From: Dmitry Safonov <dima@arista.com>
To: linux-kernel@vger.kernel.org
Cc: Dmitry Safonov <dima@arista.com>, Adrian Reber <adrian@lisas.de>,
Andrei Vagin <avagin@openvz.org>, Andrei Vagin <avagin@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Andy Tucker <agtucker@google.com>, Arnd Bergmann <arnd@arndb.de>,
Christian Brauner <christian.brauner@ubuntu.com>,
Cyrill Gorcunov <gorcunov@openvz.org>,
Dmitry Safonov <0x7f454c46@gmail.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Jeff Dike <jdike@addtoit.com>, Oleg Nesterov <oleg@redhat.com>,
Pavel Emelyanov <xemul@virtuozzo.com>,
Shuah Khan <shuah@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
containers@lists.linux-foundation.org, criu@openvz.org,
linux-api@vger.kernel.org, x86@kernel.org
Subject: [PATCH 32/32] x86/vdso: Restrict splitting VVAR VMA
Date: Wed, 6 Feb 2019 00:11:06 +0000 [thread overview]
Message-ID: <20190206001107.16488-33-dima@arista.com> (raw)
In-Reply-To: <20190206001107.16488-1-dima@arista.com>
Although, time namespace can work with VVAR VMA split, it seems worth
to forbid splitting VVAR resulting in stricter ABI and reducing amount
of corner-cases to consider while working further on VDSO.
I don't think there is any use-case for partial mremap() of vvar,
but it there is - this patch can be easily dropped.
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/entry/vdso/vma.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 52c1e4c24455..dc1fca4d935a 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -87,6 +87,18 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
return 0;
}
+static int vvar_mremap(const struct vm_special_mapping *sm,
+ struct vm_area_struct *new_vma)
+{
+ unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
+ const struct vdso_image *image = current->mm->context.vdso_image;
+
+ if (new_size != -image->sym_vvar_start)
+ return -EINVAL;
+
+ return 0;
+}
+
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
@@ -149,6 +161,7 @@ static const struct vm_special_mapping vdso_mapping = {
static const struct vm_special_mapping vvar_mapping = {
.name = "[vvar]",
.fault = vvar_fault,
+ .mremap = vvar_mremap,
};
#ifdef CONFIG_TIME_NS
--
2.20.1
prev parent reply other threads:[~2019-02-06 0:12 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 0:10 [PATCH 00/32] kernel: Introduce Time Namespace Dmitry Safonov
2019-02-06 0:10 ` [PATCH 01/32] ns: " Dmitry Safonov
2019-02-06 0:10 ` [PATCH 02/32] timens: Add timens_offsets Dmitry Safonov
2019-02-06 0:10 ` [PATCH 03/32] timens: Introduce CLOCK_MONOTONIC offsets Dmitry Safonov
2019-02-07 21:40 ` Thomas Gleixner
2019-02-08 9:02 ` Andrei Vagin
2019-02-08 9:46 ` Thomas Gleixner
2019-02-06 0:10 ` [PATCH 04/32] timens: Introduce CLOCK_BOOTTIME offset Dmitry Safonov
2019-02-06 0:10 ` [PATCH 05/32] timerfd/timens: Take into account ns clock offsets Dmitry Safonov
2019-02-06 8:52 ` Cyrill Gorcunov
2019-02-06 8:55 ` Cyrill Gorcunov
2019-02-07 6:38 ` Andrei Vagin
2019-02-06 0:10 ` [PATCH 06/32] posix-timers/timens: Take into account " Dmitry Safonov
2019-02-06 0:10 ` [PATCH 07/32] timens/kernel: Take into account timens clock offsets in clock_nanosleep Dmitry Safonov
2019-02-08 7:56 ` Thomas Gleixner
2019-02-06 0:10 ` [PATCH 08/32] timens: Shift /proc/uptime Dmitry Safonov
2019-02-06 0:10 ` [PATCH 09/32] x86/vdso2c: Correct err messages on file opening Dmitry Safonov
2019-02-06 0:10 ` [PATCH 10/32] x86/vdso2c: Convert iterator to unsigned Dmitry Safonov
2019-02-06 0:10 ` [PATCH 11/32] x86/vdso/Makefile: Add vobjs32 Dmitry Safonov
2019-02-06 0:10 ` [PATCH 12/32] x86/vdso/timens: Add offsets page in vvar Dmitry Safonov
2019-02-06 0:10 ` [PATCH 13/32] x86/vdso: Build timens .so(s) Dmitry Safonov
2019-02-06 0:10 ` [PATCH 14/32] x86/VDSO: Build VDSO with -ffunction-sections Dmitry Safonov
2019-02-06 0:10 ` [PATCH 15/32] x86/vdso2c: Optionally produce linker script for vdso entries Dmitry Safonov
2019-02-06 0:10 ` [PATCH 16/32] x86/vdso: Generate vdso{,32}-timens.lds Dmitry Safonov
2019-02-07 8:31 ` Rasmus Villemoes
2019-02-07 16:11 ` Dmitry Safonov
2019-02-08 9:57 ` Thomas Gleixner
2019-02-08 15:18 ` Dmitry Safonov
2019-03-27 18:00 ` Andrei Vagin
2019-03-27 18:06 ` [PATCH RFC] x86/asm: Introduce static_retcall(s) Andrei Vagin
2019-03-27 18:06 ` [PATCH RFC] vdso: introduce timens_static_branch Andrei Vagin
2019-02-06 0:10 ` [PATCH 17/32] x86/vdso2c: Sort vdso entries by addresses for linker script Dmitry Safonov
2019-02-06 0:10 ` [PATCH 18/32] x86/vdso.lds: Align !timens (host's) vdso.so entries Dmitry Safonov
2019-02-06 0:10 ` [PATCH 19/32] x86/vdso2c: Align LOCAL symbols between vdso{-timens,}.so Dmitry Safonov
2019-02-06 0:10 ` [PATCH 20/32] x86/vdso: Initialize timens 64-bit vdso Dmitry Safonov
2019-02-06 0:10 ` [PATCH 21/32] x86/vdso: Switch image on setns()/unshare()/clone() Dmitry Safonov
2019-02-06 0:10 ` [PATCH 22/32] timens: Add align for timens_offsets Dmitry Safonov
2019-02-06 0:10 ` [PATCH 23/32] timens/fs/proc: Introduce /proc/pid/timens_offsets Dmitry Safonov
2019-02-06 0:10 ` [PATCH 24/32] selftest/timens: Add Time Namespace test for supported clocks Dmitry Safonov
2019-02-06 0:10 ` [PATCH 25/32] selftest/timens: Add a test for timerfd Dmitry Safonov
2019-02-06 0:11 ` [PATCH 26/32] selftest/timens: Add a test for clock_nanosleep() Dmitry Safonov
2019-02-06 0:11 ` [PATCH 27/32] selftest/timens: Add procfs selftest Dmitry Safonov
2019-02-06 0:11 ` [PATCH 28/32] selftest/timens: Add timer offsets test Dmitry Safonov
2019-02-06 0:11 ` [PATCH 29/32] selftests: Add a simple perf test for clock_gettime() Dmitry Safonov
2019-02-06 0:11 ` [PATCH 30/32] selftest/timens: Check that a right vdso is mapped after fork and exec Dmitry Safonov
2019-02-06 0:11 ` [PATCH 31/32] x86/vdso: Align VDSO functions by CPU L1 cache line Dmitry Safonov
2019-02-06 0:11 ` Dmitry Safonov [this message]
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