linux-stable.git/arch/um/include, branch linux-5.17.y

um: line: Use separate IRQs per line

2022-06-14T16:41:39+00:00

[ Upstream commit d5a9597d6916a76663085db984cb8fe97f0a5c56 ]

Today, all possible serial lines (ssl*=) as well as all
possible consoles (con*=) each share a single interrupt
(with a fixed number) with others of the same type.

Now, if you have two lines, say ssl0 and ssl1, and one
of them is connected to an fd you cannot read (e.g. a
file), but the other gets a read interrupt, then both
of them get the interrupt since it's shared. Then, the
read() call will return EOF, since it's a file being
written and there's nothing to read (at least not at
the current offset, at the end).

Unfortunately, this is treated as a read error, and we
close this line, losing all the possible output.

It might be possible to work around this and make the
IRQ sharing work, however, now that we have dynamically
allocated IRQs that are easy to use, simply use that to
achieve separating between the events; then there's no
interrupt for that line and we never attempt the read
in the first place, thus not closing the line.

This manifested itself in the wifi hostap/hwsim tests
where the parallel script communicates via one serial
console and the kernel messages go to another (a file)
and sending data on the communication console caused
the kernel messages to stop flowing into the file.

Reported-by: Jouni Malinen 
Signed-off-by: Johannes Berg 
Acked-By: anton ivanov 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Use asm-generic/dma-mapping.h

2022-06-09T08:26:26+00:00

commit 365719035526e8eda214a1cedb2e1c96e969a0d7 upstream.

If DMA (PCI over virtio) is enabled, then some drivers may
enable CONFIG_DMA_OPS as well, and then we pull in the x86
definition of get_arch_dma_ops(), which uses the dma_ops
symbol, which isn't defined.

Since we don't have real DMA ops nor any kind of IOMMU fix
this in the simplest possible way: pull in the asm-generic
file instead of inheriting the x86 one. It's not clear why
those drivers that do (e.g. VDPA) "select DMA_OPS", and if
they'd even work with this, but chances are nobody will be
wanting to do that anyway, so fixing the build failure is
good enough.

Reported-by: Randy Dunlap 
Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")
Signed-off-by: Johannes Berg 
Tested-by: Randy Dunlap 
Acked-by: Randy Dunlap 
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP

2022-06-09T08:25:16+00:00

commit c200e4bb44e80b343c09841e7caaaca0aac5e5fa upstream.

User mode linux is the last user of the PT_DTRACE flag.  Using the flag to indicate
single stepping is a little confusing and worse changing tsk->ptrace without locking
could potentionally cause problems.

So use a thread info flag with a better name instead of flag in tsk->ptrace.

Remove the definition PT_DTRACE as uml is the last user.

Cc: stable@vger.kernel.org
Acked-by: Johannes Berg 
Tested-by: Kees Cook 
Reviewed-by: Oleg Nesterov 
Link: https://lkml.kernel.org/r/20220505182645.497868-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

um: use fallback for random_get_entropy() instead of zero

2022-05-30T07:27:14+00:00

commit 9f13fb0cd11ed2327abff69f6501a2c124c88b5a upstream.

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.

Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Acked-by: Johannes Berg 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

um: fix and optimize xor select template for CONFIG64 and timetravel mode

2022-04-13T17:27:06+00:00

[ Upstream commit e3a33af812c611d99756e2ec61e9d7068d466bdf ]

Due to dropped inclusion of asm-generic/xor.h, xor_block_8regs symbol is
missing with CONFIG64 and break compilation, as the asm/xor_64.h also did
not include it. The patch recreate the logic from arch/x86, which check
whether AVX is available and add fallbacks for 32bit and 64bit config of
um.

A very minor additional "fix" is, the return of the macro parameter
instead of NULL, as this is the original intent of the macro, but
this does not change the actual behavior.

Fixes: c0ecca6604b8 ("um: enable the use of optimized xor routines in UML")
Signed-off-by: Benjamin Beichler 
Acked-By: Anton Ivanov 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: remove set_fs

2021-12-22T16:56:56+00:00

Remove address space overrides using set_fs() for User Mode Linux.
Note that just like the existing kernel access case of the uaccess
routines the new nofault kernel handlers do not actually have any
exception handling.  This is probably broken, but not change to the
status quo.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Richard Weinberger

um: header debriding - sigio.h

2021-12-21T20:31:36+00:00

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - os.h

2021-12-21T20:31:36+00:00

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - net_*.h

2021-12-21T20:31:35+00:00

externs dead since before the initial merge

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - mem_user.h

2021-12-21T20:31:35+00:00

get_vm(), add_iomem(), phys_offset() dead since 2004;
init_mem_user() and setup_memory() - since before the initial merge.

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger