1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PAGE_64_H
#define _ASM_X86_PAGE_64_H
#include <asm/page_64_types.h>
#ifndef __ASSEMBLY__
#include <asm/cpufeatures.h>
#include <asm/alternative.h>
#include <linux/kmsan-checks.h>
/* duplicated to the one in bootmem.h */
extern unsigned long max_pfn;
extern unsigned long phys_base;
extern unsigned long page_offset_base;
extern unsigned long vmalloc_base;
extern unsigned long vmemmap_base;
extern unsigned long physmem_end;
static __always_inline unsigned long __phys_addr_nodebug(unsigned long x)
{
unsigned long y = x - __START_KERNEL_map;
/* use the carry flag to determine if x was < __START_KERNEL_map */
x = y + ((x > y) ? phys_base : (__START_KERNEL_map - PAGE_OFFSET));
return x;
}
#ifdef CONFIG_DEBUG_VIRTUAL
extern unsigned long __phys_addr(unsigned long);
extern unsigned long __phys_addr_symbol(unsigned long);
#else
#define __phys_addr(x) __phys_addr_nodebug(x)
#define __phys_addr_symbol(x) \
((unsigned long)(x) - __START_KERNEL_map + phys_base)
#endif
#define __phys_reloc_hide(x) (x)
void clear_page_orig(void *page);
void clear_page_rep(void *page);
void clear_page_erms(void *page);
static inline void clear_page(void *page)
{
/*
* Clean up KMSAN metadata for the page being cleared. The assembly call
* below clobbers @page, so we perform unpoisoning before it.
*/
kmsan_unpoison_memory(page, PAGE_SIZE);
alternative_call_2(clear_page_orig,
clear_page_rep, X86_FEATURE_REP_GOOD,
clear_page_erms, X86_FEATURE_ERMS,
"=D" (page),
"D" (page)
: "cc", "memory", "rax", "rcx");
}
void copy_page(void *to, void *from);
#ifdef CONFIG_X86_5LEVEL
/*
* User space process size. This is the first address outside the user range.
* There are a few constraints that determine this:
*
* On Intel CPUs, if a SYSCALL instruction is at the highest canonical
* address, then that syscall will enter the kernel with a
* non-canonical return address, and SYSRET will explode dangerously.
* We avoid this particular problem by preventing anything
* from being mapped at the maximum canonical address.
*
* On AMD CPUs in the Ryzen family, there's a nasty bug in which the
* CPUs malfunction if they execute code from the highest canonical page.
* They'll speculate right off the end of the canonical space, and
* bad things happen. This is worked around in the same way as the
* Intel problem.
*
* With page table isolation enabled, we map the LDT in ... [stay tuned]
*/
static __always_inline unsigned long task_size_max(void)
{
unsigned long ret;
alternative_io("movq %[small],%0","movq %[large],%0",
X86_FEATURE_LA57,
"=r" (ret),
[small] "i" ((1ul << 47)-PAGE_SIZE),
[large] "i" ((1ul << 56)-PAGE_SIZE));
return ret;
}
#endif /* CONFIG_X86_5LEVEL */
#endif /* !__ASSEMBLY__ */
#ifdef CONFIG_X86_VSYSCALL_EMULATION
# define __HAVE_ARCH_GATE_AREA 1
#endif
#endif /* _ASM_X86_PAGE_64_H */
|
