linux-stable.git/arch/um/include, branch linux-5.4.y

um: Fix the -Wmissing-prototypes warning for __switch_mm

2024-06-16T11:28:44+00:00

[ Upstream commit 2cbade17b18c0f0fd9963f26c9fc9b057eb1cb3a ]

The __switch_mm function is defined in the user code, and is called
by the kernel code. It should be declared in a shared header.

Fixes: 4dc706c2f292 ("um: take um_mmu.h to asm/mmu.h, clean asm/mmu_context.h a bit")
Signed-off-by: Tiwei Bie 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Fix naming clash between UML and scheduler

2024-02-23T07:25:02+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/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T17:56:34+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

um: use fallback for random_get_entropy() instead of zero

2022-06-22T12:11:15+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

ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP

2022-06-14T16:11:24+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: registers: Rename function names to avoid conflicts and build problems

2022-01-27T08:19:45+00:00

[ Upstream commit 077b7320942b64b0da182aefd83c374462a65535 ]

The function names init_registers() and restore_registers() are used
in several net/ethernet/ and gpu/drm/ drivers for other purposes (not
calls to UML functions), so rename them.

This fixes multiple build errors.

Signed-off-by: Randy Dunlap 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: linux-um@lists.infradead.org
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

Revert "um: Enable CONFIG_CONSTRUCTORS"

2020-02-01T09:34:53+00:00

commit 87c9366e17259040a9118e06b6dc8de986e5d3d1 upstream.

This reverts commit 786b2384bf1c ("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: 786b2384bf1c ("um: Enable CONFIG_CONSTRUCTORS")
Reported-by: Anton Ivanov 
Signed-off-by: Johannes Berg 
Acked-by: Anton Ivanov 
Signed-off-by: Greg Kroah-Hartman 

Signed-off-by: Richard Weinberger

um: Implement copy_thread_tls

2020-01-14T19:08:35+00:00

commit 457677c70c7672a4586b0b8abc396cc1ecdd376d upstream.

This is required for clone3 which passes the TLS value through a
struct rather than a register.

Signed-off-by: Amanieu d'Antras 
Cc: linux-um@lists.infradead.org
Cc:  # 5.3.x
Link: https://lore.kernel.org/r/20200104123928.1048822-1-amanieu@gmail.com
Signed-off-by: Christian Brauner 
Signed-off-by: Greg Kroah-Hartman

mm: treewide: clarify pgtable_page_{ctor,dtor}() naming

2019-09-26T17:10:44+00:00

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland 
Reviewed-by: Mike Rapoport 
Acked-by: Geert Uytterhoeven 	[m68k]
Cc: Anshuman Khandual 
Cc: Matthew Wilcox 
Cc: Michal Hocko 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: consolidate pgtable_cache_init() and pgd_cache_init()

2019-09-24T22:54:09+00:00

Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init().  Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport 
Acked-by: Will Deacon 		[arm64]
Acked-by: Thomas Gleixner 	[x86]
Cc: Catalin Marinas 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds