Peter Xu [Mon, 25 Jul 2022 14:20:46 +0000 (10:20 -0400)]
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
Patch series "mm/mprotect: Fix soft-dirty checks", v4.
This patch (of 3):
The check wanted to make sure when soft-dirty tracking is enabled we won't
grant write bit by accident, as a page fault is needed for dirty tracking.
The intention is correct but we didn't check it right because
VM_SOFTDIRTY set actually means soft-dirty tracking disabled. Fix it.
There's another thing tricky about soft-dirty is that, we can't check the
vma flag !(vma_flags & VM_SOFTDIRTY) directly but only check it after we
checked CONFIG_MEM_SOFT_DIRTY because otherwise VM_SOFTDIRTY will be
defined as zero, and !(vma_flags & VM_SOFTDIRTY) will constantly return
true. To avoid misuse, introduce a helper for checking whether vma has
soft-dirty tracking enabled.
We can easily verify this with any exclusive anonymous page, like program
below:
Here we attach a Fixes to commit 64fe24a3e05e only for easy tracking, as
this patch won't apply to a tree before that point. However the commit
wasn't the source of problem, but instead 64e455079e1b. It's just that
after 64fe24a3e05e anonymous memory will also suffer from this problem
with mprotect().
syzbot is reporting GFP_KERNEL allocation with oom_lock held when
reporting memcg OOM [1]. If this allocation triggers the global OOM
situation then the system can livelock because the GFP_KERNEL
allocation with oom_lock held cannot trigger the global OOM killer
because __alloc_pages_may_oom() fails to hold oom_lock.
Fix this problem by removing the allocation from memory_stat_format()
completely, and pass static buffer when calling from memcg OOM path.
Note that the caller holding filesystem lock was the trigger for syzbot
to report this locking dependency. Doing GFP_KERNEL allocation with
filesystem lock held can deadlock the system even without involving OOM
situation.
Shiyang Ruan [Thu, 9 Jun 2022 14:34:35 +0000 (22:34 +0800)]
xfs: fail dax mount if reflink is enabled on a partition
Failure notification is not supported on partitions. So, when we mount a
reflink enabled xfs on a partition with dax option, let it fail with
-EINVAL code.
Jiebin Sun [Fri, 22 Jul 2022 16:49:49 +0000 (00:49 +0800)]
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
Remove the redundant updating of stats_flush_threshold. If the global var
stats_flush_threshold has exceeded the trigger value for
__mem_cgroup_flush_stats, further increment is unnecessary.
Apply the patch and test the pts/hackbench-1.0.0 Count:4 (160 threads).
Score gain: 1.95x
Reduce CPU cycles in __mod_memcg_lruvec_state (44.88% -> 0.12%)
CPU: ICX 8380 x 2 sockets
Core number: 40 x 2 physical cores
Benchmark: pts/hackbench-1.0.0 Count:4 (160 threads)
Axel Rasmussen [Fri, 22 Jul 2022 20:15:13 +0000 (13:15 -0700)]
userfaultfd: don't fail on unrecognized features
The basic interaction for setting up a userfaultfd is, userspace issues
a UFFDIO_API ioctl, and passes in a set of zero or more feature flags,
indicating the features they would prefer to use.
Of course, different kernels may support different sets of features
(depending on kernel version, kconfig options, architecture, etc).
Userspace's expectations may also not match: perhaps it was built
against newer kernel headers, which defined some features the kernel
it's running on doesn't support.
Currently, if userspace passes in a flag we don't recognize, the
initialization fails and we return -EINVAL. This isn't great, though.
Userspace doesn't have an obvious way to react to this; sure, one of the
features I asked for was unavailable, but which one? The only option it
has is to turn off things "at random" and hope something works.
Instead, modify UFFDIO_API to just ignore any unrecognized feature
flags. The interaction is now that the initialization will succeed, and
as always we return the *subset* of feature flags that can actually be
used back to userspace.
Now userspace has an obvious way to react: it checks if any flags it
asked for are missing. If so, it can conclude this kernel doesn't
support those, and it can either resign itself to not using them, or
fail with an error on its own, or whatever else.
Miaohe Lin [Sat, 23 Jul 2022 07:38:04 +0000 (15:38 +0800)]
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
We forget to set cft->private for numa stat file. As a result, numa stat
of hstates[0] is always showed for all hstates. Encode the hstates index
into cft->private to fix this issue.
Kassey Li [Tue, 19 Jul 2022 09:15:54 +0000 (17:15 +0800)]
mm/cma_debug.c: align the name buffer length as struct cma
Avoids truncating the debugfs output to 16 chars. Potentially alters
the userspace output, but this is a debugfs interface and there are no
stability guarantees.
This code just reads from memory without caring about the data itself.
However static checkers complain that "tmp" is never properly initialized.
Initialize it to zero and change the name to "dummy" to show that we
don't care about the value stored in it.
Miaohe Lin [Tue, 19 Jul 2022 11:52:33 +0000 (19:52 +0800)]
mm/mempolicy: remove unneeded out label
We can use unlock label to unlock ptl and return ret directly to remove
the unneeded out label and reduce the size of mempolicy.o. No functional
change intended.
[Before]
text data bss dec hex filename
26702 3972 6168 36842 8fea mm/mempolicy.o
[After]
text data bss dec hex filename
26662 3972 6168 36802 8fc2 mm/mempolicy.o
mm/page_alloc: correct the wrong cpuset file path in comment
cpuset.c was moved to kernel/cgroup/ in below commit 201af4c0fab0 ("cgroup: move cgroup files under kernel/cgroup/")
Correct the wrong path in comment.
Jianglei Nie [Thu, 14 Jul 2022 06:37:46 +0000 (14:37 +0800)]
mm/damon/reclaim: fix potential memory leak in damon_reclaim_init()
damon_reclaim_init() allocates a memory chunk for ctx with
damon_new_ctx(). When damon_select_ops() fails, ctx is not released,
which will lead to a memory leak.
We should release the ctx with damon_destroy_ctx() when damon_select_ops()
fails to fix the memory leak.
Yosry Ahmed [Thu, 14 Jul 2022 06:49:18 +0000 (06:49 +0000)]
mm: vmpressure: don't count proactive reclaim in vmpressure
memory.reclaim is a cgroup v2 interface that allows users to proactively
reclaim memory from a memcg, without real memory pressure. Reclaim
operations invoke vmpressure, which is used: (a) To notify userspace of
reclaim efficiency in cgroup v1, and (b) As a signal for a memcg being
under memory pressure for networking (see
mem_cgroup_under_socket_pressure()).
For (a), vmpressure notifications in v1 are not affected by this change
since memory.reclaim is a v2 feature.
For (b), the effects of the vmpressure signal (according to Shakeel [1])
are as follows:
1. Reducing send and receive buffers of the current socket.
2. May drop packets on the rx path.
3. May throttle current thread on the tx path.
Since proactive reclaim is invoked directly by userspace, not by memory
pressure, it makes sense not to throttle networking. Hence, this change
makes sure that proactive reclaim caused by memory.reclaim does not
trigger vmpressure.
zs_malloc returns 0 if it fails. zs_zpool_malloc will return -1 when
zs_malloc return 0. But -1 makes the return value unclear.
For example, when zswap_frontswap_store calls zs_malloc through
zs_zpool_malloc, it will return -1 to its caller. The other return value
is -EINVAL, -ENODEV or something else.
This commit changes zs_malloc to return ERR_PTR on failure. It didn't
just let zs_zpool_malloc return -ENOMEM becaue zs_malloc has two types of
failure:
- size is not OK return -EINVAL
- memory alloc fail return -ENOMEM.
Zhou Guanghui [Wed, 15 Jun 2022 10:27:42 +0000 (10:27 +0000)]
memblock,arm64: expand the static memblock memory table
In a system(Huawei Ascend ARM64 SoC) using HBM, a multi-bit ECC error
occurs, and the BIOS will mark the corresponding area (for example, 2 MB)
as unusable. When the system restarts next time, these areas are not
reported or reported as EFI_UNUSABLE_MEMORY. Both cases lead to an
increase in the number of memblocks, whereas EFI_UNUSABLE_MEMORY leads to
a larger number of memblocks.
For example, if the EFI_UNUSABLE_MEMORY type is reported:
...
memory[0x92] [0x0000200834a00000-0x0000200835bfffff], 0x0000000001200000 bytes on node 7 flags: 0x0
memory[0x93] [0x0000200835c00000-0x0000200835dfffff], 0x0000000000200000 bytes on node 7 flags: 0x4
memory[0x94] [0x0000200835e00000-0x00002008367fffff], 0x0000000000a00000 bytes on node 7 flags: 0x0
memory[0x95] [0x0000200836800000-0x00002008369fffff], 0x0000000000200000 bytes on node 7 flags: 0x4
memory[0x96] [0x0000200836a00000-0x0000200837bfffff], 0x0000000001200000 bytes on node 7 flags: 0x0
memory[0x97] [0x0000200837c00000-0x0000200837dfffff], 0x0000000000200000 bytes on node 7 flags: 0x4
memory[0x98] [0x0000200837e00000-0x000020087fffffff], 0x0000000048200000 bytes on node 7 flags: 0x0
memory[0x99] [0x0000200880000000-0x0000200bcfffffff], 0x0000000350000000 bytes on node 6 flags: 0x0
memory[0x9a] [0x0000200bd0000000-0x0000200bd01fffff], 0x0000000000200000 bytes on node 6 flags: 0x4
memory[0x9b] [0x0000200bd0200000-0x0000200bd07fffff], 0x0000000000600000 bytes on node 6 flags: 0x0
memory[0x9c] [0x0000200bd0800000-0x0000200bd09fffff], 0x0000000000200000 bytes on node 6 flags: 0x4
memory[0x9d] [0x0000200bd0a00000-0x0000200fcfffffff], 0x00000003ff600000 bytes on node 6 flags: 0x0
memory[0x9e] [0x0000200fd0000000-0x0000200fd01fffff], 0x0000000000200000 bytes on node 6 flags: 0x4
memory[0x9f] [0x0000200fd0200000-0x0000200fffffffff], 0x000000002fe00000 bytes on node 6 flags: 0x0
...
The EFI memory map is parsed to construct the memblock arrays before the
memblock arrays can be resized. As the result, memory regions beyond
INIT_MEMBLOCK_REGIONS are lost.
Add a new macro INIT_MEMBLOCK_MEMORY_REGIONS to replace
INIT_MEMBLOCK_REGTIONS to define the size of the static memblock.memory
array.
Allow overriding memblock.memory array size with architecture defined
INIT_MEMBLOCK_MEMORY_REGIONS and make arm64 to set
INIT_MEMBLOCK_MEMORY_REGIONS to 1024 when CONFIG_EFI is enabled.
Miaohe Lin [Sat, 16 Jul 2022 08:03:59 +0000 (16:03 +0800)]
mm: remove obsolete comment in do_fault_around()
Since commit 7267ec008b5c ("mm: postpone page table allocation until we
have page to map"), do_fault_around is not called with page table lock
held. Cleanup the corresponding comments.
William Lam [Mon, 11 Jul 2022 20:28:06 +0000 (21:28 +0100)]
mm: compaction: include compound page count for scanning in pageblock isolation
The number of scanned pages can be lower than the number of isolated pages
when isolating mirgratable or free pageblock. The metric is being
reported in trace event and also used in vmstat.
some example output from trace where it shows nr_taken can be greater
than nr_scanned:
mm_compaction_isolate_migratepages does not seem to have this
behaviour, but for the reason of consistency, nr_scanned should also be
taken care of in that side.
This behaviour is confusing since currently the count for isolated pages
takes account of compound page but not for the case of scanned pages. And
given that the number of isolated pages(nr_taken) reported in
mm_compaction_isolate_template trace event is on a single-page basis, the
ambiguity when reporting the number of scanned pages can be removed by
also including compound page count.
Adam Sindelar [Mon, 4 Jul 2022 12:38:13 +0000 (14:38 +0200)]
selftests/vm: skip 128TBswitch on unsupported arch
The test va_128TBswitch.c exercises a feature only supported on PPC and
x86_64, but it's run on other 64-bit archs as well. Before this patch,
the test did nothing and returned 0 for KSFT_PASS. This patch makes it
return the KSFT codes from kselftest.h, including KSFT_SKIP when
appropriate.
Roman Gushchin [Sat, 2 Jul 2022 03:35:21 +0000 (20:35 -0700)]
mm: memcontrol: do not miss MEMCG_MAX events for enforced allocations
Yafang Shao reported an issue related to the accounting of bpf memory:
if a bpf map is charged indirectly for memory consumed from an
interrupt context and allocations are enforced, MEMCG_MAX events are
not raised.
It's not/less of an issue in a generic case because consequent
allocations from a process context will trigger the direct reclaim and
MEMCG_MAX events will be raised. However a bpf map can belong to a
dying/abandoned memory cgroup, so there will be no allocations from a
process context and no MEMCG_MAX events will be triggered.
Miaohe Lin [Mon, 27 Jun 2022 13:23:51 +0000 (21:23 +0800)]
filemap: minor cleanup for filemap_write_and_wait_range
Restructure the logic in filemap_write_and_wait_range to simplify the code
and make it more consistent with file_write_and_wait_range. No functional
change intended.
Miaohe Lin [Sat, 18 Jun 2022 08:20:27 +0000 (16:20 +0800)]
mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region
Since the beginning, charged is set to 0 to avoid calling vm_unacct_memory
twice because vm_unacct_memory will be called by above unmap_region. But
since commit 4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from
the unmap_vmas() interfaces"), unmap_region doesn't call vm_unacct_memory
anymore. So charged shouldn't be set to 0 now otherwise the calling to
paired vm_unacct_memory will be missed and leads to imbalanced account.
Liam Howlett [Mon, 27 Jun 2022 15:18:59 +0000 (15:18 +0000)]
android: binder: fix lockdep check on clearing vma
When munmapping a vma, the mmap_lock can be degraded to a write before
calling close() on the file handle. The binder close() function calls
binder_alloc_set_vma() to clear the vma address, which now has a lock dep
check for writing on the mmap_lock. Change the lockdep check to ensure
the reading lock is held while clearing and keep the write check while
writing.
Liam R. Howlett [Tue, 21 Jun 2022 01:09:09 +0000 (21:09 -0400)]
android: binder: stop saving a pointer to the VMA
Do not record a pointer to a VMA outside of the mmap_lock for later use.
This is unsafe and there are a number of failure paths *after* the
recorded VMA pointer may be freed during setup. There is no callback to
the driver to clear the saved pointer from generic mm code. Furthermore,
the VMA pointer may become stale if any number of VMA operations end up
freeing the VMA so saving it was fragile to being with.
Instead, change the binder_alloc struct to record the start address of the
VMA and use vma_lookup() to get the vma when needed. Add lockdep
mmap_lock checks on updates to the vma pointer to ensure the lock is held
and depend on that lock for synchronization of readers and writers - which
was already the case anyways, so the smp_wmb()/smp_rmb() was not
necessary.
syzbot is reporting double kfree() at free_prealloced_shrinker() [1], for
destroy_unused_super() calls free_prealloced_shrinker() even if
prealloc_shrinker() returned an error. Explicitly clear shrinker name
when prealloc_shrinker() called kfree().
bdi_sched_wait() is no longer used since commit 839a8e8660b6 ("writeback:
replace custom worker pool implementation with unbound workqueue"), so
remove it.
Miaohe Lin [Sat, 9 Jul 2022 09:25:27 +0000 (17:25 +0800)]
mm/mmap: fix obsolete comment of find_extend_vma
mmget_still_valid() has already been removed via commit 4d45e75a9955 ("mm:
remove the now-unnecessary mmget_still_valid() hack"). Update the
corresponding comment.
mm/page_alloc: use try_cmpxchg in set_pfnblock_flags_mask
Use try_cmpxchg instead of cmpxchg in set_pfnblock_flags_mask. x86
CMPXCHG instruction returns success in ZF flag, so this change saves a
compare after cmpxchg (and related move instruction in front of cmpxchg).
The main loop improves from:
1c5d: 48 89 c2 mov %rax,%rdx
1c60: 48 89 c1 mov %rax,%rcx
1c63: 48 21 fa and %rdi,%rdx
1c66: 4c 09 c2 or %r8,%rdx
1c69: f0 48 0f b1 16 lock cmpxchg %rdx,(%rsi)
1c6e: 48 39 c1 cmp %rax,%rcx
1c71: 75 ea jne 1c5d <...>
to:
1c60: 48 89 ca mov %rcx,%rdx
1c63: 48 21 c2 and %rax,%rdx
1c66: 4c 09 c2 or %r8,%rdx
1c69: f0 48 0f b1 16 lock cmpxchg %rdx,(%rsi)
1c6e: 75 f0 jne 1c60 <...>
Gang Li [Wed, 6 Jul 2022 03:46:54 +0000 (11:46 +0800)]
mm, hugetlb: skip irrelevant nodes in show_free_areas()
show_free_areas() allows to filter out node specific data which is
irrelevant to the allocation request. But hugetlb_show_meminfo() still
shows hugetlb on all nodes, which is redundant and unnecessary.
Use show_mem_node_skip() to skip irrelevant nodes. And replace
hugetlb_show_meminfo() with hugetlb_show_meminfo_node(nid).
Patrick Wang [Tue, 5 Jul 2022 11:31:58 +0000 (19:31 +0800)]
mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free()
Kmemleak recently added a rbtree to store the objects allocted with
physical address. Those objects can't be freed with kmemleak_free().
According to the comments, percpu allocations are tracked by kmemleak
separately. Kmemleak_free() was used to avoid the unnecessary
tracking. If kmemleak_free() fails, those objects would be scanned by
kmemleak, which is unnecessary but shouldn't lead to other effects.
Use kmemleak_ignore_phys() instead of kmemleak_free() for those
objects.
Miaohe Lin [Mon, 4 Jul 2022 13:22:00 +0000 (21:22 +0800)]
mm/huge_memory: comment the subtly logic in __split_huge_pmd
It's dangerous and wrong to call page_folio(pmd_page(*pmd)) when pmd isn't
present. But the caller guarantees pmd is present when folio is set. So we
should be safe here. Add comment to make it clear.
Miaohe Lin [Mon, 4 Jul 2022 13:21:58 +0000 (21:21 +0800)]
mm/huge_memory: fix comment of page_deferred_list
The current comment is confusing because if global or memcg deferred list
in the second tail page is occupied by compound_head, why we still use
page[2].deferred_list here? I think it wants to say that Global or memcg
deferred list in the first tail page is occupied by compound_mapcount and
compound_pincount so we use the second tail page's deferred_list instead.
Miaohe Lin [Mon, 4 Jul 2022 13:21:57 +0000 (21:21 +0800)]
mm/huge_memory: minor cleanup for split_huge_pages_all
There is nothing to do if a zone doesn't have any pages managed by the
buddy allocator. So we should check managed_zone instead. Also if a thp
is found, there's no need to traverse the subpages again.
Miaohe Lin [Mon, 4 Jul 2022 13:21:56 +0000 (21:21 +0800)]
mm/huge_memory: try to free subpage in swapcache when possible
Subpages in swapcache won't be freed even if it is the last user of the
page until next time reclaim. It shouldn't hurt indeed, but we could try
to free these pages to save more memory for system.
Miaohe Lin [Mon, 4 Jul 2022 13:21:55 +0000 (21:21 +0800)]
mm/huge_memory: check pmd_present first in is_huge_zero_pmd
When pmd is non-present, pmd_pfn returns an insane value. So we should
check pmd_present first to avoid acquiring such insane value and also
avoid touching possible cold huge_zero_pfn cache line when pmd isn't
present.
Miaohe Lin [Mon, 4 Jul 2022 13:21:54 +0000 (21:21 +0800)]
mm/huge_memory: fix comment in zap_huge_pud
The comment about deposited pgtable is borrowed from zap_huge_pmd but
there's no deposited pgtable stuff for huge pud in zap_huge_pud. Remove
it to avoid confusion.
Miaohe Lin [Mon, 4 Jul 2022 13:21:51 +0000 (21:21 +0800)]
mm/huge_memory: rename mmun_start to haddr in remove_migration_pmd
mmun_start indicates mmu_notifier start address but there's no mmu_notifier
stuff in remove_migration_pmd. This will make it hard to get the meaning of
mmun_start. Rename it to haddr to avoid confusing readers and also imporve
readability.
Miaohe Lin [Mon, 4 Jul 2022 13:21:47 +0000 (21:21 +0800)]
mm/huge_memory: access vm_page_prot with READ_ONCE in remove_migration_pmd
vma->vm_page_prot is read lockless from the rmap_walk, it may be updated
concurrently. Using READ_ONCE to prevent the risk of reading intermediate
values.
Miaohe Lin [Mon, 4 Jul 2022 13:21:46 +0000 (21:21 +0800)]
mm/huge_memory: use flush_pmd_tlb_range in move_huge_pmd
Patch series "A few cleanup patches for huge_memory", v3.
This series contains a few cleaup patches to remove duplicated codes,
add/use helper functions, fix some obsolete comments and so on. More
details can be found in the respective changelogs.
This patch (of 16):
Arches with special requirements for evicting THP backing TLB entries can
implement flush_pmd_tlb_range. Otherwise also, it can help optimize TLB
flush in THP regime. Using flush_pmd_tlb_range to take advantage of this
in move_huge_pmd.
Now all the platforms enable ARCH_HAS_GET_PAGE_PROT. They define and
export own vm_get_page_prot() whether custom or standard
DECLARE_VM_GET_PAGE_PROT. Hence there is no need for default generic
fallback for vm_get_page_prot(). Just drop this fallback and also
ARCH_HAS_GET_PAGE_PROT mechanism.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.
mm/mmap: build protect protection_map[] with ARCH_HAS_VM_GET_PAGE_PROT
Now that protection_map[] has been moved inside those platforms that
enable ARCH_HAS_VM_GET_PAGE_PROT. Hence generic protection_map[] array
now can be protected with CONFIG_ARCH_HAS_VM_GET_PAGE_PROT intead of
__P000.
This moves protection_map[] inside the platform and makes it a static.
This also defines a helper function add_encrypt_protection_map() that can
update the protection_map[] array with pgprot_encrypted().
sparc/mm: move protection_map[] inside the platform
This moves protection_map[] inside the platform and while here, also
enable ARCH_HAS_VM_GET_PAGE_PROT on 32 bit platforms via
DECLARE_VM_GET_PAGE_PROT.
powerpc/mm: move protection_map[] inside the platform
This moves protection_map[] inside the platform and while here, also
enable ARCH_HAS_VM_GET_PAGE_PROT on 32 bit and nohash 64 (aka book3e/64)
platforms via DECLARE_VM_GET_PAGE_PROT.
This just converts the generic vm_get_page_prot() implementation into a
new macro i.e DECLARE_VM_GET_PAGE_PROT which later can be used across
platforms when enabling them with ARCH_HAS_VM_GET_PAGE_PROT. This does
not create any functional change.
mm/mmap: build protect protection_map[] with __P000
Patch series "mm/mmap: Drop __SXXX/__PXXX macros from across platforms",
v7.
__SXXX/__PXXX macros are unnecessary abstraction layer in creating the
generic protection_map[] array which is used for vm_get_page_prot(). This
abstraction layer can be avoided, if the platforms just define the array
protection_map[] for all possible vm_flags access permission combinations
and also export vm_get_page_prot() implementation.
This series drops __SXXX/__PXXX macros from across platforms in the tree.
First it build protects generic protection_map[] array with '#ifdef
__P000' and moves it inside platforms which enable
ARCH_HAS_VM_GET_PAGE_PROT. Later this build protects same array with
'#ifdef ARCH_HAS_VM_GET_PAGE_PROT' and moves inside remaining platforms
while enabling ARCH_HAS_VM_GET_PAGE_PROT. This adds a new macro
DECLARE_VM_GET_PAGE_PROT defining the current generic vm_get_page_prot(),
in order for it to be reused on platforms that do not require custom
implementation. Finally, ARCH_HAS_VM_GET_PAGE_PROT can just be dropped,
as all platforms now define and export vm_get_page_prot(), via looking up
a private and static protection_map[] array. protection_map[] data type
has been changed as 'static const' on all platforms that do not change it
during boot.
This patch (of 26):
Build protect generic protection_map[] array with __P000, so that it can
be moved inside all the platforms one after the other. Otherwise there
will be build failures during this process.
CONFIG_ARCH_HAS_VM_GET_PAGE_PROT cannot be used for this purpose as only
certain platforms enable this config now.
Linus Walleij [Thu, 30 Jun 2022 08:41:24 +0000 (10:41 +0200)]
mm: nommu: pass a pointer to virt_to_page()
Functions that work on a pointer to virtual memory such as virt_to_pfn()
and users of that function such as virt_to_page() are supposed to pass a
pointer to virtual memory, ideally a (void *) or other pointer. However
since many architectures implement virt_to_pfn() as a macro, this function
becomes polymorphic and accepts both a (unsigned long) and a (void *).
If we instead implement a proper virt_to_pfn(void *addr) function the
following happens (occurred on arch/arm):
mm/nommu.c: In function 'free_page_series':
mm/nommu.c:501:50: warning: passing argument 1 of 'virt_to_pfn'
makes pointer from integer without a cast [-Wint-conversion]
struct page *page = virt_to_page(from);
Linus Walleij [Thu, 30 Jun 2022 08:41:23 +0000 (10:41 +0200)]
mm: gup: pass a pointer to virt_to_page()
Functions that work on a pointer to virtual memory such as virt_to_pfn()
and users of that function such as virt_to_page() are supposed to pass a
pointer to virtual memory, ideally a (void *) or other pointer. However
since many architectures implement virt_to_pfn() as a macro, this function
becomes polymorphic and accepts both a (unsigned long) and a (void *).
If we instead implement a proper virt_to_pfn(void *addr) function the
following happens (occurred on arch/arm):
mm/gup.c: In function '__get_user_pages_locked':
mm/gup.c:1599:49: warning: passing argument 1 of 'virt_to_pfn'
makes pointer from integer without a cast [-Wint-conversion]
pages[i] = virt_to_page(start);
Linus Walleij [Thu, 30 Jun 2022 08:41:22 +0000 (10:41 +0200)]
mm: kfence: pass a pointer to virt_to_page()
Functions that work on a pointer to virtual memory such as virt_to_pfn()
and users of that function such as virt_to_page() are supposed to pass a
pointer to virtual memory, ideally a (void *) or other pointer. However
since many architectures implement virt_to_pfn() as a macro, this function
becomes polymorphic and accepts both a (unsigned long) and a (void *).
If we instead implement a proper virt_to_pfn(void *addr) function the
following happens (occurred on arch/arm):
mm/kfence/core.c:558:30: warning: passing argument 1
of 'virt_to_pfn' makes pointer from integer without a
cast [-Wint-conversion]
In one case we can refer to __kfence_pool directly (and that is a proper
(char *) pointer) and in the other call site we use an explicit cast.
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