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Liam R. Howlett f8d112a4e6 mm/mmap: avoid zeroing vma tree in mmap_region()
Instead of zeroing the vma tree and then overwriting the area, let the
area be overwritten and then clean up the gathered vmas using
vms_complete_munmap_vmas().

To ensure locking is downgraded correctly, the mm is set regardless of
MAP_FIXED or not (NULL vma).

If a driver is mapping over an existing vma, then clear the ptes before
the call_mmap() invocation.  This is done using the vms_clean_up_area()
helper.  If there is a close vm_ops, that must also be called to ensure
any cleanup is done before mapping over the area.  This also means that
calling open has been added to the abort of an unmap operation, for now.

Since vm_ops->open() and vm_ops->close() are not always undo each other
(state cleanup may exist in ->close() that is lost forever), the code
cannot be left in this way, but that change has been isolated to another
commit to make this point very obvious for traceability.

Temporarily keep track of the number of pages that will be removed and
reduce the charged amount.

This also drops the validate_mm() call in the vma_expand() function.  It
is necessary to drop the validate as it would fail since the mm map_count
would be incorrect during a vma expansion, prior to the cleanup from
vms_complete_munmap_vmas().

Clean up the error handing of the vms_gather_munmap_vmas() by calling the
verification within the function.

Link: https://lkml.kernel.org/r/20240830040101.822209-15-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:51 -07:00
arch x86: remove PG_uncached 2024-09-03 21:15:46 -07:00
block block: fix detection of unsupported WRITE SAME in blkdev_issue_write_zeroes 2024-08-28 08:49:25 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto crypto: testmgr - generate power-of-2 lengths more often 2024-07-13 11:50:28 +12:00
Documentation Documentation/cgroup-v2: clarify that zswap.writeback is ignored if zswap is disabled 2024-09-03 21:15:48 -07:00
drivers zsmalloc: use all available 24 bits of page_type 2024-09-03 21:15:43 -07:00
fs x86: remove PG_uncached 2024-09-03 21:15:46 -07:00
include mm: store zero pages to be swapped out in a bitmap 2024-09-03 21:15:47 -07:00
init mm: fix typo in Kconfig 2024-09-01 20:25:45 -07:00
io_uring io_uring/kbuf: return correct iovec count from classic buffer peek 2024-08-30 10:45:54 -06:00
ipc sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kernel mm: support only one page_type per page 2024-09-03 21:15:43 -07:00
lib printf: remove %pGt support 2024-09-03 21:15:42 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/mmap: avoid zeroing vma tree in mmap_region() 2024-09-03 21:15:51 -07:00
net Including fixes from bluetooth, wireless and netfilter. 2024-08-30 06:14:39 +12:00
rust Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
samples kmemleak-test: add percpu leak 2024-09-01 20:25:50 -07:00
scripts kasan: simplify and clarify Makefile 2024-09-03 21:15:35 -07:00
security Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging 2024-09-01 09:18:48 +12:00
sound sound fixes for 6.11-rc6 2024-08-28 06:24:22 +12:00
tools selftests: test_zswap: add test for hierarchical zswap.writeback 2024-09-03 21:15:47 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) 2024-08-14 12:28:24 -04:00
.clang-format Docs: Move clang-format from process/ to dev-tools/ 2024-06-26 16:36:00 -06:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: add script and target to generate pacman package 2024-07-22 01:24:22 +09:00
.mailmap ARM: SoC fixes for 6.11, part 2 2024-09-01 06:42:13 +12:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS tracing: Update of MAINTAINERS and CREDITS file 2024-07-18 14:08:42 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS tools: add skeleton code for userland testing of VMA logic 2024-09-01 20:25:55 -07:00
Makefile Linux 6.11-rc6 2024-09-01 19:46:02 +12:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.