linux.git/arch/s390/mm, branch master

KVM: s390: Remove ptep_zap_softleaf_entry()

2026-06-02T17:31:20+00:00

Migration entries do not need to be removed.

The swap subsystem has been (and still is being) heavily reworked. The
current implementation of ptep_zap_softleaf_entry() has been slowly
modified and is now wrong, since it unconditionally calls
swap_put_entries_direct() for both swap and migration entries.

Remove ptep_zap_softleaf_entry() altogether, merge the path for proper
swap entries directly in the only caller, and ignore migration entries.

Fixes: 200197908dc4 ("KVM: s390: Refactor and split some gmap helpers")
Signed-off-by: Claudio Imbrenda 
Message-ID: <20260602142356.169458-11-imbrenda@linux.ibm.com>

KVM: s390: Avoid potentially sleeping while atomic when zapping pages

2026-06-02T14:46:41+00:00

Factor out try_get_locked_pte(), which behaves similarly to
get_locked_pte(), but does not attempt to allocate missing tables and
performs a spin_trylock() instead of blocking.

The new function is also exported, since it will be used in other
patches.

If intermediate entries are missing, there can be no pte swap entry to
free, so it's safe to ignore them.

This avoids potentially sleeping while atomic.

Fixes: e38c884df921 ("KVM: s390: Switch to new gmap")
Signed-off-by: Claudio Imbrenda 
Message-ID: <20260602142356.169458-4-imbrenda@linux.ibm.com>

s390/mm: Fix phys_to_folio() usage in do_secure_storage_access()

2026-04-28T12:45:03+00:00

In case of a Secure-Storage-Access exception the effective aka virtual
address which caused the exception is contained within the TEID.

do_secure_storage_access() incorrectly uses phys_to_folio() instead of
virt_to_folio() to translate the virtual address to the corresponding
folio.

Fix this by using virt_to_folio() instead of phys_to_folio().

Fixes: 084ea4d611a3 ("s390/mm: add (non)secure page access exceptions handlers")
Reviewed-by: Christian Borntraeger 
Reviewed-by: Claudio Imbrenda 
Signed-off-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev

mm: rename zap_page_range_single() to zap_vma_range()

2026-04-05T20:53:15+00:00

Let's rename it to make it better match our new naming scheme.

While at it, polish the kerneldoc.

[akpm@linux-foundation.org: fix rustfmtcheck]
Link: https://lkml.kernel.org/r/20260227200848.114019-15-david@kernel.org
Signed-off-by: David Hildenbrand (Arm) 
Reviewed-by: Lorenzo Stoakes (Oracle) 
Acked-by: Puranjay Mohan 
Cc: Alexander Gordeev 
Cc: Alexei Starovoitov 
Cc: Alice Ryhl 
Cc: Andrii Nakryiko 
Cc: Andy Lutomirski 
Cc: Arnaldo Carvalho de Melo 
Cc: Arnd Bergmann 
Cc: Arve 
Cc: "Borislav Petkov (AMD)" 
Cc: Carlos Llamas 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: Daniel Borkman 
Cc: Dave Airlie 
Cc: David Ahern 
Cc: David Rientjes 
Cc: David S. Miller 
Cc: Dimitri Sivanich 
Cc: Eric Dumazet 
Cc: Gerald Schaefer 
Cc: Greg Kroah-Hartman 
Cc: Hartley Sweeten 
Cc: Heiko Carstens 
Cc: Ian Abbott 
Cc: Ingo Molnar 
Cc: Jakub Kacinski 
Cc: Jani Nikula 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jarkko Sakkinen 
Cc: Jason Gunthorpe 
Cc: Jonas Lahtinen 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Madhavan Srinivasan 
Cc: Matthew Wilcox (Oracle) 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Miguel Ojeda 
Cc: Mike Rapoport 
Cc: Namhyung kim 
Cc: Neal Cardwell 
Cc: Paolo Abeni 
Cc: Pedro Falcato 
Cc: Peter Zijlstra 
Cc: Rodrigo Vivi 
Cc: Shakeel Butt 
Cc: Suren Baghdasaryan 
Cc: Todd Kjos 
Cc: Tvrtko Ursulin 
Cc: Vasily Gorbik 
Cc: Vincenzo Frascino 
Signed-off-by: Andrew Morton

mm/memory: remove "zap_details" parameter from zap_page_range_single()

2026-04-05T20:53:13+00:00

Nobody except memory.c should really set that parameter to non-NULL.  So
let's just drop it and make unmap_mapping_range_vma() use
zap_page_range_single_batched() instead.

[david@kernel.org: format on a single line]
  Link: https://lkml.kernel.org/r/8a27e9ac-2025-4724-a46d-0a7c90894ba7@kernel.org
Link: https://lkml.kernel.org/r/20260227200848.114019-3-david@kernel.org
Signed-off-by: David Hildenbrand (Arm) 
Reviewed-by: Lorenzo Stoakes (Oracle) 
Acked-by: Puranjay Mohan 
Cc: Alexander Gordeev 
Cc: Alexei Starovoitov 
Cc: Alice Ryhl 
Cc: Andrii Nakryiko 
Cc: Andy Lutomirski 
Cc: Arnaldo Carvalho de Melo 
Cc: Arnd Bergmann 
Cc: Arve 
Cc: "Borislav Petkov (AMD)" 
Cc: Carlos Llamas 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: Daniel Borkman 
Cc: Dave Airlie 
Cc: David Ahern 
Cc: David Rientjes 
Cc: David S. Miller 
Cc: Dimitri Sivanich 
Cc: Eric Dumazet 
Cc: Gerald Schaefer 
Cc: Greg Kroah-Hartman 
Cc: Hartley Sweeten 
Cc: Heiko Carstens 
Cc: Ian Abbott 
Cc: Ingo Molnar 
Cc: Jakub Kacinski 
Cc: Jani Nikula 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jarkko Sakkinen 
Cc: Jason Gunthorpe 
Cc: Jonas Lahtinen 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Madhavan Srinivasan 
Cc: Matthew Wilcox (Oracle) 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Miguel Ojeda 
Cc: Mike Rapoport 
Cc: Namhyung kim 
Cc: Neal Cardwell 
Cc: Paolo Abeni 
Cc: Pedro Falcato 
Cc: Peter Zijlstra 
Cc: Rodrigo Vivi 
Cc: Shakeel Butt 
Cc: Suren Baghdasaryan 
Cc: Todd Kjos 
Cc: Tvrtko Ursulin 
Cc: Vasily Gorbik 
Cc: Vincenzo Frascino 
Signed-off-by: Andrew Morton

mm: cache struct page for empty_zero_page and return it from ZERO_PAGE()

2026-04-05T20:53:01+00:00

For most architectures every invocation of ZERO_PAGE() does
virt_to_page(empty_zero_page).  But empty_zero_page is in BSS and it is
enough to get its struct page once at initialization time and then use it
whenever a zero page should be accessed.

Add yet another __zero_page variable that will be initialized as
virt_to_page(empty_zero_page) for most architectures in a weak
arch_setup_zero_pages() function.

For architectures that use colored zero pages (MIPS and s390) rename their
setup_zero_pages() to arch_setup_zero_pages() and make it global rather
than static.

For architectures that cannot use virt_to_page() for BSS (arm64 and
sparc64) add override of arch_setup_zero_pages().

Link: https://lkml.kernel.org/r/20260211103141.3215197-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Catalin Marinas 
Acked-by: David Hildenbrand (Arm) 
Acked-by: Liam R. Howlett 
Cc: Andreas Larsson 
Cc: "Borislav Petkov (AMD)" 
Cc: Christophe Leroy (CS GROUP) 
Cc: Dave Hansen 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Guo Ren 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Lorenzo Stoakes 
Cc: Madhavan Srinivasan 
Cc: Magnus Lindholm 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Suren Baghdasaryan 
Cc: Vineet Gupta 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

s390/mm: Add missing secure storage access fixups for donated memory

2026-03-16T15:56:28+00:00

There are special cases where secure storage access exceptions happen
in a kernel context for pages that don't have the PG_arch_1 bit
set. That bit is set for non-exported guest secure storage (memory)
but is absent on storage donated to the Ultravisor since the kernel
isn't allowed to export donated pages.

Prior to this patch we would try to export the page by calling
arch_make_folio_accessible() which would instantly return since the
arch bit is absent signifying that the page was already exported and
no further action is necessary. This leads to secure storage access
exception loops which can never be resolved.

With this patch we unconditionally try to export and if that fails we
fixup.

Fixes: 084ea4d611a3 ("s390/mm: add (non)secure page access exceptions handlers")
Reported-by: Heiko Carstens 
Suggested-by: Heiko Carstens 
Reviewed-by: Claudio Imbrenda 
Tested-by: Christian Borntraeger 
Signed-off-by: Janosch Frank 
Signed-off-by: Christian Borntraeger

s390/pfault: Fix virtual vs physical address confusion

2026-02-25T16:00:25+00:00

When Linux is running as guest, runs a user space process and the
user space process accesses a page that the host has paged out,
the guest gets a pfault interrupt and schedules a different process.
Without this mechanism the host would have to suspend the whole
virtual CPU until the page has been paged in.

To setup the pfault interrupt the real address of parameter list
should be passed to DIAGNOSE 0x258, but a virtual address is passed
instead.

That has a performance impact, since the pfault setup never succeeds,
the interrupt is never delivered to a guest and the whole virtual CPU
is suspended as result.

Cc: stable@vger.kernel.org
Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces")
Reported-by: Claudio Imbrenda 
Reviewed-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev 
Signed-off-by: Vasily Gorbik

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using

    git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook