* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-25 14:47 ` [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere Arnd Bergmann
@ 2019-03-25 17:37 ` Paul Burton
2019-03-26 8:40 ` Arnd Bergmann
2019-03-30 9:42 ` Heiko Carstens
` (3 subsequent siblings)
4 siblings, 1 reply; 16+ messages in thread
From: Paul Burton @ 2019-03-25 17:37 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Andrew Morton, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Russell King, Catalin Marinas, Will Deacon, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Martin Schwidefsky, Heiko Carstens, Rich Felker,
David S . Miller, Max Filippov, Firoz Khan, linux-alpha,
linux-kernel, linux-arm-kernel, linux-ia64, linux-m68k,
linux-mips, linux-parisc, linuxppc-dev, linux-s390, linux-sh,
sparclinux
Hi Arnd,
On Mon, Mar 25, 2019 at 03:47:37PM +0100, Arnd Bergmann wrote:
> Add the io_uring and pidfd_send_signal system calls to all architectures.
>
> These system calls are designed to handle both native and compat tasks,
> so all entries are the same across architectures, only arm-compat and
> the generic tale still use an old format.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>%
> diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
> index c85502e67b44..c4a49f7d57bb 100644
> --- a/arch/mips/kernel/syscalls/syscall_n64.tbl
> +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
> @@ -338,3 +338,7 @@
> 327 n64 rseq sys_rseq
> 328 n64 io_pgetevents sys_io_pgetevents
> # 329 through 423 are reserved to sync up with other architectures
> +424 common pidfd_send_signal sys_pidfd_send_signal
> +425 common io_uring_setup sys_io_uring_setup
> +426 common io_uring_enter sys_io_uring_enter
> +427 common io_uring_register sys_io_uring_register
Shouldn't these declare the ABI as "n64"?
I don't see anywhere that it would actually change the generated code,
but a comment at the top of the file says that every entry should use
"n64" and so far they all do. Did you have something else in mind here?
Thanks,
Paul
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-25 17:37 ` Paul Burton
@ 2019-03-26 8:40 ` Arnd Bergmann
0 siblings, 0 replies; 16+ messages in thread
From: Arnd Bergmann @ 2019-03-26 8:40 UTC (permalink / raw)
To: Paul Burton
Cc: Andrew Morton, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Russell King, Catalin Marinas, Will Deacon, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Martin Schwidefsky, Heiko Carstens, Rich Felker,
David S . Miller, Max Filippov, Firoz Khan, linux-alpha,
linux-kernel, linux-arm-kernel, linux-ia64, linux-m68k,
linux-mips, linux-parisc, linuxppc-dev, linux-s390, linux-sh,
sparclinux
On Mon, Mar 25, 2019 at 6:37 PM Paul Burton <paul.burton@mips.com> wrote:
> On Mon, Mar 25, 2019 at 03:47:37PM +0100, Arnd Bergmann wrote:
> > Add the io_uring and pidfd_send_signal system calls to all architectures.
> >
> > These system calls are designed to handle both native and compat tasks,
> > so all entries are the same across architectures, only arm-compat and
> > the generic tale still use an old format.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> >%
> > diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
> > index c85502e67b44..c4a49f7d57bb 100644
> > --- a/arch/mips/kernel/syscalls/syscall_n64.tbl
> > +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
> > @@ -338,3 +338,7 @@
> > 327 n64 rseq sys_rseq
> > 328 n64 io_pgetevents sys_io_pgetevents
> > # 329 through 423 are reserved to sync up with other architectures
> > +424 common pidfd_send_signal sys_pidfd_send_signal
> > +425 common io_uring_setup sys_io_uring_setup
> > +426 common io_uring_enter sys_io_uring_enter
> > +427 common io_uring_register sys_io_uring_register
>
> Shouldn't these declare the ABI as "n64"?
>
> I don't see anywhere that it would actually change the generated code,
> but a comment at the top of the file says that every entry should use
> "n64" and so far they all do. Did you have something else in mind here?
You are right, the use of 'common' here is unintentional but harmless,
and I should have used 'n64' here.
We may decide to do things differently in the future, i.e. we could
have just a single global file for newly added system calls once
it turns out that the tables are consistent across all architectures,
but I'd probably go on with the separate identical entries for a bit
before changing that.
Arnd
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-25 14:47 ` [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere Arnd Bergmann
2019-03-25 17:37 ` Paul Burton
@ 2019-03-30 9:42 ` Heiko Carstens
2019-03-31 9:47 ` Michael Ellerman
` (2 subsequent siblings)
4 siblings, 0 replies; 16+ messages in thread
From: Heiko Carstens @ 2019-03-30 9:42 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Andrew Morton, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Russell King, Catalin Marinas, Will Deacon, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
Paul Burton, James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Martin Schwidefsky, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, linux-alpha, linux-kernel, linux-arm-kernel,
linux-ia64, linux-m68k, linux-mips, linux-parisc, linuxppc-dev,
linux-s390, linux-sh, sparclinux
On Mon, Mar 25, 2019 at 03:47:37PM +0100, Arnd Bergmann wrote:
> Add the io_uring and pidfd_send_signal system calls to all architectures.
>
> These system calls are designed to handle both native and compat tasks,
> so all entries are the same across architectures, only arm-compat and
> the generic tale still use an old format.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
> index 02579f95f391..3eb56e639b96 100644
> --- a/arch/s390/kernel/syscalls/syscall.tbl
> +++ b/arch/s390/kernel/syscalls/syscall.tbl
> @@ -426,3 +426,7 @@
> 421 32 rt_sigtimedwait_time64 - compat_sys_rt_sigtimedwait_time64
> 422 32 futex_time64 - sys_futex
> 423 32 sched_rr_get_interval_time64 - sys_sched_rr_get_interval
> +424 common pidfd_send_signal sys_pidfd_send_signal
> +425 common io_uring_setup sys_io_uring_setup
> +426 common io_uring_enter sys_io_uring_enter
> +427 common io_uring_register sys_io_uring_register
I was just about to write that io_uring_enter is missing compat
handling, but your first patch actually fixes that. Would have been
good to be cc'ed on both patches :)
For s390:
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-25 14:47 ` [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere Arnd Bergmann
2019-03-25 17:37 ` Paul Burton
2019-03-30 9:42 ` Heiko Carstens
@ 2019-03-31 9:47 ` Michael Ellerman
2019-03-31 16:28 ` Arnd Bergmann
2019-04-01 8:19 ` Geert Uytterhoeven
2019-04-03 2:47 ` Michael Ellerman
4 siblings, 1 reply; 16+ messages in thread
From: Michael Ellerman @ 2019-03-31 9:47 UTC (permalink / raw)
To: Arnd Bergmann, Andrew Morton
Cc: Richard Henderson, Ivan Kokshaysky, Matt Turner, Russell King,
Catalin Marinas, Will Deacon, Tony Luck, Fenghua Yu,
Geert Uytterhoeven, Michal Simek, Ralf Baechle, Paul Burton,
James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, linux-alpha, linux-kernel, linux-arm-kernel,
linux-ia64, linux-m68k, linux-mips, linux-parisc, linuxppc-dev,
linux-s390, linux-sh, sparclinux, Arnd Bergmann
Arnd Bergmann <arnd@arndb.de> writes:
> Add the io_uring and pidfd_send_signal system calls to all architectures.
>
> These system calls are designed to handle both native and compat tasks,
> so all entries are the same across architectures, only arm-compat and
> the generic tale still use an old format.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> arch/alpha/kernel/syscalls/syscall.tbl | 4 ++++
> arch/arm/tools/syscall.tbl | 4 ++++
> arch/arm64/include/asm/unistd.h | 2 +-
> arch/arm64/include/asm/unistd32.h | 8 ++++++++
> arch/ia64/kernel/syscalls/syscall.tbl | 4 ++++
> arch/m68k/kernel/syscalls/syscall.tbl | 4 ++++
> arch/microblaze/kernel/syscalls/syscall.tbl | 4 ++++
> arch/mips/kernel/syscalls/syscall_n32.tbl | 4 ++++
> arch/mips/kernel/syscalls/syscall_n64.tbl | 4 ++++
> arch/mips/kernel/syscalls/syscall_o32.tbl | 4 ++++
> arch/parisc/kernel/syscalls/syscall.tbl | 4 ++++
> arch/powerpc/kernel/syscalls/syscall.tbl | 4 ++++
Have you done any testing?
I'd rather not wire up syscalls that have never been tested at all on
powerpc.
cheers
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-31 9:47 ` Michael Ellerman
@ 2019-03-31 16:28 ` Arnd Bergmann
2019-04-03 1:19 ` Michael Ellerman
0 siblings, 1 reply; 16+ messages in thread
From: Arnd Bergmann @ 2019-03-31 16:28 UTC (permalink / raw)
To: Michael Ellerman
Cc: Andrew Morton, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Russell King, Catalin Marinas, Will Deacon, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
Paul Burton, James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, alpha, Linux Kernel Mailing List, Linux ARM,
linux-ia64, linux-m68k, linux-mips, Parisc List, linuxppc-dev,
linux-s390, Linux-sh list, sparclinux
On Sun, Mar 31, 2019 at 5:47 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> Arnd Bergmann <arnd@arndb.de> writes:
> > Add the io_uring and pidfd_send_signal system calls to all architectures.
> >
> > These system calls are designed to handle both native and compat tasks,
> > so all entries are the same across architectures, only arm-compat and
> > the generic tale still use an old format.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> > arch/alpha/kernel/syscalls/syscall.tbl | 4 ++++
> > arch/arm/tools/syscall.tbl | 4 ++++
> > arch/arm64/include/asm/unistd.h | 2 +-
> > arch/arm64/include/asm/unistd32.h | 8 ++++++++
> > arch/ia64/kernel/syscalls/syscall.tbl | 4 ++++
> > arch/m68k/kernel/syscalls/syscall.tbl | 4 ++++
> > arch/microblaze/kernel/syscalls/syscall.tbl | 4 ++++
> > arch/mips/kernel/syscalls/syscall_n32.tbl | 4 ++++
> > arch/mips/kernel/syscalls/syscall_n64.tbl | 4 ++++
> > arch/mips/kernel/syscalls/syscall_o32.tbl | 4 ++++
> > arch/parisc/kernel/syscalls/syscall.tbl | 4 ++++
> > arch/powerpc/kernel/syscalls/syscall.tbl | 4 ++++
>
> Have you done any testing?
>
> I'd rather not wire up syscalls that have never been tested at all on
> powerpc.
No, I have not. I did review the system calls carefully and added the first
patch to fix the bug on x86 compat mode before adding the same bug
on the other compat architectures though ;-)
Generally, my feeling is that adding system calls is not fundamentally
different from adding other ABIs, and we should really do it at
the same time across all architectures, rather than waiting for each
maintainer to get around to reviewing and testing the new calls
first. This is not a problem on powerpc, but a lot of other architectures
are less active, which is how we have always ended up with
different sets of system calls across architectures.
The problem here is that this makes it harder for the C library to
know when a system call is guaranteed to be available. glibc
still needs a feature test for newly added syscalls to see if they
are working (they might be backported to an older kernel, or
disabled), but whenever the minimum kernel version is increased,
it makes sense to drop those checks and assume non-optional
system calls will work if they were part of that minimum version.
In the future, I'd hope that any new system calls get added
right away on all architectures when they land (it was a bit
tricky this time, because I still did a bunch of reworks that
conflicted with the new calls). Bugs will happen of course, but
I think adding them sooner makes it more likely to catch those
bugs early on so we have a chance to fix them properly,
and need fewer arch specific workarounds (ideally none)
for system calls.
Arnd
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-31 16:28 ` Arnd Bergmann
@ 2019-04-03 1:19 ` Michael Ellerman
0 siblings, 0 replies; 16+ messages in thread
From: Michael Ellerman @ 2019-04-03 1:19 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Andrew Morton, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Russell King, Catalin Marinas, Will Deacon, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
Paul Burton, James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, alpha, Linux Kernel Mailing List, Linux ARM,
linux-ia64, linux-m68k, linux-mips, Parisc List, linuxppc-dev,
linux-s390, Linux-sh list, sparclinux
Arnd Bergmann <arnd@arndb.de> writes:
> On Sun, Mar 31, 2019 at 5:47 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>>
>> Arnd Bergmann <arnd@arndb.de> writes:
>> > Add the io_uring and pidfd_send_signal system calls to all architectures.
>> >
>> > These system calls are designed to handle both native and compat tasks,
>> > so all entries are the same across architectures, only arm-compat and
>> > the generic tale still use an old format.
>> >
>> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>> > ---
>> > arch/alpha/kernel/syscalls/syscall.tbl | 4 ++++
>> > arch/arm/tools/syscall.tbl | 4 ++++
>> > arch/arm64/include/asm/unistd.h | 2 +-
>> > arch/arm64/include/asm/unistd32.h | 8 ++++++++
>> > arch/ia64/kernel/syscalls/syscall.tbl | 4 ++++
>> > arch/m68k/kernel/syscalls/syscall.tbl | 4 ++++
>> > arch/microblaze/kernel/syscalls/syscall.tbl | 4 ++++
>> > arch/mips/kernel/syscalls/syscall_n32.tbl | 4 ++++
>> > arch/mips/kernel/syscalls/syscall_n64.tbl | 4 ++++
>> > arch/mips/kernel/syscalls/syscall_o32.tbl | 4 ++++
>> > arch/parisc/kernel/syscalls/syscall.tbl | 4 ++++
>> > arch/powerpc/kernel/syscalls/syscall.tbl | 4 ++++
>>
>> Have you done any testing?
>>
>> I'd rather not wire up syscalls that have never been tested at all on
>> powerpc.
>
> No, I have not. I did review the system calls carefully and added the first
> patch to fix the bug on x86 compat mode before adding the same bug
> on the other compat architectures though ;-)
>
> Generally, my feeling is that adding system calls is not fundamentally
> different from adding other ABIs, and we should really do it at
> the same time across all architectures, rather than waiting for each
> maintainer to get around to reviewing and testing the new calls
> first. This is not a problem on powerpc, but a lot of other architectures
> are less active, which is how we have always ended up with
> different sets of system calls across architectures.
Well it's still something of a problem on powerpc. No one has
volunteered to test io_uring on powerpc, so at this stage it will go in
completely untested.
If there was a selftest in the tree I'd be a bit happier, because at
least then our CI would start testing it as soon as the syscalls were
wired up in linux-next.
And yeah obviously I should test it, but I don't have infinite time
unfortunately.
> The problem here is that this makes it harder for the C library to
> know when a system call is guaranteed to be available. glibc
> still needs a feature test for newly added syscalls to see if they
> are working (they might be backported to an older kernel, or
> disabled), but whenever the minimum kernel version is increased,
> it makes sense to drop those checks and assume non-optional
> system calls will work if they were part of that minimum version.
But that's the thing, if we just wire them up untested they may not
actually work. And then you have the far worse situation where the
syscall exists in kernel version x but does not actually work properly.
See the mess we have with pkeys for example.
> In the future, I'd hope that any new system calls get added
> right away on all architectures when they land (it was a bit
> tricky this time, because I still did a bunch of reworks that
> conflicted with the new calls). Bugs will happen of course, but
> I think adding them sooner makes it more likely to catch those
> bugs early on so we have a chance to fix them properly,
> and need fewer arch specific workarounds (ideally none)
> for system calls.
For syscalls that have a selftest in the tree, and don't rely on
anything arch specific I agree.
I'm a bit more wary of things that are not easily tested and have the
potential to work differently across arches.
cheers
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-25 14:47 ` [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere Arnd Bergmann
` (2 preceding siblings ...)
2019-03-31 9:47 ` Michael Ellerman
@ 2019-04-01 8:19 ` Geert Uytterhoeven
2019-04-03 2:47 ` Michael Ellerman
4 siblings, 0 replies; 16+ messages in thread
From: Geert Uytterhoeven @ 2019-04-01 8:19 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Andrew Morton, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Russell King, Catalin Marinas, Will Deacon, Tony Luck,
Fenghua Yu, Michal Simek, Ralf Baechle, Paul Burton, James Hogan,
James E . J . Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, alpha, Linux Kernel Mailing List, Linux ARM,
linux-ia64, linux-m68k, linux-mips, Parisc List, linuxppc-dev,
linux-s390, Linux-sh list, sparclinux
On Mon, Mar 25, 2019 at 3:48 PM Arnd Bergmann <arnd@arndb.de> wrote:
> Add the io_uring and pidfd_send_signal system calls to all architectures.
>
> These system calls are designed to handle both native and compat tasks,
> so all entries are the same across architectures, only arm-compat and
> the generic tale still use an old format.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> arch/m68k/kernel/syscalls/syscall.tbl | 4 ++++
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-03-25 14:47 ` [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere Arnd Bergmann
` (3 preceding siblings ...)
2019-04-01 8:19 ` Geert Uytterhoeven
@ 2019-04-03 2:47 ` Michael Ellerman
2019-04-03 11:11 ` Will Deacon
4 siblings, 1 reply; 16+ messages in thread
From: Michael Ellerman @ 2019-04-03 2:47 UTC (permalink / raw)
To: Arnd Bergmann, Andrew Morton
Cc: Richard Henderson, Ivan Kokshaysky, Matt Turner, Russell King,
Catalin Marinas, Will Deacon, Tony Luck, Fenghua Yu,
Geert Uytterhoeven, Michal Simek, Ralf Baechle, Paul Burton,
James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, linux-alpha, linux-kernel, linux-arm-kernel,
linux-ia64, linux-m68k, linux-mips, linux-parisc, linuxppc-dev,
linux-s390, linux-sh, sparclinux, Arnd Bergmann, Jens Axboe
Arnd Bergmann <arnd@arndb.de> writes:
> diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
> index b18abb0c3dae..00f5a63c8d9a 100644
> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
> @@ -505,3 +505,7 @@
> 421 32 rt_sigtimedwait_time64 sys_rt_sigtimedwait compat_sys_rt_sigtimedwait_time64
> 422 32 futex_time64 sys_futex sys_futex
> 423 32 sched_rr_get_interval_time64 sys_sched_rr_get_interval sys_sched_rr_get_interval
> +424 common pidfd_send_signal sys_pidfd_send_signal
> +425 common io_uring_setup sys_io_uring_setup
> +426 common io_uring_enter sys_io_uring_enter
> +427 common io_uring_register sys_io_uring_register
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Lightly tested.
The pidfd_test selftest passes.
Ran the io_uring example from fio, which prints lots of:
IOPS=209952, IOS/call=32/32, inflight=117 (117), Cachehit=0.00%
IOPS=209952, IOS/call=32/32, inflight=116 (116), Cachehit=0.00%
IOPS=209920, IOS/call=32/32, inflight=115 (115), Cachehit=0.00%
IOPS=209952, IOS/call=32/32, inflight=115 (115), Cachehit=0.00%
IOPS=209920, IOS/call=32/32, inflight=115 (115), Cachehit=0.00%
IOPS=209952, IOS/call=32/32, inflight=115 (115), Cachehit=0.00%
IOPS=210016, IOS/call=32/32, inflight=114 (114), Cachehit=0.00%
IOPS=210016, IOS/call=32/32, inflight=113 (113), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=113 (113), Cachehit=0.00%
IOPS=210016, IOS/call=32/32, inflight=113 (113), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=112 (112), Cachehit=0.00%
IOPS=210016, IOS/call=32/32, inflight=110 (110), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=105 (105), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=104 (104), Cachehit=0.00%
IOPS=210080, IOS/call=32/32, inflight=102 (102), Cachehit=0.00%
IOPS=210112, IOS/call=32/32, inflight=100 (100), Cachehit=0.00%
IOPS=210080, IOS/call=32/32, inflight=97 (97), Cachehit=0.00%
IOPS=210112, IOS/call=32/32, inflight=97 (97), Cachehit=0.00%
IOPS=210112, IOS/call=32/31, inflight=126 (126), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=126 (126), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=125 (125), Cachehit=0.00%
IOPS=210016, IOS/call=32/32, inflight=119 (119), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=117 (117), Cachehit=0.00%
IOPS=210016, IOS/call=32/32, inflight=114 (114), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=111 (111), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=108 (108), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=107 (107), Cachehit=0.00%
IOPS=210048, IOS/call=32/32, inflight=105 (105), Cachehit=0.00%
Which is good I think?
cheers
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 2:47 ` Michael Ellerman
@ 2019-04-03 11:11 ` Will Deacon
2019-04-03 13:49 ` Jens Axboe
0 siblings, 1 reply; 16+ messages in thread
From: Will Deacon @ 2019-04-03 11:11 UTC (permalink / raw)
To: Michael Ellerman, axboe
Cc: Arnd Bergmann, Andrew Morton, Richard Henderson, Ivan Kokshaysky,
Matt Turner, Russell King, Catalin Marinas, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
Paul Burton, James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, linux-alpha, linux-kernel, linux-arm-kernel,
linux-ia64, linux-m68k, linux-mips, linux-parisc, linuxppc-dev,
linux-s390, linux-sh, sparclinux
Hi Michael,
On Wed, Apr 03, 2019 at 01:47:50PM +1100, Michael Ellerman wrote:
> Arnd Bergmann <arnd@arndb.de> writes:
> > diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
> > index b18abb0c3dae..00f5a63c8d9a 100644
> > --- a/arch/powerpc/kernel/syscalls/syscall.tbl
> > +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
> > @@ -505,3 +505,7 @@
> > 421 32 rt_sigtimedwait_time64 sys_rt_sigtimedwait compat_sys_rt_sigtimedwait_time64
> > 422 32 futex_time64 sys_futex sys_futex
> > 423 32 sched_rr_get_interval_time64 sys_sched_rr_get_interval sys_sched_rr_get_interval
> > +424 common pidfd_send_signal sys_pidfd_send_signal
> > +425 common io_uring_setup sys_io_uring_setup
> > +426 common io_uring_enter sys_io_uring_enter
> > +427 common io_uring_register sys_io_uring_register
>
> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
>
> Lightly tested.
>
> The pidfd_test selftest passes.
That reports pass for me too, although it fails to unshare the pid ns, which I
assume is benign.
> Ran the io_uring example from fio, which prints lots of:
How did you invoke that? I had a play with the tests in:
git://git.kernel.dk/liburing
but I quickly ran into the kernel oops below.
Will
--->8
will@autoplooker:~/liburing/test$ ./io_uring_register
RELIMIT_MEMLOCK: 67108864 (67108864)
[ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
[ 35.478969] Mem abort info:
[ 35.479296] ESR = 0x96000004
[ 35.479785] Exception class = DABT (current EL), IL = 32 bits
[ 35.480528] SET = 0, FnV = 0
[ 35.480980] EA = 0, S1PTW = 0
[ 35.481345] Data abort info:
[ 35.481680] ISV = 0, ISS = 0x00000004
[ 35.482267] CM = 0, WnR = 0
[ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
[ 35.483486] [0000000000000070] pgd=0000000000000000
[ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 35.484788] Modules linked in:
[ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
[ 35.486712] Hardware name: linux,dummy-virt (DT)
[ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
[ 35.488228] pc : link_pwq+0x10/0x60
[ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
[ 35.489550] sp : ffff000017e2bbc0
[ 35.490088] x29: ffff000017e2bbc0 x28: ffff8004b9118000
[ 35.490939] x27: 0000000000000000 x26: ffff8004c21c4200
[ 35.491786] x25: 0000000000000004 x24: ffff00001123e1b0
[ 35.492640] x23: ffff8004c5390000 x22: ffff8004bb440500
[ 35.493502] x21: ffff8004bb440500 x20: 0000000000000070
[ 35.494355] x19: 0000000000000022 x18: 0000000000000000
[ 35.495202] x17: 0000000000000000 x16: 0000000000000000
[ 35.496054] x15: 0000000000000000 x14: ffff7e0012e8a240
[ 35.496910] x13: 00004a73a5e663e2 x12: 0000000000000000
[ 35.497764] x11: 0000000000000001 x10: 0000000000000070
[ 35.498611] x9 : ffff8004cb49d610 x8 : 00000000ffffffff
[ 35.499462] x7 : ffff8004c4ff9c70 x6 : ffff8004cb49ccb0
[ 35.500308] x5 : ffff8004c66cc4c0 x4 : 0000000000000001
[ 35.501173] x3 : 0000000000000000 x2 : 0000000000000040
[ 35.502019] x1 : 0000000000000004 x0 : 0000000000000000
[ 35.502872] Process io_uring_regist (pid: 3973, stack limit = 0x(____ptrval____))
[ 35.504052] Call trace:
[ 35.504463] link_pwq+0x10/0x60
[ 35.504987] apply_wqattrs_commit+0xe0/0x118
[ 35.505681] apply_workqueue_attrs_locked+0x3c/0x80
[ 35.506460] apply_workqueue_attrs+0x3c/0x60
[ 35.507152] alloc_workqueue+0x264/0x430
[ 35.507786] io_uring_setup+0x478/0x6a8
[ 35.508414] __arm64_sys_io_uring_setup+0x18/0x20
[ 35.509183] el0_svc_common+0x80/0xf0
[ 35.509786] el0_svc_handler+0x2c/0x80
[ 35.510393] el0_svc+0x8/0xc
[ 35.510873] Code: a9bd7bfd 910003fd a90153f3 9101c014 (f9403802)
[ 35.511843] ---[ end trace 0a53e45ee26def4c ]---
Segmentation fault
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 11:11 ` Will Deacon
@ 2019-04-03 13:49 ` Jens Axboe
2019-04-03 15:19 ` Will Deacon
2019-04-04 6:08 ` Michael Ellerman
0 siblings, 2 replies; 16+ messages in thread
From: Jens Axboe @ 2019-04-03 13:49 UTC (permalink / raw)
To: Will Deacon, Michael Ellerman
Cc: Arnd Bergmann, Andrew Morton, Richard Henderson, Ivan Kokshaysky,
Matt Turner, Russell King, Catalin Marinas, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
Paul Burton, James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, linux-alpha, linux-kernel, linux-arm-kernel,
linux-ia64, linux-m68k, linux-mips, linux-parisc, linuxppc-dev,
linux-s390, linux-sh, sparclinux
On 4/3/19 5:11 AM, Will Deacon wrote:
> Hi Michael,
>
> On Wed, Apr 03, 2019 at 01:47:50PM +1100, Michael Ellerman wrote:
>> Arnd Bergmann <arnd@arndb.de> writes:
>>> diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
>>> index b18abb0c3dae..00f5a63c8d9a 100644
>>> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
>>> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
>>> @@ -505,3 +505,7 @@
>>> 421 32 rt_sigtimedwait_time64 sys_rt_sigtimedwait compat_sys_rt_sigtimedwait_time64
>>> 422 32 futex_time64 sys_futex sys_futex
>>> 423 32 sched_rr_get_interval_time64 sys_sched_rr_get_interval sys_sched_rr_get_interval
>>> +424 common pidfd_send_signal sys_pidfd_send_signal
>>> +425 common io_uring_setup sys_io_uring_setup
>>> +426 common io_uring_enter sys_io_uring_enter
>>> +427 common io_uring_register sys_io_uring_register
>>
>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
>>
>> Lightly tested.
>>
>> The pidfd_test selftest passes.
>
> That reports pass for me too, although it fails to unshare the pid ns, which I
> assume is benign.
>
>> Ran the io_uring example from fio, which prints lots of:
>
> How did you invoke that? I had a play with the tests in:
It's t/io_uring from the fio repo:
git://git.kernel.dk/fio
and you just run it ala:
# make t/io_uring
# t/io_uring /dev/some_device
> git://git.kernel.dk/liburing
>
> but I quickly ran into the kernel oops below.
>
> Will
>
> --->8
>
> will@autoplooker:~/liburing/test$ ./io_uring_register
> RELIMIT_MEMLOCK: 67108864 (67108864)
> [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
> [ 35.478969] Mem abort info:
> [ 35.479296] ESR = 0x96000004
> [ 35.479785] Exception class = DABT (current EL), IL = 32 bits
> [ 35.480528] SET = 0, FnV = 0
> [ 35.480980] EA = 0, S1PTW = 0
> [ 35.481345] Data abort info:
> [ 35.481680] ISV = 0, ISS = 0x00000004
> [ 35.482267] CM = 0, WnR = 0
> [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
> [ 35.483486] [0000000000000070] pgd=0000000000000000
> [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> [ 35.484788] Modules linked in:
> [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
> [ 35.486712] Hardware name: linux,dummy-virt (DT)
> [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
> [ 35.488228] pc : link_pwq+0x10/0x60
> [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
> [ 35.489550] sp : ffff000017e2bbc0
Huh, this looks odd, it's crashing inside the wq setup.
--
Jens Axboe
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 13:49 ` Jens Axboe
@ 2019-04-03 15:19 ` Will Deacon
2019-04-03 15:39 ` Jens Axboe
2019-04-04 6:08 ` Michael Ellerman
1 sibling, 1 reply; 16+ messages in thread
From: Will Deacon @ 2019-04-03 15:19 UTC (permalink / raw)
To: Jens Axboe
Cc: Michael Ellerman, Arnd Bergmann, Andrew Morton,
Richard Henderson, Ivan Kokshaysky, Matt Turner, Russell King,
Catalin Marinas, Tony Luck, Fenghua Yu, Geert Uytterhoeven,
Michal Simek, Ralf Baechle, Paul Burton, James Hogan,
James E . J . Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Martin Schwidefsky, Heiko Carstens, Rich Felker,
David S . Miller, Max Filippov, Firoz Khan, linux-alpha,
linux-kernel, linux-arm-kernel, linux-ia64, linux-m68k,
linux-mips, linux-parisc, linuxppc-dev, linux-s390, linux-sh,
sparclinux
Hi Jens,
On Wed, Apr 03, 2019 at 07:49:26AM -0600, Jens Axboe wrote:
> On 4/3/19 5:11 AM, Will Deacon wrote:
> > will@autoplooker:~/liburing/test$ ./io_uring_register
> > RELIMIT_MEMLOCK: 67108864 (67108864)
> > [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
> > [ 35.478969] Mem abort info:
> > [ 35.479296] ESR = 0x96000004
> > [ 35.479785] Exception class = DABT (current EL), IL = 32 bits
> > [ 35.480528] SET = 0, FnV = 0
> > [ 35.480980] EA = 0, S1PTW = 0
> > [ 35.481345] Data abort info:
> > [ 35.481680] ISV = 0, ISS = 0x00000004
> > [ 35.482267] CM = 0, WnR = 0
> > [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
> > [ 35.483486] [0000000000000070] pgd=0000000000000000
> > [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> > [ 35.484788] Modules linked in:
> > [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
> > [ 35.486712] Hardware name: linux,dummy-virt (DT)
> > [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
> > [ 35.488228] pc : link_pwq+0x10/0x60
> > [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
> > [ 35.489550] sp : ffff000017e2bbc0
>
> Huh, this looks odd, it's crashing inside the wq setup.
Enabling KASAN seems to indicate a double-free, which may well be related.
Will
[ 149.890370] ==================================================================
[ 149.891266] BUG: KASAN: double-free or invalid-free in io_sqe_files_unregister+0xa8/0x140
[ 149.892218]
[ 149.892411] CPU: 113 PID: 3974 Comm: io_uring_regist Tainted: G B 5.1.0-rc3-00012-g40b114779944 #3
[ 149.893623] Hardware name: linux,dummy-virt (DT)
[ 149.894169] Call trace:
[ 149.894539] dump_backtrace+0x0/0x228
[ 149.895172] show_stack+0x14/0x20
[ 149.895747] dump_stack+0xe8/0x124
[ 149.896335] print_address_description+0x60/0x258
[ 149.897148] kasan_report_invalid_free+0x78/0xb8
[ 149.897936] __kasan_slab_free+0x1fc/0x228
[ 149.898641] kasan_slab_free+0x10/0x18
[ 149.899283] kfree+0x70/0x1f8
[ 149.899798] io_sqe_files_unregister+0xa8/0x140
[ 149.900574] io_ring_ctx_wait_and_kill+0x190/0x3c0
[ 149.901402] io_uring_release+0x2c/0x48
[ 149.902068] __fput+0x18c/0x510
[ 149.902612] ____fput+0xc/0x18
[ 149.903146] task_work_run+0xf0/0x148
[ 149.903778] do_notify_resume+0x554/0x748
[ 149.904467] work_pending+0x8/0x10
[ 149.905060]
[ 149.905331] Allocated by task 3974:
[ 149.905934] __kasan_kmalloc.isra.0.part.1+0x48/0xf8
[ 149.906786] __kasan_kmalloc.isra.0+0xb8/0xd8
[ 149.907531] kasan_kmalloc+0xc/0x18
[ 149.908134] __kmalloc+0x168/0x248
[ 149.908724] __arm64_sys_io_uring_register+0x2b8/0x15a8
[ 149.909622] el0_svc_common+0x100/0x258
[ 149.910281] el0_svc_handler+0x48/0xc0
[ 149.910928] el0_svc+0x8/0xc
[ 149.911425]
[ 149.911696] Freed by task 3974:
[ 149.912242] __kasan_slab_free+0x114/0x228
[ 149.912955] kasan_slab_free+0x10/0x18
[ 149.913602] kfree+0x70/0x1f8
[ 149.914118] __arm64_sys_io_uring_register+0xc2c/0x15a8
[ 149.915009] el0_svc_common+0x100/0x258
[ 149.915670] el0_svc_handler+0x48/0xc0
[ 149.916317] el0_svc+0x8/0xc
[ 149.916817]
[ 149.917101] The buggy address belongs to the object at ffff8004ce07ed00
[ 149.917101] which belongs to the cache kmalloc-128 of size 128
[ 149.919197] The buggy address is located 0 bytes inside of
[ 149.919197] 128-byte region [ffff8004ce07ed00, ffff8004ce07ed80)
[ 149.921142] The buggy address belongs to the page:
[ 149.921953] page:ffff7e0013381f00 count:1 mapcount:0 mapping:ffff800503417c00 index:0x0 compound_mapcount: 0
[ 149.923595] flags: 0x1ffff00000010200(slab|head)
[ 149.924388] raw: 1ffff00000010200 dead000000000100 dead000000000200 ffff800503417c00
[ 149.925706] raw: 0000000000000000 0000000080400040 00000001ffffffff 0000000000000000
[ 149.927011] page dumped because: kasan: bad access detected
[ 149.927956]
[ 149.928224] Memory state around the buggy address:
[ 149.929054] ffff8004ce07ec00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[ 149.930274] ffff8004ce07ec80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 149.931494] >ffff8004ce07ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 149.932712] ^
[ 149.933281] ffff8004ce07ed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 149.934508] ffff8004ce07ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 149.935725] ==================================================================
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 15:19 ` Will Deacon
@ 2019-04-03 15:39 ` Jens Axboe
2019-04-03 15:49 ` Will Deacon
0 siblings, 1 reply; 16+ messages in thread
From: Jens Axboe @ 2019-04-03 15:39 UTC (permalink / raw)
To: Will Deacon
Cc: Michael Ellerman, Arnd Bergmann, Andrew Morton,
Richard Henderson, Ivan Kokshaysky, Matt Turner, Russell King,
Catalin Marinas, Tony Luck, Fenghua Yu, Geert Uytterhoeven,
Michal Simek, Ralf Baechle, Paul Burton, James Hogan,
James E . J . Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Martin Schwidefsky, Heiko Carstens, Rich Felker,
David S . Miller, Max Filippov, Firoz Khan, linux-alpha,
linux-kernel, linux-arm-kernel, linux-ia64, linux-m68k,
linux-mips, linux-parisc, linuxppc-dev, linux-s390, linux-sh,
sparclinux
On 4/3/19 9:19 AM, Will Deacon wrote:
> Hi Jens,
>
> On Wed, Apr 03, 2019 at 07:49:26AM -0600, Jens Axboe wrote:
>> On 4/3/19 5:11 AM, Will Deacon wrote:
>>> will@autoplooker:~/liburing/test$ ./io_uring_register
>>> RELIMIT_MEMLOCK: 67108864 (67108864)
>>> [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
>>> [ 35.478969] Mem abort info:
>>> [ 35.479296] ESR = 0x96000004
>>> [ 35.479785] Exception class = DABT (current EL), IL = 32 bits
>>> [ 35.480528] SET = 0, FnV = 0
>>> [ 35.480980] EA = 0, S1PTW = 0
>>> [ 35.481345] Data abort info:
>>> [ 35.481680] ISV = 0, ISS = 0x00000004
>>> [ 35.482267] CM = 0, WnR = 0
>>> [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
>>> [ 35.483486] [0000000000000070] pgd=0000000000000000
>>> [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
>>> [ 35.484788] Modules linked in:
>>> [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
>>> [ 35.486712] Hardware name: linux,dummy-virt (DT)
>>> [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
>>> [ 35.488228] pc : link_pwq+0x10/0x60
>>> [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
>>> [ 35.489550] sp : ffff000017e2bbc0
>>
>> Huh, this looks odd, it's crashing inside the wq setup.
>
> Enabling KASAN seems to indicate a double-free, which may well be related.
Does this help?
diff --git a/fs/io_uring.c b/fs/io_uring.c
index bbdbd56cf2ac..07d6ef195d05 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2215,6 +2215,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
fput(ctx->user_files[i]);
kfree(ctx->user_files);
+ ctx->user_files = NULL;
ctx->nr_user_files = 0;
return ret;
}
--
Jens Axboe
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 15:39 ` Jens Axboe
@ 2019-04-03 15:49 ` Will Deacon
2019-04-03 15:51 ` Jens Axboe
0 siblings, 1 reply; 16+ messages in thread
From: Will Deacon @ 2019-04-03 15:49 UTC (permalink / raw)
To: Jens Axboe
Cc: Michael Ellerman, Arnd Bergmann, Andrew Morton,
Richard Henderson, Ivan Kokshaysky, Matt Turner, Russell King,
Catalin Marinas, Tony Luck, Fenghua Yu, Geert Uytterhoeven,
Michal Simek, Ralf Baechle, Paul Burton, James Hogan,
James E . J . Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Martin Schwidefsky, Heiko Carstens, Rich Felker,
David S . Miller, Max Filippov, Firoz Khan, linux-alpha,
linux-kernel, linux-arm-kernel, linux-ia64, linux-m68k,
linux-mips, linux-parisc, linuxppc-dev, linux-s390, linux-sh,
sparclinux
On Wed, Apr 03, 2019 at 09:39:52AM -0600, Jens Axboe wrote:
> On 4/3/19 9:19 AM, Will Deacon wrote:
> > On Wed, Apr 03, 2019 at 07:49:26AM -0600, Jens Axboe wrote:
> >> On 4/3/19 5:11 AM, Will Deacon wrote:
> >>> will@autoplooker:~/liburing/test$ ./io_uring_register
> >>> RELIMIT_MEMLOCK: 67108864 (67108864)
> >>> [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
> >>> [ 35.478969] Mem abort info:
> >>> [ 35.479296] ESR = 0x96000004
> >>> [ 35.479785] Exception class = DABT (current EL), IL = 32 bits
> >>> [ 35.480528] SET = 0, FnV = 0
> >>> [ 35.480980] EA = 0, S1PTW = 0
> >>> [ 35.481345] Data abort info:
> >>> [ 35.481680] ISV = 0, ISS = 0x00000004
> >>> [ 35.482267] CM = 0, WnR = 0
> >>> [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
> >>> [ 35.483486] [0000000000000070] pgd=0000000000000000
> >>> [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> >>> [ 35.484788] Modules linked in:
> >>> [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
> >>> [ 35.486712] Hardware name: linux,dummy-virt (DT)
> >>> [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
> >>> [ 35.488228] pc : link_pwq+0x10/0x60
> >>> [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
> >>> [ 35.489550] sp : ffff000017e2bbc0
> >>
> >> Huh, this looks odd, it's crashing inside the wq setup.
> >
> > Enabling KASAN seems to indicate a double-free, which may well be related.
>
> Does this help?
Yes, thanks for the quick patch. Feel free to add:
Reported-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
if you spin a proper patch.
Will
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index bbdbd56cf2ac..07d6ef195d05 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2215,6 +2215,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
> fput(ctx->user_files[i]);
>
> kfree(ctx->user_files);
> + ctx->user_files = NULL;
> ctx->nr_user_files = 0;
> return ret;
> }
>
> --
> Jens Axboe
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 15:49 ` Will Deacon
@ 2019-04-03 15:51 ` Jens Axboe
0 siblings, 0 replies; 16+ messages in thread
From: Jens Axboe @ 2019-04-03 15:51 UTC (permalink / raw)
To: Will Deacon
Cc: Michael Ellerman, Arnd Bergmann, Andrew Morton,
Richard Henderson, Ivan Kokshaysky, Matt Turner, Russell King,
Catalin Marinas, Tony Luck, Fenghua Yu, Geert Uytterhoeven,
Michal Simek, Ralf Baechle, Paul Burton, James Hogan,
James E . J . Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Martin Schwidefsky, Heiko Carstens, Rich Felker,
David S . Miller, Max Filippov, Firoz Khan, linux-alpha,
linux-kernel, linux-arm-kernel, linux-ia64, linux-m68k,
linux-mips, linux-parisc, linuxppc-dev, linux-s390, linux-sh,
sparclinux
On 4/3/19 9:49 AM, Will Deacon wrote:
> On Wed, Apr 03, 2019 at 09:39:52AM -0600, Jens Axboe wrote:
>> On 4/3/19 9:19 AM, Will Deacon wrote:
>>> On Wed, Apr 03, 2019 at 07:49:26AM -0600, Jens Axboe wrote:
>>>> On 4/3/19 5:11 AM, Will Deacon wrote:
>>>>> will@autoplooker:~/liburing/test$ ./io_uring_register
>>>>> RELIMIT_MEMLOCK: 67108864 (67108864)
>>>>> [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
>>>>> [ 35.478969] Mem abort info:
>>>>> [ 35.479296] ESR = 0x96000004
>>>>> [ 35.479785] Exception class = DABT (current EL), IL = 32 bits
>>>>> [ 35.480528] SET = 0, FnV = 0
>>>>> [ 35.480980] EA = 0, S1PTW = 0
>>>>> [ 35.481345] Data abort info:
>>>>> [ 35.481680] ISV = 0, ISS = 0x00000004
>>>>> [ 35.482267] CM = 0, WnR = 0
>>>>> [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
>>>>> [ 35.483486] [0000000000000070] pgd=0000000000000000
>>>>> [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
>>>>> [ 35.484788] Modules linked in:
>>>>> [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
>>>>> [ 35.486712] Hardware name: linux,dummy-virt (DT)
>>>>> [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
>>>>> [ 35.488228] pc : link_pwq+0x10/0x60
>>>>> [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
>>>>> [ 35.489550] sp : ffff000017e2bbc0
>>>>
>>>> Huh, this looks odd, it's crashing inside the wq setup.
>>>
>>> Enabling KASAN seems to indicate a double-free, which may well be related.
>>
>> Does this help?
>
> Yes, thanks for the quick patch. Feel free to add:
>
> Reported-by: Will Deacon <will.deacon@arm.com>
> Tested-by: Will Deacon <will.deacon@arm.com>
>
> if you spin a proper patch.
Great, thanks for reporting/testing.
--
Jens Axboe
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] arch: add pidfd and io_uring syscalls everywhere
2019-04-03 13:49 ` Jens Axboe
2019-04-03 15:19 ` Will Deacon
@ 2019-04-04 6:08 ` Michael Ellerman
1 sibling, 0 replies; 16+ messages in thread
From: Michael Ellerman @ 2019-04-04 6:08 UTC (permalink / raw)
To: Jens Axboe, Will Deacon
Cc: Arnd Bergmann, Andrew Morton, Richard Henderson, Ivan Kokshaysky,
Matt Turner, Russell King, Catalin Marinas, Tony Luck,
Fenghua Yu, Geert Uytterhoeven, Michal Simek, Ralf Baechle,
Paul Burton, James Hogan, James E . J . Bottomley, Helge Deller,
Benjamin Herrenschmidt, Paul Mackerras, Martin Schwidefsky,
Heiko Carstens, Rich Felker, David S . Miller, Max Filippov,
Firoz Khan, linux-alpha, linux-kernel, linux-arm-kernel,
linux-ia64, linux-m68k, linux-mips, linux-parisc, linuxppc-dev,
linux-s390, linux-sh, sparclinux
Jens Axboe <axboe@kernel.dk> writes:
> On 4/3/19 5:11 AM, Will Deacon wrote:
>> On Wed, Apr 03, 2019 at 01:47:50PM +1100, Michael Ellerman wrote:
>>> Arnd Bergmann <arnd@arndb.de> writes:
>>>> diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
>>>> index b18abb0c3dae..00f5a63c8d9a 100644
>>>> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
>>>> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
>>>> @@ -505,3 +505,7 @@
>>>> 421 32 rt_sigtimedwait_time64 sys_rt_sigtimedwait compat_sys_rt_sigtimedwait_time64
>>>> 422 32 futex_time64 sys_futex sys_futex
>>>> 423 32 sched_rr_get_interval_time64 sys_sched_rr_get_interval sys_sched_rr_get_interval
>>>> +424 common pidfd_send_signal sys_pidfd_send_signal
>>>> +425 common io_uring_setup sys_io_uring_setup
>>>> +426 common io_uring_enter sys_io_uring_enter
>>>> +427 common io_uring_register sys_io_uring_register
>>>
>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
>>>
>>> Lightly tested.
>>>
>>> The pidfd_test selftest passes.
>>
>> That reports pass for me too, although it fails to unshare the pid ns, which I
>> assume is benign.
If you run it as root it should work?
>>> Ran the io_uring example from fio, which prints lots of:
>>
>> How did you invoke that? I had a play with the tests in:
>
> It's t/io_uring from the fio repo:
>
> git://git.kernel.dk/fio
>
> and you just run it ala:
>
> # make t/io_uring
> # t/io_uring /dev/some_device
Yeah that's all I did.
>> will@autoplooker:~/liburing/test$ ./io_uring_register
>> RELIMIT_MEMLOCK: 67108864 (67108864)
>> [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
>> [ 35.478969] Mem abort info:
>> [ 35.479296] ESR = 0x96000004
>> [ 35.479785] Exception class = DABT (current EL), IL = 32 bits
>> [ 35.480528] SET = 0, FnV = 0
>> [ 35.480980] EA = 0, S1PTW = 0
>> [ 35.481345] Data abort info:
>> [ 35.481680] ISV = 0, ISS = 0x00000004
>> [ 35.482267] CM = 0, WnR = 0
>> [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
>> [ 35.483486] [0000000000000070] pgd=0000000000000000
>> [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP
>> [ 35.484788] Modules linked in:
>> [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1
>> [ 35.486712] Hardware name: linux,dummy-virt (DT)
>> [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO)
>> [ 35.488228] pc : link_pwq+0x10/0x60
>> [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118
>> [ 35.489550] sp : ffff000017e2bbc0
>
> Huh, this looks odd, it's crashing inside the wq setup.
Looks like you found a bug :)
cheers
^ permalink raw reply [flat|nested] 16+ messages in thread