[deliverable/linux.git] / arch / um / sys-x86 / signal_64.c

/*
 * Copyright (C) 2003 PathScale, Inc.
 * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/kernel.h>
#include <asm/unistd.h>
#include <asm/uaccess.h>
#include <asm/ucontext.h>
#include "frame_kern.h"
#include "skas.h"

static int copy_sc_from_user(struct pt_regs *regs,
			     struct sigcontext __user *from)
{
	struct sigcontext sc;
	struct user_i387_struct fp;
	void __user *buf;
	int err;

	err = copy_from_user(&sc, from, sizeof(sc));
	if (err)
		return err;

#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname

	GETREG(R8, r8);
	GETREG(R9, r9);
	GETREG(R10, r10);
	GETREG(R11, r11);
	GETREG(R12, r12);
	GETREG(R13, r13);
	GETREG(R14, r14);
	GETREG(R15, r15);
	GETREG(RDI, di);
	GETREG(RSI, si);
	GETREG(RBP, bp);
	GETREG(RBX, bx);
	GETREG(RDX, dx);
	GETREG(RAX, ax);
	GETREG(RCX, cx);
	GETREG(SP, sp);
	GETREG(IP, ip);
	GETREG(EFLAGS, flags);
	GETREG(CS, cs);
#undef GETREG

	buf = sc.fpstate;

	err = copy_from_user(&fp, buf, sizeof(struct user_i387_struct));
	if (err)
		return 1;

	err = restore_fp_registers(userspace_pid[current_thread_info()->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,
			   struct _fpstate __user *to_fp, struct pt_regs *regs,
			   unsigned long mask, unsigned long sp)
{
	struct faultinfo * fi = &current->thread.arch.faultinfo;
	struct sigcontext sc;
	struct user_i387_struct fp;
	int err = 0;
	memset(&sc, 0, sizeof(struct sigcontext));

#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]

	PUTREG(RDI, di);
	PUTREG(RSI, si);
	PUTREG(RBP, bp);
	/*
	 * Must use original RSP, which is passed in, rather than what's in
	 * signal frame.
	 */
	sc.sp = sp;
	PUTREG(RBX, bx);
	PUTREG(RDX, dx);
	PUTREG(RCX, cx);
	PUTREG(RAX, ax);
	PUTREG(R8, r8);
	PUTREG(R9, r9);
	PUTREG(R10, r10);
	PUTREG(R11, r11);
	PUTREG(R12, r12);
	PUTREG(R13, r13);
	PUTREG(R14, r14);
	PUTREG(R15, r15);
	PUTREG(CS, cs); /* XXX x86_64 doesn't do this */

	sc.cr2 = fi->cr2;
	sc.err = fi->error_code;
	sc.trapno = fi->trap_no;

	PUTREG(IP, ip);
	PUTREG(EFLAGS, flags);
#undef PUTREG

	sc.oldmask = mask;

	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
	if (err)
		return 1;

	err = save_fp_registers(userspace_pid[current_thread_info()->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;
}

struct rt_sigframe
{
	char __user *pretcode;
	struct ucontext uc;
	struct siginfo info;
	struct _fpstate fpstate;
};

int setup_signal_stack_si(unsigned long stack_top, int sig,
			  struct k_sigaction *ka, struct pt_regs * regs,
			  siginfo_t *info, sigset_t *set)
{
	struct rt_sigframe __user *frame;
	unsigned long save_sp = PT_REGS_RSP(regs);
	int err = 0;
	struct task_struct *me = current;

	frame = (struct rt_sigframe __user *)
		round_down(stack_top - sizeof(struct rt_sigframe), 16);
	/* 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, frame, sizeof(*frame)))
		goto out;

	if (ka->sa.sa_flags & SA_SIGINFO) {
		err |= copy_siginfo_to_user(&frame->info, info);
		if (err)
			goto out;
	}

	/*
	 * Update SP now because the page fault handler refuses to extend
	 * the stack if the faulting address is too far below the current
	 * SP, which frame now certainly is.  If there's an error, the original
	 * value is restored on the way out.
	 * When writing the sigcontext to the stack, we have to write the
	 * original value, so that's passed to copy_sc_to_user, which does
	 * the right thing with it.
	 */
	PT_REGS_RSP(regs) = (unsigned long) frame;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	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, &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]);
	}
	else
		err |= __copy_to_user(&frame->uc.uc_sigmask, set,
				      sizeof(*set));

	/*
	 * Set up to return from userspace.  If provided, use a stub
	 * already in userspace.
	 */
	/* x86-64 should always use SA_RESTORER. */
	if (ka->sa.sa_flags & SA_RESTORER)
		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	else
		/* could use a vstub here */
		goto restore_sp;

	if (err)
		goto restore_sp;

	/* Set up registers for signal handler */
	{
		struct exec_domain *ed = current_thread_info()->exec_domain;
		if (unlikely(ed && ed->signal_invmap && sig < 32))
			sig = ed->signal_invmap[sig];
	}

	PT_REGS_RDI(regs) = sig;
	/* In case the signal handler was declared without prototypes */
	PT_REGS_RAX(regs) = 0;

	/*
	 * This also works for non SA_SIGINFO handlers because they expect the
	 * next argument after the signal number on the stack.
	 */
	PT_REGS_RSI(regs) = (unsigned long) &frame->info;
	PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
	PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
 out:
	return err;

restore_sp:
	PT_REGS_RSP(regs) = save_sp;
	return err;
}

long sys_rt_sigreturn(struct pt_regs *regs)
{
	unsigned long sp = PT_REGS_SP(&current->thread.regs);
	struct rt_sigframe __user *frame =
		(struct rt_sigframe __user *)(sp - 8);
	struct ucontext __user *uc = &frame->uc;
	sigset_t set;

	if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
		goto segfault;

	sigdelsetmask(&set, ~_BLOCKABLE);
	set_current_blocked(&set);

	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
		goto segfault;

	/* Avoid ERESTART handling */
	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
	return PT_REGS_SYSCALL_RET(&current->thread.regs);

 segfault:
	force_sig(SIGSEGV, current);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* Copyright (C) 2003 PathScale, Inc.
f0c4cad9	3	* Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
1da177e4 LT	4	* Licensed under the GPL
	5	*/
	6
7796931f JD	7	#include <linux/personality.h>
7796931f JD	8	#include <linux/ptrace.h>
0df6e940	9	#include <linux/kernel.h>
7796931f JD	10	#include <asm/unistd.h>
	11	#include <asm/uaccess.h>
	12	#include <asm/ucontext.h>
1da177e4	13	#include "frame_kern.h"
1da177e4 LT	14	#include "skas.h"
1da177e4 LT	15
77bf4400	16	static int copy_sc_from_user(struct pt_regs *regs,
3c916fec	17	struct sigcontext __user *from)
1da177e4	18	{
a955bd61	19	struct sigcontext sc;
a5f6096c	20	struct user_i387_struct fp;
3c916fec	21	void __user *buf;
a955bd61	22	int err;
ba180fd4	23
a955bd61	24	err = copy_from_user(&sc, from, sizeof(sc));
a5f6096c	25	if (err)
a955bd61 AV	26	return err;
	27
	28	#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
	29
	30	GETREG(R8, r8);
	31	GETREG(R9, r9);
	32	GETREG(R10, r10);
	33	GETREG(R11, r11);
	34	GETREG(R12, r12);
	35	GETREG(R13, r13);
	36	GETREG(R14, r14);
	37	GETREG(R15, r15);
	38	GETREG(RDI, di);
	39	GETREG(RSI, si);
	40	GETREG(RBP, bp);
	41	GETREG(RBX, bx);
	42	GETREG(RDX, dx);
	43	GETREG(RAX, ax);
	44	GETREG(RCX, cx);
	45	GETREG(SP, sp);
	46	GETREG(IP, ip);
	47	GETREG(EFLAGS, flags);
	48	GETREG(CS, cs);
1da177e4 LT	49	#undef GETREG
1da177e4 LT	50
a955bd61	51	buf = sc.fpstate;
3c916fec AV	52
3c916fec AV	53	err = copy_from_user(&fp, buf, sizeof(struct user_i387_struct));
a5f6096c JD	54	if (err)
	55	return 1;
	56
a5a678c8	57	err = restore_fp_registers(userspace_pid[current_thread_info()->cpu],
a5f6096c JD	58	(unsigned long *) &fp);
	59	if (err < 0) {
	60	printk(KERN_ERR "copy_sc_from_user - "
	61	"restore_fp_registers failed, errno = %d\n",
	62	-err);
	63	return 1;
	64	}
	65
	66	return 0;
1da177e4 LT	67	}
1da177e4 LT	68
77bf4400 JD	69	static int copy_sc_to_user(struct sigcontext __user *to,
	70	struct _fpstate __user to_fp, struct pt_regs regs,
	71	unsigned long mask, unsigned long sp)
1da177e4	72	{
ba180fd4	73	struct faultinfo * fi = &current->thread.arch.faultinfo;
a955bd61	74	struct sigcontext sc;
a5f6096c	75	struct user_i387_struct fp;
1da177e4	76	int err = 0;
a955bd61	77	memset(&sc, 0, sizeof(struct sigcontext));
1da177e4	78
a955bd61	79	#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
1da177e4	80
a955bd61 AV	81	PUTREG(RDI, di);
	82	PUTREG(RSI, si);
	83	PUTREG(RBP, bp);
f0c4cad9	84	/*
9cd3704f	85	* Must use original RSP, which is passed in, rather than what's in
ba180fd4 JD	86	* signal frame.
ba180fd4 JD	87	*/
a955bd61 AV	88	sc.sp = sp;
	89	PUTREG(RBX, bx);
	90	PUTREG(RDX, dx);
	91	PUTREG(RCX, cx);
	92	PUTREG(RAX, ax);
	93	PUTREG(R8, r8);
	94	PUTREG(R9, r9);
	95	PUTREG(R10, r10);
	96	PUTREG(R11, r11);
	97	PUTREG(R12, r12);
	98	PUTREG(R13, r13);
	99	PUTREG(R14, r14);
	100	PUTREG(R15, r15);
	101	PUTREG(CS, cs); /* XXX x86_64 doesn't do this */
	102
	103	sc.cr2 = fi->cr2;
	104	sc.err = fi->error_code;
	105	sc.trapno = fi->trap_no;
	106
	107	PUTREG(IP, ip);
	108	PUTREG(EFLAGS, flags);
1da177e4 LT	109	#undef PUTREG
1da177e4 LT	110
a955bd61 AV	111	sc.oldmask = mask;
	112
	113	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
a5f6096c JD	114	if (err)
	115	return 1;
	116
a5a678c8	117	err = save_fp_registers(userspace_pid[current_thread_info()->cpu],
a5f6096c JD	118	(unsigned long *) &fp);
	119	if (err < 0) {
	120	printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
	121	"failed, errno = %d\n", -err);
	122	return 1;
	123	}
	124
	125	if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
	126	return 1;
1da177e4	127
f0c4cad9	128	return err;
1da177e4 LT	129	}
1da177e4 LT	130
1da177e4 LT	131	struct rt_sigframe
1da177e4 LT	132	{
ba180fd4 JD	133	char __user *pretcode;
	134	struct ucontext uc;
	135	struct siginfo info;
a5f6096c	136	struct _fpstate fpstate;
1da177e4 LT	137	};
1da177e4 LT	138
1da177e4 LT	139	int setup_signal_stack_si(unsigned long stack_top, int sig,
	140	struct k_sigaction ka, struct pt_regs regs,
	141	siginfo_t info, sigset_t set)
	142	{
	143	struct rt_sigframe __user *frame;
98c18238	144	unsigned long save_sp = PT_REGS_RSP(regs);
1da177e4 LT	145	int err = 0;
	146	struct task_struct *me = current;
	147
	148	frame = (struct rt_sigframe __user *)
3896625d JD	149	round_down(stack_top - sizeof(struct rt_sigframe), 16);
3896625d JD	150	/* Subtract 128 for a red zone and 8 for proper alignment */
ba180fd4	151	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
1da177e4	152
1da177e4 LT	153	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	154	goto out;
	155
	156	if (ka->sa.sa_flags & SA_SIGINFO) {
	157	err \|= copy_siginfo_to_user(&frame->info, info);
	158	if (err)
	159	goto out;
	160	}
	161
f0c4cad9 JD	162	/*
f0c4cad9 JD	163	* Update SP now because the page fault handler refuses to extend
98c18238 JD	164	* the stack if the faulting address is too far below the current
	165	* SP, which frame now certainly is. If there's an error, the original
	166	* value is restored on the way out.
	167	* When writing the sigcontext to the stack, we have to write the
	168	* original value, so that's passed to copy_sc_to_user, which does
	169	* the right thing with it.
	170	*/
	171	PT_REGS_RSP(regs) = (unsigned long) frame;
	172
1da177e4 LT	173	/* Create the ucontext. */
	174	err \|= __put_user(0, &frame->uc.uc_flags);
	175	err \|= __put_user(0, &frame->uc.uc_link);
	176	err \|= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
98c18238	177	err \|= __put_user(sas_ss_flags(save_sp),
1da177e4 LT	178	&frame->uc.uc_stack.ss_flags);
1da177e4 LT	179	err \|= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
a5f6096c JD	180	err \|= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
	181	set->sig[0], save_sp);
	182	err \|= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
1da177e4 LT	183	if (sizeof(*set) == 16) {
	184	__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
	185	__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
	186	}
	187	else
	188	err \|= __copy_to_user(&frame->uc.uc_sigmask, set,
	189	sizeof(*set));
	190
f0c4cad9 JD	191	/*
	192	* Set up to return from userspace. If provided, use a stub
	193	* already in userspace.
	194	*/
1da177e4 LT	195	/* x86-64 should always use SA_RESTORER. */
	196	if (ka->sa.sa_flags & SA_RESTORER)
	197	err \|= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	198	else
	199	/* could use a vstub here */
98c18238	200	goto restore_sp;
1da177e4 LT	201
1da177e4 LT	202	if (err)
98c18238	203	goto restore_sp;
1da177e4 LT	204
	205	/* Set up registers for signal handler */
	206	{
	207	struct exec_domain *ed = current_thread_info()->exec_domain;
	208	if (unlikely(ed && ed->signal_invmap && sig < 32))
	209	sig = ed->signal_invmap[sig];
	210	}
	211
	212	PT_REGS_RDI(regs) = sig;
	213	/* In case the signal handler was declared without prototypes */
	214	PT_REGS_RAX(regs) = 0;
	215
f0c4cad9 JD	216	/*
	217	* This also works for non SA_SIGINFO handlers because they expect the
	218	* next argument after the signal number on the stack.
	219	*/
1da177e4 LT	220	PT_REGS_RSI(regs) = (unsigned long) &frame->info;
	221	PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
	222	PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
1da177e4	223	out:
98c18238 JD	224	return err;
	225
	226	restore_sp:
	227	PT_REGS_RSP(regs) = save_sp;
	228	return err;
1da177e4 LT	229	}
	230
	231	long sys_rt_sigreturn(struct pt_regs *regs)
	232	{
	233	unsigned long sp = PT_REGS_SP(&current->thread.regs);
	234	struct rt_sigframe __user *frame =
	235	(struct rt_sigframe __user *)(sp - 8);
	236	struct ucontext __user *uc = &frame->uc;
	237	sigset_t set;
	238
ba180fd4	239	if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
1da177e4 LT	240	goto segfault;
	241
	242	sigdelsetmask(&set, ~_BLOCKABLE);
78722a44	243	set_current_blocked(&set);
1da177e4	244
3c916fec	245	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
1da177e4 LT	246	goto segfault;
	247
	248	/* Avoid ERESTART handling */
	249	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
f0c4cad9	250	return PT_REGS_SYSCALL_RET(&current->thread.regs);
1da177e4 LT	251
	252	segfault:
	253	force_sig(SIGSEGV, current);
	254	return 0;
	255	}