From: Anshuman Khandual <anshuman.khandual@arm.com>
To: linux-mm@kvack.org
Cc: hughd@google.com, vbabka@suse.cz,
Anshuman Khandual <anshuman.khandual@arm.com>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Salter <msalter@redhat.com>, Nick Hu <nickhu@andestech.com>,
Ley Foon Tan <ley.foon.tan@intel.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Guan Xuetao <gxt@pku.edu.cn>,
Dave Hansen <dave.hansen@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Rob Springer <rspringer@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] mm/vma: Introduce VM_ACCESS_FLAGS
Date: Thu, 5 Mar 2020 12:20:14 +0530 [thread overview]
Message-ID: <1583391014-8170-3-git-send-email-anshuman.khandual@arm.com> (raw)
In-Reply-To: <1583391014-8170-1-git-send-email-anshuman.khandual@arm.com>
There are many places where all basic VMA access flags (read, write, exec)
are initialized or checked against as a group. One such example is during
page fault. Existing vma_is_accessible() wrapper already creates the notion
of VMA accessibility as a group access permissions. Hence lets just create
VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code
duplication but also extend the VMA accessibility concept in general.
Cc: Russell King <linux@armlinux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Mark Salter <msalter@redhat.com>
Cc: Nick Hu <nickhu@andestech.com>
CC: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Springer <rspringer@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
arch/arm/mm/fault.c | 2 +-
arch/arm64/mm/fault.c | 2 +-
arch/nds32/mm/fault.c | 2 +-
arch/powerpc/mm/book3s64/pkeys.c | 2 +-
arch/s390/mm/fault.c | 2 +-
arch/unicore32/mm/fault.c | 2 +-
arch/x86/mm/pkeys.c | 2 +-
drivers/staging/gasket/gasket_core.c | 2 +-
include/linux/mm.h | 6 +++++-
mm/mmap.c | 2 +-
mm/mprotect.c | 4 ++--
11 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index bd0f4821f7e1..2c71028d9d6b 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -189,7 +189,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
*/
static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
{
- unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned int mask = VM_ACCESS_FLAGS;
if ((fsr & FSR_WRITE) && !(fsr & FSR_CM))
mask = VM_WRITE;
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 85566d32958f..63f31206a12e 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -445,7 +445,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
const struct fault_info *inf;
struct mm_struct *mm = current->mm;
vm_fault_t fault, major = 0;
- unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned long vm_flags = VM_ACCESS_FLAGS;
unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (kprobe_page_fault(regs, esr))
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c
index 906dfb25353c..55387a31bf42 100644
--- a/arch/nds32/mm/fault.c
+++ b/arch/nds32/mm/fault.c
@@ -79,7 +79,7 @@ void do_page_fault(unsigned long entry, unsigned long addr,
struct vm_area_struct *vma;
int si_code;
vm_fault_t fault;
- unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned int mask = VM_ACCESS_FLAGS;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
error_code = error_code & (ITYPE_mskINST | ITYPE_mskETYPE);
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 59e0ebbd8036..11fd52b24f68 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -315,7 +315,7 @@ int __execute_only_pkey(struct mm_struct *mm)
static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
{
/* Do this check first since the vm_flags should be hot */
- if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+ if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
return false;
return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 7b0bb475c166..b2cb3c0d0e1a 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -584,7 +584,7 @@ void do_dat_exception(struct pt_regs *regs)
int access;
vm_fault_t fault;
- access = VM_READ | VM_EXEC | VM_WRITE;
+ access = VM_ACCESS_FLAGS;
fault = do_exception(regs, access);
if (unlikely(fault))
do_fault_error(regs, access, fault);
diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index 76342de9cf8c..fc27c274d358 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -149,7 +149,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
*/
static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
{
- unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned int mask = VM_ACCESS_FLAGS;
if (!(fsr ^ 0x12)) /* write? */
mask = VM_WRITE;
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index c6f84c0b5d7a..8873ed1438a9 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -63,7 +63,7 @@ int __execute_only_pkey(struct mm_struct *mm)
static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
{
/* Do this check first since the vm_flags should be hot */
- if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+ if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
return false;
if (vma_pkey(vma) != vma->vm_mm->context.execute_only_pkey)
return false;
diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c
index be6b50f454b4..81bb7d58dc49 100644
--- a/drivers/staging/gasket/gasket_core.c
+++ b/drivers/staging/gasket/gasket_core.c
@@ -689,7 +689,7 @@ static bool gasket_mmap_has_permissions(struct gasket_dev *gasket_dev,
/* Make sure that no wrong flags are set. */
requested_permissions =
- (vma->vm_flags & (VM_WRITE | VM_READ | VM_EXEC));
+ (vma->vm_flags & VM_ACCESS_FLAGS);
if (requested_permissions & ~(bar_permissions)) {
dev_dbg(gasket_dev->dev,
"Attempting to map a region with requested permissions "
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3861524368a4..e89512f1c170 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -368,6 +368,10 @@ extern unsigned int kobjsize(const void *objp);
#define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
+/* VMA basic access permission flags */
+#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
+
+
/*
* Special vmas that are non-mergable, non-mlock()able.
* Note: mm/huge_memory.c VM_NO_THP depends on this definition.
@@ -557,7 +561,7 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
static inline bool vma_is_accessible(struct vm_area_struct *vma)
{
- return vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
+ return vma->vm_flags & VM_ACCESS_FLAGS;
}
#ifdef CONFIG_SHMEM
diff --git a/mm/mmap.c b/mm/mmap.c
index 0d295f49b24d..57f74ade19a0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1221,7 +1221,7 @@ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct *
return a->vm_end == b->vm_start &&
mpol_equal(vma_policy(a), vma_policy(b)) &&
a->vm_file == b->vm_file &&
- !((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC|VM_SOFTDIRTY)) &&
+ !((a->vm_flags ^ b->vm_flags) & ~(VM_ACCESS_FLAGS | VM_SOFTDIRTY)) &&
b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT);
}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 7a8e84f86831..8fbb7e7c08a5 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -359,7 +359,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
*/
if (arch_has_pfn_modify_check() &&
(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
- (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) {
+ (newflags & VM_ACCESS_FLAGS) == 0) {
pgprot_t new_pgprot = vm_get_page_prot(newflags);
error = walk_page_range(current->mm, start, end,
@@ -538,7 +538,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
newflags |= (vma->vm_flags & ~mask_off_old_flags);
/* newflags >> 4 shift VM_MAY% in place of VM_% */
- if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
+ if ((newflags & ~(newflags >> 4)) & VM_ACCESS_FLAGS) {
error = -EACCES;
goto out;
}
--
2.20.1
next prev parent reply other threads:[~2020-03-05 6:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-05 6:50 [PATCH 0/2] mm/vma: some new flags Anshuman Khandual
2020-03-05 6:50 ` [PATCH 1/2] mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS Anshuman Khandual
2020-03-05 6:50 ` Anshuman Khandual [this message]
2020-03-05 12:11 ` [PATCH 2/2] mm/vma: Introduce VM_ACCESS_FLAGS Vlastimil Babka
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=1583391014-8170-3-git-send-email-anshuman.khandual@arm.com \
--to=anshuman.khandual@arm.com \
--cc=akpm@linux-foundation.org \
--cc=catalin.marinas@arm.com \
--cc=dave.hansen@linux.intel.com \
--cc=devel@driverdev.osuosl.org \
--cc=gregkh@linuxfoundation.org \
--cc=gxt@pku.edu.cn \
--cc=heiko.carstens@de.ibm.com \
--cc=hughd@google.com \
--cc=ley.foon.tan@intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-s390@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=msalter@redhat.com \
--cc=nickhu@andestech.com \
--cc=rspringer@google.com \
--cc=tglx@linutronix.de \
--cc=vbabka@suse.cz \
--cc=ysato@users.sourceforge.jp \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox