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2022-03-11tracing: Fix strncpy warning in trace_events_synth.cTom Zanussi
0-day reported the strncpy error below: ../kernel/trace/trace_events_synth.c: In function 'last_cmd_set': ../kernel/trace/trace_events_synth.c:65:9: warning: 'strncpy' specified bound depends on the length o\ f the source argument [-Wstringop-truncation] 65 | strncpy(last_cmd, str, strlen(str) + 1); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../kernel/trace/trace_events_synth.c:65:32: note: length computed here 65 | strncpy(last_cmd, str, strlen(str) + 1); | ^~~~~~~~~~~ There's no reason to use strncpy here, in fact there's no reason to do anything but a simple kstrdup() (note we don't even need to check for failure since last_cmod is expected to be either the last cmd string or NULL, and the containing function is a void return). Link: https://lkml.kernel.org/r/77deca8cbfd226981b3f1eab203967381e9b5bd9.camel@kernel.org Fixes: 27c888da9867 ("tracing: Remove size restriction on synthetic event cmd error logging") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-11user_events: Prevent dyn_event delete racing with ioctl add/deleteBeau Belgrave
Find user_events always while under the event_mutex and before leaving the lock, add a ref count to the user_event. This ensures that all paths under the event_mutex that check the ref counts will be synchronized. The ioctl add/delete paths are protected by the reg_mutex. However, dyn_event is only protected by the event_mutex. The dyn_event delete path cannot acquire reg_mutex, since that could cause a deadlock between the ioctl delete case acquiring event_mutex after acquiring the reg_mutex. Link: https://lkml.kernel.org/r/20220310001141.1660-1-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-10bpf-lsm: Make bpf_lsm_kernel_read_file() as sleepableRoberto Sassu
Make bpf_lsm_kernel_read_file() as sleepable, so that bpf_ima_inode_hash() or bpf_ima_file_hash() can be called inside the implementation of this hook. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220302111404.193900-8-roberto.sassu@huawei.com
2022-03-10bpf-lsm: Introduce new helper bpf_ima_file_hash()Roberto Sassu
ima_file_hash() has been modified to calculate the measurement of a file on demand, if it has not been already performed by IMA or the measurement is not fresh. For compatibility reasons, ima_inode_hash() remains unchanged. Keep the same approach in eBPF and introduce the new helper bpf_ima_file_hash() to take advantage of the modified behavior of ima_file_hash(). Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220302111404.193900-4-roberto.sassu@huawei.com
2022-03-10Merge tag 'trace-v5.17-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Minor tracing fixes: - Fix unregistering the same event twice. A user could disable the same event that osnoise will disable on unregistering. - Inform RCU of a quiescent state in the osnoise testing thread. - Fix some kerneldoc comments" * tag 'trace-v5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix some W=1 warnings in kernel doc comments tracing/osnoise: Force quiescent states while tracing tracing/osnoise: Do not unregister events twice
2022-03-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
net/dsa/dsa2.c commit afb3cc1a397d ("net: dsa: unlock the rtnl_mutex when dsa_master_setup() fails") commit e83d56537859 ("net: dsa: replay master state events in dsa_tree_{setup,teardown}_master") https://lore.kernel.org/all/20220307101436.7ae87da0@canb.auug.org.au/ drivers/net/ethernet/intel/ice/ice.h commit 97b0129146b1 ("ice: Fix error with handling of bonding MTU") commit 43113ff73453 ("ice: add TTY for GNSS module for E810T device") https://lore.kernel.org/all/20220310112843.3233bcf1@canb.auug.org.au/ drivers/staging/gdm724x/gdm_lte.c commit fc7f750dc9d1 ("staging: gdm724x: fix use after free in gdm_lte_rx()") commit 4bcc4249b4cf ("staging: Use netif_rx().") https://lore.kernel.org/all/20220308111043.1018a59d@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-10tracehook: Remove tracehook.hEric W. Biederman
Now that all of the definitions have moved out of tracehook.h into ptrace.h, sched/signal.h, resume_user_mode.h there is nothing left in tracehook.h so remove it. Update the few files that were depending upon tracehook.h to bring in definitions to use the headers they need directly. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-13-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10resume_user_mode: Move to resume_user_mode.hEric W. Biederman
Move set_notify_resume and tracehook_notify_resume into resume_user_mode.h. While doing that rename tracehook_notify_resume to resume_user_mode_work. Update all of the places that included tracehook.h for these functions to include resume_user_mode.h instead. Update all of the callers of tracehook_notify_resume to call resume_user_mode_work. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-12-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10task_work: Decouple TIF_NOTIFY_SIGNAL and task_workEric W. Biederman
There are a small handful of reasons besides pending signals that the kernel might want to break out of interruptible sleeps. The flag TIF_NOTIFY_SIGNAL and the helpers that set and clear TIF_NOTIFY_SIGNAL provide that the infrastructure for breaking out of interruptible sleeps and entering the return to user space slow path for those cases. Expand tracehook_notify_signal inline in it's callers and remove it, which makes clear that TIF_NOTIFY_SIGNAL and task_work are separate concepts. Update the comment on set_notify_signal to more accurately describe it's purpose. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-9-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10task_work: Call tracehook_notify_signal from get_signal on all architecturesEric W. Biederman
Always handle TIF_NOTIFY_SIGNAL in get_signal. With commit 35d0b389f3b2 ("task_work: unconditionally run task_work from get_signal()") always calling task_work_run all of the work of tracehook_notify_signal is already happening except clearing TIF_NOTIFY_SIGNAL. Factor clear_notify_signal out of tracehook_notify_signal and use it in get_signal so that get_signal only needs one call of task_work_run. To keep the semantics in sync update xfer_to_guest_mode_work (which does not call get_signal) to call tracehook_notify_signal if either _TIF_SIGPENDING or _TIF_NOTIFY_SIGNAL. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-8-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10tracing: Allow custom events to be added to the tracefs directorySteven Rostedt (Google)
Allow custom events to be added to the events directory in the tracefs file system. For example, a module could be installed that attaches to an event and wants to be enabled and disabled via the tracefs file system. It would use trace_add_event_call() to add the event to the tracefs directory, and trace_remove_event_call() to remove it. Make both those functions EXPORT_SYMBOL_GPL(). Link: https://lkml.kernel.org/r/20220303220625.186988045@goodmis.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-10tracing: Fix last_cmd_set() string management in histogram codeSteven Rostedt (Google)
Using strnlen(dest, str, n) is confusing, as the size of dest must be strlen(dest) + n + 1. Even more confusing, using sizeof(string constant) gives you strlen(string constant) + 1 and not just strlen(). These two together made using strncat() with a constant string a bit off in the calculations as we have: len = sizeof(HIST_PREFIX) + strlen(str) + 1; kfree(last_cmd); last_cmd = kzalloc(len, GFP_KERNEL); strcpy(last_cmd, HIST_PREFIX); len -= sizeof(HIST_PREFIX) + 1; strncat(last_cmd, str, len); The above works if we s/sizeof/strlen/ with HIST_PREFIX (which is defined as "hist:", but because sizeof(HIST_PREFIX) is equal to strlen(HIST_PREFIX) + 1, we can drop the +1 in the code. But at least comment that we are doing so. Link: https://lore.kernel.org/all/202203082112.Iu7tvFl4-lkp@intel.com/ Fixes: 9f8e5aee93ed2 ("tracing: Fix allocation of last_cmd in last_cmd_set()") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-10user_events: Fix potential uninitialized pointer while parsing fieldBeau Belgrave
Ensure name is initialized by default to NULL to prevent possible edge cases that could lead to it being left uninitialized. Add an explicit check for NULL name to ensure edge boundaries. Link: https://lore.kernel.org/bpf/20220224105334.GA2248@kili/ Link: https://lore.kernel.org/linux-trace-devel/20220224181637.2129-1-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-10bpf: Use offsetofend() to simplify macro definitionYuntao Wang
Use offsetofend() instead of offsetof() + sizeof() to simplify MIN_BPF_LINEINFO_SIZE macro definition. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/bpf/20220310161518.534544-1-ytcoode@gmail.com
2022-03-10task_work: Introduce task_work_pendingEric W. Biederman
Wrap the test of task->task_works in a helper function to make it clear what is being tested. All of the other readers of task->task_work use READ_ONCE and this is even necessary on current as other processes can update task->task_work. So for consistency I have added READ_ONCE into task_work_pending. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-7-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10task_work: Remove unnecessary include from posix_timers.hEric W. Biederman
Break a header file circular dependency by removing the unnecessary include of task_work.h from posix_timers.h. sched.h -> posix-timers.h posix-timers.h -> task_work.h task_work.h -> sched.h Add missing includes of task_work.h to: arch/x86/mm/tlb.c kernel/time/posix-cpu-timers.c Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-6-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10ptrace: Remove tracehook_signal_handlerEric W. Biederman
The two line function tracehook_signal_handler is only called from signal_delivered. Expand it inline in signal_delivered and remove it. Just to make it easier to understand what is going on. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-5-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10ptrace: Remove arch_syscall_{enter,exit}_tracehookEric W. Biederman
These functions are alwasy one-to-one wrappers around ptrace_report_syscall_entry and ptrace_report_syscall_exit. So directly call the functions they are wrapping instead. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.hEric W. Biederman
Rename tracehook_report_syscall_{entry,exit} to ptrace_report_syscall_{entry,exit} and place them in ptrace.h There is no longer any generic tracehook infractructure so make these ptrace specific functions ptrace specific. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-3-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10dma-mapping: benchmark: extract a common header file for map_benchmark ↵Tian Tao
definition kernel/dma/map_benchmark.c and selftests/dma/dma_map_benchmark.c have duplicate map_benchmark definitions, which tends to lead to inconsistent changes to map_benchmark on both sides, extract a common header file to avoid this problem. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Acked-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-03-09bpf: Add "live packet" mode for XDP in BPF_PROG_RUNToke Høiland-Jørgensen
This adds support for running XDP programs through BPF_PROG_RUN in a mode that enables live packet processing of the resulting frames. Previous uses of BPF_PROG_RUN for XDP returned the XDP program return code and the modified packet data to userspace, which is useful for unit testing of XDP programs. The existing BPF_PROG_RUN for XDP allows userspace to set the ingress ifindex and RXQ number as part of the context object being passed to the kernel. This patch reuses that code, but adds a new mode with different semantics, which can be selected with the new BPF_F_TEST_XDP_LIVE_FRAMES flag. When running BPF_PROG_RUN in this mode, the XDP program return codes will be honoured: returning XDP_PASS will result in the frame being injected into the networking stack as if it came from the selected networking interface, while returning XDP_TX and XDP_REDIRECT will result in the frame being transmitted out that interface. XDP_TX is translated into an XDP_REDIRECT operation to the same interface, since the real XDP_TX action is only possible from within the network drivers themselves, not from the process context where BPF_PROG_RUN is executed. Internally, this new mode of operation creates a page pool instance while setting up the test run, and feeds pages from that into the XDP program. The setup cost of this is amortised over the number of repetitions specified by userspace. To support the performance testing use case, we further optimise the setup step so that all pages in the pool are pre-initialised with the packet data, and pre-computed context and xdp_frame objects stored at the start of each page. This makes it possible to entirely avoid touching the page content on each XDP program invocation, and enables sending up to 9 Mpps/core on my test box. Because the data pages are recycled by the page pool, and the test runner doesn't re-initialise them for each run, subsequent invocations of the XDP program will see the packet data in the state it was after the last time it ran on that particular page. This means that an XDP program that modifies the packet before redirecting it has to be careful about which assumptions it makes about the packet content, but that is only an issue for the most naively written programs. Enabling the new flag is only allowed when not setting ctx_out and data_out in the test specification, since using it means frames will be redirected somewhere else, so they can't be returned. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220309105346.100053-2-toke@redhat.com
2022-03-09xfs: don't generate selinux audit messages for capability testingDarrick J. Wong
There are a few places where we test the current process' capability set to decide if we're going to be more or less generous with resource acquisition for a system call. If the process doesn't have the capability, we can continue the call, albeit in a degraded mode. These are /not/ the actual security decisions, so it's not proper to use capable(), which (in certain selinux setups) causes audit messages to get logged. Switch them to has_capability_noaudit. Fixes: 7317a03df703f ("xfs: refactor inode ownership change transaction/inode/quota allocation idiom") Fixes: ea9a46e1c4925 ("xfs: only return detailed fsmap info if the caller has CAP_SYS_ADMIN") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2022-03-09ftrace: Fix some W=1 warnings in kernel doc commentsJiapeng Chong
Clean up the following clang-w1 warning: kernel/trace/ftrace.c:7827: warning: Function parameter or member 'ops' not described in 'unregister_ftrace_function'. kernel/trace/ftrace.c:7805: warning: Function parameter or member 'ops' not described in 'register_ftrace_function'. Link: https://lkml.kernel.org/r/20220307004303.26399-1-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-09tracing/osnoise: Force quiescent states while tracingNicolas Saenz Julienne
At the moment running osnoise on a nohz_full CPU or uncontested FIFO priority and a PREEMPT_RCU kernel might have the side effect of extending grace periods too much. This will entice RCU to force a context switch on the wayward CPU to end the grace period, all while introducing unwarranted noise into the tracer. This behaviour is unavoidable as overly extending grace periods might exhaust the system's memory. This same exact problem is what extended quiescent states (EQS) were created for, conversely, rcu_momentary_dyntick_idle() emulates them by performing a zero duration EQS. So let's make use of it. In the common case rcu_momentary_dyntick_idle() is fairly inexpensive: atomically incrementing a local per-CPU counter and doing a store. So it shouldn't affect osnoise's measurements (which has a 1us granularity), so we'll call it unanimously. The uncommon case involve calling rcu_momentary_dyntick_idle() after having the osnoise process: - Receive an expedited quiescent state IPI with preemption disabled or during an RCU critical section. (activates rdp->cpu_no_qs.b.exp code-path). - Being preempted within in an RCU critical section and having the subsequent outermost rcu_read_unlock() called with interrupts disabled. (t->rcu_read_unlock_special.b.blocked code-path). Neither of those are possible at the moment, and are unlikely to be in the future given the osnoise's loop design. On top of this, the noise generated by the situations described above is unavoidable, and if not exposed by rcu_momentary_dyntick_idle() will be eventually seen in subsequent rcu_read_unlock() calls or schedule operations. Link: https://lkml.kernel.org/r/20220307180740.577607-1-nsaenzju@redhat.com Cc: stable@vger.kernel.org Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-09tracing/osnoise: Do not unregister events twiceDaniel Bristot de Oliveira
Nicolas reported that using: # trace-cmd record -e all -M 10 -p osnoise --poll Resulted in the following kernel warning: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1217 at kernel/tracepoint.c:404 tracepoint_probe_unregister+0x280/0x370 [...] CPU: 0 PID: 1217 Comm: trace-cmd Not tainted 5.17.0-rc6-next-20220307-nico+ #19 RIP: 0010:tracepoint_probe_unregister+0x280/0x370 [...] CR2: 00007ff919b29497 CR3: 0000000109da4005 CR4: 0000000000170ef0 Call Trace: <TASK> osnoise_workload_stop+0x36/0x90 tracing_set_tracer+0x108/0x260 tracing_set_trace_write+0x94/0xd0 ? __check_object_size.part.0+0x10a/0x150 ? selinux_file_permission+0x104/0x150 vfs_write+0xb5/0x290 ksys_write+0x5f/0xe0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7ff919a18127 [...] ---[ end trace 0000000000000000 ]--- The warning complains about an attempt to unregister an unregistered tracepoint. This happens on trace-cmd because it first stops tracing, and then switches the tracer to nop. Which is equivalent to: # cd /sys/kernel/tracing/ # echo osnoise > current_tracer # echo 0 > tracing_on # echo nop > current_tracer The osnoise tracer stops the workload when no trace instance is actually collecting data. This can be caused both by disabling tracing or disabling the tracer itself. To avoid unregistering events twice, use the existing trace_osnoise_callback_enabled variable to check if the events (and the workload) are actually active before trying to deactivate them. Link: https://lore.kernel.org/all/c898d1911f7f9303b7e14726e7cc9678fbfb4a0e.camel@redhat.com/ Link: https://lkml.kernel.org/r/938765e17d5a781c2df429a98f0b2e7cc317b022.1646823913.git.bristot@kernel.org Cc: stable@vger.kernel.org Cc: Marcelo Tosatti <mtosatti@redhat.com> Fixes: 2fac8d6486d5 ("tracing/osnoise: Allow multiple instances of the same tracer") Reported-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-08prlimit: do not grab the tasklist_lockBarret Rhoden
Unnecessarily grabbing the tasklist_lock can be a scalability bottleneck for workloads that also must grab the tasklist_lock for waiting, killing, and cloning. The tasklist_lock was grabbed to protect tsk->sighand from disappearing (becoming NULL). tsk->signal was already protected by holding a reference to tsk. update_rlimit_cpu() assumed tsk->sighand != NULL. With this commit, it attempts to lock_task_sighand(). However, this means that update_rlimit_cpu() can fail. This only happens when a task is exiting. Note that during exec, sighand may *change*, but it will not be NULL. Prior to this commit, the do_prlimit() ensured that update_rlimit_cpu() would not fail by read locking the tasklist_lock and checking tsk->sighand != NULL. If update_rlimit_cpu() fails, there may be other tasks that are not exiting that share tsk->signal. However, the group_leader is the last task to be released, so if we cannot update_rlimit_cpu(group_leader), then the entire process is exiting. The only other caller of update_rlimit_cpu() is selinux_bprm_committing_creds(). It has tsk == current, so update_rlimit_cpu() cannot fail (current->sighand cannot disappear until current exits). This change resulted in a 14% speedup on a microbenchmark where parents kill and wait on their children, and children getpriority, setpriority, and getrlimit. Signed-off-by: Barret Rhoden <brho@google.com> Link: https://lkml.kernel.org/r/20220106172041.522167-4-brho@google.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2022-03-08prlimit: make do_prlimit() staticBarret Rhoden
There are no other callers in the kernel. Fixed up a comment format and whitespace issue when moving do_prlimit() higher in sys.c. Signed-off-by: Barret Rhoden <brho@google.com> Link: https://lkml.kernel.org/r/20220106172041.522167-3-brho@google.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2022-03-08sched/topology: Remove redundant variable and fix incorrect type in ↵K Prateek Nayak
build_sched_domains While investigating the sparse warning reported by the LKP bot [1], observed that we have a redundant variable "top" in the function build_sched_domains that was introduced in the recent commit e496132ebedd ("sched/fair: Adjust the allowed NUMA imbalance when SD_NUMA spans multiple LLCs") The existing variable "sd" suffices which allows us to remove the redundant variable "top" while annotating the other variable "top_p" with the "__rcu" annotation to silence the sparse warning. [1] https://lore.kernel.org/lkml/202202170853.9vofgC3O-lkp@intel.com/ Fixes: e496132ebedd ("sched/fair: Adjust the allowed NUMA imbalance when SD_NUMA spans multiple LLCs") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lore.kernel.org/r/20220218162743.1134-1-kprateek.nayak@amd.com
2022-03-08sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity()Dietmar Eggemann
The `struct rq *rq` parameter isn't used. Remove it. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-7-dietmar.eggemann@arm.com
2022-03-08sched/deadline,rt: Remove unused functions for !CONFIG_SMPDietmar Eggemann
The need_pull_[rt|dl]_task() and pull_[rt|dl]_task() functions are not used on a !CONFIG_SMP system. Remove them. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-6-dietmar.eggemann@arm.com
2022-03-08sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistentlyDietmar Eggemann
Deploy __node_2_pdl(node), __node_2_dle(node) and rb_first_cached() consistently throughout the sched class source file which makes the code at least easier to read. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-5-dietmar.eggemann@arm.com
2022-03-08sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy()Dietmar Eggemann
Both functions are doing almost the same, that is checking if admission control is still respected. With exclusive cpusets, dl_task_can_attach() checks if the destination cpuset (i.e. its root domain) has enough CPU capacity to accommodate the task. dl_cpu_busy() checks if there is enough CPU capacity in the cpuset in case the CPU is hot-plugged out. dl_task_can_attach() is used to check if a task can be admitted while dl_cpu_busy() is used to check if a CPU can be hotplugged out. Make dl_cpu_busy() able to deal with a task and use it instead of dl_task_can_attach() in task_can_attach(). Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-4-dietmar.eggemann@arm.com
2022-03-08sched/deadline: Move bandwidth mgmt and reclaim functions into sched class ↵Dietmar Eggemann
source file Move the deadline bandwidth management (admission control) functions __dl_add(), __dl_sub() and __dl_overflow() as well as the bandwidth reclaim function __dl_update() from private task scheduler header file to the deadline sched class source file. The functions are only used internally so they don't have to be exported. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-3-dietmar.eggemann@arm.com
2022-03-08sched/deadline: Remove unused def_dl_bandwidthDietmar Eggemann
Since commit 1724813d9f2c ("sched/deadline: Remove the sysctl_sched_dl knobs") the default deadline bandwidth control structure has no purpose. Remove it. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-2-dietmar.eggemann@arm.com
2022-03-08bpf: Determine buf_info inside check_buffer_access()Shung-Hsi Yu
Instead of determining buf_info string in the caller of check_buffer_access(), we can determine whether the register type is read-only through type_is_rdonly_mem() helper inside check_buffer_access() and construct buf_info, making the code slightly cleaner. Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/YiWYLnAkEZXBP/gH@syu-laptop
2022-03-07bpf: Remove redundant slashYuntao Wang
The trailing slash of LIBBPF_SRCS is redundant, remove it. Also inline it as its only used in LIBBPF_INCLUDE. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220305161013.361646-1-ytcoode@gmail.com
2022-03-07bpf: Replace strncpy() with strscpy()Yuntao Wang
Using strncpy() on NUL-terminated strings is considered deprecated[1]. Moreover, if the length of 'task->comm' is less than the destination buffer size, strncpy() will NUL-pad the destination buffer, which is a needless performance penalty. Replacing strncpy() with strscpy() fixes all these issues. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220304070408.233658-1-ytcoode@gmail.com
2022-03-07Merge tag 'x86_bugs_for_v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 spectre fixes from Borislav Petkov: - Mitigate Spectre v2-type Branch History Buffer attacks on machines which support eIBRS, i.e., the hardware-assisted speculation restriction after it has been shown that such machines are vulnerable even with the hardware mitigation. - Do not use the default LFENCE-based Spectre v2 mitigation on AMD as it is insufficient to mitigate such attacks. Instead, switch to retpolines on all AMD by default. - Update the docs and add some warnings for the obviously vulnerable cmdline configurations. * tag 'x86_bugs_for_v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT x86/speculation: Warn about Spectre v2 LFENCE mitigation x86/speculation: Update link to AMD speculation whitepaper x86/speculation: Use generic retpoline by default on AMD x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting Documentation/hw-vuln: Update spectre doc x86/speculation: Add eIBRS + Retpoline options x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE
2022-03-07tick/rcu: Stop allowing RCU_SOFTIRQ in idleFrederic Weisbecker
RCU_SOFTIRQ used to be special in that it could be raised on purpose within the idle path to prevent from stopping the tick. Some code still prevents from unnecessary warnings related to this specific behaviour while entering in dynticks-idle mode. However the nohz layout has changed quite a bit in ten years, and the removal of CONFIG_RCU_FAST_NO_HZ has been the final straw to this safe-conduct. Now the RCU_SOFTIRQ vector is expected to be raised from sane places. A remaining corner case is admitted though when the vector is invoked in fragile hotplug path. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Menzel <pmenzel@molgen.mpg.de>
2022-03-07tick/rcu: Remove obsolete rcu_needs_cpu() parametersFrederic Weisbecker
With the removal of CONFIG_RCU_FAST_NO_HZ, the parameters in rcu_needs_cpu() are not necessary anymore. Simply remove them. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Menzel <pmenzel@molgen.mpg.de>
2022-03-07tick: Detect and fix jiffies update stallFrederic Weisbecker
On some rare cases, the timekeeper CPU may be delaying its jiffies update duty for a while. Known causes include: * The timekeeper is waiting on stop_machine in a MULTI_STOP_DISABLE_IRQ or MULTI_STOP_RUN state. Disabled interrupts prevent from timekeeping updates while waiting for the target CPU to complete its stop_machine() callback. * The timekeeper vcpu has VMEXIT'ed for a long while due to some overload on the host. Detect and fix these situations with emergency timekeeping catchups. Original-patch-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2022-03-07swiotlb: rework "fix info leak with DMA_FROM_DEVICE"Halil Pasic
Unfortunately, we ended up merging an old version of the patch "fix info leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph (the swiotlb maintainer), he asked me to create an incremental fix (after I have pointed this out the mix up, and asked him for guidance). So here we go. The main differences between what we got and what was agreed are: * swiotlb_sync_single_for_device is also required to do an extra bounce * We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters * The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE must take precedence over DMA_ATTR_SKIP_CPU_SYNC Thus this patch removes DMA_ATTR_OVERWRITE, and makes swiotlb_sync_single_for_device() bounce unconditionally (that is, also when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale data from the swiotlb buffer. Let me note, that if the size used with dma_sync_* API is less than the size used with dma_[un]map_*, under certain circumstances we may still end up with swiotlb not being transparent. In that sense, this is no perfect fix either. To get this bullet proof, we would have to bounce the entire mapping/bounce buffer. For that we would have to figure out the starting address, and the size of the mapping in swiotlb_sync_single_for_device(). While this does seem possible, there seems to be no firm consensus on how things are supposed to work. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Fixes: ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-07Merge branch 'clocksource.2022.02.01b' of ↵Thomas Gleixner
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into timers/core Pull clocksource watchdog update from Paul McKenney: - Add a config option for the maximum skew of the watchdog. Link: https://lore.kernel.org/r/20220224000718.GA3747431@paulmck-ThinkPad-P17-Gen-1
2022-03-07Merge branch 'topic/func-desc-lkdtm' into nextMichael Ellerman
Merge a topic branch we are maintaining with some cross-architecture changes to function descriptor handling and their use in LKDTM. From Christophe's cover letter: Fix LKDTM for PPC64/IA64/PARISC PPC64/IA64/PARISC have function descriptors. LKDTM doesn't work on those three architectures because LKDTM messes up function descriptors with functions. This series does some cleanup in the three architectures and refactors function descriptors so that it can then easily use it in a generic way in LKDTM.
2022-03-06Merge tag 'trace-v5.17-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Fix sorting on old "cpu" value in histograms - Fix return value of __setup() boot parameter handlers * tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix return value of __setup handlers tracing/histogram: Fix sorting on old "cpu" value
2022-03-05bpf: Reject programs that try to load __percpu memory.Hao Luo
With the introduction of the btf_type_tag "percpu", we can add a MEM_PERCPU to identify those pointers that point to percpu memory. The ability of differetiating percpu pointers from regular memory pointers have two benefits: 1. It forbids unexpected use of percpu pointers, such as direct loads. In kernel, there are special functions used for accessing percpu memory. Directly loading percpu memory is meaningless. We already have BPF helpers like bpf_per_cpu_ptr() and bpf_this_cpu_ptr() that wrap the kernel percpu functions. So we can now convert percpu pointers into regular pointers in a safe way. 2. Previously, bpf_per_cpu_ptr() and bpf_this_cpu_ptr() only work on PTR_TO_PERCPU_BTF_ID, a special reg_type which describes static percpu variables in kernel (we rely on pahole to encode them into vmlinux BTF). Now, since we can identify __percpu tagged pointers, we can also identify dynamically allocated percpu memory as well. It means we can use bpf_xxx_cpu_ptr() on dynamic percpu memory. This would be very convenient when accessing fields like "cgroup->rstat_cpu". Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220304191657.981240-4-haoluo@google.com
2022-03-05bpf: Fix checking PTR_TO_BTF_ID in check_mem_accessHao Luo
With the introduction of MEM_USER in commit c6f1bfe89ac9 ("bpf: reject program if a __user tagged memory accessed in kernel way") PTR_TO_BTF_ID can be combined with a MEM_USER tag. Therefore, most likely, when we compare reg_type against PTR_TO_BTF_ID, we want to use the reg's base_type. Previously the check in check_mem_access() wants to say: if the reg is BTF_ID but not NULL, the execution flow falls into the 'then' branch. But now a reg of (BTF_ID | MEM_USER), which should go into the 'then' branch, goes into the 'else'. The end results before and after this patch are the same: regs tagged with MEM_USER get rejected, but not in a way we intended. So fix the condition, the error message now is correct. Before (log from commit 696c39011538): $ ./test_progs -v -n 22/3 ... libbpf: prog 'test_user1': BPF program load failed: Permission denied libbpf: prog 'test_user1': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(test_user1, struct bpf_testmod_btf_type_tag_1 *arg) 0: (79) r1 = *(u64 *)(r1 +0) func 'bpf_testmod_test_btf_type_tag_user_1' arg0 has btf_id 136561 type STRUCT 'bpf_testmod_btf_type_tag_1' 1: R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0) ; g = arg->a; 1: (61) r1 = *(u32 *)(r1 +0) R1 invalid mem access 'user_ptr_' Now: libbpf: prog 'test_user1': BPF program load failed: Permission denied libbpf: prog 'test_user1': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(test_user1, struct bpf_testmod_btf_type_tag_1 *arg) 0: (79) r1 = *(u64 *)(r1 +0) func 'bpf_testmod_test_btf_type_tag_user_1' arg0 has btf_id 104036 type STRUCT 'bpf_testmod_btf_type_tag_1' 1: R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,ref_obj_id=0,off=0,imm=0) ; g = arg->a; 1: (61) r1 = *(u32 *)(r1 +0) R1 is ptr_bpf_testmod_btf_type_tag_1 access user memory: off=0 Note the error message for the reason of rejection. Fixes: c6f1bfe89ac9 ("bpf: reject program if a __user tagged memory accessed in kernel way") Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220304191657.981240-2-haoluo@google.com
2022-03-05bpf: Harden register offset checks for release helpers and kfuncsKumar Kartikeya Dwivedi
Let's ensure that the PTR_TO_BTF_ID reg being passed in to release BPF helpers and kfuncs always has its offset set to 0. While not a real problem now, there's a very real possibility this will become a problem when more and more kfuncs are exposed, and more BPF helpers are added which can release PTR_TO_BTF_ID. Previous commits already protected against non-zero var_off. One of the case we are concerned about now is when we have a type that can be returned by e.g. an acquire kfunc: struct foo { int a; int b; struct bar b; }; ... and struct bar is also a type that can be returned by another acquire kfunc. Then, doing the following sequence: struct foo *f = bpf_get_foo(); // acquire kfunc if (!f) return 0; bpf_put_bar(&f->b); // release kfunc ... would work with the current code, since the btf_struct_ids_match takes reg->off into account for matching pointer type with release kfunc argument type, but would obviously be incorrect, and most likely lead to a kernel crash. A test has been included later to prevent regressions in this area. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220304224645.3677453-5-memxor@gmail.com
2022-03-05bpf: Disallow negative offset in check_ptr_off_regKumar Kartikeya Dwivedi
check_ptr_off_reg only allows fixed offset to be set for PTR_TO_BTF_ID, where reg->off < 0 doesn't make sense. This would shift the pointer backwards, and fails later in btf_struct_ids_match or btf_struct_walk due to out of bounds access (since offset is interpreted as unsigned). Improve the verifier by rejecting this case by using a better error message for BPF helpers and kfunc, by putting a check inside the check_func_arg_reg_off function. Also, update existing verifier selftests to work with new error string. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220304224645.3677453-4-memxor@gmail.com
2022-03-05bpf: Fix PTR_TO_BTF_ID var_off checkKumar Kartikeya Dwivedi
When kfunc support was added, check_ctx_reg was called for PTR_TO_CTX register, but no offset checks were made for PTR_TO_BTF_ID. Only reg->off was taken into account by btf_struct_ids_match, which protected against type mismatch due to non-zero reg->off, but when reg->off was zero, a user could set the variable offset of the register and allow it to be passed to kfunc, leading to bad pointer being passed into the kernel. Fix this by reusing the extracted helper check_func_arg_reg_off from previous commit, and make one call before checking all supported register types. Since the list is maintained, any future changes will be taken into account by updating check_func_arg_reg_off. This function prevents non-zero var_off to be set for PTR_TO_BTF_ID, but still allows a fixed non-zero reg->off, which is needed for type matching to work correctly when using pointer arithmetic. ARG_DONTCARE is passed as arg_type, since kfunc doesn't support accepting a ARG_PTR_TO_ALLOC_MEM without relying on size of parameter type from BTF (in case of pointer), or using a mem, len pair. The forcing of offset check for ARG_PTR_TO_ALLOC_MEM is done because ringbuf helpers obtain the size from the header located at the beginning of the memory region, hence any changes to the original pointer shouldn't be allowed. In case of kfunc, size is always known, either at verification time, or using the length parameter, hence this forcing is not required. Since this check will happen once already for PTR_TO_CTX, remove the check_ptr_off_reg call inside its block. Fixes: e6ac2450d6de ("bpf: Support bpf program calling kernel function") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220304224645.3677453-3-memxor@gmail.com