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2021-01-22workqueue: Use cpu_possible_mask instead of cpu_active_mask to break affinityLai Jiangshan1-1/+1
The scheduler won't break affinity for us any more, and we should "emulate" the same behavior when the scheduler breaks affinity for us. The behavior is "changing the cpumask to cpu_possible_mask". And there might be some other CPUs online later while the worker is still running with the pending work items. The worker should be allowed to use the later online CPUs as before and process the work items ASAP. If we use cpu_active_mask here, we can't achieve this goal but using cpu_possible_mask can. Fixes: 06249738a41a ("workqueue: Manually break affinity on hotplug") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Acked-by: Tejun Heo <tj@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20210111152638.2417-4-jiangshanlai@gmail.com
2021-01-22sched/core: Print out straggler tasks in sched_cpu_dying()Valentin Schneider1-1/+23
Since commit 1cf12e08bc4d ("sched/hotplug: Consolidate task migration on CPU unplug") tasks are expected to move themselves out of a out-going CPU. For most tasks this will be done automagically via BALANCE_PUSH, but percpu kthreads will have to cooperate and move themselves away one way or another. Currently, some percpu kthreads (workqueues being a notable exemple) do not cooperate nicely and can end up on an out-going CPU at the time sched_cpu_dying() is invoked. Print the dying rq's tasks to shed some light on the stragglers. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20210113183141.11974-1-valentin.schneider@arm.com
2021-01-22lockdep: report broken irq restorationMark Rutland2-0/+12
We generally expect local_irq_save() and local_irq_restore() to be paired and sanely nested, and so local_irq_restore() expects to be called with irqs disabled. Thus, within local_irq_restore() we only trace irq flag changes when unmasking irqs. This means that a sequence such as: | local_irq_disable(); | local_irq_save(flags); | local_irq_enable(); | local_irq_restore(flags); ... is liable to break things, as the local_irq_restore() would mask irqs without tracing this change. Similar problems may exist for architectures whose arch_irq_restore() function depends on being called with irqs disabled. We don't consider such sequences to be a good idea, so let's define those as forbidden, and add tooling to detect such broken cases. This patch adds debug code to WARN() when raw_local_irq_restore() is called with irqs enabled. As raw_local_irq_restore() is expected to pair with raw_local_irq_save(), it should never be called with irqs enabled. To avoid the possibility of circular header dependencies between irqflags.h and bug.h, the warning is handled in a separate C file. The new code is all conditional on a new CONFIG_DEBUG_IRQFLAGS symbol which is independent of CONFIG_TRACE_IRQFLAGS. As noted above such cases will confuse lockdep, so CONFIG_DEBUG_LOCKDEP now selects CONFIG_DEBUG_IRQFLAGS. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210111153707.10071-1-mark.rutland@arm.com
2021-01-21Merge tag 'printk-for-5.11-printk-rework-fixup' of ↵Linus Torvalds2-12/+30
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk fixes from Petr Mladek: - Fix line counting and buffer size calculation. Both regressions caused that a reader buffer might not get filled as much as possible. - Restore non-documented behavior of printk() reader API and make it official. It did not fill the last byte of the provided buffer before 5.10. Two architectures, powerpc and um, used it to add the trailing '\0'. There might theoretically be more callers depending on this behavior in userspace. * tag 'printk-for-5.11-printk-rework-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: fix buffer overflow potential for print_text() printk: fix kmsg_dump_get_buffer length calulations printk: ringbuffer: fix line counting
2021-01-21Merge branch 'printk-rework' into for-linusPetr Mladek2-12/+30
2021-01-21bpf: Split cgroup_bpf_enabled per attach typeStanislav Fomichev1-8/+6
When we attach any cgroup hook, the rest (even if unused/unattached) start to contribute small overhead. In particular, the one we want to avoid is __cgroup_bpf_run_filter_skb which does two redirections to get to the cgroup and pushes/pulls skb. Let's split cgroup_bpf_enabled to be per-attach to make sure only used attach types trigger. I've dropped some existing high-level cgroup_bpf_enabled in some places because BPF_PROG_CGROUP_XXX_RUN macros usually have another cgroup_bpf_enabled check. I also had to copy-paste BPF_CGROUP_RUN_SA_PROG_LOCK for GETPEERNAME/GETSOCKNAME because type for cgroup_bpf_enabled[type] has to be constant and known at compile time. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210115163501.805133-4-sdf@google.com
2021-01-21bpf: Try to avoid kzalloc in cgroup/{s,g}etsockoptStanislav Fomichev1-7/+45
When we attach a bpf program to cgroup/getsockopt any other getsockopt() syscall starts incurring kzalloc/kfree cost. Let add a small buffer on the stack and use it for small (majority) {s,g}etsockopt values. The buffer is small enough to fit into the cache line and cover the majority of simple options (most of them are 4 byte ints). It seems natural to do the same for setsockopt, but it's a bit more involved when the BPF program modifies the data (where we have to kmalloc). The assumption is that for the majority of setsockopt calls (which are doing pure BPF options or apply policy) this will bring some benefit as well. Without this patch (we remove about 1% __kmalloc): 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt | --3.30%--__cgroup_bpf_run_filter_getsockopt | --0.81%--__kmalloc Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210115163501.805133-3-sdf@google.com
2021-01-21bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVEStanislav Fomichev1-0/+46
Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE. We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom call in do_tcp_getsockopt using the on-stack data. This removes 3% overhead for locking/unlocking the socket. Without this patch: 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt | --3.30%--__cgroup_bpf_run_filter_getsockopt | --0.81%--__kmalloc With the patch applied: 0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern Note, exporting uapi/tcp.h requires removing netinet/tcp.h from test_progs.h because those headers have confliciting definitions. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com
2021-01-21bpf: Permit size-0 datasecYonghong Song1-5/+0
llvm patch https://reviews.llvm.org/D84002 permitted to emit empty rodata datasec if the elf .rodata section contains read-only data from local variables. These local variables will be not emitted as BTF_KIND_VARs since llvm converted these local variables as static variables with private linkage without debuginfo types. Such an empty rodata datasec will make skeleton code generation easy since for skeleton a rodata struct will be generated if there is a .rodata elf section. The existence of a rodata btf datasec is also consistent with the existence of a rodata map created by libbpf. The btf with such an empty rodata datasec will fail in the kernel though as kernel will reject a datasec with zero vlen and zero size. For example, for the below code, int sys_enter(void *ctx) { int fmt[6] = {1, 2, 3, 4, 5, 6}; int dst[6]; bpf_probe_read(dst, sizeof(dst), fmt); return 0; } We got the below btf (bpftool btf dump ./test.o): [1] PTR '(anon)' type_id=0 [2] FUNC_PROTO '(anon)' ret_type_id=3 vlen=1 'ctx' type_id=1 [3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED [4] FUNC 'sys_enter' type_id=2 linkage=global [5] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=SIGNED [6] ARRAY '(anon)' type_id=5 index_type_id=7 nr_elems=4 [7] INT '__ARRAY_SIZE_TYPE__' size=4 bits_offset=0 nr_bits=32 encoding=(none) [8] VAR '_license' type_id=6, linkage=global-alloc [9] DATASEC '.rodata' size=0 vlen=0 [10] DATASEC 'license' size=0 vlen=1 type_id=8 offset=0 size=4 When loading the ./test.o to the kernel with bpftool, we see the following error: libbpf: Error loading BTF: Invalid argument(22) libbpf: magic: 0xeb9f ... [6] ARRAY (anon) type_id=5 index_type_id=7 nr_elems=4 [7] INT __ARRAY_SIZE_TYPE__ size=4 bits_offset=0 nr_bits=32 encoding=(none) [8] VAR _license type_id=6 linkage=1 [9] DATASEC .rodata size=24 vlen=0 vlen == 0 libbpf: Error loading .BTF into kernel: -22. BTF is optional, ignoring. Basically, libbpf changed .rodata datasec size to 24 since elf .rodata section size is 24. The kernel then rejected the BTF since vlen = 0. Note that the above kernel verifier failure can be worked around with changing local variable "fmt" to a static or global, optionally const, variable. This patch permits a datasec with vlen = 0 in kernel. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210119153519.3901963-1-yhs@fb.com
2021-01-21net, xdp: Introduce __xdp_build_skb_from_frame utility routineLorenzo Bianconi1-44/+2
Introduce __xdp_build_skb_from_frame utility routine to build the skb from xdp_frame. Rely on __xdp_build_skb_from_frame in cpumap code. 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/4f9f4c6b3dd3933770c617eb6689dbc0c6e25863.1610475660.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-01-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski8-13/+27
Conflicts: drivers/net/can/dev.c commit 03f16c5075b2 ("can: dev: can_restart: fix use after free bug") commit 3e77f70e7345 ("can: dev: move driver related infrastructure into separate subdir") Code move. drivers/net/dsa/b53/b53_common.c commit 8e4052c32d6b ("net: dsa: b53: fix an off by one in checking "vlan->vid"") commit b7a9e0da2d1c ("net: switchdev: remove vid_begin -> vid_end range from VLAN objects") Field rename. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-20Merge tag 'net-5.11-rc5' of ↵Linus Torvalds7-13/+24
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Networking fixes for 5.11-rc5, including fixes from bpf, wireless, and can trees. Current release - regressions: - nfc: nci: fix the wrong NCI_CORE_INIT parameters Current release - new code bugs: - bpf: allow empty module BTFs Previous releases - regressions: - bpf: fix signed_{sub,add32}_overflows type handling - tcp: do not mess with cloned skbs in tcp_add_backlog() - bpf: prevent double bpf_prog_put call from bpf_tracing_prog_attach - bpf: don't leak memory in bpf getsockopt when optlen == 0 - tcp: fix potential use-after-free due to double kfree() - mac80211: fix encryption issues with WEP - devlink: use right genl user_ptr when handling port param get/set - ipv6: set multicast flag on the multicast route - tcp: fix TCP_USER_TIMEOUT with zero window Previous releases - always broken: - bpf: local storage helpers should check nullness of owner ptr passed - mac80211: fix incorrect strlen of .write in debugfs - cls_flower: call nla_ok() before nla_next() - skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too" * tag 'net-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (52 commits) net: systemport: free dev before on error path net: usb: cdc_ncm: don't spew notifications net: mscc: ocelot: Fix multicast to the CPU port tcp: Fix potential use-after-free due to double kfree() bpf: Fix signed_{sub,add32}_overflows type handling can: peak_usb: fix use after free bugs can: vxcan: vxcan_xmit: fix use after free bug can: dev: can_restart: fix use after free bug tcp: fix TCP socket rehash stats mis-accounting net: dsa: b53: fix an off by one in checking "vlan->vid" tcp: do not mess with cloned skbs in tcp_add_backlog() selftests: net: fib_tests: remove duplicate log test net: nfc: nci: fix the wrong NCI_CORE_INIT parameters sh_eth: Fix power down vs. is_opened flag ordering net: Disable NETIF_F_HW_TLS_RX when RXCSUM is disabled netfilter: rpfilter: mask ecn bits before fib lookup udp: mask TOS bits in udp_v4_early_demux() xsk: Clear pool even for inactive queues bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback sh_eth: Make PHY access aware of Runtime PM to fix reboot crash ...
2021-01-20bpf: Fix signed_{sub,add32}_overflows type handlingDaniel Borkmann1-3/+3
Fix incorrect signed_{sub,add32}_overflows() input types (and a related buggy comment). It looks like this might have slipped in via copy/paste issue, also given prior to 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") the signature of signed_sub_overflows() had s64 a and s64 b as its input args whereas now they are truncated to s32. Thus restore proper types. Also, the case of signed_add32_overflows() is not consistent to signed_sub32_overflows(). Both have s32 as inputs, therefore align the former. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: De4dCr0w <sa516203@mail.ustc.edu.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-01-20Merge tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+3
Pull task_work fix from Jens Axboe: "The TIF_NOTIFY_SIGNAL change inadvertently removed the unconditional task_work run we had in get_signal(). This caused a regression for some setups, since we're relying on eg ____fput() being run to close and release, for example, a pipe and wake the other end. For 5.11, I prefer the simple solution of just reinstating the unconditional run, even if it conceptually doesn't make much sense - if you need that kind of guarantee, you should be using TWA_SIGNAL instead of TWA_NOTIFY. But it's the trivial fix for 5.11, and would ensure that other potential gotchas/assumptions for task_work don't regress for 5.11. We're looking into further simplifying the task_work notifications for 5.12 which would resolve that too" * tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block: task_work: unconditionally run task_work from get_signal()
2021-01-20bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callbackMircea Cirjaliu1-1/+1
I assume this was obtained by copy/paste. Point it to bpf_map_peek_elem() instead of bpf_map_pop_elem(). In practice it may have been less likely hit when under JIT given shielded via 84430d4232c3 ("bpf, verifier: avoid retpoline for map push/pop/peek operation"). Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Signed-off-by: Mircea Cirjaliu <mcirjaliu@bitdefender.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Mauricio Vasquez <mauriciovasquezbernal@gmail.com> Link: https://lore.kernel.org/bpf/AM7PR02MB6082663DFDCCE8DA7A6DD6B1BBA30@AM7PR02MB6082.eurprd02.prod.outlook.com
2021-01-19cgroup: fix psi monitor for root cgroupOdin Ugedal1-1/+3
Fix NULL pointer dereference when adding new psi monitor to the root cgroup. PSI files for root cgroup was introduced in df5ba5be742 by using system wide psi struct when reading, but file write/monitor was not properly fixed. Since the PSI config for the root cgroup isn't initialized, the current implementation tries to lock a NULL ptr, resulting in a crash. Can be triggered by running this as root: $ tee /sys/fs/cgroup/cpu.pressure <<< "some 10000 1000000" Signed-off-by: Odin Ugedal <odin@uged.al> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Dan Schatzberg <dschatzberg@fb.com> Fixes: df5ba5be7425 ("kernel/sched/psi.c: expose pressure metrics on root cgroup") Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: stable@vger.kernel.org # 5.2+ Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-19printk: fix buffer overflow potential for print_text()John Ogness1-9/+27
Before the commit 896fbe20b4e2333fb55 ("printk: use the lockless ringbuffer"), msg_print_text() would only write up to size-1 bytes into the provided buffer. Some callers expect this behavior and append a terminator to returned string. In particular: arch/powerpc/xmon/xmon.c:dump_log_buf() arch/um/kernel/kmsg_dump.c:kmsg_dumper_stdout() msg_print_text() has been replaced by record_print_text(), which currently fills the full size of the buffer. This causes a buffer overflow for the above callers. Change record_print_text() so that it will only use size-1 bytes for text data. Also, for paranoia sakes, add a terminator after the text data. And finally, document this behavior so that it is clear that only size-1 bytes are used and a terminator is added. Fixes: 896fbe20b4e2333fb55 ("printk: use the lockless ringbuffer") Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210114170412.4819-1-john.ogness@linutronix.de
2021-01-19module: harden ELF info handlingFrank van der Linden3-21/+126
5fdc7db644 ("module: setup load info before module_sig_check()") moved the ELF setup, so that it was done before the signature check. This made the module name available to signature error messages. However, the checks for ELF correctness in setup_load_info are not sufficient to prevent bad memory references due to corrupted offset fields, indices, etc. So, there's a regression in behavior here: a corrupt and unsigned (or badly signed) module, which might previously have been rejected immediately, can now cause an oops/crash. Harden ELF handling for module loading by doing the following: - Move the signature check back up so that it comes before ELF initialization. It's best to do the signature check to see if we can trust the module, before using the ELF structures inside it. This also makes checks against info->len more accurate again, as this field will be reduced by the length of the signature in mod_check_sig(). The module name is now once again not available for error messages during the signature check, but that seems like a fair tradeoff. - Check if sections have offset / size fields that at least don't exceed the length of the module. - Check if sections have section name offsets that don't fall outside the section name table. - Add a few other sanity checks against invalid section indices, etc. This is not an exhaustive consistency check, but the idea is to at least get through the signature and blacklist checks without crashing because of corrupted ELF info, and to error out gracefully for most issues that would have caused problems later on. Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-01-18module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbolsFangrui Song1-2/+19
clang-12 -fno-pic (since https://github.com/llvm/llvm-project/commit/a084c0388e2a59b9556f2de0083333232da3f1d6) can emit `call __stack_chk_fail@PLT` instead of `call __stack_chk_fail` on x86. The two forms should have identical behaviors on x86-64 but the former causes GNU as<2.37 to produce an unreferenced undefined symbol _GLOBAL_OFFSET_TABLE_. (On x86-32, there is an R_386_PC32 vs R_386_PLT32 difference but the linker behavior is identical as far as Linux kernel is concerned.) Simply ignore _GLOBAL_OFFSET_TABLE_ for now, like what scripts/mod/modpost.c:ignore_undef_symbol does. This also fixes the problem for gcc/clang -fpie and -fpic, which may emit `call foo@PLT` for external function calls on x86. Note: ld -z defs and dynamic loaders do not error for unreferenced undefined symbols so the module loader is reading too much. If we ever need to ignore more symbols, the code should be refactored to ignore unreferenced symbols. Cc: <stable@vger.kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1250 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27178 Reported-by: Marco Elver <elver@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Marco Elver <elver@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-01-16Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski7-206/+366
Daniel Borkmann says: ==================== pull-request: bpf-next 2021-01-16 1) Extend atomic operations to the BPF instruction set along with x86-64 JIT support, that is, atomic{,64}_{xchg,cmpxchg,fetch_{add,and,or,xor}}, from Brendan Jackman. 2) Add support for using kernel module global variables (__ksym externs in BPF programs) retrieved via module's BTF, from Andrii Nakryiko. 3) Generalize BPF stackmap's buildid retrieval and add support to have buildid stored in mmap2 event for perf, from Jiri Olsa. 4) Various fixes for cross-building BPF sefltests out-of-tree which then will unblock wider automated testing on ARM hardware, from Jean-Philippe Brucker. 5) Allow to retrieve SOL_SOCKET opts from sock_addr progs, from Daniel Borkmann. 6) Clean up driver's XDP buffer init and split into two helpers to init per- descriptor and non-changing fields during processing, from Lorenzo Bianconi. 7) Minor misc improvements to libbpf & bpftool, from Ian Rogers. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (41 commits) perf: Add build id data in mmap2 event bpf: Add size arg to build_id_parse function bpf: Move stack_map_get_build_id into lib bpf: Document new atomic instructions bpf: Add tests for new BPF atomic operations bpf: Add bitwise atomic instructions bpf: Pull out a macro for interpreting atomic ALU operations bpf: Add instructions for atomic_[cmp]xchg bpf: Add BPF_FETCH field / create atomic_fetch_add instruction bpf: Move BPF_STX reserved field check into BPF_STX verifier code bpf: Rename BPF_XADD and prepare to encode other atomics in .imm bpf: x86: Factor out a lookup table for some ALU opcodes bpf: x86: Factor out emission of REX byte bpf: x86: Factor out emission of ModR/M for *(reg + off) tools/bpftool: Add -Wall when building BPF programs bpf, libbpf: Avoid unused function warning on bpf_tail_call_static selftests/bpf: Install btf_dump test cases selftests/bpf: Fix installation of urandom_read selftests/bpf: Move generated test files to $(TEST_GEN_FILES) selftests/bpf: Fix out-of-tree build ... ==================== Link: https://lore.kernel.org/r/20210116012922.17823-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-16Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski6-9/+20
Daniel Borkmann says: ==================== pull-request: bpf 2021-01-16 1) Fix a double bpf_prog_put() for BPF_PROG_{TYPE_EXT,TYPE_TRACING} types in link creation's error path causing a refcount underflow, from Jiri Olsa. 2) Fix BTF validation errors for the case where kernel modules don't declare any new types and end up with an empty BTF, from Andrii Nakryiko. 3) Fix BPF local storage helpers to first check their {task,inode} owners for being NULL before access, from KP Singh. 4) Fix a memory leak in BPF setsockopt handling for the case where optlen is zero and thus temporary optval buffer should be freed, from Stanislav Fomichev. 5) Fix a syzbot memory allocation splat in BPF_PROG_TEST_RUN infra for raw_tracepoint caused by too big ctx_size_in, from Song Liu. 6) Fix LLVM code generation issues with verifier where PTR_TO_MEM{,_OR_NULL} registers were spilled to stack but not recognized, from Gilad Reti. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: MAINTAINERS: Update my email address selftests/bpf: Add verifier test for PTR_TO_MEM spill bpf: Support PTR_TO_MEM{,_OR_NULL} register spilling bpf: Reject too big ctx_size_in for raw_tp test run libbpf: Allow loading empty BTFs bpf: Allow empty module BTFs bpf: Don't leak memory in bpf getsockopt when optlen == 0 bpf: Update local storage test to check handling of null ptrs bpf: Fix typo in bpf_inode_storage.c bpf: Local storage helpers should check nullness of owner ptr passed bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach ==================== Link: https://lore.kernel.org/r/20210116002025.15706-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15cpuset: fix typos in commentsAubrey Li1-3/+3
Change hierachy to hierarchy and congifured to configured, no functionality changed. Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-15cgroup: cgroup.{procs,threads} factor out common partsMichal Koutný1-41/+14
The functions cgroup_threads_write and cgroup_procs_write are almost identical. In order to reduce duplication, factor out the common code in similar fashion we already do for other threadgroup/task functions. No functional changes are intended. Suggested-by: Hao Lee <haolee.swjtu@gmail.com> Signed-off-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-15cgroup-v1: add disabled controller check in cgroup1_parse_param()Chen Zhou1-0/+3
When mounting a cgroup hierarchy with disabled controller in cgroup v1, all available controllers will be attached. For example, boot with cgroup_no_v1=cpu or cgroup_disable=cpu, and then mount with "mount -t cgroup -ocpu cpu /sys/fs/cgroup/cpu", then all enabled controllers will be attached except cpu. Fix this by adding disabled controller check in cgroup1_parse_param(). If the specified controller is disabled, just return error with information "Disabled controller xx" rather than attaching all the other enabled controllers. Fixes: f5dfb5315d34 ("cgroup: take options parsing into ->parse_monolithic()") Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Reviewed-by: Zefan Li <lizefan.x@bytedance.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-15audit: Remove leftover reference to the audit_taskletDavidlohr Bueso1-1/+1
This was replaced with a kauditd_wait kthread long ago, back in: b7d1125817c (AUDIT: Send netlink messages from a separate kernel thread) Update the stale comment. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-15printk: fix kmsg_dump_get_buffer length calulationsJohn Ogness1-2/+2
kmsg_dump_get_buffer() uses @syslog to determine if the syslog prefix should be written to the buffer. However, when calculating the maximum number of records that can fit into the buffer, it always counts the bytes from the syslog prefix. Use @syslog when calculating the maximum number of records that can fit into the buffer. Fixes: e2ae715d66bf ("kmsg - kmsg_dump() use iterator to receive log buffer content") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210113164413.1599-1-john.ogness@linutronix.de
2021-01-15printk: ringbuffer: fix line countingJohn Ogness1-1/+1
Counting text lines in a record simply involves counting the number of newline characters (+1). However, it is searching the full data block for newline characters, even though the text data can be (and often is) a subset of that area. Since the extra area in the data block was never initialized, the result is that extra newlines may be seen and counted. Restrict newline searching to the text data length. Fixes: b6cf8b3f3312 ("printk: add lockless ringbuffer") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210113144234.6545-1-john.ogness@linutronix.de
2021-01-15perf: Add build id data in mmap2 eventJiri Olsa1-4/+28
Adding support to carry build id data in mmap2 event. The build id data replaces maj/min/ino/ino_generation fields, which are also used to identify map's binary, so it's ok to replace them with build id data: union { struct { u32 maj; u32 min; u64 ino; u64 ino_generation; }; struct { u8 build_id_size; u8 __reserved_1; u16 __reserved_2; u8 build_id[20]; }; }; Replaced maj/min/ino/ino_generation fields give us size of 24 bytes. We use 20 bytes for build id data, 1 byte for size and rest is unused. There's new misc bit for mmap2 to signal there's build id data in it: #define PERF_RECORD_MISC_MMAP_BUILD_ID (1 << 14) Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/bpf/20210114134044.1418404-4-jolsa@kernel.org
2021-01-15bpf: Add size arg to build_id_parse functionJiri Olsa1-1/+1
It's possible to have other build id types (other than default SHA1). Currently there's also ld support for MD5 build id. Adding size argument to build_id_parse function, that returns (if defined) size of the parsed build id, so we can recognize the build id type. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210114134044.1418404-3-jolsa@kernel.org
2021-01-15bpf: Move stack_map_get_build_id into libJiri Olsa1-139/+4
Moving stack_map_get_build_id into lib with declaration in linux/buildid.h header: int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id); This function returns build id for given struct vm_area_struct. There is no functional change to stack_map_get_build_id function. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210114134044.1418404-2-jolsa@kernel.org
2021-01-15bpf: Add bitwise atomic instructionsBrendan Jackman3-4/+26
This adds instructions for atomic[64]_[fetch_]and atomic[64]_[fetch_]or atomic[64]_[fetch_]xor All these operations are isomorphic enough to implement with the same verifier, interpreter, and x86 JIT code, hence being a single commit. The main interesting thing here is that x86 doesn't directly support the fetch_ version these operations, so we need to generate a CMPXCHG loop in the JIT. This requires the use of two temporary registers, IIUC it's safe to use BPF_REG_AX and x86's AUX_REG for this purpose. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-10-jackmanb@google.com
2021-01-15bpf: Pull out a macro for interpreting atomic ALU operationsBrendan Jackman1-41/+39
Since the atomic operations that are added in subsequent commits are all isomorphic with BPF_ADD, pull out a macro to avoid the interpreter becoming dominated by lines of atomic-related code. Note that this sacrificies interpreter performance (combining STX_ATOMIC_W and STX_ATOMIC_DW into single switch case means that we need an extra conditional branch to differentiate them) in favour of compact and (relatively!) simple C code. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-9-jackmanb@google.com
2021-01-15bpf: Add instructions for atomic_[cmp]xchgBrendan Jackman3-2/+52
This adds two atomic opcodes, both of which include the BPF_FETCH flag. XCHG without the BPF_FETCH flag would naturally encode atomic_set. This is not supported because it would be of limited value to userspace (it doesn't imply any barriers). CMPXCHG without BPF_FETCH woulud be an atomic compare-and-write. We don't have such an operation in the kernel so it isn't provided to BPF either. There are two significant design decisions made for the CMPXCHG instruction: - To solve the issue that this operation fundamentally has 3 operands, but we only have two register fields. Therefore the operand we compare against (the kernel's API calls it 'old') is hard-coded to be R0. x86 has similar design (and A64 doesn't have this problem). A potential alternative might be to encode the other operand's register number in the immediate field. - The kernel's atomic_cmpxchg returns the old value, while the C11 userspace APIs return a boolean indicating the comparison result. Which should BPF do? A64 returns the old value. x86 returns the old value in the hard-coded register (and also sets a flag). That means return-old-value is easier to JIT, so that's what we use. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-8-jackmanb@google.com
2021-01-15bpf: Add BPF_FETCH field / create atomic_fetch_add instructionBrendan Jackman3-9/+44
The BPF_FETCH field can be set in bpf_insn.imm, for BPF_ATOMIC instructions, in order to have the previous value of the atomically-modified memory location loaded into the src register after an atomic op is carried out. Suggested-by: Yonghong Song <yhs@fb.com> Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-7-jackmanb@google.com
2021-01-15bpf: Move BPF_STX reserved field check into BPF_STX verifier codeBrendan Jackman1-7/+6
I can't find a reason why this code is in resolve_pseudo_ldimm64; since I'll be modifying it in a subsequent commit, tidy it up. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-6-jackmanb@google.com
2021-01-15bpf: Rename BPF_XADD and prepare to encode other atomics in .immBrendan Jackman3-21/+40
A subsequent patch will add additional atomic operations. These new operations will use the same opcode field as the existing XADD, with the immediate discriminating different operations. In preparation, rename the instruction mode BPF_ATOMIC and start calling the zero immediate BPF_ADD. This is possible (doesn't break existing valid BPF progs) because the immediate field is currently reserved MBZ and BPF_ADD is zero. All uses are removed from the tree but the BPF_XADD definition is kept around to avoid breaking builds for people including kernel headers. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com
2021-01-14locking/lockdep: Exclude local_lock_t from IRQ inversionsBoqun Feng1-4/+53
The purpose of local_lock_t is to abstract: preempt_disable() / local_bh_disable() / local_irq_disable(). These are the traditional means of gaining access to per-cpu data, but are fundamentally non-preemptible. local_lock_t provides a per-cpu lock, that on !PREEMPT_RT reduces to no-ops, just like regular spinlocks do on UP. This gives rise to: CPU0 CPU1 local_lock(B) spin_lock_irq(A) <IRQ> spin_lock(A) local_lock(B) Where lockdep then figures things will lock up; which would be true if B were any other kind of lock. However this is a false positive, no such deadlock actually exists. For !RT the above local_lock(B) is preempt_disable(), and there's obviously no deadlock; alternatively, CPU0's B != CPU1's B. For RT the argument is that since local_lock() nests inside spin_lock(), it cannot be used in hardirq context, and therefore CPU0 cannot in fact happen. Even though B is a real lock, it is a preemptible lock and any threaded-irq would simply schedule out and let the preempted task (which holds B) continue such that the task on CPU1 can make progress, after which the threaded-irq resumes and can finish. This means that we can never form an IRQ inversion on a local_lock dependency, so terminate the graph walk when looking for IRQ inversions when we encounter one. One consequence is that (for LOCKDEP_SMALL) when we look for redundant dependencies, A -> B is not redundant in the presence of A -> L -> B. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> [peterz: Changelog] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14locking/lockdep: Clean up check_redundant() a bitPeter Zijlstra1-42/+49
In preparation for adding an TRACE_IRQFLAGS dependent skip function to check_redundant(), move it below the TRACE_IRQFLAGS #ifdef. While there, provide a stub function to reduce #ifdef usage. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14locking/lockdep: Add a skip() function to __bfs()Boqun Feng1-10/+19
Some __bfs() walks will have additional iteration constraints (beyond the path being strong). Provide an additional function to allow terminating graph walks. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14locking/lockdep: Mark local_lock_tPeter Zijlstra1-7/+9
The local_lock_t's are special, because they cannot form IRQ inversions, make sure we can tell them apart from the rest of the locks. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14sched: Use task_current() instead of 'rq->curr == p'Hui Su4-6/+6
Use the task_current() function where appropriate. No functional change. Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20201030173223.GA52339@rlk
2021-01-14sched/fair: Reduce cases for active balanceVincent Guittot1-22/+23
Active balance is triggered for a number of voluntary cases like misfit or pinned tasks cases but also after that a number of load balance attempts failed to migrate a task. There is no need to use active load balance when the group is overloaded because an overloaded state means that there is at least one waiting task. Nevertheless, the waiting task is not selected and detached until the threshold becomes higher than its load. This threshold increases with the number of failed lb (see the condition if ((load >> env->sd->nr_balance_failed) > env->imbalance) in detach_tasks()) and the waiting task will end up to be selected after a number of attempts. 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> Acked-by: Mel Gorman <mgorman@suse.de> Link: https://lkml.kernel.org/r/20210107103325.30851-4-vincent.guittot@linaro.org
2021-01-14sched/fair: Don't set LBF_ALL_PINNED unnecessarilyVincent Guittot1-2/+5
Setting LBF_ALL_PINNED during active load balance is only valid when there is only 1 running task on the rq otherwise this ends up increasing the balance interval whereas other tasks could migrate after the next interval once they become cache-cold as an example. LBF_ALL_PINNED flag is now always set it by default. It is then cleared when we find one task that can be pulled when calling detach_tasks() or during active migration. 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> Acked-by: Mel Gorman <mgorman@suse.de> Link: https://lkml.kernel.org/r/20210107103325.30851-3-vincent.guittot@linaro.org
2021-01-14sched/fair: Skip idle cfs_rqVincent Guittot1-1/+4
Don't waste time checking whether an idle cfs_rq could be the busiest queue. Furthermore, this can end up selecting a cfs_rq with a high load but being idle in case of migrate_load. 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> Acked-by: Mel Gorman <mgorman@suse.de> Link: https://lkml.kernel.org/r/20210107103325.30851-2-vincent.guittot@linaro.org
2021-01-14sched/fair: Avoid stale CPU util_est value for schedutil in task dequeueXuewen Yan1-15/+28
CPU (root cfs_rq) estimated utilization (util_est) is currently used in dequeue_task_fair() to drive frequency selection before it is updated. with: CPU_util : rq->cfs.avg.util_avg CPU_util_est : rq->cfs.avg.util_est CPU_utilization : max(CPU_util, CPU_util_est) task_util : p->se.avg.util_avg task_util_est : p->se.avg.util_est dequeue_task_fair(): /* (1) CPU_util and task_util update + inform schedutil about CPU_utilization changes */ for_each_sched_entity() /* 2 loops */ (dequeue_entity() ->) update_load_avg() -> cfs_rq_util_change() -> cpufreq_update_util() ->...-> sugov_update_[shared\|single] -> sugov_get_util() -> cpu_util_cfs() /* (2) CPU_util_est and task_util_est update */ util_est_dequeue() cpu_util_cfs() uses CPU_utilization which could lead to a false (too high) utilization value for schedutil in task ramp-down or ramp-up scenarios during task dequeue. To mitigate the issue split the util_est update (2) into: (A) CPU_util_est update in util_est_dequeue() (B) task_util_est update in util_est_update() Place (A) before (1) and keep (B) where (2) is. The latter is necessary since (B) relies on task_util update in (1). Fixes: 7f65ea42eb00 ("sched/fair: Add util_est on top of PELT") Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/1608283672-18240-1-git-send-email-xuewen.yan94@gmail.com
2021-01-14sched: Prevent raising SCHED_SOFTIRQ when CPU is !activeAnna-Maria Behnsen2-3/+11
SCHED_SOFTIRQ is raised to trigger periodic load balancing. When CPU is not active, CPU should not participate in load balancing. The scheduler uses nohz.idle_cpus_mask to keep track of the CPUs which can do idle load balancing. When bringing a CPU up the CPU is added to the mask when it reaches the active state, but on teardown the CPU stays in the mask until it goes offline and invokes sched_cpu_dying(). When SCHED_SOFTIRQ is raised on a !active CPU, there might be a pending softirq when stopping the tick which triggers a warning in NOHZ code. The SCHED_SOFTIRQ can also be raised by the scheduler tick which has the same issue. Therefore remove the CPU from nohz.idle_cpus_mask when it is marked inactive and also prevent the scheduler_tick() from raising SCHED_SOFTIRQ after this point. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20201215104400.9435-1-anna-maria@linutronix.de
2021-01-14sched/core: Rename schedutil_cpu_util() and allow rest of the kernel to use itViresh Kumar4-11/+17
There is nothing schedutil specific in schedutil_cpu_util(), rename it to effective_cpu_util(). Also create and expose another wrapper sched_cpu_util() which can be used by other parts of the kernel, like thermal core (that will be done in a later commit). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lkml.kernel.org/r/db011961fb3bb8bef1c0eda5cd64564637d3ef31.1607400596.git.viresh.kumar@linaro.org
2021-01-14sched/core: Move schedutil_cpu_util() to core.cViresh Kumar3-117/+109
There is nothing schedutil specific in schedutil_cpu_util(), move it to core.c and define it only for CONFIG_SMP. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lkml.kernel.org/r/c921a362c78e1324f8ebc5aaa12f53e309c5a8a2.1607400596.git.viresh.kumar@linaro.org
2021-01-14bpf: Support PTR_TO_MEM{,_OR_NULL} register spillingGilad Reti1-0/+2
Add support for pointer to mem register spilling, to allow the verifier to track pointers to valid memory addresses. Such pointers are returned for example by a successful call of the bpf_ringbuf_reserve helper. The patch was partially contributed by CyberArk Software, Inc. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Suggested-by: Yonghong Song <yhs@fb.com> Signed-off-by: Gilad Reti <gilad.reti@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210113053810.13518-1-gilad.reti@gmail.com
2021-01-13genirq: Export irq_check_status_bit()Thomas Gleixner1-0/+1
One of the users can be built modular: ERROR: modpost: "irq_check_status_bit" [drivers/perf/arm_spe_pmu.ko] undefined! Fixes: fdd029630434 ("genirq: Move status flag checks to core") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201227192049.GA195845@roeck-us.net