Pull timekeeping updates from Andreas Hindborg:
- Expand the example section in the 'HrTimer' documentation.
- Mark the 'ClockSource' trait as unsafe to ensure valid values for
'ktime_get()'.
- Add 'Delta::from_nanos()'.
This is a back merge since the pull request has a newer base -- we will
avoid that in the future.
And, given it is a back merge, it happens to resolve the "subtle" conflict
around '--remap-path-{prefix,scope}' that I discussed in linux-next [1],
plus a few other common conflicts. The result matches what we did for
next-20260407.
The actual diffstat (i.e. using a temporary merge of upstream first) is:
rust/kernel/time.rs | 32 ++++-
rust/kernel/time/hrtimer.rs | 336 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 362 insertions(+), 6 deletions(-)
Link: https://lore.kernel.org/linux-next/CANiq72kdxB=W3_CV1U44oOK3SssztPo2wLDZt6LP94TEO+Kj4g@mail.gmail.com/ [1]
* tag 'rust-timekeeping-for-v7.1' of https://github.com/Rust-for-Linux/linux:
hrtimer: add usage examples to documentation
rust: time: make ClockSource unsafe trait
rust/time: Add Delta::from_nanos()
This adds the following commits from upstream:
53373d135579 dtc: Remove unused dts_version in dtc-lexer.l
caf7465c5d60 libfdt: fdt_check_full: Handle FDT_NOP when FDT_END is expected
5976c4a66098 libfdt: fdt_rw: Introduce fdt_downgrade_version()
5bb5bedd347d fdtdump: Return an error code on wrong tag value
68b960e299f7 fdtdump: Remove dtb version check
adba02caf554 dtc: Use a consistent type for basenamelen
8d15a63e84ff libfdt: Verify alignment of sub-blocks in dtb
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Currently checksyscalls.sh is unconditionally executed during each build.
Most of these executions are unnecessary.
Only run checksyscalls.sh if one of its inputs have changed.
This new logic does not work for the multiple invocations done for MIPS.
The effect is that checksyscalls.sh is still executed unconditionally.
However this is not worse than before.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260402-kbuild-missing-syscalls-v3-2-6641be1de2db@weissschuh.net
Signed-off-by: Nicolas Schier <nsc@kernel.org>
Currently you cannot filter out the crate-name argument
RUSTFLAGS_REMOVE_stem.o because the Rust filter-out invocation does not
include that particular argument. Since --crate-name is an argument that
can't be passed multiple times, this means that it's currently not
possible to override the crate name. Thus, remove the --crate-name
argument for drivers. This allows them to override the crate name using
the #![crate_name] annotation.
This affects symbol names, but has no effect on the filenames of object
files and other things generated by the build, as we always use --emit
with a fixed output filename.
The --crate-name argument is kept for the crates under rust/ for
simplicity and to avoid changing many of them by adding #![crate_name].
The rust analyzer script is updated to use rustc to obtain the crate
name of the driver crates, which picks up the right name whether it is
configured via #![crate_name] or not. For readability, the logic to
invoke 'rustc' is extracted to its own function.
Note that the crate name in the python script is not actually that
important - the only place where the name actually affects anything is
in the 'deps' array which specifies an index and name for each
dependency, and determines what that dependency is called in *this*
crate. (The same crate may be called different things in each
dependency.) Since driver crates are leaf crates, this doesn't apply and
the rustc invocation only affects the 'display_name' parameter.
Acked-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Jesung Yang <y.jems.n@gmail.com>
Acked-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260402-binder-crate-name-v4-1-ec3919b87909@google.com
[ Applied Python type hints. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
If 'readelf -n' encounters a note it does not recognize it emits a
warning. This for example happens when inspecting a compat vDSO for
which the main kernel toolchain was not used.
However the relevant build ID note is always readable, so the
warnings are pointless.
Hide the warnings to make it possible to extract build IDs for more
architectures in the future.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260331-kbuild-vdso-install-v2-2-606d0dc6beca@weissschuh.net
Signed-off-by: Nicolas Schier <nsc@kernel.org>
These sections are not used anymore and can be removed from vmlinux and
modules during linking.
Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Read kflagstab section for vmlinux and modules to determine whether
kernel symbols are GPL only.
This patch eliminates the need for fragmenting the ksymtab for infering
the value of GPL-only symbol flag, henceforth stop populating *_gpl
versions of the ksymtab and kcrctab in modpost.
Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This patch adds the ability to create entries for kernel symbol flag
bitsets in kflagstab. Modpost populates only the GPL-only flag for now.
Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This patch introduces a __kflagstab section to store symbol flags in a
dedicated data structure, similar to how CRCs are handled in the
__kcrctab.
The flags for a given symbol in __kflagstab will be located at the same
index as the symbol's entry in __ksymtab and its CRC in __kcrctab. This
design decouples the flags from the symbol table itself, allowing us to
maintain a single, sorted __ksymtab. As a result, the symbol search
remains an efficient, single lookup, regardless of the number of flags
we add in the future.
The motivation for this change comes from the Android kernel, which uses
an additional symbol flag to restrict the use of certain exported
symbols by unsigned modules, thereby enhancing kernel security. This
__kflagstab can be implemented as a bitmap to efficiently manage which
symbols are available for general use versus those restricted to signed
modules only.
This section will contain read-only data for values of kernel symbol
flags in the form of an 8-bit bitsets for each kernel symbol. Each bit
in the bitset represents a flag value defined by ksym_flags enumeration.
Petr Pavlu ran a small test to get a better understanding of the
different section sizes resulting from this patch series. He used
v6.17-rc6 together with the openSUSE x86_64 config [1], which is fairly
large. The resulting vmlinux.bin (no debuginfo) had an on-disk size of
58 MiB, and included 5937 + 6589 (GPL-only) exported symbols.
The following table summarizes his measurements and calculations
regarding the sizes of all sections related to exported symbols:
| HAVE_ARCH_PREL32_RELOCATIONS | !HAVE_ARCH_PREL32_RELOCATIONS
Section | Base [B] | Ext. [B] | Sep. [B] | Base [B] | Ext. [B] | Sep. [B]
----------------------------------------------------------------------------------------
__ksymtab | 71244 | 200416 | 150312 | 142488 | 400832 | 300624
__ksymtab_gpl | 79068 | NA | NA | 158136 | NA | NA
__kcrctab | 23748 | 50104 | 50104 | 23748 | 50104 | 50104
__kcrctab_gpl | 26356 | NA | NA | 26356 | NA | NA
__ksymtab_strings | 253628 | 253628 | 253628 | 253628 | 253628 | 253628
__kflagstab | NA | NA | 12526 | NA | NA | 12526
----------------------------------------------------------------------------------------
Total | 454044 | 504148 | 466570 | 604356 | 704564 | 616882
Increase to base [%] | NA | 11.0 | 2.8 | NA | 16.6 | 2.1
The column "HAVE_ARCH_PREL32_RELOCATIONS -> Base" contains the measured
numbers. The rest of the values are calculated. The "Ext." column
represents an alternative approach of extending __ksymtab to include a
bitset of symbol flags, and the "Sep." column represents the approach of
having a separate __kflagstab. With HAVE_ARCH_PREL32_RELOCATIONS, each
kernel_symbol is 12 B in size and is extended to 16 B. With
!HAVE_ARCH_PREL32_RELOCATIONS, it is 24 B, extended to 32 B. Note that
this does not include the metadata needed to relocate __ksymtab*, which
is freed after the initial processing.
Adding __kflagstab as a separate section has a negligible impact, as
expected. When extending __ksymtab (kernel_symbol) instead, the worst
case with !HAVE_ARCH_PREL32_RELOCATIONS increases the export data size
by 16.6%. Note that the larger increase in size for the latter approach
is due to 4-byte alignment of kernel_symbol data structure, instead of
1-byte alignment for the flags bitset in __kflagstab in the former
approach.
Based on the above, it was concluded that introducing __kflagstab makes
sense, as the added complexity is minimal over extending kernel_symbol,
and there is overall simplification of symbol finding logic in the
module loader.
Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
[Sami: Updated commit message to include details from the cover letter.]
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This reverts commit 8545d9bc4b.
Unbeknownst to me, and unremarked upon by the checkpatch maintainer, this
same problem was also solved in the mm tree. Fixing it once is enough, so
this one comes out.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Thomas Gleixner
Miguel Ojeda
Rob Herring (Arm)
Masahiro Yamada
Thomas Weißschuh
Alexei Starovoitov
Alice Ryhl
Siddharth Nayyar
Jonathan Corbet