[linux-2.6-block.git] / arch / powerpc / kernel / signal.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Common signal handling code for both 32 and 64 bits
 *
 *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Corporation
 *    Extracted from signal_32.c and signal_64.c
 */

#include <linux/resume_user_mode.h>
#include <linux/signal.h>
#include <linux/uprobes.h>
#include <linux/key.h>
#include <linux/context_tracking.h>
#include <linux/livepatch.h>
#include <linux/syscalls.h>
#include <asm/hw_breakpoint.h>
#include <linux/uaccess.h>
#include <asm/switch_to.h>
#include <asm/unistd.h>
#include <asm/debug.h>
#include <asm/tm.h>

#include "signal.h"

#ifdef CONFIG_VSX
unsigned long copy_fpr_to_user(void __user *to,
			       struct task_struct *task)
{
	u64 buf[ELF_NFPREG];
	int i;

	/* save FPR copy to local buffer then write to the thread_struct */
	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
		buf[i] = task->thread.TS_FPR(i);
	buf[i] = task->thread.fp_state.fpscr;
	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
}

unsigned long copy_fpr_from_user(struct task_struct *task,
				 void __user *from)
{
	u64 buf[ELF_NFPREG];
	int i;

	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
		return 1;
	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
		task->thread.TS_FPR(i) = buf[i];
	task->thread.fp_state.fpscr = buf[i];

	return 0;
}

unsigned long copy_vsx_to_user(void __user *to,
			       struct task_struct *task)
{
	u64 buf[ELF_NVSRHALFREG];
	int i;

	/* save FPR copy to local buffer then write to the thread_struct */
	for (i = 0; i < ELF_NVSRHALFREG; i++)
		buf[i] = task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET];
	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
}

unsigned long copy_vsx_from_user(struct task_struct *task,
				 void __user *from)
{
	u64 buf[ELF_NVSRHALFREG];
	int i;

	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
		return 1;
	for (i = 0; i < ELF_NVSRHALFREG ; i++)
		task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
	return 0;
}

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
unsigned long copy_ckfpr_to_user(void __user *to,
				  struct task_struct *task)
{
	u64 buf[ELF_NFPREG];
	int i;

	/* save FPR copy to local buffer then write to the thread_struct */
	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
		buf[i] = task->thread.TS_CKFPR(i);
	buf[i] = task->thread.ckfp_state.fpscr;
	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
}

unsigned long copy_ckfpr_from_user(struct task_struct *task,
					  void __user *from)
{
	u64 buf[ELF_NFPREG];
	int i;

	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
		return 1;
	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
		task->thread.TS_CKFPR(i) = buf[i];
	task->thread.ckfp_state.fpscr = buf[i];

	return 0;
}

unsigned long copy_ckvsx_to_user(void __user *to,
				  struct task_struct *task)
{
	u64 buf[ELF_NVSRHALFREG];
	int i;

	/* save FPR copy to local buffer then write to the thread_struct */
	for (i = 0; i < ELF_NVSRHALFREG; i++)
		buf[i] = task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET];
	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
}

unsigned long copy_ckvsx_from_user(struct task_struct *task,
					  void __user *from)
{
	u64 buf[ELF_NVSRHALFREG];
	int i;

	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
		return 1;
	for (i = 0; i < ELF_NVSRHALFREG ; i++)
		task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
	return 0;
}
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
#endif

/* Log an error when sending an unhandled signal to a process. Controlled
 * through debug.exception-trace sysctl.
 */

int show_unhandled_signals = 1;

unsigned long get_min_sigframe_size(void)
{
	if (IS_ENABLED(CONFIG_PPC64))
		return get_min_sigframe_size_64();
	else
		return get_min_sigframe_size_32();
}

#ifdef CONFIG_COMPAT
unsigned long get_min_sigframe_size_compat(void)
{
	return get_min_sigframe_size_32();
}
#endif

/*
 * Allocate space for the signal frame
 */
static unsigned long get_tm_stackpointer(struct task_struct *tsk);

void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
			  size_t frame_size, int is_32)
{
        unsigned long oldsp, newsp;
	unsigned long sp = get_tm_stackpointer(tsk);

        /* Default to using normal stack */
	if (is_32)
		oldsp = sp & 0x0ffffffffUL;
	else
		oldsp = sp;
	oldsp = sigsp(oldsp, ksig);
	newsp = (oldsp - frame_size) & ~0xFUL;

        return (void __user *)newsp;
}

static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
				  int has_handler)
{
	unsigned long ret = regs->gpr[3];
	int restart = 1;

	/* syscall ? */
	if (!trap_is_syscall(regs))
		return;

	if (trap_norestart(regs))
		return;

	/* error signalled ? */
	if (trap_is_scv(regs)) {
		/* 32-bit compat mode sign extend? */
		if (!IS_ERR_VALUE(ret))
			return;
		ret = -ret;
	} else if (!(regs->ccr & 0x10000000)) {
		return;
	}

	switch (ret) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
		/* ERESTARTNOHAND means that the syscall should only be
		 * restarted if there was no handler for the signal, and since
		 * we only get here if there is a handler, we dont restart.
		 */
		restart = !has_handler;
		break;
	case ERESTARTSYS:
		/* ERESTARTSYS means to restart the syscall if there is no
		 * handler or the handler was registered with SA_RESTART
		 */
		restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0;
		break;
	case ERESTARTNOINTR:
		/* ERESTARTNOINTR means that the syscall should be
		 * called again after the signal handler returns.
		 */
		break;
	default:
		return;
	}
	if (restart) {
		if (ret == ERESTART_RESTARTBLOCK)
			regs->gpr[0] = __NR_restart_syscall;
		else
			regs->gpr[3] = regs->orig_gpr3;
		regs_add_return_ip(regs, -4);
		regs->result = 0;
	} else {
		if (trap_is_scv(regs)) {
			regs->result = -EINTR;
			regs->gpr[3] = -EINTR;
		} else {
			regs->result = -EINTR;
			regs->gpr[3] = EINTR;
			regs->ccr |= 0x10000000;
		}
	}
}

static void do_signal(struct task_struct *tsk)
{
	sigset_t *oldset = sigmask_to_save();
	struct ksignal ksig = { .sig = 0 };
	int ret;

	BUG_ON(tsk != current);

	get_signal(&ksig);

	/* Is there any syscall restart business here ? */
	check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0);

	if (ksig.sig <= 0) {
		/* No signal to deliver -- put the saved sigmask back */
		restore_saved_sigmask();
		set_trap_norestart(tsk->thread.regs);
		return;               /* no signals delivered */
	}

        /*
	 * Reenable the DABR before delivering the signal to
	 * user space. The DABR will have been cleared if it
	 * triggered inside the kernel.
	 */
	if (!IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
		int i;

		for (i = 0; i < nr_wp_slots(); i++) {
			if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type)
				__set_breakpoint(i, &tsk->thread.hw_brk[i]);
		}
	}

	/* Re-enable the breakpoints for the signal stack */
	thread_change_pc(tsk, tsk->thread.regs);

	rseq_signal_deliver(&ksig, tsk->thread.regs);

	if (is_32bit_task()) {
        	if (ksig.ka.sa.sa_flags & SA_SIGINFO)
			ret = handle_rt_signal32(&ksig, oldset, tsk);
		else
			ret = handle_signal32(&ksig, oldset, tsk);
	} else {
		ret = handle_rt_signal64(&ksig, oldset, tsk);
	}

	set_trap_norestart(tsk->thread.regs);
	signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP));
}

void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
{
	if (thread_info_flags & _TIF_UPROBE)
		uprobe_notify_resume(regs);

	if (thread_info_flags & _TIF_PATCH_PENDING)
		klp_update_patch_state(current);

	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
		BUG_ON(regs != current->thread.regs);
		do_signal(current);
	}

	if (thread_info_flags & _TIF_NOTIFY_RESUME)
		resume_user_mode_work(regs);
}

static unsigned long get_tm_stackpointer(struct task_struct *tsk)
{
	/* When in an active transaction that takes a signal, we need to be
	 * careful with the stack.  It's possible that the stack has moved back
	 * up after the tbegin.  The obvious case here is when the tbegin is
	 * called inside a function that returns before a tend.  In this case,
	 * the stack is part of the checkpointed transactional memory state.
	 * If we write over this non transactionally or in suspend, we are in
	 * trouble because if we get a tm abort, the program counter and stack
	 * pointer will be back at the tbegin but our in memory stack won't be
	 * valid anymore.
	 *
	 * To avoid this, when taking a signal in an active transaction, we
	 * need to use the stack pointer from the checkpointed state, rather
	 * than the speculated state.  This ensures that the signal context
	 * (written tm suspended) will be written below the stack required for
	 * the rollback.  The transaction is aborted because of the treclaim,
	 * so any memory written between the tbegin and the signal will be
	 * rolled back anyway.
	 *
	 * For signals taken in non-TM or suspended mode, we use the
	 * normal/non-checkpointed stack pointer.
	 */
	struct pt_regs *regs = tsk->thread.regs;
	unsigned long ret = regs->gpr[1];

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
	BUG_ON(tsk != current);

	if (MSR_TM_ACTIVE(regs->msr)) {
		preempt_disable();
		tm_reclaim_current(TM_CAUSE_SIGNAL);
		if (MSR_TM_TRANSACTIONAL(regs->msr))
			ret = tsk->thread.ckpt_regs.gpr[1];

		/*
		 * If we treclaim, we must clear the current thread's TM bits
		 * before re-enabling preemption. Otherwise we might be
		 * preempted and have the live MSR[TS] changed behind our back
		 * (tm_recheckpoint_new_task() would recheckpoint). Besides, we
		 * enter the signal handler in non-transactional state.
		 */
		regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK);
		preempt_enable();
	}
#endif
	return ret;
}

static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";

void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
		  const char *where, void __user *ptr)
{
	if (show_unhandled_signals)
		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
}
Commit	Line	Data
6fcb1397	1	// SPDX-License-Identifier: GPL-2.0-or-later
22e38f29 BH	2	/*
	3	* Common signal handling code for both 32 and 64 bits
	4	*
446957ba	5	* Copyright (c) 2007 Benjamin Herrenschmidt, IBM Corporation
22e38f29	6	* Extracted from signal_32.c and signal_64.c
22e38f29 BH	7	*/
22e38f29 BH	8
03248add	9	#include <linux/resume_user_mode.h>
22e38f29	10	#include <linux/signal.h>
8b7b80b9	11	#include <linux/uprobes.h>
18b246fa	12	#include <linux/key.h>
106ed886	13	#include <linux/context_tracking.h>
a768f784	14	#include <linux/livepatch.h>
3e378680	15	#include <linux/syscalls.h>
06532a67	16	#include <asm/hw_breakpoint.h>
7c0f6ba6	17	#include <linux/uaccess.h>
3dd4eb83	18	#include <asm/switch_to.h>
22e38f29	19	#include <asm/unistd.h>
ae3a197e	20	#include <asm/debug.h>
2b3f8e87	21	#include <asm/tm.h>
22e38f29	22
db277e9a CH	23	#include "signal.h"
db277e9a CH	24
3dd4eb83 MS	25	#ifdef CONFIG_VSX
	26	unsigned long copy_fpr_to_user(void __user *to,
	27	struct task_struct *task)
	28	{
	29	u64 buf[ELF_NFPREG];
	30	int i;
	31
	32	/* save FPR copy to local buffer then write to the thread_struct */
	33	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
	34	buf[i] = task->thread.TS_FPR(i);
	35	buf[i] = task->thread.fp_state.fpscr;
	36	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
	37	}
	38
	39	unsigned long copy_fpr_from_user(struct task_struct *task,
	40	void __user *from)
	41	{
	42	u64 buf[ELF_NFPREG];
	43	int i;
	44
	45	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
	46	return 1;
	47	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
	48	task->thread.TS_FPR(i) = buf[i];
	49	task->thread.fp_state.fpscr = buf[i];
	50
	51	return 0;
	52	}
	53
	54	unsigned long copy_vsx_to_user(void __user *to,
	55	struct task_struct *task)
	56	{
	57	u64 buf[ELF_NVSRHALFREG];
	58	int i;
	59
	60	/* save FPR copy to local buffer then write to the thread_struct */
	61	for (i = 0; i < ELF_NVSRHALFREG; i++)
	62	buf[i] = task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET];
	63	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
	64	}
	65
	66	unsigned long copy_vsx_from_user(struct task_struct *task,
	67	void __user *from)
	68	{
	69	u64 buf[ELF_NVSRHALFREG];
	70	int i;
	71
	72	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
	73	return 1;
	74	for (i = 0; i < ELF_NVSRHALFREG ; i++)
	75	task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
	76	return 0;
	77	}
	78
	79	#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
	80	unsigned long copy_ckfpr_to_user(void __user *to,
	81	struct task_struct *task)
	82	{
	83	u64 buf[ELF_NFPREG];
	84	int i;
	85
	86	/* save FPR copy to local buffer then write to the thread_struct */
	87	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
	88	buf[i] = task->thread.TS_CKFPR(i);
89	buf[i] = task->thread.ckfp_state.fpscr;
90	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
91	}
92
93	unsigned long copy_ckfpr_from_user(struct task_struct *task,
94	void __user *from)
95	{
96	u64 buf[ELF_NFPREG];
97	int i;
98
99	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
100	return 1;
101	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
102	task->thread.TS_CKFPR(i) = buf[i];
103	task->thread.ckfp_state.fpscr = buf[i];
104
105	return 0;
106	}
107
108	unsigned long copy_ckvsx_to_user(void __user *to,
109	struct task_struct *task)
110	{
111	u64 buf[ELF_NVSRHALFREG];
112	int i;
113
114	/* save FPR copy to local buffer then write to the thread_struct */
115	for (i = 0; i < ELF_NVSRHALFREG; i++)
116	buf[i] = task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET];
117	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
118	}
119
120	unsigned long copy_ckvsx_from_user(struct task_struct *task,
121	void __user *from)
122	{
123	u64 buf[ELF_NVSRHALFREG];
124	int i;
125
126	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
127	return 1;
128	for (i = 0; i < ELF_NVSRHALFREG ; i++)
129	task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
130	return 0;
131	}
132	#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
3dd4eb83 MS	133	#endif
3dd4eb83 MS	134
d0c3d534 OJ	135	/* Log an error when sending an unhandled signal to a process. Controlled
	136	* through debug.exception-trace sysctl.
	137	*/
	138
e34166ad	139	int show_unhandled_signals = 1;
d0c3d534	140
2896b2df NP	141	unsigned long get_min_sigframe_size(void)
	142	{
	143	if (IS_ENABLED(CONFIG_PPC64))
	144	return get_min_sigframe_size_64();
	145	else
	146	return get_min_sigframe_size_32();
	147	}
	148
	149	#ifdef CONFIG_COMPAT
	150	unsigned long get_min_sigframe_size_compat(void)
	151	{
	152	return get_min_sigframe_size_32();
	153	}
	154	#endif
	155
a3f61dc0 BH	156	/*
	157	* Allocate space for the signal frame
	158	*/
c180cb30 CL	159	static unsigned long get_tm_stackpointer(struct task_struct *tsk);
	160
	161	void __user get_sigframe(struct ksignal ksig, struct task_struct *tsk,
	162	size_t frame_size, int is_32)
a3f61dc0 BH	163	{
a3f61dc0 BH	164	unsigned long oldsp, newsp;
c180cb30	165	unsigned long sp = get_tm_stackpointer(tsk);
a3f61dc0 BH	166
a3f61dc0 BH	167	/* Default to using normal stack */
0ecbc6ad CL	168	if (is_32)
	169	oldsp = sp & 0x0ffffffffUL;
	170	else
	171	oldsp = sp;
059ade65	172	oldsp = sigsp(oldsp, ksig);
a3f61dc0 BH	173	newsp = (oldsp - frame_size) & ~0xFUL;
a3f61dc0 BH	174
a3f61dc0 BH	175	return (void __user *)newsp;
	176	}
	177
f478f543 CH	178	static void check_syscall_restart(struct pt_regs regs, struct k_sigaction ka,
f478f543 CH	179	int has_handler)
22e38f29 BH	180	{
	181	unsigned long ret = regs->gpr[3];
	182	int restart = 1;
	183
	184	/* syscall ? */
912237ea	185	if (!trap_is_syscall(regs))
22e38f29 BH	186	return;
22e38f29 BH	187
4e0e45b0 NP	188	if (trap_norestart(regs))
	189	return;
	190
22e38f29	191	/* error signalled ? */
7fa95f9a NP	192	if (trap_is_scv(regs)) {
	193	/* 32-bit compat mode sign extend? */
	194	if (!IS_ERR_VALUE(ret))
	195	return;
	196	ret = -ret;
	197	} else if (!(regs->ccr & 0x10000000)) {
22e38f29	198	return;
7fa95f9a	199	}
22e38f29 BH	200
	201	switch (ret) {
	202	case ERESTART_RESTARTBLOCK:
	203	case ERESTARTNOHAND:
	204	/* ERESTARTNOHAND means that the syscall should only be
	205	* restarted if there was no handler for the signal, and since
	206	* we only get here if there is a handler, we dont restart.
	207	*/
	208	restart = !has_handler;
	209	break;
	210	case ERESTARTSYS:
	211	/* ERESTARTSYS means to restart the syscall if there is no
	212	* handler or the handler was registered with SA_RESTART
	213	*/
	214	restart = !has_handler \|\| (ka->sa.sa_flags & SA_RESTART) != 0;
	215	break;
	216	case ERESTARTNOINTR:
	217	/* ERESTARTNOINTR means that the syscall should be
	218	* called again after the signal handler returns.
	219	*/
	220	break;
	221	default:
	222	return;
	223	}
	224	if (restart) {
	225	if (ret == ERESTART_RESTARTBLOCK)
	226	regs->gpr[0] = __NR_restart_syscall;
	227	else
	228	regs->gpr[3] = regs->orig_gpr3;
59dc5bfc	229	regs_add_return_ip(regs, -4);
22e38f29 BH	230	regs->result = 0;
22e38f29 BH	231	} else {
7fa95f9a NP	232	if (trap_is_scv(regs)) {
	233	regs->result = -EINTR;
	234	regs->gpr[3] = -EINTR;
	235	} else {
	236	regs->result = -EINTR;
	237	regs->gpr[3] = EINTR;
	238	regs->ccr \|= 0x10000000;
	239	}
22e38f29 BH	240	}
22e38f29 BH	241	}
69d15f6b	242
d1199431	243	static void do_signal(struct task_struct *tsk)
f478f543	244	{
b7f9a11a	245	sigset_t *oldset = sigmask_to_save();
46725b17	246	struct ksignal ksig = { .sig = 0 };
f478f543	247	int ret;
f478f543	248
d1199431 CB	249	BUG_ON(tsk != current);
d1199431 CB	250
129b69df	251	get_signal(&ksig);
f478f543	252
f478f543	253	/* Is there any syscall restart business here ? */
d1199431	254	check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0);
f478f543	255
129b69df	256	if (ksig.sig <= 0) {
f478f543	257	/* No signal to deliver -- put the saved sigmask back */
51a7b448	258	restore_saved_sigmask();
4e0e45b0	259	set_trap_norestart(tsk->thread.regs);
129b69df	260	return; /* no signals delivered */
f478f543 CH	261	}
f478f543 CH	262
f478f543 CH	263	/*
	264	* Reenable the DABR before delivering the signal to
	265	* user space. The DABR will have been cleared if it
	266	* triggered inside the kernel.
	267	*/
303e6a9d RB	268	if (!IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
	269	int i;
	270
	271	for (i = 0; i < nr_wp_slots(); i++) {
	272	if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type)
	273	__set_breakpoint(i, &tsk->thread.hw_brk[i]);
	274	}
	275	}
	276
06532a67	277	/* Re-enable the breakpoints for the signal stack */
d1199431	278	thread_change_pc(tsk, tsk->thread.regs);
f478f543	279
784e0300	280	rseq_signal_deliver(&ksig, tsk->thread.regs);
8a417c48	281
0a7601b6	282	if (is_32bit_task()) {
129b69df	283	if (ksig.ka.sa.sa_flags & SA_SIGINFO)
d1199431	284	ret = handle_rt_signal32(&ksig, oldset, tsk);
f478f543	285	else
d1199431	286	ret = handle_signal32(&ksig, oldset, tsk);
f478f543	287	} else {
d1199431	288	ret = handle_rt_signal64(&ksig, oldset, tsk);
f478f543 CH	289	}
f478f543 CH	290
4e0e45b0	291	set_trap_norestart(tsk->thread.regs);
129b69df	292	signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP));
f478f543 CH	293	}
f478f543 CH	294
18b246fa	295	void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
7d6d637d	296	{
f57d56dd	297	if (thread_info_flags & _TIF_UPROBE)
8b7b80b9	298	uprobe_notify_resume(regs);
8b7b80b9	299
43347d56 MB	300	if (thread_info_flags & _TIF_PATCH_PENDING)
	301	klp_update_patch_state(current);
	302
900f0713	303	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_NOTIFY_SIGNAL)) {
d1199431 CB	304	BUG_ON(regs != current->thread.regs);
	305	do_signal(current);
	306	}
7d6d637d	307
a68de80f	308	if (thread_info_flags & _TIF_NOTIFY_RESUME)
03248add	309	resume_user_mode_work(regs);
7d6d637d	310	}
2b3f8e87	311
c180cb30	312	static unsigned long get_tm_stackpointer(struct task_struct *tsk)
2b3f8e87 MN	313	{
	314	/* When in an active transaction that takes a signal, we need to be
	315	* careful with the stack. It's possible that the stack has moved back
	316	* up after the tbegin. The obvious case here is when the tbegin is
	317	* called inside a function that returns before a tend. In this case,
	318	* the stack is part of the checkpointed transactional memory state.
	319	* If we write over this non transactionally or in suspend, we are in
	320	* trouble because if we get a tm abort, the program counter and stack
	321	* pointer will be back at the tbegin but our in memory stack won't be
	322	* valid anymore.
	323	*
	324	* To avoid this, when taking a signal in an active transaction, we
	325	* need to use the stack pointer from the checkpointed state, rather
	326	* than the speculated state. This ensures that the signal context
	327	* (written tm suspended) will be written below the stack required for
446957ba	328	* the rollback. The transaction is aborted because of the treclaim,
2b3f8e87 MN	329	* so any memory written between the tbegin and the signal will be
	330	* rolled back anyway.
	331	*
	332	* For signals taken in non-TM or suspended mode, we use the
	333	* normal/non-checkpointed stack pointer.
	334	*/
59dc5bfc NP	335	struct pt_regs *regs = tsk->thread.regs;
59dc5bfc NP	336	unsigned long ret = regs->gpr[1];
2464cc4c	337
2b3f8e87	338	#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
d1199431 CB	339	BUG_ON(tsk != current);
d1199431 CB	340
59dc5bfc	341	if (MSR_TM_ACTIVE(regs->msr)) {
2464cc4c	342	preempt_disable();
d31626f7	343	tm_reclaim_current(TM_CAUSE_SIGNAL);
59dc5bfc	344	if (MSR_TM_TRANSACTIONAL(regs->msr))
2464cc4c GLD	345	ret = tsk->thread.ckpt_regs.gpr[1];
	346
	347	/*
	348	* If we treclaim, we must clear the current thread's TM bits
	349	* before re-enabling preemption. Otherwise we might be
	350	* preempted and have the live MSR[TS] changed behind our back
	351	* (tm_recheckpoint_new_task() would recheckpoint). Besides, we
	352	* enter the signal handler in non-transactional state.
	353	*/
59dc5bfc	354	regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK);
2464cc4c	355	preempt_enable();
2b3f8e87 MN	356	}
2b3f8e87 MN	357	#endif
2464cc4c	358	return ret;
2b3f8e87	359	}
7fe8f773 CL	360
	361	static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
	362	static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";
	363
	364	void signal_fault(struct task_struct tsk, struct pt_regs regs,
	365	const char where, void __user ptr)
	366	{
	367	if (show_unhandled_signals)
	368	printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
	369	task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
	370	}