Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
s390/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>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-12-13a4669dfc8c@linutronix.de
authored by
Thomas Weißschuh
and committed by
Thomas Gleixner
9bf39a65
31e9fa2b
+17
-153
+1
arch/s390/Kconfig
+1
arch/s390/Kconfig
+1
-3
arch/s390/include/asm/vdso.h
+1
-3
arch/s390/include/asm/vdso.h
-12
arch/s390/include/asm/vdso/getrandom.h
-12
arch/s390/include/asm/vdso/getrandom.h
···
23
23
return syscall3(__NR_getrandom, (long)buffer, (long)len, (long)flags);
24
24
}
25
25
26
-
static __always_inline const struct vdso_rng_data *__arch_get_vdso_rng_data(void)
27
-
{
28
-
/*
29
-
* The RNG data is in the real VVAR data page, but if a task belongs to a time namespace
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-
* then VVAR_DATA_PAGE_OFFSET points to the namespace-specific VVAR page and VVAR_TIMENS_
31
-
* PAGE_OFFSET points to the real VVAR page.
32
-
*/
33
-
if (IS_ENABLED(CONFIG_TIME_NS) && _vdso_data->clock_mode == VDSO_CLOCKMODE_TIMENS)
34
-
return (void *)&_vdso_rng_data + VVAR_TIMENS_PAGE_OFFSET * PAGE_SIZE;
35
-
return &_vdso_rng_data;
36
-
}
37
-
38
26
#endif /* !__ASSEMBLY__ */
39
27
40
28
#endif /* __ASM_VDSO_GETRANDOM_H */
+1
-14
arch/s390/include/asm/vdso/gettimeofday.h
+1
-14
arch/s390/include/asm/vdso/gettimeofday.h
···
14
14
#include <linux/compiler.h>
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-
static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
18
-
{
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-
return _vdso_data;
20
-
}
21
-
22
-
static inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_data *vd)
17
+
static inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_time_data *vd)
23
18
{
24
19
u64 adj, now;
25
20
···
43
48
{
44
49
return syscall2(__NR_clock_getres, (long)clkid, (long)ts);
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50
}
46
-
47
-
#ifdef CONFIG_TIME_NS
48
-
static __always_inline
49
-
const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
50
-
{
51
-
return _timens_data;
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-
}
53
-
#endif
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51
55
52
#endif
-20
arch/s390/include/asm/vdso/vsyscall.h
-20
arch/s390/include/asm/vdso/vsyscall.h
···
2
2
#ifndef __ASM_VDSO_VSYSCALL_H
3
3
#define __ASM_VDSO_VSYSCALL_H
4
4
5
-
#define __VDSO_RND_DATA_OFFSET 768
6
-
7
5
#ifndef __ASSEMBLY__
8
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#include <linux/hrtimer.h>
10
8
#include <vdso/datapage.h>
11
9
#include <asm/vdso.h>
12
-
13
-
enum vvar_pages {
14
-
VVAR_DATA_PAGE_OFFSET,
15
-
VVAR_TIMENS_PAGE_OFFSET,
16
-
VVAR_NR_PAGES
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-
};
18
-
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-
static __always_inline struct vdso_data *__s390_get_k_vdso_data(void)
20
-
{
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-
return vdso_data;
22
-
}
23
-
#define __arch_get_k_vdso_data __s390_get_k_vdso_data
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-
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-
static __always_inline struct vdso_rng_data *__s390_get_k_vdso_rnd_data(void)
26
-
{
27
-
return (void *)vdso_data + __VDSO_RND_DATA_OFFSET;
28
-
}
29
-
#define __arch_get_k_vdso_rng_data __s390_get_k_vdso_rnd_data
30
10
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11
/* The asm-generic header needs to be included after the definitions above */
32
12
#include <asm-generic/vdso/vsyscall.h>
+3
-3
arch/s390/kernel/time.c
+3
-3
arch/s390/kernel/time.c
···
84
84
/* Initialize TOD steering parameters */
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tod_steering_end = tod_clock_base.tod;
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for (cs = 0; cs < CS_BASES; cs++)
87
-
vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
87
+
vdso_k_time_data[cs].arch_data.tod_steering_end = tod_steering_end;
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if (!test_facility(28))
90
90
return;
···
390
390
tod_steering_delta);
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tod_steering_end = now + (abs(tod_steering_delta) << 15);
392
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for (cs = 0; cs < CS_BASES; cs++) {
393
-
vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
394
-
vdso_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
393
+
vdso_k_time_data[cs].arch_data.tod_steering_end = tod_steering_end;
394
+
vdso_k_time_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
395
395
}
396
396
397
397
/* Update LPAR offset. */
+5
-92
arch/s390/kernel/vdso.c
+5
-92
arch/s390/kernel/vdso.c
···
16
16
#include <linux/mm.h>
17
17
#include <linux/slab.h>
18
18
#include <linux/smp.h>
19
-
#include <linux/time_namespace.h>
20
19
#include <linux/random.h>
20
+
#include <linux/vdso_datastore.h>
21
21
#include <vdso/datapage.h>
22
22
#include <asm/vdso/vsyscall.h>
23
23
#include <asm/alternative.h>
···
26
26
extern char vdso64_start[], vdso64_end[];
27
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extern char vdso32_start[], vdso32_end[];
28
28
29
-
static struct vm_special_mapping vvar_mapping;
30
-
31
-
static union vdso_data_store vdso_data_store __page_aligned_data;
32
-
33
-
struct vdso_data *vdso_data = vdso_data_store.data;
34
-
35
-
#ifdef CONFIG_TIME_NS
36
-
struct vdso_data *arch_get_vdso_data(void *vvar_page)
37
-
{
38
-
return (struct vdso_data *)(vvar_page);
39
-
}
40
-
41
-
/*
42
-
* The VVAR page layout depends on whether a task belongs to the root or
43
-
* non-root time namespace. Whenever a task changes its namespace, the VVAR
44
-
* page tables are cleared and then they will be re-faulted with a
45
-
* corresponding layout.
46
-
* See also the comment near timens_setup_vdso_data() for details.
47
-
*/
48
-
int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
49
-
{
50
-
struct mm_struct *mm = task->mm;
51
-
VMA_ITERATOR(vmi, mm, 0);
52
-
struct vm_area_struct *vma;
53
-
54
-
mmap_read_lock(mm);
55
-
for_each_vma(vmi, vma) {
56
-
if (!vma_is_special_mapping(vma, &vvar_mapping))
57
-
continue;
58
-
zap_vma_pages(vma);
59
-
break;
60
-
}
61
-
mmap_read_unlock(mm);
62
-
return 0;
63
-
}
64
-
#endif
65
-
66
-
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
67
-
struct vm_area_struct *vma, struct vm_fault *vmf)
68
-
{
69
-
struct page *timens_page = find_timens_vvar_page(vma);
70
-
unsigned long addr, pfn;
71
-
vm_fault_t err;
72
-
73
-
switch (vmf->pgoff) {
74
-
case VVAR_DATA_PAGE_OFFSET:
75
-
pfn = virt_to_pfn(vdso_data);
76
-
if (timens_page) {
77
-
/*
78
-
* Fault in VVAR page too, since it will be accessed
79
-
* to get clock data anyway.
80
-
*/
81
-
addr = vmf->address + VVAR_TIMENS_PAGE_OFFSET * PAGE_SIZE;
82
-
err = vmf_insert_pfn(vma, addr, pfn);
83
-
if (unlikely(err & VM_FAULT_ERROR))
84
-
return err;
85
-
pfn = page_to_pfn(timens_page);
86
-
}
87
-
break;
88
-
#ifdef CONFIG_TIME_NS
89
-
case VVAR_TIMENS_PAGE_OFFSET:
90
-
/*
91
-
* If a task belongs to a time namespace then a namespace
92
-
* specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
93
-
* the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
94
-
* offset.
95
-
* See also the comment near timens_setup_vdso_data().
96
-
*/
97
-
if (!timens_page)
98
-
return VM_FAULT_SIGBUS;
99
-
pfn = virt_to_pfn(vdso_data);
100
-
break;
101
-
#endif /* CONFIG_TIME_NS */
102
-
default:
103
-
return VM_FAULT_SIGBUS;
104
-
}
105
-
return vmf_insert_pfn(vma, vmf->address, pfn);
106
-
}
107
-
108
29
static int vdso_mremap(const struct vm_special_mapping *sm,
109
30
struct vm_area_struct *vma)
110
31
{
111
32
current->mm->context.vdso_base = vma->vm_start;
112
33
return 0;
113
34
}
114
-
115
-
static struct vm_special_mapping vvar_mapping = {
116
-
.name = "[vvar]",
117
-
.fault = vvar_fault,
118
-
};
119
35
120
36
static struct vm_special_mapping vdso64_mapping = {
121
37
.name = "[vdso]",
···
58
142
struct vm_area_struct *vma;
59
143
int rc;
60
144
61
-
BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
145
+
BUILD_BUG_ON(VDSO_NR_PAGES != __VDSO_PAGES);
62
146
if (mmap_write_lock_killable(mm))
63
147
return -EINTR;
64
148
···
73
157
rc = vvar_start;
74
158
if (IS_ERR_VALUE(vvar_start))
75
159
goto out;
76
-
vma = _install_special_mapping(mm, vvar_start, VVAR_NR_PAGES*PAGE_SIZE,
77
-
VM_READ|VM_MAYREAD|VM_IO|VM_DONTDUMP|
78
-
VM_PFNMAP,
79
-
&vvar_mapping);
160
+
vma = vdso_install_vvar_mapping(mm, vvar_start);
80
161
rc = PTR_ERR(vma);
81
162
if (IS_ERR(vma))
82
163
goto out;
83
-
vdso_text_start = vvar_start + VVAR_NR_PAGES * PAGE_SIZE;
164
+
vdso_text_start = vvar_start + VDSO_NR_PAGES * PAGE_SIZE;
84
165
/* VM_MAYWRITE for COW so gdb can set breakpoints */
85
166
vma = _install_special_mapping(mm, vdso_text_start, vdso_text_len,
86
167
VM_READ|VM_EXEC|
···
133
220
134
221
unsigned long vdso_size(void)
135
222
{
136
-
return vdso_text_size() + VVAR_NR_PAGES * PAGE_SIZE;
223
+
return vdso_text_size() + VDSO_NR_PAGES * PAGE_SIZE;
137
224
}
138
225
139
226
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+3
-4
arch/s390/kernel/vdso32/vdso32.lds.S
+3
-4
arch/s390/kernel/vdso32/vdso32.lds.S
···
6
6
7
7
#include <asm/page.h>
8
8
#include <asm/vdso.h>
9
+
#include <vdso/datapage.h>
9
10
10
11
OUTPUT_FORMAT("elf32-s390", "elf32-s390", "elf32-s390")
11
12
OUTPUT_ARCH(s390:31-bit)
12
13
13
14
SECTIONS
14
15
{
15
-
PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
16
-
#ifdef CONFIG_TIME_NS
17
-
PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
18
-
#endif
16
+
VDSO_VVAR_SYMS
17
+
19
18
. = SIZEOF_HEADERS;
20
19
21
20
.hash : { *(.hash) } :text
+3
-5
arch/s390/kernel/vdso64/vdso64.lds.S
+3
-5
arch/s390/kernel/vdso64/vdso64.lds.S
···
7
7
#include <asm/vdso/vsyscall.h>
8
8
#include <asm/page.h>
9
9
#include <asm/vdso.h>
10
+
#include <vdso/datapage.h>
10
11
11
12
OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
12
13
OUTPUT_ARCH(s390:64-bit)
13
14
14
15
SECTIONS
15
16
{
16
-
PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
17
-
PROVIDE(_vdso_rng_data = _vdso_data + __VDSO_RND_DATA_OFFSET);
18
-
#ifdef CONFIG_TIME_NS
19
-
PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
20
-
#endif
17
+
VDSO_VVAR_SYMS
18
+
21
19
. = SIZEOF_HEADERS;
22
20
23
21
.hash : { *(.hash) } :text