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2017-08-18bpf: Fix map-in-map checking in the verifierMartin KaFai Lau1-0/+1
In check_map_func_compatibility(), a 'break' has been accidentally removed for the BPF_MAP_TYPE_ARRAY_OF_MAPS and BPF_MAP_TYPE_HASH_OF_MAPS cases. This patch adds it back. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18bpf: fix a return in sockmap_get_from_fd()Dan Carpenter1-2/+2
"map" is a valid pointer. We wanted to return "err" instead. Also let's return a zero literal at the end. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-17bpf: don't enable preemption twice in smap_do_verdictDaniel Borkmann1-1/+2
In smap_do_verdict(), the fall-through branch leads to call preempt_enable() twice for the SK_REDIRECT, which creates an imbalance. Only enable it for all remaining cases again. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-17bpf: fix liveness propagation to parent in spilled stack slotsDaniel Borkmann1-1/+1
Using parent->regs[] when propagating REG_LIVE_READ for spilled regs doesn't work since parent->regs[] denote the set of normal registers but not spilled ones. Propagate to the correct regs. Fixes: dc503a8ad984 ("bpf/verifier: track liveness for pruning") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16bpf: sock_map fixes for !CONFIG_BPF_SYSCALL and !STREAM_PARSERJohn Fastabend2-1/+5
Resolve issues with !CONFIG_BPF_SYSCALL and !STREAM_PARSER net/core/filter.c: In function ‘do_sk_redirect_map’: net/core/filter.c:1881:3: error: implicit declaration of function ‘__sock_map_lookup_elem’ [-Werror=implicit-function-declaration] sk = __sock_map_lookup_elem(ri->map, ri->ifindex); ^ net/core/filter.c:1881:6: warning: assignment makes pointer from integer without a cast [enabled by default] sk = __sock_map_lookup_elem(ri->map, ri->ifindex); Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16bpf: sockmap state change warning fixJohn Fastabend1-0/+3
psock will uninitialized in default case we need to do the same psock lookup and check as in other branch. Fixes compile warning below. kernel/bpf/sockmap.c: In function ‘smap_state_change’: kernel/bpf/sockmap.c:156:21: warning: ‘psock’ may be used uninitialized in this function [-Wmaybe-uninitialized] struct smap_psock *psock; Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Reported-by: David Miller <davem@davemloft.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16bpf: devmap: remove unnecessary value size checkJohn Fastabend1-6/+0
In the devmap alloc map logic we check to ensure that the sizeof the values are not greater than KMALLOC_MAX_SIZE. But, in the dev map case we ensure the value size is 4bytes earlier in the function because all values should be netdev ifindex values. The second check is harmless but is not needed so remove it. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16bpf: add access to sock fields and pkt data from sk_skb programsJohn Fastabend1-0/+1
Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16bpf: sockmap with sk redirect supportJohn Fastabend4-2/+857
Recently we added a new map type called dev map used to forward XDP packets between ports (6093ec2dc313). This patches introduces a similar notion for sockets. A sockmap allows users to add participating sockets to a map. When sockets are added to the map enough context is stored with the map entry to use the entry with a new helper bpf_sk_redirect_map(map, key, flags) This helper (analogous to bpf_redirect_map in XDP) is given the map and an entry in the map. When called from a sockmap program, discussed below, the skb will be sent on the socket using skb_send_sock(). With the above we need a bpf program to call the helper from that will then implement the send logic. The initial site implemented in this series is the recv_sock hook. For this to work we implemented a map attach command to add attributes to a map. In sockmap we add two programs a parse program and a verdict program. The parse program uses strparser to build messages and pass them to the verdict program. The parse programs use the normal strparser semantics. The verdict program is of type SK_SKB. The verdict program returns a verdict SK_DROP, or SK_REDIRECT for now. Additional actions may be added later. When SK_REDIRECT is returned, expected when bpf program uses bpf_sk_redirect_map(), the sockmap logic will consult per cpu variables set by the helper routine and pull the sock entry out of the sock map. This pattern follows the existing redirect logic in cls and xdp programs. This gives the flow, recv_sock -> str_parser (parse_prog) -> verdict_prog -> skb_send_sock \ -> kfree_skb As an example use case a message based load balancer may use specific logic in the verdict program to select the sock to send on. Sample programs are provided in future patches that hopefully illustrate the user interfaces. Also selftests are in follow-on patches. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16bpf: export bpf_prog_inc_not_zeroJohn Fastabend1-1/+2
bpf_prog_inc_not_zero will be used by upcoming sockmap patches this patch simply exports it so we can pull it in. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-6/+32
2017-08-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-4/+30
Pull networking fixes from David Miller: 1) Fix TCP checksum offload handling in iwlwifi driver, from Emmanuel Grumbach. 2) In ksz DSA tagging code, free SKB if skb_put_padto() fails. From Vivien Didelot. 3) Fix two regressions with bonding on wireless, from Andreas Born. 4) Fix build when busypoll is disabled, from Daniel Borkmann. 5) Fix copy_linear_skb() wrt. SO_PEEK_OFF, from Eric Dumazet. 6) Set SKB cached route properly in inet_rtm_getroute(), from Florian Westphal. 7) Fix PCI-E relaxed ordering handling in cxgb4 driver, from Ding Tianhong. 8) Fix module refcnt leak in ULP code, from Sabrina Dubroca. 9) Fix use of GFP_KERNEL in atomic contexts in AF_KEY code, from Eric Dumazet. 10) Need to purge socket write queue in dccp_destroy_sock(), also from Eric Dumazet. 11) Make bpf_trace_printk() work properly on 32-bit architectures, from Daniel Borkmann. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (47 commits) bpf: fix bpf_trace_printk on 32 bit archs PCI: fix oops when try to find Root Port for a PCI device sfc: don't try and read ef10 data on non-ef10 NIC net_sched: remove warning from qdisc_hash_add net_sched/sfq: update hierarchical backlog when drop packet net_sched: reset pointers to tcf blocks in classful qdiscs' destructors ipv4: fix NULL dereference in free_fib_info_rcu() net: Fix a typo in comment about sock flags. ipv6: fix NULL dereference in ip6_route_dev_notify() tcp: fix possible deadlock in TCP stack vs BPF filter dccp: purge write queue in dccp_destroy_sock() udp: fix linear skb reception with PEEK_OFF ipv6: release rt6->rt6i_idev properly during ifdown af_key: do not use GFP_KERNEL in atomic contexts tcp: ulp: avoid module refcnt leak in tcp_set_ulp net/cxgb4vf: Use new PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag net/cxgb4: Use new PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag PCI: Disable Relaxed Ordering Attributes for AMD A1100 PCI: Disable Relaxed Ordering for some Intel processors PCI: Disable PCIe Relaxed Ordering if unsupported ...
2017-08-15bpf: fix bpf_trace_printk on 32 bit archsDaniel Borkmann1-4/+30
James reported that on MIPS32 bpf_trace_printk() is currently broken while MIPS64 works fine: bpf_trace_printk() uses conditional operators to attempt to pass different types to __trace_printk() depending on the format operators. This doesn't work as intended on 32-bit architectures where u32 and long are passed differently to u64, since the result of C conditional operators follows the "usual arithmetic conversions" rules, such that the values passed to __trace_printk() will always be u64 [causing issues later in the va_list handling for vscnprintf()]. For example the samples/bpf/tracex5 test printed lines like below on MIPS32, where the fd and buf have come from the u64 fd argument, and the size from the buf argument: [...] 1180.941542: 0x00000001: write(fd=1, buf= (null), size=6258688) Instead of this: [...] 1625.616026: 0x00000001: write(fd=1, buf=009e4000, size=512) One way to get it working is to expand various combinations of argument types into 8 different combinations for 32 bit and 64 bit kernels. Fix tested by James on MIPS32 and MIPS64 as well that it resolves the issue. Fixes: 9c959c863f82 ("tracing: Allow BPF programs to call bpf_trace_printk()") Reported-by: James Hogan <james.hogan@imgtec.com> Tested-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15bpf/verifier: track liveness for pruningEdward Cree1-43/+146
State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for some Cilium programs: Program before after bpf_lb_opt_-DLB_L3.o 6515 3361 bpf_lb_opt_-DLB_L4.o 8976 5176 bpf_lb_opt_-DUNKNOWN.o 2960 1137 bpf_lxc_opt_-DDROP_ALL.o 95412 48537 bpf_lxc_opt_-DUNKNOWN.o 141706 78718 bpf_netdev.o 24251 17995 bpf_overlay.o 10999 9385 The runtime is also improved; here are 'time' results in ms: Program before after bpf_lb_opt_-DLB_L3.o 24 6 bpf_lb_opt_-DLB_L4.o 26 11 bpf_lb_opt_-DUNKNOWN.o 11 2 bpf_lxc_opt_-DDROP_ALL.o 1288 139 bpf_lxc_opt_-DUNKNOWN.o 1768 234 bpf_netdev.o 62 31 bpf_overlay.o 15 13 Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10mm: migrate: prevent racy access to tlb_flush_pendingNadav Amit1-1/+1
Patch series "fixes of TLB batching races", v6. It turns out that Linux TLB batching mechanism suffers from various races. Races that are caused due to batching during reclamation were recently handled by Mel and this patch-set deals with others. The more fundamental issue is that concurrent updates of the page-tables allow for TLB flushes to be batched on one core, while another core changes the page-tables. This other core may assume a PTE change does not require a flush based on the updated PTE value, while it is unaware that TLB flushes are still pending. This behavior affects KSM (which may result in memory corruption) and MADV_FREE and MADV_DONTNEED (which may result in incorrect behavior). A proof-of-concept can easily produce the wrong behavior of MADV_DONTNEED. Memory corruption in KSM is harder to produce in practice, but was observed by hacking the kernel and adding a delay before flushing and replacing the KSM page. Finally, there is also one memory barrier missing, which may affect architectures with weak memory model. This patch (of 7): Setting and clearing mm->tlb_flush_pending can be performed by multiple threads, since mmap_sem may only be acquired for read in task_numa_work(). If this happens, tlb_flush_pending might be cleared while one of the threads still changes PTEs and batches TLB flushes. This can lead to the same race between migration and change_protection_range() that led to the introduction of tlb_flush_pending. The result of this race was data corruption, which means that this patch also addresses a theoretically possible data corruption. An actual data corruption was not observed, yet the race was was confirmed by adding assertion to check tlb_flush_pending is not set by two threads, adding artificial latency in change_protection_range() and using sysctl to reduce kernel.numa_balancing_scan_delay_ms. Link: http://lkml.kernel.org/r/20170802000818.4760-2-namit@vmware.com Fixes: 20841405940e ("mm: fix TLB flush race between migration, and change_protection_range") Signed-off-by: Nadav Amit <namit@vmware.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Russell King <linux@armlinux.org.uk> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-10mm: fix global NR_SLAB_.*CLAIMABLE counter readsJohannes Weiner1-1/+1
As Tetsuo points out: "Commit 385386cff4c6 ("mm: vmstat: move slab statistics from zone to node counters") broke "Slab:" field of /proc/meminfo . It shows nearly 0kB" In addition to /proc/meminfo, this problem also affects the slab counters OOM/allocation failure info dumps, can cause early -ENOMEM from overcommit protection, and miscalculate image size requirements during suspend-to-disk. This is because the patch in question switched the slab counters from the zone level to the node level, but forgot to update the global accessor functions to read the aggregate node data instead of the aggregate zone data. Use global_node_page_state() to access the global slab counters. Fixes: 385386cff4c6 ("mm: vmstat: move slab statistics from zone to node counters") Link: http://lkml.kernel.org/r/20170801134256.5400-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Stefan Agner <stefan@agner.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-09bpf: enable BPF_J{LT, LE, SLT, SLE} opcodes in verifierDaniel Borkmann1-4/+58
Enable the newly added jump opcodes, main parts are in two different areas, namely direct packet access and dynamic map value access. For the direct packet access, we now allow for the following two new patterns to match in order to trigger markings with find_good_pkt_pointers(): Variant 1 (access ok when taking the branch): 0: (61) r2 = *(u32 *)(r1 +76) 1: (61) r3 = *(u32 *)(r1 +80) 2: (bf) r0 = r2 3: (07) r0 += 8 4: (ad) if r0 < r3 goto pc+2 R0=pkt(id=0,off=8,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R10=fp 5: (b7) r0 = 0 6: (95) exit from 4 to 7: R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R10=fp 7: (71) r0 = *(u8 *)(r2 +0) 8: (05) goto pc-4 5: (b7) r0 = 0 6: (95) exit processed 11 insns, stack depth 0 Variant 2 (access ok on fall-through): 0: (61) r2 = *(u32 *)(r1 +76) 1: (61) r3 = *(u32 *)(r1 +80) 2: (bf) r0 = r2 3: (07) r0 += 8 4: (bd) if r3 <= r0 goto pc+1 R0=pkt(id=0,off=8,r=8) R1=ctx R2=pkt(id=0,off=0,r=8) R3=pkt_end R10=fp 5: (71) r0 = *(u8 *)(r2 +0) 6: (b7) r0 = 1 7: (95) exit from 4 to 6: R0=pkt(id=0,off=8,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R10=fp 6: (b7) r0 = 1 7: (95) exit processed 10 insns, stack depth 0 The above two basically just swap the branches where we need to handle an exception and allow packet access compared to the two already existing variants for find_good_pkt_pointers(). For the dynamic map value access, we add the new instructions to reg_set_min_max() and reg_set_min_max_inv() in order to learn bounds. Verifier test cases for both are added in a follow-up patch. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-09bpf: add BPF_J{LT,LE,SLT,SLE} instructionsDaniel Borkmann1-0/+60
Currently, eBPF only understands BPF_JGT (>), BPF_JGE (>=), BPF_JSGT (s>), BPF_JSGE (s>=) instructions, this means that particularly *JLT/*JLE counterparts involving immediates need to be rewritten from e.g. X < [IMM] by swapping arguments into [IMM] > X, meaning the immediate first is required to be loaded into a register Y := [IMM], such that then we can compare with Y > X. Note that the destination operand is always required to be a register. This has the downside of having unnecessarily increased register pressure, meaning complex program would need to spill other registers temporarily to stack in order to obtain an unused register for the [IMM]. Loading to registers will thus also affect state pruning since we need to account for that register use and potentially those registers that had to be spilled/filled again. As a consequence slightly more stack space might have been used due to spilling, and BPF programs are a bit longer due to extra code involving the register load and potentially required spill/fills. Thus, add BPF_JLT (<), BPF_JLE (<=), BPF_JSLT (s<), BPF_JSLE (s<=) counterparts to the eBPF instruction set. Modifying LLVM to remove the NegateCC() workaround in a PoC patch at [1] and allowing it to also emit the new instructions resulted in cilium's BPF programs that are injected into the fast-path to have a reduced program length in the range of 2-3% (e.g. accumulated main and tail call sections from one of the object file reduced from 4864 to 4729 insns), reduced complexity in the range of 10-30% (e.g. accumulated sections reduced in one of the cases from 116432 to 88428 insns), and reduced stack usage in the range of 1-5% (e.g. accumulated sections from one of the object files reduced from 824 to 784b). The modification for LLVM will be incorporated in a backwards compatible way. Plan is for LLVM to have i) a target specific option to offer a possibility to explicitly enable the extension by the user (as we have with -m target specific extensions today for various CPU insns), and ii) have the kernel checked for presence of the extensions and enable them transparently when the user is selecting more aggressive options such as -march=native in a bpf target context. (Other frontends generating BPF byte code, e.g. ply can probe the kernel directly for its code generation.) [1] https://github.com/borkmann/llvm/tree/bpf-insns Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+3
The UDP offload conflict is dealt with by simply taking what is in net-next where we have removed all of the UFO handling code entirely. The TCP conflict was a case of local variables in a function being removed from both net and net-next. In netvsc we had an assignment right next to where a missing set of u64 stats sync object inits were added. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-09futex: Remove unnecessary warning from get_futex_keyMel Gorman1-2/+3
Commit 65d8fc777f6d ("futex: Remove requirement for lock_page() in get_futex_key()") removed an unnecessary lock_page() with the side-effect that page->mapping needed to be treated very carefully. Two defensive warnings were added in case any assumption was missed and the first warning assumed a correct application would not alter a mapping backing a futex key. Since merging, it has not triggered for any unexpected case but Mark Rutland reported the following bug triggering due to the first warning. kernel BUG at kernel/futex.c:679! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3 Hardware name: linux,dummy-virt (DT) task: ffff80001e271780 task.stack: ffff000010908000 PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679 LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679 pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145 The fact that it's a bug instead of a warning was due to an unrelated arm64 problem, but the warning itself triggered because the underlying mapping changed. This is an application issue but from a kernel perspective it's a recoverable situation and the warning is unnecessary so this patch removes the warning. The warning may potentially be triggered with the following test program from Mark although it may be necessary to adjust NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the system. #include <linux/futex.h> #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <sys/syscall.h> #include <sys/time.h> #include <unistd.h> #define NR_FUTEX_THREADS 16 pthread_t threads[NR_FUTEX_THREADS]; void *mem; #define MEM_PROT (PROT_READ | PROT_WRITE) #define MEM_SIZE 65536 static int futex_wrapper(int *uaddr, int op, int val, const struct timespec *timeout, int *uaddr2, int val3) { syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3); } void *poll_futex(void *unused) { for (;;) { futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1); } } int main(int argc, char *argv[]) { int i; mem = mmap(NULL, MEM_SIZE, MEM_PROT, MAP_SHARED | MAP_ANONYMOUS, -1, 0); printf("Mapping @ %p\n", mem); printf("Creating futex threads...\n"); for (i = 0; i < NR_FUTEX_THREADS; i++) pthread_create(&threads[i], NULL, poll_futex, NULL); printf("Flipping mapping...\n"); for (;;) { mmap(mem, MEM_SIZE, MEM_PROT, MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0); } return 0; } Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org # 4.7+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-08bpf: Extend check_uarg_tail_zero() checksMickaël Salaün1-11/+15
The function check_uarg_tail_zero() was created from bpf(2) for BPF_OBJ_GET_INFO_BY_FD without taking the access_ok() nor the PAGE_SIZE checks. Make this checks more generally available while unlikely to be triggered, extend the memory range check and add an explanation including why the ToCToU should not be a security concern. Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Kees Cook <keescook@chromium.org> Cc: Martin KaFai Lau <kafai@fb.com> Link: https://lkml.kernel.org/r/CAGXu5j+vRGFvJZmjtAcT8Hi8B+Wz0e1b6VKYZHfQP_=DXzC4CQ@mail.gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-08bpf: Move check_uarg_tail_zero() upwardMickaël Salaün1-26/+26
The function check_uarg_tail_zero() may be useful for other part of the code in the syscall.c file. Move this function at the beginning of the file. Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Kees Cook <keescook@chromium.org> Cc: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-08bpf/verifier: increase complexity limit to 128kEdward Cree1-1/+1
The more detailed value tracking can reduce the effectiveness of pruning for some programs. So, to avoid rejecting previously valid programs, up the limit to 128kinsns. Hopefully we will be able to bring this back down later by improving pruning performance. Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-08bpf/verifier: more concise register state logs for constant var_offEdward Cree1-19/+27
Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-08bpf/verifier: track signed and unsigned min/max valuesEdward Cree2-308/+445
Allows us to, sometimes, combine information from a signed check of one bound and an unsigned check of the other. We now track the full range of possible values, rather than restricting ourselves to [0, 1<<30) and considering anything beyond that as unknown. While this is probably not necessary, it makes the code more straightforward and symmetrical between signed and unsigned bounds. Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-08bpf/verifier: rework value trackingEdward Cree3-807/+1139
Unifies adjusted and unadjusted register value types (e.g. FRAME_POINTER is now just a PTR_TO_STACK with zero offset). Tracks value alignment by means of tracking known & unknown bits. This also replaces the 'reg->imm' (leading zero bits) calculations for (what were) UNKNOWN_VALUEs. If pointer leaks are allowed, and adjust_ptr_min_max_vals returns -EACCES, treat the pointer as an unknown scalar and try again, because we might be able to conclude something about the result (e.g. pointer & 0x40 is either 0 or 0x40). Verifier hooks in the netronome/nfp driver were changed to match the new data structures. Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07bpf: devmap fix mutex in rcu critical sectionJohn Fastabend1-23/+25
Originally we used a mutex to protect concurrent devmap update and delete operations from racing with netdev unregister notifier callbacks. The notifier hook is needed because we increment the netdev ref count when a dev is added to the devmap. This ensures the netdev reference is valid in the datapath. However, we don't want to block unregister events, hence the initial mutex and notifier handler. The concern was in the notifier hook we search the map for dev entries that hold a refcnt on the net device being torn down. But, in order to do this we require two steps, (i) dereference the netdev: dev = rcu_dereference(map[i]) (ii) test ifindex: dev->ifindex == removing_ifindex and then finally we can swap in the NULL dev in the map via an xchg operation, xchg(map[i], NULL) The danger here is a concurrent update could run a different xchg op concurrently leading us to replace the new dev with a NULL dev incorrectly. CPU 1 CPU 2 notifier hook bpf devmap update dev = rcu_dereference(map[i]) dev = rcu_dereference(map[i]) xchg(map[i]), new_dev); rcu_call(dev,...) xchg(map[i], NULL) The above flow would create the incorrect state with the dev reference in the update path being lost. To resolve this the original code used a mutex around the above block. However, updates, deletes, and lookups occur inside rcu critical sections so we can't use a mutex in this context safely. Fortunately, by writing slightly better code we can avoid the mutex altogether. If CPU 1 in the above example uses a cmpxchg and _only_ replaces the dev reference in the map when it is in fact the expected dev the race is removed completely. The two cases being illustrated here, first the race condition, CPU 1 CPU 2 notifier hook bpf devmap update dev = rcu_dereference(map[i]) dev = rcu_dereference(map[i]) xchg(map[i]), new_dev); rcu_call(dev,...) odev = cmpxchg(map[i], dev, NULL) Now we can test the cmpxchg return value, detect odev != dev and abort. Or in the good case, CPU 1 CPU 2 notifier hook bpf devmap update dev = rcu_dereference(map[i]) odev = cmpxchg(map[i], dev, NULL) [...] Now 'odev == dev' and we can do proper cleanup. And viola the original race we tried to solve with a mutex is corrected and the trace noted by Sasha below is resolved due to removal of the mutex. Note: When walking the devmap and removing dev references as needed we depend on the core to fail any calls to dev_get_by_index() using the ifindex of the device being removed. This way we do not race with the user while searching the devmap. Additionally, the mutex was also protecting list add/del/read on the list of maps in-use. This patch converts this to an RCU list and spinlock implementation. This protects the list from concurrent alloc/free operations. The notifier hook walks this list so it uses RCU read semantics. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 in_atomic(): 1, irqs_disabled(): 0, pid: 16315, name: syz-executor1 1 lock held by syz-executor1/16315: #0: (rcu_read_lock){......}, at: [<ffffffff8c363bc2>] map_delete_elem kernel/bpf/syscall.c:577 [inline] #0: (rcu_read_lock){......}, at: [<ffffffff8c363bc2>] SYSC_bpf kernel/bpf/syscall.c:1427 [inline] #0: (rcu_read_lock){......}, at: [<ffffffff8c363bc2>] SyS_bpf+0x1d32/0x4ba0 kernel/bpf/syscall.c:1388 Fixes: 2ddf71e23cc2 ("net: add notifier hooks for devmap bpf map") Reported-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07bpf: add support for sys_enter_* and sys_exit_* tracepointsYonghong Song2-6/+57
Currently, bpf programs cannot be attached to sys_enter_* and sys_exit_* style tracepoints. The iovisor/bcc issue #748 (https://github.com/iovisor/bcc/issues/748) documents this issue. For example, if you try to attach a bpf program to tracepoints syscalls/sys_enter_newfstat, you will get the following error: # ./tools/trace.py t:syscalls:sys_enter_newfstat Ioctl(PERF_EVENT_IOC_SET_BPF): Invalid argument Failed to attach BPF to tracepoint The main reason is that syscalls/sys_enter_* and syscalls/sys_exit_* tracepoints are treated differently from other tracepoints and there is no bpf hook to it. This patch adds bpf support for these syscalls tracepoints by . permitting bpf attachment in ioctl PERF_EVENT_IOC_SET_BPF . calling bpf programs in perf_syscall_enter and perf_syscall_exit The legality of bpf program ctx access is also checked. Function trace_event_get_offsets returns correct max offset for each specific syscall tracepoint, which is compared against the maximum offset access in bpf program. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07Merge tag 'mlx5-shared-2017-08-07' of ↵David S. Miller4-8/+9
git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux Saeed Mahameed says: ==================== mlx5-shared-2017-08-07 This series includes some mlx5 updates for both net-next and rdma trees. From Saeed, Core driver updates to allow selectively building the driver with or without some large driver components, such as - E-Switch (Ethernet SRIOV support). - Multi-Physical Function Switch (MPFs) support. For that we split E-Switch and MPFs functionalities into separate files. From Erez, Delay mlx5_core events when mlx5 interfaces, namely mlx5_ib, registration is taking place and until it completes. From Rabie, Increase the maximum supported flow counters. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06Fix compat_sys_sigpending breakageDmitry V. Levin1-4/+7
The latest change of compat_sys_sigpending in commit 8f13621abced ("sigpending(): move compat to native") has broken it in two ways. First, it tries to write 4 bytes more than userspace expects: sizeof(old_sigset_t) == sizeof(long) == 8 instead of sizeof(compat_old_sigset_t) == sizeof(u32) == 4. Second, on big endian architectures these bytes are being written in the wrong order. This bug was found by strace test suite. Reported-by: Anatoly Pugachev <matorola@gmail.com> Inspired-by: Eugene Syromyatnikov <evgsyr@gmail.com> Fixes: 8f13621abced ("sigpending(): move compat to native") Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-04Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single fix for a multiplication overflow in the timer code on 32bit systems" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Fix overflow in get_next_timer_interrupt
2017-08-02cpuset: fix a deadlock due to incomplete patching of cpusets_enabled()Dima Zavin1-0/+1
In codepaths that use the begin/retry interface for reading mems_allowed_seq with irqs disabled, there exists a race condition that stalls the patch process after only modifying a subset of the static_branch call sites. This problem manifested itself as a deadlock in the slub allocator, inside get_any_partial. The loop reads mems_allowed_seq value (via read_mems_allowed_begin), performs the defrag operation, and then verifies the consistency of mem_allowed via the read_mems_allowed_retry and the cookie returned by xxx_begin. The issue here is that both begin and retry first check if cpusets are enabled via cpusets_enabled() static branch. This branch can be rewritted dynamically (via cpuset_inc) if a new cpuset is created. The x86 jump label code fully synchronizes across all CPUs for every entry it rewrites. If it rewrites only one of the callsites (specifically the one in read_mems_allowed_retry) and then waits for the smp_call_function(do_sync_core) to complete while a CPU is inside the begin/retry section with IRQs off and the mems_allowed value is changed, we can hang. This is because begin() will always return 0 (since it wasn't patched yet) while retry() will test the 0 against the actual value of the seq counter. The fix is to use two different static keys: one for begin (pre_enable_key) and one for retry (enable_key). In cpuset_inc(), we first bump the pre_enable key to ensure that cpuset_mems_allowed_begin() always return a valid seqcount if are enabling cpusets. Similarly, when disabling cpusets via cpuset_dec(), we first ensure that callers of cpuset_mems_allowed_retry() will start ignoring the seqcount value before we let cpuset_mems_allowed_begin() return 0. The relevant stack traces of the two stuck threads: CPU: 1 PID: 1415 Comm: mkdir Tainted: G L 4.9.36-00104-g540c51286237 #4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8817f9c28000 task.stack: ffffc9000ffa4000 RIP: smp_call_function_many+0x1f9/0x260 Call Trace: smp_call_function+0x3b/0x70 on_each_cpu+0x2f/0x90 text_poke_bp+0x87/0xd0 arch_jump_label_transform+0x93/0x100 __jump_label_update+0x77/0x90 jump_label_update+0xaa/0xc0 static_key_slow_inc+0x9e/0xb0 cpuset_css_online+0x70/0x2e0 online_css+0x2c/0xa0 cgroup_apply_control_enable+0x27f/0x3d0 cgroup_mkdir+0x2b7/0x420 kernfs_iop_mkdir+0x5a/0x80 vfs_mkdir+0xf6/0x1a0 SyS_mkdir+0xb7/0xe0 entry_SYSCALL_64_fastpath+0x18/0xad ... CPU: 2 PID: 1 Comm: init Tainted: G L 4.9.36-00104-g540c51286237 #4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8818087c0000 task.stack: ffffc90000030000 RIP: int3+0x39/0x70 Call Trace: <#DB> ? ___slab_alloc+0x28b/0x5a0 <EOE> ? copy_process.part.40+0xf7/0x1de0 __slab_alloc.isra.80+0x54/0x90 copy_process.part.40+0xf7/0x1de0 copy_process.part.40+0xf7/0x1de0 kmem_cache_alloc_node+0x8a/0x280 copy_process.part.40+0xf7/0x1de0 _do_fork+0xe7/0x6c0 _raw_spin_unlock_irq+0x2d/0x60 trace_hardirqs_on_caller+0x136/0x1d0 entry_SYSCALL_64_fastpath+0x5/0xad do_syscall_64+0x27/0x350 SyS_clone+0x19/0x20 do_syscall_64+0x60/0x350 entry_SYSCALL64_slow_path+0x25/0x25 Link: http://lkml.kernel.org/r/20170731040113.14197-1-dmitriyz@waymo.com Fixes: 46e700abc44c ("mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled") Signed-off-by: Dima Zavin <dmitriyz@waymo.com> Reported-by: Cliff Spradlin <cspradlin@waymo.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christopher Lameter <cl@linux.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-02pid: kill pidhash_size in pidhash_init()Kefeng Wang1-3/+0
After commit 3d375d78593c ("mm: update callers to use HASH_ZERO flag"), drop unused pidhash_size in pidhash_init(). Link: http://lkml.kernel.org/r/1500389267-49222-1-git-send-email-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Pavel Tatashin <Pasha.Tatashin@Oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller18-107/+162
Two minor conflicts in virtio_net driver (bug fix overlapping addition of a helper) and MAINTAINERS (new driver edit overlapping revamp of PHY entry). Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-01timers: Fix overflow in get_next_timer_interruptMatija Glavinic Pecotic1-1/+1
For e.g. HZ=100, timer being 430 jiffies in the future, and 32 bit unsigned int, there is an overflow on unsigned int right-hand side of the expression which results with wrong values being returned. Type cast the multiplier to 64bit to avoid that issue. Fixes: 46c8f0b077a8 ("timers: Fix get_next_timer_interrupt() computation") Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Cc: khilman@baylibre.com Cc: akpm@linux-foundation.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/a7900f04-2a21-c9fd-67be-ab334d459ee5@nokia.com
2017-07-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2-8/+17
Pull networking fixes from David Miller: 1) Handle notifier registry failures properly in tun/tap driver, from Tonghao Zhang. 2) Fix bpf verifier handling of subtraction bounds and add a testcase for this, from Edward Cree. 3) Increase reset timeout in ftgmac100 driver, from Ben Herrenschmidt. 4) Fix use after free in prd_retire_rx_blk_timer_exired() in AF_PACKET, from Cong Wang. 5) Fix SElinux regression due to recent UDP optimizations, from Paolo Abeni. 6) We accidently increment IPSTATS_MIB_FRAGFAILS in the ipv6 code paths, fix from Stefano Brivio. 7) Fix some mem leaks in dccp, from Xin Long. 8) Adjust MDIO_BUS kconfig deps to avoid build errors, from Arnd Bergmann. 9) Mac address length check and buffer size fixes from Cong Wang. 10) Don't leak sockets in ipv6 udp early demux, from Paolo Abeni. 11) Fix return value when copy_from_user() fails in bpf_prog_get_info_by_fd(), from Daniel Borkmann. 12) Handle PHY_HALTED properly in phy library state machine, from Florian Fainelli. 13) Fix OOPS in fib_sync_down_dev(), from Ido Schimmel. 14) Fix truesize calculation in virtio_net which led to performance regressions, from Michael S Tsirkin. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits) samples/bpf: fix bpf tunnel cleanup udp6: fix jumbogram reception ppp: Fix a scheduling-while-atomic bug in del_chan Revert "net: bcmgenet: Remove init parameter from bcmgenet_mii_config" virtio_net: fix truesize for mergeable buffers mv643xx_eth: fix of_irq_to_resource() error check MAINTAINERS: Add more files to the PHY LIBRARY section ipv4: fib: Fix NULL pointer deref during fib_sync_down_dev() net: phy: Correctly process PHY_HALTED in phy_stop_machine() sunhme: fix up GREG_STAT and GREG_IMASK register offsets bpf: fix bpf_prog_get_info_by_fd to dump correct xlated_prog_len tcp: avoid bogus gcc-7 array-bounds warning net: tc35815: fix spelling mistake: "Intterrupt" -> "Interrupt" bpf: don't indicate success when copy_from_user fails udp6: fix socket leak on early demux net: thunderx: Fix BGX transmit stall due to underflow Revert "vhost: cache used event for better performance" team: use a larger struct for mac address net: check dev->addr_len for dev_set_mac_address() phy: bcm-ns-usb3: fix MDIO_BUS dependency ...
2017-07-31Merge branch 'for-4.13-fixes' of ↵Linus Torvalds2-29/+40
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "Several cgroup bug fixes. - cgroup core was calling a migration callback on empty migrations, which could make cpuset crash. - There was a very subtle bug where the controller interface files aren't created directly when cgroup2 is mounted. Because later operations create them, this bug didn't get noticed earlier. - Failed writes to cgroup.subtree_control were incorrectly returning zero" * 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix error return value from cgroup_subtree_control() cgroup: create dfl_root files on subsys registration cgroup: don't call migration methods if there are no tasks to migrate
2017-07-31Merge branch 'for-4.13-fixes' of ↵Linus Torvalds1-4/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: "Two notable fixes. - While adding NUMA affinity support to unbound workqueues, the assumption that an unbound workqueue with max_active == 1 is ordered was broken. The plan was to use explicit alloc_ordered_workqueue() for those cases. Unfortunately, I forgot to update the documentation properly and we grew a handful of use cases which depend on that assumption. While we want to convert them to alloc_ordered_workqueue(), we don't really lose anything by enforcing ordered execution on unbound max_active == 1 workqueues and it doesn't make sense to risk subtle bugs. Restore the assumption. - Workqueue assumes that CPU <-> NUMA node mapping remains static. This is a general assumption - we don't have any synchronization mechanism around CPU <-> node mapping. Unfortunately, powerpc may change the mapping dynamically leading to crashes. Michael added a workaround so that we at least don't crash while powerpc hotplug code gets updated" * 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Work around edge cases for calc of pool's cpumask workqueue: implicit ordered attribute should be overridable workqueue: restore WQ_UNBOUND/max_active==1 to be ordered
2017-07-30Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Two patches addressing build warnings caused by inconsistent kernel doc comments" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/wait: Clean up some documentation warnings sched/core: Fix some documentation build warnings
2017-07-29bpf: fix bpf_prog_get_info_by_fd to dump correct xlated_prog_lenDaniel Borkmann1-1/+1
bpf_prog_size(prog->len) is not the correct length we want to dump back to user space. The code in bpf_prog_get_info_by_fd() uses this to copy prog->insnsi to user space, but bpf_prog_size(prog->len) also includes the size of struct bpf_prog itself plus program instructions and is usually used either in context of accounting or for bpf_prog_alloc() et al, thus we copy out of bounds in bpf_prog_get_info_by_fd() potentially. Use the correct bpf_prog_insn_size() instead. Fixes: 1e2709769086 ("bpf: Add BPF_OBJ_GET_INFO_BY_FD") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-29bpf: don't indicate success when copy_from_user failsDaniel Borkmann1-1/+1
err in bpf_prog_get_info_by_fd() still holds 0 at that time from prior check_uarg_tail_zero() check. Explicitly return -EFAULT instead, so user space can be notified of buggy behavior. Fixes: 1e2709769086 ("bpf: Add BPF_OBJ_GET_INFO_BY_FD") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-28workqueue: Work around edge cases for calc of pool's cpumaskMichael Bringmann1-0/+7
There is an underlying assumption/trade-off in many layers of the Linux system that CPU <-> node mapping is static. This is despite the presence of features like NUMA and 'hotplug' that support the dynamic addition/ removal of fundamental system resources like CPUs and memory. PowerPC systems, however, do provide extensive features for the dynamic change of resources available to a system. Currently, there is little or no synchronization protection around the updating of the CPU <-> node mapping, and the export/update of this information for other layers / modules. In systems which can change this mapping during 'hotplug', like PowerPC, the information is changing underneath all layers that might reference it. This patch attempts to ensure that a valid, usable cpumask attribute is used by the workqueue infrastructure when setting up new resource pools. It prevents a crash that has been observed when an 'empty' cpumask is passed along to the worker/task scheduling code. It is intended as a temporary workaround until a more fundamental review and correction of the issue can be done. [With additions to the patch provided by Tejun Hao <tj@kernel.org>] Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-07-27genirq/cpuhotplug: Revert "Set force affinity flag on hotplug migration"Thomas Gleixner1-2/+7
That commit was part of the changes moving x86 to the generic CPU hotplug interrupt migration code. The force flag was required on x86 before the hierarchical irqdomain rework, but invoking set_affinity() with force=true stayed and had no side effects. At some point in the past, the force flag got repurposed to support the exynos timer interrupt affinity setting to a not yet online CPU, so the interrupt controller callback does not verify the supplied affinity mask against cpu_online_mask. Setting the flag in the CPU hotplug code causes the cpu online masking to be blocked on these irq controllers and results in potentially affining an interrupt to the CPU which is unplugged, i.e. instead of moving it away, it's just reassigned to it. As the force flags is not longer needed on x86, it's safe to revert that patch so the ARM irqchips which use the force flag work again. Add comments to that effect, so this won't happen again. Note: The online mask handling should be done in the generic code and the force flag and the masking in the irq chips removed all together, but that's not a change possible for 4.13. Fixes: 77f85e66aa8b ("genirq/cpuhotplug: Set force affinity flag on hotplug migration") Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: LAK <linux-arm-kernel@lists.infradead.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1707271217590.3109@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-07-25workqueue: implicit ordered attribute should be overridableTejun Heo1-4/+9
5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") automatically enabled ordered attribute for unbound workqueues w/ max_active == 1. Because ordered workqueues reject max_active and some attribute changes, this implicit ordered mode broke cases where the user creates an unbound workqueue w/ max_active == 1 and later explicitly changes the related attributes. This patch distinguishes explicit and implicit ordered setting and overrides from attribute changes if implict. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
2017-07-25sched/core: Fix some documentation build warningsJonathan Corbet1-1/+1
The kerneldoc comments for try_to_wake_up_local() were out of date, leading to these documentation build warnings: ./kernel/sched/core.c:2080: warning: No description found for parameter 'rf' ./kernel/sched/core.c:2080: warning: Excess function parameter 'cookie' description in 'try_to_wake_up_local' Update the comment to reflect current reality and give us some peace and quiet. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20170724135628.695cecfc@lwn.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-24bpf: dev_map_alloc() shouldn't return NULLDan Carpenter1-0/+1
We forgot to set the error code on two error paths which means that we return ERR_PTR(0) which is NULL. The caller, find_and_alloc_map(), is not expecting that and will have a NULL dereference. Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-24bpf/verifier: fix min/max handling in BPF_SUBEdward Cree1-6/+15
We have to subtract the src max from the dst min, and vice-versa, since (e.g.) the smallest result comes from the largest subtrahend. Fixes: 484611357c19 ("bpf: allow access into map value arrays") Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-23cgroup: fix error return value from cgroup_subtree_control()Tejun Heo1-2/+2
While refactoring, f7b2814bb9b6 ("cgroup: factor out cgroup_{apply|finalize}_control() from cgroup_subtree_control_write()") broke error return value from the function. The return value from the last operation is always overridden to zero. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Tejun Heo <tj@kernel.org>
2017-07-21Merge tag 'trace-v4.13-rc1' of ↵Linus Torvalds4-22/+36
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Three minor updates - Use the new GFP_RETRY_MAYFAIL to be more aggressive in allocating memory for the ring buffer without causing OOMs - Fix a memory leak in adding and removing instances - Add __rcu annotation to be able to debug RCU usage of function tracing a bit better" * tag 'trace-v4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: trace: fix the errors caused by incompatible type of RCU variables tracing: Fix kmemleak in instance_rmdir tracing/ring_buffer: Try harder to allocate
2017-07-21Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2-9/+11
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "A cputime fix and code comments/organization fix to the deadline scheduler" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix confusing comments about selection of top pi-waiter sched/cputime: Don't use smp_processor_id() in preemptible context