xref: /linux/arch/powerpc/include/asm/thread_info.h (revision d639d9fa162aadec1ae9980c4dcf6e50bd2f8290)
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  */
54 struct thread_info {
55 	int		preempt_count;		/* 0 => preemptable,
56 						   <0 => BUG */
57 #ifdef CONFIG_SMP
58 	unsigned int	cpu;
59 #endif
60 	unsigned long	syscall_work;		/* SYSCALL_WORK_ flags */
61 	unsigned long	local_flags;		/* private flags for thread */
62 #ifdef CONFIG_LIVEPATCH_64
63 	unsigned long *livepatch_sp;
64 #endif
65 #if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
66 	struct cpu_accounting_data accounting;
67 #endif
68 	unsigned char slb_preload_nr;
69 	unsigned char slb_preload_tail;
70 	u32 slb_preload_esid[SLB_PRELOAD_NR];
71 
72 	/* low level flags - has atomic operations done on it */
73 	unsigned long	flags ____cacheline_aligned_in_smp;
74 };
75 
76 /*
77  * macros/functions for gaining access to the thread information structure
78  */
79 #define INIT_THREAD_INFO(tsk)			\
80 {						\
81 	.preempt_count = INIT_PREEMPT_COUNT,	\
82 	.flags =	0,			\
83 }
84 
85 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
86 
87 /* how to get the thread information struct from C */
88 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
89 
90 void arch_setup_new_exec(void);
91 #define arch_setup_new_exec arch_setup_new_exec
92 
93 #endif /* __ASSEMBLER__ */
94 
95 /*
96  * thread information flag bit numbers
97  */
98 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
99 #define TIF_SIGPENDING		1	/* signal pending */
100 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
101 #define TIF_NOTIFY_SIGNAL	3	/* signal notifications exist */
102 #define TIF_SYSCALL_EMU		4	/* syscall emulation active */
103 #define TIF_RESTORE_TM		5	/* need to restore TM FP/VEC/VSX */
104 #define TIF_PATCH_PENDING	6	/* pending live patching update */
105 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
106 #define TIF_SINGLESTEP		8	/* singlestepping active */
107 #define TIF_NEED_RESCHED_LAZY	9       /* Scheduler driven lazy preemption */
108 #define TIF_SECCOMP		10	/* secure computing */
109 #define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */
110 #define TIF_NOERROR		12	/* Force successful syscall return */
111 #define TIF_NOTIFY_RESUME	13	/* callback before returning to user */
112 #define TIF_UPROBE		14	/* breakpointed or single-stepping */
113 #define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */
114 #define TIF_EMULATE_STACK_STORE	16	/* Is an instruction emulation
115 						for stack store? */
116 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
117 #if defined(CONFIG_PPC64)
118 #define TIF_ELF2ABI		18	/* function descriptors must die! */
119 #endif
120 #define TIF_POLLING_NRFLAG	19	/* true if poll_idle() is polling TIF_NEED_RESCHED */
121 #define TIF_32BIT		20	/* 32 bit binary */
122 
123 /* as above, but as bit values */
124 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
125 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
126 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
127 #define _TIF_NEED_RESCHED_LAZY	(1<<TIF_NEED_RESCHED_LAZY)
128 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
129 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
130 #define _TIF_32BIT		(1<<TIF_32BIT)
131 #define _TIF_RESTORE_TM		(1<<TIF_RESTORE_TM)
132 #define _TIF_PATCH_PENDING	(1<<TIF_PATCH_PENDING)
133 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
134 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
135 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
136 #define _TIF_RESTOREALL		(1<<TIF_RESTOREALL)
137 #define _TIF_NOERROR		(1<<TIF_NOERROR)
138 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
139 #define _TIF_UPROBE		(1<<TIF_UPROBE)
140 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
141 #define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
142 #define _TIF_SYSCALL_EMU	(1<<TIF_SYSCALL_EMU)
143 #define _TIF_SYSCALL_DOTRACE	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
144 				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
145 				 _TIF_SYSCALL_EMU)
146 
147 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
148 				 _TIF_NEED_RESCHED_LAZY | _TIF_NOTIFY_RESUME | \
149 				 _TIF_UPROBE | _TIF_RESTORE_TM | \
150 				 _TIF_PATCH_PENDING | _TIF_NOTIFY_SIGNAL)
151 
152 #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
153 
154 /* Bits in local_flags */
155 /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
156 #define TLF_NAPPING		0	/* idle thread enabled NAP mode */
157 #define TLF_SLEEPING		1	/* suspend code enabled SLEEP mode */
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_RUNLATCH		(1 << TLF_RUNLATCH)
163 
164 #ifndef __ASSEMBLER__
165 
166 static inline void clear_thread_local_flags(unsigned int flags)
167 {
168 	struct thread_info *ti = current_thread_info();
169 	ti->local_flags &= ~flags;
170 }
171 
172 static inline bool test_thread_local_flags(unsigned int flags)
173 {
174 	struct thread_info *ti = current_thread_info();
175 	return (ti->local_flags & flags) != 0;
176 }
177 
178 #ifdef CONFIG_COMPAT
179 #define is_32bit_task()	(test_thread_flag(TIF_32BIT))
180 #define is_tsk_32bit_task(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT))
181 #define clear_tsk_compat_task(tsk) (clear_tsk_thread_flag(p, TIF_32BIT))
182 #else
183 #define is_32bit_task()	(IS_ENABLED(CONFIG_PPC32))
184 #define is_tsk_32bit_task(tsk)	(IS_ENABLED(CONFIG_PPC32))
185 #define clear_tsk_compat_task(tsk) do { } while (0)
186 #endif
187 
188 #if defined(CONFIG_PPC64)
189 #define is_elf2_task() (test_thread_flag(TIF_ELF2ABI))
190 #else
191 #define is_elf2_task() (0)
192 #endif
193 
194 /*
195  * Walks up the stack frames to make sure that the specified object is
196  * entirely contained by a single stack frame.
197  *
198  * Returns:
199  *	GOOD_FRAME	if within a frame
200  *	BAD_STACK	if placed across a frame boundary (or outside stack)
201  */
202 static inline int arch_within_stack_frames(const void * const stack,
203 					   const void * const stackend,
204 					   const void *obj, unsigned long len)
205 {
206 	const void *params;
207 	const void *frame;
208 
209 	params = *(const void * const *)current_stack_pointer + STACK_FRAME_PARAMS;
210 	frame = **(const void * const * const *)current_stack_pointer;
211 
212 	/*
213 	 * low -----------------------------------------------------------> high
214 	 * [backchain][metadata][params][local vars][saved registers][backchain]
215 	 *                      ^------------------------------------^
216 	 *                      |  allows copies only in this region |
217 	 *                      |                                    |
218 	 *                    params                               frame
219 	 * The metadata region contains the saved LR, CR etc.
220 	 */
221 	while (stack <= frame && frame < stackend) {
222 		if (obj + len <= frame)
223 			return obj >= params ? GOOD_FRAME : BAD_STACK;
224 		params = frame + STACK_FRAME_PARAMS;
225 		frame = *(const void * const *)frame;
226 	}
227 
228 	return BAD_STACK;
229 }
230 
231 #ifdef CONFIG_PPC32
232 extern void *emergency_ctx[];
233 #endif
234 
235 #endif	/* !__ASSEMBLER__ */
236 
237 #endif /* __KERNEL__ */
238 
239 #endif /* _ASM_POWERPC_THREAD_INFO_H */
240