linux-stable.git/arch/um, branch v6.1.78

um: time-travel: fix time corruption

2024-02-05T20:12:57+00:00

[ Upstream commit abe4eaa8618bb36c2b33e9cdde0499296a23448c ]

In 'basic' time-travel mode (without =inf-cpu or =ext), we
still get timer interrupts. These can happen at arbitrary
points in time, i.e. while in timer_read(), which pushes
time forward just a little bit. Then, if we happen to get
the interrupt after calculating the new time to push to,
but before actually finishing that, the interrupt will set
the time to a value that's incompatible with the forward,
and we'll crash because time goes backwards when we do the
forwarding.

Fix this by reading the time_travel_time, calculating the
adjustment, and doing the adjustment all with interrupts
disabled.

Reported-by: Vincent Whitchurch 
Signed-off-by: Johannes Berg 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: net: Fix return type of uml_net_start_xmit()

2024-02-05T20:12:57+00:00

[ Upstream commit 7d748f60a4b82b50bf25fad1bd42d33f049f76aa ]

With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
warning in clang aims to catch these at compile time, which reveals:

  arch/um/drivers/net_kern.c:353:21: warning: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Wincompatible-function-pointer-types-strict]
    353 |         .ndo_start_xmit         = uml_net_start_xmit,
        |                                   ^~~~~~~~~~~~~~~~~~
  1 warning generated.

->ndo_start_xmit() in 'struct net_device_ops' expects a return type of
'netdev_tx_t', not 'int'. Adjust the return type of uml_net_start_xmit()
to match the prototype's to resolve the warning. While UML does not
currently implement support for kCFI, it could in the future, which
means this warning becomes a fatal CFI failure at run time.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202310031340.v1vPh207-lkp@intel.com/
Acked-by: Anton Ivanov 
Signed-off-by: Nathan Chancellor 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Don't use vfprintf() for os_info()

2024-02-05T20:12:57+00:00

[ Upstream commit 236f9fe39b02c15fa5530b53e9cca48354394389 ]

The threads allocated inside the kernel have only a single page of
stack. Unfortunately, the vfprintf function in standard glibc may use
too much stack-space, overflowing it.

To make os_info safe to be used by helper threads, use the kernel
vscnprintf function into a smallish buffer and write out the information
to stderr.

Signed-off-by: Benjamin Berg 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Fix naming clash between UML and scheduler

2024-02-05T20:12:57+00:00

[ Upstream commit 541d4e4d435c8b9bfd29f70a1da4a2db97794e0a ]

__cant_sleep was already used and exported by the scheduler.
The name had to be changed to a UML specific one.

Signed-off-by: Anton Ivanov 
Reviewed-by: Peter Lafreniere 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Fix hostaudio build errors

2023-09-13T07:42:58+00:00

[ Upstream commit db4bfcba7bb8d10f00bba2a3da6b9a9c2a1d7b71 ]

Use "select" to ensure that the required kconfig symbols are set
as expected.
Drop HOSTAUDIO since it is now equivalent to UML_SOUND.

Set CONFIG_SOUND=m in ARCH=um defconfig files to maintain the
status quo of the default configs.

Allow SOUND with UML regardless of HAS_IOMEM. Otherwise there is a
kconfig warning for unmet dependencies. (This was not an issue when
SOUND was defined in arch/um/drivers/Kconfig. I have done 50 randconfig
builds and didn't find any issues.)

This fixes build errors when CONFIG_SOUND is not set:

ld: arch/um/drivers/hostaudio_kern.o: in function `hostaudio_cleanup_module':
hostaudio_kern.c:(.exit.text+0xa): undefined reference to `unregister_sound_mixer'
ld: hostaudio_kern.c:(.exit.text+0x15): undefined reference to `unregister_sound_dsp'
ld: arch/um/drivers/hostaudio_kern.o: in function `hostaudio_init_module':
hostaudio_kern.c:(.init.text+0x19): undefined reference to `register_sound_dsp'
ld: hostaudio_kern.c:(.init.text+0x31): undefined reference to `register_sound_mixer'
ld: hostaudio_kern.c:(.init.text+0x49): undefined reference to `unregister_sound_dsp'

and this kconfig warning:
WARNING: unmet direct dependencies detected for SOUND

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: d886e87cb82b ("sound: make OSS sound core optional")
Signed-off-by: Randy Dunlap 
Reported-by: kernel test robot 
Closes: lore.kernel.org/r/202307141416.vxuRVpFv-lkp@intel.com
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: Johannes Berg 
Cc: linux-um@lists.infradead.org
Cc: Tejun Heo 
Cc: Takashi Iwai 
Cc: Jaroslav Kysela 
Cc: Masahiro Yamada 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Nicolas Schier 
Cc: linux-kbuild@vger.kernel.org
Cc: alsa-devel@alsa-project.org
Reviewed-by: Masahiro Yamada 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T18:03:47+00:00

commit 9349b5cd0908f8afe95529fc7a8cbb1417df9b0c upstream

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner 
Acked-by: Richard Weinberger 
Link: https://lore.kernel.org/r/20230613224545.493148694@linutronix.de
Signed-off-by: Daniel Sneddon 
Signed-off-by: Greg Kroah-Hartman

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

2023-08-03T08:24:15+00:00

commit dddfa05eb58076ad60f9a66e7155a5b3502b2dd5 upstream.

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 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202307212304.cH79zJp1-lkp@intel.com/
Cc: Anton Ivanov 
Cc: Herve Codina 
Cc: Jason A. Donenfeld 
Cc: Johannes Berg 
Cc: Rasmus Villemoes 
Cc: Richard Weinberger 
Cc: Yang Guang 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

um: Use HOST_DIR for mrproper

2023-07-19T14:22:10+00:00

commit a5a319ec2c2236bb96d147c16196d2f1f3799301 upstream.

When HEADER_ARCH was introduced, the MRPROPER_FILES (then MRPROPER_DIRS)
list wasn't adjusted, leaving SUBARCH as part of the path argument.
This resulted in the "mrproper" target not cleaning up arch/x86/... when
SUBARCH was specified. Since HOST_DIR is arch/$(HEADER_ARCH), use it
instead to get the correct path.

Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: Johannes Berg 
Cc: Azeem Shaikh 
Cc: linux-um@lists.infradead.org
Fixes: 7bbe7204e937 ("um: merge Makefile-{i386,x86_64}")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20230606222442.never.807-kees@kernel.org
Signed-off-by: Greg Kroah-Hartman

mm: always expand the stack with the mmap write lock held

2023-07-01T11:16:25+00:00

commit 8d7071af890768438c14db6172cc8f9f4d04e184 upstream

This finishes the job of always holding the mmap write lock when
extending the user stack vma, and removes the 'write_locked' argument
from the vm helper functions again.

For some cases, we just avoid expanding the stack at all: drivers and
page pinning really shouldn't be extending any stacks.  Let's see if any
strange users really wanted that.

It's worth noting that architectures that weren't converted to the new
lock_mm_and_find_vma() helper function are left using the legacy
"expand_stack()" function, but it has been changed to drop the mmap_lock
and take it for writing while expanding the vma.  This makes it fairly
straightforward to convert the remaining architectures.

As a result of dropping and re-taking the lock, the calling conventions
for this function have also changed, since the old vma may no longer be
valid.  So it will now return the new vma if successful, and NULL - and
the lock dropped - if the area could not be extended.

Signed-off-by: Linus Torvalds 
[6.1: Patch drivers/iommu/io-pgfault.c instead]
Signed-off-by: Samuel Mendoza-Jonas 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

um: harddog: fix modular build

2023-06-09T08:34:10+00:00

[ Upstream commit 73a23d7710331a530e972903318528b75e5a5f58 ]

Since we no longer (want to) export any libc symbols the
_user portions of any drivers need to be built into image
rather than the module. I missed this for the watchdog.
Fix the watchdog accordingly.

Reported-by: kernel test robot 
Signed-off-by: Johannes Berg 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin