Filling in the padding slot in the bpf structure as a bug fix in 'ne'
overlapped with actually using that padding area for something in
'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
bugs that deal with triggers and instances.
The first is a generic trigger bug where the triggers are not removed
from a link list properly when deleting an instance.
The second is specific to snapshots, where the snapshot is does the
snapshot to the top level buffer, when it is suppose to snapshot the
buffer associated to the instance the snapshot trigger exists in.
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Merge tag 'trace-v4.17-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"While writing selftests for a new feature, I triggered two existing
bugs that deal with triggers and instances.
- a generic trigger bug where the triggers are not removed from a
linked list properly when deleting an instance.
- a bug specific to snapshots, where the snapshot is done in the top
level buffer, when it is supposed to snapshot the buffer associated
to the instance the snapshot trigger exists in"
* tag 'trace-v4.17-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Make the snapshot trigger work with instances
tracing: Fix crash when freeing instances with event triggers
The snapshot trigger currently only affects the main ring buffer, even when
it is used by the instances. This can be confusing as the snapshot trigger
is listed in the instance.
> # cd /sys/kernel/tracing
> # mkdir instances/foo
> # echo snapshot > instances/foo/events/syscalls/sys_enter_fchownat/trigger
> # echo top buffer > trace_marker
> # echo foo buffer > instances/foo/trace_marker
> # touch /tmp/bar
> # chown rostedt /tmp/bar
> # cat instances/foo/snapshot
# tracer: nop
#
#
# * Snapshot is freed *
#
# Snapshot commands:
# echo 0 > snapshot : Clears and frees snapshot buffer
# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
# Takes a snapshot of the main buffer.
# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)
# (Doesn't have to be '2' works with any number that
# is not a '0' or '1')
> # cat snapshot
# tracer: nop
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
bash-1189 [000] .... 111.488323: tracing_mark_write: top buffer
Not only did the snapshot occur in the top level buffer, but the instance
snapshot buffer should have been allocated, and it is still free.
Cc: stable@vger.kernel.org
Fixes: 85f2b08268 ("tracing: Add basic event trigger framework")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If a instance has an event trigger enabled when it is freed, it could cause
an access of free memory. Here's the case that crashes:
# cd /sys/kernel/tracing
# mkdir instances/foo
# echo snapshot > instances/foo/events/initcall/initcall_start/trigger
# rmdir instances/foo
Would produce:
general protection fault: 0000 [#1] PREEMPT SMP PTI
Modules linked in: tun bridge ...
CPU: 5 PID: 6203 Comm: rmdir Tainted: G W 4.17.0-rc4-test+ #933
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
RIP: 0010:clear_event_triggers+0x3b/0x70
RSP: 0018:ffffc90003783de0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 6b6b6b6b6b6b6b2b RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800c7130ba0
RBP: ffffc90003783e00 R08: ffff8801131993f8 R09: 0000000100230016
R10: ffffc90003783d80 R11: 0000000000000000 R12: ffff8800c7130ba0
R13: ffff8800c7130bd8 R14: ffff8800cc093768 R15: 00000000ffffff9c
FS: 00007f6f4aa86700(0000) GS:ffff88011eb40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f4a5aed60 CR3: 00000000cd552001 CR4: 00000000001606e0
Call Trace:
event_trace_del_tracer+0x2a/0xc5
instance_rmdir+0x15c/0x200
tracefs_syscall_rmdir+0x52/0x90
vfs_rmdir+0xdb/0x160
do_rmdir+0x16d/0x1c0
__x64_sys_rmdir+0x17/0x20
do_syscall_64+0x55/0x1a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
This was due to the call the clears out the triggers when an instance is
being deleted not removing the trigger from the link list.
Cc: stable@vger.kernel.org
Fixes: 85f2b08268 ("tracing: Add basic event trigger framework")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull scheduler fixes from Thomas Gleixner:
"Three fixes for scheduler and kthread code:
- allow calling kthread_park() on an already parked thread
- restore the sched_pi_setprio() tracepoint behaviour
- clarify the unclear string for the scheduling domain debug output"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched, tracing: Fix trace_sched_pi_setprio() for deboosting
kthread: Allow kthread_park() on a parked kthread
sched/topology: Clarify root domain(s) debug string
Merge misc fixes from Andrew Morton:
"16 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
kasan: fix memory hotplug during boot
kasan: free allocated shadow memory on MEM_CANCEL_ONLINE
checkpatch: fix macro argument precedence test
init/main.c: include <linux/mem_encrypt.h>
kernel/sys.c: fix potential Spectre v1 issue
mm/memory_hotplug: fix leftover use of struct page during hotplug
proc: fix smaps and meminfo alignment
mm: do not warn on offline nodes unless the specific node is explicitly requested
mm, memory_hotplug: make has_unmovable_pages more robust
mm/kasan: don't vfree() nonexistent vm_area
MAINTAINERS: change hugetlbfs maintainer and update files
ipc/shm: fix shmat() nil address after round-down when remapping
Revert "ipc/shm: Fix shmat mmap nil-page protection"
idr: fix invalid ptr dereference on item delete
ocfs2: revert "ocfs2/o2hb: check len for bio_add_page() to avoid getting incorrect bio"
mm: fix nr_rotate_swap leak in swapon() error case
Pull networking fixes from David Miller:
"Let's begin the holiday weekend with some networking fixes:
1) Whoops need to restrict cfg80211 wiphy names even more to 64
bytes. From Eric Biggers.
2) Fix flags being ignored when using kernel_connect() with SCTP,
from Xin Long.
3) Use after free in DCCP, from Alexey Kodanev.
4) Need to check rhltable_init() return value in ipmr code, from Eric
Dumazet.
5) XDP handling fixes in virtio_net from Jason Wang.
6) Missing RTA_TABLE in rtm_ipv4_policy[], from Roopa Prabhu.
7) Need to use IRQ disabling spinlocks in mlx4_qp_lookup(), from Jack
Morgenstein.
8) Prevent out-of-bounds speculation using indexes in BPF, from
Daniel Borkmann.
9) Fix regression added by AF_PACKET link layer cure, from Willem de
Bruijn.
10) Correct ENIC dma mask, from Govindarajulu Varadarajan.
11) Missing config options for PMTU tests, from Stefano Brivio"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (48 commits)
ibmvnic: Fix partial success login retries
selftests/net: Add missing config options for PMTU tests
mlx4_core: allocate ICM memory in page size chunks
enic: set DMA mask to 47 bit
ppp: remove the PPPIOCDETACH ioctl
ipv4: remove warning in ip_recv_error
net : sched: cls_api: deal with egdev path only if needed
vhost: synchronize IOTLB message with dev cleanup
packet: fix reserve calculation
net/mlx5: IPSec, Fix a race between concurrent sandbox QP commands
net/mlx5e: When RXFCS is set, add FCS data into checksum calculation
bpf: properly enforce index mask to prevent out-of-bounds speculation
net/mlx4: Fix irq-unsafe spinlock usage
net: phy: broadcom: Fix bcm_write_exp()
net: phy: broadcom: Fix auxiliary control register reads
net: ipv4: add missing RTA_TABLE to rtm_ipv4_policy
net/mlx4: fix spelling mistake: "Inrerface" -> "Interface" and rephrase message
ibmvnic: Only do H_EOI for mobility events
tuntap: correctly set SOCKWQ_ASYNC_NOSPACE
virtio-net: fix leaking page for gso packet during mergeable XDP
...
`resource' can be controlled by user-space, hence leading to a potential
exploitation of the Spectre variant 1 vulnerability.
This issue was detected with the help of Smatch:
kernel/sys.c:1474 __do_compat_sys_old_getrlimit() warn: potential spectre issue 'get_current()->signal->rlim' (local cap)
kernel/sys.c:1455 __do_sys_old_getrlimit() warn: potential spectre issue 'get_current()->signal->rlim' (local cap)
Fix this by sanitizing *resource* before using it to index
current->signal->rlim
Notice that given that speculation windows are large, the policy is to
kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].
[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
Link: http://lkml.kernel.org/r/20180515030038.GA11822@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Borkmann says:
====================
pull-request: bpf 2018-05-24
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix a bug in the original fix to prevent out of bounds speculation when
multiple tail call maps from different branches or calls end up at the
same tail call helper invocation, from Daniel.
2) Two selftest fixes, one in reuseport_bpf_numa where test is skipped in
case of missing numa support and another one to update kernel config to
properly support xdp_meta.sh test, from Anders.
...
Would be great if you have a chance to merge net into net-next after that.
The verifier fix would be needed later as a dependency in bpf-next for
upcomig work there. When you do the merge there's a trivial conflict on
BPF side with 849fa50662 ("bpf/verifier: refine retval R0 state for
bpf_get_stack helper"): Resolution is to keep both functions, the
do_refine_retval_range() and record_func_map().
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The following commit:
85f1abe001 ("kthread, sched/wait: Fix kthread_parkme() completion issue")
added a WARN() in the case where we call kthread_park() on an already
parked thread, because the old code wasn't doing the right thing there
and it wasn't at all clear that would happen.
It turns out, this does in fact happen, so we have to deal with it.
Instead of potentially returning early, also wait for the completion.
This does however mean we have to use complete_all() and re-initialize
the completion on re-use.
Reported-by: LKP <lkp@01.org>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel test robot <lkp@intel.com>
Cc: wfg@linux.intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 85f1abe001 ("kthread, sched/wait: Fix kthread_parkme() completion issue")
Link: http://lkml.kernel.org/r/20180504091142.GI12235@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2018-05-24
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc).
2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers.
3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit.
4) Jiong Wang adds support for indirect and arithmetic shifts to NFP
5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible.
6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing
to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions.
7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT.
8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events.
9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Extending tracepoint xdp:xdp_devmap_xmit in devmap with an err code
allow people to easier identify the reason behind the ndo_xdp_xmit
call to a given driver is failing.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch change the API for ndo_xdp_xmit to support bulking
xdp_frames.
When kernel is compiled with CONFIG_RETPOLINE, XDP sees a huge slowdown.
Most of the slowdown is caused by DMA API indirect function calls, but
also the net_device->ndo_xdp_xmit() call.
Benchmarked patch with CONFIG_RETPOLINE, using xdp_redirect_map with
single flow/core test (CPU E5-1650 v4 @ 3.60GHz), showed
performance improved:
for driver ixgbe: 6,042,682 pps -> 6,853,768 pps = +811,086 pps
for driver i40e : 6,187,169 pps -> 6,724,519 pps = +537,350 pps
With frames avail as a bulk inside the driver ndo_xdp_xmit call,
further optimizations are possible, like bulk DMA-mapping for TX.
Testing without CONFIG_RETPOLINE show the same performance for
physical NIC drivers.
The virtual NIC driver tun sees a huge performance boost, as it can
avoid doing per frame producer locking, but instead amortize the
locking cost over the bulk.
V2: Fix compile errors reported by kbuild test robot <lkp@intel.com>
V4: Isolated ndo, driver changes and callers.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When sending an xdp_frame through xdp_do_redirect call, then error
cases can happen where the xdp_frame needs to be dropped, and
returning an -errno code isn't sufficient/possible any-longer
(e.g. for cpumap case). This is already fully supported, by simply
calling xdp_return_frame.
This patch is an optimization, which provides xdp_return_frame_rx_napi,
which is a faster variant for these error cases. It take advantage of
the protection provided by XDP RX running under NAPI protection.
This change is mostly relevant for drivers using the page_pool
allocator as it can take advantage of this. (Tested with mlx5).
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Notice how this allow us get XDP statistic without affecting the XDP
performance, as tracepoint is no-longer activated on a per packet basis.
V5: Spotted by John Fastabend.
Fix 'sent' also counted 'drops' in this patch, a later patch corrected
this, but it was a mistake in this intermediate step.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Like cpumap create queue for xdp frames that will be bulked. For now,
this patch simply invoke ndo_xdp_xmit foreach frame. This happens,
either when the map flush operation is envoked, or when the limit
DEV_MAP_BULK_SIZE is reached.
V5: Avoid memleak on error path in dev_map_update_elem()
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Functionality is the same, but the ndo_xdp_xmit call is now
simply invoked from inside the devmap.c code.
V2: Fix compile issue reported by kbuild test robot <lkp@intel.com>
V5: Cleanups requested by Daniel
- Newlines before func definition
- Use BUILD_BUG_ON checks
- Remove unnecessary use return value store in dev_map_enqueue
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, suppose a userspace application has loaded a bpf program
and attached it to a tracepoint/kprobe/uprobe, and a bpf
introspection tool, e.g., bpftool, wants to show which bpf program
is attached to which tracepoint/kprobe/uprobe. Such attachment
information will be really useful to understand the overall bpf
deployment in the system.
There is a name field (16 bytes) for each program, which could
be used to encode the attachment point. There are some drawbacks
for this approaches. First, bpftool user (e.g., an admin) may not
really understand the association between the name and the
attachment point. Second, if one program is attached to multiple
places, encoding a proper name which can imply all these
attachments becomes difficult.
This patch introduces a new bpf subcommand BPF_TASK_FD_QUERY.
Given a pid and fd, if the <pid, fd> is associated with a
tracepoint/kprobe/uprobe perf event, BPF_TASK_FD_QUERY will return
. prog_id
. tracepoint name, or
. k[ret]probe funcname + offset or kernel addr, or
. u[ret]probe filename + offset
to the userspace.
The user can use "bpftool prog" to find more information about
bpf program itself with prog_id.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A new extern function, perf_get_event(), is added to return a perf event
given a struct file. This function will be used in later patches.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
While reviewing the verifier code, I recently noticed that the
following two program variants in relation to tail calls can be
loaded.
Variant 1:
# bpftool p d x i 15
0: (15) if r1 == 0x0 goto pc+3
1: (18) r2 = map[id:5]
3: (05) goto pc+2
4: (18) r2 = map[id:6]
6: (b7) r3 = 7
7: (35) if r3 >= 0xa0 goto pc+2
8: (54) (u32) r3 &= (u32) 255
9: (85) call bpf_tail_call#12
10: (b7) r0 = 1
11: (95) exit
# bpftool m s i 5
5: prog_array flags 0x0
key 4B value 4B max_entries 4 memlock 4096B
# bpftool m s i 6
6: prog_array flags 0x0
key 4B value 4B max_entries 160 memlock 4096B
Variant 2:
# bpftool p d x i 20
0: (15) if r1 == 0x0 goto pc+3
1: (18) r2 = map[id:8]
3: (05) goto pc+2
4: (18) r2 = map[id:7]
6: (b7) r3 = 7
7: (35) if r3 >= 0x4 goto pc+2
8: (54) (u32) r3 &= (u32) 3
9: (85) call bpf_tail_call#12
10: (b7) r0 = 1
11: (95) exit
# bpftool m s i 8
8: prog_array flags 0x0
key 4B value 4B max_entries 160 memlock 4096B
# bpftool m s i 7
7: prog_array flags 0x0
key 4B value 4B max_entries 4 memlock 4096B
In both cases the index masking inserted by the verifier in order
to control out of bounds speculation from a CPU via b2157399cc
("bpf: prevent out-of-bounds speculation") seems to be incorrect
in what it is enforcing. In the 1st variant, the mask is applied
from the map with the significantly larger number of entries where
we would allow to a certain degree out of bounds speculation for
the smaller map, and in the 2nd variant where the mask is applied
from the map with the smaller number of entries, we get buggy
behavior since we truncate the index of the larger map.
The original intent from commit b2157399cc is to reject such
occasions where two or more different tail call maps are used
in the same tail call helper invocation. However, the check on
the BPF_MAP_PTR_POISON is never hit since we never poisoned the
saved pointer in the first place! We do this explicitly for map
lookups but in case of tail calls we basically used the tail
call map in insn_aux_data that was processed in the most recent
path which the verifier walked. Thus any prior path that stored
a pointer in insn_aux_data at the helper location was always
overridden.
Fix it by moving the map pointer poison logic into a small helper
that covers both BPF helpers with the same logic. After that in
fixup_bpf_calls() the poison check is then hit for tail calls
and the program rejected. Latter only happens in unprivileged
case since this is the *only* occasion where a rewrite needs to
happen, and where such rewrite is specific to the map (max_entries,
index_mask). In the privileged case the rewrite is generic for
the insn->imm / insn->code update so multiple maps from different
paths can be handled just fine since all the remaining logic
happens in the instruction processing itself. This is similar
to the case of map lookups: in case there is a collision of
maps in fixup_bpf_calls() we must skip the inlined rewrite since
this will turn the generic instruction sequence into a non-
generic one. Thus the patch_call_imm will simply update the
insn->imm location where the bpf_map_lookup_elem() will later
take care of the dispatch. Given we need this 'poison' state
as a check, the information of whether a map is an unpriv_array
gets lost, so enforcing it prior to that needs an additional
state. In general this check is needed since there are some
complex and tail call intensive BPF programs out there where
LLVM tends to generate such code occasionally. We therefore
convert the map_ptr rather into map_state to store all this
w/o extra memory overhead, and the bit whether one of the maps
involved in the collision was from an unpriv_array thus needs
to be retained as well there.
Fixes: b2157399cc ("bpf: prevent out-of-bounds speculation")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.
Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.
Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.
This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.
The BPF program may return 3 types of return codes:
- BPF_OK: the End.BPF action will look up the next destination through
seg6_lookup_nexthop.
- BPF_REDIRECT: if an action has been executed through the
bpf_lwt_seg6_action helper, the BPF program should return this
value, as the skb's destination is already set and the default
lookup should not be performed.
- BPF_DROP : the packet will be dropped.
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This adds new two new fields to struct bpf_prog_info. For
multi-function programs, these fields can be used to pass
a list of the JITed image lengths of each function for a
given program to userspace using the bpf system call with
the BPF_OBJ_GET_INFO_BY_FD command.
This can be used by userspace applications like bpftool
to split up the contiguous JITed dump, also obtained via
the system call, into more relatable chunks corresponding
to each function.
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Currently, for multi-function programs, we cannot get the JITed
instructions using the bpf system call's BPF_OBJ_GET_INFO_BY_FD
command. Because of this, userspace tools such as bpftool fail
to identify a multi-function program as being JITed or not.
With the JIT enabled and the test program running, this can be
verified as follows:
# cat /proc/sys/net/core/bpf_jit_enable
1
Before applying this patch:
# bpftool prog list
1: kprobe name foo tag b811aab41a39ad3d gpl
loaded_at 2018-05-16T11:43:38+0530 uid 0
xlated 216B not jited memlock 65536B
...
# bpftool prog dump jited id 1
no instructions returned
After applying this patch:
# bpftool prog list
1: kprobe name foo tag b811aab41a39ad3d gpl
loaded_at 2018-05-16T12:13:01+0530 uid 0
xlated 216B jited 308B memlock 65536B
...
# bpftool prog dump jited id 1
0: nop
4: nop
8: mflr r0
c: std r0,16(r1)
10: stdu r1,-112(r1)
14: std r31,104(r1)
18: addi r31,r1,48
1c: li r3,10
...
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This adds new two new fields to struct bpf_prog_info. For
multi-function programs, these fields can be used to pass
a list of kernel symbol addresses for all functions in a
given program to userspace using the bpf system call with
the BPF_OBJ_GET_INFO_BY_FD command.
When bpf_jit_kallsyms is enabled, we can get the address
of the corresponding kernel symbol for a callee function
and resolve the symbol's name. The address is determined
by adding the value of the call instruction's imm field
to __bpf_call_base. This offset gets assigned to the imm
field by the verifier.
For some architectures, such as powerpc64, the imm field
is not large enough to hold this offset.
We resolve this by:
[1] Assigning the subprog id to the imm field of a call
instruction in the verifier instead of the offset of
the callee's symbol's address from __bpf_call_base.
[2] Determining the address of a callee's corresponding
symbol by using the imm field as an index for the
list of kernel symbol addresses now available from
the program info.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The imm field of a bpf instruction is a signed 32-bit integer.
For JITed bpf-to-bpf function calls, it holds the offset of the
start address of the callee's JITed image from __bpf_call_base.
For some architectures, such as powerpc64, this offset may be
as large as 64 bits and cannot be accomodated in the imm field
without truncation.
We resolve this by:
[1] Additionally using the auxiliary data of each function to
keep a list of start addresses of the JITed images for all
functions determined by the verifier.
[2] Retaining the subprog id inside the off field of the call
instructions and using it to index into the list mentioned
above and lookup the callee's address.
To make sure that the existing JIT compilers continue to work
without requiring changes, we keep the imm field as it is.
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Sparse warning:
kernel/bpf/btf.c:1985:34: warning: Variable length array is used.
This patch directly uses ARRAY_SIZE().
Fixes: f80442a4cd ("bpf: btf: Change how section is supported in btf_header")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Introduce helper:
int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
struct umh_info {
struct file *pipe_to_umh;
struct file *pipe_from_umh;
pid_t pid;
};
that GPLed kernel modules (signed or unsigned) can use it to execute part
of its own data as swappable user mode process.
The kernel will do:
- allocate a unique file in tmpfs
- populate that file with [data, data + len] bytes
- user-mode-helper code will do_execve that file and, before the process
starts, the kernel will create two unix pipes for bidirectional
communication between kernel module and umh
- close tmpfs file, effectively deleting it
- the fork_usermode_blob will return zero on success and populate
'struct umh_info' with two unix pipes and the pid of the user process
As the first step in the development of the bpfilter project
the fork_usermode_blob() helper is introduced to allow user mode code
to be invoked from a kernel module. The idea is that user mode code plus
normal kernel module code are built as part of the kernel build
and installed as traditional kernel module into distro specified location,
such that from a distribution point of view, there is
no difference between regular kernel modules and kernel modules + umh code.
Such modules can be signed, modprobed, rmmod, etc. The use of this new helper
by a kernel module doesn't make it any special from kernel and user space
tooling point of view.
Such approach enables kernel to delegate functionality traditionally done
by the kernel modules into the user space processes (either root or !root) and
reduces security attack surface of the new code. The buggy umh code would crash
the user process, but not the kernel. Another advantage is that umh code
of the kernel module can be debugged and tested out of user space
(e.g. opening the possibility to run clang sanitizers, fuzzers or
user space test suites on the umh code).
In case of the bpfilter project such architecture allows complex control plane
to be done in the user space while bpf based data plane stays in the kernel.
Since umh can crash, can be oom-ed by the kernel, killed by the admin,
the kernel module that uses them (like bpfilter) needs to manage life
time of umh on its own via two unix pipes and the pid of umh.
The exit code of such kernel module should kill the umh it started,
so that rmmod of the kernel module will cleanup the corresponding umh.
Just like if the kernel module does kmalloc() it should kfree() it
in the exit code.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In "struct bpf_map_info", the name "btf_id", "btf_key_id" and "btf_value_id"
could cause confusion because the "id" of "btf_id" means the BPF obj id
given to the BTF object while
"btf_key_id" and "btf_value_id" means the BTF type id within
that BTF object.
To make it clear, btf_key_id and btf_value_id are
renamed to btf_key_type_id and btf_value_type_id.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch does the followings:
1. Limit BTF_MAX_TYPES and BTF_MAX_NAME_OFFSET to 64k. We can
raise it later.
2. Remove the BTF_TYPE_PARENT and BTF_STR_TBL_ELF_ID. They are
currently encoded at the highest bit of a u32.
It is because the current use case does not require supporting
parent type (i.e type_id referring to a type in another BTF file).
It also does not support referring to a string in ELF.
The BTF_TYPE_PARENT and BTF_STR_TBL_ELF_ID checks are replaced
by BTF_TYPE_ID_CHECK and BTF_STR_OFFSET_CHECK which are
defined in btf.c instead of uapi/linux/btf.h.
3. Limit the BTF_INFO_KIND from 5 bits to 4 bits which is enough.
There is unused bits headroom if we ever needed it later.
4. The root bit in BTF_INFO is also removed because it is not
used in the current use case.
5. Remove BTF_INT_VARARGS since func type is not supported now.
The BTF_INT_ENCODING is limited to 4 bits instead of 8 bits.
The above can be added back later because the verifier
ensures the unused bits are zeros.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Instead of ingoring the array->index_type field. Enforce that
it must be a BTF_KIND_INT in size 1/2/4/8 bytes.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
There are currently unused section descriptions in the btf_header. Those
sections are here to support future BTF use cases. For example, the
func section (func_off) is to support function signature (e.g. the BPF
prog function signature).
Instead of spelling out all potential sections up-front in the btf_header.
This patch makes changes to btf_header such that extending it (e.g. adding
a section) is possible later. The unused ones can be removed for now and
they can be added back later.
This patch:
1. adds a hdr_len to the btf_header. It will allow adding
sections (and other info like parent_label and parent_name)
later. The check is similar to the existing bpf_attr.
If a user passes in a longer hdr_len, the kernel
ensures the extra tailing bytes are 0.
2. allows the section order in the BTF object to be
different from its sec_off order in btf_header.
3. each sec_off is followed by a sec_len. It must not have gap or
overlapping among sections.
The string section is ensured to be at the end due to the 4 bytes
alignment requirement of the type section.
The above changes will allow enough flexibility to
add new sections (and other info) to the btf_header later.
This patch also removes an unnecessary !err check
at the end of btf_parse().
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch exposes check_uarg_tail_zero() which will
be reused by a later BTF patch. Its name is changed to
bpf_check_uarg_tail_zero().
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge speculative store buffer bypass fixes from Thomas Gleixner:
- rework of the SPEC_CTRL MSR management to accomodate the new fancy
SSBD (Speculative Store Bypass Disable) bit handling.
- the CPU bug and sysfs infrastructure for the exciting new Speculative
Store Bypass 'feature'.
- support for disabling SSB via LS_CFG MSR on AMD CPUs including
Hyperthread synchronization on ZEN.
- PRCTL support for dynamic runtime control of SSB
- SECCOMP integration to automatically disable SSB for sandboxed
processes with a filter flag for opt-out.
- KVM integration to allow guests fiddling with SSBD including the new
software MSR VIRT_SPEC_CTRL to handle the LS_CFG based oddities on
AMD.
- BPF protection against SSB
.. this is just the core and x86 side, other architecture support will
come separately.
* 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
bpf: Prevent memory disambiguation attack
x86/bugs: Rename SSBD_NO to SSB_NO
KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
x86/bugs: Rework spec_ctrl base and mask logic
x86/bugs: Remove x86_spec_ctrl_set()
x86/bugs: Expose x86_spec_ctrl_base directly
x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
x86/speculation: Rework speculative_store_bypass_update()
x86/speculation: Add virtualized speculative store bypass disable support
x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
x86/speculation: Handle HT correctly on AMD
x86/cpufeatures: Add FEATURE_ZEN
x86/cpufeatures: Disentangle SSBD enumeration
x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
KVM: SVM: Move spec control call after restore of GS
x86/cpu: Make alternative_msr_write work for 32-bit code
x86/bugs: Fix the parameters alignment and missing void
x86/bugs: Make cpu_show_common() static
...
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.
...
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
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
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>
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>
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>
In the following commit:
6b55c9654f ("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>
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>
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: 2f857d0460 ("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>
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: 2f857d0460 ("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>
`e' is being freed twice.
Fix this by removing one of the kfree() calls.
Addresses-Coverity-ID: 1468983 ("Double free")
Fixes: 8111038444 ("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>
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: e5cd3abcb3 ("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>
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>
