From: Andrei Vagin <avagin@gmail.com>
To: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andrei Vagin <avagin@gmail.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Dmitry Safonov <dima@arista.com>
Subject: [PATCH v2 1/6] arm64/vdso: use the fault callback to map vvar pages
Date: Mon, 24 Feb 2020 23:37:26 -0800 [thread overview]
Message-ID: <20200225073731.465270-2-avagin@gmail.com> (raw)
In-Reply-To: <20200225073731.465270-1-avagin@gmail.com>
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(-)
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]",
--
2.24.1
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next prev parent reply other threads:[~2020-02-25 7:38 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-25 7:37 [PATCH v2 0/6] arm64: add the time namespace support Andrei Vagin
2020-02-25 7:37 ` Andrei Vagin [this message]
2020-04-09 12:01 ` [PATCH v2 1/6] arm64/vdso: use the fault callback to map vvar pages Vincenzo Frascino
2020-02-25 7:37 ` [PATCH v2 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace Andrei Vagin
2020-04-09 12:01 ` Vincenzo Frascino
2020-02-25 7:37 ` [PATCH v2 3/6] arm64/vdso: Add time napespace page Andrei Vagin
2020-04-09 12:03 ` Vincenzo Frascino
2020-04-14 17:20 ` Mark Rutland
2020-04-15 2:34 ` Andrei Vagin
2020-04-15 10:05 ` Mark Rutland
2020-04-15 10:16 ` Vincenzo Frascino
2020-04-15 12:27 ` Mark Rutland
2020-02-25 7:37 ` [PATCH v2 4/6] arm64/vdso: Handle faults on timens page Andrei Vagin
2020-04-09 12:04 ` Vincenzo Frascino
2020-02-25 7:37 ` [PATCH v2 5/6] arm64/vdso: Restrict splitting VVAR VMA Andrei Vagin
2020-04-09 12:05 ` Vincenzo Frascino
2020-02-25 7:37 ` [PATCH v2 6/6] arm64: enable time namespace support Andrei Vagin
2020-04-09 12:06 ` Vincenzo Frascino
2020-04-01 6:50 ` [PATCH v2 0/6] arm64: add the " Andrei Vagin
2020-04-01 9:02 ` Vincenzo Frascino
2020-04-09 13:24 ` Vincenzo Frascino
2020-04-11 7:33 ` Andrei Vagin
2020-04-14 9:02 ` Vincenzo Frascino
2020-04-15 16:14 ` Andrei Vagin
2020-04-15 16:35 ` Vincenzo Frascino
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