user/sven/linux.git/kernel/livepatch, branch v6.1.162

livepatch: Match old_sympos 0 and 1 in klp_find_func()

2026-01-11T14:18:40Z

[ Upstream commit 139560e8b973402140cafeb68c656c1374bd4c20 ] When there is only one function of the same name, old_sympos of 0 and 1 are logically identical. Match them in klp_find_func(). This is to avoid a corner case with different toolchain behavior. In this specific issue, two versions of kpatch-build were used to build livepatch for the same kernel. One assigns old_sympos == 0 for unique local functions, the other assigns old_sympos == 1 for unique local functions. Both versions work fine by themselves. (PS: This behavior change was introduced in a downstream version of kpatch-build. This change does not exist in upstream kpatch-build.) However, during livepatch upgrade (with the replace flag set) from a patch built with one version of kpatch-build to the same fix built with the other version of kpatch-build, livepatching fails with errors like: [ 14.218706] sysfs: cannot create duplicate filename 'xxx/somefunc,1' ... [ 14.219466] Call Trace: [ 14.219468] [ 14.219469] dump_stack_lvl+0x47/0x60 [ 14.219474] sysfs_warn_dup.cold+0x17/0x27 [ 14.219476] sysfs_create_dir_ns+0x95/0xb0 [ 14.219479] kobject_add_internal+0x9e/0x260 [ 14.219483] kobject_add+0x68/0x80 [ 14.219485] ? kstrdup+0x3c/0xa0 [ 14.219486] klp_enable_patch+0x320/0x830 [ 14.219488] patch_init+0x443/0x1000 [ccc_0_6] [ 14.219491] ? 0xffffffffa05eb000 [ 14.219492] do_one_initcall+0x2e/0x190 [ 14.219494] do_init_module+0x67/0x270 [ 14.219496] init_module_from_file+0x75/0xa0 [ 14.219499] idempotent_init_module+0x15a/0x240 [ 14.219501] __x64_sys_finit_module+0x61/0xc0 [ 14.219503] do_syscall_64+0x5b/0x160 [ 14.219505] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 14.219507] RIP: 0033:0x7f545a4bd96d ... [ 14.219516] kobject: kobject_add_internal failed for somefunc,1 with -EEXIST, don't try to register things with the same name ... This happens because klp_find_func() thinks somefunc with old_sympos==0 is not the same as somefunc with old_sympos==1, and klp_add_object_nops adds another xxx/func,1 to the list of functions to patch. Signed-off-by: Song Liu Acked-by: Josh Poimboeuf [pmladek@suse.com: Fixed some typos.] Reviewed-by: Petr Mladek Tested-by: Petr Mladek Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin

livepatch: Fix missing newline character in klp_resolve_symbols()

2023-11-20T10:52:10Z

[ Upstream commit 67e18e132f0fd738f8c8cac3aa1420312073f795 ] Without the newline character, the log may not be printed immediately after the error occurs. Fixes: ca376a937486 ("livepatch: Prevent module-specific KLP rela sections from referencing vmlinux symbols") Signed-off-by: Zheng Yejian Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20230914072644.4098857-1-zhengyejian1@huawei.com Signed-off-by: Sasha Levin

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 race between fork and KLP transition

2022-09-01T12:53:18Z

The KLP transition code depends on the TIF_PATCH_PENDING and the task->patch_state to stay in sync. On a normal (forward) transition, TIF_PATCH_PENDING will be set on every task in the system, while on a reverse transition (after a failed forward one) first TIF_PATCH_PENDING will be cleared from every task, followed by it being set on tasks that need to be transitioned back to the original code. However, the fork code copies over the TIF_PATCH_PENDING flag from the parent to the child early on, in dup_task_struct and setup_thread_stack. Much later, klp_copy_process will set child->patch_state to match that of the parent. However, the parent's patch_state may have been changed by KLP loading or unloading since it was initially copied over into the child. This results in the KLP code occasionally hitting this warning in klp_complete_transition: for_each_process_thread(g, task) { WARN_ON_ONCE(test_tsk_thread_flag(task, TIF_PATCH_PENDING)); task->patch_state = KLP_UNDEFINED; } Set, or clear, the TIF_PATCH_PENDING flag in the child task depending on whether or not it is needed at the time klp_copy_process is called, at a point in copy_process where the tasklist_lock is held exclusively, preventing races with the KLP code. The KLP code does have a few places where the state is changed without the tasklist_lock held, but those should not cause problems because klp_update_patch_state(current) cannot be called while the current task is in the middle of fork, klp_check_and_switch_task() which is called under the pi_lock, which prevents rescheduling, and manipulation of the patch state of idle tasks, which do not fork. This should prevent this warning from triggering again in the future, and close the race for both normal and reverse transitions. Signed-off-by: Rik van Riel Reported-by: Breno Leitao Reviewed-by: Petr Mladek Acked-by: Josh Poimboeuf Fixes: d83a7cb375ee ("livepatch: change to a per-task consistency model") Cc: stable@kernel.org Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220808150019.03d6a67b@imladris.surriel.com

Merge tag 'livepatching-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

2022-06-02T15:55:01Z

Pull livepatching cleanup from Petr Mladek: - Remove duplicated livepatch code [Christophe] * tag 'livepatching-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Remove klp_arch_set_pc() and asm/livepatch.h

livepatch: Remove klp_arch_set_pc() and asm/livepatch.h

2022-05-24T06:46:37Z

All three versions of klp_arch_set_pc() do exactly the same: they call ftrace_instruction_pointer_set(). Call ftrace_instruction_pointer_set() directly and remove klp_arch_set_pc(). As klp_arch_set_pc() was the only thing remaining in asm/livepatch.h on x86 and s390, remove asm/livepatch.h livepatch.h remains on powerpc but its content is exclusively used by powerpc specific code. Signed-off-by: Christophe Leroy Acked-by: Petr Mladek Acked-by: Peter Zijlstra (Intel) Acked-by: Miroslav Benes Signed-off-by: Petr Mladek