2019-06-02 22:44:50 -07:00
|
|
|
// SPDX-License-Identifier: GPL-2.0-only
|
2017-07-10 18:00:26 -07:00
|
|
|
/*
|
|
|
|
* Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
|
|
|
|
* <benh@kernel.crashing.org>
|
|
|
|
* Copyright (C) 2012 ARM Limited
|
|
|
|
* Copyright (C) 2015 Regents of the University of California
|
|
|
|
*/
|
|
|
|
|
2019-10-17 15:21:28 -07:00
|
|
|
#include <linux/elf.h>
|
2017-07-10 18:00:26 -07:00
|
|
|
#include <linux/mm.h>
|
|
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/binfmts.h>
|
|
|
|
#include <linux/err.h>
|
2020-06-09 07:14:48 -07:00
|
|
|
#include <asm/page.h>
|
2021-08-31 19:46:19 -07:00
|
|
|
#include <asm/vdso.h>
|
2021-08-31 20:20:25 -07:00
|
|
|
#include <linux/time_namespace.h>
|
2020-06-09 07:14:48 -07:00
|
|
|
#include <vdso/datapage.h>
|
2023-06-16 04:43:57 -07:00
|
|
|
#include <vdso/vsyscall.h>
|
2017-07-10 18:00:26 -07:00
|
|
|
|
riscv/vdso: Move vdso data page up front
As commit 601255ae3c98 ("arm64: vdso: move data page before code pages"), the
same issue exists on riscv, testcase is shown below, make sure that vdso.so is
bigger than page size,
struct timespec tp;
clock_gettime(5, &tp);
printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec);
without this patch, test result : tv_sec: 0, tv_nsec: 0
with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000
Move the vdso data page in front of the VDSO area to fix the issue.
Fixes: ad5d1122b82fb ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-31 19:46:20 -07:00
|
|
|
enum vvar_pages {
|
|
|
|
VVAR_DATA_PAGE_OFFSET,
|
2021-08-31 20:20:25 -07:00
|
|
|
VVAR_TIMENS_PAGE_OFFSET,
|
riscv/vdso: Move vdso data page up front
As commit 601255ae3c98 ("arm64: vdso: move data page before code pages"), the
same issue exists on riscv, testcase is shown below, make sure that vdso.so is
bigger than page size,
struct timespec tp;
clock_gettime(5, &tp);
printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec);
without this patch, test result : tv_sec: 0, tv_nsec: 0
with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000
Move the vdso data page in front of the VDSO area to fix the issue.
Fixes: ad5d1122b82fb ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-31 19:46:20 -07:00
|
|
|
VVAR_NR_PAGES,
|
|
|
|
};
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
enum rv_vdso_map {
|
|
|
|
RV_VDSO_MAP_VVAR,
|
|
|
|
RV_VDSO_MAP_VDSO,
|
|
|
|
};
|
|
|
|
|
riscv/vdso: Move vdso data page up front
As commit 601255ae3c98 ("arm64: vdso: move data page before code pages"), the
same issue exists on riscv, testcase is shown below, make sure that vdso.so is
bigger than page size,
struct timespec tp;
clock_gettime(5, &tp);
printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec);
without this patch, test result : tv_sec: 0, tv_nsec: 0
with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000
Move the vdso data page in front of the VDSO area to fix the issue.
Fixes: ad5d1122b82fb ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-31 19:46:20 -07:00
|
|
|
#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
|
|
|
|
|
2024-02-20 01:52:12 -07:00
|
|
|
static union vdso_data_store vdso_data_store __page_aligned_data;
|
|
|
|
struct vdso_data *vdso_data = vdso_data_store.data;
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
struct __vdso_info {
|
|
|
|
const char *name;
|
|
|
|
const char *vdso_code_start;
|
|
|
|
const char *vdso_code_end;
|
|
|
|
unsigned long vdso_pages;
|
|
|
|
/* Data Mapping */
|
|
|
|
struct vm_special_mapping *dm;
|
|
|
|
/* Code Mapping */
|
|
|
|
struct vm_special_mapping *cm;
|
|
|
|
};
|
|
|
|
|
2022-09-24 00:07:37 -07:00
|
|
|
static struct __vdso_info vdso_info;
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
static struct __vdso_info compat_vdso_info;
|
|
|
|
#endif
|
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
static int vdso_mremap(const struct vm_special_mapping *sm,
|
|
|
|
struct vm_area_struct *new_vma)
|
|
|
|
{
|
|
|
|
current->mm->context.vdso = (void *)new_vma->vm_start;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
static void __init __vdso_init(struct __vdso_info *vdso_info)
|
2017-07-10 18:00:26 -07:00
|
|
|
{
|
|
|
|
unsigned int i;
|
2021-08-31 20:20:25 -07:00
|
|
|
struct page **vdso_pagelist;
|
|
|
|
unsigned long pfn;
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4))
|
|
|
|
panic("vDSO is not a valid ELF object!\n");
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
vdso_info->vdso_pages = (
|
|
|
|
vdso_info->vdso_code_end -
|
|
|
|
vdso_info->vdso_code_start) >>
|
2021-08-31 20:20:25 -07:00
|
|
|
PAGE_SHIFT;
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
vdso_pagelist = kcalloc(vdso_info->vdso_pages,
|
2021-08-31 20:20:25 -07:00
|
|
|
sizeof(struct page *),
|
|
|
|
GFP_KERNEL);
|
|
|
|
if (vdso_pagelist == NULL)
|
2022-04-05 00:13:11 -07:00
|
|
|
panic("vDSO kcalloc failed!\n");
|
2021-08-31 20:20:25 -07:00
|
|
|
|
|
|
|
/* Grab the vDSO code pages. */
|
2022-04-05 00:13:11 -07:00
|
|
|
pfn = sym_to_pfn(vdso_info->vdso_code_start);
|
2021-08-31 20:20:25 -07:00
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
for (i = 0; i < vdso_info->vdso_pages; i++)
|
2021-08-31 20:20:25 -07:00
|
|
|
vdso_pagelist[i] = pfn_to_page(pfn + i);
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
vdso_info->cm->pages = vdso_pagelist;
|
2021-08-31 20:20:25 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef CONFIG_TIME_NS
|
|
|
|
struct vdso_data *arch_get_vdso_data(void *vvar_page)
|
|
|
|
{
|
|
|
|
return (struct vdso_data *)(vvar_page);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The vvar mapping contains data for a specific time namespace, so when a task
|
|
|
|
* changes namespace we must unmap its vvar data for the old namespace.
|
|
|
|
* Subsequent faults will map in data for the new namespace.
|
|
|
|
*
|
|
|
|
* For more details see timens_setup_vdso_data().
|
|
|
|
*/
|
|
|
|
int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
|
|
|
|
{
|
|
|
|
struct mm_struct *mm = task->mm;
|
|
|
|
struct vm_area_struct *vma;
|
2022-09-06 12:49:05 -07:00
|
|
|
VMA_ITERATOR(vmi, mm, 0);
|
2021-08-31 20:20:25 -07:00
|
|
|
|
|
|
|
mmap_read_lock(mm);
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2022-09-06 12:49:05 -07:00
|
|
|
for_each_vma(vmi, vma) {
|
2022-09-24 00:07:37 -07:00
|
|
|
if (vma_is_special_mapping(vma, vdso_info.dm))
|
2023-01-03 17:27:32 -07:00
|
|
|
zap_vma_pages(vma);
|
2022-09-24 00:07:37 -07:00
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
if (vma_is_special_mapping(vma, compat_vdso_info.dm))
|
2023-01-03 17:27:32 -07:00
|
|
|
zap_vma_pages(vma);
|
2022-09-24 00:07:37 -07:00
|
|
|
#endif
|
2017-07-10 18:00:26 -07:00
|
|
|
}
|
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
mmap_read_unlock(mm);
|
2017-07-10 18:00:26 -07:00
|
|
|
return 0;
|
|
|
|
}
|
2021-08-31 20:20:25 -07:00
|
|
|
#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 pfn;
|
|
|
|
|
|
|
|
switch (vmf->pgoff) {
|
|
|
|
case VVAR_DATA_PAGE_OFFSET:
|
|
|
|
if (timens_page)
|
|
|
|
pfn = page_to_pfn(timens_page);
|
|
|
|
else
|
|
|
|
pfn = sym_to_pfn(vdso_data);
|
|
|
|
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 = sym_to_pfn(vdso_data);
|
|
|
|
break;
|
|
|
|
#endif /* CONFIG_TIME_NS */
|
|
|
|
default:
|
|
|
|
return VM_FAULT_SIGBUS;
|
|
|
|
}
|
|
|
|
|
|
|
|
return vmf_insert_pfn(vma, vmf->address, pfn);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
|
|
|
|
[RV_VDSO_MAP_VVAR] = {
|
|
|
|
.name = "[vvar]",
|
|
|
|
.fault = vvar_fault,
|
|
|
|
},
|
|
|
|
[RV_VDSO_MAP_VDSO] = {
|
|
|
|
.name = "[vdso]",
|
|
|
|
.mremap = vdso_mremap,
|
|
|
|
},
|
|
|
|
};
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
static struct __vdso_info vdso_info __ro_after_init = {
|
|
|
|
.name = "vdso",
|
|
|
|
.vdso_code_start = vdso_start,
|
|
|
|
.vdso_code_end = vdso_end,
|
|
|
|
.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
|
|
|
|
.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
|
|
|
|
};
|
|
|
|
|
|
|
|
#ifdef CONFIG_COMPAT
|
2022-05-25 09:04:04 -07:00
|
|
|
static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = {
|
|
|
|
[RV_VDSO_MAP_VVAR] = {
|
|
|
|
.name = "[vvar]",
|
|
|
|
.fault = vvar_fault,
|
|
|
|
},
|
|
|
|
[RV_VDSO_MAP_VDSO] = {
|
|
|
|
.name = "[vdso]",
|
|
|
|
.mremap = vdso_mremap,
|
|
|
|
},
|
|
|
|
};
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
static struct __vdso_info compat_vdso_info __ro_after_init = {
|
|
|
|
.name = "compat_vdso",
|
|
|
|
.vdso_code_start = compat_vdso_start,
|
|
|
|
.vdso_code_end = compat_vdso_end,
|
2022-05-25 09:04:04 -07:00
|
|
|
.dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR],
|
|
|
|
.cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO],
|
2022-04-05 00:13:11 -07:00
|
|
|
};
|
|
|
|
#endif
|
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
static int __init vdso_init(void)
|
|
|
|
{
|
2022-04-05 00:13:11 -07:00
|
|
|
__vdso_init(&vdso_info);
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
__vdso_init(&compat_vdso_info);
|
|
|
|
#endif
|
2021-08-31 20:20:25 -07:00
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
return 0;
|
2021-08-31 20:20:25 -07:00
|
|
|
}
|
2017-07-10 18:00:26 -07:00
|
|
|
arch_initcall(vdso_init);
|
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
static int __setup_additional_pages(struct mm_struct *mm,
|
|
|
|
struct linux_binprm *bprm,
|
2022-04-05 00:13:11 -07:00
|
|
|
int uses_interp,
|
|
|
|
struct __vdso_info *vdso_info)
|
2017-07-10 18:00:26 -07:00
|
|
|
{
|
2021-08-31 20:20:25 -07:00
|
|
|
unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
|
|
|
|
void *ret;
|
2017-07-10 18:00:26 -07:00
|
|
|
|
riscv/vdso: Move vdso data page up front
As commit 601255ae3c98 ("arm64: vdso: move data page before code pages"), the
same issue exists on riscv, testcase is shown below, make sure that vdso.so is
bigger than page size,
struct timespec tp;
clock_gettime(5, &tp);
printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec);
without this patch, test result : tv_sec: 0, tv_nsec: 0
with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000
Move the vdso data page in front of the VDSO area to fix the issue.
Fixes: ad5d1122b82fb ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-31 19:46:20 -07:00
|
|
|
BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
|
2021-08-31 20:20:25 -07:00
|
|
|
/* Be sure to map the data page */
|
|
|
|
vdso_mapping_len = vdso_text_len + VVAR_SIZE;
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
|
2018-01-22 05:44:02 -07:00
|
|
|
if (IS_ERR_VALUE(vdso_base)) {
|
2021-08-31 20:20:25 -07:00
|
|
|
ret = ERR_PTR(vdso_base);
|
|
|
|
goto up_fail;
|
2017-07-10 18:00:26 -07:00
|
|
|
}
|
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
|
2022-04-05 00:13:11 -07:00
|
|
|
(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
|
2021-08-31 20:20:25 -07:00
|
|
|
if (IS_ERR(ret))
|
|
|
|
goto up_fail;
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
vdso_base += VVAR_SIZE;
|
|
|
|
mm->context.vdso = (void *)vdso_base;
|
2022-04-05 00:13:11 -07:00
|
|
|
|
2020-06-09 07:14:49 -07:00
|
|
|
ret =
|
2021-08-31 20:20:25 -07:00
|
|
|
_install_special_mapping(mm, vdso_base, vdso_text_len,
|
2017-07-10 18:00:26 -07:00
|
|
|
(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
|
2022-04-05 00:13:11 -07:00
|
|
|
vdso_info->cm);
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
if (IS_ERR(ret))
|
|
|
|
goto up_fail;
|
2017-07-10 18:00:26 -07:00
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
return 0;
|
2020-06-09 07:14:49 -07:00
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
up_fail:
|
|
|
|
mm->context.vdso = NULL;
|
|
|
|
return PTR_ERR(ret);
|
2017-07-10 18:00:26 -07:00
|
|
|
}
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
|
|
|
|
int uses_interp)
|
|
|
|
{
|
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (mmap_write_lock_killable(mm))
|
|
|
|
return -EINTR;
|
|
|
|
|
|
|
|
ret = __setup_additional_pages(mm, bprm, uses_interp,
|
|
|
|
&compat_vdso_info);
|
|
|
|
mmap_write_unlock(mm);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
2021-08-31 20:20:25 -07:00
|
|
|
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
|
2017-07-10 18:00:26 -07:00
|
|
|
{
|
2021-08-31 20:20:25 -07:00
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (mmap_write_lock_killable(mm))
|
|
|
|
return -EINTR;
|
|
|
|
|
2022-04-05 00:13:11 -07:00
|
|
|
ret = __setup_additional_pages(mm, bprm, uses_interp, &vdso_info);
|
2021-08-31 20:20:25 -07:00
|
|
|
mmap_write_unlock(mm);
|
|
|
|
|
|
|
|
return ret;
|
2017-07-10 18:00:26 -07:00
|
|
|
}
|