flags & SA_RESTORER)
235b8022 AV	369	restorer = ksig->ka.sa.sa_restorer;
3b4b7570	370	else
6f121e54	371	restorer = current->mm->context.vdso +
0a6d1fa0	372	vdso_image_32.sym___kernel_rt_sigreturn;
3b4b7570 HS	373	put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
	374
	375	/*
	376	* Not actually used anymore, but left because some gdb
	377	* versions need it.
	378	*/
0ff8fef4	379	put_user_ex(((u64 )&code), (u64 __user *)frame->retcode);
3b4b7570	380	} put_user_catch(err);
1da177e4	381
68463510	382	err \|= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
5e88353d PA	383	err \|= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
	384	regs, set->sig[0]);
	385	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	386
1da177e4	387	if (err)
3d0aedd9	388	return -EFAULT;
1da177e4 LT	389
1da177e4 LT	390	/* Set up registers for signal handler */
65ea5b03	391	regs->sp = (unsigned long) frame;
235b8022	392	regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
1da177e4	393
a7aacdf9	394	/* Make -mregparm=3 work */
65ea5b03 PA	395	regs->ax = sig;
	396	regs->dx = (unsigned long) &frame->info;
	397	regs->cx = (unsigned long) &frame->uc;
a7aacdf9	398
b6edbb1e JF	399	loadsegment(ds, __USER32_DS);
b6edbb1e JF	400	loadsegment(es, __USER32_DS);
99b9cdf7 TG	401
	402	regs->cs = __USER32_CS;
	403	regs->ss = __USER32_DS;
1da177e4	404
1d001df1	405	return 0;
1da177e4	406	}