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2020-06-16kretprobe: Prevent triggering kretprobe from within kprobe_flush_taskJiri Olsa1-0/+24
Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave. My test was also able to trigger lockdep output: ============================================ WARNING: possible recursive locking detected 5.6.0-rc6+ #6 Not tainted -------------------------------------------- sched-messaging/2767 is trying to acquire lock: ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0 but task is already holding lock: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(kretprobe_table_locks[i].lock)); lock(&(kretprobe_table_locks[i].lock)); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by sched-messaging/2767: #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 stack backtrace: CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6 Call Trace: dump_stack+0x96/0xe0 __lock_acquire.cold.57+0x173/0x2b7 ? native_queued_spin_lock_slowpath+0x42b/0x9e0 ? lockdep_hardirqs_on+0x590/0x590 ? __lock_acquire+0xf63/0x4030 lock_acquire+0x15a/0x3d0 ? kretprobe_hash_lock+0x52/0xa0 _raw_spin_lock_irqsave+0x36/0x70 ? kretprobe_hash_lock+0x52/0xa0 kretprobe_hash_lock+0x52/0xa0 trampoline_handler+0xf8/0x940 ? kprobe_fault_handler+0x380/0x380 ? find_held_lock+0x3a/0x1c0 kretprobe_trampoline+0x25/0x50 ? lock_acquired+0x392/0xbc0 ? _raw_spin_lock_irqsave+0x50/0x70 ? __get_valid_kprobe+0x1f0/0x1f0 ? _raw_spin_unlock_irqrestore+0x3b/0x40 ? finish_task_switch+0x4b9/0x6d0 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 The code within the kretprobe handler checks for probe reentrancy, so we won't trigger any _raw_spin_lock_irqsave probe in there. The problem is in outside kprobe_flush_task, where we call: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave where _raw_spin_lock_irqsave triggers the kretprobe and installs kretprobe_trampoline handler on _raw_spin_lock_irqsave return. The kretprobe_trampoline handler is then executed with already locked kretprobe_table_locks, and first thing it does is to lock kretprobe_table_locks ;-) the whole lockup path like: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed ---> kretprobe_table_locks locked kretprobe_trampoline trampoline_handler kretprobe_hash_lock(current, &head, &flags); <--- deadlock Adding kprobe_busy_begin/end helpers that mark code with fake probe installed to prevent triggering of another kprobe within this code. Using these helpers in kprobe_flush_task, so the probe recursion protection check is hit and the probe is never set to prevent above lockup. Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2 Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking") Cc: Ingo Molnar <mingo@kernel.org> Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16kprobes: Remove redundant arch_disarm_kprobe() callMasami Hiramatsu1-2/+0
Fix to remove redundant arch_disarm_kprobe() call in force_unoptimize_kprobe(). This arch_disarm_kprobe() will be invoked if the kprobe is optimized but disabled, but that means the kprobe (optprobe) is unused (and unoptimized) state. In that case, unoptimize_kprobe() puts it in freeing_list and kprobe_optimizer (do_unoptimize_kprobes()) automatically disarm it. Thus this arch_disarm_kprobe() is redundant. Link: http://lkml.kernel.org/r/158927058719.27680.17183632908465341189.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutexMasami Hiramatsu1-1/+2
In kprobe_optimizer() kick_kprobe_optimizer() is called without kprobe_mutex, but this can race with other caller which is protected by kprobe_mutex. To fix that, expand kprobe_mutex protected area to protect kick_kprobe_optimizer() call. Link: http://lkml.kernel.org/r/158927057586.27680.5036330063955940456.stgit@devnote2 Fixes: cd7ebe2298ff ("kprobes: Use text_poke_smp_batch for optimizing") Cc: Ingo Molnar <mingo@kernel.org> Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ziqian SUN <zsun@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16kprobes: Use non RCU traversal APIs on kprobe_tables if possibleMasami Hiramatsu1-9/+20
Current kprobes uses RCU traversal APIs on kprobe_tables even if it is safe because kprobe_mutex is locked. Make those traversals to non-RCU APIs where the kprobe_mutex is locked. Link: http://lkml.kernel.org/r/158927056452.27680.9710575332163005121.stgit@devnote2 Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16kprobes: Suppress the suspicious RCU warning on kprobesMasami Hiramatsu1-1/+2
Anders reported that the lockdep warns that suspicious RCU list usage in register_kprobe() (detected by CONFIG_PROVE_RCU_LIST.) This is because get_kprobe() access kprobe_table[] by hlist_for_each_entry_rcu() without rcu_read_lock. If we call get_kprobe() from the breakpoint handler context, it is run with preempt disabled, so this is not a problem. But in other cases, instead of rcu_read_lock(), we locks kprobe_mutex so that the kprobe_table[] is not updated. So, current code is safe, but still not good from the view point of RCU. Joel suggested that we can silent that warning by passing lockdep_is_held() to the last argument of hlist_for_each_entry_rcu(). Add lockdep_is_held(&kprobe_mutex) at the end of the hlist_for_each_entry_rcu() to suppress the warning. Link: http://lkml.kernel.org/r/158927055350.27680.10261450713467997503.stgit@devnote2 Reported-by: Anders Roxell <anders.roxell@linaro.org> Suggested-by: Joel Fernandes <joel@joelfernandes.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-04kernel/kprobes.c: convert to use DEFINE_SEQ_ATTRIBUTE macroKefeng Wang1-28/+6
Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/20200509064031.181091-4-wangkefeng.wang@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-1/+1
Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
2020-05-19kprobes: Prevent probes in .noinstr.text sectionThomas Gleixner1-0/+18
Instrumentation is forbidden in the .noinstr.text section. Make kprobes respect this. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lkml.kernel.org/r/20200505134100.179862032@linutronix.de
2020-05-12kprobes: Support NOKPROBE_SYMBOL() in modulesMasami Hiramatsu1-0/+17
Support NOKPROBE_SYMBOL() in modules. NOKPROBE_SYMBOL() records only symbol address in "_kprobe_blacklist" section in the module. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134059.771170126@linutronix.de
2020-05-12kprobes: Support __kprobes blacklist in modulesMasami Hiramatsu1-0/+42
Support __kprobes attribute for blacklist functions in modules. The __kprobes attribute functions are stored in .kprobes.text section. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134059.678201813@linutronix.de
2020-05-12kprobes: Lock kprobe_mutex while showing kprobe_blacklistMasami Hiramatsu1-1/+7
Lock kprobe_mutex while showing kprobe_blacklist to prevent updating the kprobe_blacklist. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134059.571125195@linutronix.de
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig1-1/+1
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-09kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logicMasami Hiramatsu1-24/+43
optimize_kprobe() and unoptimize_kprobe() cancels if a given kprobe is on the optimizing_list or unoptimizing_list already. However, since the following commit: f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") modified the update timing of the KPROBE_FLAG_OPTIMIZED, it doesn't work as expected anymore. The optimized_kprobe could be in the following states: - [optimizing]: Before inserting jump instruction op.kp->flags has KPROBE_FLAG_OPTIMIZED and op->list is not empty. - [optimized]: jump inserted op.kp->flags has KPROBE_FLAG_OPTIMIZED and op->list is empty. - [unoptimizing]: Before removing jump instruction (including unused optprobe) op.kp->flags has KPROBE_FLAG_OPTIMIZED and op->list is not empty. - [unoptimized]: jump removed op.kp->flags doesn't have KPROBE_FLAG_OPTIMIZED and op->list is empty. Current code mis-expects [unoptimizing] state doesn't have KPROBE_FLAG_OPTIMIZED, and that can cause incorrect results. To fix this, introduce optprobe_queued_unopt() to distinguish [optimizing] and [unoptimizing] states and fixes the logic in optimize_kprobe() and unoptimize_kprobe(). [ mingo: Cleaned up the changelog and the code a bit. ] Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bristot@redhat.com Fixes: f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") Link: https://lkml.kernel.org/r/157840814418.7181.13478003006386303481.stgit@devnote2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-27kprobes: Set unoptimized flag after unoptimizing codeMasami Hiramatsu1-1/+3
Set the unoptimized flag after confirming the code is completely unoptimized. Without this fix, when a kprobe hits the intermediate modified instruction (the first byte is replaced by an INT3, but later bytes can still be a jump address operand) while unoptimizing, it can return to the middle byte of the modified code, which causes an invalid instruction exception in the kernel. Usually, this is a rare case, but if we put a probe on the function call while text patching, it always causes a kernel panic as below: # echo p text_poke+5 > kprobe_events # echo 1 > events/kprobes/enable # echo 0 > events/kprobes/enable invalid opcode: 0000 [#1] PREEMPT SMP PTI RIP: 0010:text_poke+0x9/0x50 Call Trace: arch_unoptimize_kprobe+0x22/0x28 arch_unoptimize_kprobes+0x39/0x87 kprobe_optimizer+0x6e/0x290 process_one_work+0x2a0/0x610 worker_thread+0x28/0x3d0 ? process_one_work+0x610/0x610 kthread+0x10d/0x130 ? kthread_park+0x80/0x80 ret_from_fork+0x3a/0x50 text_poke() is used for patching the code in optprobes. This can happen even if we blacklist text_poke() and other functions, because there is a small time window during which we show the intermediate code to other CPUs. [ mingo: Edited the changelog. ] Tested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bristot@redhat.com Fixes: 6274de4984a6 ("kprobes: Support delayed unoptimizing") Link: https://lkml.kernel.org/r/157483422375.25881.13508326028469515760.stgit@devnote2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-20Merge tag 'trace-v5.4' of ↵Linus Torvalds1-16/+40
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Addition of multiprobes to kprobe and uprobe events (allows for more than one probe attached to the same location) - Addition of adding immediates to probe parameters - Clean up of the recordmcount.c code. This brings us closer to merging recordmcount into objtool, and reuse code. - Other small clean ups * tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) selftests/ftrace: Update kprobe event error testcase tracing/probe: Reject exactly same probe event tracing/probe: Fix to allow user to enable events on unloaded modules selftests/ftrace: Select an existing function in kprobe_eventname test tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink() tracing: Make sure variable reference alias has correct var_ref_idx tracing: Be more clever when dumping hex in __print_hex() ftrace: Simplify ftrace hash lookup code in clear_func_from_hash() tracing: Add "gfp_t" support in synthetic_events tracing: Rename tracing_reset() to tracing_reset_cpu() tracing: Document the stack trace algorithm in the comments tracing/arm64: Have max stack tracer handle the case of return address after data recordmcount: Clarify what cleanup() does recordmcount: Remove redundant cleanup() calls recordmcount: Kernel style formatting recordmcount: Kernel style function signature formatting recordmcount: Rewrite error/success handling selftests/ftrace: Add syntax error test for multiprobe selftests/ftrace: Add syntax error test for immediates selftests/ftrace: Add a testcase for kprobe multiprobe event ...
2019-09-16Merge branch 'sched-core-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann, Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers. As perf and the scheduler is getting bigger and more complex, document the status quo of current responsibilities and interests, and spread the review pain^H^H^H^H fun via an increase in the Cc: linecount generated by scripts/get_maintainer.pl. :-) - Add another series of patches that brings the -rt (PREEMPT_RT) tree closer to mainline: split the monolithic CONFIG_PREEMPT dependencies into a new CONFIG_PREEMPTION category that will allow the eventual introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches to go though. - Extend the CPU cgroup controller with uclamp.min and uclamp.max to allow the finer shaping of CPU bandwidth usage. - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS). - Improve the behavior of high CPU count, high thread count applications running under cpu.cfs_quota_us constraints. - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present. - Improve CPU isolation housekeeping CPU allocation NUMA locality. - Fix deadline scheduler bandwidth calculations and logic when cpusets rebuilds the topology, or when it gets deadline-throttled while it's being offlined. - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from setscheduler() system calls without creating global serialization. Add new synchronization between cpuset topology-changing events and the deadline acceptance tests in setscheduler(), which were broken before. - Rework the active_mm state machine to be less confusing and more optimal. - Rework (simplify) the pick_next_task() slowpath. - Improve load-balancing on AMD EPYC systems. - ... and misc cleanups, smaller fixes and improvements - please see the Git log for more details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) sched/psi: Correct overly pessimistic size calculation sched/fair: Speed-up energy-aware wake-ups sched/uclamp: Always use 'enum uclamp_id' for clamp_id values sched/uclamp: Update CPU's refcount on TG's clamp changes sched/uclamp: Use TG's clamps to restrict TASK's clamps sched/uclamp: Propagate system defaults to the root group sched/uclamp: Propagate parent clamps sched/uclamp: Extend CPU's cgroup controller sched/topology: Improve load balancing on AMD EPYC systems arch, ia64: Make NUMA select SMP sched, perf: MAINTAINERS update, add submaintainers and reviewers sched/fair: Use rq_lock/unlock in online_fair_sched_group cpufreq: schedutil: fix equation in comment sched: Rework pick_next_task() slow-path sched: Allow put_prev_task() to drop rq->lock sched/fair: Expose newidle_balance() sched: Add task_struct pointer to sched_class::set_curr_task sched: Rework CPU hotplug task selection sched/{rt,deadline}: Fix set_next_task vs pick_next_task sched: Fix kerneldoc comment for ia64_set_curr_task ...
2019-09-05kprobes: Prohibit probing on BUG() and WARN() addressMasami Hiramatsu1-1/+2
Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to get the address where the BUG() has occurred, kprobes can not do single-step out-of-line that instruction. So prohibit probing on such address. Without this fix, if someone put a kprobe on WARN(), the kernel will crash with invalid opcode error instead of outputing warning message, because kernel can not find correct bug address. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-31kprobes: Allow kprobes coexist with livepatchMasami Hiramatsu1-16/+40
Allow kprobes which do not modify regs->ip, coexist with livepatch by dropping FTRACE_OPS_FL_IPMODIFY from ftrace_ops. User who wants to modify regs->ip (e.g. function fault injection) must set a dummy post_handler to its kprobes when registering. However, if such regs->ip modifying kprobes is set on a function, that function can not be livepatched. Link: http://lkml.kernel.org/r/156403587671.30117.5233558741694155985.stgit@devnote2 Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-19kprobes: Fix potential deadlock in kprobe_optimizer()Andrea Righi1-4/+4
lockdep reports the following deadlock scenario: WARNING: possible circular locking dependency detected kworker/1:1/48 is trying to acquire lock: 000000008d7a62b2 (text_mutex){+.+.}, at: kprobe_optimizer+0x163/0x290 but task is already holding lock: 00000000850b5e2d (module_mutex){+.+.}, at: kprobe_optimizer+0x31/0x290 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (module_mutex){+.+.}: __mutex_lock+0xac/0x9f0 mutex_lock_nested+0x1b/0x20 set_all_modules_text_rw+0x22/0x90 ftrace_arch_code_modify_prepare+0x1c/0x20 ftrace_run_update_code+0xe/0x30 ftrace_startup_enable+0x2e/0x50 ftrace_startup+0xa7/0x100 register_ftrace_function+0x27/0x70 arm_kprobe+0xb3/0x130 enable_kprobe+0x83/0xa0 enable_trace_kprobe.part.0+0x2e/0x80 kprobe_register+0x6f/0xc0 perf_trace_event_init+0x16b/0x270 perf_kprobe_init+0xa7/0xe0 perf_kprobe_event_init+0x3e/0x70 perf_try_init_event+0x4a/0x140 perf_event_alloc+0x93a/0xde0 __do_sys_perf_event_open+0x19f/0xf30 __x64_sys_perf_event_open+0x20/0x30 do_syscall_64+0x65/0x1d0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (text_mutex){+.+.}: __lock_acquire+0xfcb/0x1b60 lock_acquire+0xca/0x1d0 __mutex_lock+0xac/0x9f0 mutex_lock_nested+0x1b/0x20 kprobe_optimizer+0x163/0x290 process_one_work+0x22b/0x560 worker_thread+0x50/0x3c0 kthread+0x112/0x150 ret_from_fork+0x3a/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(module_mutex); lock(text_mutex); lock(module_mutex); lock(text_mutex); *** DEADLOCK *** As a reproducer I've been using bcc's funccount.py (https://github.com/iovisor/bcc/blob/master/tools/funccount.py), for example: # ./funccount.py '*interrupt*' That immediately triggers the lockdep splat. Fix by acquiring text_mutex before module_mutex in kprobe_optimizer(). Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d5b844a2cf50 ("ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()") Link: http://lkml.kernel.org/r/20190812184302.GA7010@xps-13 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-31kprobes: Use CONFIG_PREEMPTIONThomas Gleixner1-1/+1
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Switch kprobes conditional over to CONFIG_PREEMPTION. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20190726212124.516286187@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-18Merge tag 'trace-v5.3' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The main changes in this release include: - Add user space specific memory reading for kprobes - Allow kprobes to be executed earlier in boot The rest are mostly just various clean ups and small fixes" * tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Make trace_get_fields() global tracing: Let filter_assign_type() detect FILTER_PTR_STRING tracing: Pass type into tracing_generic_entry_update() ftrace/selftest: Test if set_event/ftrace_pid exists before writing ftrace/selftests: Return the skip code when tracing directory not configured in kernel tracing/kprobe: Check registered state using kprobe tracing/probe: Add trace_event_call accesses APIs tracing/probe: Add probe event name and group name accesses APIs tracing/probe: Add trace flag access APIs for trace_probe tracing/probe: Add trace_event_file access APIs for trace_probe tracing/probe: Add trace_event_call register API for trace_probe tracing/probe: Add trace_probe init and free functions tracing/uprobe: Set print format when parsing command tracing/kprobe: Set print format right after parsed command kprobes: Fix to init kprobes in subsys_initcall tracepoint: Use struct_size() in kmalloc() ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS ftrace: Enable trampoline when rec count returns back to one tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline tracing: Make a separate config for trace event self tests ...
2019-07-16kprobes: Fix to init kprobes in subsys_initcallMasami Hiramatsu1-1/+1
Since arm64 kernel initializes breakpoint trap vector in arch_initcall(), initializing kprobe (and run smoke test) in postcore_initcall() causes a kernel panic. To fix this issue, move the kprobe initialization in subsys_initcall() (which is called right afer the arch_initcall). In-kernel kprobe users (ftrace and bpf) are using fs_initcall() which is called after subsys_initcall(), so this shouldn't cause more problem. Link: http://lkml.kernel.org/r/155956708268.12228.10363800793132214198.stgit@devnote2 Link: http://lkml.kernel.org/r/20190709153755.GB10123@lakrids.cambridge.arm.com Reported-by: Anders Roxell <anders.roxell@linaro.org> Fixes: b5f8b32c93b2 ("kprobes: Initialize kprobes at postcore_initcall") Tested-by: Anders Roxell <anders.roxell@linaro.org> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-03kprobes: no need to check return value of debugfs_create functionsGreg Kroah-Hartman1-19/+6
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-25kprobes: Initialize kprobes at postcore_initcallMasami Hiramatsu1-2/+1
Initialize kprobes at postcore_initcall level instead of module_init since kprobes is not a module, and it depends on only subsystems initialized in core_initcall. This will allow ftrace kprobe event to add new events when it is initializing because ftrace kprobe event is initialized at later initcall level. Link: http://lkml.kernel.org/r/155851394736.15728.13626739508905120098.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-16kprobes: Fix error check when reusing optimized probesMasami Hiramatsu1-4/+2
The following commit introduced a bug in one of our error paths: 819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()") it missed to handle the return value of kprobe_optready() as error-value. In reality, the kprobe_optready() returns a bool result, so "true" case must be passed instead of 0. This causes some errors on kprobe boot-time selftests on ARM: [ ] Beginning kprobe tests... [ ] Probe ARM code [ ] kprobe [ ] kretprobe [ ] ARM instruction simulation [ ] Check decoding tables [ ] Run test cases [ ] FAIL: test_case_handler not run [ ] FAIL: Test andge r10, r11, r14, asr r7 [ ] FAIL: Scenario 11 ... [ ] FAIL: Scenario 7 [ ] Total instruction simulation tests=1631, pass=1433 fail=198 [ ] kprobe tests failed This can happen if an optimized probe is unregistered and next kprobe is registered on same address until the previous probe is not reclaimed. If this happens, a hidden aggregated probe may be kept in memory, and no new kprobe can probe same address. Also, in that case register_kprobe() will return "1" instead of minus error value, which can mislead caller logic. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org # v5.0+ Fixes: 819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()") Link: http://lkml.kernel.org/r/155530808559.32517.539898325433642204.stgit@devnote2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-13kprobes: Search non-suffixed symbol in blacklistMasami Hiramatsu1-1/+20
Newer GCC versions can generate some different instances of a function with suffixed symbols if the function is optimized and only has a part of that. (e.g. .constprop, .part etc.) In this case, it is not enough to check the entry of kprobe blacklist because it only records non-suffixed symbol address. To fix this issue, search non-suffixed symbol in blacklist if given address is within a symbol which has a suffix. Note that this can cause false positive cases if a kprobe-safe function is optimized to suffixed instance and has same name symbol which is blacklisted. But I would like to chose a fail-safe design for this issue. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrea Righi <righi.andrea@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/154998799234.31052.6136378903570418008.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-26Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-14/+53
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main changes in this cycle on the kernel side: - rework kprobes blacklist handling (Masami Hiramatsu) - misc cleanups on the tooling side these areas were the main focus: - 'perf trace' enhancements (Arnaldo Carvalho de Melo) - 'perf bench' enhancements (Davidlohr Bueso) - 'perf record' enhancements (Alexey Budankov) - 'perf annotate' enhancements (Jin Yao) - 'perf top' enhancements (Jiri Olsa) - Intel hw tracing enhancements (Adrian Hunter) - ARM hw tracing enhancements (Leo Yan, Mathieu Poirier) - ... plus lots of other enhancements, cleanups and fixes" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (171 commits) tools uapi asm: Update asm-generic/unistd.h copy perf symbols: Relax checks on perf-PID.map ownership perf trace: Wire up the fadvise 'advice' table generator perf beauty: Add generator for fadvise64's 'advice' arg constants tools headers uapi: Grab a copy of fadvise.h perf beauty mmap: Print mmap's 'offset' arg in hexadecimal perf beauty mmap: Print PROT_READ before PROT_EXEC to match strace output perf trace beauty: Beautify arch_prctl()'s arguments perf trace: When showing string prefixes show prefix + ??? for unknown entries perf trace: Move strarrays to beauty.h for further reuse perf beauty: Wire up the x86_arch prctl code table generator perf beauty: Add a string table generator for x86's 'arch_prctl' codes tools include arch: Grab a copy of x86's prctl.h perf trace: Show NULL when syscall pointer args are 0 perf trace: Enclose the errno strings with () perf augmented_raw_syscalls: Copy 'access' arg as well perf trace: Add alignment spaces after the closing parens perf trace beauty: Print O_RDONLY when (flags & O_ACCMODE) == 0 perf trace: Allow asking for not suppressing common string prefixes perf trace: Add a prefix member to the strarray class ...
2018-12-17kprobes: Blacklist symbols in arch-defined prohibited areaMasami Hiramatsu1-14/+53
Blacklist symbols in arch-defined probe-prohibited areas. With this change, user can see all symbols which are prohibited to probe in debugfs. All archtectures which have custom prohibit areas should define its own arch_populate_kprobe_blacklist() function, but unless that, all symbols marked __kprobes are blacklisted. Reported-by: Andrea Righi <righi.andrea@gmail.com> Tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yonghong Song <yhs@fb.com> Link: http://lkml.kernel.org/r/154503485491.26176.15823229545155174796.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-27kprobes: Replace synchronize_sched() with synchronize_rcu()Paul E. McKenney1-5/+5
Now that synchronize_rcu() waits for preempt-disable regions of code as well as RCU read-side critical sections, synchronize_sched() can be replaced by synchronize_rcu(). This commit therefore makes this change. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
2018-09-12kprobes: Don't call BUG_ON() if there is a kprobe in use on free listMasami Hiramatsu1-1/+7
Instead of calling BUG_ON(), if we find a kprobe in use on free kprobe list, just remove it from the list and keep it on kprobe hash list as same as other in-use kprobes. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/153666126882.21306.10738207224288507996.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-12kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()Masami Hiramatsu1-7/+20
Make reuse_unused_kprobe() to return error code if it fails to reuse unused kprobe for optprobe instead of calling BUG_ON(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/153666124040.21306.14150398706331307654.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-12kprobes: Remove pointless BUG_ON() from reuse_unused_kprobe()Masami Hiramatsu1-1/+0
Since reuse_unused_kprobe() is called when the given kprobe is unused, checking it inside again with BUG_ON() is pointless. Remove it. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/153666121154.21306.17540752948574483565.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-12kprobes: Remove pointless BUG_ON() from add_new_kprobe()Masami Hiramatsu1-2/+0
Before calling add_new_kprobe(), aggr_probe's GONE flag and kprobe GONE flag are cleared. We don't need to worry about that flag at this point. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/153666118298.21306.4915366706875652652.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-12kprobes: Remove pointless BUG_ON() from disarming processMasami Hiramatsu1-1/+0
All aggr_probes at this line are already disarmed by disable_kprobe() or checked by kprobe_disarmed(). So this BUG_ON() is pointless, remove it. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/153666115463.21306.8799008438116029806.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21kprobes: Replace %p with other pointer typesMasami Hiramatsu1-12/+10
Replace %p with %pS or just remove it if unneeded. And use WARN_ONCE() if it is a single bug. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Howells <dhowells@redhat.com> Cc: David S . Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Tobin C . Harding <me@tobin.cc> Cc: Will Deacon <will.deacon@arm.com> Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491899284.9916.5350534544808158621.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21kprobes: Show address of kprobes if kallsyms doesMasami Hiramatsu1-5/+9
Show probed address in debugfs kprobe list file as same as kallsyms does. This information is used for checking kprobes are placed in the expected address. So it should be able to compared with address in kallsyms. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Howells <dhowells@redhat.com> Cc: David S . Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Tobin C . Harding <me@tobin.cc> Cc: Will Deacon <will.deacon@arm.com> Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491896256.9916.1583733714492565296.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21kprobes: Show blacklist addresses as same as kallsyms doesMasami Hiramatsu1-2/+10
Show kprobes blacklist addresses under same condition of showing kallsyms addresses. Since there are several name conflict for local symbols, kprobe blacklist needs to show each addresses so that user can identify where is on blacklist by comparing with kallsyms. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Howells <dhowells@redhat.com> Cc: David S . Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Tobin C . Harding <me@tobin.cc> Cc: Will Deacon <will.deacon@arm.com> Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491893217.9916.14760965896164273464.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21kprobes: Make list and blacklist root user read onlyMasami Hiramatsu1-2/+2
Since the blacklist and list files on debugfs indicates a sensitive address information to reader, it should be restricted to the root user. Suggested-by: Thomas Richter <tmricht@linux.ibm.com> Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Howells <dhowells@redhat.com> Cc: David S . Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tobin C . Harding <me@tobin.cc> Cc: Will Deacon <will.deacon@arm.com> Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491890171.9916.5183693615601334087.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21kprobes: Don't check the ->break_handler() in generic kprobes codeMasami Hiramatsu1-34/+5
Don't check the ->break_handler() from the core kprobes code, because it was only used by jprobes which got removed. ( In followup patches we'll remove the remaining calls in low level arch handlers as well and remove the callback altogether. ) Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-arch@vger.kernel.org Link: https://lore.kernel.org/lkml/152942462686.15209.6324404940493598980.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21kprobes: Remove jprobe API implementationMasami Hiramatsu1-77/+1
Remove functionally empty jprobe API implementations and test cases. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-arch@vger.kernel.org Link: https://lore.kernel.org/lkml/152942430705.15209.2307050500995264322.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-25kprobes: Fix random address output of blacklist fileThomas Richter1-1/+1
File /sys/kernel/debug/kprobes/blacklist displays random addresses: [root@s8360046 linux]# cat /sys/kernel/debug/kprobes/blacklist 0x0000000047149a90-0x00000000bfcb099a print_type_x8 .... This breaks 'perf probe' which uses the blacklist file to prohibit probes on certain functions by checking the address range. Fix this by printing the correct (unhashed) address. The file mode is read all but this is not an issue as the file hierarchy points out: # ls -ld /sys/ /sys/kernel/ /sys/kernel/debug/ /sys/kernel/debug/kprobes/ /sys/kernel/debug/kprobes/blacklist dr-xr-xr-x 12 root root 0 Apr 19 07:56 /sys/ drwxr-xr-x 8 root root 0 Apr 19 07:56 /sys/kernel/ drwx------ 16 root root 0 Apr 19 06:56 /sys/kernel/debug/ drwxr-xr-x 2 root root 0 Apr 19 06:56 /sys/kernel/debug/kprobes/ -r--r--r-- 1 root root 0 Apr 19 06:56 /sys/kernel/debug/kprobes/blacklist Everything in and below /sys/kernel/debug is rwx to root only, no group or others have access. Background: Directory /sys/kernel/debug/kprobes is created by debugfs_create_dir() which sets the mode bits to rwxr-xr-x. Maybe change that to use the parent's directory mode bits instead? Link: http://lkml.kernel.org/r/20180419105556.86664-1-tmricht@linux.ibm.com Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: stable@vger.kernel.org Cc: <stable@vger.kernel.org> # v4.15+ Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S Miller <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: acme@kernel.org Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-02-16kprobes: Propagate error from disarm_kprobe_ftrace()Jessica Yu1-25/+53
Improve error handling when disarming ftrace-based kprobes. Like with arm_kprobe_ftrace(), propagate any errors from disarm_kprobe_ftrace() so that we do not disable/unregister kprobes that are still armed. In other words, unregister_kprobe() and disable_kprobe() should not report success if the kprobe could not be disarmed. disarm_all_kprobes() keeps its current behavior and attempts to disarm all kprobes. It returns the last encountered error and gives a warning if not all probes could be disarmed. This patch is based on Petr Mladek's original patchset (patches 2 and 3) back in 2015, which improved kprobes error handling, found here: https://lkml.org/lkml/2015/2/26/452 However, further work on this had been paused since then and the patches were not upstreamed. Based-on-patches-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/20180109235124.30886-3-jeyu@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-16kprobes: Propagate error from arm_kprobe_ftrace()Jessica Yu1-25/+75
Improve error handling when arming ftrace-based kprobes. Specifically, if we fail to arm a ftrace-based kprobe, register_kprobe()/enable_kprobe() should report an error instead of success. Previously, this has lead to confusing situations where register_kprobe() would return 0 indicating success, but the kprobe would not be functional if ftrace registration during the kprobe arming process had failed. We should therefore take any errors returned by ftrace into account and propagate this error so that we do not register/enable kprobes that cannot be armed. This can happen if, for example, register_ftrace_function() finds an IPMODIFY conflict (since kprobe_ftrace_ops has this flag set) and returns an error. Such a conflict is possible since livepatches also set the IPMODIFY flag for their ftrace_ops. arm_all_kprobes() keeps its current behavior and attempts to arm all kprobes. It returns the last encountered error and gives a warning if not all probes could be armed. This patch is based on Petr Mladek's original patchset (patches 2 and 3) back in 2015, which improved kprobes error handling, found here: https://lkml.org/lkml/2015/2/26/452 However, further work on this had been paused since then and the patches were not upstreamed. Based-on-patches-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/20180109235124.30886-2-jeyu@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-20kprobes: Disable the jprobes APIsMasami Hiramatsu1-0/+2
Disable the jprobes APIs and comment out the jprobes API function code. This is in preparation of removing all jprobes related code (including kprobe's break_handler). Nowadays ftrace and other tracing features are mature enough to replace jprobes use-cases. Users can safely use ftrace and perf probe etc. for their use cases. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Ian McDonald <ian.mcdonald@jandi.co.nz> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlad Yasevich <vyasevich@gmail.com> Link: http://lkml.kernel.org/r/150724527741.5014.15465541485637899227.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-20kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT=yMasami Hiramatsu1-6/+8
We want to wait for all potentially preempted kprobes trampoline execution to have completed. This guarantees that any freed trampoline memory is not in use by any task in the system anymore. synchronize_rcu_tasks() gives such a guarantee, so use it. Also, this guarantees to wait for all potentially preempted tasks on the instructions which will be replaced with a jump. Since this becomes a problem only when CONFIG_PREEMPT=y, enable CONFIG_TASKS_RCU=y for synchronize_rcu_tasks() in that case. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/150845661962.5443.17724352636247312231.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-18Revert "kprobes: Warn if optprobe handler tries to change execution path"Naveen N. Rao1-4/+1
This reverts commit: e863d539614641 ("kprobes: Warn if optprobe handler tries to change execution path") On PowerPC, we place a probe at kretprobe_trampoline to catch function returns and with CONFIG_OPTPROBES=y, this probe gets optimized. This works for us due to the way we handle the optprobe as described in commit: 762df10bad6954 ("powerpc/kprobes: Optimize kprobe in kretprobe_trampoline()") With the above commit, we end up with a warning. As such, revert this change. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171017081834.3629-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-28kprobes: Warn if optprobe handler tries to change execution pathMasami Hiramatsu1-1/+4
Warn if optprobe handler tries to change execution path. As described in Documentation/kprobes.txt, with optprobe user handler can not change instruction pointer. In that case user must avoid optimizing the kprobes by setting post_handler or break_handler. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexei Starovoitov <ast@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/150581521955.32348.3615624715034787365.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-28kprobes/x86: Make insn buffer always ROX and use text_poke()Masami Hiramatsu1-1/+1
Make insn buffer always ROX and use text_poke() to write the copied instructions instead of set_memory_*(). This makes instruction buffer stronger against other kernel subsystems because there is no window time to modify the buffer. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/150304463032.17009.14195368040691676813.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-08kprobes: Ensure that jprobe probepoints are at function entryNaveen N. Rao1-2/+6
Similar to commit 90ec5e89e393c ("kretprobes: Ensure probe location is at function entry"), ensure that the jprobe probepoint is at function entry. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a4525af6c5a42df385efa31251246cf7cca73598.1499443367.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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