linux-stable.git/arch/um/kernel, branch linux-6.14.y Linux kernel stable tree um: Update min_low_pfn to match changes in uml_reserved 2025-05-29T09:12:37+00:00 Tiwei Bie tiwei.btw@antgroup.com 2025-02-21T04:18:55+00:00 380f10ee5752ba93f4ace3b86a3b26f8abb1b0c7 [ Upstream commit e82cf3051e6193f61e03898f8dba035199064d36 ] When uml_reserved is updated, min_low_pfn must also be updated accordingly. Otherwise, min_low_pfn will not accurately reflect the lowest available PFN. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20250221041855.1156109-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e82cf3051e6193f61e03898f8dba035199064d36 ]

When uml_reserved is updated, min_low_pfn must also be updated
accordingly. Otherwise, min_low_pfn will not accurately reflect
the lowest available PFN.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20250221041855.1156109-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: work around sched_yield not yielding in time-travel mode 2025-05-02T06:02:02+00:00 Benjamin Berg benjamin.berg@intel.com 2025-03-14T13:08:15+00:00 990ddc65173776f1e01e7135d8c1fd5f8fd4d5d2 [ Upstream commit 887c5c12e80c8424bd471122d2e8b6b462e12874 ] sched_yield by a userspace may not actually cause scheduling in time-travel mode as no time has passed. In the case seen it appears to be a badly implemented userspace spinlock in ASAN. Unfortunately, with time-travel it causes an extreme slowdown or even deadlock depending on the kernel configuration (CONFIG_UML_MAX_USERSPACE_ITERATIONS). Work around it by accounting time to the process whenever it executes a sched_yield syscall. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20250314130815.226872-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 887c5c12e80c8424bd471122d2e8b6b462e12874 ]

sched_yield by a userspace may not actually cause scheduling in
time-travel mode as no time has passed. In the case seen it appears to
be a badly implemented userspace spinlock in ASAN. Unfortunately, with
time-travel it causes an extreme slowdown or even deadlock depending on
the kernel configuration (CONFIG_UML_MAX_USERSPACE_ITERATIONS).

Work around it by accounting time to the process whenever it executes a
sched_yield syscall.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20250314130815.226872-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: remove copy_from_kernel_nofault_allowed 2025-04-10T12:44:33+00:00 Benjamin Berg benjamin.berg@intel.com 2025-02-10T16:09:26+00:00 bb758c41bda94cbe73f36aea06f98ad8202e3bd2 [ Upstream commit 84a6fc378471fbeaf48f8604566a5a33a3d63c18 ] There is no need to override the default version of this function anymore as UML now has proper _nofault memory access functions. Doing this also fixes the fact that the implementation was incorrect as using mincore() will incorrectly flag pages as inaccessible if they were swapped out by the host. Fixes: f75b1b1bedfb ("um: Implement probe_kernel_read()") Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20250210160926.420133-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 84a6fc378471fbeaf48f8604566a5a33a3d63c18 ]

There is no need to override the default version of this function
anymore as UML now has proper _nofault memory access functions.

Doing this also fixes the fact that the implementation was incorrect as
using mincore() will incorrectly flag pages as inaccessible if they were
swapped out by the host.

Fixes: f75b1b1bedfb ("um: Implement probe_kernel_read()")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20250210160926.420133-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: convert irq_lock to raw spinlock 2025-02-12T22:40:59+00:00 Johannes Berg johannes.berg@intel.com 2025-01-10T12:54:06+00:00 96178631c3f53398044ed437010f7632ad764bf8 Since this is deep in the architecture, and the code is called nested into other deep management code, this really needs to be a raw spinlock. Convert it. Link: https://patch.msgid.link/20250110125550.32479-8-johannes@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
Since this is deep in the architecture, and the code is
called nested into other deep management code, this really
needs to be a raw spinlock. Convert it.

Link: https://patch.msgid.link/20250110125550.32479-8-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: avoid copying FP state from init_task 2025-02-12T22:40:38+00:00 Benjamin Berg benjamin.berg@intel.com 2024-12-17T20:27:44+00:00 8891b176d350ec5ea9a39c6ef4c99bd63d68e64c The init_task instance of struct task_struct is statically allocated and does not contain the dynamic area for the userspace FP registers. As such, limit the copy to the valid area of init_task and fill the rest with zero. Note that the FP state is only needed for userspace, and as such it is entirely reasonable for init_task to not contain it. Reported-by: Brian Norris <briannorris@chromium.org> Closes: https://lore.kernel.org/Z1ySXmjZm-xOqk90@google.com Fixes: 3f17fed21491 ("um: switch to regset API and depend on XSTATE") Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241217202745.1402932-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
The init_task instance of struct task_struct is statically allocated and
does not contain the dynamic area for the userspace FP registers. As
such, limit the copy to the valid area of init_task and fill the rest
with zero.

Note that the FP state is only needed for userspace, and as such it is
entirely reasonable for init_task to not contain it.

Reported-by: Brian Norris <briannorris@chromium.org>
Closes: https://lore.kernel.org/Z1ySXmjZm-xOqk90@google.com
Fixes: 3f17fed21491 ("um: switch to regset API and depend on XSTATE")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241217202745.1402932-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Merge tag 'uml-for-linus-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux 2025-01-31T02:29:40+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-01-31T02:29:40+00:00 69e858e0b8b2ea07759e995aa383e8780d9d140c Pull UML updates from Richard Weinberger: - hostfs: Convert to writepages - many cleanups: removal of dead macros, missing __init * tag 'uml-for-linus-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: um: Remove unused asm/archparam.h header um: Include missing headers in asm/pgtable.h hostfs: Convert to writepages um: rtc: use RTC time when calculating the alarm um: Remove unused user_context function um: Remove unused THREAD_NAME_LEN macro um: Remove unused PGD_BOUND macro um: Mark setup_env_path as __init um: Mark install_fatal_handler as __init um: Mark set_stklim as __init um: Mark get_top_address as __init um: Mark parse_cache_line as __init um: Mark parse_host_cpu_flags as __init um: Count iomem_size only once in physmem calculation um: Remove obsolete fixmap support um: Remove unused MODULES_LEN macro 
Pull UML updates from Richard Weinberger:

 - hostfs: Convert to writepages

 - many cleanups: removal of dead macros, missing __init

* tag 'uml-for-linus-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux:
  um: Remove unused asm/archparam.h header
  um: Include missing headers in asm/pgtable.h
  hostfs: Convert to writepages
  um: rtc: use RTC time when calculating the alarm
  um: Remove unused user_context function
  um: Remove unused THREAD_NAME_LEN macro
  um: Remove unused PGD_BOUND macro
  um: Mark setup_env_path as __init
  um: Mark install_fatal_handler as __init
  um: Mark set_stklim as __init
  um: Mark get_top_address as __init
  um: Mark parse_cache_line as __init
  um: Mark parse_host_cpu_flags as __init
  um: Count iomem_size only once in physmem calculation
  um: Remove obsolete fixmap support
  um: Remove unused MODULES_LEN macro
mm/memblock: add memblock_alloc_or_panic interface 2025-01-26T04:22:38+00:00 Guo Weikang guoweikang.kernel@gmail.com 2025-01-02T07:25:28+00:00 c6f239796b55dbc4225a6fca9f96232092b9df83 Before SLUB initialization, various subsystems used memblock_alloc to allocate memory. In most cases, when memory allocation fails, an immediate panic is required. To simplify this behavior and reduce repetitive checks, introduce `memblock_alloc_or_panic`. This function ensures that memory allocation failures result in a panic automatically, improving code readability and consistency across subsystems that require this behavior. [guoweikang.kernel@gmail.com: arch/s390: save_area_alloc default failure behavior changed to panic] Link: https://lkml.kernel.org/r/20250109033136.2845676-1-guoweikang.kernel@gmail.com Link: https://lore.kernel.org/lkml/Z2fknmnNtiZbCc7x@kernel.org/ Link: https://lkml.kernel.org/r/20250102072528.650926-1-guoweikang.kernel@gmail.com Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Before SLUB initialization, various subsystems used memblock_alloc to
allocate memory.  In most cases, when memory allocation fails, an
immediate panic is required.  To simplify this behavior and reduce
repetitive checks, introduce `memblock_alloc_or_panic`.  This function
ensures that memory allocation failures result in a panic automatically,
improving code readability and consistency across subsystems that require
this behavior.

[guoweikang.kernel@gmail.com: arch/s390: save_area_alloc default failure behavior changed to panic]
  Link: https://lkml.kernel.org/r/20250109033136.2845676-1-guoweikang.kernel@gmail.com
  Link: https://lore.kernel.org/lkml/Z2fknmnNtiZbCc7x@kernel.org/
Link: https://lkml.kernel.org/r/20250102072528.650926-1-guoweikang.kernel@gmail.com
Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
asm-generic: pgalloc: provide generic __pgd_{alloc,free} 2025-01-26T04:22:24+00:00 Kevin Brodsky kevin.brodsky@arm.com 2025-01-03T18:44:14+00:00 a9b3c355c2e6388b0a3b67627460a516d88bdbc9 We already have a generic implementation of alloc/free up to P4D level, as well as pgd_free(). Let's finish the work and add a generic PGD-level alloc helper as well. Unlike at lower levels, almost all architectures need some specific magic at PGD level (typically initialising PGD entries), so introducing a generic pgd_alloc() isn't worth it. Instead we introduce two new helpers, __pgd_alloc() and __pgd_free(), and make use of them in the arch-specific pgd_alloc() and pgd_free() wherever possible. To accommodate as many arch as possible, __pgd_alloc() takes a page allocation order. Because pagetable_alloc() allocates zeroed pages, explicit zeroing in pgd_alloc() becomes redundant and we can get rid of it. Some trivial implementations of pgd_free() also become unnecessary once __pgd_alloc() is used; remove them. Another small improvement is consistent accounting of PGD pages by using GFP_PGTABLE_{USER,KERNEL} as appropriate. Not all PGD allocations can be handled by the generic helpers. In particular, multiple architectures allocate PGDs from a kmem_cache, and those PGDs may not be page-sized. Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
We already have a generic implementation of alloc/free up to P4D level, as
well as pgd_free().  Let's finish the work and add a generic PGD-level
alloc helper as well.

Unlike at lower levels, almost all architectures need some specific magic
at PGD level (typically initialising PGD entries), so introducing a
generic pgd_alloc() isn't worth it.  Instead we introduce two new helpers,
__pgd_alloc() and __pgd_free(), and make use of them in the arch-specific
pgd_alloc() and pgd_free() wherever possible.  To accommodate as many arch
as possible, __pgd_alloc() takes a page allocation order.

Because pagetable_alloc() allocates zeroed pages, explicit zeroing in
pgd_alloc() becomes redundant and we can get rid of it.  Some trivial
implementations of pgd_free() also become unnecessary once __pgd_alloc()
is used; remove them.

Another small improvement is consistent accounting of PGD pages by using
GFP_PGTABLE_{USER,KERNEL} as appropriate.

Not all PGD allocations can be handled by the generic helpers.  In
particular, multiple architectures allocate PGDs from a kmem_cache, and
those PGDs may not be page-sized.

Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
um: Remove unused user_context function 2025-01-10T12:49:57+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:37+00:00 7ee1e43a5f493a1332af3ac668cc2a87515c1622 It's no longer used since commit 6aa802ce6acc ("uml: throw out CHOOSE_MODE"). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-10-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's no longer used since commit 6aa802ce6acc ("uml: throw out
CHOOSE_MODE").

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-10-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: Mark get_top_address as __init 2025-01-10T12:49:56+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:31+00:00 ae62ae7994a0f453b1566d04ec090cf1bd534675 It's only invoked during boot from linux_main(). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-4-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's only invoked during boot from linux_main().

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-4-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>