linux/kernel/kprobes.c, branch v5.14

Merge tag 'locking-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-07-11T18:06:09Z

Pull locking fixes from Ingo Molnar: - Fix a Sparc crash - Fix a number of objtool warnings - Fix /proc/lockdep output on certain configs - Restore a kprobes fail-safe * tag 'locking-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/atomic: sparc: Fix arch_cmpxchg64_local() kprobe/static_call: Restore missing static_call_text_reserved() static_call: Fix static_call_text_reserved() vs __init jump_label: Fix jump_label_text_reserved() vs __init locking/lockdep: Fix meaningless /proc/lockdep output of lock classes on !CONFIG_PROVE_LOCKING

kprobe/static_call: Restore missing static_call_text_reserved()

2021-07-05T08:47:16Z

Restore two hunks from commit: 6333e8f73b83 ("static_call: Avoid kprobes on inline static_call()s") that went walkabout in a Git merge commit. Fixes: 76d4acf22b48 ("Merge tag 'perf-kprobes-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") Signed-off-by: Peter Zijlstra (Intel) Acked-by: Masami Hiramatsu Link: https://lore.kernel.org/r/20210628113045.167127609@infradead.org Signed-off-by: Ingo Molnar

Merge tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-07-02T19:54:34Z

Pull powerpc updates from Michael Ellerman: - A big series refactoring parts of our KVM code, and converting some to C. - Support for ARCH_HAS_SET_MEMORY, and ARCH_HAS_STRICT_MODULE_RWX on some CPUs. - Support for the Microwatt soft-core. - Optimisations to our interrupt return path on 64-bit. - Support for userspace access to the NX GZIP accelerator on PowerVM on Power10. - Enable KUAP and KUEP by default on 32-bit Book3S CPUs. - Other smaller features, fixes & cleanups. Thanks to: Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Baokun Li, Benjamin Herrenschmidt, Bharata B Rao, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Finn Thain, Geoff Levand, Haren Myneni, Jason Wang, Jiapeng Chong, Joel Stanley, Jordan Niethe, Kajol Jain, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Paul Mackerras, Russell Currey, Sathvika Vasireddy, Shaokun Zhang, Stephen Rothwell, Sudeep Holla, Suraj Jitindar Singh, Tom Rix, Vaibhav Jain, YueHaibing, Zhang Jianhua, and Zhen Lei. * tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (218 commits) powerpc: Only build restart_table.c for 64s powerpc/64s: move ret_from_fork etc above __end_soft_masked powerpc/64s/interrupt: clean up interrupt return labels powerpc/64/interrupt: add missing kprobe annotations on interrupt exit symbols powerpc/64: enable MSR[EE] in irq replay pt_regs powerpc/64s/interrupt: preserve regs->softe for NMI interrupts powerpc/64s: add a table of implicit soft-masked addresses powerpc/64e: remove implicit soft-masking and interrupt exit restart logic powerpc/64e: fix CONFIG_RELOCATABLE build warnings powerpc/64s: fix hash page fault interrupt handler powerpc/4xx: Fix setup_kuep() on SMP powerpc/32s: Fix setup_{kuap/kuep}() on SMP powerpc/interrupt: Use names in check_return_regs_valid() powerpc/interrupt: Also use exit_must_hard_disable() on PPC32 powerpc/sysfs: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE powerpc/ptrace: Refactor regs_set_return_{msr/ip} powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip} powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi() powerpc/pseries/vas: Include irqdomain.h powerpc: mark local variables around longjmp as volatile ...

Merge branch 'akpm' (patches from Andrew)

2021-07-02T19:08:10Z

Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton : (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...

kprobes: remove duplicated strong free_insn_page in x86 and s390

2021-07-01T18:06:06Z

free_insn_page() in x86 and s390 is same with the common weak function in kernel/kprobes.c. Plus, the comment "Recover page to RW mode before releasing it" in x86 seems insensible to be there since resetting mapping is done by common code in vfree() of module_memfree(). So drop these two duplicated strong functions and related comment, then mark the common one in kernel/kprobes.c strong. Link: https://lkml.kernel.org/r/20210608065736.32656-1-song.bao.hua@hisilicon.com Signed-off-by: Barry Song Acked-by: Masami Hiramatsu Acked-by: Heiko Carstens Reviewed-by: Christoph Hellwig Cc: "H. Peter Anvin" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: "Naveen N. Rao" Cc: Anil S Keshavamurthy Cc: David S. Miller Cc: Qi Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kprobes: Remove kprobe::fault_handler

2021-06-01T14:00:08Z

The reason for kprobe::fault_handler(), as given by their comment: * We come here because instructions in the pre/post * handler caused the page_fault, this could happen * if handler tries to access user space by * copy_from_user(), get_user() etc. Let the * user-specified handler try to fix it first. Is just plain bad. Those other handlers are ran from non-preemptible context and had better use _nofault() functions. Also, there is no upstream usage of this. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Christoph Hellwig Acked-by: Masami Hiramatsu Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org

kprobes: Allow architectures to override optinsn page allocation

2021-05-23T10:51:35Z

Some architectures like powerpc require a non standard allocation of optinsn page, because module pages are too far from the kernel for direct branches. Define weak alloc_optinsn_page() and free_optinsn_page(), that fall back on alloc_insn_page() and free_insn_page() when not overridden by the architecture. Suggested-by: Masami Hiramatsu Signed-off-by: Christophe Leroy Reviewed-by: Naveen N. Rao Acked-by: Masami Hiramatsu Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/40a43d6df1fdf41ade36e9a46e60a4df774ca9f6.1620896780.git.christophe.leroy@csgroup.eu

kprobes: Fix to delay the kprobes jump optimization

2021-02-19T19:57:12Z

Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall") moved the kprobe setup in early_initcall(), which includes kprobe jump optimization. The kprobes jump optimizer involves synchronize_rcu_tasks() which depends on the ksoftirqd and rcu_spawn_tasks_*(). However, since those are setup in core_initcall(), kprobes jump optimizer can not run at the early_initcall(). To avoid this issue, make the kprobe optimization disabled in the early_initcall() and enables it in subsys_initcall(). Note that non-optimized kprobes is still available after early_initcall(). Only jump optimization is delayed. Link: https://lkml.kernel.org/r/161365856280.719838.12423085451287256713.stgit@devnote2 Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall") Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: RCU Cc: Michael Ellerman Cc: Andrew Morton Cc: Daniel Axtens Cc: Frederic Weisbecker Cc: Neeraj Upadhyay Cc: Joel Fernandes Cc: Michal Hocko Cc: "Theodore Y . Ts'o" Cc: Oleksiy Avramchenko Cc: stable@vger.kernel.org Reported-by: Paul E. McKenney Reported-by: Sebastian Andrzej Siewior Reported-by: Uladzislau Rezki Acked-by: Paul E. McKenney Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

kprobes: Warn if the kprobe is reregistered

2021-02-09T17:44:32Z

Warn if the kprobe is reregistered, since there must be a software bug (actively used resource must not be re-registered) and caller must be fixed. Link: https://lkml.kernel.org/r/161236436734.194052.4058506306336814476.stgit@devnote2 Acked-by: Naveen N. Rao Acked-by: Ananth N Mavinakayanahalli Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

kretprobe: Avoid re-registration of the same kretprobe earlier

2021-01-29T22:29:16Z

Our system encountered a re-init error when re-registering same kretprobe, where the kretprobe_instance in rp->free_instances is illegally accessed after re-init. Implementation to avoid re-registration has been introduced for kprobe before, but lags for register_kretprobe(). We must check if kprobe has been re-registered before re-initializing kretprobe, otherwise it will destroy the data struct of kretprobe registered, which can lead to memory leak, system crash, also some unexpected behaviors. We use check_kprobe_rereg() to check if kprobe has been re-registered before running register_kretprobe()'s body, for giving a warning message and terminate registration process. Link: https://lkml.kernel.org/r/20210128124427.2031088-1-bobo.shaobowang@huawei.com Cc: stable@vger.kernel.org Fixes: 1f0ab40976460 ("kprobes: Prevent re-registration of the same kprobe") [ The above commit should have been done for kretprobes too ] Acked-by: Naveen N. Rao Acked-by: Ananth N Mavinakayanahalli Acked-by: Masami Hiramatsu Signed-off-by: Wang ShaoBo Signed-off-by: Cheng Jian Signed-off-by: Steven Rostedt (VMware)