user/sven/linux.git/include/linux/module.h, branch v6.13.1

module: fix writing of livepatch relocations in ROX text

2025-01-13T03:03:37Z

A livepatch module can contain a special relocation section .klp.rela.. to apply its relocations at the appropriate time and to additionally access local and unexported symbols. When points to another module, such relocations are processed separately from the regular module relocation process. For instance, only when the target 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] [ 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] [ 25.850553] Modules linked in: deku(OK+) uinput [ 25.851408] CR2: 00000000000012ba [ 25.852085] ---[ end trace 0000000000000000 ]--- The problem is that the .klp.rela.. 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 Reported-by: Marek Maslanka Closes: https://lore.kernel.org/linux-modules/CAGcaFA2hdThQV6mjD_1_U+GNHThv84+MQvMWLgEuX+LVbAyDxg@mail.gmail.com/ Reviewed-by: Petr Mladek Tested-by: Petr Mladek Cc: Joe Lawrence Cc: Josh Poimboeuf Cc: Luis Chamberlain Cc: Mike Rapoport (Microsoft) Cc: Petr Mladek Signed-off-by: Andrew Morton

module: Convert symbol namespace to string literal

2024-12-02T19:34:44Z

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 Signed-off-by: Peter Zijlstra (Intel) Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH Signed-off-by: Linus Torvalds

Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2024-11-30T21:41:50Z

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() ...

modpost: rename alias symbol for MODULE_DEVICE_TABLE()

2024-11-27T23:46:02Z

This commit renames the alias symbol, __mod____device_table to __mod_device_table____. 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

module: prepare to handle ROX allocations for text

2024-11-07T22:25:15Z

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) Reviewd-by: Luis Chamberlain Tested-by: kdevops Cc: Andreas Larsson Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Borislav Petkov (AMD) Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Christoph Hellwig Cc: Dave Hansen Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Helge Deller Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Kent Overstreet Cc: Liam R. Howlett Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Oleg Nesterov Cc: Palmer Dabbelt Cc: Peter Zijlstra Cc: Richard Weinberger Cc: Russell King Cc: Song Liu Cc: Stafford Horne Cc: Steven Rostedt (Google) Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Uladzislau Rezki (Sony) Cc: Vineet Gupta Cc: Will Deacon Signed-off-by: Andrew Morton

Merge tag 'modules-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

2024-07-23T18:43:40Z

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

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-07-09T15:01:46Z

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

module: create weak dependecies

2024-07-01T01:57:20Z

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 Reviewed-by: Lucas De Marchi Signed-off-by: Luis Chamberlain

kallsyms: rework symbol lookup return codes

2024-06-27T15:43:40Z

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 Reviewed-by: Luis Chamberlain Acked-by: Steven Rostedt (Google) Signed-off-by: Arnd Bergmann

module, bpf: Store BTF base pointer in struct module

2024-06-21T21:45:07Z

...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 Signed-off-by: Andrii Nakryiko Reviewed-by: Luis Chamberlain Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240620091733.1967885-3-alan.maguire@oracle.com