Merge tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 memory management updates from Thomas Gleixner:

- Make LAM enablement safe vs. kernel threads using

Merge tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 memory management updates from Thomas Gleixner:

- Make LAM enablement safe vs. kernel threads using a process mm
temporarily as switching back to the process would not update CR3 and
therefore not enable LAM causing faults in user space when using
tagged pointers. Cure it by synchronizing LAM enablement via IPIs to
all CPUs which use the related mm.

- Cure a LAM harmless inconsistency between CR3 and the state during
context switch. It's both confusing and prone to lead to real bugs

- Handle alt stack handling for threads which run with a non-zero
protection key. The non-zero key prevents the kernel to access the
alternate stack. Cure it by temporarily enabling all protection keys
for the alternate stack setup/restore operations.

- Provide a EFI config table identity mapping for kexec kernel to
prevent kexec fails because the new kernel cannot access the config
table array

- Use GB pages only when a full GB is mapped in the identity map as
otherwise the CPU can speculate into reserved areas after the end of
memory which causes malfunction on UV systems.

- Remove the noisy and pointless SRAT table dump during boot

- Use is_ioremap_addr() for iounmap() address range checks instead of
high_memory. is_ioremap_addr() is more precise.

* tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioremap: Improve iounmap() address range checks
x86/mm: Remove duplicate check from build_cr3()
x86/mm: Remove unused NX related declarations
x86/mm: Remove unused CR3_HW_ASID_BITS
x86/mm: Don't print out SRAT table information
x86/mm/ident_map: Use gbpages only where full GB page should be mapped.
x86/kexec: Add EFI config table identity mapping for kexec kernel
selftests/mm: Add new testcases for pkeys
x86/pkeys: Restore altstack access in sigreturn()
x86/pkeys: Update PKRU to enable all pkeys before XSAVE
x86/pkeys: Add helper functions to update PKRU on the sigframe
x86/pkeys: Add PKRU as a parameter in signal handling functions
x86/mm: Cleanup prctl_enable_tagged_addr() nr_bits error checking
x86/mm: Fix LAM inconsistency during context switch
x86/mm: Use IPIs to synchronize LAM enablement

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x86/pkeys: Update PKRU to enable all pkeys before XSAVE

If the alternate signal stack is protected by a different PKEY than the
current execution stack, copying XSAVE data to the sigaltstack will fa

x86/pkeys: Update PKRU to enable all pkeys before XSAVE

If the alternate signal stack is protected by a different PKEY than the
current execution stack, copying XSAVE data to the sigaltstack will fail
if its PKEY is not enabled in the PKRU register.

It's unknown which pkey was used by the application for the altstack, so
enable all PKEYS before XSAVE.

But this updated PKRU value is also pushed onto the sigframe, which
means the register value restored from sigcontext will be different from
the user-defined one, which is incorrect.

Fix that by overwriting the PKRU value on the sigframe with the original,
user-defined PKRU.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240802061318.2140081-4-aruna.ramakrishna@oracle.com

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x86/pkeys: Add helper functions to update PKRU on the sigframe

In the case where a user thread sets up an alternate signal stack protected
by the default PKEY (i.e. PKEY 0), while the thread's stack

x86/pkeys: Add helper functions to update PKRU on the sigframe

In the case where a user thread sets up an alternate signal stack protected
by the default PKEY (i.e. PKEY 0), while the thread's stack is protected by
a non-zero PKEY, both these PKEYS have to be enabled in the PKRU register
for the signal to be delivered to the application correctly. However, the
PKRU value restored after handling the signal must not enable this extra
PKEY (i.e. PKEY 0) - i.e., the PKRU value in the sigframe has to be
overwritten with the user-defined value.

Add helper functions that will update PKRU value in the sigframe after
XSAVE.

Note that sig_prepare_pkru() makes no assumption about which PKEY could
be used to protect the altstack (i.e. it may not be part of init_pkru),
and so enables all PKEYS.

No functional change.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240802061318.2140081-3-aruna.ramakrishna@oracle.com

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x86/pkeys: Add PKRU as a parameter in signal handling functions

Assume there's a multithreaded application that runs untrusted user
code. Each thread has its stack/code protected by a non-zero PKEY,

x86/pkeys: Add PKRU as a parameter in signal handling functions

Assume there's a multithreaded application that runs untrusted user
code. Each thread has its stack/code protected by a non-zero PKEY, and the
PKRU register is set up such that only that particular non-zero PKEY is
enabled. Each thread also sets up an alternate signal stack to handle
signals, which is protected by PKEY zero. The PKEYs man page documents that
the PKRU will be reset to init_pkru when the signal handler is invoked,
which means that PKEY zero access will be enabled. But this reset happens
after the kernel attempts to push fpu state to the alternate stack, which
is not (yet) accessible by the kernel, which leads to a new SIGSEGV being
sent to the application, terminating it.

Enabling both the non-zero PKEY (for the thread) and PKEY zero in
userspace will not work for this use case. It cannot have the alt stack
writeable by all - the rationale here is that the code running in that
thread (using a non-zero PKEY) is untrusted and should not have access
to the alternate signal stack (that uses PKEY zero), to prevent the
return address of a function from being changed. The expectation is that
kernel should be able to set up the alternate signal stack and deliver
the signal to the application even if PKEY zero is explicitly disabled
by the application. The signal handler accessibility should not be
dictated by whatever PKRU value the thread sets up.

The PKRU register is managed by XSAVE, which means the sigframe contents
must match the register contents - which is not the case here. It's
required that the signal frame contains the user-defined PKRU value (so
that it is restored correctly from sigcontext) but the actual register must
be reset to init_pkru so that the alt stack is accessible and the signal
can be delivered to the application. It seems that the proper fix here
would be to remove PKRU from the XSAVE framework and manage it separately,
which is quite complicated. As a workaround, do this:

orig_pkru = rdpkru();
wrpkru(orig_pkru & init_pkru_value);
xsave_to_user_sigframe();
put_user(pkru_sigframe_addr, orig_pkru)

In preparation for writing PKRU to sigframe, pass PKRU as an additional
parameter down the call chain from get_sigframe().

No functional change.

Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240802061318.2140081-2-aruna.ramakrishna@oracle.com

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Merge branch 'next' into for-linus

Prepare input updates for 6.11 merge window.

Merge tag 'v6.9' into next

Sync up with the mainline to bring in the new cleanup API.

Merge drm/drm-next into drm-intel-gt-next

Some display refactoring patches are needed in order to allow conflict-
less merging.

Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>

Merge drm/drm-next into drm-intel-next

Sync to get the drm_printer changes to drm-intel-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge tag 'drm-misc-next-2024-02-08' into msm-next

Merge the drm-misc tree to uprev MSM CI.

Signed-off-by: Rob Clark <robdclark@chromium.org>

Merge drm/drm-next into drm-misc-next

Kickstart 6.9 development cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-xe-next

Sync to v6.8-rc1.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@k

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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Merge branch 'linus' into x86/mm, to refresh the branch and pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'master' into mm-hotfixes-stable

Merge v6.8-rc1 into drm-misc-fixes

Let's kickstart the 6.8 fix cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-intel-gt-next

Work that needs to land in drm-intel-gt-next depends on two patches only
present in drm-intel-next, absence of which is causing a merge conflict:

3b918f4

Merge drm/drm-next into drm-intel-gt-next

Work that needs to land in drm-intel-gt-next depends on two patches only
present in drm-intel-next, absence of which is causing a merge conflict:

3b918f4f0c8b ("drm/i915/pxp: Optimize GET_PARAM:PXP_STATUS")
ac765b7018f6 ("drm/i915/pxp/mtl: intel_pxp_init_hw needs runtime-pm inside pm-complete")

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

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Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs

Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thin

Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs

Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.

This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"

* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...

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rseq: Split out rseq.h from sched.h

We're trying to get sched.h down to more or less just types only, not
code - rseq can live in its own header.

This helps us kill the dependency on preempt.h in s

rseq: Split out rseq.h from sched.h

We're trying to get sched.h down to more or less just types only, not
code - rseq can live in its own header.

This helps us kill the dependency on preempt.h in sched.h.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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Merge branch 'next' into for-linus

Prepare input updates for 6.7 merge window.

Merge branch 'linus' into smp/core

Pull in upstream to get the fixes so depending changes can be applied.

Merge drm/drm-next into drm-misc-next

Updating drm-misc-next to the state of Linux v6.6-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'v6.6-rc4' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v6.6-rc2' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge drm/drm-next into drm-intel-next

Sync to v6.6-rc1.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>