user/sven/linux.git/kernel/livepatch, branch v5.17.6

livepatch: Fix build failure on 32 bits processors

2022-04-08T11:58:03Z

[ Upstream commit 2f293651eca3eacaeb56747dede31edace7329d2 ] 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 Signed-off-by: Sasha Levin

Merge tag 'livepatching-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

2022-01-16T08:08:13Z

Pull livepatching updates from Petr Mladek: - Correctly handle kobjects when a livepatch init fails - Avoid CPU hogging when searching for many livepatched symbols - Add livepatch API page into documentation * tag 'livepatching-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Avoid CPU hogging with cond_resched livepatch: Fix missing unlock on error in klp_enable_patch() livepatch: Fix kobject refcount bug on klp_init_patch_early failure path Documentation: livepatch: Add livepatch API page

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

Documentation: livepatch: Add livepatch API page

2021-12-23T10:35:53Z

The livepatch subsystem has several exported functions and objects with kerneldoc comments. Though the livepatch documentation contains handwritten descriptions of all of these exported functions, they are currently not pulled into the docs build using the kernel-doc directive. In order to allow readers of the documentation to see the full kerneldoc comments in the generated documentation files, this change adds a new Documentation/livepatch/api.rst page which contains kernel-doc directives to link the kerneldoc comments directly in the documentation. With this, all of the hand-written descriptions of the APIs now cross-reference the kerneldoc comments on the new Livepatching APIs page, and running ./scripts/find-unused-docs.sh on kernel/livepatch no longer shows any files as missing documentation. Note that all of the handwritten API descriptions were left alone with the exception of Documentation/livepatch/system-state.rst, which was updated to allow the cross-referencing to work correctly. The file now follows the cross-referencing formatting guidance specified in Documentation/doc-guide/kernel-doc.rst. Furthermore, some comments around klp_shadow_free_all() were updated to say <_, id> rather than <*, id> to match the rest of the file, and to prevent the docs build from emitting an "Inline emphasis start-string without end string" error. Signed-off-by: David Vernet Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20211221145743.4098360-1-void@manifault.com

Merge tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-11-02T03:05:19Z

Pull tracing updates from Steven Rostedt: - kprobes: Restructured stack unwinder to show properly on x86 when a stack dump happens from a kretprobe callback. - Fix to bootconfig parsing - Have tracefs allow owner and group permissions by default (only denying others). There's been pressure to allow non root to tracefs in a controlled fashion, and using groups is probably the safest. - Bootconfig memory managament updates. - Bootconfig clean up to have the tools directory be less dependent on changes in the kernel tree. - Allow perf to be traced by function tracer. - Rewrite of function graph tracer to be a callback from the function tracer instead of having its own trampoline (this change will happen on an arch by arch basis, and currently only x86_64 implements it). - Allow multiple direct trampolines (bpf hooks to functions) be batched together in one synchronization. - Allow histogram triggers to add variables that can perform calculations against the event's fields. - Use the linker to determine architecture callbacks from the ftrace trampoline to allow for proper parameter prototypes and prevent warnings from the compiler. - Extend histogram triggers to key off of variables. - Have trace recursion use bit magic to determine preempt context over if branches. - Have trace recursion disable preemption as all use cases do anyway. - Added testing for verification of tracing utilities. - Various small clean ups and fixes. * tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits) tracing/histogram: Fix semicolon.cocci warnings tracing/histogram: Fix documentation inline emphasis warning tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together tracing: Show size of requested perf buffer bootconfig: Initialize ret in xbc_parse_tree() ftrace: do CPU checking after preemption disabled ftrace: disable preemption when recursion locked tracing/histogram: Document expression arithmetic and constants tracing/histogram: Optimize division by a power of 2 tracing/histogram: Covert expr to const if both operands are constants tracing/histogram: Simplify handling of .sym-offset in expressions tracing: Fix operator precedence for hist triggers expression tracing: Add division and multiplication support for hist triggers tracing: Add support for creating hist trigger variables from literal selftests/ftrace: Stop tracing while reading the trace file by default MAINTAINERS: Update KPROBES and TRACING entries test_kprobes: Move it from kernel/ to lib/ docs, kprobes: Remove invalid URL and add new reference samples/kretprobes: Fix return value if register_kretprobe() failed lib/bootconfig: Fix the xbc_get_info kerneldoc ...

ftrace: disable preemption when recursion locked

2021-10-27T15:21:49Z

As the documentation explained, ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() were supposed to disable and enable preemption properly, however currently this work is done outside of the function, which could be missing by mistake. And since the internal using of trace_test_and_set_recursion() and trace_clear_recursion() also require preemption disabled, we can just merge the logical. This patch will make sure the preemption has been disabled when trace_test_and_set_recursion() return bit >= 0, and trace_clear_recursion() will enable the preemption if previously enabled. Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com CC: Petr Mladek Cc: Guo Ren Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Thomas Gleixner Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Joe Lawrence Cc: Masami Hiramatsu Cc: Nicholas Piggin Cc: Jisheng Zhang CC: Steven Rostedt CC: Miroslav Benes Reported-by: Abaci Suggested-by: Peter Zijlstra Signed-off-by: Michael Wang [ Removed extra line in comment - SDR ] Signed-off-by: Steven Rostedt (VMware)

sched,livepatch: Use wake_up_if_idle()

2021-10-14T11:09:25Z

Make sure to prod idle CPUs so they call klp_update_patch_state(). Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Acked-by: Vasily Gorbik Tested-by: Petr Mladek Tested-by: Vasily Gorbik # on s390 Link: https://lkml.kernel.org/r/20210929151723.162004989@infradead.org

sched,livepatch: Use task_call_func()

2021-10-07T11:51:15Z

Instead of frobbing around with scheduler internals, use the shiny new task_call_func() interface. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Acked-by: Vasily Gorbik Tested-by: Petr Mladek Tested-by: Vasily Gorbik # on s390 Link: https://lkml.kernel.org/r/20210929152428.709906138@infradead.org

livepatch: Replace deprecated CPU-hotplug functions.

2021-08-19T10:00:24Z

The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Miroslav Benes Cc: Petr Mladek Cc: Joe Lawrence Cc: live-patching@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Petr Mladek Signed-off-by: Jiri Kosina