* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: William Kucharski @ 2020-09-20 15:55 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-aio, linux-mips, David Howells, linux-mm, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390, linux-scsi,
x86, Arnd Bergmann, linux-block, Alexander Viro, io-uring,
linux-arm-kernel, Jens Axboe, linux-parisc, netdev, linux-kernel,
linux-security-module, linux-fsdevel, Andrew Morton, linuxppc-dev
In-Reply-To: <20200920151510.GS32101@casper.infradead.org>
I really like that as it’s self-documenting and anyone debugging it can see what is actually being used at a glance.
> On Sep 20, 2020, at 09:15, Matthew Wilcox <willy@infradead.org> wrote:
>
> On Fri, Sep 18, 2020 at 02:45:25PM +0200, Christoph Hellwig wrote:
>> Add a flag to force processing a syscall as a compat syscall. This is
>> required so that in_compat_syscall() works for I/O submitted by io_uring
>> helper threads on behalf of compat syscalls.
>
> Al doesn't like this much, but my suggestion is to introduce two new
> opcodes -- IORING_OP_READV32 and IORING_OP_WRITEV32. The compat code
> can translate IORING_OP_READV to IORING_OP_READV32 and then the core
> code can know what that user pointer is pointing to.
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Al Viro @ 2020-09-20 18:41 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-aio, linux-mips, David Howells, linux-mm, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390, linux-scsi,
x86, Arnd Bergmann, linux-block, io-uring, linux-arm-kernel,
Jens Axboe, linux-parisc, netdev, linux-kernel,
linux-security-module, linux-fsdevel, Andrew Morton, linuxppc-dev
In-Reply-To: <20200920180742.GN3421308@ZenIV.linux.org.uk>
On Sun, Sep 20, 2020 at 07:07:42PM +0100, Al Viro wrote:
> /proc/bus/input/devices (fucked bitmap-to-text representation)
To illustrate the, er, beauty of that stuff:
; cat32 /proc/bus/input/devices >/tmp/a
; cat /proc/bus/input/devices >/tmp/b
; diff -u /tmp/a /tmp/b|grep '^[-+]'
--- /tmp/a 2020-09-20 14:28:43.442560691 -0400
+++ /tmp/b 2020-09-20 14:28:49.018543230 -0400
-B: KEY=1100f 2902000 8380307c f910f001 feffffdf ffefffff ffffffff fffffffe
+B: KEY=1100f02902000 8380307cf910f001 feffffdfffefffff fffffffffffffffe
-B: KEY=70000 0 0 0 0 0 0 0 0
+B: KEY=70000 0 0 0 0
-B: KEY=420 0 70000 0 0 0 0 0 0 0 0
+B: KEY=420 70000 0 0 0 0
-B: KEY=100000 0 0 0
+B: KEY=10000000000000 0
-B: KEY=4000 0 0 0 0
+B: KEY=4000 0 0
-B: KEY=8000 0 0 0 0 0 1100b 800 2 200000 0 0 0 0
+B: KEY=800000000000 0 0 1100b00000800 200200000 0 0
-B: KEY=3e000b 0 0 0 0 0 0 0
+B: KEY=3e000b00000000 0 0 0
-B: KEY=ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff fffffffe
+B: KEY=ffffffffffffffff ffffffffffffffff ffffffffffffffff fffffffffffffffe
;
(cat32 being a 32bit binary of cat)
All the differences are due to homegrown bitmap-to-text conversion.
Note that feeding that into a pipe leaves the recepient with a lovely problem -
you can't go by the width of words (they are not zero-padded) and you can't
go by the number of words either - it varies from device to device.
And there's nothing we can do with that - it's a userland ABI, can't be
changed without breaking stuff. I would prefer to avoid additional examples
like that, TYVM...
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Matthew Wilcox @ 2020-09-20 19:01 UTC (permalink / raw)
To: Al Viro
Cc: linux-aio, linux-mips, David Howells, linux-mm, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390, linux-scsi,
x86, Arnd Bergmann, linux-block, io-uring, linux-arm-kernel,
Jens Axboe, linux-parisc, netdev, linux-kernel,
linux-security-module, linux-fsdevel, Andrew Morton, linuxppc-dev
In-Reply-To: <20200920180742.GN3421308@ZenIV.linux.org.uk>
On Sun, Sep 20, 2020 at 07:07:42PM +0100, Al Viro wrote:
> 2) a few drivers are really fucked in head. They use different
> *DATA* layouts for reads/writes, depending upon the calling process.
> IOW, if you fork/exec a 32bit binary and your stdin is one of those,
> reads from stdin in parent and child will yield different data layouts.
> On the same struct file.
> That's what Christoph worries about (/dev/sg he'd mentioned is
> one of those).
>
> IMO we should simply have that dozen or so of pathological files
> marked with FMODE_SHITTY_ABI; it's not about how they'd been opened -
> it describes the userland ABI provided by those. And it's cast in stone.
>
> Any in_compat_syscall() in ->read()/->write() instances is an ABI
> bug, plain and simple. Some are unfixable for compatibility reasons, but
> any new caller like that should be a big red flag.
So an IOCB_COMPAT flag would let us know whether the caller is expecting
a 32-bit or 64-bit layout? And io_uring could set it based on the
ctx->compat flag.
> Current list of those turds:
> /dev/sg (pointer-chasing, generally insane)
> /sys/firmware/efi/vars/*/raw_var (fucked binary structure)
> /sys/firmware/efi/vars/new_var (fucked binary structure)
> /sys/firmware/efi/vars/del_var (fucked binary structure)
> /dev/uhid (pointer-chasing for one obsolete command)
> /dev/input/event* (timestamps)
> /dev/uinput (timestamps)
> /proc/bus/input/devices (fucked bitmap-to-text representation)
> /sys/class/input/*/capabilities/* (fucked bitmap-to-text representation)
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Al Viro @ 2020-09-20 19:10 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-aio, linux-mips, David Howells, linux-mm, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390, linux-scsi,
x86, Arnd Bergmann, linux-block, io-uring, linux-arm-kernel,
Jens Axboe, linux-parisc, netdev, linux-kernel,
linux-security-module, linux-fsdevel, Andrew Morton, linuxppc-dev
In-Reply-To: <20200920190159.GT32101@casper.infradead.org>
On Sun, Sep 20, 2020 at 08:01:59PM +0100, Matthew Wilcox wrote:
> On Sun, Sep 20, 2020 at 07:07:42PM +0100, Al Viro wrote:
> > 2) a few drivers are really fucked in head. They use different
> > *DATA* layouts for reads/writes, depending upon the calling process.
> > IOW, if you fork/exec a 32bit binary and your stdin is one of those,
> > reads from stdin in parent and child will yield different data layouts.
> > On the same struct file.
> > That's what Christoph worries about (/dev/sg he'd mentioned is
> > one of those).
> >
> > IMO we should simply have that dozen or so of pathological files
> > marked with FMODE_SHITTY_ABI; it's not about how they'd been opened -
> > it describes the userland ABI provided by those. And it's cast in stone.
> >
> > Any in_compat_syscall() in ->read()/->write() instances is an ABI
> > bug, plain and simple. Some are unfixable for compatibility reasons, but
> > any new caller like that should be a big red flag.
>
> So an IOCB_COMPAT flag would let us know whether the caller is expecting
> a 32-bit or 64-bit layout? And io_uring could set it based on the
> ctx->compat flag.
So you want to convert all that crap to a form that would see iocb
(IOW, ->read_iter()/->write_iter())? And, since quite a few are sysfs
attributes, propagate that through sysfs, changing the method signatures
to match that and either modifying fuckloads of instances or introducing
new special methods for the ones that are sensitive to that crap?
IMO it's much saner to mark those and refuse to touch them from io_uring...
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Andy Lutomirski @ 2020-09-20 19:14 UTC (permalink / raw)
To: Al Viro
Cc: linux-aio, open list:MIPS, David Howells, Linux-MM, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390,
Linux SCSI List, X86 ML, Matthew Wilcox, Arnd Bergmann,
linux-block, io-uring, linux-arm-kernel, Jens Axboe, Parisc List,
Network Development, LKML, LSM List, Linux FS Devel,
Andrew Morton, linuxppc-dev
In-Reply-To: <20200920180742.GN3421308@ZenIV.linux.org.uk>
On Sun, Sep 20, 2020 at 11:07 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Sun, Sep 20, 2020 at 04:15:10PM +0100, Matthew Wilcox wrote:
> > On Fri, Sep 18, 2020 at 02:45:25PM +0200, Christoph Hellwig wrote:
> > > Add a flag to force processing a syscall as a compat syscall. This is
> > > required so that in_compat_syscall() works for I/O submitted by io_uring
> > > helper threads on behalf of compat syscalls.
> >
> > Al doesn't like this much, but my suggestion is to introduce two new
> > opcodes -- IORING_OP_READV32 and IORING_OP_WRITEV32. The compat code
> > can translate IORING_OP_READV to IORING_OP_READV32 and then the core
> > code can know what that user pointer is pointing to.
>
> Let's separate two issues:
> 1) compat syscalls want 32bit iovecs. Nothing to do with the
> drivers, dealt with just fine.
> 2) a few drivers are really fucked in head. They use different
> *DATA* layouts for reads/writes, depending upon the calling process.
> IOW, if you fork/exec a 32bit binary and your stdin is one of those,
> reads from stdin in parent and child will yield different data layouts.
> On the same struct file.
> That's what Christoph worries about (/dev/sg he'd mentioned is
> one of those).
>
> IMO we should simply have that dozen or so of pathological files
> marked with FMODE_SHITTY_ABI; it's not about how they'd been opened -
> it describes the userland ABI provided by those. And it's cast in stone.
>
I wonder if this is really quite cast in stone. We could also have
FMODE_SHITTY_COMPAT and set that when a file like this is *opened* in
compat mode. Then that particular struct file would be read and
written using the compat data format. The change would be
user-visible, but the user that would see it would be very strange
indeed.
I don't have a strong opinion as to whether that is better or worse
than denying io_uring access to these things, but at least it moves
the special case out of io_uring.
--Andy
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Matthew Wilcox @ 2020-09-20 19:22 UTC (permalink / raw)
To: Al Viro
Cc: linux-aio, linux-mips, David Howells, linux-mm, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390, linux-scsi,
x86, Arnd Bergmann, linux-block, io-uring, linux-arm-kernel,
Jens Axboe, linux-parisc, netdev, linux-kernel,
linux-security-module, linux-fsdevel, Andrew Morton, linuxppc-dev
In-Reply-To: <20200920191031.GQ3421308@ZenIV.linux.org.uk>
On Sun, Sep 20, 2020 at 08:10:31PM +0100, Al Viro wrote:
> IMO it's much saner to mark those and refuse to touch them from io_uring...
Simpler solution is to remove io_uring from the 32-bit syscall list.
If you're a 32-bit process, you don't get to use io_uring. Would
any real users actually care about that?
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Andy Lutomirski @ 2020-09-20 19:28 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-aio, open list:MIPS, David Howells, Linux-MM, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390,
Linux SCSI List, X86 ML, Arnd Bergmann, linux-block, Al Viro,
io-uring, linux-arm-kernel, Jens Axboe, Parisc List,
Network Development, LKML, LSM List, Linux FS Devel,
Andrew Morton, linuxppc-dev
In-Reply-To: <20200920192259.GU32101@casper.infradead.org>
On Sun, Sep 20, 2020 at 12:23 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Sun, Sep 20, 2020 at 08:10:31PM +0100, Al Viro wrote:
> > IMO it's much saner to mark those and refuse to touch them from io_uring...
>
> Simpler solution is to remove io_uring from the 32-bit syscall list.
> If you're a 32-bit process, you don't get to use io_uring. Would
> any real users actually care about that?
We could go one step farther and declare that we're done adding *any*
new compat syscalls :)
--
Andy Lutomirski
AMA Capital Management, LLC
^ permalink raw reply
* Re: [PATCH] soc: fsl: dpio: remove set but not used 'addr_cena'
From: Krzysztof Kozlowski @ 2020-09-20 20:19 UTC (permalink / raw)
To: Jason Yan
Cc: Roy.Pledge, linux-kernel@vger.kernel.org, youri.querry_1,
Hulk Robot, leoyang.li, linuxppc-dev, linux-arm-kernel
In-Reply-To: <20200910140415.1132266-1-yanaijie@huawei.com>
On Thu, 10 Sep 2020 at 16:57, Jason Yan <yanaijie@huawei.com> wrote:
>
> This addresses the following gcc warning with "make W=1":
>
> drivers/soc/fsl/dpio/qbman-portal.c: In function
> ‘qbman_swp_enqueue_multiple_direct’:
> drivers/soc/fsl/dpio/qbman-portal.c:650:11: warning: variable
> ‘addr_cena’ set but not used [-Wunused-but-set-variable]
> 650 | uint64_t addr_cena;
> | ^~~~~~~~~
>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Jason Yan <yanaijie@huawei.com>
This was already reported:
Reported-by: kernel test robot <lkp@intel.com>
https://lkml.org/lkml/2020/6/12/290
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Best regards,
Krzysztof
> ---
> drivers/soc/fsl/dpio/qbman-portal.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/soc/fsl/dpio/qbman-portal.c b/drivers/soc/fsl/dpio/qbman-portal.c
> index 0ab85bfb116f..659b4a570d5b 100644
> --- a/drivers/soc/fsl/dpio/qbman-portal.c
> +++ b/drivers/soc/fsl/dpio/qbman-portal.c
> @@ -647,7 +647,6 @@ int qbman_swp_enqueue_multiple_direct(struct qbman_swp *s,
> const uint32_t *cl = (uint32_t *)d;
> uint32_t eqcr_ci, eqcr_pi, half_mask, full_mask;
> int i, num_enqueued = 0;
> - uint64_t addr_cena;
>
> spin_lock(&s->access_spinlock);
> half_mask = (s->eqcr.pi_ci_mask>>1);
> @@ -701,7 +700,6 @@ int qbman_swp_enqueue_multiple_direct(struct qbman_swp *s,
>
> /* Flush all the cacheline without load/store in between */
> eqcr_pi = s->eqcr.pi;
> - addr_cena = (size_t)s->addr_cena;
> for (i = 0; i < num_enqueued; i++)
> eqcr_pi++;
> s->eqcr.pi = eqcr_pi & full_mask;
> --
> 2.25.4
>
^ permalink raw reply
* [PATCH] soc: fsl: qbman: Fix return value on success
From: Krzysztof Kozlowski @ 2020-09-20 20:26 UTC (permalink / raw)
To: Li Yang, Roy Pledge, linuxppc-dev, linux-arm-kernel, linux-kernel
Cc: Krzysztof Kozlowski
On error the function was meant to return -ERRNO. This also fixes
compile warning:
drivers/soc/fsl/qbman/bman.c:640:6: warning: variable 'err' set but not used [-Wunused-but-set-variable]
Fixes: 0505d00c8dba ("soc/fsl/qbman: Cleanup buffer pools if BMan was initialized prior to bootup")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
drivers/soc/fsl/qbman/bman.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/soc/fsl/qbman/bman.c b/drivers/soc/fsl/qbman/bman.c
index f4fb527d8301..c5dd026fe889 100644
--- a/drivers/soc/fsl/qbman/bman.c
+++ b/drivers/soc/fsl/qbman/bman.c
@@ -660,7 +660,7 @@ int bm_shutdown_pool(u32 bpid)
}
done:
put_affine_portal();
- return 0;
+ return err;
}
struct gen_pool *bm_bpalloc;
--
2.17.1
^ permalink raw reply related
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Arnd Bergmann @ 2020-09-20 20:49 UTC (permalink / raw)
To: Andy Lutomirski
Cc: linux-aio, open list:MIPS, David Howells, Linux-MM, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390,
Linux SCSI List, X86 ML, Matthew Wilcox, linux-block, Al Viro,
io-uring, linux-arm-kernel, Jens Axboe, Parisc List,
Network Development, LKML, LSM List, Linux FS Devel,
Andrew Morton, linuxppc-dev
In-Reply-To: <CALCETrXVtBkxNJcMxf9myaKT9snHKbCWUenKHGRfp8AOtORBPg@mail.gmail.com>
On Sun, Sep 20, 2020 at 9:28 PM Andy Lutomirski <luto@kernel.org> wrote:
> On Sun, Sep 20, 2020 at 12:23 PM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Sun, Sep 20, 2020 at 08:10:31PM +0100, Al Viro wrote:
> > > IMO it's much saner to mark those and refuse to touch them from io_uring...
> >
> > Simpler solution is to remove io_uring from the 32-bit syscall list.
> > If you're a 32-bit process, you don't get to use io_uring. Would
> > any real users actually care about that?
>
> We could go one step farther and declare that we're done adding *any*
> new compat syscalls :)
Would you also stop adding system calls to native 32-bit systems then?
On memory constrained systems (less than 2GB a.t.m.), there is still a
strong demand for running 32-bit user space, but all of the recent Arm
cores (after Cortex-A55) dropped the ability to run 32-bit kernels, so
that compat mode may eventually become the primary way to run
Linux on cheap embedded systems.
I don't think there is any chance we can realistically take away io_uring
from the 32-bit ABI any more now.
Arnd
^ permalink raw reply
* RE: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: David Laight @ 2020-09-20 21:13 UTC (permalink / raw)
To: 'Arnd Bergmann', Andy Lutomirski
Cc: linux-aio, open list:MIPS, David Howells, Linux-MM,
keyrings@vger.kernel.org, sparclinux, Christoph Hellwig,
linux-arch, linux-s390, Linux SCSI List, X86 ML, Matthew Wilcox,
linux-block, Al Viro, io-uring@vger.kernel.org, linux-arm-kernel,
Jens Axboe, Parisc List, Network Development, LKML, LSM List,
Linux FS Devel, Andrew Morton, linuxppc-dev
In-Reply-To: <CAK8P3a37BRFj_qg61gP2oVrjJzBrZ58y1vggeTk_5n55Ou5U2Q@mail.gmail.com>
From: Arnd Bergmann
> Sent: 20 September 2020 21:49
>
> On Sun, Sep 20, 2020 at 9:28 PM Andy Lutomirski <luto@kernel.org> wrote:
> > On Sun, Sep 20, 2020 at 12:23 PM Matthew Wilcox <willy@infradead.org> wrote:
> > >
> > > On Sun, Sep 20, 2020 at 08:10:31PM +0100, Al Viro wrote:
> > > > IMO it's much saner to mark those and refuse to touch them from io_uring...
> > >
> > > Simpler solution is to remove io_uring from the 32-bit syscall list.
> > > If you're a 32-bit process, you don't get to use io_uring. Would
> > > any real users actually care about that?
> >
> > We could go one step farther and declare that we're done adding *any*
> > new compat syscalls :)
>
> Would you also stop adding system calls to native 32-bit systems then?
>
> On memory constrained systems (less than 2GB a.t.m.), there is still a
> strong demand for running 32-bit user space, but all of the recent Arm
> cores (after Cortex-A55) dropped the ability to run 32-bit kernels, so
> that compat mode may eventually become the primary way to run
> Linux on cheap embedded systems.
>
> I don't think there is any chance we can realistically take away io_uring
> from the 32-bit ABI any more now.
Can't it just run requests from 32bit apps in a kernel thread that has
the 'in_compat_syscall' flag set?
Not that i recall seeing the code where it saves the 'compat' nature
of any requests.
It is already completely f*cked if you try to pass the command ring
to a child process - it uses the wrong 'mm'.
I suspect there are some really horrid security holes in that area.
David.
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Al Viro @ 2020-09-20 21:42 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-aio, linux-mips, David Howells, linux-mm, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390, linux-scsi,
x86, Arnd Bergmann, linux-block, io-uring, linux-arm-kernel,
Jens Axboe, linux-parisc, netdev, linux-kernel,
linux-security-module, linux-fsdevel, Andrew Morton, linuxppc-dev
In-Reply-To: <20200920192259.GU32101@casper.infradead.org>
On Sun, Sep 20, 2020 at 08:22:59PM +0100, Matthew Wilcox wrote:
> On Sun, Sep 20, 2020 at 08:10:31PM +0100, Al Viro wrote:
> > IMO it's much saner to mark those and refuse to touch them from io_uring...
>
> Simpler solution is to remove io_uring from the 32-bit syscall list.
> If you're a 32-bit process, you don't get to use io_uring. Would
> any real users actually care about that?
What for? I mean, is there any reason to try and keep those bugs as
first-class citizens? IDGI... Yes, we have several special files
(out of thousands) that have read()/write() user-visible semantics
broken wrt 32bit/64bit. And we have to keep them working that way
for existing syscalls. Why would we want to pretend that their
behaviour is normal and isn't an ABI bug, not to be repeated for
anything new?
^ permalink raw reply
* [PATCH] fsl: imx-audmix : Use devm_kcalloc() instead of devm_kzalloc()
From: Xu Wang @ 2020-09-21 1:59 UTC (permalink / raw)
To: timur, nicoleotsuka, Xiubo.Lee, festevam, shengjiu.wang,
lgirdwood, broonie, perex, tiwai, shawnguo, s.hauer, kernel,
linux-imx, alsa-devel, linuxppc-dev, linux-arm-kernel
Cc: linux-kernel, Xu Wang
A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "devm_kcalloc".
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
---
sound/soc/fsl/imx-audmix.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/sound/soc/fsl/imx-audmix.c b/sound/soc/fsl/imx-audmix.c
index 202fb8950078..cbdc0a2c09c5 100644
--- a/sound/soc/fsl/imx-audmix.c
+++ b/sound/soc/fsl/imx-audmix.c
@@ -185,20 +185,20 @@ static int imx_audmix_probe(struct platform_device *pdev)
return -ENOMEM;
priv->num_dai = 2 * num_dai;
- priv->dai = devm_kzalloc(&pdev->dev, priv->num_dai *
+ priv->dai = devm_kcalloc(&pdev->dev, priv->num_dai,
sizeof(struct snd_soc_dai_link), GFP_KERNEL);
if (!priv->dai)
return -ENOMEM;
priv->num_dai_conf = num_dai;
- priv->dai_conf = devm_kzalloc(&pdev->dev, priv->num_dai_conf *
+ priv->dai_conf = devm_kcalloc(&pdev->dev, priv->num_dai_conf,
sizeof(struct snd_soc_codec_conf),
GFP_KERNEL);
if (!priv->dai_conf)
return -ENOMEM;
priv->num_dapm_routes = 3 * num_dai;
- priv->dapm_routes = devm_kzalloc(&pdev->dev, priv->num_dapm_routes *
+ priv->dapm_routes = devm_kcalloc(&pdev->dev, priv->num_dapm_routes,
sizeof(struct snd_soc_dapm_route),
GFP_KERNEL);
if (!priv->dapm_routes)
@@ -208,7 +208,7 @@ static int imx_audmix_probe(struct platform_device *pdev)
struct snd_soc_dai_link_component *dlc;
/* for CPU/Codec/Platform x 2 */
- dlc = devm_kzalloc(&pdev->dev, 6 * sizeof(*dlc), GFP_KERNEL);
+ dlc = devm_kcalloc(&pdev->dev, 6, sizeof(*dlc), GFP_KERNEL);
if (!dlc) {
dev_err(&pdev->dev, "failed to allocate dai_link\n");
return -ENOMEM;
--
2.17.1
^ permalink raw reply related
* Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Christoph Hellwig @ 2020-09-21 4:28 UTC (permalink / raw)
To: Andy Lutomirski
Cc: linux-aio, open list:MIPS, David Howells, Linux-MM, keyrings,
sparclinux, Christoph Hellwig, linux-arch, linux-s390,
Linux SCSI List, X86 ML, Matthew Wilcox, Arnd Bergmann,
linux-block, Al Viro, io-uring, linux-arm-kernel, Jens Axboe,
Parisc List, Network Development, LKML, LSM List, Linux FS Devel,
Andrew Morton, linuxppc-dev
In-Reply-To: <CALCETrWHW4wHG+Z-mxsY-kvjSi+S6gRUQ+LHd9syPcm5bhi3cw@mail.gmail.com>
On Sun, Sep 20, 2020 at 12:14:49PM -0700, Andy Lutomirski wrote:
> I wonder if this is really quite cast in stone. We could also have
> FMODE_SHITTY_COMPAT and set that when a file like this is *opened* in
> compat mode. Then that particular struct file would be read and
> written using the compat data format. The change would be
> user-visible, but the user that would see it would be very strange
> indeed.
>
> I don't have a strong opinion as to whether that is better or worse
> than denying io_uring access to these things, but at least it moves
> the special case out of io_uring.
open could have happened through an io_uring thread a well, so I don't
see how this would do anything but move the problem to a different
place.
>
> --Andy
---end quoted text---
^ permalink raw reply
* Re: let import_iovec deal with compat_iovecs as well
From: 'Christoph Hellwig' @ 2020-09-21 4:41 UTC (permalink / raw)
To: David Laight
Cc: linux-aio@kvack.org, linux-mips@vger.kernel.org, David Howells,
linux-mm@kvack.org, keyrings@vger.kernel.org,
sparclinux@vger.kernel.org, 'Christoph Hellwig',
linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
linux-scsi@vger.kernel.org, x86@kernel.org, Arnd Bergmann,
linux-block@vger.kernel.org, Alexander Viro,
io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
Jens Axboe, linux-parisc@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org, Andrew Morton,
linuxppc-dev@lists.ozlabs.org
In-Reply-To: <2c7bf42ee4314484ae0177280cd8f5f3@AcuMS.aculab.com>
On Sat, Sep 19, 2020 at 02:24:10PM +0000, David Laight wrote:
> I thought about that change while writing my import_iovec() => iovec_import()
> patch - and thought that the io_uring code would (as usual) cause grief.
>
> Christoph - did you see those patches?
No.
^ permalink raw reply
* Re: [patch RFC 01/15] mm/highmem: Un-EXPORT __kmap_atomic_idx()
From: Christoph Hellwig @ 2020-09-21 6:23 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Juri Lelli, Peter Zijlstra, Sebastian Andrzej Siewior,
Joonas Lahtinen, dri-devel, linux-mips, Ben Segall, Max Filippov,
Guo Ren, sparclinux, Vincent Chen, Will Deacon, Ard Biesheuvel,
linux-arch, Vincent Guittot, Herbert Xu, x86, Russell King,
linux-csky, David Airlie, Mel Gorman, linux-snps-arc,
linux-xtensa, Paul McKenney, intel-gfx, linuxppc-dev,
Steven Rostedt, Linus Torvalds, Jani Nikula, Rodrigo Vivi,
Dietmar Eggemann, Linux ARM, Chris Zankel, Michal Simek,
Thomas Bogendoerfer, Nick Hu, Linux-MM, Vineet Gupta, LKML,
Arnd Bergmann, Daniel Vetter, Paul Mackerras, Andrew Morton,
Daniel Bristot de Oliveira, David S. Miller, Greentime Hu
In-Reply-To: <20200919092615.879315697@linutronix.de>
On Sat, Sep 19, 2020 at 11:17:52AM +0200, Thomas Gleixner wrote:
> Nothing in modules can use that.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply
* Re: [patch RFC 02/15] highmem: Provide generic variant of kmap_atomic*
From: Christoph Hellwig @ 2020-09-21 6:28 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Juri Lelli, Peter Zijlstra, Sebastian Andrzej Siewior,
Joonas Lahtinen, dri-devel, linux-mips, Ben Segall, Max Filippov,
Guo Ren, sparclinux, Vincent Chen, Will Deacon, Ard Biesheuvel,
linux-arch, Vincent Guittot, Herbert Xu, x86, Russell King,
linux-csky, David Airlie, Mel Gorman, linux-snps-arc,
linux-xtensa, Paul McKenney, intel-gfx, linuxppc-dev,
Steven Rostedt, Linus Torvalds, Jani Nikula, Rodrigo Vivi,
Dietmar Eggemann, Linux ARM, Chris Zankel, Michal Simek,
Thomas Bogendoerfer, Nick Hu, Linux-MM, Vineet Gupta, LKML,
Arnd Bergmann, Daniel Vetter, Paul Mackerras, Andrew Morton,
Daniel Bristot de Oliveira, David S. Miller, Greentime Hu
In-Reply-To: <20200919092615.990731525@linutronix.de>
> +# ifndef ARCH_NEEDS_KMAP_HIGH_GET
> +static inline void *arch_kmap_temporary_high_get(struct page *page)
> +{
> + return NULL;
> +}
> +# endif
Turn this into a macro and use #ifndef on the symbol name?
> +static inline void __kunmap_atomic(void *addr)
> +{
> + kumap_atomic_indexed(addr);
> +}
> +
> +
> +#endif /* CONFIG_KMAP_ATOMIC_GENERIC */
Stange double empty line above the endif.
> -#define kunmap_atomic(addr) \
> -do { \
> - BUILD_BUG_ON(__same_type((addr), struct page *)); \
> - kunmap_atomic_high(addr); \
> - pagefault_enable(); \
> - preempt_enable(); \
> -} while (0)
> -
> +#define kunmap_atomic(addr) \
> + do { \
> + BUILD_BUG_ON(__same_type((addr), struct page *)); \
> + __kunmap_atomic(addr); \
> + preempt_enable(); \
> + } while (0)
Why the strange re-indent to a form that is much less common and less
readable?
> +void *kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
> +{
> + pagefault_disable();
> + return __kmap_atomic_pfn_prot(pfn, prot);
> +}
> +EXPORT_SYMBOL(kmap_atomic_pfn_prot);
The existing kmap_atomic_pfn & co implementation is EXPORT_SYMBOL_GPL,
and this stuff should preferably stay that way.
^ permalink raw reply
* [PATCH V2] powerpc/perf: Exclude pmc5/6 from the irrelevant PMU group constraints
From: Athira Rajeev @ 2020-09-21 7:10 UTC (permalink / raw)
To: mpe; +Cc: maddy, linuxppc-dev
PMU counter support functions enforces event constraints for group of
events to check if all events in a group can be monitored. Incase of
event codes using PMC5 and PMC6 ( 500fa and 600f4 respectively ),
not all constraints are applicable, say the threshold or sample bits.
But current code includes pmc5 and pmc6 in some group constraints (like
IC_DC Qualifier bits) which is actually not applicable and hence results
in those events not getting counted when scheduled along with group of
other events. Patch fixes this by excluding PMC5/6 from constraints
which are not relevant for it.
Fixes: 7ffd948 ("powerpc/perf: factor out power8 pmu functions")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
---
Changes in v2:
- Added a block comment in the fix path explaining
why the change is needed.
arch/powerpc/perf/isa207-common.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
index 964437a..12153da 100644
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -288,6 +288,15 @@ int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp)
mask |= CNST_PMC_MASK(pmc);
value |= CNST_PMC_VAL(pmc);
+
+ /*
+ * PMC5 and PMC6 are used to count cycles and instructions
+ * and these doesnot support most of the constraint bits.
+ * Add a check to exclude PMC5/6 from most of the constraints
+ * except for ebb/bhrb.
+ */
+ if (pmc >= 5)
+ goto ebb_bhrb;
}
if (pmc <= 4) {
@@ -357,6 +366,7 @@ int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp)
}
}
+ebb_bhrb:
if (!pmc && ebb)
/* EBB events must specify the PMC */
return -1;
--
1.8.3.1
^ permalink raw reply related
* Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
From: Thomas Gleixner @ 2020-09-21 7:39 UTC (permalink / raw)
To: Linus Torvalds
Cc: Juri Lelli, Peter Zijlstra, Sebastian Andrzej Siewior,
Joonas Lahtinen, dri-devel, linux-mips, Ben Segall, Max Filippov,
Guo Ren, linux-sparc, Vincent Chen, Will Deacon, Ard Biesheuvel,
linux-arch, Vincent Guittot, Herbert Xu, the arch/x86 maintainers,
Russell King, linux-csky, David Airlie, Mel Gorman,
open list:SYNOPSYS ARC ARCHITECTURE, linux-xtensa, Paul McKenney,
intel-gfx, linuxppc-dev, Steven Rostedt, Jani Nikula,
Rodrigo Vivi, Dietmar Eggemann, Linux ARM, Chris Zankel,
Michal Simek, Thomas Bogendoerfer, Nick Hu, Linux-MM,
Vineet Gupta, LKML, Arnd Bergmann, Daniel Vetter, Paul Mackerras,
Andrew Morton, Daniel Bristot de Oliveira, David S. Miller,
Greentime Hu
In-Reply-To: <CAHk-=wgF-upZVpqJWK=TK7MS9H-Rp1ZxGfOG+dDW=JThtxAzVQ@mail.gmail.com>
On Sun, Sep 20 2020 at 10:42, Linus Torvalds wrote:
> On Sun, Sep 20, 2020 at 10:40 AM Thomas Gleixner <tglx@linutronix.de> wrote:
>>
>> I think the more obvious solution is to split the whole exercise:
>>
>> schedule()
>> prepare_switch()
>> unmap()
>>
>> switch_to()
>>
>> finish_switch()
>> map()
>
> Yeah, that looks much easier to explain. Ack.
So far so good, but Peter Z. just pointed out to me that I completely
missed the fact that this cannot work.
If a task is migrated to a different CPU then the mapping address will
change which will explode in colourful ways.
On RT kernels this works because we ping the task to the CPU via
migrate_disable(). On a !RT kernel migrate_disable() maps to
preempt_disable() which brings us back to square one.
/me goes back to the drawing board.
Thanks,
tglx
^ permalink raw reply
* Re: [PATCH v2 1/4] selftests/seccomp: Record syscall during ptrace entry
From: Christian Brauner @ 2020-09-21 7:43 UTC (permalink / raw)
To: Kees Cook
Cc: Thadeu Lima de Souza Cascardo, Will Drewry, linux-xtensa,
linux-kernel, Andy Lutomirski, Max Filippov, linux-arm-kernel,
linux-kselftest, linux-mips, linuxppc-dev, Christian Brauner
In-Reply-To: <20200919080637.259478-2-keescook@chromium.org>
On Sat, Sep 19, 2020 at 01:06:34AM -0700, Kees Cook wrote:
> In preparation for performing actions during ptrace syscall exit, save
> the syscall number during ptrace syscall entry. Some architectures do
> no have the syscall number available during ptrace syscall exit.
>
> Suggested-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
> Link: https://lore.kernel.org/linux-kselftest/20200911181012.171027-1-cascardo@canonical.com/
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> tools/testing/selftests/seccomp/seccomp_bpf.c | 40 +++++++++++++------
> 1 file changed, 27 insertions(+), 13 deletions(-)
>
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index bc0fb463c709..c0311b4c736b 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -1949,12 +1949,19 @@ void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
>
> }
>
> +FIXTURE(TRACE_syscall) {
> + struct sock_fprog prog;
> + pid_t tracer, mytid, mypid, parent;
> + long syscall_nr;
> +};
> +
> void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
> int status, void *args)
> {
> - int ret, nr;
> + int ret;
> unsigned long msg;
> static bool entry;
> + FIXTURE_DATA(TRACE_syscall) *self = args;
>
> /*
> * The traditional way to tell PTRACE_SYSCALL entry/exit
> @@ -1968,24 +1975,31 @@ void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
> EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
> : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
>
> - if (!entry)
> + /*
> + * Some architectures only support setting return values during
> + * syscall exit under ptrace, and on exit the syscall number may
> + * no longer be available. Therefore, save the initial sycall
s/sycall/syscall/
Otherwise looks good. Thanks!
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
> + * number here, so it can be examined during both entry and exit
> + * phases.
> + */
> + if (entry)
> + self->syscall_nr = get_syscall(_metadata, tracee);
> + else
> return;
>
> - nr = get_syscall(_metadata, tracee);
> -
> - if (nr == __NR_getpid)
> + switch (self->syscall_nr) {
> + case __NR_getpid:
> change_syscall(_metadata, tracee, __NR_getppid, 0);
> - if (nr == __NR_gettid)
> + break;
> + case __NR_gettid:
> change_syscall(_metadata, tracee, -1, 45000);
> - if (nr == __NR_openat)
> + break;
> + case __NR_openat:
> change_syscall(_metadata, tracee, -1, -ESRCH);
> + break;
> + }
> }
>
> -FIXTURE(TRACE_syscall) {
> - struct sock_fprog prog;
> - pid_t tracer, mytid, mypid, parent;
> -};
> -
> FIXTURE_VARIANT(TRACE_syscall) {
> /*
> * All of the SECCOMP_RET_TRACE behaviors can be tested with either
> @@ -2044,7 +2058,7 @@ FIXTURE_SETUP(TRACE_syscall)
> self->tracer = setup_trace_fixture(_metadata,
> variant->use_ptrace ? tracer_ptrace
> : tracer_seccomp,
> - NULL, variant->use_ptrace);
> + self, variant->use_ptrace);
>
> ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
> ASSERT_EQ(0, ret);
> --
> 2.25.1
>
^ permalink raw reply
* Re: [PATCH v2 2/4] selftests/seccomp: Allow syscall nr and ret value to be set separately
From: Christian Brauner @ 2020-09-21 7:50 UTC (permalink / raw)
To: Kees Cook
Cc: Thadeu Lima de Souza Cascardo, Will Drewry, linux-xtensa,
linux-kernel, Andy Lutomirski, Max Filippov, linux-arm-kernel,
linux-kselftest, linux-mips, linuxppc-dev, Christian Brauner
In-Reply-To: <20200919080637.259478-3-keescook@chromium.org>
On Sat, Sep 19, 2020 at 01:06:35AM -0700, Kees Cook wrote:
> In preparation for setting syscall nr and ret values separately, refactor
> the helpers to take a pointer to a value, so that a NULL can indicate
> "do not change this respective value". This is done to keep the regset
> read/write happening once and in one code path.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
Looks good!
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
^ permalink raw reply
* Re: [PATCH v2 3/4] selftests/seccomp: powerpc: Set syscall return during ptrace syscall exit
From: Christian Brauner @ 2020-09-21 7:53 UTC (permalink / raw)
To: Kees Cook
Cc: Thadeu Lima de Souza Cascardo, Will Drewry, linux-xtensa,
linux-kernel, Andy Lutomirski, Max Filippov, linux-arm-kernel,
linux-kselftest, linux-mips, linuxppc-dev, Christian Brauner
In-Reply-To: <20200919080637.259478-4-keescook@chromium.org>
On Sat, Sep 19, 2020 at 01:06:36AM -0700, Kees Cook wrote:
> Some archs (like powerpc) only support changing the return code during
> syscall exit when ptrace is used. Test entry vs exit phases for which
> portions of the syscall number and return values need to be set at which
> different phases. For non-powerpc, all changes are made during ptrace
> syscall entry, as before. For powerpc, the syscall number is changed at
> ptrace syscall entry and the syscall return value is changed on ptrace
> syscall exit.
>
> Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
> Suggested-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
> Link: https://lore.kernel.org/linux-kselftest/20200911181012.171027-1-cascardo@canonical.com/
> Fixes: 58d0a862f573 ("seccomp: add tests for ptrace hole")
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
Looks good!
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
^ permalink raw reply
* Re: [PATCH v2 4/4] selftests/clone3: Avoid OS-defined clone_args
From: Christian Brauner @ 2020-09-21 7:54 UTC (permalink / raw)
To: Kees Cook
Cc: Thadeu Lima de Souza Cascardo, Will Drewry, linux-xtensa,
linux-kernel, Andy Lutomirski, Max Filippov, linux-arm-kernel,
linux-kselftest, linux-mips, linuxppc-dev, Christian Brauner
In-Reply-To: <20200919080637.259478-5-keescook@chromium.org>
On Sat, Sep 19, 2020 at 01:06:37AM -0700, Kees Cook wrote:
> As the UAPI headers start to appear in distros, we need to avoid outdated
> versions of struct clone_args to be able to test modern features;
> rename to "struct __clone_args". Additionally update the struct size
> macro names to match UAPI names.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
Looks good, thanks!
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
^ permalink raw reply
* Re: [PATCH AUTOSEL 5.4 101/330] powerpc/powernv/ioda: Fix ref count for devices with their own PE
From: Frederic Barrat @ 2020-09-21 7:58 UTC (permalink / raw)
To: Sasha Levin; +Cc: linuxppc-dev, linux-kernel, stable, Andrew Donnellan
In-Reply-To: <20200919181029.GI2431@sasha-vm>
Le 19/09/2020 à 20:10, Sasha Levin a écrit :
> On Fri, Sep 18, 2020 at 08:35:06AM +0200, Frederic Barrat wrote:
>>
>>
>> Le 18/09/2020 à 03:57, Sasha Levin a écrit :
>>> From: Frederic Barrat <fbarrat@linux.ibm.com>
>>>
>>> [ Upstream commit 05dd7da76986937fb288b4213b1fa10dbe0d1b33 ]
>>>
>>
>> This patch is not desirable for stable, for 5.4 and 4.19 (it was
>> already flagged by autosel back in April. Not sure why it's showing
>> again now)
>
> Hey Fred,
>
> This was a bit of a "lie", it wasn't a run of AUTOSEL, but rather an
> audit of patches that went into distro/vendor trees but not into the
> upstream stable trees.
>
> I can see that this patch was pulled into Ubuntu's 5.4 tree, is it not
> needed in the upstream stable tree?
That patch in itself is useless (it replaces a ref counter leak by
another one). It was part of a longer series that we backported to
Ubuntu's 5.4 tree.
So it's really not needed on the stable trees. It likely wouldn't hurt
or break anything, but there's really no point.
Fred
^ permalink raw reply
* [PATCH V2] Doc: admin-guide: Add entry for kvm_cma_resv_ratio kernel param
From: sathnaga @ 2020-09-21 9:02 UTC (permalink / raw)
To: linux-doc
Cc: Jonathan Corbet, Randy Dunlap, linux-kernel, kvm-ppc,
Paul Mackerras, Satheesh Rajendran, linuxppc-dev
From: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Add document entry for kvm_cma_resv_ratio kernel param which
is used to alter the KVM contiguous memory allocation percentage
for hash pagetable allocation used by hash mode PowerPC KVM guests.
Cc: linux-kernel@vger.kernel.org
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
---
V2:
Addressed review comments from Randy.
V1: https://lkml.org/lkml/2020/9/16/72
---
Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a1068742a6df..932ed45740c9 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2258,6 +2258,14 @@
[KVM,ARM] Allow use of GICv4 for direct injection of
LPIs.
+ kvm_cma_resv_ratio=n [PPC]
+ Reserves given percentage from system memory area for
+ contiguous memory allocation for KVM hash pagetable
+ allocation.
+ By default it reserves 5% of total system memory.
+ Format: <integer>
+ Default: 5
+
kvm-intel.ept= [KVM,Intel] Disable extended page tables
(virtualized MMU) support on capable Intel chips.
Default is 1 (enabled)
--
2.26.2
^ permalink raw reply related
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