From: Jia He <justin.he@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
James Morse <james.morse@arm.com>, Marc Zyngier <maz@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Suzuki Poulose <Suzuki.Poulose@arm.com>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
hejianet@gmail.com, Kaly Xin <Kaly.Xin@arm.com>,
nd@arm.com, Jia He <justin.he@arm.com>
Subject: [PATCH v11 0/4] fix double page fault in cow_user_page for pfn mapping
Date: Wed, 9 Oct 2019 16:42:42 +0800 [thread overview]
Message-ID: <20191009084246.123354-1-justin.he@arm.com> (raw)
When we tested pmdk unit test vmmalloc_fork TEST1 in arm64 guest, there
will be a double page fault in __copy_from_user_inatomic of cow_user_page.
As told by Catalin: "On arm64 without hardware Access Flag, copying from
user will fail because the pte is old and cannot be marked young. So we
always end up with zeroed page after fork() + CoW for pfn mappings. we
don't always have a hardware-managed access flag on arm64."
Changes
v11:
refine cpu_has_hw_af in PATCH 01(Will Deacon, Suzuki)
change the default return value to true in arch_faults_on_old_pte
add PATCH 03 for overriding arch_faults_on_old_pte(false) on x86
v10:
add r-b from Catalin and a-b from Kirill in PATCH 03
remoe Reported-by in PATCH 01
v9: refactor cow_user_page for indention optimization (Catalin)
hold the ptl longer (Catalin)
v8: change cow_user_page's return type (Matthew)
v7: s/pte_spinlock/pte_offset_map_lock (Kirill)
v6: fix error case of returning with spinlock taken (Catalin)
move kmap_atomic to avoid handling kunmap_atomic
v5: handle the case correctly when !pte_same
fix kbuild test failed
v4: introduce cpu_has_hw_af (Suzuki)
bail out if !pte_same (Kirill)
v3: add vmf->ptl lock/unlock (Kirill A. Shutemov)
add arch_faults_on_old_pte (Matthew, Catalin)
v2: remove FAULT_FLAG_WRITE when setting pte access flag (Catalin)
Jia He (4):
arm64: cpufeature: introduce helper cpu_has_hw_af()
arm64: mm: implement arch_faults_on_old_pte() on arm64
x86/mm: implement arch_faults_on_old_pte() stub on x86
mm: fix double page fault on arm64 if PTE_AF is cleared
arch/arm64/include/asm/cpufeature.h | 14 ++++
arch/arm64/include/asm/pgtable.h | 14 ++++
arch/x86/include/asm/pgtable.h | 6 ++
mm/memory.c | 104 ++++++++++++++++++++++++----
4 files changed, 123 insertions(+), 15 deletions(-)
--
2.17.1
next reply other threads:[~2019-10-09 8:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-09 8:42 Jia He [this message]
2019-10-09 8:42 ` [PATCH v11 1/4] arm64: cpufeature: introduce helper cpu_has_hw_af() Jia He
2019-10-10 16:43 ` Catalin Marinas
2019-10-11 1:16 ` Justin He (Arm Technology China)
2019-10-11 10:38 ` Catalin Marinas
2019-10-11 13:51 ` Justin He (Arm Technology China)
2019-10-09 8:42 ` [PATCH v11 2/4] arm64: mm: implement arch_faults_on_old_pte() on arm64 Jia He
2019-10-09 8:42 ` [PATCH v11 3/4] x86/mm: implement arch_faults_on_old_pte() stub on x86 Jia He
2019-10-09 8:42 ` [PATCH v11 4/4] mm: fix double page fault on arm64 if PTE_AF is cleared Jia He
2019-10-10 16:45 ` Catalin Marinas
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=20191009084246.123354-1-justin.he@arm.com \
--to=justin.he@arm.com \
--cc=Kaly.Xin@arm.com \
--cc=Suzuki.Poulose@arm.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=catalin.marinas@arm.com \
--cc=hejianet@gmail.com \
--cc=hpa@zytor.com \
--cc=james.morse@arm.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mark.rutland@arm.com \
--cc=maz@kernel.org \
--cc=nd@arm.com \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
--cc=willy@infradead.org \
--cc=x86@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).