Revert "um: Use swap() to make code cleaner"

This reverts commit 9b0da3f22307af693be80f5d3a89dc4c7f360a85.

The sigio.c is clearly user space code which is handled by
arch/um/scripts/Makefile.rules

Revert "um: Use swap() to make code cleaner"

This reverts commit 9b0da3f22307af693be80f5d3a89dc4c7f360a85.

The sigio.c is clearly user space code which is handled by
arch/um/scripts/Makefile.rules (see USER_OBJS rule).

The above mentioned commit simply broke this agreement,
we may not use Linux kernel internal headers in them without
thorough thinking.

Hence, revert the wrong commit.

Link: https://lkml.kernel.org/r/20230724143131.30090-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307212304.cH79zJp1-lkp@intel.com/
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Herve Codina <herve.codina@bootlin.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Richard Weinberger <richard@nod.at>
Cc: Yang Guang <yang.guang5@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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um: Use swap() to make code cleaner

Use the macro 'swap()' defined in 'include/linux/minmax.h' to avoid
opencoding it.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Yang Guang <yang.gu

um: Use swap() to make code cleaner

Use the macro 'swap()' defined in 'include/linux/minmax.h' to avoid
opencoding it.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Yang Guang <yang.guang5@zte.com.cn>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: rename set_signals() to um_set_signals()

Rename set_signals() as there's at least one driver that
uses the same name and can now be built on UM due to PCI
support, and thus we can get symbol con

um: rename set_signals() to um_set_signals()

Rename set_signals() as there's at least one driver that
uses the same name and can now be built on UM due to PCI
support, and thus we can get symbol conflicts.

Also rename set_signals_trace() to be consistent.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: rename set_signals() to um_set_signals()

[ Upstream commit bbe33504d4a7fdab9011211e55e262c869b3f6cc ]

Rename set_signals() as there's at least one driver that
uses the same name and can now be

um: rename set_signals() to um_set_signals()

[ Upstream commit bbe33504d4a7fdab9011211e55e262c869b3f6cc ]

Rename set_signals() as there's at least one driver that
uses the same name and can now be built on UM due to PCI
support, and thus we can get symbol conflicts.

Also rename set_signals_trace() to be consistent.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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um: irq/sigio: Support suspend/resume handling of workaround IRQs

If the sigio workaround needed to be applied to a file descriptor,
set_irq_wake() wouldn't work for it since it would get polled by

um: irq/sigio: Support suspend/resume handling of workaround IRQs

If the sigio workaround needed to be applied to a file descriptor,
set_irq_wake() wouldn't work for it since it would get polled by
the thread instead of causing SIGIO, and thus could never really
cause a wakeup, since the thread notification FD wasn't marked as
being able to wake up the system.

Fix this by marking the thread's notification FD explicitly as a
wake source FD, i.e. not suppressing SIGIO for it in suspend. In
order to not cause spurious wakeups, we then need to remove all
FDs that shouldn't wake up the system from the polling thread. In
order to do this, add unlocked versions of ignore_sigio_fd() and
add_sigio_fd() (nothing else is happening in suspend, so this is
fine), and also modify ignore_sigio_fd() to return -ENOENT if the
FD wasn't originally in there. This doesn't matter because nothing
else currently checks the return value, but the irq code needs to
know which ones to restore the workaround for.

All told, this lets us use a timerfd for the RTC clock in the next
patch, which doesn't send SIGIO.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: Remove IRQ_NONE type

We don't actually use this in um_request_irq(), so it can
never be assigned. It's also not clear what that would be
useful for, so just remove it.

This results in quite a n

um: Remove IRQ_NONE type

We don't actually use this in um_request_irq(), so it can
never be assigned. It's also not clear what that would be
useful for, so just remove it.

This results in quite a number of cleanups, all the way to
removing the "SIGIO on close" startup check, since the data
it assigns (pty_close_sigio) is not used anymore.

While at it, also make this an enum so we get a minimum of
type checking, and remove the IRQ_NONE hack in virtio since
we now no longer have the name twice.

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
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>

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um: sigio: Return error from add_sigio_fd()

If we run out of space, return an error instead of 0.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@n

um: sigio: Return error from add_sigio_fd()

If we run out of space, return an error instead of 0.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: Add SPDX headers for files in arch/um/os-Linux

Convert files to use SPDX header. All files are licensed under the GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard

um: Add SPDX headers for files in arch/um/os-Linux

Convert files to use SPDX header. All files are licensed under the GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: Implement TRACE_IRQFLAGS_SUPPORT

UML enables TRACE_IRQFLAGS_SUPPORT but doesn't actually implement
it. It seems to have been added for lockdep support, but that can't
actually really work well w

um: Implement TRACE_IRQFLAGS_SUPPORT

UML enables TRACE_IRQFLAGS_SUPPORT but doesn't actually implement
it. It seems to have been added for lockdep support, but that can't
actually really work well without IRQ flags tracing, as is also
very noisily reported when enabling CONFIG_DEBUG_LOCKDEP.

Implement it now.

Fixes: 711553efa5b8 ("[PATCH] uml: declare in Kconfig our partial LOCKDEP support")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: Cleanup SIGTERM handling

Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_n

um: Cleanup SIGTERM handling

Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_new_thread_signals().
It disabled the UML exit handler accidently for some processes.
The correct solution is to disable the fatal handler for all
UML helper threads/processes.
Such that last_ditch_exit() does not get called multiple times
and all processes can exit due to SIGTERM.

Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

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um: get rid of pointless include "..." where include <...> will do

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: shared/process.h is empty now; kill it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: -include user.h for USER_OBJ, trim includes

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

UML: make several more things static

- Make some variables and functions static, since they don't need to be
global.

- Remove an unused function - arch/um/kernel/time.c::sched_clock().

- Clean t

UML: make several more things static

- Make some variables and functions static, since they don't need to be
global.

- Remove an unused function - arch/um/kernel/time.c::sched_clock().

- Clean the style a bit as complained by checkpatch.pl.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: random driver fixes

The random driver would essentially hang if the host's /dev/random returned
-EAGAIN. There was a test of need_resched followed by a schedule inside the
loop, but that didn'

uml: random driver fixes

The random driver would essentially hang if the host's /dev/random returned
-EAGAIN. There was a test of need_resched followed by a schedule inside the
loop, but that didn't help and it's the wrong way to work anyway.

The right way is to ask for an interrupt when there is input available from
the host and handle it then rather than polling.

Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup
when there's randomness available again and sleeps. The interrupt routine
just wakes up whatever processes are sleeping on host_read_wait.

There is an atomic_t, host_sleep_count, which counts the number of processes
waiting for randomness. When this reaches zero, the interrupt is disabled.

An added complication is that async I/O notification was only recently added
to /dev/random (by me), so essentially all hosts will lack it. So, we use the
sigio workaround here, which is to have a separate thread poll on the
descriptor and send an interrupt when there is input on it. This mechanism is
activated when a process gets -EAGAIN (activating this multiple times is
harmless, if a bit wasteful) and deactivated by the last process still
waiting.

The module name was changed from "random" to "hw_random" in order for udev to
recognize it.

The sigio workaround needed some changes. sigio_broken was added for cases
when we know that async notification doesn't work. This is now called from
maybe_sigio_broken, which deals with pts devices.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: fix build when SLOB is enabled

Reintroduce uml_kmalloc for the benefit of UML libc code. The
previous tactic of declaring __kmalloc so it could be called directly
from the libc side of the hou

uml: fix build when SLOB is enabled

Reintroduce uml_kmalloc for the benefit of UML libc code. The
previous tactic of declaring __kmalloc so it could be called directly
from the libc side of the house turned out to be getting too intimate
with slab, and it doesn't work with slob.

So, the uml_kmalloc wrapper is back. It calls kmalloc or whatever
that translates into, and libc code calls it.

kfree is left alone since that still works, leaving a somewhat
inconsistent API.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: syle fixes in arch/um/os-Linux

Style fixes in arch/um/os-Linux/irq.c and arch/um/os-Linux/sigio.c:
Updated copyrights
trimmed includes
added severity indicators to printks
CodingStyle fixes

uml: syle fixes in arch/um/os-Linux

Style fixes in arch/um/os-Linux/irq.c and arch/um/os-Linux/sigio.c:
Updated copyrights
trimmed includes
added severity indicators to printks
CodingStyle fixes
turned an bunch of panics into printks
call some libc functions directly instead of going through the
os_* wrappers

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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arch/um: remove duplicate includes

Signed-off-by: Lucas Woods <woodzy@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torva

arch/um: remove duplicate includes

Signed-off-by: Lucas Woods <woodzy@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: const and other tidying

This patch also does some improvements for uml code. Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointe

uml: const and other tidying

This patch also does some improvements for uml code. Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointers etc..

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: Eliminate kernel allocator wrappers

UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic
because the flag constants weren't available in userspace code.
kern_constants.h

uml: Eliminate kernel allocator wrappers

UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic
because the flag constants weren't available in userspace code.
kern_constants.h had made kernel constants available for a long time, so there
is no need for these wrappers any more. Rather, userspace code calls kmalloc
directly with the userspace versions of the gfp flags.

kmalloc isn't a real procedure, so I had to essentially copy the inline
wrapper around __kmalloc.

vmalloc also had its own wrapper for no good reason. This is now gone.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: simplify helper stack handling

run_helper and run_helper_thread had arguments which were the same in all
callers. run_helper's stack_out was always NULL and run_helper_thread's
stack_order was

uml: simplify helper stack handling

run_helper and run_helper_thread had arguments which were the same in all
callers. run_helper's stack_out was always NULL and run_helper_thread's
stack_order was always 0. These are now gone, and the constants folded
into the code.

Also fixed leaks of the helper stack in the AIO and SIGIO code.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: convert libc layer to call read and write

This patch converts calls in the os layer to os_{read,write}_file to calls
directly to libc read() and write() where it is clear that the I/O buffer is

uml: convert libc layer to call read and write

This patch converts calls in the os layer to os_{read,write}_file to calls
directly to libc read() and write() where it is clear that the I/O buffer is
in the kernel.

We can do that here instead of calling os_{read,write}_file_k since we are in
libc code and can call libc directly.

With the change in the calls, error handling needs to be changed to refer to
errno directly rather than the return value of the call.

CATCH_EINTR wrappers were also added where needed.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: tidy libc code

This patch lays some groundwork for the next one, which converts calls to
os_{read,write}_file into {read,write}, by doing some tidying in the affected
areas.

do_not_aio gets re

uml: tidy libc code

This patch lays some groundwork for the next one, which converts calls to
os_{read,write}_file into {read,write}, by doing some tidying in the affected
areas.

do_not_aio gets restructured to make the final result a bit cleaner.

There are also whitespace and other formatting fixes, fixes in error messages,
and a typo fix.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: remove user_util.h

user_util.h isn't needed any more, so delete it and remove all includes of it.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorbl

uml: remove user_util.h

user_util.h isn't needed any more, so delete it and remove all includes of it.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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uml: move SIGIO testing to sigio.c

This patch narrows the sigio interface. The boot-time SIGIO testing used to
be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed
to be g

uml: move SIGIO testing to sigio.c

This patch narrows the sigio interface. The boot-time SIGIO testing used to
be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed
to be global. By moving that code here, those can become static and the
declarations moved from user_util.h.

os_check_bugs is also here because it only does the SIGIO checking. If it
does more, it'll probably move back to start_up.c.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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