Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
4 * Copyright (C) 2012 Regents of the University of California
5 * Copyright (C) 2017 SiFive
6 */
7
8#ifndef _ASM_RISCV_THREAD_INFO_H
9#define _ASM_RISCV_THREAD_INFO_H
10
11#include <asm/page.h>
12#include <linux/const.h>
13
14#ifdef CONFIG_KASAN
15#define KASAN_STACK_ORDER 1
16#else
17#define KASAN_STACK_ORDER 0
18#endif
19
20/* thread information allocation */
21#ifdef CONFIG_64BIT
22#define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER)
23#else
24#define THREAD_SIZE_ORDER (1 + KASAN_STACK_ORDER)
25#endif
26#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
27
28/*
29 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
30 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
31 * assembly.
32 */
33#ifdef CONFIG_VMAP_STACK
34#define THREAD_ALIGN (2 * THREAD_SIZE)
35#else
36#define THREAD_ALIGN THREAD_SIZE
37#endif
38
39#define THREAD_SHIFT (PAGE_SHIFT + THREAD_SIZE_ORDER)
40#define OVERFLOW_STACK_SIZE SZ_4K
41#define SHADOW_OVERFLOW_STACK_SIZE (1024)
42
43#ifndef __ASSEMBLY__
44
45extern long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE / sizeof(long)];
46extern unsigned long spin_shadow_stack;
47
48#include <asm/processor.h>
49#include <asm/csr.h>
50
51/*
52 * low level task data that entry.S needs immediate access to
53 * - this struct should fit entirely inside of one cache line
54 * - if the members of this struct changes, the assembly constants
55 * in asm-offsets.c must be updated accordingly
56 * - thread_info is included in task_struct at an offset of 0. This means that
57 * tp points to both thread_info and task_struct.
58 */
59struct thread_info {
60 unsigned long flags; /* low level flags */
61 int preempt_count; /* 0=>preemptible, <0=>BUG */
62 /*
63 * These stack pointers are overwritten on every system call or
64 * exception. SP is also saved to the stack it can be recovered when
65 * overwritten.
66 */
67 long kernel_sp; /* Kernel stack pointer */
68 long user_sp; /* User stack pointer */
69 int cpu;
70 unsigned long syscall_work; /* SYSCALL_WORK_ flags */
71};
72
73/*
74 * macros/functions for gaining access to the thread information structure
75 *
76 * preempt_count needs to be 1 initially, until the scheduler is functional.
77 */
78#define INIT_THREAD_INFO(tsk) \
79{ \
80 .flags = 0, \
81 .preempt_count = INIT_PREEMPT_COUNT, \
82}
83
84#endif /* !__ASSEMBLY__ */
85
86/*
87 * thread information flags
88 * - these are process state flags that various assembly files may need to
89 * access
90 * - pending work-to-be-done flags are in lowest half-word
91 * - other flags in upper half-word(s)
92 */
93#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
94#define TIF_SIGPENDING 2 /* signal pending */
95#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
96#define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */
97#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
98#define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */
99#define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */
100#define TIF_32BIT 11 /* compat-mode 32bit process */
101
102#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
103#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
104#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
105#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL)
106#define _TIF_UPROBE (1 << TIF_UPROBE)
107
108#define _TIF_WORK_MASK \
109 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
110 _TIF_NOTIFY_SIGNAL | _TIF_UPROBE)
111
112#endif /* _ASM_RISCV_THREAD_INFO_H */