All of lore.kernel.org
 help / color / mirror / Atom feed
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, 16 Jun 2020 00:55:40 -0700	[thread overview]
Message-ID: <20200616075545.312684-2-avagin@gmail.com> (raw)
In-Reply-To: <20200616075545.312684-1-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>
Reviewed-by: Dmitry Safonov <dima@arista.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 4e016574bd91..b0aec4e8c9b4 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -108,28 +108,32 @@ static int __vdso_init(enum vdso_abi abi)
 			PAGE_SHIFT;
 
 	/* Allocate the vDSO pagelist, plus a page for the data. */
-	vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages + 1,
+	vdso_pagelist = kcalloc(vdso_info[abi].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_info[abi].vdso_code_start);
 
 	for (i = 0; i < vdso_info[abi].vdso_pages; i++)
-		vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
+		vdso_pagelist[i] = pfn_to_page(pfn + i);
 
-	vdso_info[abi].dm->pages = &vdso_pagelist[0];
-	vdso_info[abi].cm->pages = &vdso_pagelist[1];
+	vdso_info[abi].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 vdso_abi abi,
 				    struct mm_struct *mm,
 				    struct linux_binprm *bprm,
@@ -150,7 +154,7 @@ static int __setup_additional_pages(enum vdso_abi abi,
 	}
 
 	ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
-				       VM_READ|VM_MAYREAD,
+				       VM_READ|VM_MAYREAD|VM_PFNMAP,
 				       vdso_info[abi].dm);
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -209,6 +213,7 @@ static struct vm_special_mapping aarch32_vdso_maps[] = {
 #ifdef CONFIG_COMPAT_VDSO
 	[AA32_MAP_VVAR] = {
 		.name = "[vvar]",
+		.fault = vvar_fault,
 	},
 	[AA32_MAP_VDSO] = {
 		.name = "[vdso]",
@@ -376,6 +381,7 @@ enum aarch64_map {
 static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = {
 	[AA64_MAP_VVAR] = {
 		.name	= "[vvar]",
+		.fault = vvar_fault,
 	},
 	[AA64_MAP_VDSO] = {
 		.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, 16 Jun 2020 00:55:40 -0700	[thread overview]
Message-ID: <20200616075545.312684-2-avagin@gmail.com> (raw)
In-Reply-To: <20200616075545.312684-1-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>
Reviewed-by: Dmitry Safonov <dima@arista.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 4e016574bd91..b0aec4e8c9b4 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -108,28 +108,32 @@ static int __vdso_init(enum vdso_abi abi)
 			PAGE_SHIFT;
 
 	/* Allocate the vDSO pagelist, plus a page for the data. */
-	vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages + 1,
+	vdso_pagelist = kcalloc(vdso_info[abi].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_info[abi].vdso_code_start);
 
 	for (i = 0; i < vdso_info[abi].vdso_pages; i++)
-		vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
+		vdso_pagelist[i] = pfn_to_page(pfn + i);
 
-	vdso_info[abi].dm->pages = &vdso_pagelist[0];
-	vdso_info[abi].cm->pages = &vdso_pagelist[1];
+	vdso_info[abi].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 vdso_abi abi,
 				    struct mm_struct *mm,
 				    struct linux_binprm *bprm,
@@ -150,7 +154,7 @@ static int __setup_additional_pages(enum vdso_abi abi,
 	}
 
 	ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
-				       VM_READ|VM_MAYREAD,
+				       VM_READ|VM_MAYREAD|VM_PFNMAP,
 				       vdso_info[abi].dm);
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -209,6 +213,7 @@ static struct vm_special_mapping aarch32_vdso_maps[] = {
 #ifdef CONFIG_COMPAT_VDSO
 	[AA32_MAP_VVAR] = {
 		.name = "[vvar]",
+		.fault = vvar_fault,
 	},
 	[AA32_MAP_VDSO] = {
 		.name = "[vdso]",
@@ -376,6 +381,7 @@ enum aarch64_map {
 static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = {
 	[AA64_MAP_VVAR] = {
 		.name	= "[vvar]",
+		.fault = vvar_fault,
 	},
 	[AA64_MAP_VDSO] = {
 		.name	= "[vdso]",
-- 
2.24.1


  reply	other threads:[~2020-06-16  7:56 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-16  7:55 [PATCH v4 0/6] arm64: add the time namespace support Andrei Vagin
2020-06-16  7:55 ` Andrei Vagin
2020-06-16  7:55 ` Andrei Vagin [this message]
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
2020-06-16 10:59     ` Mark Rutland
2020-06-18  7:27     ` Andrei Vagin
2020-06-18  7:27       ` Andrei Vagin
2020-06-16  7:55 ` [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace Andrei Vagin
2020-06-16  7:55   ` Andrei Vagin
2020-06-16 11:24   ` Mark Rutland
2020-06-16 11:24     ` Mark Rutland
2020-06-16 13:47     ` Dmitry Safonov
2020-06-16 13:47       ` Dmitry Safonov
2020-06-19 15:38   ` Christian Brauner
2020-06-19 15:38     ` Christian Brauner
2020-06-23  7:33     ` Andrei Vagin
2020-06-23  8:40       ` Christian Brauner
2020-06-16  7:55 ` [PATCH 3/6] arm64/vdso: Add time namespace page Andrei Vagin
2020-06-16  7:55   ` Andrei Vagin
2020-06-16  7:55 ` [PATCH 4/6] arm64/vdso: Handle faults on timens page Andrei Vagin
2020-06-16  7:55   ` Andrei Vagin
2020-06-16  7:55 ` [PATCH 5/6] arm64/vdso: Restrict splitting VVAR VMA Andrei Vagin
2020-06-16  7:55   ` Andrei Vagin
2020-06-16  7:55 ` [PATCH 6/6] arm64: enable time namespace support Andrei Vagin
2020-06-16  7:55   ` Andrei Vagin
  -- strict thread matches above, loose matches on Subject: below --
2020-06-24  8:33 [PATCH v5 0/6] arm64: add the " 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
2020-06-02 18:02 [PATCH RESEND v3 0/6] arm64: add the time namespace support Andrei Vagin
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   ` 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200616075545.312684-2-avagin@gmail.com \
    --to=avagin@gmail.com \
    --cc=catalin.marinas@arm.com \
    --cc=dima@arista.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=tglx@linutronix.de \
    --cc=vincenzo.frascino@arm.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.