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2020-07-22Merge branch 'sched/urgent'Peter Zijlstra
2020-07-22sched: Fix race against ptrace_freeze_trace()Peter Zijlstra
There is apparently one site that violates the rule that only current and ttwu() will modify task->state, namely ptrace_{,un}freeze_traced() will change task->state for a remote task. Oleg explains: "TASK_TRACED/TASK_STOPPED was always protected by siglock. In particular, ttwu(__TASK_TRACED) must be always called with siglock held. That is why ptrace_freeze_traced() assumes it can safely do s/TASK_TRACED/__TASK_TRACED/ under spin_lock(siglock)." This breaks the ordering scheme introduced by commit: dbfb089d360b ("sched: Fix loadavg accounting race") Specifically, the reload not matching no longer implies we don't have to block. Simply things by noting that what we need is a LOAD->STORE ordering and this can be provided by a control dependency. So replace: prev_state = prev->state; raw_spin_lock(&rq->lock); smp_mb__after_spinlock(); /* SMP-MB */ if (... && prev_state && prev_state == prev->state) deactivate_task(); with: prev_state = prev->state; if (... && prev_state) /* CTRL-DEP */ deactivate_task(); Since that already implies the 'prev->state' load must be complete before allowing the 'prev->on_rq = 0' store to become visible. Fixes: dbfb089d360b ("sched: Fix loadavg accounting race") Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com> Tested-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-21bpf: net: Use precomputed btf_id for bpf iteratorsYonghong Song
One additional field btf_id is added to struct bpf_ctx_arg_aux to store the precomputed btf_ids. The btf_id is computed at build time with BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions. All existing bpf iterators are changed to used pre-compute btf_ids. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
2020-07-21bpf: Compute bpf_skc_to_*() helper socket btf ids at build timeYonghong Song
Currently, socket types (struct tcp_sock, udp_sock, etc.) used by bpf_skc_to_*() helpers are computed when vmlinux_btf is first built in the kernel. Commit 5a2798ab32ba ("bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros") implemented a mechanism to compute btf_ids at kernel build time which can simplify kernel implementation and reduce runtime overhead by removing in-kernel btf_id calculation. This patch did exactly this, removing in-kernel btf_id computation and utilizing build-time btf_id computation. If CONFIG_DEBUG_INFO_BTF is not defined, BTF_ID_LIST will define an array with size of 5, which is not enough for btf_sock_ids. So define its own static array if CONFIG_DEBUG_INFO_BTF is not defined. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163358.1393023-1-yhs@fb.com
2020-07-21bpf: cpumap: Fix possible rcpu kthread hungLorenzo Bianconi
Fix the following cpumap kthread hung. The issue is currently occurring when __cpu_map_load_bpf_program fails (e.g if the bpf prog has not BPF_XDP_CPUMAP as expected_attach_type) $./test_progs -n 101 101/1 cpumap_with_progs:OK 101 xdp_cpumap_attach:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED [ 369.996478] INFO: task cpumap/0/map:7:205 blocked for more than 122 seconds. [ 369.998463] Not tainted 5.8.0-rc4-01472-ge57892f50a07 #212 [ 370.000102] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.001918] cpumap/0/map:7 D 0 205 2 0x00004000 [ 370.003228] Call Trace: [ 370.003930] __schedule+0x5c7/0xf50 [ 370.004901] ? io_schedule_timeout+0xb0/0xb0 [ 370.005934] ? static_obj+0x31/0x80 [ 370.006788] ? mark_held_locks+0x24/0x90 [ 370.007752] ? cpu_map_bpf_prog_run_xdp+0x6c0/0x6c0 [ 370.008930] schedule+0x6f/0x160 [ 370.009728] schedule_preempt_disabled+0x14/0x20 [ 370.010829] kthread+0x17b/0x240 [ 370.011433] ? kthread_create_worker_on_cpu+0xd0/0xd0 [ 370.011944] ret_from_fork+0x1f/0x30 [ 370.012348] Showing all locks held in the system: [ 370.013025] 1 lock held by khungtaskd/33: [ 370.013432] #0: ffffffff82b24720 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x28/0x1c3 [ 370.014461] ============================================= Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") Reported-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/e54f2aabf959f298939e5507b09c48f8c2e380be.1595170625.git.lorenzo@kernel.org
2020-07-21bpf, netns: Fix build without CONFIG_INETJakub Sitnicki
When CONFIG_NET is set but CONFIG_INET isn't, build fails with: ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_unneed': kernel/bpf/net_namespace.c:32: undefined reference to `bpf_sk_lookup_enabled' ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_need': kernel/bpf/net_namespace.c:43: undefined reference to `bpf_sk_lookup_enabled' This is because without CONFIG_INET bpf_sk_lookup_enabled symbol is not available. Wrap references to bpf_sk_lookup_enabled with preprocessor conditionals. Fixes: 1559b4aa1db4 ("inet: Run SK_LOOKUP BPF program on socket lookup") Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Link: https://lore.kernel.org/bpf/20200721100716.720477-1-jakub@cloudflare.com
2020-07-21audit: report audit wait metric in audit status replyMax Englander
In environments where the preservation of audit events and predictable usage of system memory are prioritized, admins may use a combination of --backlog_wait_time and -b options at the risk of degraded performance resulting from backlog waiting. In some cases, this risk may be preferred to lost events or unbounded memory usage. Ideally, this risk can be mitigated by making adjustments when backlog waiting is detected. However, detection can be difficult using the currently available metrics. For example, an admin attempting to debug degraded performance may falsely believe a full backlog indicates backlog waiting. It may turn out the backlog frequently fills up but drains quickly. To make it easier to reliably track degraded performance to backlog waiting, this patch makes the following changes: Add a new field backlog_wait_time_total to the audit status reply. Initialize this field to zero. Add to this field the total time spent by the current task on scheduled timeouts while the backlog limit is exceeded. Reset field to zero upon request via AUDIT_SET. Tested on Ubuntu 18.04 using complementary changes to the audit-userspace and audit-testsuite: - https://github.com/linux-audit/audit-userspace/pull/134 - https://github.com/linux-audit/audit-testsuite/pull/97 Signed-off-by: Max Englander <max.englander@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-21audit: purge audit_log_string from the intra-kernel audit APIRichard Guy Briggs
audit_log_string() was inteded to be an internal audit function and since there are only two internal uses, remove them. Purge all external uses of it by restructuring code to use an existing audit_log_format() or using audit_log_format(). Please see the upstream issue https://github.com/linux-audit/audit-kernel/issues/84 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-21exec: Implement kernel_execveEric W. Biederman
To allow the kernel not to play games with set_fs to call exec implement kernel_execve. The function kernel_execve takes pointers into kernel memory and copies the values pointed to onto the new userspace stack. The calls with arguments from kernel space of do_execve are replaced with calls to kernel_execve. The calls do_execve and do_execveat are made static as there are now no callers outside of exec. The comments that mention do_execve are updated to refer to kernel_execve or execve depending on the circumstances. In addition to correcting the comments, this makes it easy to grep for do_execve and verify it is not used. Inspired-by: https://lkml.kernel.org/r/20200627072704.2447163-1-hch@lst.de Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/87wo365ikj.fsf@x220.int.ebiederm.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-20ima: Support additional conditionals in the KEXEC_CMDLINE hook functionTyler Hicks
Take the properties of the kexec kernel's inode and the current task ownership into consideration when matching a KEXEC_CMDLINE operation to the rules in the IMA policy. This allows for some uniformity when writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK, and KEXEC_CMDLINE operations. Prior to this patch, it was not possible to write a set of rules like this: dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t dont_measure func=KEXEC_CMDLINE obj_type=foo_t measure func=KEXEC_KERNEL_CHECK measure func=KEXEC_INITRAMFS_CHECK measure func=KEXEC_CMDLINE The inode information associated with the kernel being loaded by a kexec_kernel_load(2) syscall can now be included in the decision to measure or not Additonally, the uid, euid, and subj_* conditionals can also now be used in KEXEC_CMDLINE rules. There was no technical reason as to why those conditionals weren't being considered previously other than ima_match_rules() didn't have a valid inode to use so it immediately bailed out for KEXEC_CMDLINE operations rather than going through the full list of conditional comparisons. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: kexec@lists.infradead.org Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20time/sched_clock: Use raw_read_seqcount_latch()Ahmed S. Darwish
sched_clock uses seqcount_t latching to switch between two storage places protected by the sequence counter. This allows it to have interruptible, NMI-safe, seqcount_t write side critical sections. Since 7fc26327b756 ("seqlock: Introduce raw_read_seqcount_latch()"), raw_read_seqcount_latch() became the standardized way for seqcount_t latch read paths. Due to the dependent load, it also has one read memory barrier less than the currently used raw_read_seqcount() API. Use raw_read_seqcount_latch() for the seqcount_t latch read path. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Leo Yan <leo.yan@linaro.org> Link: https://lkml.kernel.org/r/20200625085745.GD117543@hirez.programming.kicks-ass.net Link: https://lkml.kernel.org/r/20200715092345.GA231464@debian-buster-darwi.lab.linutronix.de Link: https://lore.kernel.org/r/20200716051130.4359-3-leo.yan@linaro.org References: 1809bfa44e10 ("timers, sched/clock: Avoid deadlock during read from NMI") Signed-off-by: Will Deacon <will@kernel.org>
2020-07-20sched_clock: Expose struct clock_read_dataPeter Zijlstra
In order to support perf_event_mmap_page::cap_time features, an architecture needs, aside from a userspace readable counter register, to expose the exact clock data so that userspace can convert the counter register into a correct timestamp. Provide struct clock_read_data and two (seqcount) helpers so that architectures (arm64 in specific) can expose the numbers to userspace. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Link: https://lore.kernel.org/r/20200716051130.4359-2-leo.yan@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-07-19Merge tag 'timers-urgent-2020-07-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull timer fixes from Thomas Gleixner: "Two fixes for the timer wheel: - A timer which is already expired at enqueue time can set the base->next_expiry value backwards. As a consequence base->clk can be set back as well. This can lead to timers expiring early. Add a sanity check to prevent this. - When a timer is queued with an expiry time beyond the wheel capacity then it should be queued in the bucket of the last wheel level which is expiring last. The code adjusted the expiry time to the maximum wheel capacity, which is only correct when the wheel clock is 0. Aside of that the check whether the delta is larger than wheel capacity does not check the delta, it checks the expiry value itself. As a result timers can expire at random. Fix this by checking the right variable and adjust expiry time so it becomes base->clock plus capacity which places it into the outmost bucket in the last wheel level" * tag 'timers-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timer: Fix wheel index calculation on last level timer: Prevent base->clk from moving backward
2020-07-19Merge tag 'sched-urgent-2020-07-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull scheduler fixes from Thomas Gleixner: "A set of scheduler fixes: - Plug a load average accounting race which was introduced with a recent optimization casing load average to show bogus numbers. - Fix the rseq CPU id initialization for new tasks. sched_fork() does not update the rseq CPU id so the id is the stale id of the parent task, which can cause user space data corruption. - Handle a 0 return value of task_h_load() correctly in the load balancer, which does not decrease imbalance and therefore pulls until the maximum number of loops is reached, which might be all tasks just created by a fork bomb" * tag 'sched-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: handle case of task_h_load() returning 0 sched: Fix unreliable rseq cpu_id for new tasks sched: Fix loadavg accounting race
2020-07-19Merge tag 'irq-urgent-2020-07-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull irq fixes from Thomas Gleixner: "Two fixes for the interrupt subsystem: - Make the handling of the firmware node consistent and do not free the node after the domain has been created successfully. The core code stores a pointer to it which can lead to a use after free or double free. This used to "work" because the pointer was not stored when the initial code was written, but at some point later it was required to store it. Of course nobody noticed that the existing users break that way. - Handle affinity setting on inactive interrupts correctly when hierarchical irq domains are enabled. When interrupts are inactive with the modern hierarchical irqdomain design, the interrupt chips are not necessarily in a state where affinity changes can be handled. The legacy irq chip design allowed this because interrupts are immediately fully initialized at allocation time. X86 has a hacky workaround for this, but other implementations do not. This cased malfunction on GIC-V3. Instead of playing whack a mole to find all affected drivers, change the core code to store the requested affinity setting and then establish it when the interrupt is allocated, which makes the X86 hack go away" * tag 'irq-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/affinity: Handle affinity setting on inactive interrupts correctly irqdomain/treewide: Keep firmware node unconditionally allocated
2020-07-19prctl: exe link permission error changed from -EINVAL to -EPERMNicolas Viennot
This brings consistency with the rest of the prctl() syscall where -EPERM is returned when failing a capability check. Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com> Signed-off-by: Adrian Reber <areber@redhat.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Link: https://lore.kernel.org/r/20200719100418.2112740-7-areber@redhat.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19prctl: Allow local CAP_CHECKPOINT_RESTORE to change /proc/self/exeNicolas Viennot
Originally, only a local CAP_SYS_ADMIN could change the exe link, making it difficult for doing checkpoint/restore without CAP_SYS_ADMIN. This commit adds CAP_CHECKPOINT_RESTORE in addition to CAP_SYS_ADMIN for permitting changing the exe link. The following describes the history of the /proc/self/exe permission checks as it may be difficult to understand what decisions lead to this point. * [1] May 2012: This commit introduces the ability of changing /proc/self/exe if the user is CAP_SYS_RESOURCE capable. In the related discussion [2], no clear thread model is presented for what could happen if the /proc/self/exe changes multiple times, or why would the admin be at the mercy of userspace. * [3] Oct 2014: This commit introduces a new API to change /proc/self/exe. The permission no longer checks for CAP_SYS_RESOURCE, but instead checks if the current user is root (uid=0) in its local namespace. In the related discussion [4] it is said that "Controlling exe_fd without privileges may turn out to be dangerous. At least things like tomoyo examine it for making policy decisions (see tomoyo_manager())." * [5] Dec 2016: This commit removes the restriction to change /proc/self/exe at most once. The related discussion [6] informs that the audit subsystem relies on the exe symlink, presumably audit_log_d_path_exe() in kernel/audit.c. * [7] May 2017: This commit changed the check from uid==0 to local CAP_SYS_ADMIN. No discussion. * [8] July 2020: A PoC to spoof any program's /proc/self/exe via ptrace is demonstrated Overall, the concrete points that were made to retain capability checks around changing the exe symlink is that tomoyo_manager() and audit_log_d_path_exe() uses the exe_file path. Christian Brauner said that relying on /proc/<pid>/exe being immutable (or guarded by caps) in a sake of security is a bit misleading. It can only be used as a hint without any guarantees of what code is being executed once execve() returns to userspace. Christian suggested that in the future, we could call audit_log() or similar to inform the admin of all exe link changes, instead of attempting to provide security guarantees via permission checks. However, this proposed change requires the understanding of the security implications in the tomoyo/audit subsystems. [1] b32dfe377102 ("c/r: prctl: add ability to set new mm_struct::exe_file") [2] https://lore.kernel.org/patchwork/patch/292515/ [3] f606b77f1a9e ("prctl: PR_SET_MM -- introduce PR_SET_MM_MAP operation") [4] https://lore.kernel.org/patchwork/patch/479359/ [5] 3fb4afd9a504 ("prctl: remove one-shot limitation for changing exe link") [6] https://lore.kernel.org/patchwork/patch/697304/ [7] 4d28df6152aa ("prctl: Allow local CAP_SYS_ADMIN changing exe_file") [8] https://github.com/nviennot/run_as_exe Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com> Signed-off-by: Adrian Reber <areber@redhat.com> Link: https://lore.kernel.org/r/20200719100418.2112740-6-areber@redhat.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19pid_namespace: use checkpoint_restore_ns_capable() for ns_last_pidAdrian Reber
Use the newly introduced capability CAP_CHECKPOINT_RESTORE to allow writing to ns_last_pid. Signed-off-by: Adrian Reber <areber@redhat.com> Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20200719100418.2112740-4-areber@redhat.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19pid: use checkpoint_restore_ns_capable() for set_tidAdrian Reber
Use the newly introduced capability CAP_CHECKPOINT_RESTORE to allow using clone3() with set_tid set. Signed-off-by: Adrian Reber <areber@redhat.com> Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20200719100418.2112740-3-areber@redhat.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19dma-debug: use named initializers for dir2nameChristoph Hellwig
Make dir2name a little more readable and maintainable by using named initializers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-07-19dma-mapping: add a dma_ops_bypass flag to struct deviceChristoph Hellwig
Several IOMMU drivers have a bypass mode where they can use a direct mapping if the devices DMA mask is large enough. Add generic support to the core dma-mapping code to do that to switch those drivers to a common solution. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-19dma-mapping: make support for dma ops optionalChristoph Hellwig
Avoid the overhead of the dma ops support for tiny builds that only use the direct mapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-17inet: Run SK_LOOKUP BPF program on socket lookupJakub Sitnicki
Run a BPF program before looking up a listening socket on the receive path. Program selects a listening socket to yield as result of socket lookup by calling bpf_sk_assign() helper and returning SK_PASS code. Program can revert its decision by assigning a NULL socket with bpf_sk_assign(). Alternatively, BPF program can also fail the lookup by returning with SK_DROP, or let the lookup continue as usual with SK_PASS on return, when no socket has been selected with bpf_sk_assign(). This lets the user match packets with listening sockets freely at the last possible point on the receive path, where we know that packets are destined for local delivery after undergoing policing, filtering, and routing. With BPF code selecting the socket, directing packets destined to an IP range or to a port range to a single socket becomes possible. In case multiple programs are attached, they are run in series in the order in which they were attached. The end result is determined from return codes of all the programs according to following rules: 1. If any program returned SK_PASS and selected a valid socket, the socket is used as result of socket lookup. 2. If more than one program returned SK_PASS and selected a socket, last selection takes effect. 3. If any program returned SK_DROP, and no program returned SK_PASS and selected a socket, socket lookup fails with -ECONNREFUSED. 4. If all programs returned SK_PASS and none of them selected a socket, socket lookup continues to htable-based lookup. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717103536.397595-5-jakub@cloudflare.com
2020-07-17bpf: Introduce SK_LOOKUP program type with a dedicated attach pointJakub Sitnicki
Add a new program type BPF_PROG_TYPE_SK_LOOKUP with a dedicated attach type BPF_SK_LOOKUP. The new program kind is to be invoked by the transport layer when looking up a listening socket for a new connection request for connection oriented protocols, or when looking up an unconnected socket for a packet for connection-less protocols. When called, SK_LOOKUP BPF program can select a socket that will receive the packet. This serves as a mechanism to overcome the limits of what bind() API allows to express. Two use-cases driving this work are: (1) steer packets destined to an IP range, on fixed port to a socket 192.0.2.0/24, port 80 -> NGINX socket (2) steer packets destined to an IP address, on any port to a socket 198.51.100.1, any port -> L7 proxy socket In its run-time context program receives information about the packet that triggered the socket lookup. Namely IP version, L4 protocol identifier, and address 4-tuple. Context can be further extended to include ingress interface identifier. To select a socket BPF program fetches it from a map holding socket references, like SOCKMAP or SOCKHASH, and calls bpf_sk_assign(ctx, sk, ...) helper to record the selection. Transport layer then uses the selected socket as a result of socket lookup. In its basic form, SK_LOOKUP acts as a filter and hence must return either SK_PASS or SK_DROP. If the program returns with SK_PASS, transport should look for a socket to receive the packet, or use the one selected by the program if available, while SK_DROP informs the transport layer that the lookup should fail. This patch only enables the user to attach an SK_LOOKUP program to a network namespace. Subsequent patches hook it up to run on local delivery path in ipv4 and ipv6 stacks. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717103536.397595-3-jakub@cloudflare.com
2020-07-17bpf, netns: Handle multiple link attachmentsJakub Sitnicki
Extend the BPF netns link callbacks to rebuild (grow/shrink) or update the prog_array at given position when link gets attached/updated/released. This let's us lift the limit of having just one link attached for the new attach type introduced by subsequent patch. No functional changes intended. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200717103536.397595-2-jakub@cloudflare.com
2020-07-18futex: Remove unused or redundant includesAndré Almeida
Since 82af7aca ("Removal of FUTEX_FD"), some includes related to file operations aren't needed anymore. More investigation around the includes showed that a lot of includes aren't required for compilation, possible due to redundant includes. Simplify the code by removing unused includes. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200702202843.520764-4-andrealmeid@collabora.com
2020-07-18futex: Consistently use fshared as booleanAndré Almeida
Since fshared is only conveying true/false values, declare it as bool. In get_futex_key() the usage of fshared can be restricted to the first part of the function. If fshared is false the function is terminated early and the subsequent code can use a constant 'true' instead of the variable. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200702202843.520764-5-andrealmeid@collabora.com
2020-07-17futex: Remove needless goto'sAndré Almeida
As stated in the coding style documentation, "if there is no cleanup needed then just return directly", instead of jumping to a label and then returning. Remove such goto's and replace with a return statement. When there's a ternary operator on the return value, replace it with the result of the operation when it is logically possible to determine it by the control flow. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200702202843.520764-3-andrealmeid@collabora.com
2020-07-17futex: Remove put_futex_key()André Almeida
Since 4b39f99c ("futex: Remove {get,drop}_futex_key_refs()"), put_futex_key() is empty. Remove all references for this function and the then redundant labels. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200702202843.520764-2-andrealmeid@collabora.com
2020-07-17genirq/affinity: Handle affinity setting on inactive interrupts correctlyThomas Gleixner
Setting interrupt affinity on inactive interrupts is inconsistent when hierarchical irq domains are enabled. The core code should just store the affinity and not call into the irq chip driver for inactive interrupts because the chip drivers may not be in a state to handle such requests. X86 has a hacky workaround for that but all other irq chips have not which causes problems e.g. on GIC V3 ITS. Instead of adding more ugly hacks all over the place, solve the problem in the core code. If the affinity is set on an inactive interrupt then: - Store it in the irq descriptors affinity mask - Update the effective affinity to reflect that so user space has a consistent view - Don't call into the irq chip driver This is the core equivalent of the X86 workaround and works correctly because the affinity setting is established in the irq chip when the interrupt is activated later on. Note, that this is only effective when hierarchical irq domains are enabled by the architecture. Doing it unconditionally would break legacy irq chip implementations. For hierarchial irq domains this works correctly as none of the drivers can have a dependency on affinity setting in inactive state by design. Remove the X86 workaround as it is not longer required. Fixes: 02edee152d6e ("x86/apic/vector: Ignore set_affinity call for inactive interrupts") Reported-by: Ali Saidi <alisaidi@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ali Saidi <alisaidi@amazon.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de
2020-07-17timers: Lower base clock forwarding thresholdFrederic Weisbecker
There is nothing that prevents from forwarding the base clock if it's one jiffy off. The reason for this arbitrary limit of two jiffies is historical and does not longer exist. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-13-frederic@kernel.org
2020-07-17timers: Remove must_forward_clkFrederic Weisbecker
There is no reason to keep this guard around. The code makes sure that base->clk remains sane and won't be forwarded beyond jiffies nor set backward. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-12-frederic@kernel.org
2020-07-17timers: Spare timer softirq until next expiryFrederic Weisbecker
Now that the core timer infrastructure doesn't depend anymore on periodic base->clk increments, even when the CPU is not in NO_HZ mode, timer softirqs can be skipped until there are timers to expire. Some spurious softirqs can still remain since base->next_expiry doesn't keep track of canceled timers but this still reduces the number of softirqs significantly: ~15 times less for HZ=1000 and ~5 times less for HZ=100. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-11-frederic@kernel.org
2020-07-17timers: Expand clk forward logic beyond nohzFrederic Weisbecker
As for next_expiry, the base->clk catch up logic will be expanded beyond NOHZ in order to avoid triggering useless softirqs. If softirqs should only fire to expire pending timers, periodic base->clk increments must be skippable for random amounts of time. Therefore prepare to catch-up with missing updates whenever an up-to-date base clock is needed. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-10-frederic@kernel.org
2020-07-17timers: Reuse next expiry cache after nohz exitFrederic Weisbecker
Now that the next expiry it tracked unconditionally when a timer is added, this information can be reused on a tick firing after exiting nohz. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-9-frederic@kernel.org
2020-07-17timers: Always keep track of next expiryFrederic Weisbecker
So far next expiry was only tracked while the CPU was in nohz_idle mode in order to cope with missing ticks that can't increment the base->clk periodically anymore. This logic is going to be expanded beyond nohz in order to spare timer softirqs so do it unconditionally. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-8-frederic@kernel.org
2020-07-17timers: Optimize _next_timer_interrupt() level iterationFrederic Weisbecker
If a level has a timer that expires before reaching the next level, there is no need to iterate further. The next level is reached when the 3 lower bits of the current level are cleared. If the next event happens before/during that, the next levels won't provide an earlier expiration. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-7-frederic@kernel.org
2020-07-17timers: Add comments about calc_index() ceiling workFrederic Weisbecker
calc_index() adds 1 unit of the level granularity to the expiry passed in parameter to ensure that the timer doesn't expire too early. Add a comment to explain that and the resulting layout in the wheel. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-6-frederic@kernel.org
2020-07-17timers: Move trigger_dyntick_cpu() to enqueue_timer()Frederic Weisbecker
Consolidate the code by calling trigger_dyntick_cpu() from enqueue_timer() instead of calling it from all its callers. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-5-frederic@kernel.org
2020-07-17timers: Use only bucket expiry for base->next_expiry valueAnna-Maria Behnsen
The bucket expiry time is the effective expriy time of timers and is greater than or equal to the requested timer expiry time. This is due to the guarantee that timers never expire early and the reduced expiry granularity in the secondary wheel levels. When a timer is enqueued, trigger_dyntick_cpu() checks whether the timer is the new first timer. This check compares next_expiry with the requested timer expiry value and not with the effective expiry value of the bucket into which the timer was queued. Storing the requested timer expiry value in base->next_expiry can lead to base->clk going backwards if the requested timer expiry value is smaller than base->clk. Commit 30c66fc30ee7 ("timer: Prevent base->clk from moving backward") worked around this by preventing the store when timer->expiry is before base->clk, but did not fix the underlying problem. Use the expiry value of the bucket into which the timer is queued to do the new first timer check. This fixes the base->clk going backward problem. The workaround of commit 30c66fc30ee7 ("timer: Prevent base->clk from moving backward") in trigger_dyntick_cpu() is not longer necessary as the timers bucket expiry is guaranteed to be greater than or equal base->clk. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200717140551.29076-4-frederic@kernel.org
2020-07-17timers: Preserve higher bits of expiration on index calculationFrederic Weisbecker
The higher bits of the timer expiration are cropped while calling calc_index() due to the implicit cast from unsigned long to unsigned int. This loss shouldn't have consequences on the current code since all the computation to calculate the index is done on the lower 32 bits. However to prepare for returning the actual bucket expiration from calc_index() in order to properly fix base->next_expiry updates, the higher bits need to be preserved. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200717140551.29076-3-frederic@kernel.org
2020-07-17timer: Fix wheel index calculation on last levelFrederic Weisbecker
When an expiration delta falls into the last level of the wheel, that delta has be compared against the maximum possible delay and reduced to fit in if necessary. However instead of comparing the delta against the maximum, the code compares the actual expiry against the maximum. Then instead of fixing the delta to fit in, it sets the maximum delta as the expiry value. This can result in various undesired outcomes, the worst possible one being a timer expiring 15 days ahead to fire immediately. Fixes: 500462a9de65 ("timers: Switch to a non-cascading wheel") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200717140551.29076-2-frederic@kernel.org
2020-07-16sched/fair: handle case of task_h_load() returning 0Vincent Guittot
task_h_load() can return 0 in some situations like running stress-ng mmapfork, which forks thousands of threads, in a sched group on a 224 cores system. The load balance doesn't handle this correctly because env->imbalance never decreases and it will stop pulling tasks only after reaching loop_max, which can be equal to the number of running tasks of the cfs. Make sure that imbalance will be decreased by at least 1. misfit task is the other feature that doesn't handle correctly such situation although it's probably more difficult to face the problem because of the smaller number of CPUs and running tasks on heterogenous system. We can't simply ensure that task_h_load() returns at least one because it would imply to handle underflow in other places. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: <stable@vger.kernel.org> # v4.4+ Link: https://lkml.kernel.org/r/20200710152426.16981-1-vincent.guittot@linaro.org
2020-07-16treewide: Remove uninitialized_var() usageKees Cook
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16bpf: cpumap: Implement XDP_REDIRECT for eBPF programs attached to map entriesLorenzo Bianconi
Introduce XDP_REDIRECT support for eBPF programs attached to cpumap entries. This patch has been tested on Marvell ESPRESSObin using a modified version of xdp_redirect_cpu sample in order to attach a XDP program to CPUMAP entries to perform a redirect on the mvneta interface. In particular the following scenario has been tested: rq (cpu0) --> mvneta - XDP_REDIRECT (cpu0) --> CPUMAP - XDP_REDIRECT (cpu1) --> mvneta $./xdp_redirect_cpu -p xdp_cpu_map0 -d eth0 -c 1 -e xdp_redirect \ -f xdp_redirect_kern.o -m tx_port -r eth0 tx: 285.2 Kpps rx: 285.2 Kpps Attaching a simple XDP program on eth0 to perform XDP_TX gives comparable results: tx: 288.4 Kpps rx: 288.4 Kpps Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/2cf8373a731867af302b00c4ff16c122630c4980.1594734381.git.lorenzo@kernel.org
2020-07-16bpf: cpumap: Add the possibility to attach an eBPF program to cpumapLorenzo Bianconi
Introduce the capability to attach an eBPF program to cpumap entries. The idea behind this feature is to add the possibility to define on which CPU run the eBPF program if the underlying hw does not support RSS. Current supported verdicts are XDP_DROP and XDP_PASS. This patch has been tested on Marvell ESPRESSObin using xdp_redirect_cpu sample available in the kernel tree to identify possible performance regressions. Results show there are no observable differences in packet-per-second: $./xdp_redirect_cpu --progname xdp_cpu_map0 --dev eth0 --cpu 1 rx: 354.8 Kpps rx: 356.0 Kpps rx: 356.8 Kpps rx: 356.3 Kpps rx: 356.6 Kpps rx: 356.6 Kpps rx: 356.7 Kpps rx: 355.8 Kpps rx: 356.8 Kpps rx: 356.8 Kpps Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/5c9febdf903d810b3415732e5cd98491d7d9067a.1594734381.git.lorenzo@kernel.org
2020-07-16cpumap: Formalize map value as a named structLorenzo Bianconi
As it has been already done for devmap, introduce 'struct bpf_cpumap_val' to formalize the expected values that can be passed in for a CPUMAP. Update cpumap code to use the struct. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/754f950674665dae6139c061d28c1d982aaf4170.1594734381.git.lorenzo@kernel.org
2020-07-16cpumap: Use non-locked version __ptr_ring_consume_batchedJesper Dangaard Brouer
Commit 77361825bb01 ("bpf: cpumap use ptr_ring_consume_batched") changed away from using single frame ptr_ring dequeue (__ptr_ring_consume) to consume a batched, but it uses a locked version, which as the comment explain isn't needed. Change to use the non-locked version __ptr_ring_consume_batched. Fixes: 77361825bb01 ("bpf: cpumap use ptr_ring_consume_batched") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/a9c7d06f9a009e282209f0c8c7b2c5d9b9ad60b9.1594734381.git.lorenzo@kernel.org
2020-07-16dma-mapping: inline the fast path dma-direct callsChristoph Hellwig
Inline the single page map/unmap/sync dma-direct calls into the now out of line generic wrappers. This restores the behavior of a single function call that we had before moving the generic calls out of line. Besides the dma-mapping callers there are just a few callers in IOMMU drivers that have a bypass mode, and more of those are going to be switched to the generic bypass soon. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-16dma-mapping: move the remaining DMA API calls out of lineChristoph Hellwig
For a long time the DMA API has been implemented inline in dma-mapping.h, but the function bodies can be quite large. Move them all out of line. This also removes all the dma_direct_* exports as those are just implementation details and should never be used by drivers directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>