Pull Kbuild updates from Masahiro Yamada:
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
exports a symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
genksyms: Fix enum consts from a reference affecting new values
arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
efi/libstub: use 'targets' instead of extra-y in Makefile
module: make __mod_device_table__* symbols static
scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
scripts/misc-check: check missing #include <linux/export.h> when W=1
scripts/misc-check: add double-quotes to satisfy shellcheck
kbuild: move W=1 check for scripts/misc-check to top-level Makefile
scripts/tags.sh: allow to use alternative ctags implementation
kconfig: introduce menu type enum
docs: symbol-namespaces: fix reST warning with literal block
kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
docs/core-api/symbol-namespaces: drop table of contents and section numbering
modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
kbuild: move kbuild syntax processing to scripts/Makefile.build
Makefile: remove dependency on archscripts for header installation
Documentation/kbuild: Add new gendwarfksyms kABI rules
Documentation/kbuild: Drop section numbers
...
Pull module updates from Petr Pavlu:
- Make .static_call_sites in modules read-only after init
The .static_call_sites sections in modules have been made read-only
after init to avoid any (non-)accidental modifications, similarly to
how they are read-only after init in vmlinux
- The rest are minor cleanups
* tag 'modules-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
module: Remove outdated comment about text_size
module: Make .static_call_sites read-only after init
module: Add a separate function to mark sections as read-only after init
module: Constify parameters of module_enforce_rwx_sections()
Pull hotfixes from Andrew Morton:
"22 hotfixes.
13 are cc:stable and the remainder address post-6.14 issues or aren't
considered necessary for -stable kernels. 19 are for MM"
* tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
mailmap: add Jarkko's employer email address
mm: fix copy_vma() error handling for hugetlb mappings
memcg: always call cond_resched() after fn()
mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios
mm: vmalloc: only zero-init on vrealloc shrink
mm: vmalloc: actually use the in-place vrealloc region
alloc_tag: allocate percpu counters for module tags dynamically
module: release codetag section when module load fails
mm/cma: make detection of highmem_start more robust
MAINTAINERS: add mm memory policy section
MAINTAINERS: add mm ksm section
kasan: avoid sleepable page allocation from atomic context
highmem: add folio_test_partial_kmap()
MAINTAINERS: add hung-task detector section
taskstats: fix struct taskstats breaks backward compatibility since version 15
mm/truncate: fix out-of-bounds when doing a right-aligned split
MAINTAINERS: add mm reclaim section
MAINTAINERS: update page allocator section
mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y
mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled
...
Sean noted that scripts/Makefile.lib:name-fix-token rule will mangle
the module name with s/-/_/g.
Since this happens late in the build, only the kernel needs to bother
with this, the modpost tool still sees the original name.
Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Instead of only accepting "module:${name}", extend it with a comma
separated list of module names and add tail glob support.
That is, something like: "module:foo-*,bar" is now possible.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Designate the "module:${modname}" symbol namespace to mean: 'only
export to the named module'.
Notably, explicit imports of anything in the "module:" space is
forbidden.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Section .static_call_sites holds data structures that need to be sorted and
processed only at module load time. This initial processing happens in
static_call_add_module(), which is invoked as a callback to the
MODULE_STATE_COMING notification from prepare_coming_module().
The section is never modified afterwards. Make it therefore read-only after
module initialization to avoid any (non-)accidental modifications.
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20250306131430.7016-4-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
With CONFIG_GENDWARFKSYMS, __gendwarfksyms_ptr variables are
added to the kernel in EXPORT_SYMBOL() to ensure DWARF type
information is available for exported symbols in the TUs where
they're actually exported. These symbols are dropped when linking
vmlinux, but dangling references to them remain in DWARF.
With CONFIG_DEBUG_INFO_BTF enabled on X86, pahole versions after
commit 47dcb534e253 ("btf_encoder: Stop indexing symbols for
VARs") and before commit 9810758003ce ("btf_encoder: Verify 0
address DWARF variables are in ELF section") place these symbols
in the .data..percpu section, which results in an "Invalid
offset" error in btf_datasec_check_meta() during boot, as all
the variables are at zero offset and have non-zero size. If
CONFIG_DEBUG_INFO_BTF_MODULES is enabled, this also results in a
failure to load modules with:
failed to validate module [$module] BTF: -22
As the issue occurs in pahole v1.28 and the fix was merged
after v1.29 was released, require pahole <v1.28 or >v1.29 when
GENDWARFKSYMS is enabled with DEBUG_INFO_BTF on X86.
Reported-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull ring-buffer updates from Steven Rostedt:
- Restructure the persistent memory to have a "scratch" area
Instead of hard coding the KASLR offset in the persistent memory by
the ring buffer, push that work up to the callers of the persistent
memory as they are the ones that need this information. The offsets
and such is not important to the ring buffer logic and it should not
be part of that.
A scratch pad is now created when the caller allocates a ring buffer
from persistent memory by stating how much memory it needs to save.
- Allow where modules are loaded to be saved in the new scratch pad
Save the addresses of modules when they are loaded into the
persistent memory scratch pad.
- A new module_for_each_mod() helper function was created
With the acknowledgement of the module maintainers a new module
helper function was created to iterate over all the currently loaded
modules. This has a callback to be called for each module. This is
needed for when tracing is started in the persistent buffer and the
currently loaded modules need to be saved in the scratch area.
- Expose the last boot information where the kernel and modules were
loaded
The last_boot_info file is updated to print out the addresses of
where the kernel "_text" location was loaded from a previous boot, as
well as where the modules are loaded. If the buffer is recording the
current boot, it only prints "# Current" so that it does not expose
the KASLR offset of the currently running kernel.
- Allow the persistent ring buffer to be released (freed)
To have this in production environments, where the kernel command
line can not be changed easily, the ring buffer needs to be freed
when it is not going to be used. The memory for the buffer will
always be allocated at boot up, but if the system isn't going to
enable tracing, the memory needs to be freed. Allow it to be freed
and added back to the kernel memory pool.
- Allow stack traces to print the function names in the persistent
buffer
Now that the modules are saved in the persistent ring buffer, if the
same modules are loaded, the printing of the function names will
examine the saved modules. If the module is found in the scratch area
and is also loaded, then it will do the offset shift and use kallsyms
to display the function name. If the address is not found, it simply
displays the address from the previous boot in hex.
* tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Use _text and the kernel offset in last_boot_info
tracing: Show last module text symbols in the stacktrace
ring-buffer: Remove the unused variable bmeta
tracing: Skip update_last_data() if cleared and remove active check for save_mod()
tracing: Initialize scratch_size to zero to prevent UB
tracing: Fix a compilation error without CONFIG_MODULES
tracing: Freeable reserved ring buffer
mm/memblock: Add reserved memory release function
tracing: Update modules to persistent instances when loaded
tracing: Show module names and addresses of last boot
tracing: Have persistent trace instances save module addresses
module: Add module_for_each_mod() function
tracing: Have persistent trace instances save KASLR offset
ring-buffer: Add ring_buffer_meta_scratch()
ring-buffer: Add buffer meta data for persistent ring buffer
ring-buffer: Use kaslr address instead of text delta
ring-buffer: Fix bytes_dropped calculation issue
Pull modules updates from Petr Pavlu:
- Use RCU instead of RCU-sched
The mix of rcu_read_lock(), rcu_read_lock_sched() and
preempt_disable() in the module code and its users has
been replaced with just rcu_read_lock()
- The rest of changes are smaller fixes and updates
* tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (32 commits)
MAINTAINERS: Update the MODULE SUPPORT section
module: Remove unnecessary size argument when calling strscpy()
module: Replace deprecated strncpy() with strscpy()
params: Annotate struct module_param_attrs with __counted_by()
bug: Use RCU instead RCU-sched to protect module_bug_list.
static_call: Use RCU in all users of __module_text_address().
kprobes: Use RCU in all users of __module_text_address().
bpf: Use RCU in all users of __module_text_address().
jump_label: Use RCU in all users of __module_text_address().
jump_label: Use RCU in all users of __module_address().
x86: Use RCU in all users of __module_address().
cfi: Use RCU while invoking __module_address().
powerpc/ftrace: Use RCU in all users of __module_text_address().
LoongArch: ftrace: Use RCU in all users of __module_text_address().
LoongArch/orc: Use RCU in all users of __module_address().
arm64: module: Use RCU in all users of __module_text_address().
ARM: module: Use RCU in all users of __module_text_address().
module: Use RCU in all users of __module_text_address().
module: Use RCU in all users of __module_address().
module: Use RCU in search_module_extables().
...
search_module_extables() returns an exception_table_entry belonging to a
module. The lookup via __module_address() can be performed with RCU
protection.
The returned exception_table_entry remains valid because the passed
address usually belongs to a module that is currently executed. So the
module can not be removed because "something else" holds a reference to
it, ensuring that it can not be removed.
Exceptions here are:
- kprobe, acquires a reference on the module beforehand
- MCE, invokes the function from within a timer and the RCU lifetime
guarantees (of the timer) are sufficient.
Therefore it is safe to return the exception_table_entry outside the RCU
section which provided the module.
Use RCU for the lookup in search_module_extables() and update the
comment.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-14-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
mod_find() uses either the modules list to find a module or a tree
lookup (CONFIG_MODULES_TREE_LOOKUP). The list and the tree can both be
iterated under RCU assumption (as well as RCU-sched).
Remove module_assert_mutex_or_preempt() from __module_address() and
entirely since __module_address() is the last user.
Update comments.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-13-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
module_assert_mutex_or_preempt() is not needed in find_symbol(). The
function checks for RCU-sched or the module_mutex to be acquired. The
list_for_each_entry_rcu() below does the same check.
Remove module_assert_mutex_or_preempt() from try_add_tainted_module().
Use RCU protection to invoke find_symbol() and update callers.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-11-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Linus Torvalds
Suren Baghdasaryan
Peter Zijlstra
David Wang
Valentin Schneider
Petr Pavlu
Sami Tolvanen
Steven Rostedt
Thorsten Blum
Sebastian Andrzej Siewior