| Message ID | 20200225073731.465270-2-avagin@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: add the time namespace support | expand |
On 2/25/20 7:37 AM, Andrei Vagin wrote: > This is required to support time namespaces where a time namespace data > page is different for each namespace. > > Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > --- > arch/arm64/kernel/vdso.c | 24 +++++++++++++++--------- > 1 file changed, 15 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index 354b11e27c07..290c36d74e03 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -114,28 +114,32 @@ static int __vdso_init(enum arch_vdso_type arch_index) > PAGE_SHIFT; > > /* Allocate the vDSO pagelist, plus a page for the data. */ > - vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages + 1, > + vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages, > sizeof(struct page *), > GFP_KERNEL); > if (vdso_pagelist == NULL) > return -ENOMEM; > > - /* Grab the vDSO data page. */ > - vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data)); > - > - > /* Grab the vDSO code pages. */ > pfn = sym_to_pfn(vdso_lookup[arch_index].vdso_code_start); > > for (i = 0; i < vdso_lookup[arch_index].vdso_pages; i++) > - vdso_pagelist[i + 1] = pfn_to_page(pfn + i); > + vdso_pagelist[i] = pfn_to_page(pfn + i); > > - vdso_lookup[arch_index].dm->pages = &vdso_pagelist[0]; > - vdso_lookup[arch_index].cm->pages = &vdso_pagelist[1]; > + vdso_lookup[arch_index].cm->pages = vdso_pagelist; > > return 0; > } > > +static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, > + struct vm_area_struct *vma, struct vm_fault *vmf) > +{ > + if (vmf->pgoff == 0) > + return vmf_insert_pfn(vma, vmf->address, > + sym_to_pfn(vdso_data)); > + return VM_FAULT_SIGBUS; > +} > + > static int __setup_additional_pages(enum arch_vdso_type arch_index, > struct mm_struct *mm, > struct linux_binprm *bprm, > @@ -155,7 +159,7 @@ static int __setup_additional_pages(enum arch_vdso_type arch_index, > } > > ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, > - VM_READ|VM_MAYREAD, > + VM_READ|VM_MAYREAD|VM_PFNMAP, > vdso_lookup[arch_index].dm); > if (IS_ERR(ret)) > goto up_fail; > @@ -215,6 +219,7 @@ static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { > #ifdef CONFIG_COMPAT_VDSO > { > .name = "[vvar]", > + .fault = vvar_fault, > }, > { > .name = "[vdso]", > @@ -396,6 +401,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > static struct vm_special_mapping vdso_spec[A_PAGES] __ro_after_init = { > { > .name = "[vvar]", > + .fault = vvar_fault, > }, > { > .name = "[vdso]", >
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 354b11e27c07..290c36d74e03 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -114,28 +114,32 @@ static int __vdso_init(enum arch_vdso_type arch_index) PAGE_SHIFT; /* Allocate the vDSO pagelist, plus a page for the data. */ - vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages + 1, + vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages, sizeof(struct page *), GFP_KERNEL); if (vdso_pagelist == NULL) return -ENOMEM; - /* Grab the vDSO data page. */ - vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data)); - - /* Grab the vDSO code pages. */ pfn = sym_to_pfn(vdso_lookup[arch_index].vdso_code_start); for (i = 0; i < vdso_lookup[arch_index].vdso_pages; i++) - vdso_pagelist[i + 1] = pfn_to_page(pfn + i); + vdso_pagelist[i] = pfn_to_page(pfn + i); - vdso_lookup[arch_index].dm->pages = &vdso_pagelist[0]; - vdso_lookup[arch_index].cm->pages = &vdso_pagelist[1]; + vdso_lookup[arch_index].cm->pages = vdso_pagelist; return 0; } +static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, + struct vm_area_struct *vma, struct vm_fault *vmf) +{ + if (vmf->pgoff == 0) + return vmf_insert_pfn(vma, vmf->address, + sym_to_pfn(vdso_data)); + return VM_FAULT_SIGBUS; +} + static int __setup_additional_pages(enum arch_vdso_type arch_index, struct mm_struct *mm, struct linux_binprm *bprm, @@ -155,7 +159,7 @@ static int __setup_additional_pages(enum arch_vdso_type arch_index, } ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, - VM_READ|VM_MAYREAD, + VM_READ|VM_MAYREAD|VM_PFNMAP, vdso_lookup[arch_index].dm); if (IS_ERR(ret)) goto up_fail; @@ -215,6 +219,7 @@ static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { #ifdef CONFIG_COMPAT_VDSO { .name = "[vvar]", + .fault = vvar_fault, }, { .name = "[vdso]", @@ -396,6 +401,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, static struct vm_special_mapping vdso_spec[A_PAGES] __ro_after_init = { { .name = "[vvar]", + .fault = vvar_fault, }, { .name = "[vdso]",
This is required to support time namespaces where a time namespace data page is different for each namespace. Signed-off-by: Andrei Vagin <avagin@gmail.com> --- arch/arm64/kernel/vdso.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-)