user/sven/linux.git/kernel/livepatch/core.c, branch v6.1.57

Merge tag 'livepatching-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

2022-10-10T18:36:19Z

Pull livepatching updates from Petr Mladek: - Fix race between fork and livepatch transition revert - Add sysfs entry that shows "patched" state for each object (module) that can be livepatched by the given livepatch - Some clean up * tag 'livepatching-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: selftests/livepatch: add sysfs test livepatch: add sysfs entry "patched" for each klp_object selftests/livepatch: normalize sysctl error message livepatch: Add a missing newline character in klp_module_coming() livepatch: fix race between fork and KLP transition

Merge branch 'for-6.1/sysfs-patched-object' into for-linus

2022-10-05T11:00:03Z

kallsyms: increase maximum kernel symbol length to 512

2022-09-28T06:56:25Z

Rust symbols can become quite long due to namespacing introduced by modules, types, traits, generics, etc. For instance, the following code: pub mod my_module { pub struct MyType; pub struct MyGenericType(T); pub trait MyTrait { fn my_method() -> u32; } impl MyTrait for MyGenericType { fn my_method() -> u32 { 42 } } } generates a symbol of length 96 when using the upcoming v0 mangling scheme: _RNvXNtCshGpAVYOtgW1_7example9my_moduleINtB2_13MyGenericTypeNtB2_6MyTypeENtB2_7MyTrait9my_method At the moment, Rust symbols may reach up to 300 in length. Setting 512 as the maximum seems like a reasonable choice to keep some headroom. Reviewed-by: Kees Cook Reviewed-by: Petr Mladek Reviewed-by: Greg Kroah-Hartman Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Co-developed-by: Gary Guo Signed-off-by: Gary Guo Co-developed-by: Boqun Feng Signed-off-by: Boqun Feng Signed-off-by: Miguel Ojeda

livepatch: add sysfs entry "patched" for each klp_object

2022-09-23T14:06:18Z

Add per klp_object sysfs entry "patched". It makes it easier to debug typos in the module name. Signed-off-by: Song Liu Reviewed-by: Joe Lawrence [pmladek@suse.com: Updated kernel version when the sysfs file will be introduced] Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220902205208.3117798-2-song@kernel.org

livepatch: Add a missing newline character in klp_module_coming()

2022-09-01T14:27:59Z

The error message is not printed immediately because it does not end with a newline character. Before: root@localhost:~# insmod vmlinux.ko insmod: ERROR: could not insert module vmlinux.ko: Invalid parameters After: root@localhost:~# insmod vmlinux.ko [ 43.982558] livepatch: vmlinux.ko: invalid module name insmod: ERROR: could not insert module vmlinux.ko: Invalid parameters Fixes: dcf550e52f56 ("livepatch: Disallow vmlinux.ko") Signed-off-by: Zhen Lei Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220830112855.749-1-thunder.leizhen@huawei.com

livepatch: Fix build failure on 32 bits processors

2022-02-07T10:03:10Z

Trying to build livepatch on powerpc/32 results in: kernel/livepatch/core.c: In function 'klp_resolve_symbols': kernel/livepatch/core.c:221:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c:221:21: error: assignment to 'Elf32_Sym *' {aka 'struct elf32_sym *'} from incompatible pointer type 'Elf64_Sym *' {aka 'struct elf64_sym *'} [-Werror=incompatible-pointer-types] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c: In function 'klp_apply_section_relocs': kernel/livepatch/core.c:312:35: error: passing argument 1 of 'klp_resolve_symbols' from incompatible pointer type [-Werror=incompatible-pointer-types] 312 | ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname); | ^~~~~~~ | | | Elf32_Shdr * {aka struct elf32_shdr *} kernel/livepatch/core.c:193:44: note: expected 'Elf64_Shdr *' {aka 'struct elf64_shdr *'} but argument is of type 'Elf32_Shdr *' {aka 'struct elf32_shdr *'} 193 | static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab, | ~~~~~~~~~~~~^~~~~~~ Fix it by using the right types instead of forcing 64 bits types. Fixes: 7c8e2bdd5f0d ("livepatch: Apply vmlinux-specific KLP relocations early") Signed-off-by: Christophe Leroy Acked-by: Petr Mladek Acked-by: Joe Lawrence Acked-by: Miroslav Benes Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5288e11b018a762ea3351cc8fb2d4f15093a4457.1640017960.git.christophe.leroy@csgroup.eu

livepatch: Fix missing unlock on error in klp_enable_patch()

2022-01-04T12:57:19Z

Add missing unlock when try_module_get() fails in klp_enable_patch(). Fixes: 5ef3dd20555e8e8 ("livepatch: Fix kobject refcount bug on klp_init_patch_early failure path") Reported-by: Hulk Robot Signed-off-by: Yang Yingliang Acked-by: David Vernet Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20211225025115.475348-1-yangyingliang@huawei.com

livepatch: Fix kobject refcount bug on klp_init_patch_early failure path

2022-01-04T12:54:24Z

When enabling a klp patch with klp_enable_patch(), klp_init_patch_early() is invoked to initialize the kobjects for the patch itself, as well as the 'struct klp_object' and 'struct klp_func' objects that comprise it. However, there are some error paths in klp_enable_patch() where some kobjects may have been initialized with kobject_init(), but an error code is still returned due to e.g. a 'struct klp_object' having a NULL funcs pointer. In these paths, the initial reference of the kobject of the 'struct klp_patch' may never be released, along with one or more of its objects and their functions, as kobject_put() is not invoked on the cleanup path if klp_init_patch_early() returns an error code. For example, if an object entry such as the following were added to the sample livepatch module's klp patch, it would cause the vmlinux klp_object, and its klp_func which updates 'cmdline_proc_show', to never be released: static struct klp_object objs[] = { { /* name being NULL means vmlinux */ .funcs = funcs, }, { /* NULL funcs -- would cause reference leak */ .name = "kvm", }, { } }; Without this change, if CONFIG_DEBUG_KOBJECT is enabled, and the sample klp patch is loaded, the kobjects (the patch, the vmlinux 'struct klp_object', and its func) are observed as initialized, but never released, in the dmesg log output. With the change, these kobject references no longer fail to be released as the error case is properly handled before they are initialized. Signed-off-by: David Vernet Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Acked-by: Josh Poimboeuf Signed-off-by: Petr Mladek

kallsyms: refactor {,module_}kallsyms_on_each_symbol

2021-02-08T11:22:08Z

Require an explicit call to module_kallsyms_on_each_symbol to look for symbols in modules instead of the call from kallsyms_on_each_symbol, and acquire module_mutex inside of module_kallsyms_on_each_symbol instead of leaving that up to the caller. Note that this slightly changes the behavior for the livepatch code in that the symbols from vmlinux are not iterated anymore if objname is set, but that actually is the desired behavior in this case. Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu

module: use RCU to synchronize find_module

2021-02-08T11:21:40Z

Allow for a RCU-sched critical section around find_module, following the lower level find_module_all helper, and switch the two callers outside of module.c to use such a RCU-sched critical section instead of module_mutex. Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu