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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: Mark Rutland <mark.rutland@arm.com>,
	Dmitry Safonov <dima@arista.com>,
	linux-kernel@vger.kernel.org, Andrei Vagin <avagin@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vincenzo Frascino <vincenzo.frascino@arm.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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
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


  reply	other threads:[~2020-06-02 18:03 UTC|newest]

Thread overview: 43+ 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
2020-06-02 18:02 ` Andrei Vagin [this message]
2020-06-02 18:02   ` [PATCH 1/6] arm64/vdso: use the fault callback to map vvar pages Andrei Vagin
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   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 3/6] arm64/vdso: Add time namespace page Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 19:29   ` Dmitry Safonov
2020-06-02 19:29     ` Dmitry Safonov
2020-06-02 22:04   ` kbuild test robot
2020-06-02 22:04     ` kbuild test robot
2020-06-02 22:04     ` kbuild test robot
2020-06-03  6:42   ` kbuild test robot
2020-06-03  6:42     ` kbuild test robot
2020-06-03  6:42     ` kbuild test robot
2020-06-05  7:45   ` [PATCH 3/6 v4] " Andrei Vagin
2020-06-05  7:45     ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 4/6] arm64/vdso: Handle faults on timens page Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 5/6] arm64/vdso: Restrict splitting VVAR VMA Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 6/6] arm64: enable time namespace support Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 19:31 ` [PATCH RESEND v3 0/6] arm64: add the " Dmitry Safonov
2020-06-02 19:31   ` Dmitry Safonov
2020-06-05 10:49 ` Mark Rutland
2020-06-05 10:49   ` Mark Rutland
2020-06-06  8:58   ` Andrei Vagin
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
2020-06-24  8:33   ` Andrei Vagin
2020-07-24 17:26   ` Catalin Marinas
2020-07-27  6:45     ` Andrei Vagin
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  7:55   ` Andrei Vagin
2020-06-16 10:59   ` Mark Rutland
2020-06-16 10:59     ` Mark Rutland
2020-06-18  7:27     ` Andrei Vagin
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
2020-04-16  5:26   ` Andrei Vagin

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