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2770ef7c8a
1908 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Masahiro Yamada
|
2770ef7c8a |
ia64: do not typedef struct pal_min_state_area_s
Documentation/process/coding-style.rst says:
Please don't use things like ``vps_t``.
It's a **mistake** to use typedef for structures and pointers.
This commit converts as follows:
struct pal_min_state_area_s -> struct pal_min_state_area
pal_min_state_area_t -> struct pal_min_state_area
My main motivation for this is to slim down the include directives
of <asm/mca.h> in the next commit.
Currently, <asm/mca.h> is required to include <asm/pal.h> directly
or indirectly due to (pal_min_state_area_t *). Otherwise, it would
have no idea what pal_min_state_area_t is.
Replacing it with (struct pal_min_state_area *) will relax the header
dependency since it is enough to tell it is a pointer to a structure,
and to resolve the size of struct pal_min_state_area. It will make
<asm/mca.h> independent of <asm/pal.h>.
<asm/pal.h> typedef's a lot of structures, but it is trivial to
convert the others in the same way.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
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||
Arnd Bergmann
|
796130b1de |
ia64: fix timer cleanup regression
A cleanup patch from my legacy timer series broke ia64 and led
to RCU stall errors and a fast system clock:
[ 909.360108] INFO: task systemd-sysv-ge:200 blocked for more than 127 seconds.
[ 909.360108] Not tainted 5.10.0+ #130
[ 909.360108] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 909.360108] task:systemd-sysv-ge state:D stack: 0 pid: 200 ppid: 189 flags:0x00000000
[ 909.364108]
[ 909.364108] Call Trace:
[ 909.364423] [<a00000010109b210>] __schedule+0x890/0x21e0
[ 909.364423] sp=e0000100487d7b70 bsp=e0000100487d1748
[ 909.368423] [<a00000010109cc00>] schedule+0xa0/0x240
[ 909.368423] sp=e0000100487d7b90 bsp=e0000100487d16e0
[ 909.368558] [<a00000010109ce70>] io_schedule+0x70/0xa0
[ 909.368558] sp=e0000100487d7b90 bsp=e0000100487d16c0
[ 909.372290] [<a00000010109e1c0>] bit_wait_io+0x20/0xe0
[ 909.372290] sp=e0000100487d7b90 bsp=e0000100487d1698
[ 909.374168] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 909.376290] [<a00000010109d860>] __wait_on_bit+0xc0/0x1c0
[ 909.376290] sp=e0000100487d7b90 bsp=e0000100487d1648
[ 909.374168] rcu: 3-....: (2 ticks this GP) idle=19e/1/0x4000000000000002 softirq=1581/1581 fqs=2
[ 909.374168] (detected by 0, t=5661 jiffies, g=1089, q=3)
[ 909.376290] [<a00000010109da80>] out_of_line_wait_on_bit+0x120/0x140
[ 909.376290] sp=e0000100487d7b90 bsp=e0000100487d1610
[ 909.374168] Task dump for CPU 3:
[ 909.374168] task:khungtaskd state:R running task
Revert most of my patch to make this work again, including the extra
update_process_times()/profile_tick() and the local_irq_enable() in the
loop that I expected not to be needed here.
I have not found out exactly what goes wrong, and would suggest that
someone with hardware access tries to convert this code into a singleshot
clockevent driver, which should give better behavior in all cases.
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Fixes:
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Willem de Bruijn
|
b0a0c2615f |
epoll: wire up syscall epoll_pwait2
Split off from prev patch in the series that implements the syscall. Link: https://lkml.kernel.org/r/20201121144401.3727659-4-willemdebruijn.kernel@gmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds
|
005b2a9dc8 |
tif-task_work.arch-2020-12-14
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Linus Torvalds
|
7a932e5702 |
asm-generic: cross-architecture timer cleanup
This cleans up two ancient timer features that were never completed in the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET. There was only one user left for the ARCH_USES_GETTIMEOFFSET variant of clocksource implementations, the ARM EBSA110 platform. Rather than changing to use modern timekeeping, we remove the platform entirely as Russell no longer uses his machine and nobody else seems to have one any more. The conditional code for using arch_gettimeoffset() is removed as a result. For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms not using clockevent drivers: parisc, ia64, most of m68k, and one Arm platform. These all do timer ticks slighly differently, and this gets cleaned up to the point they at least all call the same helper function. Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in Kconfig, the polarity is now reversed, with the few remaining ones selecting LEGACY_TIMER_TICK instead. Signed-off-by: Arnd Bergmann <arnd@arndb.de> -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEo6/YBQwIrVS28WGKmmx57+YAGNkFAl/Y1v8ACgkQmmx57+YA GNmCvQ/9EDlgCt92r8SB+LGafDtgB8TUQZeIrs9S2mByzdxwnw0lxObIXFCnhQgh RpG3dR+ONRDnC5eI149B377JOEFMZWe2+BtYHUHkFARtUEWatslQcz7yAGvVRK/l TS/qReb6piKltlzuanF1bMZbjy2OhlaDRcm+OlC3y5mALR33M4emb+rJ6cSdfk3K v1iZhrxtfQT77ztesh/oPkPiyQ6kNcz7SfpyYOb6f5VLlml2BZ7YwBSVyGY7urHk RL3XqOUP4KKlMEAI8w0E2nvft6Fk+luziBhrMYWK0GvbmI1OESENuX/c6tgT2OQ1 DRaVHvcPG/EAY8adOKxxVyHhEJDSoz5GJV/EtjlOegsJk6RomczR1uuiT3Kvm7Ah PktMKv4xQht1E15KPSKbOvNIEP18w2s5z6gw+jVDv8pw42pVEQManm1D+BICqrhl fcpw6T1drf9UxAjwX4+zXtmNs+a+mqiFG8puU4VVgT4GpQ8umHvunXz2WUjZO0jc 3m8ErJHBvtJwW5TOHGyXnjl9SkwPzHOfF6IcXTYWEDU4/gQIK9TwUvCjLc0lE27t FMCV2ds7/K1CXwRgpa5IrefSkb8yOXSbRZ56NqqF7Ekxw4J5bYRSaY7jb+qD/e+3 5O1y+iPxFrpH+16hSahvzrtcdFNbLQvBBuRtEQOYuHLt2UJrNoU= =QpNs -----END PGP SIGNATURE----- Merge tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann: "This cleans up two ancient timer features that were never completed in the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET. There was only one user left for the ARCH_USES_GETTIMEOFFSET variant of clocksource implementations, the ARM EBSA110 platform. Rather than changing to use modern timekeeping, we remove the platform entirely as Russell no longer uses his machine and nobody else seems to have one any more. The conditional code for using arch_gettimeoffset() is removed as a result. For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms not using clockevent drivers: parisc, ia64, most of m68k, and one Arm platform. These all do timer ticks slighly differently, and this gets cleaned up to the point they at least all call the same helper function. Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in Kconfig, the polarity is now reversed, with the few remaining ones selecting LEGACY_TIMER_TICK instead" * tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: timekeeping: default GENERIC_CLOCKEVENTS to enabled timekeeping: remove xtime_update m68k: remove timer_interrupt() function m68k: change remaining timers to legacy_timer_tick m68k: m68328: use legacy_timer_tick() m68k: sun3/sun3c: use legacy_timer_tick m68k: split heartbeat out of timer function m68k: coldfire: use legacy_timer_tick() parisc: use legacy_timer_tick ARM: rpc: use legacy_timer_tick ia64: convert to legacy_timer_tick timekeeping: add CONFIG_LEGACY_TIMER_TICK timekeeping: remove arch_gettimeoffset net: remove am79c961a driver ARM: remove ebsa110 platform |
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Linus Torvalds
|
37373d9c37 |
Merge branch 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull regset updates from Al Viro: "Dead code removal, mostly. The only exception is a bit of cleanups on itanic (getting rid of redundant stack unwinds - each access_uarea() call does it and we call that 7 times in a row in ptrace_[sg]etregs(), *after* having done it ourselves in the caller; location where the user registers have been spilled won't change under us, and we can bloody well just call access_elf_reg() directly, giving it the unw_frame_info we'd calculated for our own purposes)" * 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: c6x: kill ELF_CORE_COPY_FPREGS whack-a-mole: USE_ELF_CORE_DUMP [ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea() [ia64] missed cleanups from switch to regset coredumps arm: kill dump_task_regs() |
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Thomas Gleixner
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3c41e57a1e |
irqchip updates for Linux 5.11
- Preliminary support for managed interrupts on platform devices - Correctly identify allocation of MSIs proxyied by another device - Remove the fasteoi IPI flow which has been proved useless - Generalise the Ocelot support to new SoCs - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation - Work around spurious interrupts on Qualcomm PDC - Random fixes and cleanups -----BEGIN PGP SIGNATURE----- iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl/Uxq8PHG1hekBrZXJu ZWwub3JnAAoJECPQ0LrRPXpDoW0P/0ZMDvFPxrfnJD46exUgUOPuuFF8jZxAlxD8 7UExqar7u6yX7bbq394jPgtOOxldDagfCx/jCXgb9ja7DK5EHKRcrfjaDT8knHi2 Keg5RaRMRi9TVltvWQTxAkXwSv0Atl881qqsndPeZCez0GNZp+HB34s+rNkZwBOu MBrWihMQOSv5QE6milsNc7HXLSHM1eLZ7Y2XgumNtKrIGEX9yZI7qwdMofwP8Za3 ayMOvc1WAWaTJI7Mg5ac1yTCVbqLmRHhCtws6c6DMgaRu6SI0itmbpQzkDuJJIe3 k9h4KQPaKAFcQsoo3GV0MKTMm63eq82XT3CAdv+htYRY1z95D2+nzNK+mJtsGptX gJ2zeJkUb4u+yVtNguL9qjo5ssCXV/6IybJxv6baaEFnSwQMUwqa066NdxmtqfIe 1BOWnc153a7SRbQ34M9/llje+v8YJbueGMS2RFR2LQ6IjjpaHsXh+YCZokfA/kdk zGbOUD5WWFtFD1T3UoaJ4gFt+pzHjNqym4CcEj4S1Vf5y+POUkNmC+GYK+xfm2Fp WJMbdIUxJhHFRD9L1ShtfAVUSbp712VOOdILp9rYAkOdqfb51BVUiMUP++s2dGp1 ZIT78qt7kTKT1CxbDdFAjzsi7RoMqdSGYgKmG4sVprELeZnFwq47nBkBr8XEQ1TT 0ccEUOY8 =7Z24 -----END PGP SIGNATURE----- Merge tag 'irqchip-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core Pull irqchip updates for 5.11 from Marc Zyngier: - Preliminary support for managed interrupts on platform devices - Correctly identify allocation of MSIs proxyied by another device - Remove the fasteoi IPI flow which has been proved useless - Generalise the Ocelot support to new SoCs - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation - Work around spurious interrupts on Qualcomm PDC - Random fixes and cleanups Link: https://lore.kernel.org/r/20201212135626.1479884-1-maz@kernel.org |
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Jens Axboe
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b269c229b0 |
ia64: add support for TIF_NOTIFY_SIGNAL
Wire up TIF_NOTIFY_SIGNAL handling for ia64. Cc: linux-ia64@vger.kernel.org [axboe: added fixes from Mike Rapoport <rppt@kernel.org>] Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Frederic Weisbecker
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8a6a5920d3 |
sched/vtime: Consolidate IRQ time accounting
The 3 architectures implementing CONFIG_VIRT_CPU_ACCOUNTING_NATIVE all have their own version of irq time accounting that dispatch the cputime to the appropriate index: hardirq, softirq, system, idle, guest... from an all-in-one function. Instead of having these ad-hoc versions, move the cputime destination dispatch decision to the core code and leave only the actual per-index cputime accounting to the architecture. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201202115732.27827-4-frederic@kernel.org |
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Peter Zijlstra
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58c644ba51 |
sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.
Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.
(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
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Arnd Bergmann
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2b49ddcef2 |
ia64: convert to legacy_timer_tick
ia64 is the only architecture that calls xtime_update() in a loop,
once for each jiffie that has passed since the last event.
Before commit
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Al Viro
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77f9c902f4 |
[ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea()
In case of positions passed by ptrace_[sg]etregs() to access_uarea() the latter sets the stack unwind up, walks all the way up the stack and proceeds to pass the resulting info to access_elf_reg(). The thing is, we'd *already* obtained that info, so we can bloody well call access_elf_reg() directly. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Al Viro
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3b2d387c5e |
[ia64] missed cleanups from switch to regset coredumps
a bunch of function could've been made static back in 2008 when ia64 switched to regset-based coredumps Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Linus Torvalds
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4a22709e21 |
arch-cleanup-2020-10-22
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Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block
Pull arch task_work cleanups from Jens Axboe:
"Two cleanups that don't fit other categories:
- Finally get the task_work_add() cleanup done properly, so we don't
have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates
all callers, and also fixes up the documentation for
task_work_add().
- While working on some TIF related changes for 5.11, this
TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch
duplication for how that is handled"
* tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block:
task_work: cleanup notification modes
tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
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Minchan Kim
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ecb8ac8b1f |
mm/madvise: introduce process_madvise() syscall: an external memory hinting API
There is usecase that System Management Software(SMS) want to give a
memory hint like MADV_[COLD|PAGEEOUT] to other processes and in the
case of Android, it is the ActivityManagerService.
The information required to make the reclaim decision is not known to the
app. Instead, it is known to the centralized userspace
daemon(ActivityManagerService), and that daemon must be able to initiate
reclaim on its own without any app involvement.
To solve the issue, this patch introduces a new syscall
process_madvise(2). It uses pidfd of an external process to give the
hint. It also supports vector address range because Android app has
thousands of vmas due to zygote so it's totally waste of CPU and power if
we should call the syscall one by one for each vma.(With testing 2000-vma
syscall vs 1-vector syscall, it showed 15% performance improvement. I
think it would be bigger in real practice because the testing ran very
cache friendly environment).
Another potential use case for the vector range is to amortize the cost
ofTLB shootdowns for multiple ranges when using MADV_DONTNEED; this could
benefit users like TCP receive zerocopy and malloc implementations. In
future, we could find more usecases for other advises so let's make it
happens as API since we introduce a new syscall at this moment. With
that, existing madvise(2) user could replace it with process_madvise(2)
with their own pid if they want to have batch address ranges support
feature.
ince it could affect other process's address range, only privileged
process(PTRACE_MODE_ATTACH_FSCREDS) or something else(e.g., being the same
UID) gives it the right to ptrace the process could use it successfully.
The flag argument is reserved for future use if we need to extend the API.
I think supporting all hints madvise has/will supported/support to
process_madvise is rather risky. Because we are not sure all hints make
sense from external process and implementation for the hint may rely on
the caller being in the current context so it could be error-prone. Thus,
I just limited hints as MADV_[COLD|PAGEOUT] in this patch.
If someone want to add other hints, we could hear the usecase and review
it for each hint. It's safer for maintenance rather than introducing a
buggy syscall but hard to fix it later.
So finally, the API is as follows,
ssize_t process_madvise(int pidfd, const struct iovec *iovec,
unsigned long vlen, int advice, unsigned int flags);
DESCRIPTION
The process_madvise() system call is used to give advice or directions
to the kernel about the address ranges from external process as well as
local process. It provides the advice to address ranges of process
described by iovec and vlen. The goal of such advice is to improve
system or application performance.
The pidfd selects the process referred to by the PID file descriptor
specified in pidfd. (See pidofd_open(2) for further information)
The pointer iovec points to an array of iovec structures, defined in
<sys/uio.h> as:
struct iovec {
void *iov_base; /* starting address */
size_t iov_len; /* number of bytes to be advised */
};
The iovec describes address ranges beginning at address(iov_base)
and with size length of bytes(iov_len).
The vlen represents the number of elements in iovec.
The advice is indicated in the advice argument, which is one of the
following at this moment if the target process specified by pidfd is
external.
MADV_COLD
MADV_PAGEOUT
Permission to provide a hint to external process is governed by a
ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2).
The process_madvise supports every advice madvise(2) has if target
process is in same thread group with calling process so user could
use process_madvise(2) to extend existing madvise(2) to support
vector address ranges.
RETURN VALUE
On success, process_madvise() returns the number of bytes advised.
This return value may be less than the total number of requested
bytes, if an error occurred. The caller should check return value
to determine whether a partial advice occurred.
FAQ:
Q.1 - Why does any external entity have better knowledge?
Quote from Sandeep
"For Android, every application (including the special SystemServer)
are forked from Zygote. The reason of course is to share as many
libraries and classes between the two as possible to benefit from the
preloading during boot.
After applications start, (almost) all of the APIs end up calling into
this SystemServer process over IPC (binder) and back to the
application.
In a fully running system, the SystemServer monitors every single
process periodically to calculate their PSS / RSS and also decides
which process is "important" to the user for interactivity.
So, because of how these processes start _and_ the fact that the
SystemServer is looping to monitor each process, it does tend to *know*
which address range of the application is not used / useful.
Besides, we can never rely on applications to clean things up
themselves. We've had the "hey app1, the system is low on memory,
please trim your memory usage down" notifications for a long time[1].
They rely on applications honoring the broadcasts and very few do.
So, if we want to avoid the inevitable killing of the application and
restarting it, some way to be able to tell the OS about unimportant
memory in these applications will be useful.
- ssp
Q.2 - How to guarantee the race(i.e., object validation) between when
giving a hint from an external process and get the hint from the target
process?
process_madvise operates on the target process's address space as it
exists at the instant that process_madvise is called. If the space
target process can run between the time the process_madvise process
inspects the target process address space and the time that
process_madvise is actually called, process_madvise may operate on
memory regions that the calling process does not expect. It's the
responsibility of the process calling process_madvise to close this
race condition. For example, the calling process can suspend the
target process with ptrace, SIGSTOP, or the freezer cgroup so that it
doesn't have an opportunity to change its own address space before
process_madvise is called. Another option is to operate on memory
regions that the caller knows a priori will be unchanged in the target
process. Yet another option is to accept the race for certain
process_madvise calls after reasoning that mistargeting will do no
harm. The suggested API itself does not provide synchronization. It
also apply other APIs like move_pages, process_vm_write.
The race isn't really a problem though. Why is it so wrong to require
that callers do their own synchronization in some manner? Nobody
objects to write(2) merely because it's possible for two processes to
open the same file and clobber each other's writes --- instead, we tell
people to use flock or something. Think about mmap. It never
guarantees newly allocated address space is still valid when the user
tries to access it because other threads could unmap the memory right
before. That's where we need synchronization by using other API or
design from userside. It shouldn't be part of API itself. If someone
needs more fine-grained synchronization rather than process level,
there were two ideas suggested - cookie[2] and anon-fd[3]. Both are
applicable via using last reserved argument of the API but I don't
think it's necessary right now since we have already ways to prevent
the race so don't want to add additional complexity with more
fine-grained optimization model.
To make the API extend, it reserved an unsigned long as last argument
so we could support it in future if someone really needs it.
Q.3 - Why doesn't ptrace work?
Injecting an madvise in the target process using ptrace would not work
for us because such injected madvise would have to be executed by the
target process, which means that process would have to be runnable and
that creates the risk of the abovementioned race and hinting a wrong
VMA. Furthermore, we want to act the hint in caller's context, not the
callee's, because the callee is usually limited in cpuset/cgroups or
even freezed state so they can't act by themselves quick enough, which
causes more thrashing/kill. It doesn't work if the target process are
ptraced(e.g., strace, debugger, minidump) because a process can have at
most one ptracer.
[1] https://developer.android.com/topic/performance/memory"
[2] process_getinfo for getting the cookie which is updated whenever
vma of process address layout are changed - Daniel Colascione -
https://lore.kernel.org/lkml/20190520035254.57579-1-minchan@kernel.org/T/#m7694416fd179b2066a2c62b5b139b14e3894e224
[3] anonymous fd which is used for the object(i.e., address range)
validation - Michal Hocko -
https://lore.kernel.org/lkml/20200120112722.GY18451@dhcp22.suse.cz/
[minchan@kernel.org: fix process_madvise build break for arm64]
Link: http://lkml.kernel.org/r/20200303145756.GA219683@google.com
[minchan@kernel.org: fix build error for mips of process_madvise]
Link: http://lkml.kernel.org/r/20200508052517.GA197378@google.com
[akpm@linux-foundation.org: fix patch ordering issue]
[akpm@linux-foundation.org: fix arm64 whoops]
[minchan@kernel.org: make process_madvise() vlen arg have type size_t, per Florian]
[akpm@linux-foundation.org: fix i386 build]
[sfr@canb.auug.org.au: fix syscall numbering]
Link: https://lkml.kernel.org/r/20200905142639.49fc3f1a@canb.auug.org.au
[sfr@canb.auug.org.au: madvise.c needs compat.h]
Link: https://lkml.kernel.org/r/20200908204547.285646b4@canb.auug.org.au
[minchan@kernel.org: fix mips build]
Link: https://lkml.kernel.org/r/20200909173655.GC2435453@google.com
[yuehaibing@huawei.com: remove duplicate header which is included twice]
Link: https://lkml.kernel.org/r/20200915121550.30584-1-yuehaibing@huawei.com
[minchan@kernel.org: do not use helper functions for process_madvise]
Link: https://lkml.kernel.org/r/20200921175539.GB387368@google.com
[akpm@linux-foundation.org: pidfd_get_pid() gained an argument]
[sfr@canb.auug.org.au: fix up for "iov_iter: transparently handle compat iovecs in import_iovec"]
Link: https://lkml.kernel.org/r/20200928212542.468e1fef@canb.auug.org.au
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Daniel Colascione <dancol@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Dias <joaodias@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: <linux-man@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200302193630.68771-3-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200508183320.GA125527@google.com
Link: http://lkml.kernel.org/r/20200622192900.22757-4-minchan@kernel.org
Link: https://lkml.kernel.org/r/20200901000633.1920247-4-minchan@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
Krzysztof Kozlowski
|
7404840d87 |
ia64: fix build error with !COREDUMP
Fix linkage error when CONFIG_BINFMT_ELF is selected but CONFIG_COREDUMP
is not:
ia64-linux-ld: arch/ia64/kernel/elfcore.o: in function `elf_core_write_extra_phdrs':
elfcore.c:(.text+0x172): undefined reference to `dump_emit'
ia64-linux-ld: arch/ia64/kernel/elfcore.o: in function `elf_core_write_extra_data':
elfcore.c:(.text+0x2b2): undefined reference to `dump_emit'
Fixes:
|
||
|
Jens Axboe
|
3c532798ec |
tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
All the callers currently do this, clean it up and move the clearing into tracehook_notify_resume() instead. Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
|
Linus Torvalds
|
5a32c3413d |
dma-mapping updates for 5.10
- rework the non-coherent DMA allocator
- move private definitions out of <linux/dma-mapping.h>
- lower CMA_ALIGNMENT (Paul Cercueil)
- remove the omap1 dma address translation in favor of the common
code
- make dma-direct aware of multiple dma offset ranges (Jim Quinlan)
- support per-node DMA CMA areas (Barry Song)
- increase the default seg boundary limit (Nicolin Chen)
- misc fixes (Robin Murphy, Thomas Tai, Xu Wang)
- various cleanups
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Merge tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- rework the non-coherent DMA allocator
- move private definitions out of <linux/dma-mapping.h>
- lower CMA_ALIGNMENT (Paul Cercueil)
- remove the omap1 dma address translation in favor of the common code
- make dma-direct aware of multiple dma offset ranges (Jim Quinlan)
- support per-node DMA CMA areas (Barry Song)
- increase the default seg boundary limit (Nicolin Chen)
- misc fixes (Robin Murphy, Thomas Tai, Xu Wang)
- various cleanups
* tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits)
ARM/ixp4xx: add a missing include of dma-map-ops.h
dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling
dma-direct: factor out a dma_direct_alloc_from_pool helper
dma-direct check for highmem pages in dma_direct_alloc_pages
dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h>
dma-mapping: move large parts of <linux/dma-direct.h> to kernel/dma
dma-mapping: move dma-debug.h to kernel/dma/
dma-mapping: remove <asm/dma-contiguous.h>
dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h>
dma-contiguous: remove dma_contiguous_set_default
dma-contiguous: remove dev_set_cma_area
dma-contiguous: remove dma_declare_contiguous
dma-mapping: split <linux/dma-mapping.h>
cma: decrease CMA_ALIGNMENT lower limit to 2
firewire-ohci: use dma_alloc_pages
dma-iommu: implement ->alloc_noncoherent
dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods
dma-mapping: add a new dma_alloc_pages API
dma-mapping: remove dma_cache_sync
53c700: convert to dma_alloc_noncoherent
...
|
||
|
Linus Torvalds
|
612e7a4c16 |
kernel-clone-v5.9
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCXz5bNAAKCRCRxhvAZXjc opfjAP9R/J72yxdd2CLGNZ96hyiRX1NgFDOVUhscOvujYJf8ZwD+OoLmKMvAyFW6 hnMhT1n9Q+aq194hyzChOLQaBTejBQ8= =4WCX -----END PGP SIGNATURE----- Merge tag 'kernel-clone-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull kernel_clone() updates from Christian Brauner: "During the v5.9 merge window we reworked the process creation codepaths across multiple architectures. After this work we were only left with the _do_fork() helper based on the struct kernel_clone_args calling convention. As was pointed out _do_fork() isn't valid kernelese especially for a helper that isn't just static. This series removes the _do_fork() helper and introduces the new kernel_clone() helper. The process creation cleanup didn't change the name to something more reasonable mainly because _do_fork() was used in quite a few places. So sending this as a separate series seemed the better strategy. I originally intended to send this early in the v5.9 development cycle after the merge window had closed but given that this was touching quite a few places I decided to defer this until the v5.10 merge window" * tag 'kernel-clone-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: sched: remove _do_fork() tracing: switch to kernel_clone() kgdbts: switch to kernel_clone() kprobes: switch to kernel_clone() x86: switch to kernel_clone() sparc: switch to kernel_clone() nios2: switch to kernel_clone() m68k: switch to kernel_clone() ia64: switch to kernel_clone() h8300: switch to kernel_clone() fork: introduce kernel_clone() |
||
|
Linus Torvalds
|
ced3a9eb3c |
Cleanups by Christoph
1) Switch to libata instead of legacy ide driver 2) Drop ia64 perfmon (it's been broken for a while) -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQQW3WBGcnu5yJnSXn0kTJLX0iGMLAUCX4S06RQcdG9ueS5sdWNr QGludGVsLmNvbQAKCRAkTJLX0iGMLIIsAP9DStFhvOKJoGws8PJUaiq3jBQqNNSA pPrOguYSp8iTQQEA3+ce+2thQQH+MLn1aqTBSzo/RqukZhRwrVtUxqDW4gc= =AEew -----END PGP SIGNATURE----- Merge tag 'ia64_for_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux Pull ia64 updates from Tony Luck: "Cleanups by Christoph: - Switch to libata instead of legacy ide driver - Drop ia64 perfmon (it's been broken for a while)" * tag 'ia64_for_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: ia64: Use libata instead of the legacy ide driver in defconfigs ia64: Remove perfmon |
||
|
Linus Torvalds
|
1c6890707e |
This tree prepares to unify the kretprobe trampoline handler and make
kretprobe lockless. (Those patches are still work in progress.) Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAl+EgmMRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1hKQg//WrYVMc+lLG+QP4IuKfolZVGNeS60crZE mTvs4iX8gBrU5omrgatrjUiDhrln6MiTf6H0ec072BAho91lom/AlyDUQbta5sls uXKzIjHe9J7ca+myXGDiXkGmWXgcBYHBHifyzf04xhPyFXH869HLxFXCHeV1S3m7 Tga1Lceths425t8nnYb9yao9k26l22BSklzPqEM/XNNnktrMiaiYlfgUxi1g3hMj v9IbZy43qpzljyrnfRk/tRGMnZ/BtZpj7swQEjUVOKgmcymX6bQoxqYvpAH5mYX7 jqKcTLsw/Jm4YhZdeBpjZc2JNQkNJSLjiXMMtQTmncPKx2shuU1s4KhgRtYEEeyI BO37k3RwplED7/yBJtojNt0WWYfd7X2ee8SPuSW/VPL6jSDgJii3Um0AldPZ0J3g 72OT4rJkyqFER0ZKSf8uIym2Zi7F5IvtzK2xJAzquOQlYdCaKSNrWurckOzWHMm9 JKqUqq3nV4mFUKEE7Kf0Nu3UgQZNKpxUNepWBoJb3j6baK32Qgb6qpNLLPTTi2qJ AwxicRlr7jzdyP2cwvU5z2FuilPypOob8ZnowhhIyV+4xQY9CymJ3uluXattDC74 ZNgydTyyYCo0PwYZGUDeE8o87apYd3+sEOErLtw4CjaoiadxDaMBmfsHzU7W29Rc Fow4+FQCK/Y= =2jY/ -----END PGP SIGNATURE----- Merge tag 'perf-kprobes-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf/kprobes updates from Ingo Molnar: "This prepares to unify the kretprobe trampoline handler and make kretprobe lockless (those patches are still work in progress)" * tag 'perf-kprobes-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix to check probe enabled before disarm_kprobe_ftrace() kprobes: Make local functions static kprobes: Free kretprobe_instance with RCU callback kprobes: Remove NMI context check sparc: kprobes: Use generic kretprobe trampoline handler sh: kprobes: Use generic kretprobe trampoline handler s390: kprobes: Use generic kretprobe trampoline handler powerpc: kprobes: Use generic kretprobe trampoline handler parisc: kprobes: Use generic kretprobe trampoline handler mips: kprobes: Use generic kretprobe trampoline handler ia64: kprobes: Use generic kretprobe trampoline handler csky: kprobes: Use generic kretprobe trampoline handler arc: kprobes: Use generic kretprobe trampoline handler arm64: kprobes: Use generic kretprobe trampoline handler arm: kprobes: Use generic kretprobe trampoline handler x86/kprobes: Use generic kretprobe trampoline handler kprobes: Add generic kretprobe trampoline handler |
||
|
Linus Torvalds
|
34eb62d868 |
Orphan link sections were a long-standing source of obscure bugs,
because the heuristics that various linkers & compilers use to handle them (include these bits into the output image vs discarding them silently) are both highly idiosyncratic and also version dependent. Instead of this historically problematic mess, this tree by Kees Cook (et al) adds build time asserts and build time warnings if there's any orphan section in the kernel or if a section is not sized as expected. And because we relied on so many silent assumptions in this area, fix a metric ton of dependencies and some outright bugs related to this, before we can finally enable the checks on the x86, ARM and ARM64 platforms. Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAl+Edv4RHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1hiKBAApdJEOaK7hMc3013DYNctklIxEPJL2mFJ 11YJRIh4pUJTF0TE+EHT/D+rSIuRsyuoSmOQBQ61/wVSnyG067GjjVJRqh/eYaJ1 fDhJi2FuHOjXl+CiN0KxzBjjp+V4NhF7jHT59tpQSvfZeg7FjteoxfztxaCp5ek3 S3wHB3CC4c4jE3lfjHem1E9/PwT4kwPYx1c3gAUdEqJdjkihjX9fWusfjLeqW6/d Y5VkApi6bL9XiZUZj5l0dEIweLJJ86+PkKJqpo3spxxEak1LSn1MEix+lcJ8e1Kg sb/bEEivDcmFlFWOJnn0QLquCR0Cx5bz1pwsL0tuf0yAd4+sXX5IMuGUysZlEdKM BHL9h5HbevGF4BScwZwZH7lyEg7q67s5KnRu4hxy0Swfcj7y0oT/9lXqpbpZ2DqO Hd+bRRQKIbqnTMp0hcit9LfpLp93vj0dBlaV5ocAJJlu62u9VnwGG5HQuZ5giLUr kA1SLw63Y1wopFRxgFyER8les7eLsu0zxHeK44rRVlVnfI99OMTOgVNicmDFy3Fm AfcnfJG0BqBEJGQz5es34uQQKKBwFPtC9NztopI62KiwOspYYZyrO1BNxdOc6DlS mIHrmO89HMXuid5eolvLaFqUWirHoWO8TlycgZxUWVHc2txVPjAEU/axouU/dSSU w/6GpzAa+7g= =fXAw -----END PGP SIGNATURE----- Merge tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull orphan section checking from Ingo Molnar: "Orphan link sections were a long-standing source of obscure bugs, because the heuristics that various linkers & compilers use to handle them (include these bits into the output image vs discarding them silently) are both highly idiosyncratic and also version dependent. Instead of this historically problematic mess, this tree by Kees Cook (et al) adds build time asserts and build time warnings if there's any orphan section in the kernel or if a section is not sized as expected. And because we relied on so many silent assumptions in this area, fix a metric ton of dependencies and some outright bugs related to this, before we can finally enable the checks on the x86, ARM and ARM64 platforms" * tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/boot/compressed: Warn on orphan section placement x86/build: Warn on orphan section placement arm/boot: Warn on orphan section placement arm/build: Warn on orphan section placement arm64/build: Warn on orphan section placement x86/boot/compressed: Add missing debugging sections to output x86/boot/compressed: Remove, discard, or assert for unwanted sections x86/boot/compressed: Reorganize zero-size section asserts x86/build: Add asserts for unwanted sections x86/build: Enforce an empty .got.plt section x86/asm: Avoid generating unused kprobe sections arm/boot: Handle all sections explicitly arm/build: Assert for unwanted sections arm/build: Add missing sections arm/build: Explicitly keep .ARM.attributes sections arm/build: Refactor linker script headers arm64/build: Assert for unwanted sections arm64/build: Add missing DWARF sections arm64/build: Use common DISCARDS in linker script arm64/build: Remove .eh_frame* sections due to unwind tables ... |
||
Christoph Hellwig
|
0a0f0d8be7 |
dma-mapping: split <linux/dma-mapping.h>
Split out all the bits that are purely for dma_map_ops implementations and related code into a new <linux/dma-map-ops.h> header so that they don't get pulled into all the drivers. That also means the architecture specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h> any more, which leads to a missing includes that were pulled in by the x86 or arm versions in a few not overly portable drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> |
||
|
Christoph Hellwig
|
8c1c6c7588 |
Merge branch 'master' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into dma-mapping-for-next
Pull in the latest 5.9 tree for the commit to revert the V4L2_FLAG_MEMORY_NON_CONSISTENT uapi addition. |
||
|
Christoph Hellwig
|
ecf5b72d5f |
ia64: Remove perfmon
perfmon has been marked broken and thus been disabled for all builds for more than two years. Remove it entirely. Cc: Anant Thazhemadam <anant.thazhemadam@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Enthusiastically-ACKed-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/20200911094920.1173631-1-hch@lst.de |
||
|
Christoph Hellwig
|
abdaf11ac1 |
dma-mapping: add (back) arch_dma_mark_clean for ia64
Add back a hook to optimize dcache flushing after reading executable code using DMA. This gets ia64 out of the business of pretending to be dma incoherent just for this optimization. Signed-off-by: Christoph Hellwig <hch@lst.de> |
||
Masami Hiramatsu
|
e792ff804f |
ia64: kprobes: Use generic kretprobe trampoline handler
Use the generic kretprobe trampoline handler. Don't use framepointer verification. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/159870606883.1229682.12331813108378725668.stgit@devnote2 |
||
Randy Dunlap
|
5f7b81c183 |
ia64: fix min_low_pfn/max_low_pfn build errors
Fix min_low_pfn/max_low_pfn build errors for arch/ia64/: (e.g.) ERROR: "max_low_pfn" [drivers/rpmsg/virtio_rpmsg_bus.ko] undefined! ERROR: "min_low_pfn" [drivers/rpmsg/virtio_rpmsg_bus.ko] undefined! ERROR: "min_low_pfn" [drivers/hwtracing/intel_th/intel_th_msu.ko] undefined! ERROR: "max_low_pfn" [drivers/hwtracing/intel_th/intel_th_msu.ko] undefined! ERROR: "min_low_pfn" [drivers/crypto/cavium/nitrox/n5pf.ko] undefined! ERROR: "max_low_pfn" [drivers/crypto/cavium/nitrox/n5pf.ko] undefined! ERROR: "max_low_pfn" [drivers/md/dm-integrity.ko] undefined! ERROR: "min_low_pfn" [drivers/md/dm-integrity.ko] undefined! ERROR: "max_low_pfn" [crypto/tcrypt.ko] undefined! ERROR: "min_low_pfn" [crypto/tcrypt.ko] undefined! ERROR: "min_low_pfn" [security/keys/encrypted-keys/encrypted-keys.ko] undefined! ERROR: "max_low_pfn" [security/keys/encrypted-keys/encrypted-keys.ko] undefined! ERROR: "min_low_pfn" [arch/ia64/kernel/mca_recovery.ko] undefined! ERROR: "max_low_pfn" [arch/ia64/kernel/mca_recovery.ko] undefined! David suggested just exporting min_low_pfn & max_low_pfn in mm/memblock.c: https://lore.kernel.org/lkml/alpine.DEB.2.22.394.2006291911220.1118534@chino.kir.corp.google.com/ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: linux-ia64@vger.kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> |
||
Kees Cook
|
c604abc3f6 |
vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG
The .comment section doesn't belong in STABS_DEBUG. Split it out into a new macro named ELF_DETAILS. This will gain other non-debug sections that need to be accounted for when linking with --orphan-handling=warn. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-arch@vger.kernel.org Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org |
||
Gustavo A. R. Silva
|
df561f6688 |
treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> |
||
Christian Brauner
|
f8c40ebe65
|
ia64: switch to kernel_clone()
The old _do_fork() helper is removed in favor of the new kernel_clone() helper. The latter adheres to naming conventions for kernel internal syscall helpers. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: linux-ia64@vger.kernel.org Link: https://lore.kernel.org/r/20200819104655.436656-4-christian.brauner@ubuntu.com |
||
Xiaoming Ni
|
88db0aa242 |
all arch: remove system call sys_sysctl
Since commit
|
||
|
Linus Torvalds
|
97d052ea3f |
A set of locking fixes and updates:
- Untangle the header spaghetti which causes build failures in various
situations caused by the lockdep additions to seqcount to validate that
the write side critical sections are non-preemptible.
- The seqcount associated lock debug addons which were blocked by the
above fallout.
seqcount writers contrary to seqlock writers must be externally
serialized, which usually happens via locking - except for strict per
CPU seqcounts. As the lock is not part of the seqcount, lockdep cannot
validate that the lock is held.
This new debug mechanism adds the concept of associated locks.
sequence count has now lock type variants and corresponding
initializers which take a pointer to the associated lock used for
writer serialization. If lockdep is enabled the pointer is stored and
write_seqcount_begin() has a lockdep assertion to validate that the
lock is held.
Aside of the type and the initializer no other code changes are
required at the seqcount usage sites. The rest of the seqcount API is
unchanged and determines the type at compile time with the help of
_Generic which is possible now that the minimal GCC version has been
moved up.
Adding this lockdep coverage unearthed a handful of seqcount bugs which
have been addressed already independent of this.
While generaly useful this comes with a Trojan Horse twist: On RT
kernels the write side critical section can become preemtible if the
writers are serialized by an associated lock, which leads to the well
known reader preempts writer livelock. RT prevents this by storing the
associated lock pointer independent of lockdep in the seqcount and
changing the reader side to block on the lock when a reader detects
that a writer is in the write side critical section.
- Conversion of seqcount usage sites to associated types and initializers.
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Merge tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Thomas Gleixner:
"A set of locking fixes and updates:
- Untangle the header spaghetti which causes build failures in
various situations caused by the lockdep additions to seqcount to
validate that the write side critical sections are non-preemptible.
- The seqcount associated lock debug addons which were blocked by the
above fallout.
seqcount writers contrary to seqlock writers must be externally
serialized, which usually happens via locking - except for strict
per CPU seqcounts. As the lock is not part of the seqcount, lockdep
cannot validate that the lock is held.
This new debug mechanism adds the concept of associated locks.
sequence count has now lock type variants and corresponding
initializers which take a pointer to the associated lock used for
writer serialization. If lockdep is enabled the pointer is stored
and write_seqcount_begin() has a lockdep assertion to validate that
the lock is held.
Aside of the type and the initializer no other code changes are
required at the seqcount usage sites. The rest of the seqcount API
is unchanged and determines the type at compile time with the help
of _Generic which is possible now that the minimal GCC version has
been moved up.
Adding this lockdep coverage unearthed a handful of seqcount bugs
which have been addressed already independent of this.
While generally useful this comes with a Trojan Horse twist: On RT
kernels the write side critical section can become preemtible if
the writers are serialized by an associated lock, which leads to
the well known reader preempts writer livelock. RT prevents this by
storing the associated lock pointer independent of lockdep in the
seqcount and changing the reader side to block on the lock when a
reader detects that a writer is in the write side critical section.
- Conversion of seqcount usage sites to associated types and
initializers"
* tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
locking/seqlock, headers: Untangle the spaghetti monster
locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header
x86/headers: Remove APIC headers from <asm/smp.h>
seqcount: More consistent seqprop names
seqcount: Compress SEQCNT_LOCKNAME_ZERO()
seqlock: Fold seqcount_LOCKNAME_init() definition
seqlock: Fold seqcount_LOCKNAME_t definition
seqlock: s/__SEQ_LOCKDEP/__SEQ_LOCK/g
hrtimer: Use sequence counter with associated raw spinlock
kvm/eventfd: Use sequence counter with associated spinlock
userfaultfd: Use sequence counter with associated spinlock
NFSv4: Use sequence counter with associated spinlock
iocost: Use sequence counter with associated spinlock
raid5: Use sequence counter with associated spinlock
vfs: Use sequence counter with associated spinlock
timekeeping: Use sequence counter with associated raw spinlock
xfrm: policy: Use sequence counters with associated lock
netfilter: nft_set_rbtree: Use sequence counter with associated rwlock
netfilter: conntrack: Use sequence counter with associated spinlock
sched: tasks: Use sequence counter with associated spinlock
...
|
||
|
Linus Torvalds
|
8d3e09b433 |
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull regset conversion fix from Al Viro: "Fix a regression from an unnoticed bisect hazard in the regset series. A bunch of old (aout, originally) primitives used by coredumps became dead code after fdpic conversion to regsets. Removal of that dead code had been the first commit in the followups to regset series; unfortunately, it happened to hide the bisect hazard on sh (extern for fpregs_get() had not been updated in the main series when it should have been; followup simply made fpregs_get() static). And without that followup commit this bisect hazard became breakage in the mainline" Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill unused dump_fpu() instances |
||
|
Linus Torvalds
|
81e11336d9 |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
|
||
Mike Rapoport
|
ca15ca406f |
mm: remove unneeded includes of <asm/pgalloc.h>
Patch series "mm: cleanup usage of <asm/pgalloc.h>"
Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table. These patches add
generic versions of these functions in <asm-generic/pgalloc.h> and enable
use of the generic functions where appropriate.
In addition, functions declared and defined in <asm/pgalloc.h> headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the <asm/pgalloc.h> included all over the place.
The first patch in this series removes unneeded includes of
<asm/pgalloc.h>
In the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.
This patch (of 8):
In most cases <asm/pgalloc.h> header is required only for allocations of
page table memory. Most of the .c files that include that header do not
use symbols declared in <asm/pgalloc.h> and do not require that header.
As for the other header files that used to include <asm/pgalloc.h>, it is
possible to move that include into the .c file that actually uses symbols
from <asm/pgalloc.h> and drop the include from the header file.
The process was somewhat automated using
sed -i -E '/[<"]asm\/pgalloc\.h/d' \
$(grep -L -w -f /tmp/xx \
$(git grep -E -l '[<"]asm/pgalloc\.h'))
where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.
[rppt@linux.ibm.com: fix powerpc warning]
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Linus Torvalds
|
19b39c38ab |
Merge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ptrace regset updates from Al Viro:
"Internal regset API changes:
- regularize copy_regset_{to,from}_user() callers
- switch to saner calling conventions for ->get()
- kill user_regset_copyout()
The ->put() side of things will have to wait for the next cycle,
unfortunately.
The balance is about -1KLoC and replacements for ->get() instances are
a lot saner"
* 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
regset: kill user_regset_copyout{,_zero}()
regset(): kill ->get_size()
regset: kill ->get()
csky: switch to ->regset_get()
xtensa: switch to ->regset_get()
parisc: switch to ->regset_get()
nds32: switch to ->regset_get()
nios2: switch to ->regset_get()
hexagon: switch to ->regset_get()
h8300: switch to ->regset_get()
openrisc: switch to ->regset_get()
riscv: switch to ->regset_get()
c6x: switch to ->regset_get()
ia64: switch to ->regset_get()
arc: switch to ->regset_get()
arm: switch to ->regset_get()
sh: convert to ->regset_get()
arm64: switch to ->regset_get()
mips: switch to ->regset_get()
sparc: switch to ->regset_get()
...
|
||
|
Peter Zijlstra
|
b3545192e2 |
locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header
We want to remove the #include <asm/io.h> from <asm/smp.h>, but for this we have to move the XTP bits into a separate header first (as these bits rely on <asm/io.h> definitions), and include them in the .c files that rely on those APIs. Co-developed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Linus Torvalds
|
4f30a60aa7 |
close-range-v5.9
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Merge tag 'close-range-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull close_range() implementation from Christian Brauner:
"This adds the close_range() syscall. It allows to efficiently close a
range of file descriptors up to all file descriptors of a calling
task.
This is coordinated with the FreeBSD folks which have copied our
version of this syscall and in the meantime have already merged it in
April 2019:
https://reviews.freebsd.org/D21627
https://svnweb.freebsd.org/base?view=revision&revision=359836
The syscall originally came up in a discussion around the new mount
API and making new file descriptor types cloexec by default. During
this discussion, Al suggested the close_range() syscall.
First, it helps to close all file descriptors of an exec()ing task.
This can be done safely via (quoting Al's example from [1] verbatim):
/* that exec is sensitive */
unshare(CLONE_FILES);
/* we don't want anything past stderr here */
close_range(3, ~0U);
execve(....);
The code snippet above is one way of working around the problem that
file descriptors are not cloexec by default. This is aggravated by the
fact that we can't just switch them over without massively regressing
userspace. For a whole class of programs having an in-kernel method of
closing all file descriptors is very helpful (e.g. demons, service
managers, programming language standard libraries, container managers
etc.).
Second, it allows userspace to avoid implementing closing all file
descriptors by parsing through /proc/<pid>/fd/* and calling close() on
each file descriptor and other hacks. From looking at various
large(ish) userspace code bases this or similar patterns are very
common in service managers, container runtimes, and programming
language runtimes/standard libraries such as Python or Rust.
In addition, the syscall will also work for tasks that do not have
procfs mounted and on kernels that do not have procfs support compiled
in. In such situations the only way to make sure that all file
descriptors are closed is to call close() on each file descriptor up
to UINT_MAX or RLIMIT_NOFILE, OPEN_MAX trickery.
Based on Linus' suggestion close_range() also comes with a new flag
CLOSE_RANGE_UNSHARE to more elegantly handle file descriptor dropping
right before exec. This would usually be expressed in the sequence:
unshare(CLONE_FILES);
close_range(3, ~0U);
as pointed out by Linus it might be desirable to have this be a part
of close_range() itself under a new flag CLOSE_RANGE_UNSHARE which
gets especially handy when we're closing all file descriptors above a
certain threshold.
Test-suite as always included"
* tag 'close-range-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
tests: add CLOSE_RANGE_UNSHARE tests
close_range: add CLOSE_RANGE_UNSHARE
tests: add close_range() tests
arch: wire-up close_range()
open: add close_range()
|
||
|
Linus Torvalds
|
9ba27414f2 |
fork-v5.9
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Merge tag 'fork-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull fork cleanups from Christian Brauner:
"This is cleanup series from when we reworked a chunk of the process
creation paths in the kernel and switched to struct
{kernel_}clone_args.
High-level this does two main things:
- Remove the double export of both do_fork() and _do_fork() where
do_fork() used the incosistent legacy clone calling convention.
Now we only export _do_fork() which is based on struct
kernel_clone_args.
- Remove the copy_thread_tls()/copy_thread() split making the
architecture specific HAVE_COYP_THREAD_TLS config option obsolete.
This switches all remaining architectures to select
HAVE_COPY_THREAD_TLS and thus to the copy_thread_tls() calling
convention. The current split makes the process creation codepaths
more convoluted than they need to be. Each architecture has their own
copy_thread() function unless it selects HAVE_COPY_THREAD_TLS then it
has a copy_thread_tls() function.
The split is not needed anymore nowadays, all architectures support
CLONE_SETTLS but quite a few of them never bothered to select
HAVE_COPY_THREAD_TLS and instead simply continued to use copy_thread()
and use the old calling convention. Removing this split cleans up the
process creation codepaths and paves the way for implementing clone3()
on such architectures since it requires the copy_thread_tls() calling
convention.
After having made each architectures support copy_thread_tls() this
series simply renames that function back to copy_thread(). It also
switches all architectures that call do_fork() directly over to
_do_fork() and the struct kernel_clone_args calling convention. This
is a corollary of switching the architectures that did not yet support
it over to copy_thread_tls() since do_fork() is conditional on not
supporting copy_thread_tls() (Mostly because it lacks a separate
argument for tls which is trivial to fix but there's no need for this
function to exist.).
The do_fork() removal is in itself already useful as it allows to to
remove the export of both do_fork() and _do_fork() we currently have
in favor of only _do_fork(). This has already been discussed back when
we added clone3(). The legacy clone() calling convention is - as is
probably well-known - somewhat odd:
#
# ABI hall of shame
#
config CLONE_BACKWARDS
config CLONE_BACKWARDS2
config CLONE_BACKWARDS3
that is aggravated by the fact that some architectures such as sparc
follow the CLONE_BACKWARDSx calling convention but don't really select
the corresponding config option since they call do_fork() directly.
So do_fork() enforces a somewhat arbitrary calling convention in the
first place that doesn't really help the individual architectures that
deviate from it. They can thus simply be switched to _do_fork()
enforcing a single calling convention. (I really hope that any new
architectures will __not__ try to implement their own calling
conventions...)
Most architectures already have made a similar switch (m68k comes to
mind).
Overall this removes more code than it adds even with a good portion
of added comments. It simplifies a chunk of arch specific assembly
either by moving the code into C or by simply rewriting the assembly.
Architectures that have been touched in non-trivial ways have all been
actually boot and stress tested: sparc and ia64 have been tested with
Debian 9 images. They are the two architectures which have been
touched the most. All non-trivial changes to architectures have seen
acks from the relevant maintainers. nios2 with a custom built
buildroot image. h8300 I couldn't get something bootable to test on
but the changes have been fairly automatic and I'm sure we'll hear
people yell if I broke something there.
All other architectures that have been touched in trivial ways have
been compile tested for each single patch of the series via git rebase
-x "make ..." v5.8-rc2. arm{64} and x86{_64} have been boot tested
even though they have just been trivially touched (removal of the
HAVE_COPY_THREAD_TLS macro from their Kconfig) because well they are
basically "core architectures" and since it is trivial to get your
hands on a useable image"
* tag 'fork-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
arch: rename copy_thread_tls() back to copy_thread()
arch: remove HAVE_COPY_THREAD_TLS
unicore: switch to copy_thread_tls()
sh: switch to copy_thread_tls()
nds32: switch to copy_thread_tls()
microblaze: switch to copy_thread_tls()
hexagon: switch to copy_thread_tls()
c6x: switch to copy_thread_tls()
alpha: switch to copy_thread_tls()
fork: remove do_fork()
h8300: select HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
nios2: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
sparc: unconditionally enable HAVE_COPY_THREAD_TLS
sparc: share process creation helpers between sparc and sparc64
sparc64: enable HAVE_COPY_THREAD_TLS
fork: fold legacy_clone_args_valid() into _do_fork()
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Al Viro
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bb1a773d5b |
kill unused dump_fpu() instances
dump_fpu() is used only on the architectures that support elf and have neither CORE_DUMP_USE_REGSET nor ELF_CORE_COPY_FPREGS defined. Currently that's csky, m68k, microblaze, nds32 and unicore32. The rest of the instances are dead code. NB: THIS MUST GO AFTER ELF_FDPIC CONVERSION Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Al Viro
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4ff8a356da |
ia64: switch to ->regset_get()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Kees Cook
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3f649ab728 |
treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org> |
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Christian Brauner
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714acdbd1c
|
arch: rename copy_thread_tls() back to copy_thread()
Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls() back simply copy_thread(). It's a simpler name, and doesn't imply that only tls is copied here. This finishes an outstanding chunk of internal process creation work since we've added clone3(). Cc: linux-arch@vger.kernel.org Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>A Acked-by: Stafford Horne <shorne@gmail.com> Acked-by: Greentime Hu <green.hu@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>A Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> |
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Al Viro
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e3fdfa37a3 |
[ia64] access_uarea(): don't bother with fpregs_[gs]et()
similar to previous commit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Al Viro
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6bc4f16c6c |
[ia64] access_uarea(): stop bothering with gpregs_[gs]et()
We know this won't be called for child == current, so we don't need to bother with callbacks, etc. - just do unw_init_from_blocked_task(), unw_unwind_to_user() and do the payload of gpregs_[gs]et(). For one register. Which is to say, access_elf_reg(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Al Viro
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a79ca8e7b9 |
[ia64] regularize do_gpregs_[gs]et()
now access_elf_reg() does the right thing for everything other than r0, we can simplify do_grepgs_[gs]et() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Al Viro
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e2115cf3cc |
[ia64] teach elf_access_reg() to handle the missing range (r16..r31)
Now it's easy to make elf_access_gpreg() handle the rest of global registers (r16..r31). That gets rid of the hole in the registers elf_access_reg() can handle, which will allow to simplify its callers later in the series. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Al Viro
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4c35bf3ae9 |
[ia64] sanitize elf_access_gpreg()
The function takes the register number, finds the corresponding field of pt_regs for registers that are saved there or does the unwind for the registers that end up spilled on the kernel stack. Then it reads from or writes to the resulting location. Unfortunately, finding the required pt_regs field is done by rather horrible switch. It's microoptimized in all the wrong places - it even uses the knowledge that fields for r8..r11 follow each other in pt_regs layout, while r12..r13 are not adjacent to those, etc. All of that is to encode the mapping from register numbers to offsets + the information that r4..r7 are not to be found in pt_regs. It's deeply in nasal demon territory, at that - the games it plays with pointer arithmetics on addresses of structure members are undefined behaviour. Valid C ends up with better code in this case: just initialize a constant array with offsets of relevant pt_regs fields and we don't need that switch anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Christian Brauner
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ddb815bd54
|
ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
This is part of a larger series that aims at getting rid of the
copy_thread()/copy_thread_tls() split that makes the process creation
codepaths in the kernel more convoluted and error-prone than they need
to be.
I'm converting all the remaining arches that haven't yet switched and
am collecting individual acks. Once I have them, I'll send the whole series
removing the copy_thread()/copy_thread_tls() split, the
HAVE_COPY_THREAD_TLS define and the legacy do_fork() helper. The only
kernel-wide process creation entry point for anything not going directly
through the syscall path will then be based on struct kernel_clone_args.
No more danger of weird process creation abi quirks between architectures
hopefully, and easier to maintain overall.
It also unblocks implementing clone3() on architectures not support
copy_thread_tls(). Any architecture that wants to implement clone3()
will need to select HAVE_COPY_THREAD_TLS and thus need to implement
copy_thread_tls(). So both goals are connected but independently
beneficial.
HAVE_COPY_THREAD_TLS means that a given architecture supports
CLONE_SETTLS and not setting it should usually mean that the
architectures doesn't implement it but that's not how things are. In
fact all architectures support CLONE_TLS it's just that they don't
follow the calling convention that HAVE_COPY_THREAD_TLS implies. That
means all architectures can be switched over to select
HAVE_COPY_THREAD_TLS. Once that is done we can remove that macro (yay,
less code), the unnecessary do_fork() export in kernel/fork.c, and also
rename copy_thread_tls() back to copy_thread(). At this point
copy_thread() becomes the main architecture specific part of process
creation but it will be the same layout and calling convention for all
architectures. (Once that is done we can probably cleanup each
copy_thread() function even more but that's for the future.)
Since ia64 does support CLONE_SETTLS there's no reason to not select
HAVE_COPY_THREAD_TLS. This brings us one step closer to getting rid of
the copy_thread()/copy_thread_tls() split we still have and ultimately
the HAVE_COPY_THREAD_TLS define in general. A lot of architectures have
already converted and ia64 is one of the few hat haven't yet. This also
unblocks implementing the clone3() syscall on ia64. Once that is done we
can get of another ARCH_WANTS_* macro.
Once Any architecture that supports HAVE_COPY_THREAD_TLS cannot call the
do_fork() helper anymore. This is fine and intended since it should be
removed in favor of the new, cleaner _do_fork() calling convention based
on struct kernel_clone_args. In fact, most architectures have already
switched. With this patch, ia64 joins the other arches which can't use
the fork(), vfork(), clone(), clone3() syscalls directly and who follow
the new process creation calling convention that is based on struct
kernel_clone_args which we introduced a while back. This means less
custom assembly in the architectures entry path to set up the registers
before calling into the process creation helper and it is easier to to
support new features without having to adapt calling conventions. It
also unifies all process creation paths between fork(), vfork(),
clone(), and clone3(). (We can't fix the ABI nightmare that legacy
clone() is but we can prevent stuff like this happening in the future.)
Well, the first version I nothing to test this with. I don't know how to
reasonably explain what happened but thanks to Adrian I'm now sitting at
home next to a HP Integrity RX2600. I've done some testing and my initial
version had a bug that became obvious when I took a closer look. The switch
stack logic assumes that ar.pfs is stored in r16 and I changed that to r2.
So with that fixed the following test program runs without any problems:
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#include <errno.h>
#include <fcntl.h>
#include <linux/sched.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <syscall.h>
#include <unistd.h>
#define IA64_SYSCALL_OFFSET 1024
#ifndef __NR_clone
#define __NR_clone (104 + IA64_SYSCALL_OFFSET)
#endif
#ifndef __NR_clone2
#define __NR_clone2 (189 + IA64_SYSCALL_OFFSET)
#endif
/*
* sys_clone(unsigned long flags,
* unsigned long stack,
* int *parent_tidptr,
* int *child_tidptr,
* unsigned long tls)
*/
static pid_t ia64_raw_clone(void)
{
return syscall(__NR_clone, SIGCHLD, 0, NULL, NULL, 0);
}
/*
* sys_clone2(unsigned long flags,
* unsigned long stack,
* unsigned long stack_size,
* int *parent_tidptr,
* int *child_tidptr,
* unsigned long tls)
*/
static pid_t ia64_raw_clone2(void)
{
return syscall(__NR_clone2, SIGCHLD, 0, 0, NULL, NULL, 0);
}
/*
* Let's use the "standard stack limit" (i.e. glibc thread size default) for
* stack sizes: 8MB.
*/
#define __STACK_SIZE (8 * 1024 * 1024)
/* This is not always defined in sched.h. */
extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base,
size_t __child_stack_size, int __flags, void *__arg, ...);
pid_t libc_clone2(int (*fn)(void *), void *arg)
{
pid_t ret;
void *stack;
stack = malloc(__STACK_SIZE);
if (!stack)
return -ENOMEM;
return __clone2(fn, stack, __STACK_SIZE, SIGCHLD, arg, NULL, NULL, NULL);
}
static int libc_clone2_child(void *data)
{
fprintf(stderr, "I'll just see myself out\n");
_exit(EXIT_SUCCESS);
}
int main(void)
{
for (int i = 0; i < 1000; i++) {
pid_t pid = ia64_raw_clone();
if (pid < 0)
_exit(EXIT_FAILURE);
if (pid == 0)
_exit(EXIT_SUCCESS);
if (wait(NULL) != pid)
_exit(EXIT_FAILURE);
fprintf(stderr, "ia64_raw_clone() passed\n");
pid = ia64_raw_clone2();
if (pid < 0)
_exit(EXIT_FAILURE);
if (pid == 0)
_exit(EXIT_SUCCESS);
if (wait(NULL) != pid)
_exit(EXIT_FAILURE);
fprintf(stderr, "ia64_raw_clone2() passed\n");
pid = libc_clone2(libc_clone2_child, NULL);
if (pid < 0)
_exit(EXIT_FAILURE);
if (wait(NULL) != pid)
_exit(EXIT_FAILURE);
fprintf(stderr, "libc_clone2() passed\n");
}
_exit(EXIT_SUCCESS);
}
For some more context, please see:
commit
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