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s390/vdso: Switch to generic storage implementation

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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
This commit is contained in:
Thomas Weißschuh
2025-02-04 13:05:44 +01:00
committed by Thomas Gleixner
parent 31e9fa2ba9
commit 9bf39a65b2
9 changed files with 17 additions and 153 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/s390/Kconfig
+1
View File
@@ -166,6 +166,7 @@ config S390
select GENERIC_PTDUMP
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL
select GENERIC_VDSO_DATA_STORE
select GENERIC_VDSO_TIME_NS
select GENERIC_IOREMAP if PCI
select HAVE_ALIGNED_STRUCT_PAGE
arch/s390/include/asm/vdso.h
+1 -3
View File
@@ -6,13 +6,11 @@
#ifndef __ASSEMBLY__
extern struct vdso_data *vdso_data;
int vdso_getcpu_init(void);
#endif /* __ASSEMBLY__ */
#define __VVAR_PAGES 2
#define __VDSO_PAGES 4
#define VDSO_VERSION_STRING LINUX_2.6.29
arch/s390/include/asm/vdso/getrandom.h
-12
View File
@@ -23,18 +23,6 @@ static __always_inline ssize_t getrandom_syscall(void *buffer, size_t len, unsig
return syscall3(__NR_getrandom, (long)buffer, (long)len, (long)flags);
}
static __always_inline const struct vdso_rng_data *__arch_get_vdso_rng_data(void)
{
/*
* The RNG data is in the real VVAR data page, but if a task belongs to a time namespace
* then VVAR_DATA_PAGE_OFFSET points to the namespace-specific VVAR page and VVAR_TIMENS_
* PAGE_OFFSET points to the real VVAR page.
*/
if (IS_ENABLED(CONFIG_TIME_NS) && _vdso_data->clock_mode == VDSO_CLOCKMODE_TIMENS)
return (void *)&_vdso_rng_data + VVAR_TIMENS_PAGE_OFFSET * PAGE_SIZE;
return &_vdso_rng_data;
}
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_GETRANDOM_H */
arch/s390/include/asm/vdso/gettimeofday.h
+1 -14
View File
@@ -14,12 +14,7 @@
#include <linux/compiler.h>
static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
{
return _vdso_data;
}
static inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_data *vd)
static inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_time_data *vd)
{
u64 adj, now;
@@ -49,12 +44,4 @@ long clock_getres_fallback(clockid_t clkid, struct __kernel_timespec *ts)
return syscall2(__NR_clock_getres, (long)clkid, (long)ts);
}
#ifdef CONFIG_TIME_NS
static __always_inline
const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
{
return _timens_data;
}
#endif
#endif
arch/s390/include/asm/vdso/vsyscall.h
-20
View File
@@ -2,32 +2,12 @@
#ifndef __ASM_VDSO_VSYSCALL_H
#define __ASM_VDSO_VSYSCALL_H
#define __VDSO_RND_DATA_OFFSET 768
#ifndef __ASSEMBLY__
#include <linux/hrtimer.h>
#include <vdso/datapage.h>
#include <asm/vdso.h>
enum vvar_pages {
VVAR_DATA_PAGE_OFFSET,
VVAR_TIMENS_PAGE_OFFSET,
VVAR_NR_PAGES
};
static __always_inline struct vdso_data *__s390_get_k_vdso_data(void)
{
return vdso_data;
}
#define __arch_get_k_vdso_data __s390_get_k_vdso_data
static __always_inline struct vdso_rng_data *__s390_get_k_vdso_rnd_data(void)
{
return (void *)vdso_data + __VDSO_RND_DATA_OFFSET;
}
#define __arch_get_k_vdso_rng_data __s390_get_k_vdso_rnd_data
/* The asm-generic header needs to be included after the definitions above */
#include <asm-generic/vdso/vsyscall.h>
arch/s390/kernel/time.c
+3 -3
View File
@@ -84,7 +84,7 @@ void __init time_early_init(void)
/* Initialize TOD steering parameters */
tod_steering_end = tod_clock_base.tod;
for (cs = 0; cs < CS_BASES; cs++)
vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
vdso_k_time_data[cs].arch_data.tod_steering_end = tod_steering_end;
if (!test_facility(28))
return;
@@ -390,8 +390,8 @@ static void clock_sync_global(long delta)
tod_steering_delta);
tod_steering_end = now + (abs(tod_steering_delta) << 15);
for (cs = 0; cs < CS_BASES; cs++) {
vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
vdso_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
vdso_k_time_data[cs].arch_data.tod_steering_end = tod_steering_end;
vdso_k_time_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
}
/* Update LPAR offset. */
arch/s390/kernel/vdso.c
+5 -92
View File
@@ -16,8 +16,8 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/time_namespace.h>
#include <linux/random.h>
#include <linux/vdso_datastore.h>
#include <vdso/datapage.h>
#include <asm/vdso/vsyscall.h>
#include <asm/alternative.h>
@@ -26,85 +26,6 @@
extern char vdso64_start[], vdso64_end[];
extern char vdso32_start[], vdso32_end[];
static struct vm_special_mapping vvar_mapping;
static union vdso_data_store vdso_data_store __page_aligned_data;
struct vdso_data *vdso_data = vdso_data_store.data;
#ifdef CONFIG_TIME_NS
struct vdso_data *arch_get_vdso_data(void *vvar_page)
{
return (struct vdso_data *)(vvar_page);
}
/*
* The VVAR page layout depends on whether a task belongs to the root or
* non-root time namespace. Whenever a task changes its namespace, the VVAR
* page tables are cleared and then they will be re-faulted with a
* corresponding layout.
* See also the comment near timens_setup_vdso_data() for details.
*/
int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
{
struct mm_struct *mm = task->mm;
VMA_ITERATOR(vmi, mm, 0);
struct vm_area_struct *vma;
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
if (!vma_is_special_mapping(vma, &vvar_mapping))
continue;
zap_vma_pages(vma);
break;
}
mmap_read_unlock(mm);
return 0;
}
#endif
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *timens_page = find_timens_vvar_page(vma);
unsigned long addr, pfn;
vm_fault_t err;
switch (vmf->pgoff) {
case VVAR_DATA_PAGE_OFFSET:
pfn = virt_to_pfn(vdso_data);
if (timens_page) {
/*
* Fault in VVAR page too, since it will be accessed
* to get clock data anyway.
*/
addr = vmf->address + VVAR_TIMENS_PAGE_OFFSET * PAGE_SIZE;
err = vmf_insert_pfn(vma, addr, pfn);
if (unlikely(err & VM_FAULT_ERROR))
return err;
pfn = page_to_pfn(timens_page);
}
break;
#ifdef CONFIG_TIME_NS
case VVAR_TIMENS_PAGE_OFFSET:
/*
* If a task belongs to a time namespace then a namespace
* specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
* the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
* offset.
* See also the comment near timens_setup_vdso_data().
*/
if (!timens_page)
return VM_FAULT_SIGBUS;
pfn = virt_to_pfn(vdso_data);
break;
#endif /* CONFIG_TIME_NS */
default:
return VM_FAULT_SIGBUS;
}
return vmf_insert_pfn(vma, vmf->address, pfn);
}
static int vdso_mremap(const struct vm_special_mapping *sm,
struct vm_area_struct *vma)
{
@@ -112,11 +33,6 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
return 0;
}
static struct vm_special_mapping vvar_mapping = {
.name = "[vvar]",
.fault = vvar_fault,
};
static struct vm_special_mapping vdso64_mapping = {
.name = "[vdso]",
.mremap = vdso_mremap,
@@ -142,7 +58,7 @@ static int map_vdso(unsigned long addr, unsigned long vdso_mapping_len)
struct vm_area_struct *vma;
int rc;
BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
BUILD_BUG_ON(VDSO_NR_PAGES != __VDSO_PAGES);
if (mmap_write_lock_killable(mm))
return -EINTR;
@@ -157,14 +73,11 @@ static int map_vdso(unsigned long addr, unsigned long vdso_mapping_len)
rc = vvar_start;
if (IS_ERR_VALUE(vvar_start))
goto out;
vma = _install_special_mapping(mm, vvar_start, VVAR_NR_PAGES*PAGE_SIZE,
VM_READ|VM_MAYREAD|VM_IO|VM_DONTDUMP|
VM_PFNMAP,
&vvar_mapping);
vma = vdso_install_vvar_mapping(mm, vvar_start);
rc = PTR_ERR(vma);
if (IS_ERR(vma))
goto out;
vdso_text_start = vvar_start + VVAR_NR_PAGES * PAGE_SIZE;
vdso_text_start = vvar_start + VDSO_NR_PAGES * PAGE_SIZE;
/* VM_MAYWRITE for COW so gdb can set breakpoints */
vma = _install_special_mapping(mm, vdso_text_start, vdso_text_len,
VM_READ|VM_EXEC|
@@ -220,7 +133,7 @@ unsigned long vdso_text_size(void)
unsigned long vdso_size(void)
{
return vdso_text_size() + VVAR_NR_PAGES * PAGE_SIZE;
return vdso_text_size() + VDSO_NR_PAGES * PAGE_SIZE;
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
arch/s390/kernel/vdso32/vdso32.lds.S
+3 -4
View File
@@ -6,16 +6,15 @@
#include <asm/page.h>
#include <asm/vdso.h>
#include <vdso/datapage.h>
OUTPUT_FORMAT("elf32-s390", "elf32-s390", "elf32-s390")
OUTPUT_ARCH(s390:31-bit)
SECTIONS
{
PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
#ifdef CONFIG_TIME_NS
PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
#endif
VDSO_VVAR_SYMS
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
arch/s390/kernel/vdso64/vdso64.lds.S
+3 -5
View File
@@ -7,17 +7,15 @@
#include <asm/vdso/vsyscall.h>
#include <asm/page.h>
#include <asm/vdso.h>
#include <vdso/datapage.h>
OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
OUTPUT_ARCH(s390:64-bit)
SECTIONS
{
PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
PROVIDE(_vdso_rng_data = _vdso_data + __VDSO_RND_DATA_OFFSET);
#ifdef CONFIG_TIME_NS
PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
#endif
VDSO_VVAR_SYMS
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text