From: Andrei Vagin <avagin@gmail.com>
To: linux-arm-kernel@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Dmitry Safonov <dima@arista.com>, Andrei Vagin <avagin@gmail.com>
Subject: [PATCH 1/6] arm64/vdso: use the fault callback to map vvar pages
Date: Tue, 2 Jun 2020 11:02:54 -0700 [thread overview]
Message-ID: <20200602180259.76361-2-avagin@gmail.com> (raw)
In-Reply-To: <20200602180259.76361-1-avagin@gmail.com>
This is required to support time namespaces where a time namespace data
page is different for each namespace.
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
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 033a48f30dbb..031ee1a8d4a8 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]",
@@ -385,6 +390,7 @@ 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
next prev parent reply other threads:[~2020-06-02 18:03 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-02 18:02 [PATCH RESEND v3 0/6] arm64: add the time namespace support Andrei Vagin
2020-06-02 18:02 ` Andrei Vagin [this message]
2020-06-02 18:02 ` [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace Andrei Vagin
2020-06-02 18:02 ` [PATCH 3/6] arm64/vdso: Add time namespace page Andrei Vagin
2020-06-02 19:29 ` Dmitry Safonov
2020-06-02 22:04 ` kbuild test robot
2020-06-03 6:42 ` kbuild test robot
2020-06-05 7:45 ` [PATCH 3/6 v4] " Andrei Vagin
2020-06-02 18:02 ` [PATCH 4/6] arm64/vdso: Handle faults on timens page Andrei Vagin
2020-06-02 18:02 ` [PATCH 5/6] arm64/vdso: Restrict splitting VVAR VMA Andrei Vagin
2020-06-02 18:02 ` [PATCH 6/6] arm64: enable time namespace support Andrei Vagin
2020-06-02 19:31 ` [PATCH RESEND v3 0/6] arm64: add the " Dmitry Safonov
2020-06-05 10:49 ` Mark Rutland
2020-06-06 8:58 ` Andrei Vagin
-- strict thread matches above, loose matches on Subject: below --
2020-06-24 8:33 [PATCH v5 " Andrei Vagin
2020-06-24 8:33 ` [PATCH 1/6] arm64/vdso: use the fault callback to map vvar pages Andrei Vagin
2020-07-24 17:26 ` Catalin Marinas
2020-07-27 6:45 ` Andrei Vagin
2020-06-16 7:55 [PATCH v4 0/6] arm64: add the time namespace support Andrei Vagin
2020-06-16 7:55 ` [PATCH 1/6] arm64/vdso: use the fault callback to map vvar pages Andrei Vagin
2020-06-16 10:59 ` Mark Rutland
2020-06-18 7:27 ` Andrei Vagin
2020-04-16 5:26 [PATCH v3 0/6] arm64: add the time namespace support Andrei Vagin
2020-04-16 5:26 ` [PATCH 1/6] arm64/vdso: use the fault callback to map vvar pages Andrei Vagin
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