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2025-02-06kbuild: keep symbols for symbol_get() even with CONFIG_TRIM_UNUSED_KSYMSMasahiro Yamada
Linus observed that the symbol_request(utf8_data_table) call fails when CONFIG_UNICODE=y and CONFIG_TRIM_UNUSED_KSYMS=y. symbol_get() relies on the symbol data being present in the ksymtab for symbol lookups. However, EXPORT_SYMBOL_GPL(utf8_data_table) is dropped due to CONFIG_TRIM_UNUSED_KSYMS, as no module references it in this case. Probably, this has been broken since commit dbacb0ef670d ("kconfig option for TRIM_UNUSED_KSYMS"). This commit addresses the issue by leveraging modpost. Symbol names passed to symbol_get() are recorded in the special .no_trim_symbol section, which is then parsed by modpost to forcibly keep such symbols. The .no_trim_symbol section is discarded by the linker scripts, so there is no impact on the size of the final vmlinux or modules. This commit cannot resolve the issue for direct calls to __symbol_get() because the symbol name is not known at compile-time. Although symbol_get() may eventually be deprecated, this workaround should be good enough meanwhile. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-31Merge tag 'kbuild-v6.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 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 ...
2025-01-26module: Constify 'struct module_attribute'Thomas Weißschuh
These structs are never modified, move them to read-only memory. This makes the API clearer and also prepares for the constification of 'struct attribute' itself. While at it, also constify 'modinfo_attrs_count'. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-3-3790b53e0abf@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: Handle 'struct module_version_attribute' as constThomas Weißschuh
The structure is always read-only due to its placement in the read-only section __modver. Reflect this at its usage sites. Also prepare for the const handling of 'struct module_attribute' itself. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-2-3790b53e0abf@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-12module: fix writing of livepatch relocations in ROX textPetr Pavlu
A livepatch module can contain a special relocation section .klp.rela.<objname>.<secname> to apply its relocations at the appropriate time and to additionally access local and unexported symbols. When <objname> points to another module, such relocations are processed separately from the regular module relocation process. For instance, only when the target <objname> actually becomes loaded. With CONFIG_STRICT_MODULE_RWX, when the livepatch core decides to apply these relocations, their processing results in the following bug: [ 25.827238] BUG: unable to handle page fault for address: 00000000000012ba [ 25.827819] #PF: supervisor read access in kernel mode [ 25.828153] #PF: error_code(0x0000) - not-present page [ 25.828588] PGD 0 P4D 0 [ 25.829063] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI [ 25.829742] CPU: 2 UID: 0 PID: 452 Comm: insmod Tainted: G O K 6.13.0-rc4-00078-g059dd502b263 #7820 [ 25.830417] Tainted: [O]=OOT_MODULE, [K]=LIVEPATCH [ 25.830768] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014 [ 25.831651] RIP: 0010:memcmp+0x24/0x60 [ 25.832190] Code: [...] [ 25.833378] RSP: 0018:ffffa40b403a3ae8 EFLAGS: 00000246 [ 25.833637] RAX: 0000000000000000 RBX: ffff93bc81d8e700 RCX: ffffffffc0202000 [ 25.834072] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000000012ba [ 25.834548] RBP: ffffa40b403a3b68 R08: ffffa40b403a3b30 R09: 0000004a00000002 [ 25.835088] R10: ffffffffffffd222 R11: f000000000000000 R12: 0000000000000000 [ 25.835666] R13: ffffffffc02032ba R14: ffffffffc007d1e0 R15: 0000000000000004 [ 25.836139] FS: 00007fecef8c3080(0000) GS:ffff93bc8f900000(0000) knlGS:0000000000000000 [ 25.836519] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 25.836977] CR2: 00000000000012ba CR3: 0000000002f24000 CR4: 00000000000006f0 [ 25.837442] Call Trace: [ 25.838297] <TASK> [ 25.841083] __write_relocate_add.constprop.0+0xc7/0x2b0 [ 25.841701] apply_relocate_add+0x75/0xa0 [ 25.841973] klp_write_section_relocs+0x10e/0x140 [ 25.842304] klp_write_object_relocs+0x70/0xa0 [ 25.842682] klp_init_object_loaded+0x21/0xf0 [ 25.842972] klp_enable_patch+0x43d/0x900 [ 25.843572] do_one_initcall+0x4c/0x220 [ 25.844186] do_init_module+0x6a/0x260 [ 25.844423] init_module_from_file+0x9c/0xe0 [ 25.844702] idempotent_init_module+0x172/0x270 [ 25.845008] __x64_sys_finit_module+0x69/0xc0 [ 25.845253] do_syscall_64+0x9e/0x1a0 [ 25.845498] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 25.846056] RIP: 0033:0x7fecef9eb25d [ 25.846444] Code: [...] [ 25.847563] RSP: 002b:00007ffd0c5d6de8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 25.848082] RAX: ffffffffffffffda RBX: 000055b03f05e470 RCX: 00007fecef9eb25d [ 25.848456] RDX: 0000000000000000 RSI: 000055b001e74e52 RDI: 0000000000000003 [ 25.848969] RBP: 00007ffd0c5d6ea0 R08: 0000000000000040 R09: 0000000000004100 [ 25.849411] R10: 00007fecefac7b20 R11: 0000000000000246 R12: 000055b001e74e52 [ 25.849905] R13: 0000000000000000 R14: 000055b03f05e440 R15: 0000000000000000 [ 25.850336] </TASK> [ 25.850553] Modules linked in: deku(OK+) uinput [ 25.851408] CR2: 00000000000012ba [ 25.852085] ---[ end trace 0000000000000000 ]--- The problem is that the .klp.rela.<objname>.<secname> relocations are processed after the module was already formed and mod->rw_copy was reset. However, the code in __write_relocate_add() calls module_writable_address() which translates the target address 'loc' still to 'loc + (mem->rw_copy - mem->base)', with mem->rw_copy now being 0. Fix the problem by returning directly 'loc' in module_writable_address() when the module is already formed. Function __write_relocate_add() knows to use text_poke() in such a case. Link: https://lkml.kernel.org/r/20250107153507.14733-1-petr.pavlu@suse.com Fixes: 0c133b1e78cd ("module: prepare to handle ROX allocations for text") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reported-by: Marek Maslanka <mmaslanka@google.com> Closes: https://lore.kernel.org/linux-modules/CAGcaFA2hdThQV6mjD_1_U+GNHThv84+MQvMWLgEuX+LVbAyDxg@mail.gmail.com/ Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-10module: get symbol CRC back to unsignedMasahiro Yamada
Commit 71810db27c1c ("modversions: treat symbol CRCs as 32 bit quantities") changed the CRC fields to s32 because the __kcrctab and __kcrctab_gpl sections contained relative references to the actual CRC values stored in the .rodata section when CONFIG_MODULE_REL_CRCS=y. Commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") removed this complexity. Now, the __kcrctab and __kcrctab_gpl sections directly contain the CRC values in all cases. The genksyms tool outputs unsigned 32-bit CRC values, so u32 is preferred over s32. No functional changes are intended. Regardless of this change, the CRC value is assigned to the u32 variable 'crcval' before the comparison, as seen in kernel/module/version.c: crcval = *crc; It was previously mandatory (but now optional) in order to avoid sign extension because the following line previously compared 'unsigned long' and 's32': if (versions[i].crc == crcval) return 1; versions[i].crc is still 'unsigned long' for backward compatibility. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
2024-12-02module: Convert symbol namespace to string literalPeter Zijlstra
Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-11-30Merge tag 'kbuild-v6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add generic support for built-in boot DTB files - Enable TAB cycling for dialog buttons in nconfig - Fix issues in streamline_config.pl - Refactor Kconfig - Add support for Clang's AutoFDO (Automatic Feedback-Directed Optimization) - Add support for Clang's Propeller, a profile-guided optimization. - Change the working directory to the external module directory for M= builds - Support building external modules in a separate output directory - Enable objtool for *.mod.o and additional kernel objects - Use lz4 instead of deprecated lz4c - Work around a performance issue with "git describe" - Refactor modpost * tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits) kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms gitignore: Don't ignore 'tags' directory kbuild: add dependency from vmlinux to resolve_btfids modpost: replace tdb_hash() with hash_str() kbuild: deb-pkg: add python3:native to build dependency genksyms: reduce indentation in export_symbol() modpost: improve error messages in device_id_check() modpost: rename alias symbol for MODULE_DEVICE_TABLE() modpost: rename variables in handle_moddevtable() modpost: move strstarts() to modpost.h modpost: convert do_usb_table() to a generic handler modpost: convert do_of_table() to a generic handler modpost: convert do_pnp_device_entry() to a generic handler modpost: convert do_pnp_card_entries() to a generic handler modpost: call module_alias_printf() from all do_*_entry() functions modpost: pass (struct module *) to do_*_entry() functions modpost: remove DEF_FIELD_ADDR_VAR() macro modpost: deduplicate MODULE_ALIAS() for all drivers modpost: introduce module_alias_printf() helper modpost: remove unnecessary check in do_acpi_entry() ...
2024-11-28modpost: rename alias symbol for MODULE_DEVICE_TABLE()Masahiro Yamada
This commit renames the alias symbol, __mod_<type>__<name>_device_table to __mod_device_table__<type>__<name>. This change simplifies the code slightly, as there is no longer a need to check both the prefix and suffix. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-07module: prepare to handle ROX allocations for textMike Rapoport (Microsoft)
In order to support ROX allocations for module text, it is necessary to handle modifications to the code, such as relocations and alternatives patching, without write access to that memory. One option is to use text patching, but this would make module loading extremely slow and will expose executable code that is not finally formed. A better way is to have memory allocated with ROX permissions contain invalid instructions and keep a writable, but not executable copy of the module text. The relocations and alternative patches would be done on the writable copy using the addresses of the ROX memory. Once the module is completely ready, the updated text will be copied to ROX memory using text patching in one go and the writable copy will be freed. Add support for that to module initialization code and provide necessary interfaces in execmem. Link: https://lkml.kernel.org/r/20241023162711.2579610-5-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewd-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: kdevops <kdevops@lists.linux.dev> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Song Liu <song@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-23Merge tag 'modules-6.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull module update from Luis Chamberlain: "This is a super boring development cycle this time around for modules, there is only one patch in this pull request. The patch deals with a corner case set of dependencies which is not resolved today to ensure users get the module they need on initramfs. Currently only one module is known to exist which needs this, however this can grow to capture other corner cases likely escaped and not reported before. The kernel change is just a section update, the real work is done and merged already on upstream kmod. This has been on linux-next for 3 weeks now" * tag 'modules-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: module: create weak dependecies
2024-07-09Merge tag 'for-netdev' of ↵Paolo Abeni
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-07-08 The following pull-request contains BPF updates for your *net-next* tree. We've added 102 non-merge commits during the last 28 day(s) which contain a total of 127 files changed, 4606 insertions(+), 980 deletions(-). The main changes are: 1) Support resilient split BTF which cuts down on duplication and makes BTF as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman. 2) Add support for dumping kfunc prototypes from BTF which enables both detecting as well as dumping compilable prototypes for kfuncs, from Daniel Xu. 3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement support for BPF exceptions, from Ilya Leoshkevich. 4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui. 5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option for skbs and add coverage along with it, from Vadim Fedorenko. 6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan. 7) Extend the BPF verifier to track the delta between linked registers in order to better deal with recent LLVM code optimizations, from Alexei Starovoitov. 8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should have been a pointer to the map value, from Benjamin Tissoires. 9) Extend BPF selftests to add regular expression support for test output matching and adjust some of the selftest when compiled under gcc, from Cupertino Miranda. 10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always iterates exactly once anyway, from Dan Carpenter. 11) Add the capability to offload the netfilter flowtable in XDP layer through kfuncs, from Florian Westphal & Lorenzo Bianconi. 12) Various cleanups in networking helpers in BPF selftests to shave off a few lines of open-coded functions on client/server handling, from Geliang Tang. 13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so that x86 JIT does not need to implement detection, from Leon Hwang. 14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an out-of-bounds memory access for dynpointers, from Matt Bobrowski. 15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as it might lead to problems on 32-bit archs, from Jiri Olsa. 16) Enhance traffic validation and dynamic batch size support in xsk selftests, from Tushar Vyavahare. bpf-next-for-netdev * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits) selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature bpf: helpers: fix bpf_wq_set_callback_impl signature libbpf: Add NULL checks to bpf_object__{prev_map,next_map} selftests/bpf: Remove exceptions tests from DENYLIST.s390x s390/bpf: Implement exceptions s390/bpf: Change seen_reg to a mask bpf: Remove unnecessary loop in task_file_seq_get_next() riscv, bpf: Optimize stack usage of trampoline bpf, devmap: Add .map_alloc_check selftests/bpf: Remove arena tests from DENYLIST.s390x selftests/bpf: Add UAF tests for arena atomics selftests/bpf: Introduce __arena_global s390/bpf: Support arena atomics s390/bpf: Enable arena s390/bpf: Support address space cast instruction s390/bpf: Support BPF_PROBE_MEM32 s390/bpf: Land on the next JITed instruction after exception s390/bpf: Introduce pre- and post- probe functions s390/bpf: Get rid of get_probe_mem_regno() ... ==================== Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-30module: create weak dependeciesJose Ignacio Tornos Martinez
It has been seen that for some network mac drivers (i.e. lan78xx) the related module for the phy is loaded dynamically depending on the current hardware. In this case, the associated phy is read using mdio bus and then the associated phy module is loaded during runtime (kernel function phy_request_driver_module). However, no software dependency is defined, so the user tools will no be able to get this dependency. For example, if dracut is used and the hardware is present, lan78xx will be included but no phy module will be added, and in the next restart the device will not work from boot because no related phy will be found during initramfs stage. In order to solve this, we could define a normal 'pre' software dependency in lan78xx module with all the possible phy modules (there may be some), but proceeding in that way, all the possible phy modules would be loaded while only one is necessary. The idea is to create a new type of dependency, that we are going to call 'weak' to be used only by the user tools that need to detect this situation. In that way, for example, dracut could check the 'weak' dependency of the modules involved in order to install these dependencies in initramfs too. That is, for the commented lan78xx module, defining the 'weak' dependency with the possible phy modules list, only the necessary phy would be loaded on demand keeping the same behavior, but all the possible phy modules would be available from initramfs. The 'weak' dependency support has been included in kmod: https://github.com/kmod-project/kmod/commit/05828b4a6e9327a63ef94df544a042b5e9ce4fe7 But, take into account that this can only be used if depmod is new enough. If it isn't, depmod will have the same behavior as always (keeping backward compatibility) and the information for the 'weak' dependency will not be provided. Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-06-27kallsyms: rework symbol lookup return codesArnd Bergmann
Building with W=1 in some configurations produces a false positive warning for kallsyms: kernel/kallsyms.c: In function '__sprint_symbol.isra': kernel/kallsyms.c:503:17: error: 'strcpy' source argument is the same as destination [-Werror=restrict] 503 | strcpy(buffer, name); | ^~~~~~~~~~~~~~~~~~~~ This originally showed up while building with -O3, but later started happening in other configurations as well, depending on inlining decisions. The underlying issue is that the local 'name' variable is always initialized to the be the same as 'buffer' in the called functions that fill the buffer, which gcc notices while inlining, though it could see that the address check always skips the copy. The calling conventions here are rather unusual, as all of the internal lookup functions (bpf_address_lookup, ftrace_mod_address_lookup, ftrace_func_address_lookup, module_address_lookup and kallsyms_lookup_buildid) already use the provided buffer and either return the address of that buffer to indicate success, or NULL for failure, but the callers are written to also expect an arbitrary other buffer to be returned. Rework the calling conventions to return the length of the filled buffer instead of its address, which is simpler and easier to follow as well as avoiding the warning. Leave only the kallsyms_lookup() calling conventions unchanged, since that is called from 16 different functions and adapting this would be a much bigger change. Link: https://lore.kernel.org/lkml/20200107214042.855757-1-arnd@arndb.de/ Link: https://lore.kernel.org/lkml/20240326130647.7bfb1d92@gandalf.local.home/ Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-06-21module, bpf: Store BTF base pointer in struct moduleAlan Maguire
...as this will allow split BTF modules with a base BTF representation (rather than the full vmlinux BTF at time of BTF encoding) to resolve their references to kernel types in a way that is more resilient to small changes in kernel types. This will allow modules that are not built every time the kernel is to provide more resilient BTF, rather than have it invalidated every time BTF ids for core kernel types change. Fields are ordered to avoid holes in struct module. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240620091733.1967885-3-alan.maguire@oracle.com
2024-05-14kprobes: remove dependency on CONFIG_MODULESMike Rapoport (IBM)
kprobes depended on CONFIG_MODULES because it has to allocate memory for code. Since code allocations are now implemented with execmem, kprobes can be enabled in non-modular kernels. Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the dependency of CONFIG_KPROBES on CONFIG_MODULES. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> [mcgrof: rebase in light of NEED_TASKS_RCU ] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-02-14Merge branch 'x86/bugs' into x86/core, to pick up pending changes before ↵Ingo Molnar
dependent patches Merge in pending alternatives patching infrastructure changes, before applying more patches. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-01-10Merge tag 'modules-6.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull module updates from Luis Chamberlain: "Just one cleanup and one documentation improvement change. No functional changes" * tag 'modules-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: kernel/module: improve documentation for try_module_get() module: Remove redundant TASK_UNINTERRUPTIBLE
2024-01-10x86/bugs: Rename CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINEBreno Leitao
Step 5/10 of the namespace unification of CPU mitigations related Kconfig options. [ mingo: Converted a few more uses in comments/messages as well. ] Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ariel Miculas <amiculas@cisco.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
2023-12-21kernel/module: improve documentation for try_module_get()Marco Pagani
The sentence "this call will fail if the module is already being removed" is potentially confusing and may contradict the rest of the documentation. If one tries to get a module that has already been removed using a stale pointer, the kernel will crash. Signed-off-by: Marco Pagani <marpagan@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-12-18kunit: add KUNIT_INIT_TABLE to init linker sectionRae Moar
Add KUNIT_INIT_TABLE to the INIT_DATA linker section. Alter the KUnit macros to create init tests: kunit_test_init_section_suites Update lib/kunit/executor.c to run both the suites in KUNIT_TABLE and KUNIT_INIT_TABLE. Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Rae Moar <rmoar@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-05-26kallsyms: remove unsed API lookup_symbol_attrsManinder Singh
with commit '7878c231dae0 ("slab: remove /proc/slab_allocators")' lookup_symbol_attrs usage is removed. Thus removing redundant API. Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-27Merge tag 'modules-6.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull module updates from Luis Chamberlain: "The summary of the changes for this pull requests is: - Song Liu's new struct module_memory replacement - Nick Alcock's MODULE_LICENSE() removal for non-modules - My cleanups and enhancements to reduce the areas where we vmalloc module memory for duplicates, and the respective debug code which proves the remaining vmalloc pressure comes from userspace. Most of the changes have been in linux-next for quite some time except the minor fixes I made to check if a module was already loaded prior to allocating the final module memory with vmalloc and the respective debug code it introduces to help clarify the issue. Although the functional change is small it is rather safe as it can only *help* reduce vmalloc space for duplicates and is confirmed to fix a bootup issue with over 400 CPUs with KASAN enabled. I don't expect stable kernels to pick up that fix as the cleanups would have also had to have been picked up. Folks on larger CPU systems with modules will want to just upgrade if vmalloc space has been an issue on bootup. Given the size of this request, here's some more elaborate details: The functional change change in this pull request is the very first patch from Song Liu which replaces the 'struct module_layout' with a new 'struct module_memory'. The old data structure tried to put together all types of supported module memory types in one data structure, the new one abstracts the differences in memory types in a module to allow each one to provide their own set of details. This paves the way in the future so we can deal with them in a cleaner way. If you look at changes they also provide a nice cleanup of how we handle these different memory areas in a module. This change has been in linux-next since before the merge window opened for v6.3 so to provide more than a full kernel cycle of testing. It's a good thing as quite a bit of fixes have been found for it. Jason Baron then made dynamic debug a first class citizen module user by using module notifier callbacks to allocate / remove module specific dynamic debug information. Nick Alcock has done quite a bit of work cross-tree to remove module license tags from things which cannot possibly be module at my request so to: a) help him with his longer term tooling goals which require a deterministic evaluation if a piece a symbol code could ever be part of a module or not. But quite recently it is has been made clear that tooling is not the only one that would benefit. Disambiguating symbols also helps efforts such as live patching, kprobes and BPF, but for other reasons and R&D on this area is active with no clear solution in sight. b) help us inch closer to the now generally accepted long term goal of automating all the MODULE_LICENSE() tags from SPDX license tags In so far as a) is concerned, although module license tags are a no-op for non-modules, tools which would want create a mapping of possible modules can only rely on the module license tag after the commit 8b41fc4454e ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"). Nick has been working on this *for years* and AFAICT I was the only one to suggest two alternatives to this approach for tooling. The complexity in one of my suggested approaches lies in that we'd need a possible-obj-m and a could-be-module which would check if the object being built is part of any kconfig build which could ever lead to it being part of a module, and if so define a new define -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've suggested would be to have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names mapping to modules always, and I don't think that's the case today. I am not aware of Nick or anyone exploring either of these options. Quite recently Josh Poimboeuf has pointed out that live patching, kprobes and BPF would benefit from resolving some part of the disambiguation as well but for other reasons. The function granularity KASLR (fgkaslr) patches were mentioned but Joe Lawrence has clarified this effort has been dropped with no clear solution in sight [1]. In the meantime removing module license tags from code which could never be modules is welcomed for both objectives mentioned above. Some developers have also welcomed these changes as it has helped clarify when a module was never possible and they forgot to clean this up, and so you'll see quite a bit of Nick's patches in other pull requests for this merge window. I just picked up the stragglers after rc3. LWN has good coverage on the motivation behind this work [2] and the typical cross-tree issues he ran into along the way. The only concrete blocker issue he ran into was that we should not remove the MODULE_LICENSE() tags from files which have no SPDX tags yet, even if they can never be modules. Nick ended up giving up on his efforts due to having to do this vetting and backlash he ran into from folks who really did *not understand* the core of the issue nor were providing any alternative / guidance. I've gone through his changes and dropped the patches which dropped the module license tags where an SPDX license tag was missing, it only consisted of 11 drivers. To see if a pull request deals with a file which lacks SPDX tags you can just use: ./scripts/spdxcheck.py -f \ $(git diff --name-only commid-id | xargs echo) You'll see a core module file in this pull request for the above, but that's not related to his changes. WE just need to add the SPDX license tag for the kernel/module/kmod.c file in the future but it demonstrates the effectiveness of the script. Most of Nick's changes were spread out through different trees, and I just picked up the slack after rc3 for the last kernel was out. Those changes have been in linux-next for over two weeks. The cleanups, debug code I added and final fix I added for modules were motivated by David Hildenbrand's report of boot failing on a systems with over 400 CPUs when KASAN was enabled due to running out of virtual memory space. Although the functional change only consists of 3 lines in the patch "module: avoid allocation if module is already present and ready", proving that this was the best we can do on the modules side took quite a bit of effort and new debug code. The initial cleanups I did on the modules side of things has been in linux-next since around rc3 of the last kernel, the actual final fix for and debug code however have only been in linux-next for about a week or so but I think it is worth getting that code in for this merge window as it does help fix / prove / evaluate the issues reported with larger number of CPUs. Userspace is not yet fixed as it is taking a bit of time for folks to understand the crux of the issue and find a proper resolution. Worst come to worst, I have a kludge-of-concept [3] of how to make kernel_read*() calls for modules unique / converge them, but I'm currently inclined to just see if userspace can fix this instead" Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0] Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1] Link: https://lwn.net/Articles/927569/ [2] Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3] * tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits) module: add debugging auto-load duplicate module support module: stats: fix invalid_mod_bytes typo module: remove use of uninitialized variable len module: fix building stats for 32-bit targets module: stats: include uapi/linux/module.h module: avoid allocation if module is already present and ready module: add debug stats to help identify memory pressure module: extract patient module check into helper modules/kmod: replace implementation with a semaphore Change DEFINE_SEMAPHORE() to take a number argument module: fix kmemleak annotations for non init ELF sections module: Ignore L0 and rename is_arm_mapping_symbol() module: Move is_arm_mapping_symbol() to module_symbol.h module: Sync code of is_arm_mapping_symbol() scripts/gdb: use mem instead of core_layout to get the module address interconnect: remove module-related code interconnect: remove MODULE_LICENSE in non-modules zswap: remove MODULE_LICENSE in non-modules zpool: remove MODULE_LICENSE in non-modules x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules ...
2023-04-26Merge tag 'net-next-6.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core: - Introduce a config option to tweak MAX_SKB_FRAGS. Increasing the default value allows for better BIG TCP performances - Reduce compound page head access for zero-copy data transfers - RPS/RFS improvements, avoiding unneeded NET_RX_SOFTIRQ when possible - Threaded NAPI improvements, adding defer skb free support and unneeded softirq avoidance - Address dst_entry reference count scalability issues, via false sharing avoidance and optimize refcount tracking - Add lockless accesses annotation to sk_err[_soft] - Optimize again the skb struct layout - Extends the skb drop reasons to make it usable by multiple subsystems - Better const qualifier awareness for socket casts BPF: - Add skb and XDP typed dynptrs which allow BPF programs for more ergonomic and less brittle iteration through data and variable-sized accesses - Add a new BPF netfilter program type and minimal support to hook BPF programs to netfilter hooks such as prerouting or forward - Add more precise memory usage reporting for all BPF map types - Adds support for using {FOU,GUE} encap with an ipip device operating in collect_md mode and add a set of BPF kfuncs for controlling encap params - Allow BPF programs to detect at load time whether a particular kfunc exists or not, and also add support for this in light skeleton - Bigger batch of BPF verifier improvements to prepare for upcoming BPF open-coded iterators allowing for less restrictive looping capabilities - Rework RCU enforcement in the verifier, add kptr_rcu and enforce BPF programs to NULL-check before passing such pointers into kfunc - Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and in local storage maps - Enable RCU semantics for task BPF kptrs and allow referenced kptr tasks to be stored in BPF maps - Add support for refcounted local kptrs to the verifier for allowing shared ownership, useful for adding a node to both the BPF list and rbtree - Add BPF verifier support for ST instructions in convert_ctx_access() which will help new -mcpu=v4 clang flag to start emitting them - Add ARM32 USDT support to libbpf - Improve bpftool's visual program dump which produces the control flow graph in a DOT format by adding C source inline annotations Protocols: - IPv4: Allow adding to IPv4 address a 'protocol' tag. Such value indicates the provenance of the IP address - IPv6: optimize route lookup, dropping unneeded R/W lock acquisition - Add the handshake upcall mechanism, allowing the user-space to implement generic TLS handshake on kernel's behalf - Bridge: support per-{Port, VLAN} neighbor suppression, increasing resilience to nodes failures - SCTP: add support for Fair Capacity and Weighted Fair Queueing schedulers - MPTCP: delay first subflow allocation up to its first usage. This will allow for later better LSM interaction - xfrm: Remove inner/outer modes from input/output path. These are not needed anymore - WiFi: - reduced neighbor report (RNR) handling for AP mode - HW timestamping support - support for randomized auth/deauth TA for PASN privacy - per-link debugfs for multi-link - TC offload support for mac80211 drivers - mac80211 mesh fast-xmit and fast-rx support - enable Wi-Fi 7 (EHT) mesh support Netfilter: - Add nf_tables 'brouting' support, to force a packet to be routed instead of being bridged - Update bridge netfilter and ovs conntrack helpers to handle IPv6 Jumbo packets properly, i.e. fetch the packet length from hop-by-hop extension header. This is needed for BIT TCP support - The iptables 32bit compat interface isn't compiled in by default anymore - Move ip(6)tables builtin icmp matches to the udptcp one. This has the advantage that icmp/icmpv6 match doesn't load the iptables/ip6tables modules anymore when iptables-nft is used - Extended netlink error report for netdevice in flowtables and netdev/chains. Allow for incrementally add/delete devices to netdev basechain. Allow to create netdev chain without device Driver API: - Remove redundant Device Control Error Reporting Enable, as PCI core has already error reporting enabled at enumeration time - Move Multicast DB netlink handlers to core, allowing devices other then bridge to use them - Allow the page_pool to directly recycle the pages from safely localized NAPI - Implement lockless TX queue stop/wake combo macros, allowing for further code de-duplication and sanitization - Add YNL support for user headers and struct attrs - Add partial YNL specification for devlink - Add partial YNL specification for ethtool - Add tc-mqprio and tc-taprio support for preemptible traffic classes - Add tx push buf len param to ethtool, specifies the maximum number of bytes of a transmitted packet a driver can push directly to the underlying device - Add basic LED support for switch/phy - Add NAPI documentation, stop relaying on external links - Convert dsa_master_ioctl() to netdev notifier. This is a preparatory work to make the hardware timestamping layer selectable by user space - Add transceiver support and improve the error messages for CAN-FD controllers New hardware / drivers: - Ethernet: - AMD/Pensando core device support - MediaTek MT7981 SoC - MediaTek MT7988 SoC - Broadcom BCM53134 embedded switch - Texas Instruments CPSW9G ethernet switch - Qualcomm EMAC3 DWMAC ethernet - StarFive JH7110 SoC - NXP CBTX ethernet PHY - WiFi: - Apple M1 Pro/Max devices - RealTek rtl8710bu/rtl8188gu - RealTek rtl8822bs, rtl8822cs and rtl8821cs SDIO chipset - Bluetooth: - Realtek RTL8821CS, RTL8851B, RTL8852BS - Mediatek MT7663, MT7922 - NXP w8997 - Actions Semi ATS2851 - QTI WCN6855 - Marvell 88W8997 - Can: - STMicroelectronics bxcan stm32f429 Drivers: - Ethernet NICs: - Intel (1G, icg): - add tracking and reporting of QBV config errors - add support for configuring max SDU for each Tx queue - Intel (100G, ice): - refactor mailbox overflow detection to support Scalable IOV - GNSS interface optimization - Intel (i40e): - support XDP multi-buffer - nVidia/Mellanox: - add the support for linux bridge multicast offload - enable TC offload for egress and engress MACVLAN over bond - add support for VxLAN GBP encap/decap flows offload - extend packet offload to fully support libreswan - support tunnel mode in mlx5 IPsec packet offload - extend XDP multi-buffer support - support MACsec VLAN offload - add support for dynamic msix vectors allocation - drop RX page_cache and fully use page_pool - implement thermal zone to report NIC temperature - Netronome/Corigine: - add support for multi-zone conntrack offload - Solarflare/Xilinx: - support offloading TC VLAN push/pop actions to the MAE - support TC decap rules - support unicast PTP - Other NICs: - Broadcom (bnxt): enforce software based freq adjustments only on shared PHC NIC - RealTek (r8169): refactor to addess ASPM issues during NAPI poll - Micrel (lan8841): add support for PTP_PF_PEROUT - Cadence (macb): enable PTP unicast - Engleder (tsnep): add XDP socket zero-copy support - virtio-net: implement exact header length guest feature - veth: add page_pool support for page recycling - vxlan: add MDB data path support - gve: add XDP support for GQI-QPL format - geneve: accept every ethertype - macvlan: allow some packets to bypass broadcast queue - mana: add support for jumbo frame - Ethernet high-speed switches: - Microchip (sparx5): Add support for TC flower templates - Ethernet embedded switches: - Broadcom (b54): - configure 6318 and 63268 RGMII ports - Marvell (mv88e6xxx): - faster C45 bus scan - Microchip: - lan966x: - add support for IS1 VCAP - better TX/RX from/to CPU performances - ksz9477: add ETS Qdisc support - ksz8: enhance static MAC table operations and error handling - sama7g5: add PTP capability - NXP (ocelot): - add support for external ports - add support for preemptible traffic classes - Texas Instruments: - add CPSWxG SGMII support for J7200 and J721E - Intel WiFi (iwlwifi): - preparation for Wi-Fi 7 EHT and multi-link support - EHT (Wi-Fi 7) sniffer support - hardware timestamping support for some devices/firwmares - TX beacon protection on newer hardware - Qualcomm 802.11ax WiFi (ath11k): - MU-MIMO parameters support - ack signal support for management packets - RealTek WiFi (rtw88): - SDIO bus support - better support for some SDIO devices (e.g. MAC address from efuse) - RealTek WiFi (rtw89): - HW scan support for 8852b - better support for 6 GHz scanning - support for various newer firmware APIs - framework firmware backwards compatibility - MediaTek WiFi (mt76): - P2P support - mesh A-MSDU support - EHT (Wi-Fi 7) support - coredump support" * tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2078 commits) net: phy: hide the PHYLIB_LEDS knob net: phy: marvell-88x2222: remove unnecessary (void*) conversions tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp. net: amd: Fix link leak when verifying config failed net: phy: marvell: Fix inconsistent indenting in led_blink_set lan966x: Don't use xdp_frame when action is XDP_TX tsnep: Add XDP socket zero-copy TX support tsnep: Add XDP socket zero-copy RX support tsnep: Move skb receive action to separate function tsnep: Add functions for queue enable/disable tsnep: Rework TX/RX queue initialization tsnep: Replace modulo operation with mask net: phy: dp83867: Add led_brightness_set support net: phy: Fix reading LED reg property drivers: nfc: nfcsim: remove return value check of `dev_dir` net: phy: dp83867: Remove unnecessary (void*) conversions net: ethtool: coalesce: try to make user settings stick twice net: mana: Check if netdev/napi_alloc_frag returns single page net: mana: Rename mana_refill_rxoob and remove some empty lines net: veth: add page_pool stats ...
2023-04-05kallsyms: move module-related functions under correct configsViktor Malik
Functions for searching module kallsyms should have non-empty definitions only if CONFIG_MODULES=y and CONFIG_KALLSYMS=y. Until now, only CONFIG_MODULES check was used for many of these, which may have caused complilation errors on some configs. This patch moves all relevant functions under the correct configs. Fixes: bd5314f8dd2d ("kallsyms, bpf: Move find_kallsyms_symbol_value out of internal header") Signed-off-by: Viktor Malik <vmalik@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202303181535.RFDCnz3E-lkp@intel.com/ Link: https://lore.kernel.org/r/20230330102001.2183693-1-vmalik@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-19kallsyms: Delete an unused parameter related to ↵Zhen Lei
{module_}kallsyms_on_each_symbol() The parameter 'struct module *' in the hook function associated with {module_}kallsyms_on_each_symbol() is no longer used. Delete it. Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-03-17kallsyms, bpf: Move find_kallsyms_symbol_value out of internal headerViktor Malik
Moving find_kallsyms_symbol_value from kernel/module/internal.h to include/linux/module.h. The reason is that internal.h is not prepared to be included when CONFIG_MODULES=n. find_kallsyms_symbol_value is used by kernel/bpf/verifier.c and including internal.h from it (without modules) leads into a compilation error: In file included from ../include/linux/container_of.h:5, from ../include/linux/list.h:5, from ../include/linux/timer.h:5, from ../include/linux/workqueue.h:9, from ../include/linux/bpf.h:10, from ../include/linux/bpf-cgroup.h:5, from ../kernel/bpf/verifier.c:7: ../kernel/bpf/../module/internal.h: In function 'mod_find': ../include/linux/container_of.h:20:54: error: invalid use of undefined type 'struct module' 20 | static_assert(__same_type(*(ptr), ((type *)0)->member) || \ | ^~ [...] This patch fixes the above error. Fixes: 31bf1dbccfb0 ("bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Viktor Malik <vmalik@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/oe-kbuild-all/202303161404.OrmfCy09-lkp@intel.com/ Link: https://lore.kernel.org/bpf/20230317095601.386738-1-vmalik@redhat.com
2023-03-10kernel/module: add documentation for try_module_get()Luis Chamberlain
There is quite a bit of tribal knowledge around proper use of try_module_get() and requiring *somehow* the module to still exist to use this call in a way that is safe. Document this bit of tribal knowledge. To be clear, you should only use try_module_get() *iff* you are 100% sure the module already does exist and is not on its way out. You can be sure the module still exists and is alive through: 1) Direct protection with its refcount: you know some earlier caller called __module_get() safely 2) Implied protection: there is an implied protection against module removal Having an idea of when you are sure __module_get() might be called earlier is easy to understand however the implied protection requires an example. We use sysfs an an example for implied protection without a direct module reference count bump. kernfs / sysfs uses its own internal reference counting for files being actively used, when such file are active they completely prevent the module from being removed. kernfs protects this with its kernfs_active(). Effort has been put into verifying the kernfs implied protection works by using a currently out-of-tree test_sysfs selftest test #32 [0]: ./tools/testing/selftests/sysfs/sysfs.sh -t 0032 Without kernfs / sysfs preventing module removal through its active reference count (kernfs_active()) the write would fail or worse, a crash would happen in this test and it does not. Similar safeguards are required for other users of try_module_get() *iff* they are not ensuring the above rule 1) is followed. [0] https://lore.kernel.org/lkml/20211029184500.2821444-4-mcgrof@kernel.org/ Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-03-09dyndbg: use the module notifier callbacksJason Baron
Bring dynamic debug in line with other subsystems by using the module notifier callbacks. This results in a net decrease in core module code. Additionally, Jim Cromie has a new dynamic debug classmap feature, which requires that jump labels be initialized prior to dynamic debug. Specifically, the new feature toggles a jump label from the existing dynamic_debug_setup() function. However, this does not currently work properly, because jump labels are initialized via the 'module_notify_list' notifier chain, which is invoked after the current call to dynamic_debug_setup(). Thus, this patch ensures that jump labels are initialized prior to dynamic debug by setting the dynamic debug notifier priority to 0, while jump labels have the higher priority of 1. Tested by Jim using his new test case, and I've verfied the correct printing via: # modprobe test_dynamic_debug dyndbg. Link: https://lore.kernel.org/lkml/20230113193016.749791-21-jim.cromie@gmail.com/ Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202302190427.9iIK2NfJ-lkp@intel.com/ Tested-by: Jim Cromie <jim.cromie@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> CC: Jim Cromie <jim.cromie@gmail.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-03-09module: make module_ktype structure constantThomas Weißschuh
Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the driver core allows the usage of const struct kobj_type. Take advantage of this to constify the structure definition to prevent modification at runtime. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-03-09module: replace module_layout with module_memorySong Liu
module_layout manages different types of memory (text, data, rodata, etc.) in one allocation, which is problematic for some reasons: 1. It is hard to enable CONFIG_STRICT_MODULE_RWX. 2. It is hard to use huge pages in modules (and not break strict rwx). 3. Many archs uses module_layout for arch-specific data, but it is not obvious how these data are used (are they RO, RX, or RW?) Improve the scenario by replacing 2 (or 3) module_layout per module with up to 7 module_memory per module: MOD_TEXT, MOD_DATA, MOD_RODATA, MOD_RO_AFTER_INIT, MOD_INIT_TEXT, MOD_INIT_DATA, MOD_INIT_RODATA, and allocating them separately. This adds slightly more entries to mod_tree (from up to 3 entries per module, to up to 7 entries per module). However, this at most adds a small constant overhead to __module_address(), which is expected to be fast. Various archs use module_layout for different data. These data are put into different module_memory based on their location in module_layout. IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT; data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc. module_memory simplifies quite some of the module code. For example, ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a different allocator for the data. kernel/module/strict_rwx.c is also much cleaner with module_memory. Signed-off-by: Song Liu <song@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-03-09livepatch: fix ELF typosAlexey Dobriyan
ELF is acronym. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/Y/3vWjQ/SBA5a0i5@p183
2023-02-23Merge tag 'modules-6.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull modules updates from Luis Chamberlain: "Nothing exciting at all for modules for v6.3. The biggest change is just the change of INSTALL_MOD_DIR from "extra" to "updates" which I found lingered for ages for no good reason while testing the CXL mock driver [0]. The CXL mock driver has no kconfig integration and requires building an external module... and re-building the *rest* of the production drivers. This mock driver when loaded but not the production ones will crash. All this can obviously be fixed by integrating kconfig semantics into such test module, however that's not desirable by the maintainer, and so sensible defaults must be used to ensure a default "make modules_install" will suffice for most distros which do not have a file like /etc/depmod.d/dist.conf with something like `search updates extra built-in`. Since most distros rely on kmod and since its inception the "updates" directory is always in the search path it makes more sense to use that than the "extra" which only *some* RH based systems rely on. All this stuff has been on linux-next for a while" [0] https://lkml.kernel.org/r/20221209062919.1096779-1-mcgrof@kernel.org * tag 'modules-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: Documentation: livepatch: module-elf-format: Remove local klp_modinfo definition module.h: Document klp_modinfo struct using kdoc module: Use kstrtobool() instead of strtobool() kernel/params.c: Use kstrtobool() instead of strtobool() test_kmod: stop kernel-doc warnings kbuild: Modify default INSTALL_MOD_DIR from extra to updates
2023-02-06module.h: Document klp_modinfo struct using kdocMarcos Paulo de Souza
Previously the documentation existed only in Documentation/livepatch directory. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-01-19livepatch: Improve the search performance of module_kallsyms_on_each_symbol()Zhen Lei
Currently we traverse all symbols of all modules to find the specified function for the specified module. But in reality, we just need to find the given module and then traverse all the symbols in it. Let's add a new parameter 'const char *modname' to function module_kallsyms_on_each_symbol(), then we can compare the module names directly in this function and call hook 'fn' after matching. If 'modname' is NULL, the symbols of all modules are still traversed for compatibility with other usage cases. Phase1: mod1-->mod2..(subsequent modules do not need to be compared) | Phase2: -->f1-->f2-->f3 Assuming that there are m modules, each module has n symbols on average, then the time complexity is reduced from O(m * n) to O(m) + O(n). Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Song Liu <song@kernel.org> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20230116101009.23694-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-13Merge tag 'net-next-6.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core: - Allow live renaming when an interface is up - Add retpoline wrappers for tc, improving considerably the performances of complex queue discipline configurations - Add inet drop monitor support - A few GRO performance improvements - Add infrastructure for atomic dev stats, addressing long standing data races - De-duplicate common code between OVS and conntrack offloading infrastructure - A bunch of UBSAN_BOUNDS/FORTIFY_SOURCE improvements - Netfilter: introduce packet parser for tunneled packets - Replace IPVS timer-based estimators with kthreads to scale up the workload with the number of available CPUs - Add the helper support for connection-tracking OVS offload BPF: - Support for user defined BPF objects: the use case is to allocate own objects, build own object hierarchies and use the building blocks to build own data structures flexibly, for example, linked lists in BPF - Make cgroup local storage available to non-cgroup attached BPF programs - Avoid unnecessary deadlock detection and failures wrt BPF task storage helpers - A relevant bunch of BPF verifier fixes and improvements - Veristat tool improvements to support custom filtering, sorting, and replay of results - Add LLVM disassembler as default library for dumping JITed code - Lots of new BPF documentation for various BPF maps - Add bpf_rcu_read_{,un}lock() support for sleepable programs - Add RCU grace period chaining to BPF to wait for the completion of access from both sleepable and non-sleepable BPF programs - Add support storing struct task_struct objects as kptrs in maps - Improve helper UAPI by explicitly defining BPF_FUNC_xxx integer values - Add libbpf *_opts API-variants for bpf_*_get_fd_by_id() functions Protocols: - TCP: implement Protective Load Balancing across switch links - TCP: allow dynamically disabling TCP-MD5 static key, reverting back to fast[er]-path - UDP: Introduce optional per-netns hash lookup table - IPv6: simplify and cleanup sockets disposal - Netlink: support different type policies for each generic netlink operation - MPTCP: add MSG_FASTOPEN and FastOpen listener side support - MPTCP: add netlink notification support for listener sockets events - SCTP: add VRF support, allowing sctp sockets binding to VRF devices - Add bridging MAC Authentication Bypass (MAB) support - Extensions for Ethernet VPN bridging implementation to better support multicast scenarios - More work for Wi-Fi 7 support, comprising conversion of all the existing drivers to internal TX queue usage - IPSec: introduce a new offload type (packet offload) allowing complete header processing and crypto offloading - IPSec: extended ack support for more descriptive XFRM error reporting - RXRPC: increase SACK table size and move processing into a per-local endpoint kernel thread, reducing considerably the required locking - IEEE 802154: synchronous send frame and extended filtering support, initial support for scanning available 15.4 networks - Tun: bump the link speed from 10Mbps to 10Gbps - Tun/VirtioNet: implement UDP segmentation offload support Driver API: - PHY/SFP: improve power level switching between standard level 1 and the higher power levels - New API for netdev <-> devlink_port linkage - PTP: convert existing drivers to new frequency adjustment implementation - DSA: add support for rx offloading - Autoload DSA tagging driver when dynamically changing protocol - Add new PCP and APPTRUST attributes to Data Center Bridging - Add configuration support for 800Gbps link speed - Add devlink port function attribute to enable/disable RoCE and migratable - Extend devlink-rate to support strict prioriry and weighted fair queuing - Add devlink support to directly reading from region memory - New device tree helper to fetch MAC address from nvmem - New big TCP helper to simplify temporary header stripping New hardware / drivers: - Ethernet: - Marvel Octeon CNF95N and CN10KB Ethernet Switches - Marvel Prestera AC5X Ethernet Switch - WangXun 10 Gigabit NIC - Motorcomm yt8521 Gigabit Ethernet - Microchip ksz9563 Gigabit Ethernet Switch - Microsoft Azure Network Adapter - Linux Automation 10Base-T1L adapter - PHY: - Aquantia AQR112 and AQR412 - Motorcomm YT8531S - PTP: - Orolia ART-CARD - WiFi: - MediaTek Wi-Fi 7 (802.11be) devices - RealTek rtw8821cu, rtw8822bu, rtw8822cu and rtw8723du USB devices - Bluetooth: - Broadcom BCM4377/4378/4387 Bluetooth chipsets - Realtek RTL8852BE and RTL8723DS - Cypress.CYW4373A0 WiFi + Bluetooth combo device Drivers: - CAN: - gs_usb: bus error reporting support - kvaser_usb: listen only and bus error reporting support - Ethernet NICs: - Intel (100G): - extend action skbedit to RX queue mapping - implement devlink-rate support - support direct read from memory - nVidia/Mellanox (mlx5): - SW steering improvements, increasing rules update rate - Support for enhanced events compression - extend H/W offload packet manipulation capabilities - implement IPSec packet offload mode - nVidia/Mellanox (mlx4): - better big TCP support - Netronome Ethernet NICs (nfp): - IPsec offload support - add support for multicast filter - Broadcom: - RSS and PTP support improvements - AMD/SolarFlare: - netlink extened ack improvements - add basic flower matches to offload, and related stats - Virtual NICs: - ibmvnic: introduce affinity hint support - small / embedded: - FreeScale fec: add initial XDP support - Marvel mv643xx_eth: support MII/GMII/RGMII modes for Kirkwood - TI am65-cpsw: add suspend/resume support - Mediatek MT7986: add RX wireless wthernet dispatch support - Realtek 8169: enable GRO software interrupt coalescing per default - Ethernet high-speed switches: - Microchip (sparx5): - add support for Sparx5 TC/flower H/W offload via VCAP - Mellanox mlxsw: - add 802.1X and MAC Authentication Bypass offload support - add ip6gre support - Embedded Ethernet switches: - Mediatek (mtk_eth_soc): - improve PCS implementation, add DSA untag support - enable flow offload support - Renesas: - add rswitch R-Car Gen4 gPTP support - Microchip (lan966x): - add full XDP support - add TC H/W offload via VCAP - enable PTP on bridge interfaces - Microchip (ksz8): - add MTU support for KSZ8 series - Qualcomm 802.11ax WiFi (ath11k): - support configuring channel dwell time during scan - MediaTek WiFi (mt76): - enable Wireless Ethernet Dispatch (WED) offload support - add ack signal support - enable coredump support - remain_on_channel support - Intel WiFi (iwlwifi): - enable Wi-Fi 7 Extremely High Throughput (EHT) PHY capabilities - 320 MHz channels support - RealTek WiFi (rtw89): - new dynamic header firmware format support - wake-over-WLAN support" * tag 'net-next-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2002 commits) ipvs: fix type warning in do_div() on 32 bit net: lan966x: Remove a useless test in lan966x_ptp_add_trap() net: ipa: add IPA v4.7 support dt-bindings: net: qcom,ipa: Add SM6350 compatible bnxt: Use generic HBH removal helper in tx path IPv6/GRO: generic helper to remove temporary HBH/jumbo header in driver selftests: forwarding: Add bridge MDB test selftests: forwarding: Rename bridge_mdb test bridge: mcast: Support replacement of MDB port group entries bridge: mcast: Allow user space to specify MDB entry routing protocol bridge: mcast: Allow user space to add (*, G) with a source list and filter mode bridge: mcast: Add support for (*, G) with a source list and filter mode bridge: mcast: Avoid arming group timer when (S, G) corresponds to a source bridge: mcast: Add a flag for user installed source entries bridge: mcast: Expose __br_multicast_del_group_src() bridge: mcast: Expose br_multicast_new_group_src() bridge: mcast: Add a centralized error path bridge: mcast: Place netlink policy before validation functions bridge: mcast: Split (*, G) and (S, G) addition into different functions bridge: mcast: Do not derive entry type from its filter mode ...
2022-11-11module: remove redundant module_sysfs_initialized variableRasmus Villemoes
The variable module_sysfs_initialized is used for checking whether module_kset has been initialized. Checking module_kset itself works just fine for that. This is a leftover from commit 7405c1e15edf ("kset: convert /sys/module to use kset_create"). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Miroslav Benes <mbenes@suse.cz> [mcgrof: adjusted commit log as suggested by Christophe Leroy] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-10-25kallsyms: Make module_kallsyms_on_each_symbol generally availableJiri Olsa
Making module_kallsyms_on_each_symbol generally available, so it can be used outside CONFIG_LIVEPATCH option in following changes. Rather than adding another ifdef option let's make the function generally available (when CONFIG_KALLSYMS and CONFIG_MODULES options are defined). Cc: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20221025134148.3300700-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-26cfi: Switch to -fsanitize=kcfiSami Tolvanen
Switch from Clang's original forward-edge control-flow integrity implementation to -fsanitize=kcfi, which is better suited for the kernel, as it doesn't require LTO, doesn't use a jump table that requires altering function references, and won't break cross-module function address equality. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-6-samitolvanen@google.com
2022-09-26cfi: Drop __CFI_ADDRESSABLESami Tolvanen
The __CFI_ADDRESSABLE macro is used for init_module and cleanup_module to ensure we have the address of the CFI jump table, and with CONFIG_X86_KERNEL_IBT to ensure LTO won't optimize away the symbols. As __CFI_ADDRESSABLE is no longer necessary with -fsanitize=kcfi, add a more flexible version of the __ADDRESSABLE macro and always ensure these symbols won't be dropped. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-5-samitolvanen@google.com
2022-07-11kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suitesDaniel Latypov
We currently store kunit suites in the .kunit_test_suites ELF section as a `struct kunit_suite***` (modulo some `const`s). For every test file, we store a struct kunit_suite** NULL-terminated array. This adds quite a bit of complexity to the test filtering code in the executor. Instead, let's just make the .kunit_test_suites section contain a single giant array of struct kunit_suite pointers, which can then be directly manipulated. This array is not NULL-terminated, and so none of the test filtering code needs to NULL-terminate anything. Tested-by: Maíra Canal <maira.canal@usp.br> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Signed-off-by: Daniel Latypov <dlatypov@google.com> Co-developed-by: David Gow <davidgow@google.com> Signed-off-by: David Gow <davidgow@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-07-11kunit: unify module and builtin suite definitionsJeremy Kerr
Currently, KUnit runs built-in tests and tests loaded from modules differently. For built-in tests, the kunit_test_suite{,s}() macro adds a list of suites in the .kunit_test_suites linker section. However, for kernel modules, a module_init() function is used to run the test suites. This causes problems if tests are included in a module which already defines module_init/exit_module functions, as they'll conflict with the kunit-provided ones. This change removes the kunit-defined module inits, and instead parses the kunit tests from their own section in the module. After module init, we call __kunit_test_suites_init() on the contents of that section, which prepares and runs the suite. This essentially unifies the module- and non-module kunit init formats. Tested-by: Maíra Canal <maira.canal@usp.br> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: Daniel Latypov <dlatypov@google.com> Signed-off-by: David Gow <davidgow@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-05-12module.h: simplify MODULE_IMPORT_NSGreg Kroah-Hartman
In commit ca321ec74322 ("module.h: allow #define strings to work with MODULE_IMPORT_NS") I fixed up the MODULE_IMPORT_NS() macro to allow defined strings to work with it. Unfortunatly I did it in a two-stage process, when it could just be done with the __stringify() macro as pointed out by Masahiro Yamada. Clean this up to only be one macro instead of two steps to achieve the same end result. Fixes: ca321ec74322 ("module.h: allow #define strings to work with MODULE_IMPORT_NS") Reported-by: Masahiro Yamada <masahiroy@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Matthias Maennich <maennich@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOCChristophe Leroy
Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC to allow architectures to request having modules data in vmalloc area instead of module area. This is required on powerpc book3s/32 in order to set data non executable, because it is not possible to set executability on page basis, this is done per 256 Mbytes segments. The module area has exec right, vmalloc area has noexec. This can also be useful on other powerpc/32 in order to maximize the chance of code being close enough to kernel core to avoid branch trampolines. Cc: Jason Wessel <jason.wessel@windriver.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mcgrof: rebased in light of kernel/module/kdb.c move] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05module: Move extra signature support out of core codeAaron Tomlin
No functional change. This patch migrates additional module signature check code from core module code into kernel/module/signing.c. Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05module: Move livepatch support to a separate fileAaron Tomlin
No functional change. This patch migrates livepatch support (i.e. used during module add/or load and remove/or deletion) from core module code into kernel/module/livepatch.c. At the moment it contains code to persist Elf information about a given livepatch module, only. The new file was added to MAINTAINERS. Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-01-17Merge branch 'modules-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull module updates from Luis Chamberlain: "The biggest change here is in-kernel support for module decompression. This change is being made to help support LSMs like LoadPin as otherwise it loses link between the source of kernel module on the disk and binary blob that is being loaded into the kernel. kmod decompression is still done by userspace even with this is done, both because there are no measurable gains in not doing so and as it adds a secondary extra check for validating the module before loading it into the kernel. The rest of the changes are minor, the only other change worth mentionin there is Jessica Yu is now bowing out of maintenance of modules as she's taking a break from work. While there were other changes posted for modules, those have not yet received much review of testing so I'm not yet comfortable in merging any of those changes yet." * 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: module: fix signature check failures when using in-kernel decompression kernel: Fix spelling mistake "compresser" -> "compressor" MAINTAINERS: add mailing lists for kmod and modules module.h: allow #define strings to work with MODULE_IMPORT_NS module: add in-kernel support for decompressing MAINTAINERS: Remove myself as modules maintainer module: Remove outdated comment
2022-01-11module.h: allow #define strings to work with MODULE_IMPORT_NSGreg Kroah-Hartman
The MODULE_IMPORT_NS() macro does not allow defined strings to work properly with it, so add a layer of indirection to allow this to happen. Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Matthias Maennich <maennich@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Matthias Maennich <maennich@google.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2021-12-13exit: Rename module_put_and_exit to module_put_and_kthread_exitEric W. Biederman
Update module_put_and_exit to call kthread_exit instead of do_exit. Change the name to reflect this change in functionality. All of the users of module_put_and_exit are causing the current kthread to exit so this change makes it clear what is happening. There is no functional change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-07-19printk: Userspace format indexing supportChris Down
We have a number of systems industry-wide that have a subset of their functionality that works as follows: 1. Receive a message from local kmsg, serial console, or netconsole; 2. Apply a set of rules to classify the message; 3. Do something based on this classification (like scheduling a remediation for the machine), rinse, and repeat. As a couple of examples of places we have this implemented just inside Facebook, although this isn't a Facebook-specific problem, we have this inside our netconsole processing (for alarm classification), and as part of our machine health checking. We use these messages to determine fairly important metrics around production health, and it's important that we get them right. While for some kinds of issues we have counters, tracepoints, or metrics with a stable interface which can reliably indicate the issue, in order to react to production issues quickly we need to work with the interface which most kernel developers naturally use when developing: printk. Most production issues come from unexpected phenomena, and as such usually the code in question doesn't have easily usable tracepoints or other counters available for the specific problem being mitigated. We have a number of lines of monitoring defence against problems in production (host metrics, process metrics, service metrics, etc), and where it's not feasible to reliably monitor at another level, this kind of pragmatic netconsole monitoring is essential. As one would expect, monitoring using printk is rather brittle for a number of reasons -- most notably that the message might disappear entirely in a new version of the kernel, or that the message may change in some way that the regex or other classification methods start to silently fail. One factor that makes this even harder is that, under normal operation, many of these messages are never expected to be hit. For example, there may be a rare hardware bug which one wants to detect if it was to ever happen again, but its recurrence is not likely or anticipated. This precludes using something like checking whether the printk in question was printed somewhere fleetwide recently to determine whether the message in question is still present or not, since we don't anticipate that it should be printed anywhere, but still need to monitor for its future presence in the long-term. This class of issue has happened on a number of occasions, causing unhealthy machines with hardware issues to remain in production for longer than ideal. As a recent example, some monitoring around blk_update_request fell out of date and caused semi-broken machines to remain in production for longer than would be desirable. Searching through the codebase to find the message is also extremely fragile, because many of the messages are further constructed beyond their callsite (eg. btrfs_printk and other module-specific wrappers, each with their own functionality). Even if they aren't, guessing the format and formulation of the underlying message based on the aesthetics of the message emitted is not a recipe for success at scale, and our previous issues with fleetwide machine health checking demonstrate as much. This provides a solution to the issue of silently changed or deleted printks: we record pointers to all printk format strings known at compile time into a new .printk_index section, both in vmlinux and modules. At runtime, this can then be iterated by looking at <debugfs>/printk/index/<module>, which emits the following format, both readable by humans and able to be parsed by machines: $ head -1 vmlinux; shuf -n 5 vmlinux # <level[,flags]> filename:line function "format" <5> block/blk-settings.c:661 disk_stack_limits "%s: Warning: Device %s is misaligned\n" <4> kernel/trace/trace.c:8296 trace_create_file "Could not create tracefs '%s' entry\n" <6> arch/x86/kernel/hpet.c:144 _hpet_print_config "hpet: %s(%d):\n" <6> init/do_mounts.c:605 prepare_namespace "Waiting for root device %s...\n" <6> drivers/acpi/osl.c:1410 acpi_no_auto_serialize_setup "ACPI: auto-serialization disabled\n" This mitigates the majority of cases where we have a highly-specific printk which we want to match on, as we can now enumerate and check whether the format changed or the printk callsite disappeared entirely in userspace. This allows us to catch changes to printks we monitor earlier and decide what to do about it before it becomes problematic. There is no additional runtime cost for printk callers or printk itself, and the assembly generated is exactly the same. Signed-off-by: Chris Down <chris@chrisdown.name> Cc: Petr Mladek <pmladek@suse.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Jessica Yu <jeyu@kernel.org> # for module.{c,h} Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/e42070983637ac5e384f17fbdbe86d19c7b212a5.1623775748.git.chris@chrisdown.name