wireguard-linux/scripts/Makefile, branch davem/net-next

tracing: Add a tracepoint verification check at build time

2025-10-24T20:43:14Z

If a tracepoint is defined via DECLARE_TRACE() or TRACE_EVENT() but never called (via the trace_() function), its metadata is still around in memory and not discarded. When created via TRACE_EVENT() the situation is worse because the TRACE_EVENT() creates metadata that can be around 5k per trace event. Having unused trace events causes several thousand of wasted bytes. Add a verifier that injects a string of the name of the tracepoint it calls that is added to the discarded section "__tracepoint_check". For every builtin tracepoint, its name (which is saved in the in-memory section "__tracepoint_strings") will have its name also in the "__tracepoint_check" section if it is used. Add a new program that is run on build called tracepoint-update. This is executed on the vmlinux.o before the __tracepoint_check section is discarded (the section is discarded before vmlinux is created). This program will create an array of each string in the __tracepoint_check section and then sort it. Then it will walk the strings in the __tracepoint_strings section and do a binary search to check if its name is in the __tracepoint_check section. If it is not, then it is unused and a warning is printed. Note, this currently only handles tracepoints that are builtin and not in modules. Enabling this currently with a given config produces: warning: tracepoint 'sched_move_numa' is unused. warning: tracepoint 'sched_stick_numa' is unused. warning: tracepoint 'sched_swap_numa' is unused. warning: tracepoint 'pelt_hw_tp' is unused. warning: tracepoint 'pelt_irq_tp' is unused. warning: tracepoint 'rcu_preempt_task' is unused. warning: tracepoint 'rcu_unlock_preempted_task' is unused. warning: tracepoint 'xdp_bulk_tx' is unused. warning: tracepoint 'xdp_redirect_map' is unused. warning: tracepoint 'xdp_redirect_map_err' is unused. warning: tracepoint 'vma_mas_szero' is unused. warning: tracepoint 'vma_store' is unused. warning: tracepoint 'hugepage_set_pmd' is unused. warning: tracepoint 'hugepage_set_pud' is unused. warning: tracepoint 'hugepage_update_pmd' is unused. warning: tracepoint 'hugepage_update_pud' is unused. warning: tracepoint 'block_rq_remap' is unused. warning: tracepoint 'xhci_dbc_handle_event' is unused. warning: tracepoint 'xhci_dbc_handle_transfer' is unused. warning: tracepoint 'xhci_dbc_gadget_ep_queue' is unused. warning: tracepoint 'xhci_dbc_alloc_request' is unused. warning: tracepoint 'xhci_dbc_free_request' is unused. warning: tracepoint 'xhci_dbc_queue_request' is unused. warning: tracepoint 'xhci_dbc_giveback_request' is unused. warning: tracepoint 'tcp_ao_wrong_maclen' is unused. warning: tracepoint 'tcp_ao_mismatch' is unused. warning: tracepoint 'tcp_ao_key_not_found' is unused. warning: tracepoint 'tcp_ao_rnext_request' is unused. warning: tracepoint 'tcp_ao_synack_no_key' is unused. warning: tracepoint 'tcp_ao_snd_sne_update' is unused. warning: tracepoint 'tcp_ao_rcv_sne_update' is unused. Some of the above is totally unused but others are not used due to their "trace_" functions being inside configs, in which case, the defined tracepoints should also be inside those same configs. Others are architecture specific but defined in generic code, where they should either be moved to the architecture or be surrounded by #ifdef for the architectures they are for. This tool could be updated to process modules in the future. I'd like to thank Mathieu Desnoyers for suggesting using strings instead of pointers, as using pointers in vmlinux.o required handling relocations and it required implementing almost a full feature linker to do so. To enable this check, run the build with: make UT=1 Note, when all the existing unused tracepoints are removed from the build, the "UT=1" will be removed and this will always be enabled when tracepoints are configured to warn on any new tracepoints. The reason this isn't always enabled now is because it will introduce a lot of warnings for the current unused tracepoints, and all bisects would end at this commit for those warnings. Link: https://lore.kernel.org/all/20250528114549.4d8a5e03@gandalf.local.home/ Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Arnd Bergmann Cc: Masahiro Yamada Cc: Nathan Chancellor Cc: Nicolas Schier Cc: Nick Desaulniers Cc: Catalin Marinas Cc: Linus Torvalds Cc: Randy Dunlap Cc: Stephen Rothwell Link: https://lore.kernel.org/20251022004452.920728129@kernel.org Suggested-by: Mathieu Desnoyers # for using strings instead of pointers Signed-off-by: Steven Rostedt (Google)

sorttable: Move ELF parsing into scripts/elf-parse.[ch]

2025-10-24T20:43:14Z

In order to share the elf parsing that is in sorttable.c so that other programs could use the same code, move it into elf-parse.c and elf-parse.h. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Arnd Bergmann Cc: Masahiro Yamada Cc: Nathan Chancellor Cc: Nicolas Schier Cc: Nick Desaulniers Cc: Catalin Marinas Cc: Linus Torvalds Cc: Randy Dunlap Cc: Stephen Rothwell Link: https://lore.kernel.org/20251022004452.752298788@kernel.org Signed-off-by: Steven Rostedt (Google)

Merge tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2025-01-31T20:07:07Z

Pull Kbuild updates from Masahiro Yamada: - Support multiple hook locations for maint scripts of Debian package - Remove 'cpio' from the build tool requirement - Introduce gendwarfksyms tool, which computes CRCs for export symbols based on the DWARF information - Support CONFIG_MODVERSIONS for Rust - Resolve all conflicts in the genksyms parser - Fix several syntax errors in genksyms * tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits) kbuild: fix Clang LTO with CONFIG_OBJTOOL=n kbuild: Strip runtime const RELA sections correctly kconfig: fix memory leak in sym_warn_unmet_dep() kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST genksyms: fix syntax error for attribute before init-declarator genksyms: fix syntax error for builtin (u)int*x*_t types genksyms: fix syntax error for attribute after 'union' genksyms: fix syntax error for attribute after 'struct' genksyms: fix syntax error for attribute after abstact_declarator genksyms: fix syntax error for attribute before nested_declarator genksyms: fix syntax error for attribute before abstract_declarator genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier genksyms: record attributes consistently for init-declarator genksyms: restrict direct-declarator to take one parameter-type-list genksyms: restrict direct-abstract-declarator to take one parameter-type-list genksyms: remove Makefile hack genksyms: fix last 3 shift/reduce conflicts genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts genksyms: reduce type_qualifier directly to decl_specifier genksyms: rename cvar_qualifier to type_qualifier ...

kbuild: Add gendwarfksyms as an alternative to genksyms

2025-01-10T16:25:26Z

When MODVERSIONS is enabled, allow selecting gendwarfksyms as the implementation, but default to genksyms. Signed-off-by: Sami Tolvanen Signed-off-by: Masahiro Yamada

tools: Add gendwarfksyms

2025-01-10T16:25:25Z

Add a basic DWARF parser, which uses libdw to traverse the debugging information in an object file and looks for functions and variables. In follow-up patches, this will be expanded to produce symbol versions for CONFIG_MODVERSIONS from DWARF. Signed-off-by: Sami Tolvanen Reviewed-by: Petr Pavlu Signed-off-by: Masahiro Yamada

lib: packing: add pack_fields() and unpack_fields()

2024-12-12T04:13:00Z

This is new API which caters to the following requirements: - Pack or unpack a large number of fields to/from a buffer with a small code footprint. The current alternative is to open-code a large number of calls to pack() and unpack(), or to use packing() to reduce that number to half. But packing() is not const-correct. - Use unpacked numbers stored in variables smaller than u64. This reduces the rodata footprint of the stored field arrays. - Perform error checking at compile time, rather than runtime, and return void from the API functions. Because the C preprocessor can't generate variable length code (loops), this is a bit tricky to do with macros. To handle this, implement macros which sanity check the packed field definitions based on their size. Finally, a single macro with a chain of __builtin_choose_expr() is used to select the appropriate macros. We enforce the use of ascending or descending order to avoid O(N^2) scaling when checking for overlap. Note that the macros are written with care to ensure that the compilers can correctly evaluate the resulting code at compile time. In particular, care was taken with avoiding too many nested statement expressions. Nested statement expressions trip up some compilers, especially when passing down variables created in previous statement expressions. There are two key design choices intended to keep the overall macro code size small. First, the definition of each CHECK_PACKED_FIELDS_N macro is implemented recursively, by calling the N-1 macro. This avoids needing the code to repeat multiple times. Second, the CHECK_PACKED_FIELD macro enforces that the fields in the array are sorted in order. This allows checking for overlap only with neighboring fields, rather than the general overlap case where each field would need to be checked against other fields. The overlap checks use the first two fields to determine the order of the remaining fields, thus allowing either ascending or descending order. This enables drivers the flexibility to keep the fields ordered in which ever order most naturally fits their hardware design and its associated documentation. The CHECK_PACKED_FIELDS macro is directly called from within pack_fields and unpack_fields, ensuring that all drivers using the API receive the benefits of the compile-time checks. Users do not need to directly call any of the macros directly. The CHECK_PACKED_FIELDS and its helper macros CHECK_PACKED_FIELDS_(0..50) are generated using a simple C program in scripts/gen_packed_field_checks.c This program can be compiled on demand and executed to generate the macro code in include/linux/packing.h. This will aid in the event that a driver needs more than 50 fields. The generator can be updated with a new size, and used to update the packing.h header file. In practice, the ice driver will need to support 27 fields, and the sja1105 driver will need to support 0 fields. This on-demand generation avoids the need to modify Kbuild. We do not anticipate the maximum number of fields to grow very often. - Reduced rodata footprint for the storage of the packed field arrays. To that end, we have struct packed_field_u8 and packed_field_u16, which define the fields with the associated type. More can be added as needed (unlikely for now). On these types, the same generic pack_fields() and unpack_fields() API can be used, thanks to the new C11 _Generic() selection feature, which can call pack_fields_u8() or pack_fields_16(), depending on the type of the "fields" array - a simplistic form of polymorphism. It is evaluated at compile time which function will actually be called. Over time, packing() is expected to be completely replaced either with pack() or with pack_fields(). Signed-off-by: Vladimir Oltean Co-developed-by: Jacob Keller Signed-off-by: Jacob Keller Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20241210-packing-pack-fields-and-ice-implementation-v10-3-ee56a47479ac@intel.com Signed-off-by: Jakub Kicinski

scripts: add boot policy generation program

2024-08-20T18:03:39Z

Enables an IPE policy to be enforced from kernel start, enabling access control based on trust from kernel startup. This is accomplished by transforming an IPE policy indicated by CONFIG_IPE_BOOT_POLICY into a c-string literal that is parsed at kernel startup as an unsigned policy. Signed-off-by: Deven Bowers Signed-off-by: Fan Wu Signed-off-by: Paul Moore

arch: um: rust: Add i386 support for Rust

2024-07-03T10:22:22Z

At present, Rust in the kernel only supports 64-bit x86, so UML has followed suit. However, it's significantly easier to support 32-bit i386 on UML than on bare metal, as UML does not use the -mregparm option (which alters the ABI), which is not yet supported by rustc[1]. Add support for CONFIG_RUST on um/i386, by adding a new target config to generate_rust_target, and replacing various checks on CONFIG_X86_64 to also support CONFIG_X86_32. We still use generate_rust_target, rather than a built-in rustc target, in order to match x86_64, provide a future place for -mregparm, and more easily disable floating point instructions. With these changes, the KUnit tests pass with: kunit.py run --make_options LLVM=1 --kconfig_add CONFIG_RUST=y --kconfig_add CONFIG_64BIT=n --kconfig_add CONFIG_FORTIFY_SOURCE=n An earlier version of these changes was proposed on the Rust-for-Linux github[2]. [1]: https://github.com/rust-lang/rust/issues/116972 [2]: https://github.com/Rust-for-Linux/linux/pull/966 Signed-off-by: David Gow Link: https://patch.msgid.link/20240604224052.3138504-1-davidgow@google.com Signed-off-by: Johannes Berg

LoongArch: rust: Switch to use built-in rustc target

2024-05-14T04:24:18Z

This commit switches to use the LoongArch's built-in rustc target 'loongarch64-unknown-none-softfloat'. The Rust samples have been tested. Acked-by: Miguel Ojeda Tested-by: Miguel Ojeda Signed-off-by: WANG Rui Signed-off-by: Huacai Chen

Merge tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

2024-03-22T17:22:45Z

Pull LoongArch updates from Huacai Chen: - Add objtool support for LoongArch - Add ORC stack unwinder support for LoongArch - Add kernel livepatching support for LoongArch - Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig - Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig - Some bug fixes and other small changes * tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: LoongArch/crypto: Clean up useless assignment operations LoongArch: Define the __io_aw() hook as mmiowb() LoongArch: Remove superfluous flush_dcache_page() definition LoongArch: Move {dmw,tlb}_virt_to_page() definition to page.h LoongArch: Change __my_cpu_offset definition to avoid mis-optimization LoongArch: Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig LoongArch: Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig LoongArch: Add kernel livepatching support LoongArch: Add ORC stack unwinder support objtool: Check local label in read_unwind_hints() objtool: Check local label in add_dead_ends() objtool/LoongArch: Enable orc to be built objtool/x86: Separate arch-specific and generic parts objtool/LoongArch: Implement instruction decoder objtool/LoongArch: Enable objtool to be built