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2018-05-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix refcounting bug for connections in on-packet scheduling mode of IPVS, from Julian Anastasov. 2) Set network header properly in AF_PACKET's packet_snd, from Willem de Bruijn. 3) Fix regressions in 3c59x by converting to generic DMA API. It was relying upon the hack that the PCI DMA interfaces would accept NULL for EISA devices. From Christoph Hellwig. 4) Remove RDMA devices before unregistering netdev in QEDE driver, from Michal Kalderon. 5) Use after free in TUN driver ptr_ring usage, from Jason Wang. 6) Properly check for missing netlink attributes in SMC_PNETID requests, from Eric Biggers. 7) Set DMA mask before performaing any DMA operations in vmxnet3 driver, from Regis Duchesne. 8) Fix mlx5 build with SMP=n, from Saeed Mahameed. 9) Classifier fixes in bcm_sf2 driver from Florian Fainelli. 10) Tuntap use after free during release, from Jason Wang. 11) Don't use stack memory in scatterlists in tls code, from Matt Mullins. 12) Not fully initialized flow key object in ipv4 routing code, from David Ahern. 13) Various packet headroom bug fixes in ip6_gre driver, from Petr Machata. 14) Remove queues from XPS maps using correct index, from Amritha Nambiar. 15) Fix use after free in sock_diag, from Eric Dumazet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (64 commits) net: ip6_gre: fix tunnel metadata device sharing. cxgb4: fix offset in collecting TX rate limit info net: sched: red: avoid hashing NULL child sock_diag: fix use-after-free read in __sk_free sh_eth: Change platform check to CONFIG_ARCH_RENESAS net: dsa: Do not register devlink for unused ports net: Fix a bug in removing queues from XPS map bpf: fix truncated jump targets on heavy expansions bpf: parse and verdict prog attach may race with bpf map update bpf: sockmap update rollback on error can incorrectly dec prog refcnt net: test tailroom before appending to linear skb net: ip6_gre: Fix ip6erspan hlen calculation net: ip6_gre: Split up ip6gre_changelink() net: ip6_gre: Split up ip6gre_newlink() net: ip6_gre: Split up ip6gre_tnl_change() net: ip6_gre: Split up ip6gre_tnl_link_config() net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit() net: ip6_gre: Request headroom in __gre6_xmit() selftests/bpf: check return value of fopen in test_verifier.c erspan: fix invalid erspan version. ...
2018-05-21workqueue: Make sure struct worker is accessible for wq_worker_comm()Tejun Heo
The worker struct could already be freed when wq_worker_comm() tries to access it for reporting. This patch protects PF_WQ_WORKER modifications with wq_pool_attach_mutex and makes wq_worker_comm() test the flag before dereferencing worker from kthread_data(), which ensures that it only dereferences when the worker struct is valid. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Lai Jiangshan <jiangshanlai@gmail.com> Fixes: 6b59808bfe48 ("workqueue: Show the latest workqueue name in /proc/PID/{comm,stat,status}")
2018-05-20Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull UP timer fix from Thomas Gleixner: "Work around the for_each_cpu() oddity on UP kernels in the tick broadcast code which causes boot failures because the CPU0 bit is always reported as set independent of the cpumask content" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/broadcast: Use for_each_cpu() specially on UP kernels
2018-05-20Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixlets from Thomas Gleixner: "Three trivial fixlets for the scheduler: - move print_rt_rq() and print_dl_rq() declarations to the right place - make grub_reclaim() static - fix the bogus documentation reference in Kconfig" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix documentation file path sched/deadline: Make the grub_reclaim() function static sched/debug: Move the print_rt_rq() and print_dl_rq() declarations to kernel/sched/sched.h
2018-05-19bpf: Prevent memory disambiguation attackAlexei Starovoitov
Detect code patterns where malicious 'speculative store bypass' can be used and sanitize such patterns. 39: (bf) r3 = r10 40: (07) r3 += -216 41: (79) r8 = *(u64 *)(r7 +0) // slow read 42: (7a) *(u64 *)(r10 -72) = 0 // verifier inserts this instruction 43: (7b) *(u64 *)(r8 +0) = r3 // this store becomes slow due to r8 44: (79) r1 = *(u64 *)(r6 +0) // cpu speculatively executes this load 45: (71) r2 = *(u8 *)(r1 +0) // speculatively arbitrary 'load byte' // is now sanitized Above code after x86 JIT becomes: e5: mov %rbp,%rdx e8: add $0xffffffffffffff28,%rdx ef: mov 0x0(%r13),%r14 f3: movq $0x0,-0x48(%rbp) fb: mov %rdx,0x0(%r14) ff: mov 0x0(%rbx),%rdi 103: movzbq 0x0(%rdi),%rsi Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-19timekeeping: Add ktime_get_coarse_with_offsetArnd Bergmann
I have run into a couple of drivers using current_kernel_time() suffering from the y2038 problem, and they could be converted to using ktime_t, but don't have interfaces that skip the nanosecond calculation at the moment. This introduces ktime_get_coarse_with_offset() as a simpler variant of ktime_get_with_offset(), and adds wrappers for the three time domains we support with the existing function. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: y2038@lists.linaro.org Cc: John Stultz <john.stultz@linaro.org> Link: https://lkml.kernel.org/r/20180427134016.2525989-5-arnd@arndb.de
2018-05-19timekeeping: Standardize on ktime_get_*() namingArnd Bergmann
The current_kernel_time64, get_monotonic_coarse64, getrawmonotonic64, get_monotonic_boottime64 and timekeeping_clocktai64 interfaces have rather inconsistent naming, and they differ in the calling conventions by passing the output either by reference or as a return value. Rename them to ktime_get_coarse_real_ts64, ktime_get_coarse_ts64, ktime_get_raw_ts64, ktime_get_boottime_ts64 and ktime_get_clocktai_ts64 respectively, and provide the interfaces with macros or inline functions as needed. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: y2038@lists.linaro.org Cc: John Stultz <john.stultz@linaro.org> Link: https://lkml.kernel.org/r/20180427134016.2525989-4-arnd@arndb.de
2018-05-19timekeeping: Clean up ktime_get_real_ts64Arnd Bergmann
In a move to make ktime_get_*() the preferred driver interface into the timekeeping code, sanitizes ktime_get_real_ts64() to be a proper exported symbol rather than an alias for getnstimeofday64(). The internal __getnstimeofday64() is no longer used, so remove that and merge it into ktime_get_real_ts64(). Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: y2038@lists.linaro.org Cc: John Stultz <john.stultz@linaro.org> Link: https://lkml.kernel.org/r/20180427134016.2525989-3-arnd@arndb.de
2018-05-19timekeeping: Remove timespec64 hackArnd Bergmann
At this point, we have converted most of the kernel to use timespec64 consistently in place of timespec, so it seems it's time to make timespec64 the native structure and define timespec in terms of that one on 64-bit architectures. Starting with gcc-5, the compiler can completely optimize away the timespec_to_timespec64 and timespec64_to_timespec functions on 64-bit architectures. With older compilers, we introduce a couple of extra copies of local variables, but those are easily avoided by using the timespec64 based interfaces consistently, as we do in most of the important code paths already. The main upside of removing the hack is that printing the tv_sec field of a timespec64 structure can now use the %lld format string on all architectures without a cast to time64_t. Without this patch, the field is a 'long' type and would have to be printed using %ld on 64-bit architectures. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: y2038@lists.linaro.org Cc: John Stultz <john.stultz@linaro.org> Link: https://lkml.kernel.org/r/20180427134016.2525989-2-arnd@arndb.de
2018-05-19Merge branch 'linus' into timers/2038Thomas Gleixner
Merge upstream to pick up changes on which pending patches depend on.
2018-05-18bpf: allow sk_msg programs to read sock fieldsJohn Fastabend
Currently sk_msg programs only have access to the raw data. However, it is often useful when building policies to have the policies specific to the socket endpoint. This allows using the socket tuple as input into filters, etc. This patch adds ctx access to the sock fields. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-18audit: use existing session info functionRichard Guy Briggs
Use the existing audit_log_session_info() function rather than hardcoding its functionality. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-18workqueue: Show the latest workqueue name in /proc/PID/{comm,stat,status}Tejun Heo
There can be a lot of workqueue workers and they all show up with the cryptic kworker/* names making it difficult to understand which is doing what and how they came to be. # ps -ef | grep kworker root 4 2 0 Feb25 ? 00:00:00 [kworker/0:0H] root 6 2 0 Feb25 ? 00:00:00 [kworker/u112:0] root 19 2 0 Feb25 ? 00:00:00 [kworker/1:0H] root 25 2 0 Feb25 ? 00:00:00 [kworker/2:0H] root 31 2 0 Feb25 ? 00:00:00 [kworker/3:0H] ... This patch makes workqueue workers report the latest workqueue it was executing for through /proc/PID/{comm,stat,status}. The extra information is appended to the kthread name with intervening '+' if currently executing, otherwise '-'. # cat /proc/25/comm kworker/2:0-events_power_efficient # cat /proc/25/stat 25 (kworker/2:0-events_power_efficient) I 2 0 0 0 -1 69238880 0 0... # grep Name /proc/25/status Name: kworker/2:0-events_power_efficient Unfortunately, ps(1) truncates comm to 15 characters, # ps 25 PID TTY STAT TIME COMMAND 25 ? I 0:00 [kworker/2:0-eve] making it a lot less useful; however, this should be an easy fix from ps(1) side. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Craig Small <csmall@enc.com.au>
2018-05-18workqueue: Set worker->desc to workqueue name by defaultTejun Heo
Work functions can use set_worker_desc() to improve the visibility of what the worker task is doing. Currently, the desc field is unset at the beginning of each execution and there is a separate field to track the field is set during the current execution. Instead of leaving empty till desc is set, worker->desc can be used to remember the last workqueue the worker worked on by default and users that use set_worker_desc() can override it to something more informative as necessary. This simplifies desc handling and helps tracking the last workqueue that the worker exected on to improve visibility. Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-18workqueue: Make worker_attach/detach_pool() update worker->poolTejun Heo
For historical reasons, the worker attach/detach functions don't currently manage worker->pool and the callers are manually and inconsistently updating it. This patch moves worker->pool updates into the worker attach/detach functions. This makes worker->pool consistent and clearly defines how worker->pool updates are synchronized. This will help later workqueue visibility improvements by allowing safe access to workqueue information from worker->task. Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-18workqueue: Replace pool->attach_mutex with global wq_pool_attach_mutexTejun Heo
To improve workqueue visibility, we want to be able to access workqueue information from worker tasks. The per-pool attach mutex makes that difficult because there's no way of stabilizing task -> worker pool association without knowing the pool first. Worker attach/detach is a slow path and there's no need for different pools to be able to perform them concurrently. This patch replaces the per-pool attach_mutex with global wq_pool_attach_mutex to prepare for visibility improvement changes. Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-18scsi: zfcp: workqueue: set description for port work items with their WWPN ↵Steffen Maier
as context As a prerequisite, complement commit 3d1cb2059d93 ("workqueue: include workqueue info when printing debug dump of a worker task") to be usable with kernel modules by exporting the symbol set_worker_desc(). Current built-in user was introduced with commit ef3b101925f2 ("writeback: set worker desc to identify writeback workers in task dumps"). Can help distinguishing work items which do not have adapter scope. Description is printed out with task dump for debugging on WARN, BUG, panic, or magic-sysrq [show-task-states(t)]. Example: $ echo 0 >| /sys/bus/ccw/drivers/zfcp/0.0.1880/0x50050763031bd327/failed & $ echo 't' >| /proc/sysrq-trigger $ dmesg sysrq: SysRq : Show State task PC stack pid father ... zfcp_q_0.0.1880 S14640 2165 2 0x02000000 Call Trace: ([<00000000009df464>] __schedule+0xbf4/0xc78) [<00000000009df57c>] schedule+0x94/0xc0 [<0000000000168654>] rescuer_thread+0x33c/0x3a0 [<000000000016f8be>] kthread+0x166/0x178 [<00000000009e71f2>] kernel_thread_starter+0x6/0xc [<00000000009e71ec>] kernel_thread_starter+0x0/0xc no locks held by zfcp_q_0.0.1880/2165. ... kworker/u512:2 D11280 2193 2 0x02000000 Workqueue: zfcp_q_0.0.1880 zfcp_scsi_rport_work [zfcp] (zrpd-50050763031bd327) ^^^^^^^^^^^^^^^^^^^^^ Call Trace: ([<00000000009df464>] __schedule+0xbf4/0xc78) [<00000000009df57c>] schedule+0x94/0xc0 [<00000000009e50c0>] schedule_timeout+0x488/0x4d0 [<00000000001e425c>] msleep+0x5c/0x78 >>test code only<< [<000003ff8008a21e>] zfcp_scsi_rport_work+0xbe/0x100 [zfcp] [<0000000000167154>] process_one_work+0x3b4/0x718 [<000000000016771c>] worker_thread+0x264/0x408 [<000000000016f8be>] kthread+0x166/0x178 [<00000000009e71f2>] kernel_thread_starter+0x6/0xc [<00000000009e71ec>] kernel_thread_starter+0x0/0xc 2 locks held by kworker/u512:2/2193: #0: (name){++++.+}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718 #1: ((&(&port->rport_work)->work)){+.+.+.}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718 ... ============================================= Showing busy workqueues and worker pools: workqueue zfcp_q_0.0.1880: flags=0x2000a pwq 512: cpus=0-255 flags=0x4 nice=0 active=1/1 in-flight: 2193:zfcp_scsi_rport_work [zfcp] pool 512: cpus=0-255 flags=0x4 nice=0 hung=0s workers=4 idle: 5 2354 2311 Work items with adapter scope are already identified by the workqueue name "zfcp_q_<devbusid>" and the work item function name. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18xsk: clean up SPDX headersBjörn Töpel
Clean up SPDX-License-Identifier and removing licensing leftovers. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-18fsnotify: add fsnotify_add_inode_mark() wrappersAmir Goldstein
Before changing the arguments of the functions fsnotify_add_mark() and fsnotify_add_mark_locked(), convert most callers to use a wrapper. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18fsnotify: remove redundant arguments to handle_event()Amir Goldstein
inode_mark and vfsmount_mark arguments are passed to handle_event() operation as function arguments as well as on iter_info struct. The difference is that iter_info struct may contain marks that should not be handled and are represented as NULL arguments to inode_mark or vfsmount_mark. Instead of passing the inode_mark and vfsmount_mark arguments, add a report_mask member to iter_info struct to indicate which marks should be handled, versus marks that should only be kept alive during user wait. This change is going to be used for passing more mark types with handle_event() (i.e. super block marks). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18sched/deadline: Make the grub_reclaim() function staticMathieu Malaterre
Since the grub_reclaim() function can be made static, make it so. Silences the following GCC warning (W=1): kernel/sched/deadline.c:1120:5: warning: no previous prototype for ‘grub_reclaim’ [-Wmissing-prototypes] Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180516200902.959-1-malat@debian.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-18sched/debug: Move the print_rt_rq() and print_dl_rq() declarations to ↵Mathieu Malaterre
kernel/sched/sched.h In the following commit: 6b55c9654fcc ("sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h") the print_cfs_rq() prototype was added to <kernel/sched/sched.h>, right next to the prototypes for print_cfs_stats(), print_rt_stats() and print_dl_stats(). Finish this previous commit and also move related prototypes for print_rt_rq() and print_dl_rq(). Remove existing extern declarations now that they not needed anymore. Silences the following GCC warning, triggered by W=1: kernel/sched/debug.c:573:6: warning: no previous prototype for ‘print_rt_rq’ [-Wmissing-prototypes] kernel/sched/debug.c:603:6: warning: no previous prototype for ‘print_dl_rq’ [-Wmissing-prototypes] Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180516195348.30426-1-malat@debian.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-17bpf: fix truncated jump targets on heavy expansionsDaniel Borkmann
Recently during testing, I ran into the following panic: [ 207.892422] Internal error: Accessing user space memory outside uaccess.h routines: 96000004 [#1] SMP [ 207.901637] Modules linked in: binfmt_misc [...] [ 207.966530] CPU: 45 PID: 2256 Comm: test_verifier Tainted: G W 4.17.0-rc3+ #7 [ 207.974956] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB18A 03/31/2017 [ 207.982428] pstate: 60400005 (nZCv daif +PAN -UAO) [ 207.987214] pc : bpf_skb_load_helper_8_no_cache+0x34/0xc0 [ 207.992603] lr : 0xffff000000bdb754 [ 207.996080] sp : ffff000013703ca0 [ 207.999384] x29: ffff000013703ca0 x28: 0000000000000001 [ 208.004688] x27: 0000000000000001 x26: 0000000000000000 [ 208.009992] x25: ffff000013703ce0 x24: ffff800fb4afcb00 [ 208.015295] x23: ffff00007d2f5038 x22: ffff00007d2f5000 [ 208.020599] x21: fffffffffeff2a6f x20: 000000000000000a [ 208.025903] x19: ffff000009578000 x18: 0000000000000a03 [ 208.031206] x17: 0000000000000000 x16: 0000000000000000 [ 208.036510] x15: 0000ffff9de83000 x14: 0000000000000000 [ 208.041813] x13: 0000000000000000 x12: 0000000000000000 [ 208.047116] x11: 0000000000000001 x10: ffff0000089e7f18 [ 208.052419] x9 : fffffffffeff2a6f x8 : 0000000000000000 [ 208.057723] x7 : 000000000000000a x6 : 00280c6160000000 [ 208.063026] x5 : 0000000000000018 x4 : 0000000000007db6 [ 208.068329] x3 : 000000000008647a x2 : 19868179b1484500 [ 208.073632] x1 : 0000000000000000 x0 : ffff000009578c08 [ 208.078938] Process test_verifier (pid: 2256, stack limit = 0x0000000049ca7974) [ 208.086235] Call trace: [ 208.088672] bpf_skb_load_helper_8_no_cache+0x34/0xc0 [ 208.093713] 0xffff000000bdb754 [ 208.096845] bpf_test_run+0x78/0xf8 [ 208.100324] bpf_prog_test_run_skb+0x148/0x230 [ 208.104758] sys_bpf+0x314/0x1198 [ 208.108064] el0_svc_naked+0x30/0x34 [ 208.111632] Code: 91302260 f9400001 f9001fa1 d2800001 (29500680) [ 208.117717] ---[ end trace 263cb8a59b5bf29f ]--- The program itself which caused this had a long jump over the whole instruction sequence where all of the inner instructions required heavy expansions into multiple BPF instructions. Additionally, I also had BPF hardening enabled which requires once more rewrites of all constant values in order to blind them. Each time we rewrite insns, bpf_adj_branches() would need to potentially adjust branch targets which cross the patchlet boundary to accommodate for the additional delta. Eventually that lead to the case where the target offset could not fit into insn->off's upper 0x7fff limit anymore where then offset wraps around becoming negative (in s16 universe), or vice versa depending on the jump direction. Therefore it becomes necessary to detect and reject any such occasions in a generic way for native eBPF and cBPF to eBPF migrations. For the latter we can simply check bounds in the bpf_convert_filter()'s BPF_EMIT_JMP helper macro and bail out once we surpass limits. The bpf_patch_insn_single() for native eBPF (and cBPF to eBPF in case of subsequent hardening) is a bit more complex in that we need to detect such truncations before hitting the bpf_prog_realloc(). Thus the latter is split into an extra pass to probe problematic offsets on the original program in order to fail early. With that in place and carefully tested I no longer hit the panic and the rewrites are rejected properly. The above example panic I've seen on bpf-next, though the issue itself is generic in that a guard against this issue in bpf seems more appropriate in this case. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-18bpf: parse and verdict prog attach may race with bpf map updateJohn Fastabend
In the sockmap design BPF programs (SK_SKB_STREAM_PARSER, SK_SKB_STREAM_VERDICT and SK_MSG_VERDICT) are attached to the sockmap map type and when a sock is added to the map the programs are used by the socket. However, sockmap updates from both userspace and BPF programs can happen concurrently with the attach and detach of these programs. To resolve this we use the bpf_prog_inc_not_zero and a READ_ONCE() primitive to ensure the program pointer is not refeched and possibly NULL'd before the refcnt increment. This happens inside a RCU critical section so although the pointer reference in the map object may be NULL (by a concurrent detach operation) the reference from READ_ONCE will not be free'd until after grace period. This ensures the object returned by READ_ONCE() is valid through the RCU criticl section and safe to use as long as we "know" it may be free'd shortly. Daniel spotted a case in the sock update API where instead of using the READ_ONCE() program reference we used the pointer from the original map, stab->bpf_{verdict|parse|txmsg}. The problem with this is the logic checks the object returned from the READ_ONCE() is not NULL and then tries to reference the object again but using the above map pointer, which may have already been NULL'd by a parallel detach operation. If this happened bpf_porg_inc_not_zero could dereference a NULL pointer. Fix this by using variable returned by READ_ONCE() that is checked for NULL. Fixes: 2f857d04601a ("bpf: sockmap, remove STRPARSER map_flags and add multi-map support") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-18bpf: sockmap update rollback on error can incorrectly dec prog refcntJohn Fastabend
If the user were to only attach one of the parse or verdict programs then it is possible a subsequent sockmap update could incorrectly decrement the refcnt on the program. This happens because in the rollback logic, after an error, we have to decrement the program reference count when its been incremented. However, we only increment the program reference count if the user has both a verdict and a parse program. The reason for this is because, at least at the moment, both are required for any one to be meaningful. The problem fixed here is in the rollback path we decrement the program refcnt even if only one existing. But we never incremented the refcnt in the first place creating an imbalance. This patch fixes the error path to handle this case. Fixes: 2f857d04601a ("bpf: sockmap, remove STRPARSER map_flags and add multi-map support") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17bpf: sockmap, fix double-freeGustavo A. R. Silva
`e' is being freed twice. Fix this by removing one of the kfree() calls. Addresses-Coverity-ID: 1468983 ("Double free") Fixes: 81110384441a ("bpf: sockmap, add hash map support") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17bpf: sockmap, fix uninitialized variableGustavo A. R. Silva
There is a potential execution path in which variable err is returned without being properly initialized previously. Fix this by initializing variable err to 0. Addresses-Coverity-ID: 1468964 ("Uninitialized scalar variable") Fixes: e5cd3abcb31a ("bpf: sockmap, refactor sockmap routines to work with hashmap") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17audit: normalize loginuid read accessRichard Guy Briggs
Recognizing that the loginuid is an internal audit value, use an access function to retrieve the audit loginuid value for the task rather than reaching directly into the task struct to get it. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-17audit: use new audit_context access funciton for seccomp_actions_loggedRichard Guy Briggs
On the rebase of the following commit on the new seccomp actions_logged function, one audit_context access was missed. commit cdfb6b341f0f2409aba24b84f3b4b2bba50be5c5 ("audit: use inline function to get audit context") Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-05-17 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Provide a new BPF helper for doing a FIB and neighbor lookup in the kernel tables from an XDP or tc BPF program. The helper provides a fast-path for forwarding packets. The API supports IPv4, IPv6 and MPLS protocols, but currently IPv4 and IPv6 are implemented in this initial work, from David (Ahern). 2) Just a tiny diff but huge feature enabled for nfp driver by extending the BPF offload beyond a pure host processing offload. Offloaded XDP programs are allowed to set the RX queue index and thus opening the door for defining a fully programmable RSS/n-tuple filter replacement. Once BPF decided on a queue already, the device data-path will skip the conventional RSS processing completely, from Jakub. 3) The original sockmap implementation was array based similar to devmap. However unlike devmap where an ifindex has a 1:1 mapping into the map there are use cases with sockets that need to be referenced using longer keys. Hence, sockhash map is added reusing as much of the sockmap code as possible, from John. 4) Introduce BTF ID. The ID is allocatd through an IDR similar as with BPF maps and progs. It also makes BTF accessible to user space via BPF_BTF_GET_FD_BY_ID and adds exposure of the BTF data through BPF_OBJ_GET_INFO_BY_FD, from Martin. 5) Enable BPF stackmap with build_id also in NMI context. Due to the up_read() of current->mm->mmap_sem build_id cannot be parsed. This work defers the up_read() via a per-cpu irq_work so that at least limited support can be enabled, from Song. 6) Various BPF JIT follow-up cleanups and fixups after the LD_ABS/LD_IND JIT conversion as well as implementation of an optimized 32/64 bit immediate load in the arm64 JIT that allows to reduce the number of emitted instructions; in case of tested real-world programs they were shrinking by three percent, from Daniel. 7) Add ifindex parameter to the libbpf loader in order to enable BPF offload support. Right now only iproute2 can load offloaded BPF and this will also enable libbpf for direct integration into other applications, from David (Beckett). 8) Convert the plain text documentation under Documentation/bpf/ into RST format since this is the appropriate standard the kernel is moving to for all documentation. Also add an overview README.rst, from Jesper. 9) Add __printf verification attribute to the bpf_verifier_vlog() helper. Though it uses va_list we can still allow gcc to check the format string, from Mathieu. 10) Fix a bash reference in the BPF selftest's Makefile. The '|& ...' is a bash 4.0+ feature which is not guaranteed to be available when calling out to shell, therefore use a more portable variant, from Joe. 11) Fix a 64 bit division in xdp_umem_reg() by using div_u64() instead of relying on the gcc built-in, from Björn. 12) Fix a sock hashmap kmalloc warning reported by syzbot when an overly large key size is used in hashmap then causing overflows in htab->elem_size. Reject bogus attr->key_size early in the sock_hash_alloc(), from Yonghong. 13) Ensure in BPF selftests when urandom_read is being linked that --build-id is always enabled so that test_stacktrace_build_id[_nmi] won't be failing, from Alexei. 14) Add bitsperlong.h as well as errno.h uapi headers into the tools header infrastructure which point to one of the arch specific uapi headers. This was needed in order to fix a build error on some systems for the BPF selftests, from Sirio. 15) Allow for short options to be used in the xdp_monitor BPF sample code. And also a bpf.h tools uapi header sync in order to fix a selftest build failure. Both from Prashant. 16) More formally clarify the meaning of ID in the direct packet access section of the BPF documentation, from Wang. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-17bpf: sockmap, on update propagate errors back to userspaceJohn Fastabend
When an error happens in the update sockmap element logic also pass the err up to the user. Fixes: e5cd3abcb31a ("bpf: sockmap, refactor sockmap routines to work with hashmap") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17bpf: fix sock hashmap kmalloc warningYonghong Song
syzbot reported a kernel warning below: WARNING: CPU: 0 PID: 4499 at mm/slab_common.c:996 kmalloc_slab+0x56/0x70 mm/slab_common.c:996 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 4499 Comm: syz-executor050 Not tainted 4.17.0-rc3+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 panic+0x22f/0x4de kernel/panic.c:184 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 RIP: 0010:kmalloc_slab+0x56/0x70 mm/slab_common.c:996 RSP: 0018:ffff8801d907fc58 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8801aeecb280 RCX: ffffffff8185ebd7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffe1 RBP: ffff8801d907fc58 R08: ffff8801adb5e1c0 R09: ffffed0035a84700 R10: ffffed0035a84700 R11: ffff8801ad423803 R12: ffff8801aeecb280 R13: 00000000fffffff4 R14: ffff8801ad891a00 R15: 00000000014200c0 __do_kmalloc mm/slab.c:3713 [inline] __kmalloc+0x25/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:517 [inline] map_get_next_key+0x24a/0x640 kernel/bpf/syscall.c:858 __do_sys_bpf kernel/bpf/syscall.c:2131 [inline] __se_sys_bpf kernel/bpf/syscall.c:2096 [inline] __x64_sys_bpf+0x354/0x4f0 kernel/bpf/syscall.c:2096 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The test case is against sock hashmap with a key size 0xffffffe1. Such a large key size will cause the below code in function sock_hash_alloc() overflowing and produces a smaller elem_size, hence map creation will be successful. htab->elem_size = sizeof(struct htab_elem) + round_up(htab->map.key_size, 8); Later, when map_get_next_key is called and kernel tries to allocate the key unsuccessfully, it will issue the above warning. Similar to hashtab, ensure the key size is at most MAX_BPF_STACK for a successful map creation. Fixes: 81110384441a ("bpf: sockmap, add hash map support") Reported-by: syzbot+e4566d29080e7f3460ff@syzkaller.appspotmail.com Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-16clocksource: Move inline keyword to the beginning of function declarationsMathieu Malaterre
The inline keyword was not at the beginning of the function declarations. Fix the following warnings triggered when using W=1: kernel/time/clocksource.c:456:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] kernel/time/clocksource.c:457:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Link: https://lkml.kernel.org/r/20180516195943.31924-1-malat@debian.org
2018-05-16printk: fix possible reuse of va_list variableTetsuo Handa
I noticed that there is a possibility that printk_safe_log_store() causes kernel oops because "args" parameter is passed to vsnprintf() again when atomic_cmpxchg() detected that we raced. Fix this by using va_copy(). Link: http://lkml.kernel.org/r/201805112002.GIF21216.OFVHFOMLJtQFSO@I-love.SAKURA.ne.jp Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: dvyukov@google.com Cc: syzkaller@googlegroups.com Cc: fengguang.wu@intel.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: 42a0bb3f71383b45 ("printk/nmi: generic solution for safe printk in NMI") Cc: 4.7+ <stable@vger.kernel.org> # v4.7+ Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-05-16locking/percpu-rwsem: Annotate rwsem ownership transfer by setting ↵Waiman Long
RWSEM_OWNER_UNKNOWN The filesystem freezing code needs to transfer ownership of a rwsem embedded in a percpu-rwsem from the task that does the freezing to another one that does the thawing by calling percpu_rwsem_release() after freezing and percpu_rwsem_acquire() before thawing. However, the new rwsem debug code runs afoul with this scheme by warning that the task that releases the rwsem isn't the one that acquires it, as reported by Amir Goldstein: DEBUG_LOCKS_WARN_ON(sem->owner != get_current()) WARNING: CPU: 1 PID: 1401 at /home/amir/build/src/linux/kernel/locking/rwsem.c:133 up_write+0x59/0x79 Call Trace: percpu_up_write+0x1f/0x28 thaw_super_locked+0xdf/0x120 do_vfs_ioctl+0x270/0x5f1 ksys_ioctl+0x52/0x71 __x64_sys_ioctl+0x16/0x19 do_syscall_64+0x5d/0x167 entry_SYSCALL_64_after_hwframe+0x49/0xbe To work properly with the rwsem debug code, we need to annotate that the rwsem ownership is unknown during the tranfer period until a brave soul comes forward to acquire the ownership. During that period, optimistic spinning will be disabled. Reported-by: Amir Goldstein <amir73il@gmail.com> Tested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Theodore Y. Ts'o <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-fsdevel@vger.kernel.org Link: http://lkml.kernel.org/r/1526420991-21213-3-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-16locking/rwsem: Add a new RWSEM_ANONYMOUSLY_OWNED flagWaiman Long
There are use cases where a rwsem can be acquired by one task, but released by another task. In thess cases, optimistic spinning may need to be disabled. One example will be the filesystem freeze/thaw code where the task that freezes the filesystem will acquire a write lock on a rwsem and then un-owns it before returning to userspace. Later on, another task will come along, acquire the ownership, thaw the filesystem and release the rwsem. Bit 0 of the owner field was used to designate that it is a reader owned rwsem. It is now repurposed to mean that the owner of the rwsem is not known. If only bit 0 is set, the rwsem is reader owned. If bit 0 and other bits are set, it is writer owned with an unknown owner. One such value for the latter case is (-1L). So we can set owner to 1 for reader-owned, -1 for writer-owned. The owner is unknown in both cases. To handle transfer of rwsem ownership, the higher level code should set the owner field to -1 to indicate a write-locked rwsem with unknown owner. Optimistic spinning will be disabled in this case. Once the higher level code figures who the new owner is, it can then set the owner field accordingly. Tested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Theodore Y. Ts'o <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-fsdevel@vger.kernel.org Link: http://lkml.kernel.org/r/1526420991-21213-2-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-16Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu - Updates to the handling of expedited grace periods, perhaps most notably parallelizing their initialization. Other changes include fixes from Boqun Feng. - Miscellaneous fixes. These include an nvme fix from Nitzan Carmi that I am carrying because it depends on a new SRCU function cleanup_srcu_struct_quiesced(). This branch also includes fixes from Byungchul Park and Yury Norov. - Updates to reduce lock contention in the rcu_node combining tree. These are in preparation for the consolidation of RCU-bh, RCU-preempt, and RCU-sched into a single flavor, which was requested by Linus Torvalds in response to a security flaw whose root cause included confusion between the multiple flavors of RCU. - Torture-test updates that save their users some time and effort. Conflicts: drivers/nvme/host/core.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15memremap: split devm_memremap_pages() and memremap() infrastructureDan Williams
Currently, kernel/memremap.c contains generic code for supporting memremap() (CONFIG_HAS_IOMEM) and devm_memremap_pages() (CONFIG_ZONE_DEVICE). This causes ongoing build maintenance problems as additions to memremap.c, especially for the ZONE_DEVICE case, need to be careful about being placed in ifdef guards. Remove the need for these ifdef guards by moving the ZONE_DEVICE support functions to their own compilation unit. Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-16resource: switch to proc_create_seq_dataChristoph Hellwig
And use the root resource directly from the proc private data. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16proc: introduce proc_create_single{,_data}Christoph Hellwig
Variants of proc_create{,_data} that directly take a seq_file show callback and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16proc: introduce proc_create_seq_privateChristoph Hellwig
Variant of proc_create_data that directly take a struct seq_operations argument + a private state size and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16proc: introduce proc_create_seq{,_data}Christoph Hellwig
Variants of proc_create{,_data} that directly take a struct seq_operations argument and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-15tick/broadcast: Use for_each_cpu() specially on UP kernelsDexuan Cui
for_each_cpu() unintuitively reports CPU0 as set independent of the actual cpumask content on UP kernels. This causes an unexpected PIT interrupt storm on a UP kernel running in an SMP virtual machine on Hyper-V, and as a result, the virtual machine can suffer from a strange random delay of 1~20 minutes during boot-up, and sometimes it can hang forever. Protect if by checking whether the cpumask is empty before entering the for_each_cpu() loop. [ tglx: Use !IS_ENABLED(CONFIG_SMP) instead of #ifdeffery ] Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poulson <jopoulso@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: stable@vger.kernel.org Cc: Rakib Mullick <rakib.mullick@gmail.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KY Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Link: https://lkml.kernel.org/r/KL1P15301MB000678289FE55BA365B3279ABF990@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM Link: https://lkml.kernel.org/r/KL1P15301MB0006FA63BC22BEB64902EAA0BF930@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
2018-05-15bpf: sockmap, add hash map supportJohn Fastabend
Sockmap is currently backed by an array and enforces keys to be four bytes. This works well for many use cases and was originally modeled after devmap which also uses four bytes keys. However, this has become limiting in larger use cases where a hash would be more appropriate. For example users may want to use the 5-tuple of the socket as the lookup key. To support this add hash support. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-15Merge branches 'exp.2018.05.15a', 'fixes.2018.05.15a', 'lock.2018.05.15a' ↵Paul E. McKenney
and 'torture.2018.05.15a' into HEAD exp.2018.05.15a: Parallelize expedited grace-period initialization. fixes.2018.05.15a: Miscellaneous fixes. lock.2018.05.15a: Decrease lock contention on root rcu_node structure, which is a step towards merging RCU flavors. torture.2018.05.15a: Torture-test updates.
2018-05-15rcutorture: Print end-of-test statePaul E. McKenney
This commit adds end-of-test state printout to help check whether RCU shut down nicely. Note that this printout only helps for flavors of RCU that are not used much by the kernel. In particular, for normal RCU having a grace period in progress is expected behavior. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Nicholas Piggin <npiggin@gmail.com>
2018-05-15rcu: Drop early GP request check from rcu_gp_kthread()Paul E. McKenney
Now that grace-period requests use funnel locking and now that they set ->gp_flags to RCU_GP_FLAG_INIT even when the RCU grace-period kthread has not yet started, rcu_gp_kthread() no longer needs to check need_any_future_gp() at startup time. This commit therefore removes this check. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Nicholas Piggin <npiggin@gmail.com>
2018-05-15rcu: Simplify and inline cpu_needs_another_gp()Paul E. McKenney
Now that RCU no longer relies on failsafe checks, cpu_needs_another_gp() can be greatly simplified. This simplification eliminates the last call to rcu_future_needs_gp() and to rcu_segcblist_future_gp_needed(), both of which which can then be eliminated. And then, because cpu_needs_another_gp() is called only from __rcu_pending(), it can be inlined and eliminated. This commit carries out the simplification, inlining, and elimination called out above. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Nicholas Piggin <npiggin@gmail.com>
2018-05-15rcu: The rcu_gp_cleanup() function does not need cpu_needs_another_gp()Paul E. McKenney
All of the cpu_needs_another_gp() function's checks (except for newly arrived callbacks) have been subsumed into the rcu_gp_cleanup() function's scan of the rcu_node tree. This commit therefore drops the call to cpu_needs_another_gp(). The check for newly arrived callbacks is supplied by rcu_accelerate_cbs(). Any needed advancing (as in the earlier rcu_advance_cbs() call) will be supplied when the corresponding CPU becomes aware of the end of the now-completed grace period. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Nicholas Piggin <npiggin@gmail.com>
2018-05-15rcu: Make rcu_start_this_gp() check for out-of-range requestsPaul E. McKenney
If rcu_start_this_gp() is invoked with a requested grace period more than three in the future, then either the ->need_future_gp[] array needs to be bigger or the caller needs to be repaired. This commit therefore adds a WARN_ON_ONCE() checking for this condition. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Nicholas Piggin <npiggin@gmail.com>