This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics. The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.
These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:
- trivial duplicated macro definitions have been removed
Note that 'trivial' here means that it's obviously kernel code that
already included all the major kernel headers, and thus gets the new
generic MIN/MAX macros automatically.
- non-trivial duplicated macro definitions are guarded with #ifndef
This is the "yes, they define their own versions, but no, the include
situation is not entirely obvious, and maybe they don't get the
generic version automatically" case.
- strange use case #1
A couple of drivers decided that the way they want to describe their
versioning is with
#define MAJ 1
#define MIN 2
#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)
which adds zero value and I just did my Alexander the Great
impersonation, and rewrote that pointless Gordian knot as
#define DRV_VERSION "1.2"
instead.
- strange use case #2
A couple of drivers thought that it's a good idea to have a random
'MIN' or 'MAX' define for a value or index into a table, rather than
the traditional macro that takes arguments.
These values were re-written as C enum's instead. The new
function-line macros only expand when followed by an open
parenthesis, and thus don't clash with enum use.
Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.
Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Support for preemption
- i386 Rust support
- Huge cleanup by Benjamin Berg
- UBSAN support
- Removal of dead code
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Merge tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux
Pull UML updates from Richard Weinberger:
- Support for preemption
- i386 Rust support
- Huge cleanup by Benjamin Berg
- UBSAN support
- Removal of dead code
* tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits)
um: vector: always reset vp->opened
um: vector: remove vp->lock
um: register power-off handler
um: line: always fill *error_out in setup_one_line()
um: remove pcap driver from documentation
um: Enable preemption in UML
um: refactor TLB update handling
um: simplify and consolidate TLB updates
um: remove force_flush_all from fork_handler
um: Do not flush MM in flush_thread
um: Delay flushing syscalls until the thread is restarted
um: remove copy_context_skas0
um: remove LDT support
um: compress memory related stub syscalls while adding them
um: Rework syscall handling
um: Add generic stub_syscall6 function
um: Create signal stack memory assignment in stub_data
um: Remove stub-data.h include from common-offsets.h
um: time-travel: fix signal blocking race/hang
um: time-travel: remove time_exit()
...
- Core:
- Provide a new mechanism to create interrupt domains. The existing
interfaces have already too many parameters and it's a pain to expand
any of this for new required functionality.
The new function takes a pointer to a data structure as argument. The
data structure combines all existing parameters and allows for easy
extension.
The first extension for this is to handle the instantiation of
generic interrupt chips at the core level and to allow drivers to
provide extra init/exit callbacks.
This is necessary to do the full interrupt chip initialization before
the new domain is published, so that concurrent usage sites won't see
a half initialized interrupt domain. Similar problems exist on
teardown.
This has turned out to be a real problem due to the deferred and
parallel probing which was added in recent years.
Handling this at the core level allows to remove quite some accrued
boilerplate code in existing drivers and avoids horrible workarounds
at the driver level.
- The usual small improvements all over the place
- Drivers
- Add support for LAN966x OIC and RZ/Five SoC
- Split the STM ExtI driver into a microcontroller and a SMP version to
allow building the latter as a module for multi-platform kernels.
- Enable MSI support for Armada 370XP on platforms which do not support
IPIs.
- The usual small fixes and enhancements all over the place.
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Merge tag 'irq-core-2024-07-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull interrupt subsystem updates from Thomas Gleixner:
"Core:
- Provide a new mechanism to create interrupt domains. The existing
interfaces have already too many parameters and it's a pain to
expand any of this for new required functionality.
The new function takes a pointer to a data structure as argument.
The data structure combines all existing parameters and allows for
easy extension.
The first extension for this is to handle the instantiation of
generic interrupt chips at the core level and to allow drivers to
provide extra init/exit callbacks.
This is necessary to do the full interrupt chip initialization
before the new domain is published, so that concurrent usage sites
won't see a half initialized interrupt domain. Similar problems
exist on teardown.
This has turned out to be a real problem due to the deferred and
parallel probing which was added in recent years.
Handling this at the core level allows to remove quite some accrued
boilerplate code in existing drivers and avoids horrible
workarounds at the driver level.
- The usual small improvements all over the place
Drivers:
- Add support for LAN966x OIC and RZ/Five SoC
- Split the STM ExtI driver into a microcontroller and a SMP version
to allow building the latter as a module for multi-platform
kernels
- Enable MSI support for Armada 370XP on platforms which do not
support IPIs
- The usual small fixes and enhancements all over the place"
* tag 'irq-core-2024-07-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
irqdomain: Fix the kernel-doc and plug it into Documentation
genirq: Set IRQF_COND_ONESHOT in request_irq()
irqchip/imx-irqsteer: Handle runtime power management correctly
irqchip/gic-v3: Pass #redistributor-regions to gic_of_setup_kvm_info()
irqchip/bcm2835: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
irqchip/gic-v4: Make sure a VPE is locked when VMAPP is issued
irqchip/gic-v4: Substitute vmovp_lock for a per-VM lock
irqchip/gic-v4: Always configure affinity on VPE activation
Revert "irqchip/dw-apb-ictl: Support building as module"
Revert "Loongarch: Support loongarch avec"
arm64: Kconfig: Allow build irq-stm32mp-exti driver as module
ARM: stm32: Allow build irq-stm32mp-exti driver as module
irqchip/stm32mp-exti: Allow building as module
irqchip/stm32mp-exti: Rename internal symbols
irqchip/stm32-exti: Split MCU and MPU code
arm64: Kconfig: Select STM32MP_EXTI on STM32 platforms
ARM: stm32: Use different EXTI driver on ARMv7m and ARMv7a
irqchip/stm32-exti: Add CONFIG_STM32MP_EXTI
irqchip/dw-apb-ictl: Support building as module
irqchip/riscv-aplic: Simplify the initialization code
...
Several new features here:
- Virtio find vqs API has been reworked
(required to fix the scalability issue we have with
adminq, which I hope to merge later in the cycle)
- vDPA driver for Marvell OCTEON
- virtio fs performance improvement
- mlx5 migration speedups
Fixes, cleanups all over the place.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:
"Several new features here:
- Virtio find vqs API has been reworked (required to fix the
scalability issue we have with adminq, which I hope to merge later
in the cycle)
- vDPA driver for Marvell OCTEON
- virtio fs performance improvement
- mlx5 migration speedups
Fixes, cleanups all over the place"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (56 commits)
virtio: rename virtio_find_vqs_info() to virtio_find_vqs()
virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpers
virtio: convert the rest virtio_find_vqs() users to virtio_find_vqs_info()
virtio_balloon: convert to use virtio_find_vqs_info()
virtiofs: convert to use virtio_find_vqs_info()
scsi: virtio_scsi: convert to use virtio_find_vqs_info()
virtio_net: convert to use virtio_find_vqs_info()
virtio_crypto: convert to use virtio_find_vqs_info()
virtio_console: convert to use virtio_find_vqs_info()
virtio_blk: convert to use virtio_find_vqs_info()
virtio: rename find_vqs_info() op to find_vqs()
virtio: remove the original find_vqs() op
virtio: call virtio_find_vqs_info() from virtio_find_single_vq() directly
virtio: convert find_vqs() op implementations to find_vqs_info()
virtio_pci: convert vp_*find_vqs() ops to find_vqs_info()
virtio: introduce virtio_queue_info struct and find_vqs_info() config op
virtio: make virtio_find_single_vq() call virtio_find_vqs()
virtio: make virtio_find_vqs() call virtio_find_vqs_ctx()
caif_virtio: use virtio_find_single_vq() for single virtqueue finding
vdpa/mlx5: Don't enable non-active VQs in .set_vq_ready()
...
kmsg_dump doesn't forward the panic reason string to the kmsg_dumper
callback.
This patch adds a new struct kmsg_dump_detail, that will hold the
reason and description, and pass it to the dump() callback.
To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc()
function and a macro for backward compatibility.
I've written this for drm_panic, but it can be useful for other
kmsg_dumper.
It allows to see the panic reason, like "sysrq triggered crash"
or "VFS: Unable to mount root fs on xxxx" on the drm panic screen.
v2:
* Use a struct kmsg_dump_detail to hold the reason and description
pointer, for more flexibility if we want to add other parameters.
(Kees Cook)
* Fix powerpc/nvram_64 build, as I didn't update the forward
declaration of oops_to_nvram()
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Kees Cook <kees@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240702122639.248110-1-jfalempe@redhat.com
Since the original virtio_find_vqs() is no longer present, rename
virtio_find_vqs_info() back to virtio_find_vqs().
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Message-Id: <20240708074814.1739223-20-jiri@resnulli.us>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Instead of passing separate names and callbacks arrays
to virtio_find_vqs(), have one of virtual_queue_info structs and
pass it to virtio_find_vqs_info().
Suggested-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Message-Id: <20240708074814.1739223-18-jiri@resnulli.us>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Since the original find_vqs() is no longer present, rename
find_vqs_info() back to find_vqs().
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Message-Id: <20240708074814.1739223-10-jiri@resnulli.us>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Convert existing find_vqs() transport implementations
to use find_vqs_info() config op.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Message-Id: <20240708074814.1739223-7-jiri@resnulli.us>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
UML should not be using the architecture native runtime constants, since
that requires also having the appropriate instruction fixups (and all
the linker script details).
Not that using that code would be impossible, but it's not worth it.
Just point UML at the generic version.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Fixes: e3c92e8171 ("runtime constants: add x86 architecture support")
Link: https://lore.kernel.org/all/20240716143644.GA1827132@thelio-3990X/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most of this is part of my ongoing work to clean up the system call
tables. In this bit, all of the newer architectures are converted to
use the machine readable syscall.tbl format instead in place of complex
macros in include/uapi/asm-generic/unistd.h.
This follows an earlier series that fixed various API mismatches
and in turn is used as the base for planned simplifications.
The other two patches are dead code removal and a warning fix.
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Merge tag 'asm-generic-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
"Most of this is part of my ongoing work to clean up the system call
tables. In this bit, all of the newer architectures are converted to
use the machine readable syscall.tbl format instead in place of
complex macros in include/uapi/asm-generic/unistd.h.
This follows an earlier series that fixed various API mismatches and
in turn is used as the base for planned simplifications.
The other two patches are dead code removal and a warning fix"
* tag 'asm-generic-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
vmlinux.lds.h: catch .bss..L* sections into BSS")
fixmap: Remove unused set_fixmap_offset_io()
riscv: convert to generic syscall table
openrisc: convert to generic syscall table
nios2: convert to generic syscall table
loongarch: convert to generic syscall table
hexagon: use new system call table
csky: convert to generic syscall table
arm64: rework compat syscall macros
arm64: generate 64-bit syscall.tbl
arm64: convert unistd_32.h to syscall.tbl format
arc: convert to generic syscall table
clone3: drop __ARCH_WANT_SYS_CLONE3 macro
kbuild: add syscall table generation to scripts/Makefile.asm-headers
kbuild: verify asm-generic header list
loongarch: avoid generating extra header files
um: don't generate asm/bpf_perf_event.h
csky: drop asm/gpio.h wrapper
syscalls: add generic scripts/syscall.tbl
If we start validating the existence of the asm-generic side of
generated headers, this one causes a warning:
make[3]: *** No rule to make target 'arch/um/include/generated/asm/bpf_perf_event.h', needed by 'all'. Stop.
The problem is that the asm-generic header only exists for the uapi
variant, but arch/um has no uapi headers and instead uses the x86
userspace API.
Add a custom file with an explicit redirect to avoid this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
If open fails, we have already set vp->opened, but it's
not reset so that any further attempts will just return
-ENXIO. Reset vp->opened even if close has nothing to do.
This helps e.g. with slirp4netns handling only a single
connection, you can then restart it and open the device
again.
Link: https://patch.msgid.link/20240703184622.df40c5c38461.Id4e20b48938c6019d99e6133227a34ac059db466@changeid
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Since userspace state is saved in the MM process, kernel using
FPU still doesn't really need to do anything, so this really
is as simple as enabling preemption. The irq critical section
in sigio_handler() needs preempt_disable()/preempt_enable().
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://patch.msgid.link/20240702102549.d2fcea450854.I12f5a53d80ec1e425e66ef272b1e95cb523b608e@changeid
[rebase, remove FPU save/restore, fix x86/um Makefile,
rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Conceptually, we want the memory mappings to always be up to date and
represent whatever is in the TLB. To ensure that, we need to sync them
over in the userspace case and for the kernel we need to process the
mappings.
The kernel will call flush_tlb_* if page table entries that were valid
before become invalid. Unfortunately, this is not the case if entries
are added.
As such, change both flush_tlb_* and set_ptes to track the memory range
that has to be synchronized. For the kernel, we need to execute a
flush_tlb_kern_* immediately but we can wait for the first page fault in
case of set_ptes. For userspace in contrast we only store that a range
of memory needs to be synced and do so whenever we switch to that
process.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-13-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The HVC update was mostly used to compress consecutive calls into one.
This is mostly relevant for userspace where it is already handled by the
syscall stub code.
Simplify the whole logic and consolidate it for both kernel and
userspace. This does remove the sequential syscall compression for the
kernel, however that shouldn't be the main factor in most runs.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-12-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There should be no need for this. It may be that this used to work
around another issue where after a clone the MM was in a bad state.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-11-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There should be no need to flush the memory in flush_thread. Doing this
likely worked around some issue where memory was still incorrectly
mapped when creating or cloning an MM.
With the removal of the special clone path, that isn't relevant anymore.
However, add the flush into MM initialization so that any new userspace
MM is guaranteed to be clean.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-10-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
As running the syscalls is expensive due to context switches, we should
do so as late as possible in case more syscalls need to be queued later
on. This will also benefit a later move to a SECCOMP enabled userspace
as in that case the need for extra context switches is removed entirely.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-9-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The kernel flushes the memory ranges anyway for CoW and does not assume
that the userspace process has anything set up already. So, start with a
fresh process for the new mm context.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-8-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The current LDT code has a few issues that mean it should be redone in a
different way once we always start with a fresh MM even when cloning.
In a new and better world, the kernel would just ensure its own LDT is
clear at startup. At that point, all that is needed is a simple function
to populate the LDT from another MM in arch_dup_mmap combined with some
tracking of the installed LDT entries for each MM.
Note that the old implementation was even incorrect with regard to
reading, as it copied out the LDT entries in the internal format rather
than converting them to the userspace structure.
Removal should be fine as the LDT is not used for thread-local storage
anymore.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-7-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
To keep the number of syscalls that the stub has to do lower, compress
two consecutive syscalls of the same type if the second is just a
continuation of the first.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-6-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Rework syscall handling to be platform independent. Also create a clean
split between queueing of syscalls and flushing them out, removing the
need to keep state in the code that triggers the syscalls.
The code adds syscall_data_len to the global mm_id structure. This will
be used later to allow surrounding code to track whether syscalls still
need to run and if errors occurred.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-5-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When we switch to use seccomp, we need both the signal stack and other
data (i.e. syscall information) to co-exist in the stub data. To
facilitate this, start by defining separate memory areas for the stack
and syscall data.
This moves the signal stack onto a new page as the memory area is not
sufficient to hold both signal stack and syscall information.
Only change the signal stack setup for now, as the syscall code will be
reworked later.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Further commits will require values from common-offsets.h inside
stub-data.h. Resolve the possible circular dependency and simply use
offsetof() inside stub_32.h and stub_64.h.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-2-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When signals are hard-blocked in order to do time-travel
socket processing, we set signals_blocked and then handle
SIGIO signals by setting the SIGIO bit in signals_pending.
When unblocking, we first set signals_blocked to 0, and
then handle all pending signals. We have to set it first,
so that we can again properly block/unblock inside the
unblock, if the time-travel handlers need to be processed.
Unfortunately, this is racy. We can get into this situation:
// signals_pending = SIGIO_MASK
unblock_signals_hard()
signals_blocked = 0;
if (signals_pending && signals_enabled) {
block_signals();
unblock_signals()
...
sig_handler_common(SIGIO, NULL, NULL);
sigio_handler()
...
sigio_reg_handler()
irq_do_timetravel_handler()
reg->timetravel_handler() ==
vu_req_interrupt_comm_handler()
vu_req_read_message()
vhost_user_recv_req()
vhost_user_recv()
vhost_user_recv_header()
// reads 12 bytes header of
// 20 bytes message
<-- receive SIGIO here <--
sig_handler()
int enabled = signals_enabled; // 1
if ((signals_blocked || !enabled) && (sig == SIGIO)) {
if (!signals_blocked && time_travel_mode == TT_MODE_EXTERNAL)
sigio_run_timetravel_handlers()
_sigio_handler()
sigio_reg_handler()
... as above ...
vhost_user_recv_header()
// reads 8 bytes that were message payload
// as if it were header - but aborts since
// it then gets -EAGAIN
...
--> end signal handler -->
// continue in vhost_user_recv()
// full_read() for 8 bytes payload busy loops
// entire process hangs here
Conceptually, to fix this, we need to ensure that the
signal handler cannot run while we hard-unblock signals.
The thing that makes this more complex is that we can be
doing hard-block/unblock while unblocking. Introduce a
new signals_blocked_pending variable that we can keep at
non-zero as long as pending signals are being processed,
then we only need to ensure it's decremented safely and
the signal handler will only increment it if it's already
non-zero (or signals_blocked is set, of course.)
Note also that only the outermost call to hard-unblock is
allowed to decrement signals_blocked_pending, since it
could otherwise reach zero in an inner call, and leave
the same race happening if the timetravel_handler loops,
but that's basically required of it.
Fixes: d6b399a0e0 ("um: time-travel/signals: fix ndelay() in interrupt")
Link: https://patch.msgid.link/20240703110144.28034-2-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
With ARCH=um, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/um/drivers/harddog.o
Add the missing invocation of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://patch.msgid.link/20240702-md-um-arch-um-drivers-v1-1-79e4f50b5bab@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
With external time travel, a LOT of message can end up
being exchanged on the socket, taking a significant
amount of time just to do that.
Add a new shared memory optimisation to that, where a
number of changes are made:
- the controller sends a client ID and a shared memory FD
(and a logging FD we don't use) in the ACK message to
the initial START
- the shared memory holds the current time and the
free_until value, so that there's no need to exchange
messages for that
- if the client that's running has shared memory support,
any client (the running one included) can request the
next time it wants to run inside the shared memory,
rather than sending a message, by also updating the
free_until value
- when shared memory is enabled, RUN/WAIT messages no
longer have an ACK, further cutting down on messages
Together, this can reduce the number of messages very
significantly, and reduce overall test/simulation run time.
Co-developed-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Link: https://patch.msgid.link/20240702192118.6ad0a083f574.Ie41206c8ce4507fe26b991937f47e86c24ca7a31@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add a message type to the time-travel protocol to broadcast
a small (64-bit) value to all participants in a simulation.
The main use case is to have an identical message come to
all participants in a simulation, e.g. to separate out logs
for different tests running in a single simulation.
Down in the guts of time_travel_handle_message() we can't
use printk() and not even printk_deferred(), so just store
the message and print it at the start of the userspace()
function.
Unfortunately this means that other prints in the kernel
can actually bypass the message, but in most cases where
this is used, for example to separate test logs, userspace
will be involved. Also, even if we could use
printk_deferred(), we'd still need to flush it out in the
userspace() function since otherwise userspace messages
might cross it.
As a result, this is a reasonable compromise, there's no
need to have any core changes and it solves the main use
case we have for it.
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Link: https://patch.msgid.link/20240702192118.c4093bc5b15e.I2ca8d006b67feeb866ac2017af7b741c9e06445a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Current calculation of max_low_pfn is introduced in commit af84eab208
("[PATCH] uml: fix LVM crash"). It is intended to set max_low_pfn to the
same value as max_pfn.
But I am not sure why the max_pfn is set to totalram_pages, which
represents the number of usable pages in system instead of an absolute
page frame number. (The change history stops there.)
While we have already calculate it in setup_physmem(), so not necessary
to do it again.
Also this would help changing totalram_pages accounting, since we plan
to move the accounting into __free_pages_core(). With this change,
totalram_pages may not represent the total usable pages at this point,
since some pages would be deferred initialized.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Alasdair G Kergon <agk@redhat.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Mike Rapoport (IBM) <rppt@kernel.org>
CC: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://patch.msgid.link/20240615034150.2958-1-richard.weiyang@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
At present, Rust in the kernel only supports 64-bit x86, so UML has
followed suit. However, it's significantly easier to support 32-bit i386
on UML than on bare metal, as UML does not use the -mregparm option
(which alters the ABI), which is not yet supported by rustc[1].
Add support for CONFIG_RUST on um/i386, by adding a new target config to
generate_rust_target, and replacing various checks on CONFIG_X86_64 to
also support CONFIG_X86_32.
We still use generate_rust_target, rather than a built-in rustc target,
in order to match x86_64, provide a future place for -mregparm, and more
easily disable floating point instructions.
With these changes, the KUnit tests pass with:
kunit.py run --make_options LLVM=1 --kconfig_add CONFIG_RUST=y
--kconfig_add CONFIG_64BIT=n --kconfig_add CONFIG_FORTIFY_SOURCE=n
An earlier version of these changes was proposed on the Rust-for-Linux
github[2].
[1]: https://github.com/rust-lang/rust/issues/116972
[2]: https://github.com/Rust-for-Linux/linux/pull/966
Signed-off-by: David Gow <davidgow@google.com>
Link: https://patch.msgid.link/20240604224052.3138504-1-davidgow@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently /proc/sysemu will never be registered, as sysemu_supported
is initialized to zero implicitly and no code updates it. And there is
also nothing to configure via sysemu in UML anymore.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20240527134024.1539848-3-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Commit fb5d1d389c ("ubd: open the backing files in ubd_add")
removed the last use of ubd_mutex.
Remove it.
Build and kernel startup test only.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20240505001508.255096-1-linux@treblig.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at
compile time. UML supports these via its UML_IOMEM_EMULATION so let that
select HAS_IOPORT and also reflect this in NO_IOPORT_MAP.
Co-developed-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://patch.msgid.link/20240403124300.65379-2-schnelle@linux.ibm.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Remove the pcap driver in UML. It is obsolete. It does not build on
recent systems due to changes in libpcap and its dependencies.
The vector driver's raw transport in UML provides identical
functionality.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://patch.msgid.link/20240328132424.376456-1-anton.ivanov@cambridgegreys.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When in time-travel mode (infinite-cpu or external) time should not pass
for writing to the console. As such, it makes sense to put the FD for
the output side into blocking mode and simply let any write to it hang.
If we did not do this, then time could pass waiting for the console to
become writable again. This is not desirable as it has random effects on
the clock between runs.
Implement this by duplicating the FD if output is active in a relevant
mode and setting the duplicate to be blocking. This avoids changing the
input channel to be blocking should it exists. After this, use the
blocking FD for all write operations and do not allocate an IRQ it is
set.
Without time-travel mode fd_out will always match fd_in and IRQs are
registered.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-4-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In the next commit, we are going to set the output FD to be blocking.
Once that is done, the write() may be short if an interrupt happens
while it is writing out data. As such, to properly catch an EINTR error,
we need to retry the write.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If the read/write function returns an error then we expect to see an
event/IRQ later on. However, this will only happen after an EAGAIN as we
are using edge based event triggering.
As such, EINTR needs to be caught should it happen.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-2-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When in time-travel mode, the eventfd events are read even when signals
are blocked as SIGIO still needs to be processed. In this case, the
event is cleared on the eventfd but the IRQ still needs to be fired
later.
We did already ensure that the SIGIO handler is run again. However, the
FDs are configured to be level triggered, so that eventfd will not
notify again. As such, add some logic to mark the IRQ as pending and
process it at the next opportunity.
To avoid duplication, reuse the logic used for the suspend/resume case.
This does not really change anything except for delaying running the
IRQs with timetravel_handler at a slightly later point in time (and
possibly running non-timetravel IRQs that shouldn't happen earlier).
While at it, move marking as pending into irq_event_handler as that is
the more logical place for it to happen.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Move the nonrot flag into the queue_limits feature field so that it can
be set atomically with the queue frozen.
Use the chance to switch to defaulting to non-rotational and require
the driver to opt into rotational, which matches the polarity of the
sysfs interface.
For the z2ram, ps3vram, 2x memstick, ubiblock and dcssblk the new
rotational flag is not set as they clearly are not rotational despite
this being a behavior change. There are some other drivers that
unconditionally set the rotational flag to keep the existing behavior
as they arguably can be used on rotational devices even if that is
probably not their main use today (e.g. virtio_blk and drbd).
The flag is automatically inherited in blk_stack_limits matching the
existing behavior in dm and md.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
