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 __ASSEMBLY__
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	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 */
87 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
88 
89 void arch_setup_new_exec(void);
90 #define arch_setup_new_exec arch_setup_new_exec
91 
92 #endif /* __ASSEMBLY__ */
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_SECCOMP		10	/* secure computing */
107 #define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */
108 #define TIF_NOERROR		12	/* Force successful syscall return */
109 #define TIF_NOTIFY_RESUME	13	/* callback before returning to user */
110 #define TIF_UPROBE		14	/* breakpointed or single-stepping */
111 #define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */
112 #define TIF_EMULATE_STACK_STORE	16	/* Is an instruction emulation
113 						for stack store? */
114 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
115 #if defined(CONFIG_PPC64)
116 #define TIF_ELF2ABI		18	/* function descriptors must die! */
117 #endif
118 #define TIF_POLLING_NRFLAG	19	/* true if poll_idle() is polling TIF_NEED_RESCHED */
119 #define TIF_32BIT		20	/* 32 bit binary */
120 
121 /* as above, but as bit values */
122 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
123 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
124 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
125 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
126 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
127 #define _TIF_32BIT		(1<<TIF_32BIT)
128 #define _TIF_RESTORE_TM		(1<<TIF_RESTORE_TM)
129 #define _TIF_PATCH_PENDING	(1<<TIF_PATCH_PENDING)
130 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
131 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
132 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
133 #define _TIF_RESTOREALL		(1<<TIF_RESTOREALL)
134 #define _TIF_NOERROR		(1<<TIF_NOERROR)
135 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
136 #define _TIF_UPROBE		(1<<TIF_UPROBE)
137 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
138 #define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
139 #define _TIF_SYSCALL_EMU	(1<<TIF_SYSCALL_EMU)
140 #define _TIF_SYSCALL_DOTRACE	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
141 				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
142 				 _TIF_SYSCALL_EMU)
143 
144 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
145 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
146 				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
147 				 _TIF_NOTIFY_SIGNAL)
148 #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
149 
150 /* Bits in local_flags */
151 /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
152 #define TLF_NAPPING		0	/* idle thread enabled NAP mode */
153 #define TLF_SLEEPING		1	/* suspend code enabled SLEEP mode */
154 #define TLF_LAZY_MMU		3	/* tlb_batch is active */
155 #define TLF_RUNLATCH		4	/* Is the runlatch enabled? */
156 
157 #define _TLF_NAPPING		(1 << TLF_NAPPING)
158 #define _TLF_SLEEPING		(1 << TLF_SLEEPING)
159 #define _TLF_LAZY_MMU		(1 << TLF_LAZY_MMU)
160 #define _TLF_RUNLATCH		(1 << TLF_RUNLATCH)
161 
162 #ifndef __ASSEMBLY__
163 
clear_thread_local_flags(unsigned int flags)164 static inline void clear_thread_local_flags(unsigned int flags)
165 {
166 	struct thread_info *ti = current_thread_info();
167 	ti->local_flags &= ~flags;
168 }
169 
test_thread_local_flags(unsigned int flags)170 static inline bool test_thread_local_flags(unsigned int flags)
171 {
172 	struct thread_info *ti = current_thread_info();
173 	return (ti->local_flags & flags) != 0;
174 }
175 
176 #ifdef CONFIG_COMPAT
177 #define is_32bit_task()	(test_thread_flag(TIF_32BIT))
178 #define is_tsk_32bit_task(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT))
179 #define clear_tsk_compat_task(tsk) (clear_tsk_thread_flag(p, TIF_32BIT))
180 #else
181 #define is_32bit_task()	(IS_ENABLED(CONFIG_PPC32))
182 #define is_tsk_32bit_task(tsk)	(IS_ENABLED(CONFIG_PPC32))
183 #define clear_tsk_compat_task(tsk) do { } while (0)
184 #endif
185 
186 #if defined(CONFIG_PPC64)
187 #define is_elf2_task() (test_thread_flag(TIF_ELF2ABI))
188 #else
189 #define is_elf2_task() (0)
190 #endif
191 
192 /*
193  * Walks up the stack frames to make sure that the specified object is
194  * entirely contained by a single stack frame.
195  *
196  * Returns:
197  *	GOOD_FRAME	if within a frame
198  *	BAD_STACK	if placed across a frame boundary (or outside stack)
199  */
arch_within_stack_frames(const void * const stack,const void * const stackend,const void * obj,unsigned long len)200 static inline int arch_within_stack_frames(const void * const stack,
201 					   const void * const stackend,
202 					   const void *obj, unsigned long len)
203 {
204 	const void *params;
205 	const void *frame;
206 
207 	params = *(const void * const *)current_stack_pointer + STACK_FRAME_PARAMS;
208 	frame = **(const void * const * const *)current_stack_pointer;
209 
210 	/*
211 	 * low -----------------------------------------------------------> high
212 	 * [backchain][metadata][params][local vars][saved registers][backchain]
213 	 *                      ^------------------------------------^
214 	 *                      |  allows copies only in this region |
215 	 *                      |                                    |
216 	 *                    params                               frame
217 	 * The metadata region contains the saved LR, CR etc.
218 	 */
219 	while (stack <= frame && frame < stackend) {
220 		if (obj + len <= frame)
221 			return obj >= params ? GOOD_FRAME : BAD_STACK;
222 		params = frame + STACK_FRAME_PARAMS;
223 		frame = *(const void * const *)frame;
224 	}
225 
226 	return BAD_STACK;
227 }
228 
229 #endif	/* !__ASSEMBLY__ */
230 
231 #endif /* __KERNEL__ */
232 
233 #endif /* _ASM_POWERPC_THREAD_INFO_H */
234