resource: replace open coded variant of DEFINE_RES()

Replace open coded variant of DEFINE_RES(). No functional changes intended.

Link: https://lkml.kernel.org/r/20250317181412.1560630-5-andriy.shev

resource: replace open coded variant of DEFINE_RES()

Replace open coded variant of DEFINE_RES(). No functional changes intended.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: replace open coded variants of DEFINE_RES_*_NAMED()

Replace open coded variants of DEFINE_RES_*_NAMED().

Link: https://lkml.kernel.org/r/[email protected]

resource: replace open coded variants of DEFINE_RES_*_NAMED()

Replace open coded variants of DEFINE_RES_*_NAMED().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: replace open coded variant of DEFINE_RES_NAMED_DESC()

Replace open coded variant of DEFINE_RES_NAMED_DESC().

Link: https://lkml.kernel.org/r/20250317181412.1560630-3-andriy.shevchenko@lin

resource: replace open coded variant of DEFINE_RES_NAMED_DESC()

Replace open coded variant of DEFINE_RES_NAMED_DESC().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

kernel/resource: simplify API __devm_release_region() implementation

Simplify __devm_release_region() implementation by dedicated API
devres_release() which have below advantages than current
__rele

kernel/resource: simplify API __devm_release_region() implementation

Simplify __devm_release_region() implementation by dedicated API
devres_release() which have below advantages than current
__release_region() + devres_destroy():

It is simpler if __devm_release_region() is undoing what
__devm_request_region() did, otherwise, it can avoid wrong and undesired
__release_region().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zijun Hu <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Cc: Mika Westerberg <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

module: Convert symbol namespace to string literal

Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __s

module: Convert symbol namespace to string literal

Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __section("foo")") and for the same reason, it is not desired for the
namespace argument to be a macro expansion itself.

Scripted using

git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file;
do
awk -i inplace '
/^#define EXPORT_SYMBOL_NS/ {
gsub(/__stringify\(ns\)/, "ns");
print;
next;
}
/^#define MODULE_IMPORT_NS/ {
gsub(/__stringify\(ns\)/, "ns");
print;
next;
}
/MODULE_IMPORT_NS/ {
$0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g");
}
/EXPORT_SYMBOL_NS/ {
if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) {
if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ &&
$0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ &&
$0 !~ /^my/) {
getline line;
gsub(/[[:space:]]*\\$/, "");
gsub(/[[:space:]]/, "", line);
$0 = $0 " " line;
}

$0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/,
"\\1(\\2, \"\\3\")", "g");
}
}
{ print }' $file;
done

Requested-by: Masahiro Yamada <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc
Acked-by: Greg KH <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kaslr: rename physmem_end and PHYSMEM_END to direct_map_physmem_end

For clarity. It's increasingly hard to reason about the code, when KASLR
is moving around the boundaries. In this case where KAS

kaslr: rename physmem_end and PHYSMEM_END to direct_map_physmem_end

For clarity. It's increasingly hard to reason about the code, when KASLR
is moving around the boundaries. In this case where KASLR is randomizing
the location of the kernel image within physical memory, the maximum
number of address bits for physical memory has not changed.

What has changed is the ending address of memory that is allowed to be
directly mapped by the kernel.

Let's name the variable, and the associated macro accordingly.

Also, enhance the comment above the direct_map_physmem_end definition,
to further clarify how this all works.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Acked-by: Will Deacon <[email protected]>
Reviewed-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Jordan Niethe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: avoid unnecessary resource tree walking in __region_intersects()

Currently, if __region_intersects() finds any overlapped but unmatched
resource, it walks the descendant resource tree to c

resource: avoid unnecessary resource tree walking in __region_intersects()

Currently, if __region_intersects() finds any overlapped but unmatched
resource, it walks the descendant resource tree to check for overlapped
and matched descendant resources using for_each_resource(). However, in
current kernel, for_each_resource() iterates not only the descendant tree,
but also subsequent sibling trees in certain scenarios. While this
doesn't introduce bugs, it makes code hard to be understood and
potentially inefficient.

So, the patch revises next_resource() and for_each_resource() and makes
for_each_resource() traverse the subtree under the specified subtree root
only. Test shows that this avoids unnecessary resource tree walking in
__region_intersects().

For the example resource tree as follows,

X
|
A----D----E
|
B--C

if 'A' is the overlapped but unmatched resource, original kernel
iterates 'B', 'C', 'D', 'E' when it walks the descendant tree. While
the patched kernel iterates only 'B', 'C'.

Thanks David Hildenbrand for providing a good resource tree example.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Acked-by: Dan Williams <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Alison Schofield <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: correct reallocate_resource() documentation

reallocate_resource() documentation claims constraint is about "the size
and alignment" but the size is provided in another parameter. Instead

resource: correct reallocate_resource() documentation

reallocate_resource() documentation claims constraint is about "the size
and alignment" but the size is provided in another parameter. Instead of
size, constraint has the allowed memory range (min, max) so change the
wording to reflect that.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: introduce is_type_match() helper and use it

There are already a couple of places where we may replace a few lines of
code by calling a helper, which increases readability while deduplicati

resource: introduce is_type_match() helper and use it

There are already a couple of places where we may replace a few lines of
code by calling a helper, which increases readability while deduplicating
the code.

Introduce is_type_match() helper and use it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: replace open coded resource_intersection()

Patch series "resource: A couple of cleanups".

A couple of ad-hoc cleanups since there was a recent development of
the code in question. No func

resource: replace open coded resource_intersection()

Patch series "resource: A couple of cleanups".

A couple of ad-hoc cleanups since there was a recent development of
the code in question. No functional changes intended.


This patch (of 2):

__region_intersects() uses open coded resource_intersection(). Replace it
with existing API which also make more clear what we are checking.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource,kexec: walk_system_ram_res_rev must retain resource flags

walk_system_ram_res_rev() erroneously discards resource flags when passing
the information to the callback.

This causes systems wi

resource,kexec: walk_system_ram_res_rev must retain resource flags

walk_system_ram_res_rev() erroneously discards resource flags when passing
the information to the callback.

This causes systems with IORESOURCE_SYSRAM_DRIVER_MANAGED memory to have
these resources selected during kexec to store kexec buffers if that
memory happens to be at placed above normal system ram.

This leads to undefined behavior after reboot. If the kexec buffer is
never touched, nothing happens. If the kexec buffer is touched, it could
lead to a crash (like below) or undefined behavior.

Tested on a system with CXL memory expanders with driver managed memory,
TPM enabled, and CONFIG_IMA_KEXEC=y. Adding printk's showed the flags
were being discarded and as a result the check for
IORESOURCE_SYSRAM_DRIVER_MANAGED passes.

find_next_iomem_res: name(System RAM (kmem))
start(10000000000)
end(1034fffffff)
flags(83000200)

locate_mem_hole_top_down: start(10000000000) end(1034fffffff) flags(0)

[.] BUG: unable to handle page fault for address: ffff89834ffff000
[.] #PF: supervisor read access in kernel mode
[.] #PF: error_code(0x0000) - not-present page
[.] PGD c04c8bf067 P4D c04c8bf067 PUD c04c8be067 PMD 0
[.] Oops: 0000 [#1] SMP
[.] RIP: 0010:ima_restore_measurement_list+0x95/0x4b0
[.] RSP: 0018:ffffc900000d3a80 EFLAGS: 00010286
[.] RAX: 0000000000001000 RBX: 0000000000000000 RCX: ffff89834ffff000
[.] RDX: 0000000000000018 RSI: ffff89834ffff000 RDI: ffff89834ffff018
[.] RBP: ffffc900000d3ba0 R08: 0000000000000020 R09: ffff888132b8a900
[.] R10: 4000000000000000 R11: 000000003a616d69 R12: 0000000000000000
[.] R13: ffffffff8404ac28 R14: 0000000000000000 R15: ffff89834ffff000
[.] FS: 0000000000000000(0000) GS:ffff893d44640000(0000) knlGS:0000000000000000
[.] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[.] ata5: SATA link down (SStatus 0 SControl 300)
[.] CR2: ffff89834ffff000 CR3: 000001034d00f001 CR4: 0000000000770ef0
[.] PKRU: 55555554
[.] Call Trace:
[.] <TASK>
[.] ? __die+0x78/0xc0
[.] ? page_fault_oops+0x2a8/0x3a0
[.] ? exc_page_fault+0x84/0x130
[.] ? asm_exc_page_fault+0x22/0x30
[.] ? ima_restore_measurement_list+0x95/0x4b0
[.] ? template_desc_init_fields+0x317/0x410
[.] ? crypto_alloc_tfm_node+0x9c/0xc0
[.] ? init_ima_lsm+0x30/0x30
[.] ima_load_kexec_buffer+0x72/0xa0
[.] ima_init+0x44/0xa0
[.] __initstub__kmod_ima__373_1201_init_ima7+0x1e/0xb0
[.] ? init_ima_lsm+0x30/0x30
[.] do_one_initcall+0xad/0x200
[.] ? idr_alloc_cyclic+0xaa/0x110
[.] ? new_slab+0x12c/0x420
[.] ? new_slab+0x12c/0x420
[.] ? number+0x12a/0x430
[.] ? sysvec_apic_timer_interrupt+0xa/0x80
[.] ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[.] ? parse_args+0xd4/0x380
[.] ? parse_args+0x14b/0x380
[.] kernel_init_freeable+0x1c1/0x2b0
[.] ? rest_init+0xb0/0xb0
[.] kernel_init+0x16/0x1a0
[.] ret_from_fork+0x2f/0x40
[.] ? rest_init+0xb0/0xb0
[.] ret_from_fork_asm+0x11/0x20
[.] </TASK>

Link: https://lore.kernel.org/all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 7acf164b259d ("resource: add walk_system_ram_res_rev()")
Signed-off-by: Gregory Price <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: AKASHI Takahiro <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Cc: Mika Westerberg <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource, kunit: add test case for region_intersects()

Patch series "resource: Fix region_intersects() vs
add_memory_driver_managed()", v3.

The patchset fixes a bug of region_intersects() for syste

resource, kunit: add test case for region_intersects()

Patch series "resource: Fix region_intersects() vs
add_memory_driver_managed()", v3.

The patchset fixes a bug of region_intersects() for systems with CXL
memory. The details of the bug can be found in [1/3]. To avoid similar
bugs in the future. A kunit test case for region_intersects() is added in
[3/3]. [2/3] is a preparation patch for [3/3].


This patch (of 3):

region_intersects() is important because it's used for /dev/mem permission
checking. To avoid possible bug of region_intersects() in the future, a
kunit test case for region_intersects() is added.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Alison Schofield <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Baoquan He <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: make alloc_free_mem_region() works for iomem_resource

During developing a kunit test case for region_intersects(), some fake
resources need to be inserted into iomem_resource. To do that,

resource: make alloc_free_mem_region() works for iomem_resource

During developing a kunit test case for region_intersects(), some fake
resources need to be inserted into iomem_resource. To do that, a resource
hole needs to be found first in iomem_resource.

However, alloc_free_mem_region() cannot work for iomem_resource now.
Because the start address to check cannot be 0 to detect address wrapping
0 in gfr_continue(), while iomem_resource.start == 0. To make
alloc_free_mem_region() works for iomem_resource, gfr_start() is changed
to avoid to return 0 even if base->start == 0. We don't need to check 0
as start address.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Alison Schofield <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Baoquan He <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

resource: fix region_intersects() vs add_memory_driver_managed()

On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.

490000000-50f

resource: fix region_intersects() vs add_memory_driver_managed()

On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.

490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)

Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.

For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,

$ dd if=data of=/dev/mem bs=$((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s

the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.

ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53

The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.

So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.

In the new implementation, an example resource tree

|------------- "CXL Window 0" ------------|
|-- "System RAM" --|

will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),

|-- "System RAM" --||-- "CXL Window 0a" --|

Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".

Link: https://lkml.kernel.org/r/[email protected]
Fixes: c221c0b0308f ("device-dax: "Hotplug" persistent memory for use like normal RAM")
Signed-off-by: "Huang, Ying" <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Alison Schofield <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: kvmalloc: align kvrealloc() with krealloc()

Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior

mm: kvmalloc: align kvrealloc() with krealloc()

Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:

- krealloc() frees the memory when the requested size is zero, whereas
kvrealloc() simply returns a pointer to the existing allocation.

- krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
kvrealloc() does not accept a NULL pointer at all and, if passed,
would fault instead.

- krealloc() is self-contained, whereas kvrealloc() relies on the caller
to provide the size of the previous allocation.

Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.

Besides that, implementing kvrealloc() by making use of krealloc() and
vrealloc() provides oppertunities to grow (and shrink) allocations more
efficiently. For instance, vrealloc() can be optimized to allocate and
map additional pages to grow the allocation or unmap and free unused pages
to shrink the allocation.

[[email protected]: document concurrency restrictions]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: disable KASAN when switching to vmalloc]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: properly document __GFP_ZERO behavior]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Danilo Krummrich <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Chandan Babu R <[email protected]>
Cc: Christian König <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Oliver Upton <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Uladzislau Rezki <[email protected]>
Cc: Wedson Almeida Filho <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

x86/kaslr: Expose and use the end of the physical memory address space

iounmap() on x86 occasionally fails to unmap because the provided valid
ioremap address is not below high_memory. It turned out

x86/kaslr: Expose and use the end of the physical memory address space

iounmap() on x86 occasionally fails to unmap because the provided valid
ioremap address is not below high_memory. It turned out that this
happens due to KASLR.

KASLR uses the full address space between PAGE_OFFSET and vaddr_end to
randomize the starting points of the direct map, vmalloc and vmemmap
regions. It thereby limits the size of the direct map by using the
installed memory size plus an extra configurable margin for hot-plug
memory. This limitation is done to gain more randomization space
because otherwise only the holes between the direct map, vmalloc,
vmemmap and vaddr_end would be usable for randomizing.

The limited direct map size is not exposed to the rest of the kernel, so
the memory hot-plug and resource management related code paths still
operate under the assumption that the available address space can be
determined with MAX_PHYSMEM_BITS.

request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1
downwards. That means the first allocation happens past the end of the
direct map and if unlucky this address is in the vmalloc space, which
causes high_memory to become greater than VMALLOC_START and consequently
causes iounmap() to fail for valid ioremap addresses.

MAX_PHYSMEM_BITS cannot be changed for that because the randomization
does not align with address bit boundaries and there are other places
which actually require to know the maximum number of address bits. All
remaining usage sites of MAX_PHYSMEM_BITS have been analyzed and found
to be correct.

Cure this by exposing the end of the direct map via PHYSMEM_END and use
that for the memory hot-plug and resource management related places
instead of relying on MAX_PHYSMEM_BITS. In the KASLR case PHYSMEM_END
maps to a variable which is initialized by the KASLR initialization and
otherwise it is based on MAX_PHYSMEM_BITS as before.

To prevent future hickups add a check into add_pages() to catch callers
trying to add memory above PHYSMEM_END.

Fixes: 0483e1fa6e09 ("x86/mm: Implement ASLR for kernel memory regions")
Reported-by: Max Ramanouski <[email protected]>
Reported-by: Alistair Popple <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-By: Max Ramanouski <[email protected]>
Tested-by: Alistair Popple <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/all/87ed6soy3z.ffs@tglx

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resource: Export find_resource_space()

PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty space big enough to fit the window.

Export find_resource_sp

resource: Export find_resource_space()

PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty space big enough to fit the window.

Export find_resource_space() for the purpose. Also move the struct
resource_constraint into generic header to be able to use the new
interface.

Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

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resource: Handle simple alignment inside __find_resource_space()

allocate_resource() accepts ->alignf() callback to perform custom alignment
beyond constraint->align. If alignf is NULL, simple_align

resource: Handle simple alignment inside __find_resource_space()

allocate_resource() accepts ->alignf() callback to perform custom alignment
beyond constraint->align. If alignf is NULL, simple_align_resource() is
used which only returns avail->start (no change).

Using avail->start directly is natural and can be done with a conditional
in __find_resource_space() instead which avoids unnecessarily using
callback. It makes the code inside __find_resource_space() more obvious and
removes the need for the caller to provide constraint->alignf
unnecessarily.

This is preparation for exporting find_resource_space().

Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

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resource: Use typedef for alignf callback

To make it simpler to declare resource constraint alignf callbacks, add
typedef for it and document it.

Suggested-by: Andy Shevchenko <andriy.shevchenko@li

resource: Use typedef for alignf callback

To make it simpler to declare resource constraint alignf callbacks, add
typedef for it and document it.

Suggested-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

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resource: Document find_resource_space() and resource_constraint

Document find_resource_space() and the struct resource_constraint as they
are going to be exposed outside of resource.c.

Link: https

resource: Document find_resource_space() and resource_constraint

Document find_resource_space() and the struct resource_constraint as they
are going to be exposed outside of resource.c.

Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

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resource: Rename find_resource() to find_resource_space()

Rename find_resource() to find_resource_space() to better describe what the
function does. This is a preparation for exposing it beyond reso

resource: Rename find_resource() to find_resource_space()

Rename find_resource() to find_resource_space() to better describe what the
function does. This is a preparation for exposing it beyond resource.c,
which is needed by PCI core. Also rename the __ variant to match the names.

Link: https://lore.kernel.org/r/[email protected]
Tested-by: Lidong Wang <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

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resource: add walk_system_ram_res_rev()

This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks

resource: add walk_system_ram_res_rev()

This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks through a list of all the resources of System RAM in
reversed order, i.e., from higher to lower.

It will be used in kexec_file code to load kernel, initrd etc when
preparing kexec reboot.

Link: https://lkml.kernel.org/r/ZVTA6z/06cLnWKUz@MiWiFi-R3L-srv
Signed-off-by: AKASHI Takahiro <[email protected]>
Signed-off-by: Baoquan He <[email protected]>
Cc: Eric Biederman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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kernel/resource: Increment by align value in get_free_mem_region()

Currently get_free_mem_region() searches for available capacity
in increments equal to the region size being requested. This can
ca

kernel/resource: Increment by align value in get_free_mem_region()

Currently get_free_mem_region() searches for available capacity
in increments equal to the region size being requested. This can
cause the search to take giant steps through the resource leaving
needless gaps and missing available space.

Specifically 'cxl create-region' fails with ERANGE even though capacity
of the given size and CXL's expected 256M x InterleaveWays alignment can
be satisfied.

Replace the total-request-size increment with a next alignment increment
so that the next possible address is always examined for availability.

Fixes: 14b80582c43e ("resource: Introduce alloc_free_mem_region()")
Reported-by: Dmytro Adamenko <[email protected]>
Reported-by: Dan Williams <[email protected]>
Signed-off-by: Alison Schofield <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Cc: Jason Gunthorpe <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Dan Williams <[email protected]>

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resource: Unify next_resource() and next_resource_skip_children()

We have the next_resource() is used once and no user for the
next_resource_skip_children() outside of the for_each_resource().

Unif

resource: Unify next_resource() and next_resource_skip_children()

We have the next_resource() is used once and no user for the
next_resource_skip_children() outside of the for_each_resource().

Unify them by adding skip_children parameter to the next_resource().

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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resource: Reuse for_each_resource() macro

We have a few places where for_each_resource() is open coded.
Replace that by the macro. This makes code easier to read and
understand.

With this, compile

resource: Reuse for_each_resource() macro

We have a few places where for_each_resource() is open coded.
Replace that by the macro. This makes code easier to read and
understand.

With this, compile r_next() only for CONFIG_PROC_FS=y.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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