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kernel
os
linux
riscv: vdso: Switch to generic storage implementation
The generic storage implementation provides the same features as the
custom one. However it can be shared between architectures, making
maintenance easier.
Co-developed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-9-13a4669dfc8c@linutronix.de
authored by
Thomas Weißschuh
and committed by
Thomas Gleixner
46fe55b2
0b3bc335
+18
-124
+2
-1
arch/riscv/Kconfig
+2
-1
arch/riscv/Kconfig
···
53
53
select ARCH_HAS_SYSCALL_WRAPPER
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select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
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select ARCH_HAS_UBSAN
56
-
select ARCH_HAS_VDSO_TIME_DATA
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+
select ARCH_HAS_VDSO_ARCH_DATA if GENERIC_VDSO_DATA_STORE
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select ARCH_KEEP_MEMBLOCK if ACPI
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select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU
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select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
···
116
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select GENERIC_SCHED_CLOCK
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select GENERIC_SMP_IDLE_THREAD
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select GENERIC_TIME_VSYSCALL if MMU && 64BIT
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+
select GENERIC_VDSO_DATA_STORE if MMU
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select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
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select HARDIRQS_SW_RESEND
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select HAS_IOPORT if MMU
+1
-1
arch/riscv/include/asm/vdso.h
+1
-1
arch/riscv/include/asm/vdso.h
+1
-13
arch/riscv/include/asm/vdso/gettimeofday.h
+1
-13
arch/riscv/include/asm/vdso/gettimeofday.h
···
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#endif /* CONFIG_GENERIC_TIME_VSYSCALL */
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static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
72
-
const struct vdso_data *vd)
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+
const struct vdso_time_data *vd)
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{
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/*
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* The purpose of csr_read(CSR_TIME) is to trap the system into
···
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return csr_read(CSR_TIME);
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}
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-
static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
83
-
{
84
-
return _vdso_data;
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-
}
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-
87
-
#ifdef CONFIG_TIME_NS
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-
static __always_inline
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-
const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
90
-
{
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-
return _timens_data;
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-
}
93
-
#endif
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82
#endif /* !__ASSEMBLY__ */
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#endif /* __ASM_VDSO_GETTIMEOFDAY_H */
+4
-4
arch/riscv/include/asm/vdso/time_data.h
arch/riscv/include/asm/vdso/arch_data.h
+4
-4
arch/riscv/include/asm/vdso/time_data.h
arch/riscv/include/asm/vdso/arch_data.h
···
1
1
/* SPDX-License-Identifier: GPL-2.0 */
2
-
#ifndef __RISCV_ASM_VDSO_TIME_DATA_H
3
-
#define __RISCV_ASM_VDSO_TIME_DATA_H
2
+
#ifndef __RISCV_ASM_VDSO_ARCH_DATA_H
3
+
#define __RISCV_ASM_VDSO_ARCH_DATA_H
4
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5
#include <linux/types.h>
6
6
#include <vdso/datapage.h>
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#include <asm/hwprobe.h>
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9
-
struct arch_vdso_time_data {
9
+
struct vdso_arch_data {
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/* Stash static answers to the hwprobe queries when all CPUs are selected. */
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__u64 all_cpu_hwprobe_values[RISCV_HWPROBE_MAX_KEY + 1];
12
12
···
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__u8 homogeneous_cpus;
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};
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17
-
#endif /* __RISCV_ASM_VDSO_TIME_DATA_H */
17
+
#endif /* __RISCV_ASM_VDSO_ARCH_DATA_H */
-9
arch/riscv/include/asm/vdso/vsyscall.h
-9
arch/riscv/include/asm/vdso/vsyscall.h
···
6
6
7
7
#include <vdso/datapage.h>
8
8
9
-
extern struct vdso_data *vdso_data;
10
-
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static __always_inline struct vdso_data *__riscv_get_k_vdso_data(void)
12
-
{
13
-
return vdso_data;
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-
}
15
-
16
-
#define __arch_get_k_vdso_data __riscv_get_k_vdso_data
17
-
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/* The asm-generic header needs to be included after the definitions above */
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#include <asm-generic/vdso/vsyscall.h>
20
11
+1
-2
arch/riscv/kernel/sys_hwprobe.c
+1
-2
arch/riscv/kernel/sys_hwprobe.c
···
450
450
451
451
static int __init init_hwprobe_vdso_data(void)
452
452
{
453
-
struct vdso_data *vd = __arch_get_k_vdso_data();
454
-
struct arch_vdso_time_data *avd = &vd->arch_data;
453
+
struct vdso_arch_data *avd = vdso_k_arch_data;
455
454
u64 id_bitsmash = 0;
456
455
struct riscv_hwprobe pair;
457
456
int key;
+4
-86
arch/riscv/kernel/vdso.c
+4
-86
arch/riscv/kernel/vdso.c
···
13
13
#include <linux/err.h>
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14
#include <asm/page.h>
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#include <asm/vdso.h>
16
-
#include <linux/time_namespace.h>
16
+
#include <linux/vdso_datastore.h>
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#include <vdso/datapage.h>
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#include <vdso/vsyscall.h>
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20
-
enum vvar_pages {
21
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VVAR_DATA_PAGE_OFFSET,
22
-
VVAR_TIMENS_PAGE_OFFSET,
23
-
VVAR_NR_PAGES,
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-
};
25
-
26
-
#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
27
-
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-
static union vdso_data_store vdso_data_store __page_aligned_data;
29
-
struct vdso_data *vdso_data = vdso_data_store.data;
20
+
#define VVAR_SIZE (VDSO_NR_PAGES << PAGE_SHIFT)
30
21
31
22
struct __vdso_info {
32
23
const char *name;
···
70
79
vdso_info->cm->pages = vdso_pagelist;
71
80
}
72
81
73
-
#ifdef CONFIG_TIME_NS
74
-
struct vdso_data *arch_get_vdso_data(void *vvar_page)
75
-
{
76
-
return (struct vdso_data *)(vvar_page);
77
-
}
78
-
79
-
static const struct vm_special_mapping rv_vvar_map;
80
-
81
-
/*
82
-
* The vvar mapping contains data for a specific time namespace, so when a task
83
-
* changes namespace we must unmap its vvar data for the old namespace.
84
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* Subsequent faults will map in data for the new namespace.
85
-
*
86
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* For more details see timens_setup_vdso_data().
87
-
*/
88
-
int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
89
-
{
90
-
struct mm_struct *mm = task->mm;
91
-
struct vm_area_struct *vma;
92
-
VMA_ITERATOR(vmi, mm, 0);
93
-
94
-
mmap_read_lock(mm);
95
-
96
-
for_each_vma(vmi, vma) {
97
-
if (vma_is_special_mapping(vma, &rv_vvar_map))
98
-
zap_vma_pages(vma);
99
-
}
100
-
101
-
mmap_read_unlock(mm);
102
-
return 0;
103
-
}
104
-
#endif
105
-
106
-
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
107
-
struct vm_area_struct *vma, struct vm_fault *vmf)
108
-
{
109
-
struct page *timens_page = find_timens_vvar_page(vma);
110
-
unsigned long pfn;
111
-
112
-
switch (vmf->pgoff) {
113
-
case VVAR_DATA_PAGE_OFFSET:
114
-
if (timens_page)
115
-
pfn = page_to_pfn(timens_page);
116
-
else
117
-
pfn = sym_to_pfn(vdso_data);
118
-
break;
119
-
#ifdef CONFIG_TIME_NS
120
-
case VVAR_TIMENS_PAGE_OFFSET:
121
-
/*
122
-
* If a task belongs to a time namespace then a namespace
123
-
* specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
124
-
* the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
125
-
* offset.
126
-
* See also the comment near timens_setup_vdso_data().
127
-
*/
128
-
if (!timens_page)
129
-
return VM_FAULT_SIGBUS;
130
-
pfn = sym_to_pfn(vdso_data);
131
-
break;
132
-
#endif /* CONFIG_TIME_NS */
133
-
default:
134
-
return VM_FAULT_SIGBUS;
135
-
}
136
-
137
-
return vmf_insert_pfn(vma, vmf->address, pfn);
138
-
}
139
-
140
-
static const struct vm_special_mapping rv_vvar_map = {
141
-
.name = "[vvar]",
142
-
.fault = vvar_fault,
143
-
};
144
-
145
82
static struct vm_special_mapping rv_vdso_map __ro_after_init = {
146
83
.name = "[vdso]",
147
84
.mremap = vdso_mremap,
···
115
196
unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
116
197
void *ret;
117
198
118
-
BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
199
+
BUILD_BUG_ON(VDSO_NR_PAGES != __VDSO_PAGES);
119
200
120
201
vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
121
202
/* Be sure to map the data page */
···
127
208
goto up_fail;
128
209
}
129
210
130
-
ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
131
-
(VM_READ | VM_MAYREAD | VM_PFNMAP), &rv_vvar_map);
211
+
ret = vdso_install_vvar_mapping(mm, vdso_base);
132
212
if (IS_ERR(ret))
133
213
goto up_fail;
134
214
+2
-4
arch/riscv/kernel/vdso/hwprobe.c
+2
-4
arch/riscv/kernel/vdso/hwprobe.c
···
16
16
size_t cpusetsize, unsigned long *cpus,
17
17
unsigned int flags)
18
18
{
19
-
const struct vdso_data *vd = __arch_get_vdso_data();
20
-
const struct arch_vdso_time_data *avd = &vd->arch_data;
19
+
const struct vdso_arch_data *avd = &vdso_u_arch_data;
21
20
bool all_cpus = !cpusetsize && !cpus;
22
21
struct riscv_hwprobe *p = pairs;
23
22
struct riscv_hwprobe *end = pairs + pair_count;
···
50
51
size_t cpusetsize, unsigned long *cpus,
51
52
unsigned int flags)
52
53
{
53
-
const struct vdso_data *vd = __arch_get_vdso_data();
54
-
const struct arch_vdso_time_data *avd = &vd->arch_data;
54
+
const struct vdso_arch_data *avd = &vdso_u_arch_data;
55
55
struct riscv_hwprobe *p = pairs;
56
56
struct riscv_hwprobe *end = pairs + pair_count;
57
57
unsigned char *c = (unsigned char *)cpus;
+3
-4
arch/riscv/kernel/vdso/vdso.lds.S
+3
-4
arch/riscv/kernel/vdso/vdso.lds.S
···
4
4
*/
5
5
#include <asm/page.h>
6
6
#include <asm/vdso.h>
7
+
#include <vdso/datapage.h>
7
8
8
9
OUTPUT_ARCH(riscv)
9
10
10
11
SECTIONS
11
12
{
12
-
PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
13
-
#ifdef CONFIG_TIME_NS
14
-
PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
15
-
#endif
13
+
VDSO_VVAR_SYMS
14
+
16
15
. = SIZEOF_HEADERS;
17
16
18
17
.hash : { *(.hash) } :text