Two independent changes here ended up going into the tree
one after another, without a necessary rename, fix that.
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Fixes: f185063bff ("um: Move timer-internal.h to non-shared")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
In external or inf-cpu time-travel mode, ndelay/udelay currently
just waste CPU time since the simulation time doesn't advance.
Implement them properly in this case.
Note that the "if (time_travel_mode == ...)" parts compile out
if CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, time_travel_mode is
defined to TT_MODE_OFF in that case.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This implements synchronized time-travel mode which - using a special
application on a unix socket - lets multiple machines take part in a
time-travelling simulation together.
The protocol for the unix domain socket is defined in the new file
include/uapi/linux/um_timetravel.h.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Instead of tracking all the various timer configurations,
modify the time-travel mode to have an event scheduler and
use a timer event on the scheduler to handle the different
timer configurations.
This doesn't change the function right now, but it prepares
the code for having different kinds of events in the future
(i.e. interrupts coming from other devices that are part of
co-simulation.)
While at it, also move time_travel_sleep() to time.c to
reduce the externally visible API surface.
Also, we really should mark time-travel as incompatible with
SMP, even if UML doesn't support SMP yet.
Finally, I noticed a bug while developing this - if we move
time forward due to consuming time while reading the clock,
we might move across the next event and that would cause us
to go backward in time when we then handle that event. Fix
that by invoking the whole event machine in this case, but
in order to simplify this, make reading the clock only cost
something when interrupts are not disabled. Otherwise, we'd
have to hook into the interrupt delivery machinery etc. and
that's somewhat intrusive.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This file isn't really shared, it's only used on the kernel side,
not on the user side. Remove the include from the user-side and
move the file to a better place.
While at it, rename it to time-internal.h, it's not really just
timers but all kinds of things related to timekeeping.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull x86 MPX removal from Dave Hansen:
"MPX requires recompiling applications, which requires compiler
support. Unfortunately, GCC 9.1 is expected to be be released without
support for MPX. This means that there was only a relatively small
window where folks could have ever used MPX. It failed to gain wide
adoption in the industry, and Linux was the only mainstream OS to ever
support it widely.
Support for the feature may also disappear on future processors.
This set completes the process that we started during the 5.4 merge
window when the MPX prctl()s were removed. XSAVE support is left in
place, which allows MPX-using KVM guests to continue to function"
* tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx:
x86/mpx: remove MPX from arch/x86
mm: remove arch_bprm_mm_init() hook
x86/mpx: remove bounds exception code
x86/mpx: remove build infrastructure
x86/alternatives: add missing insn.h include
Pull y2038 updates from Arnd Bergmann:
"Core, driver and file system changes
These are updates to device drivers and file systems that for some
reason or another were not included in the kernel in the previous
y2038 series.
I've gone through all users of time_t again to make sure the kernel is
in a long-term maintainable state, replacing all remaining references
to time_t with safe alternatives.
Some related parts of the series were picked up into the nfsd, xfs,
alsa and v4l2 trees. A final set of patches in linux-mm removes the
now unused time_t/timeval/timespec types and helper functions after
all five branches are merged for linux-5.6, ensuring that no new users
get merged.
As a result, linux-5.6, or my backport of the patches to 5.4 [1],
should be the first release that can serve as a base for a 32-bit
system designed to run beyond year 2038, with a few remaining caveats:
- All user space must be compiled with a 64-bit time_t, which will be
supported in the coming musl-1.2 and glibc-2.32 releases, along
with installed kernel headers from linux-5.6 or higher.
- Applications that use the system call interfaces directly need to
be ported to use the time64 syscalls added in linux-5.1 in place of
the existing system calls. This impacts most users of futex() and
seccomp() as well as programming languages that have their own
runtime environment not based on libc.
- Applications that use a private copy of kernel uapi header files or
their contents may need to update to the linux-5.6 version, in
particular for sound/asound.h, xfs/xfs_fs.h, linux/input.h,
linux/elfcore.h, linux/sockios.h, linux/timex.h and
linux/can/bcm.h.
- A few remaining interfaces cannot be changed to pass a 64-bit
time_t in a compatible way, so they must be configured to use
CLOCK_MONOTONIC times or (with a y2106 problem) unsigned 32-bit
timestamps. Most importantly this impacts all users of 'struct
input_event'.
- All y2038 problems that are present on 64-bit machines also apply
to 32-bit machines. In particular this affects file systems with
on-disk timestamps using signed 32-bit seconds: ext4 with
ext3-style small inodes, ext2, xfs (to be fixed soon) and ufs"
[1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y2038-endgame
* tag 'y2038-drivers-for-v5.6-signed' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (21 commits)
Revert "drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC"
y2038: sh: remove timeval/timespec usage from headers
y2038: sparc: remove use of struct timex
y2038: rename itimerval to __kernel_old_itimerval
y2038: remove obsolete jiffies conversion functions
nfs: fscache: use timespec64 in inode auxdata
nfs: fix timstamp debug prints
nfs: use time64_t internally
sunrpc: convert to time64_t for expiry
drm/etnaviv: avoid deprecated timespec
drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC
drm/msm: avoid using 'timespec'
hfs/hfsplus: use 64-bit inode timestamps
hostfs: pass 64-bit timestamps to/from user space
packet: clarify timestamp overflow
tsacct: add 64-bit btime field
acct: stop using get_seconds()
um: ubd: use 64-bit time_t where possible
xtensa: ISS: avoid struct timeval
dlm: use SO_SNDTIMEO_NEW instead of SO_SNDTIMEO_OLD
...
Pull UML updates from Anton Ivanov:
"I am sending this on behalf of Richard who is traveling.
This contains the following changes for UML:
- Fix for time travel mode
- Disable CONFIG_CONSTRUCTORS again
- A new command line option to have an non-raw serial line
- Preparations to remove obsolete UML network drivers"
* tag 'for-linus-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Fix time-travel=inf-cpu with xor/raid6
Revert "um: Enable CONFIG_CONSTRUCTORS"
um: Mark non-vector net transports as obsolete
um: Add an option to make serial driver non-raw
Today, I erroneously built a time-travel configuration with btrfs
enabled, and noticed it cannot boot in time-travel=inf-cpu mode,
both xor and raid6 speed measurement gets stuck.
For xor, work around it by picking the first algorithm if inf-cpu
mode is enabled.
For raid6, I didn't find such a workaround, so disallow enabling
time-travel mode if RAID6_PQ_BENCHMARK is enabled.
With this, and RAID6_PQ_BENCHMARK disabled, I can boot a kernel
that has btrfs enabled in time-travel=inf-cpu mode.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This reverts commit 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS").
There are two issues with this commit, uncovered by Anton in tests
on some (Debian) systems:
1) I completely forgot to call any constructors if CONFIG_CONSTRUCTORS
isn't set. Don't recall now if it just wasn't needed on my system, or
if I never tested this case.
2) With that fixed, it works - with CONFIG_CONSTRUCTORS *unset*. If I
set CONFIG_CONSTRUCTORS, it fails again, which isn't totally
unexpected since whatever wanted to run is likely to have to run
before the kernel init etc. that calls the constructors in this case.
Basically, some constructors that gcc emits (libc has?) need to run
very early during init; the failure mode otherwise was that the ptrace
fork test already failed:
----------------------
$ ./linux mem=512M
Core dump limits :
soft - 0
hard - NONE
Checking that ptrace can change system call numbers...check_ptrace : child exited with exitcode 6, while expecting 0; status 0x67f
Aborted
----------------------
Thinking more about this, it's clear that we simply cannot support
CONFIG_CONSTRUCTORS in UML. All the cases we need now (gcov, kasan)
involve not use of the __attribute__((constructor)), but instead
some constructor code/entry generated by gcc. Therefore, we cannot
distinguish between kernel constructors and system constructors.
Thus, revert this commit.
Cc: stable@vger.kernel.org [5.4+]
Fixes: 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS")
Reported-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
The ubd code suffers from a possible y2038 overflow on 32-bit
architectures, both for the cow header and the os_file_modtime()
function.
Replace time_t with time64_t to extend the ubd_kern side as much
as possible.
Whether this makes a difference for the user side depends on
the host libc implementation that may use either 32-bit or 64-bit
time_t.
For the cow file format, the header contains an unsigned 32-bit
timestamp, which is good until y2106, passing this through a
'long long' gives us a consistent interpretation between 32-bit
and 64-bit um kernels.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
In the x86 MM code we'd like to untangle various types of historic
header dependency spaghetti, but for this we'd need to pass to
the generic vmalloc code various vmalloc related defines that
customarily come via the <asm/page.h> low level arch header.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
