thread_info.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/* thread_info.h: PowerPC low-level thread information
  3 * adapted from the i386 version by Paul Mackerras
  4 *
  5 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
  6 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
  7 */
  8
  9#ifndef _ASM_POWERPC_THREAD_INFO_H
 10#define _ASM_POWERPC_THREAD_INFO_H
 11
 12#include <asm/asm-const.h>
 13#include <asm/page.h>
 14
 15#ifdef __KERNEL__
 16
 17#if defined(CONFIG_KASAN) && CONFIG_THREAD_SHIFT < 15
 18#define MIN_THREAD_SHIFT	(CONFIG_THREAD_SHIFT + 1)
 19#else
 20#define MIN_THREAD_SHIFT	CONFIG_THREAD_SHIFT
 21#endif
 22
 23#if defined(CONFIG_VMAP_STACK) && MIN_THREAD_SHIFT < PAGE_SHIFT
 24#define THREAD_SHIFT		PAGE_SHIFT
 25#else
 26#define THREAD_SHIFT		MIN_THREAD_SHIFT
 27#endif
 28
 29#define THREAD_SIZE		(1 << THREAD_SHIFT)
 30
 31/*
 32 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
 33 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
 34 * assembly.
 35 */
 36#ifdef CONFIG_VMAP_STACK
 37#define THREAD_ALIGN_SHIFT	(THREAD_SHIFT + 1)
 38#else
 39#define THREAD_ALIGN_SHIFT	THREAD_SHIFT
 40#endif
 41
 42#define THREAD_ALIGN		(1 << THREAD_ALIGN_SHIFT)
 43
 44#ifndef __ASSEMBLER__
 45#include <linux/cache.h>
 46#include <asm/processor.h>
 47#include <asm/accounting.h>
 48#include <asm/ppc_asm.h>
 49
 50#define SLB_PRELOAD_NR	16U
 51/*
 52 * low level task data.
 53 */
 54struct thread_info {
 55	int		preempt_count;		/* 0 => preemptable,
 56						   <0 => BUG */
 57#ifdef CONFIG_SMP
 58	unsigned int	cpu;
 59#endif
 60	unsigned long	local_flags;		/* private flags for thread */
 61#ifdef CONFIG_LIVEPATCH_64
 62	unsigned long *livepatch_sp;
 63#endif
 64#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
 65	struct cpu_accounting_data accounting;
 66#endif
 67	unsigned char slb_preload_nr;
 68	unsigned char slb_preload_tail;
 69	u32 slb_preload_esid[SLB_PRELOAD_NR];
 70
 71	/* low level flags - has atomic operations done on it */
 72	unsigned long	flags ____cacheline_aligned_in_smp;
 73};
 74
 75/*
 76 * macros/functions for gaining access to the thread information structure
 77 */
 78#define INIT_THREAD_INFO(tsk)			\
 79{						\
 80	.preempt_count = INIT_PREEMPT_COUNT,	\
 81	.flags =	0,			\
 82}
 83
 84#define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 85
 86/* how to get the thread information struct from C */
 87extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 88
 89void arch_setup_new_exec(void);
 90#define arch_setup_new_exec arch_setup_new_exec
 91
 92#endif /* __ASSEMBLER__ */
 93
 94/*
 95 * thread information flag bit numbers
 96 */
 97#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
 98#define TIF_SIGPENDING		1	/* signal pending */
 99#define TIF_NEED_RESCHED	2	/* rescheduling necessary */
100#define TIF_NOTIFY_SIGNAL	3	/* signal notifications exist */
101#define TIF_SYSCALL_EMU		4	/* syscall emulation active */
102#define TIF_RESTORE_TM		5	/* need to restore TM FP/VEC/VSX */
103#define TIF_PATCH_PENDING	6	/* pending live patching update */
104#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
105#define TIF_SINGLESTEP		8	/* singlestepping active */
106#define TIF_NEED_RESCHED_LAZY	9       /* Scheduler driven lazy preemption */
107#define TIF_SECCOMP		10	/* secure computing */
108#define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */
109#define TIF_NOERROR		12	/* Force successful syscall return */
110#define TIF_NOTIFY_RESUME	13	/* callback before returning to user */
111#define TIF_UPROBE		14	/* breakpointed or single-stepping */
112#define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */
113#define TIF_EMULATE_STACK_STORE	16	/* Is an instruction emulation
114						for stack store? */
115#define TIF_MEMDIE		17	/* is terminating due to OOM killer */
116#if defined(CONFIG_PPC64)
117#define TIF_ELF2ABI		18	/* function descriptors must die! */
118#endif
119#define TIF_POLLING_NRFLAG	19	/* true if poll_idle() is polling TIF_NEED_RESCHED */
120#define TIF_32BIT		20	/* 32 bit binary */
121
122/* as above, but as bit values */
123#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
124#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
125#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
126#define _TIF_NEED_RESCHED_LAZY	(1<<TIF_NEED_RESCHED_LAZY)
127#define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
128#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
129#define _TIF_32BIT		(1<<TIF_32BIT)
130#define _TIF_RESTORE_TM		(1<<TIF_RESTORE_TM)
131#define _TIF_PATCH_PENDING	(1<<TIF_PATCH_PENDING)
132#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
133#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
134#define _TIF_SECCOMP		(1<<TIF_SECCOMP)
135#define _TIF_RESTOREALL		(1<<TIF_RESTOREALL)
136#define _TIF_NOERROR		(1<<TIF_NOERROR)
137#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
138#define _TIF_UPROBE		(1<<TIF_UPROBE)
139#define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
140#define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
141#define _TIF_SYSCALL_EMU	(1<<TIF_SYSCALL_EMU)
142#define _TIF_SYSCALL_DOTRACE	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
143				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
144				 _TIF_SYSCALL_EMU)
145
146#define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
147				 _TIF_NEED_RESCHED_LAZY | _TIF_NOTIFY_RESUME | \
148				 _TIF_UPROBE | _TIF_RESTORE_TM | \
149				 _TIF_PATCH_PENDING | _TIF_NOTIFY_SIGNAL)
150
151#define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
152
153/* Bits in local_flags */
154/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
155#define TLF_NAPPING		0	/* idle thread enabled NAP mode */
156#define TLF_SLEEPING		1	/* suspend code enabled SLEEP mode */
157#define TLF_LAZY_MMU		3	/* tlb_batch is active */
158#define TLF_RUNLATCH		4	/* Is the runlatch enabled? */
159
160#define _TLF_NAPPING		(1 << TLF_NAPPING)
161#define _TLF_SLEEPING		(1 << TLF_SLEEPING)
162#define _TLF_LAZY_MMU		(1 << TLF_LAZY_MMU)
163#define _TLF_RUNLATCH		(1 << TLF_RUNLATCH)
164
165#ifndef __ASSEMBLER__
166
167static inline void clear_thread_local_flags(unsigned int flags)
168{
169	struct thread_info *ti = current_thread_info();
170	ti->local_flags &= ~flags;
171}
172
173static inline bool test_thread_local_flags(unsigned int flags)
174{
175	struct thread_info *ti = current_thread_info();
176	return (ti->local_flags & flags) != 0;
177}
178
179#ifdef CONFIG_COMPAT
180#define is_32bit_task()	(test_thread_flag(TIF_32BIT))
181#define is_tsk_32bit_task(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT))
182#define clear_tsk_compat_task(tsk) (clear_tsk_thread_flag(p, TIF_32BIT))
183#else
184#define is_32bit_task()	(IS_ENABLED(CONFIG_PPC32))
185#define is_tsk_32bit_task(tsk)	(IS_ENABLED(CONFIG_PPC32))
186#define clear_tsk_compat_task(tsk) do { } while (0)
187#endif
188
189#if defined(CONFIG_PPC64)
190#define is_elf2_task() (test_thread_flag(TIF_ELF2ABI))
191#else
192#define is_elf2_task() (0)
193#endif
194
195/*
196 * Walks up the stack frames to make sure that the specified object is
197 * entirely contained by a single stack frame.
198 *
199 * Returns:
200 *	GOOD_FRAME	if within a frame
201 *	BAD_STACK	if placed across a frame boundary (or outside stack)
202 */
203static inline int arch_within_stack_frames(const void * const stack,
204					   const void * const stackend,
205					   const void *obj, unsigned long len)
206{
207	const void *params;
208	const void *frame;
209
210	params = *(const void * const *)current_stack_pointer + STACK_FRAME_PARAMS;
211	frame = **(const void * const * const *)current_stack_pointer;
212
213	/*
214	 * low -----------------------------------------------------------> high
215	 * [backchain][metadata][params][local vars][saved registers][backchain]
216	 *                      ^------------------------------------^
217	 *                      |  allows copies only in this region |
218	 *                      |                                    |
219	 *                    params                               frame
220	 * The metadata region contains the saved LR, CR etc.
221	 */
222	while (stack <= frame && frame < stackend) {
223		if (obj + len <= frame)
224			return obj >= params ? GOOD_FRAME : BAD_STACK;
225		params = frame + STACK_FRAME_PARAMS;
226		frame = *(const void * const *)frame;
227	}
228
229	return BAD_STACK;
230}
231
232#ifdef CONFIG_PPC32
233extern void *emergency_ctx[];
234#endif
235
236#endif	/* !__ASSEMBLER__ */
237
238#endif /* __KERNEL__ */
239
240#endif /* _ASM_POWERPC_THREAD_INFO_H */