PAGEMAP_SCAN already reports PAGE_IS_WRITTEN from the inverted uffd PTE
bit, targeting the UFFDIO_WRITEPROTECT workflow. UFFDIO_RWPROTECT reuses
the same PTE bit as a marker for read-write protection, but "has been
written" and "has been accessed" are distinct semantic signals — they
happen to share one PTE bit today only because the two implementations
share infrastructure.
Give RWP its own pagemap category so the UAPI does not conflate them:
PAGE_IS_WRITTEN reported on VM_UFFD_WP VMAs, !pte_uffd(pte)
PAGE_IS_ACCESSED reported on VM_UFFD_RWP VMAs, !pte_uffd(pte)
Both still read the same PTE bit today, but each is scoped to the VMA
whose registered mode makes the bit meaningful. If a future
implementation moves RWP to a separate PTE bit, only PAGE_IS_ACCESSED
switches over.
This is a UAPI narrowing. Outside VM_UFFD_WP VMAs the uffd bit is always
clear, so PAGEMAP_SCAN used to flag PAGE_IS_WRITTEN on every present PTE
there — a meaningless duplicate of PAGE_IS_PRESENT. Now PAGE_IS_WRITTEN
fires only inside VM_UFFD_WP VMAs.
pagemap_hugetlb_category() now takes the vma like its PTE/PMD peers.
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Kiryl Shutsemau <[email protected]>
Assisted-by: Claude:claude-opus-4-6
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: James Houghton <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
On Ubuntu 23.04, on a clean git tree, the selftests/mm build fails due 10
or 20 missing items, all of which are found in fs.h, which is created via
"make headers". However, as per [1], the idea is to stop requiring "make
headers", and instead, take a snapshot of the files and check them in.
Here are a few of the build errors:
vm_util.c:34:21: error: variable has incomplete type 'struct pm_scan_arg'
struct pm_scan_arg arg;
...
vm_util.c:45:28: error: use of undeclared identifier 'PAGE_IS_WPALLOWED'
...
vm_util.c:55:21: error: variable has incomplete type 'struct page_region'
...
vm_util.c:105:20: error: use of undeclared identifier 'PAGE_IS_SOFT_DIRTY'
To fix this, add fs.h, taken from a snapshot of ./usr/include/linux/fs.h
after running "make headers".
[1] commit e076eaca59 ("selftests: break the dependency upon local
header files")
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jeff Xu <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
It is mostly used only to generate string tables, not to build perf, so
move it to the tools/perf/trace/beauty/include/ hierarchy, that is used
just for scraping.
The only case where it was being used to build was in
tools/perf/trace/beauty/sync_file_range.c, because some older systems
doesn't have the SYNC_FILE_RANGE_WRITE_AND_WAIT define, just use the
system's linux/fs.h header instead, defining it if not available.
This is a something that should've have happened, as happened with the
linux/socket.h scrapper, do it now as Ian suggested while doing an
audit/refactor session in the headers used by perf.
No other tools/ living code uses it, just <linux/fs.h> coming from
either 'make install_headers' or from the system /usr/include/
directory.
Suggested-by: Ian Rogers <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/lkml/CAP-5=fWZVrpRufO4w-S4EcSi9STXcTAN2ERLwTSN7yrSSA-otQ@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The PAGEMAP_SCAN ioctl returns information regarding page table entries.
It is more efficient compared to reading pagemap files. CRIU can start to
utilize this ioctl, but it needs info about soft-dirty bits to track
memory changes.
We are aware of a new method for tracking memory changes implemented in
the PAGEMAP_SCAN ioctl. For CRIU, the primary advantage of this method is
its usability by unprivileged users. However, it is not feasible to
transparently replace the soft-dirty tracker with the new one. The main
problem here is userfault descriptors that have to be preserved between
pre-dump iterations. It means criu continues supporting the soft-dirty
method to avoid breakage for current users. The new method will be
implemented as a separate feature.
[[email protected]: update tools/include/uapi/linux/fs.h]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrei Vagin <[email protected]>
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Cc: Michał Mirosław <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].
This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)
@@
identifier S, member, array;
type T1, T2;
@@
struct S {
...
T1 member;
T2 array[
- 0
];
};
-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:
../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
strcpy(de3->name, ".");
^
Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%[email protected]/
Acked-by: Dan Williams <[email protected]> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <[email protected]>
To pick the change in:
7957d93bf3 ("block: add ioctl to read the disk sequence number")
It adds a new ioctl, but we are still not using that to generate tables
for 'perf trace', so no changes in tooling.
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
Cc: Jens Axboe <[email protected]>
Cc: Matteo Croce <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
To pick the trivial change in:
63c8af5687 ("block: uapi: fix comment about block device ioctl")
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
Cc: Damien Le Moal <[email protected]>
Cc: Jens Axboe <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
To pick the changes from:
b383a73f2b ("fs/ext4: Introduce DAX inode flag")
And silence this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
It causes various beautifiers for things like fspick, fsmount, etc (see
below) to get rebuilt, but this specific change doesn't make 'perf
trace' be capable of decoding anything new, as we still don't decode
what comes from ioctls, just its cmds.
Details about the update:
$ cp include/uapi/linux/fs.h tools/include/uapi/linux/fs.h
$ git diff
diff --git a/tools/include/uapi/linux/fs.h b/tools/include/uapi/linux/fs.h
index 379a612f8f1d..f44eb0a04afd 100644
--- a/tools/include/uapi/linux/fs.h
+++ b/tools/include/uapi/linux/fs.h
@@ -262,6 +262,7 @@ struct fsxattr {
#define FS_EA_INODE_FL 0x00200000 /* Inode used for large EA */
#define FS_EOFBLOCKS_FL 0x00400000 /* Reserved for ext4 */
#define FS_NOCOW_FL 0x00800000 /* Do not cow file */
+#define FS_DAX_FL 0x02000000 /* Inode is DAX */
#define FS_INLINE_DATA_FL 0x10000000 /* Reserved for ext4 */
#define FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */
#define FS_CASEFOLD_FL 0x40000000 /* Folder is case insensitive */
$ m
make: Entering directory '/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j8' parallel build
INSTALL GTK UI
CC /tmp/build/perf/builtin-trace.o
DESCEND plugins
CC /tmp/build/perf/trace/beauty/fsmount.o
CC /tmp/build/perf/trace/beauty/fspick.o
CC /tmp/build/perf/trace/beauty/mount_flags.o
CC /tmp/build/perf/trace/beauty/move_mount.o
CC /tmp/build/perf/trace/beauty/renameat.o
CC /tmp/build/perf/trace/beauty/sync_file_range.o
INSTALL trace_plugins
LD /tmp/build/perf/trace/beauty/perf-in.o
LD /tmp/build/perf/perf-in.o
LINK /tmp/build/perf/perf
<SNIP>
Cc: Adrian Hunter <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
To pick the changes from:
78a1b96bcf ("fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctl")
23c688b540 ("fscrypt: allow unprivileged users to add/remove keys for v2 policies")
5dae460c22 ("fscrypt: v2 encryption policy support")
5a7e29924d ("fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctl")
b1c0ec3599 ("fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl")
22d94f493b ("fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl")
3b6df59bc4 ("fscrypt: use FSCRYPT_* definitions, not FS_*")
2336d0deb2 ("fscrypt: use FSCRYPT_ prefix for uapi constants")
7af0ab0d3a ("fs, fscrypt: move uapi definitions to new header <linux/fscrypt.h>")
That don't trigger any changes in tooling, as it so far is used only
for:
$ grep -l 'fs\.h' tools/perf/trace/beauty/*.sh | xargs grep regex=
tools/perf/trace/beauty/rename_flags.sh:regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+RENAME_([[:alnum:]_]+)[[:space:]]+\(1[[:space:]]*<<[[:space:]]*([[:xdigit:]]+)[[:space:]]*\)[[:space:]]*.*'
tools/perf/trace/beauty/sync_file_range.sh:regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+SYNC_FILE_RANGE_([[:alnum:]_]+)[[:space:]]+([[:xdigit:]]+)[[:space:]]*.*'
tools/perf/trace/beauty/usbdevfs_ioctl.sh:regex="^#[[:space:]]*define[[:space:]]+USBDEVFS_(\w+)(\(\w+\))?[[:space:]]+_IO[CWR]{0,2}\([[:space:]]*(_IOC_\w+,[[:space:]]*)?'U'[[:space:]]*,[[:space:]]*([[:digit:]]+).*"
tools/perf/trace/beauty/usbdevfs_ioctl.sh:regex="^#[[:space:]]*define[[:space:]]+USBDEVFS_(\w+)[[:space:]]+_IO[WR]{0,2}\([[:space:]]*'U'[[:space:]]*,[[:space:]]*([[:digit:]]+).*"
$
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
Cc: Adrian Hunter <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
In preparation for including the casefold feature within f2fs, elevate
the EXT4_CASEFOLD_FL flag to FS_CASEFOLD_FL.
Signed-off-by: Daniel Rosenberg <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
To pick up the changes in:
c553ea4fdf ("fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback")
That should be used to beautify the 'sync_file_range' syscall 'flags'
arg.
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
Cc: Adrian Hunter <[email protected]>
Cc: Amir Goldstein <[email protected]>
Cc: Brendan Gregg <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luis Cláudio Gonçalves <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
To get the changes in:
e262e32d6b ("vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled")
That made the mount flags string table generator to switch to using
mount.h instead.
This silences the following perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
Cc: Adrian Hunter <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Luis Cláudio Gonçalves <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
