- Fix a function comparison warning for a xen trace event macro
- Fix a double perf_event linking to a trace_uprobe_filter for multiple events
- Fix suspicious RCU warnings in trace event code for using
list_for_each_entry_rcu() when the "_rcu" portion wasn't needed.
- Fix a bug in the histogram code when using the same variable
- Fix a NULL pointer dereference when tracefs lockdown enabled and calling
trace_set_default_clock()
This v2 version contains:
- A fix to a bug found with the double perf_event linking patch
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Merge tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Various tracing fixes:
- Fix a function comparison warning for a xen trace event macro
- Fix a double perf_event linking to a trace_uprobe_filter for
multiple events
- Fix suspicious RCU warnings in trace event code for using
list_for_each_entry_rcu() when the "_rcu" portion wasn't needed.
- Fix a bug in the histogram code when using the same variable
- Fix a NULL pointer dereference when tracefs lockdown enabled and
calling trace_set_default_clock()
- A fix to a bug found with the double perf_event linking patch"
* tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/uprobe: Fix to make trace_uprobe_filter alignment safe
tracing: Do not set trace clock if tracefs lockdown is in effect
tracing: Fix histogram code when expression has same var as value
tracing: trigger: Replace unneeded RCU-list traversals
tracing/uprobe: Fix double perf_event linking on multiprobe uprobe
tracing: xen: Ordered comparison of function pointers
Prevent the kernel from crashing during resume from hibernation
if free pages contain leftover data from the restore kernel and
init_on_free is set (Alexander Potapenko).
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Merge tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki:
"Prevent the kernel from crashing during resume from hibernation if
free pages contain leftover data from the restore kernel and
init_on_free is set (Alexander Potapenko)"
* tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM: hibernate: fix crashes with init_on_free=1
Alexei Starovoitov says:
====================
pull-request: bpf-next 2020-01-22
The following pull-request contains BPF updates for your *net-next* tree.
We've added 92 non-merge commits during the last 16 day(s) which contain
a total of 320 files changed, 7532 insertions(+), 1448 deletions(-).
The main changes are:
1) function by function verification and program extensions from Alexei.
2) massive cleanup of selftests/bpf from Toke and Andrii.
3) batched bpf map operations from Brian and Yonghong.
4) tcp congestion control in bpf from Martin.
5) bulking for non-map xdp_redirect form Toke.
6) bpf_send_signal_thread helper from Yonghong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a helper to read the 64bit jiffies. It will be used
in a later patch to implement the bpf_cubic.c.
The helper is inlined for jit_requested and 64 BITS_PER_LONG
as the map_gen_lookup(). Other cases could be considered together
with map_gen_lookup() if needed.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200122233646.903260-1-kafai@fb.com
Introduce dynamic program extensions. The users can load additional BPF
functions and replace global functions in previously loaded BPF programs while
these programs are executing.
Global functions are verified individually by the verifier based on their types only.
Hence the global function in the new program which types match older function can
safely replace that corresponding function.
This new function/program is called 'an extension' of old program. At load time
the verifier uses (attach_prog_fd, attach_btf_id) pair to identify the function
to be replaced. The BPF program type is derived from the target program into
extension program. Technically bpf_verifier_ops is copied from target program.
The BPF_PROG_TYPE_EXT program type is a placeholder. It has empty verifier_ops.
The extension program can call the same bpf helper functions as target program.
Single BPF_PROG_TYPE_EXT type is used to extend XDP, SKB and all other program
types. The verifier allows only one level of replacement. Meaning that the
extension program cannot recursively extend an extension. That also means that
the maximum stack size is increasing from 512 to 1024 bytes and maximum
function nesting level from 8 to 16. The programs don't always consume that
much. The stack usage is determined by the number of on-stack variables used by
the program. The verifier could have enforced 512 limit for combined original
plus extension program, but it makes for difficult user experience. The main
use case for extensions is to provide generic mechanism to plug external
programs into policy program or function call chaining.
BPF trampoline is used to track both fentry/fexit and program extensions
because both are using the same nop slot at the beginning of every BPF
function. Attaching fentry/fexit to a function that was replaced is not
allowed. The opposite is true as well. Replacing a function that currently
being analyzed with fentry/fexit is not allowed. The executable page allocated
by BPF trampoline is not used by program extensions. This inefficiency will be
optimized in future patches.
Function by function verification of global function supports scalars and
pointer to context only. Hence program extensions are supported for such class
of global functions only. In the future the verifier will be extended with
support to pointers to structures, arrays with sizes, etc.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200121005348.2769920-2-ast@kernel.org
Commit 99c9a923e9 ("tracing/uprobe: Fix double perf_event
linking on multiprobe uprobe") moved trace_uprobe_filter on
trace_probe_event. However, since it introduced a flexible
data structure with char array and type casting, the
alignment of trace_uprobe_filter can be broken.
This changes the type of the array to trace_uprobe_filter
data strucure to fix it.
Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net
Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2
Fixes: 99c9a923e9 ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Restore the 'if (env->cur_state)' check that was incorrectly removed during
code move. Under memory pressure env->cur_state can be freed and zeroed inside
do_check(). Hence the check is necessary.
Fixes: 51c39bb1d5 ("bpf: Introduce function-by-function verification")
Reported-by: syzbot+b296579ba5015704d9fa@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200122024138.3385590-1-ast@kernel.org
Though the second half of trampoline page is unused a task could be
preempted in the middle of the first half of trampoline and two
updates to trampoline would change the code from underneath the
preempted task. Hence wait for tasks to voluntarily schedule or go
to userspace. Add similar wait before freeing the trampoline.
Fixes: fec56f5890 ("bpf: Introduce BPF trampoline")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/bpf/20200121032231.3292185-1-ast@kernel.org
kernel/bpf/inode.c misuses kern_path...() - it's much simpler (and
more efficient, on top of that) to use user_path...() counterparts
rather than bothering with doing getname() manually.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200120232858.GF8904@ZenIV.linux.org.uk
Generic update/delete batch ops functions were using __bpf_copy_key
without properly freeing the memory. Handle the memory allocation and
copy_from_user separately.
Fixes: aa2e93b8e5 ("bpf: Add generic support for update and delete batch ops")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200119194040.128369-1-brianvv@google.com
When trace_clock option is not set and unstable clcok detected,
tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of
case). In that case, if lockdown is in effect, null pointer
dereference error happens in ring_buffer_set_clock().
Link: http://lkml.kernel.org/r/20200116131236.3866925-1-masami256@gmail.com
Cc: stable@vger.kernel.org
Fixes: 17911ff38a ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1788488
Signed-off-by: Masami Ichikawa <masami256@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:
# echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
# echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
Would not display any histograms in the sched_switch histogram side.
But if I were to swap the location of
"delta=common_timestamp-$start" with "start2=$start"
Such that the last line had:
# echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger
The histogram works as expected.
What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:
delta=common_timestamp-$start
The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.
When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.
From Tom Zanussi:
"Just to clarify some more about what the problem was is that without
your patch, we would have two separate references to the same variable,
and during resolve_var_refs(), they'd both want to be resolved
separately, so in this case, since the first reference to start wasn't
part of an expression, it wouldn't get the read-once flag set, so would
be read normally, and then the second reference would do the read-once
read and also be read but using read-once. So everything worked and
you didn't see a problem:
from: start2=$start,delta=common_timestamp-$start
In the second case, when you switched them around, the first reference
would be resolved by doing the read-once, and following that the second
reference would try to resolve and see that the variable had already
been read, so failed as unset, which caused it to short-circuit out and
not do the trigger action to generate the synthetic event:
to: delta=common_timestamp-$start,start2=$start
With your patch, we only have the single resolution which happens
correctly the one time it's resolved, so this can't happen."
Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull networking fixes from David Miller:
1) Fix non-blocking connect() in x25, from Martin Schiller.
2) Fix spurious decryption errors in kTLS, from Jakub Kicinski.
3) Netfilter use-after-free in mtype_destroy(), from Cong Wang.
4) Limit size of TSO packets properly in lan78xx driver, from Eric
Dumazet.
5) r8152 probe needs an endpoint sanity check, from Johan Hovold.
6) Prevent looping in tcp_bpf_unhash() during sockmap/tls free, from
John Fastabend.
7) hns3 needs short frames padded on transmit, from Yunsheng Lin.
8) Fix netfilter ICMP header corruption, from Eyal Birger.
9) Fix soft lockup when low on memory in hns3, from Yonglong Liu.
10) Fix NTUPLE firmware command failures in bnxt_en, from Michael Chan.
11) Fix memory leak in act_ctinfo, from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
cxgb4: reject overlapped queues in TC-MQPRIO offload
cxgb4: fix Tx multi channel port rate limit
net: sched: act_ctinfo: fix memory leak
bnxt_en: Do not treat DSN (Digital Serial Number) read failure as fatal.
bnxt_en: Fix ipv6 RFS filter matching logic.
bnxt_en: Fix NTUPLE firmware command failures.
net: systemport: Fixed queue mapping in internal ring map
net: dsa: bcm_sf2: Configure IMP port for 2Gb/sec
net: dsa: sja1105: Don't error out on disabled ports with no phy-mode
net: phy: dp83867: Set FORCE_LINK_GOOD to default after reset
net: hns: fix soft lockup when there is not enough memory
net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()
net/sched: act_ife: initalize ife->metalist earlier
netfilter: nat: fix ICMP header corruption on ICMP errors
net: wan: lapbether.c: Use built-in RCU list checking
netfilter: nf_tables: fix flowtable list del corruption
netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks()
netfilter: nf_tables: remove WARN and add NLA_STRING upper limits
netfilter: nft_tunnel: ERSPAN_VERSION must not be null
netfilter: nft_tunnel: fix null-attribute check
...
Pull timer fixes from Ingo Molnar:
"Three fixes: fix link failure on Alpha, fix a Sparse warning and
annotate/robustify a lockless access in the NOHZ code"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/sched: Annotate lockless access to last_jiffies_update
lib/vdso: Make __cvdso_clock_getres() static
time/posix-stubs: Provide compat itimer supoprt for alpha
Pull cpu/SMT fix from Ingo Molnar:
"Fix a build bug on CONFIG_HOTPLUG_SMT=y && !CONFIG_SYSFS kernels"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/SMT: Fix x86 link error without CONFIG_SYSFS
Pull perf fixes from Ingo Molnar:
"Tooling fixes, three Intel uncore driver fixes, plus an AUX events fix
uncovered by the perf fuzzer"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Remove PCIe3 unit for SNR
perf/x86/intel/uncore: Fix missing marker for snr_uncore_imc_freerunning_events
perf/x86/intel/uncore: Add PCI ID of IMC for Xeon E3 V5 Family
perf: Correctly handle failed perf_get_aux_event()
perf hists: Fix variable name's inconsistency in hists__for_each() macro
perf map: Set kmap->kmaps backpointer for main kernel map chunks
perf report: Fix incorrectly added dimensions as switch perf data file
tools lib traceevent: Fix memory leakage in filter_event
Pull locking fixes from Ingo Molnar:
"Three fixes:
- Fix an rwsem spin-on-owner crash, introduced in v5.4
- Fix a lockdep bug when running out of stack_trace entries,
introduced in v5.4
- Docbook fix"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Fix kernel crash when spinning on RWSEM_OWNER_UNKNOWN
futex: Fix kernel-doc notation warning
locking/lockdep: Fix buffer overrun problem in stack_trace[]
Pull rseq fixes from Ingo Molnar:
"Two rseq bugfixes:
- CLONE_VM !CLONE_THREAD didn't work properly, the kernel would end
up corrupting the TLS of the parent. Technically a change in the
ABI but the previous behavior couldn't resonably have been relied
on by applications so this looks like a valid exception to the ABI
rule.
- Make the RSEQ_FLAG_UNREGISTER ABI behavior consistent with the
handling of other flags. This is not thought to impact any
applications either"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Unregister rseq for clone CLONE_VM
rseq: Reject unknown flags on rseq unregister
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Merge tag 'for-linus-2020-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull thread fixes from Christian Brauner:
"Here is an urgent fix for ptrace_may_access() permission checking.
Commit 69f594a389 ("ptrace: do not audit capability check when
outputing /proc/pid/stat") introduced the ability to opt out of audit
messages for accesses to various proc files since they are not
violations of policy.
While doing so it switched the check from ns_capable() to
has_ns_capability{_noaudit}(). That means it switched from checking
the subjective credentials (ktask->cred) of the task to using the
objective credentials (ktask->real_cred). This is appears to be wrong.
ptrace_has_cap() is currently only used in ptrace_may_access() And is
used to check whether the calling task (subject) has the
CAP_SYS_PTRACE capability in the provided user namespace to operate on
the target task (object). According to the cred.h comments this means
the subjective credentials of the calling task need to be used.
With this fix we switch ptrace_has_cap() to use security_capable() and
thus back to using the subjective credentials.
As one example where this might be particularly problematic, Jann
pointed out that in combination with the upcoming IORING_OP_OPENAT{2}
feature, this bug might allow unprivileged users to bypass the
capability checks while asynchronously opening files like /proc/*/mem,
because the capability checks for this would be performed against
kernel credentials.
To illustrate on the former point about this being exploitable: When
io_uring creates a new context it records the subjective credentials
of the caller. Later on, when it starts to do work it creates a kernel
thread and registers a callback. The callback runs with kernel creds
for ktask->real_cred and ktask->cred.
To prevent this from becoming a full-blown 0-day io_uring will call
override_cred() and override ktask->cred with the subjective
credentials of the creator of the io_uring instance. With
ptrace_has_cap() currently looking at ktask->real_cred this override
will be ineffective and the caller will be able to open arbitray proc
files as mentioned above.
Luckily, this is currently not exploitable but would be so once
IORING_OP_OPENAT{2} land in v5.6. Let's fix it now.
To minimize potential regressions I successfully ran the criu
testsuite. criu makes heavy use of ptrace() and extensively hits
ptrace_may_access() codepaths and has a good change of detecting any
regressions.
Additionally, I succesfully ran the ptrace and seccomp kernel tests"
* tag 'for-linus-2020-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()
Commit 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
introduced the ability to opt out of audit messages for accesses to various
proc files since they are not violations of policy. While doing so it
somehow switched the check from ns_capable() to
has_ns_capability{_noaudit}(). That means it switched from checking the
subjective credentials of the task to using the objective credentials. This
is wrong since. ptrace_has_cap() is currently only used in
ptrace_may_access() And is used to check whether the calling task (subject)
has the CAP_SYS_PTRACE capability in the provided user namespace to operate
on the target task (object). According to the cred.h comments this would
mean the subjective credentials of the calling task need to be used.
This switches ptrace_has_cap() to use security_capable(). Because we only
call ptrace_has_cap() in ptrace_may_access() and in there we already have a
stable reference to the calling task's creds under rcu_read_lock() there's
no need to go through another series of dereferences and rcu locking done
in ns_capable{_noaudit}().
As one example where this might be particularly problematic, Jann pointed
out that in combination with the upcoming IORING_OP_OPENAT feature, this
bug might allow unprivileged users to bypass the capability checks while
asynchronously opening files like /proc/*/mem, because the capability
checks for this would be performed against kernel credentials.
To illustrate on the former point about this being exploitable: When
io_uring creates a new context it records the subjective credentials of the
caller. Later on, when it starts to do work it creates a kernel thread and
registers a callback. The callback runs with kernel creds for
ktask->real_cred and ktask->cred. To prevent this from becoming a
full-blown 0-day io_uring will call override_cred() and override
ktask->cred with the subjective credentials of the creator of the io_uring
instance. With ptrace_has_cap() currently looking at ktask->real_cred this
override will be ineffective and the caller will be able to open arbitray
proc files as mentioned above.
Luckily, this is currently not exploitable but will turn into a 0-day once
IORING_OP_OPENAT{2} land in v5.6. Fix it now!
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Jann Horn <jannh@google.com>
Fixes: 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Vince reports a worrying issue:
| so I was tracking down some odd behavior in the perf_fuzzer which turns
| out to be because perf_even_open() sometimes returns 0 (indicating a file
| descriptor of 0) even though as far as I can tell stdin is still open.
... and further the cause:
| error is triggered if aux_sample_size has non-zero value.
|
| seems to be this line in kernel/events/core.c:
|
| if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader))
| goto err_locked;
|
| (note, err is never set)
This seems to be a thinko in commit:
ab43762ef0 ("perf: Allow normal events to output AUX data")
... and we should probably return -EINVAL here, as this should only
happen when the new event is mis-configured or does not have a
compatible aux_event group leader.
Fixes: ab43762ef0 ("perf: Allow normal events to output AUX data")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
The commit 91d2a812df ("locking/rwsem: Make handoff writer
optimistically spin on owner") will allow a recently woken up waiting
writer to spin on the owner. Unfortunately, if the owner happens to be
RWSEM_OWNER_UNKNOWN, the code will incorrectly spin on it leading to a
kernel crash. This is fixed by passing the proper non-spinnable bits
to rwsem_spin_on_owner() so that RWSEM_OWNER_UNKNOWN will be treated
as a non-spinnable target.
Fixes: 91d2a812df ("locking/rwsem: Make handoff writer optimistically spin on owner")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200115154336.8679-1-longman@redhat.com
kernel/bpf/syscall.c: In function generic_map_lookup_batch:
kernel/bpf/syscall.c:1339:7: warning: variable first_key set but not used [-Wunused-but-set-variable]
It is never used, so remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Brian Vazquez <brianvv@google.com>
Link: https://lore.kernel.org/bpf/20200116145300.59056-1-yuehaibing@huawei.com
Now that we don't have a reference to a devmap when flushing the device
bulk queue, let's change the the devmap_xmit tracepoint to remote the
map_id and map_index fields entirely. Rearrange the fields so 'drops' and
'sent' stay in the same position in the tracepoint struct, to make it
possible for the xdp_monitor utility to read both the old and the new
format.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/157918768613.1458396.9165902403373826572.stgit@toke.dk
Since the bulk queue used by XDP_REDIRECT now lives in struct net_device,
we can re-use the bulking for the non-map version of the bpf_redirect()
helper. This is a simple matter of having xdp_do_redirect_slow() queue the
frame on the bulk queue instead of sending it out with __bpf_tx_xdp().
Unfortunately we can't make the bpf_redirect() helper return an error if
the ifindex doesn't exit (as bpf_redirect_map() does), because we don't
have a reference to the network namespace of the ingress device at the time
the helper is called. So we have to leave it as-is and keep the device
lookup in xdp_do_redirect_slow().
Since this leaves less reason to have the non-map redirect code in a
separate function, so we get rid of the xdp_do_redirect_slow() function
entirely. This does lose us the tracepoint disambiguation, but fortunately
the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint
entry structures. This means both can contain a map index, so we can just
amend the tracepoint definitions so we always emit the xdp_redirect(_err)
tracepoints, but with the map ID only populated if a map is present. This
means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep
the definitions around in case someone is still listening for them.
With this change, the performance of the xdp_redirect sample program goes
from 5Mpps to 8.4Mpps (a 68% increase).
Since the flush functions are no longer map-specific, rename the flush()
functions to drop _map from their names. One of the renamed functions is
the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To
keep from having to update all drivers, use a #define to keep the old name
working, and only update the virtual drivers in this patch.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
Commit 96360004b8 ("xdp: Make devmap flush_list common for all map
instances"), changed devmap flushing to be a global operation instead of a
per-map operation. However, the queue structure used for bulking was still
allocated as part of the containing map.
This patch moves the devmap bulk queue into struct net_device. The
motivation for this is reusing it for the non-map variant of XDP_REDIRECT,
which will be changed in a subsequent commit. To avoid other fields of
struct net_device moving to different cache lines, we also move a couple of
other members around.
We defer the actual allocation of the bulk queue structure until the
NETDEV_REGISTER notification devmap.c. This makes it possible to check for
ndo_xdp_xmit support before allocating the structure, which is not possible
at the time struct net_device is allocated. However, we keep the freeing in
free_netdev() to avoid adding another RCU callback on NETDEV_UNREGISTER.
Because of this change, we lose the reference back to the map that
originated the redirect, so change the tracepoint to always return 0 as the
map ID and index. Otherwise no functional change is intended with this
patch.
After this patch, the relevant part of struct net_device looks like this,
according to pahole:
/* --- cacheline 14 boundary (896 bytes) --- */
struct netdev_queue * _tx __attribute__((__aligned__(64))); /* 896 8 */
unsigned int num_tx_queues; /* 904 4 */
unsigned int real_num_tx_queues; /* 908 4 */
struct Qdisc * qdisc; /* 912 8 */
unsigned int tx_queue_len; /* 920 4 */
spinlock_t tx_global_lock; /* 924 4 */
struct xdp_dev_bulk_queue * xdp_bulkq; /* 928 8 */
struct xps_dev_maps * xps_cpus_map; /* 936 8 */
struct xps_dev_maps * xps_rxqs_map; /* 944 8 */
struct mini_Qdisc * miniq_egress; /* 952 8 */
/* --- cacheline 15 boundary (960 bytes) --- */
struct hlist_head qdisc_hash[16]; /* 960 128 */
/* --- cacheline 17 boundary (1088 bytes) --- */
struct timer_list watchdog_timer; /* 1088 40 */
/* XXX last struct has 4 bytes of padding */
int watchdog_timeo; /* 1128 4 */
/* XXX 4 bytes hole, try to pack */
struct list_head todo_list; /* 1136 16 */
/* --- cacheline 18 boundary (1152 bytes) --- */
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768397.1458396.12673224324627072349.stgit@toke.dk
Upon resuming from hibernation, free pages may contain stale data from
the kernel that initiated the resume. This breaks the invariant
inflicted by init_on_free=1 that freed pages must be zeroed.
To deal with this problem, make clear_free_pages() also clear the free
pages when init_on_free is enabled.
Fixes: 6471384af2 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Reported-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Daniel Borkmann says:
====================
pull-request: bpf 2020-01-15
The following pull-request contains BPF updates for your *net* tree.
We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 13 files changed, 95 insertions(+), 43 deletions(-).
The main changes are:
1) Fix refcount leak for TCP time wait and request sockets for socket lookup
related BPF helpers, from Lorenz Bauer.
2) Fix wrong verification of ARSH instruction under ALU32, from Daniel Borkmann.
3) Batch of several sockmap and related TLS fixes found while operating
more complex BPF programs with Cilium and OpenSSL, from John Fastabend.
4) Fix sockmap to read psock's ingress_msg queue before regular sk_receive_queue()
to avoid purging data upon teardown, from Lingpeng Chen.
5) Fix printing incorrect pointer in bpftool's btf_dump_ptr() in order to properly
dump a BPF map's value with BTF, from Martin KaFai Lau.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
htab can't use generic batch support due some problematic behaviours
inherent to the data structre, i.e. while iterating the bpf map a
concurrent program might delete the next entry that batch was about to
use, in that case there's no easy solution to retrieve the next entry,
the issue has been discussed multiple times (see [1] and [2]).
The only way hmap can be traversed without the problem previously
exposed is by making sure that the map is traversing entire buckets.
This commit implements those strict requirements for hmap, the
implementation follows the same interaction that generic support with
some exceptions:
- If keys/values buffer are not big enough to traverse a bucket,
ENOSPC will be returned.
- out_batch contains the value of the next bucket in the iteration, not
the next key, but this is transparent for the user since the user
should never use out_batch for other than bpf batch syscalls.
This commits implements BPF_MAP_LOOKUP_BATCH and adds support for new
command BPF_MAP_LOOKUP_AND_DELETE_BATCH. Note that for update/delete
batch ops it is possible to use the generic implementations.
[1] https://lore.kernel.org/bpf/20190724165803.87470-1-brianvv@google.com/
[2] https://lore.kernel.org/bpf/20190906225434.3635421-1-yhs@fb.com/
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-6-brianvv@google.com
This adds the generic batch ops functionality to bpf arraymap, note that
since deletion is not a valid operation for arraymap, only batch and
lookup are added.
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200115184308.162644-5-brianvv@google.com
This commit adds generic support for update and delete batch ops that
can be used for almost all the bpf maps. These commands share the same
UAPI attr that lookup and lookup_and_delete batch ops use and the
syscall commands are:
BPF_MAP_UPDATE_BATCH
BPF_MAP_DELETE_BATCH
The main difference between update/delete and lookup batch ops is that
for update/delete keys/values must be specified for userspace and
because of that, neither in_batch nor out_batch are used.
Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-4-brianvv@google.com
This commit introduces generic support for the bpf_map_lookup_batch.
This implementation can be used by almost all the bpf maps since its core
implementation is relying on the existing map_get_next_key and
map_lookup_elem. The bpf syscall subcommand introduced is:
BPF_MAP_LOOKUP_BATCH
The UAPI attribute is:
struct { /* struct used by BPF_MAP_*_BATCH commands */
__aligned_u64 in_batch; /* start batch,
* NULL to start from beginning
*/
__aligned_u64 out_batch; /* output: next start batch */
__aligned_u64 keys;
__aligned_u64 values;
__u32 count; /* input/output:
* input: # of key/value
* elements
* output: # of filled elements
*/
__u32 map_fd;
__u64 elem_flags;
__u64 flags;
} batch;
in_batch/out_batch are opaque values use to communicate between
user/kernel space, in_batch/out_batch must be of key_size length.
To start iterating from the beginning in_batch must be null,
count is the # of key/value elements to retrieve. Note that the 'keys'
buffer must be a buffer of key_size * count size and the 'values' buffer
must be value_size * count, where value_size must be aligned to 8 bytes
by userspace if it's dealing with percpu maps. 'count' will contain the
number of keys/values successfully retrieved. Note that 'count' is an
input/output variable and it can contain a lower value after a call.
If there's no more entries to retrieve, ENOENT will be returned. If error
is ENOENT, count might be > 0 in case it copied some values but there were
no more entries to retrieve.
Note that if the return code is an error and not -EFAULT,
count indicates the number of elements successfully processed.
Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-3-brianvv@google.com
This commit moves reusable code from map_lookup_elem and map_update_elem
to avoid code duplication in kernel/bpf/syscall.c.
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200115184308.162644-2-brianvv@google.com
Anatoly has been fuzzing with kBdysch harness and reported a hang in one
of the outcomes:
0: R1=ctx(id=0,off=0,imm=0) R10=fp0
0: (85) call bpf_get_socket_cookie#46
1: R0_w=invP(id=0) R10=fp0
1: (57) r0 &= 808464432
2: R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
2: (14) w0 -= 810299440
3: R0_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
3: (c4) w0 s>>= 1
4: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
4: (76) if w0 s>= 0x30303030 goto pc+216
221: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
221: (95) exit
processed 6 insns (limit 1000000) [...]
Taking a closer look, the program was xlated as follows:
# ./bpftool p d x i 12
0: (85) call bpf_get_socket_cookie#7800896
1: (bf) r6 = r0
2: (57) r6 &= 808464432
3: (14) w6 -= 810299440
4: (c4) w6 s>>= 1
5: (76) if w6 s>= 0x30303030 goto pc+216
6: (05) goto pc-1
7: (05) goto pc-1
8: (05) goto pc-1
[...]
220: (05) goto pc-1
221: (05) goto pc-1
222: (95) exit
Meaning, the visible effect is very similar to f54c7898ed ("bpf: Fix
precision tracking for unbounded scalars"), that is, the fall-through
branch in the instruction 5 is considered to be never taken given the
conclusion from the min/max bounds tracking in w6, and therefore the
dead-code sanitation rewrites it as goto pc-1. However, real-life input
disagrees with verification analysis since a soft-lockup was observed.
The bug sits in the analysis of the ARSH. The definition is that we shift
the target register value right by K bits through shifting in copies of
its sign bit. In adjust_scalar_min_max_vals(), we do first coerce the
register into 32 bit mode, same happens after simulating the operation.
However, for the case of simulating the actual ARSH, we don't take the
mode into account and act as if it's always 64 bit, but location of sign
bit is different:
dst_reg->smin_value >>= umin_val;
dst_reg->smax_value >>= umin_val;
dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val);
Consider an unknown R0 where bpf_get_socket_cookie() (or others) would
for example return 0xffff. With the above ARSH simulation, we'd see the
following results:
[...]
1: R1=ctx(id=0,off=0,imm=0) R2_w=invP65535 R10=fp0
1: (85) call bpf_get_socket_cookie#46
2: R0_w=invP(id=0) R10=fp0
2: (57) r0 &= 808464432
-> R0_runtime = 0x3030
3: R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
3: (14) w0 -= 810299440
-> R0_runtime = 0xcfb40000
4: R0_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
(0xffffffff)
4: (c4) w0 s>>= 1
-> R0_runtime = 0xe7da0000
5: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
(0x67c00000) (0x7ffbfff8)
[...]
In insn 3, we have a runtime value of 0xcfb40000, which is '1100 1111 1011
0100 0000 0000 0000 0000', the result after the shift has 0xe7da0000 that
is '1110 0111 1101 1010 0000 0000 0000 0000', where the sign bit is correctly
retained in 32 bit mode. In insn4, the umax was 0xffffffff, and changed into
0x7ffbfff8 after the shift, that is, '0111 1111 1111 1011 1111 1111 1111 1000'
and means here that the simulation didn't retain the sign bit. With above
logic, the updates happen on the 64 bit min/max bounds and given we coerced
the register, the sign bits of the bounds are cleared as well, meaning, we
need to force the simulation into s32 space for 32 bit alu mode.
Verification after the fix below. We're first analyzing the fall-through branch
on 32 bit signed >= test eventually leading to rejection of the program in this
specific case:
0: R1=ctx(id=0,off=0,imm=0) R10=fp0
0: (b7) r2 = 808464432
1: R1=ctx(id=0,off=0,imm=0) R2_w=invP808464432 R10=fp0
1: (85) call bpf_get_socket_cookie#46
2: R0_w=invP(id=0) R10=fp0
2: (bf) r6 = r0
3: R0_w=invP(id=0) R6_w=invP(id=0) R10=fp0
3: (57) r6 &= 808464432
4: R0_w=invP(id=0) R6_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
4: (14) w6 -= 810299440
5: R0_w=invP(id=0) R6_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
5: (c4) w6 s>>= 1
6: R0_w=invP(id=0) R6_w=invP(id=0,umin_value=3888119808,umax_value=4294705144,var_off=(0xe7c00000; 0x183bfff8)) R10=fp0
(0x67c00000) (0xfffbfff8)
6: (76) if w6 s>= 0x30303030 goto pc+216
7: R0_w=invP(id=0) R6_w=invP(id=0,umin_value=3888119808,umax_value=4294705144,var_off=(0xe7c00000; 0x183bfff8)) R10=fp0
7: (30) r0 = *(u8 *)skb[808464432]
BPF_LD_[ABS|IND] uses reserved fields
processed 8 insns (limit 1000000) [...]
Fixes: 9cbe1f5a32 ("bpf/verifier: improve register value range tracking with ARSH")
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115204733.16648-1-daniel@iogearbox.net
Commit 8b401f9ed2 ("bpf: implement bpf_send_signal() helper")
added helper bpf_send_signal() which permits bpf program to
send a signal to the current process. The signal may be
delivered to any threads in the process.
We found a use case where sending the signal to the current
thread is more preferable.
- A bpf program will collect the stack trace and then
send signal to the user application.
- The user application will add some thread specific
information to the just collected stack trace for
later analysis.
If bpf_send_signal() is used, user application will need
to check whether the thread receiving the signal matches
the thread collecting the stack by checking thread id.
If not, it will need to send signal to another thread
through pthread_kill().
This patch proposed a new helper bpf_send_signal_thread(),
which sends the signal to the thread corresponding to
the current kernel task. This way, user space is guaranteed that
bpf_program execution context and user space signal handling
context are the same thread.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115035002.602336-1-yhs@fb.com
With CONFIG_PROVE_RCU_LIST, I had many suspicious RCU warnings
when I ran ftracetest trigger testcases.
-----
# dmesg -c > /dev/null
# ./ftracetest test.d/trigger
...
# dmesg | grep "RCU-list traversed" | cut -f 2 -d ] | cut -f 2 -d " "
kernel/trace/trace_events_hist.c:6070
kernel/trace/trace_events_hist.c:1760
kernel/trace/trace_events_hist.c:5911
kernel/trace/trace_events_trigger.c:504
kernel/trace/trace_events_hist.c:1810
kernel/trace/trace_events_hist.c:3158
kernel/trace/trace_events_hist.c:3105
kernel/trace/trace_events_hist.c:5518
kernel/trace/trace_events_hist.c:5998
kernel/trace/trace_events_hist.c:6019
kernel/trace/trace_events_hist.c:6044
kernel/trace/trace_events_trigger.c:1500
kernel/trace/trace_events_trigger.c:1540
kernel/trace/trace_events_trigger.c:539
kernel/trace/trace_events_trigger.c:584
-----
I investigated those warnings and found that the RCU-list
traversals in event trigger and hist didn't need to use
RCU version because those were called only under event_mutex.
I also checked other RCU-list traversals related to event
trigger list, and found that most of them were called from
event_hist_trigger_func() or hist_unregister_trigger() or
register/unregister functions except for a few cases.
Replace these unneeded RCU-list traversals with normal list
traversal macro and lockdep_assert_held() to check the
event_mutex is held.
Link: http://lkml.kernel.org/r/157680910305.11685.15110237954275915782.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 30350d65ac ("tracing: Add variable support to hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix double perf_event linking to trace_uprobe_filter on
multiple uprobe event by moving trace_uprobe_filter under
trace_probe_event.
In uprobe perf event, trace_uprobe_filter data structure is
managing target mm filters (in perf_event) related to each
uprobe event.
Since commit 60d53e2c3b ("tracing/probe: Split trace_event
related data from trace_probe") left the trace_uprobe_filter
data structure in trace_uprobe, if a trace_probe_event has
multiple trace_uprobe (multi-probe event), a perf_event is
added to different trace_uprobe_filter on each trace_uprobe.
This leads a linked list corruption.
To fix this issue, move trace_uprobe_filter to trace_probe_event
and link it once on each event instead of each probe.
Link: http://lkml.kernel.org/r/157862073931.1800.3800576241181489174.stgit@devnote2
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?b?w7hyZ2Vuc2Vu?= <thoiland@redhat.com>
Cc: Jean-Tsung Hsiao <jhsiao@redhat.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Link: https://lkml.kernel.org/r/20200108171611.GA8472@kernel.org
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Merge misc fixes from David Howells.
Two afs fixes and a key refcounting fix.
* dhowells:
afs: Fix afs_lookup() to not clobber the version on a new dentry
afs: Fix use-after-loss-of-ref
keys: Fix request_key() cache
Instead of using bpf_struct_ops_map_lookup_elem() which is
not implemented, bpf_struct_ops_map_seq_show_elem() should
also use bpf_struct_ops_map_sys_lookup_elem() which does
an inplace update to the value. The change allocates
a value to pass to bpf_struct_ops_map_sys_lookup_elem().
[root@arch-fb-vm1 bpf]# cat /sys/fs/bpf/dctcp
{{{1}},BPF_STRUCT_OPS_STATE_INUSE,{{00000000df93eebc,00000000df93eebc},0,2, ...
Fixes: 85d33df357 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200114072647.3188298-1-kafai@fb.com
When the key cached by request_key() and co. is cleaned up on exit(),
the code looks in the wrong task_struct, and so clears the wrong cache.
This leads to anomalies in key refcounting when doing, say, a kernel
build on an afs volume, that then trigger kasan to report a
use-after-free when the key is viewed in /proc/keys.
Fix this by making exit_creds() look in the passed-in task_struct rather
than in current (the task_struct cleanup code is deferred by RCU and
potentially run in another task).
Fixes: 7743c48e54 ("keys: Cache result of request_key*() temporarily in task_struct")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull thread fixes from Christian Brauner:
"This contains a series of patches to fix CLONE_SETTLS when used with
clone3().
The clone3() syscall passes the tls argument through struct clone_args
instead of a register. This means, all architectures that do not
implement copy_thread_tls() but still support CLONE_SETTLS via
copy_thread() expecting the tls to be located in a register argument
based on clone() are currently unfortunately broken. Their tls value
will be garbage.
The patch series fixes this on all architectures that currently define
__ARCH_WANT_SYS_CLONE3. It also adds a compile-time check to ensure
that any architecture that enables clone3() in the future is forced to
also implement copy_thread_tls().
My ultimate goal is to get rid of the copy_thread()/copy_thread_tls()
split and just have copy_thread_tls() at some point in the not too
distant future (Maybe even renaming copy_thread_tls() back to simply
copy_thread() once the old function is ripped from all arches). This
is dependent now on all arches supporting clone3().
While all relevant arches do that now there are still four missing:
ia64, m68k, sh and sparc. They have the system call reserved, but not
implemented. Once they all implement clone3() we can get rid of
ARCH_WANT_SYS_CLONE3 and HAVE_COPY_THREAD_TLS.
This series also includes a minor fix for the arm64 uapi headers which
caused __NR_clone3 to be missing from the exported user headers.
Unfortunately the series came in a little late especially given that
it touches a range of architectures. Due to the holidays not all arch
maintainers responded in time probably due to their backlog. Will and
Arnd have thankfully acked the arm specific changes.
Given that the changes are straightforward and rather minimal combined
with the fact the that clone3() with CLONE_SETTLS is broken I decided
to send them post rc3 nonetheless"
* tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
um: Implement copy_thread_tls
clone3: ensure copy_thread_tls is implemented
xtensa: Implement copy_thread_tls
riscv: Implement copy_thread_tls
parisc: Implement copy_thread_tls
arm: Implement copy_thread_tls
arm64: Implement copy_thread_tls
arm64: Move __ARCH_WANT_SYS_CLONE3 definition to uapi headers
New llvm and old llvm with libbpf help produce BTF that distinguish global and
static functions. Unlike arguments of static function the arguments of global
functions cannot be removed or optimized away by llvm. The compiler has to use
exactly the arguments specified in a function prototype. The argument type
information allows the verifier validate each global function independently.
For now only supported argument types are pointer to context and scalars. In
the future pointers to structures, sizes, pointer to packet data can be
supported as well. Consider the following example:
static int f1(int ...)
{
...
}
int f3(int b);
int f2(int a)
{
f1(a) + f3(a);
}
int f3(int b)
{
...
}
int main(...)
{
f1(...) + f2(...) + f3(...);
}
The verifier will start its safety checks from the first global function f2().
It will recursively descend into f1() because it's static. Then it will check
that arguments match for the f3() invocation inside f2(). It will not descend
into f3(). It will finish f2() that has to be successfully verified for all
possible values of 'a'. Then it will proceed with f3(). That function also has
to be safe for all possible values of 'b'. Then it will start subprog 0 (which
is main() function). It will recursively descend into f1() and will skip full
check of f2() and f3(), since they are global. The order of processing global
functions doesn't affect safety, since all global functions must be proven safe
based on their arguments only.
Such function by function verification can drastically improve speed of the
verification and reduce complexity.
Note that the stack limit of 512 still applies to the call chain regardless whether
functions were static or global. The nested level of 8 also still applies. The
same recursion prevention checks are in place as well.
The type information and static/global kind is preserved after the verification
hence in the above example global function f2() and f3() can be replaced later
by equivalent functions with the same types that are loaded and verified later
without affecting safety of this main() program. Such replacement (re-linking)
of global functions is a subject of future patches.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-3-ast@kernel.org
The ungrafting from PRIO bug fixes in net, when merged into net-next,
merge cleanly but create a build failure. The resolution used here is
from Petr Machata.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Missing netns pointer init in arp_tables, from Florian Westphal.
2) Fix normal tcp SACK being treated as D-SACK, from Pengcheng Yang.
3) Fix divide by zero in sch_cake, from Wen Yang.
4) Len passed to skb_put_padto() is wrong in qrtr code, from Carl
Huang.
5) cmd->obj.chunk is leaked in sctp code error paths, from Xin Long.
6) cgroup bpf programs can be released out of order, fix from Roman
Gushchin.
7) Make sure stmmac debugfs entry name is changed when device name
changes, from Jiping Ma.
8) Fix memory leak in vlan_dev_set_egress_priority(), from Eric
Dumazet.
9) SKB leak in lan78xx usb driver, also from Eric Dumazet.
10) Ridiculous TCA_FQ_QUANTUM values configured can cause loops in fq
packet scheduler, reject them. From Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
tipc: fix wrong connect() return code
tipc: fix link overflow issue at socket shutdown
netfilter: ipset: avoid null deref when IPSET_ATTR_LINENO is present
netfilter: conntrack: dccp, sctp: handle null timeout argument
atm: eni: fix uninitialized variable warning
macvlan: do not assume mac_header is set in macvlan_broadcast()
net: sch_prio: When ungrafting, replace with FIFO
mlxsw: spectrum_qdisc: Ignore grafting of invisible FIFO
MAINTAINERS: Remove myself as co-maintainer for qcom-ethqos
gtp: fix bad unlock balance in gtp_encap_enable_socket
pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM
tipc: remove meaningless assignment in Makefile
tipc: do not add socket.o to tipc-y twice
net: stmmac: dwmac-sun8i: Allow all RGMII modes
net: stmmac: dwmac-sunxi: Allow all RGMII modes
net: usb: lan78xx: fix possible skb leak
net: stmmac: Fixed link does not need MDIO Bus
vlan: vlan_changelink() should propagate errors
vlan: fix memory leak in vlan_dev_set_egress_priority
stmmac: debugfs entry name is not be changed when udev rename device name.
...
Using compat_sys_getitimer and compat_sys_setitimer on alpha
causes a link failure in the Alpha tinyconfig and other configurations
that turn off CONFIG_POSIX_TIMERS.
Use the same #ifdef check for the stub version as well.
Fixes: 4c22ea2b91 ("y2038: use compat_{get,set}_itimer on alpha")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191207191043.656328-1-arnd@arndb.de
This patch makes "struct tcp_congestion_ops" to be the first user
of BPF STRUCT_OPS. It allows implementing a tcp_congestion_ops
in bpf.
The BPF implemented tcp_congestion_ops can be used like
regular kernel tcp-cc through sysctl and setsockopt. e.g.
[root@arch-fb-vm1 bpf]# sysctl -a | egrep congestion
net.ipv4.tcp_allowed_congestion_control = reno cubic bpf_cubic
net.ipv4.tcp_available_congestion_control = reno bic cubic bpf_cubic
net.ipv4.tcp_congestion_control = bpf_cubic
There has been attempt to move the TCP CC to the user space
(e.g. CCP in TCP). The common arguments are faster turn around,
get away from long-tail kernel versions in production...etc,
which are legit points.
BPF has been the continuous effort to join both kernel and
userspace upsides together (e.g. XDP to gain the performance
advantage without bypassing the kernel). The recent BPF
advancements (in particular BTF-aware verifier, BPF trampoline,
BPF CO-RE...) made implementing kernel struct ops (e.g. tcp cc)
possible in BPF. It allows a faster turnaround for testing algorithm
in the production while leveraging the existing (and continue growing)
BPF feature/framework instead of building one specifically for
userspace TCP CC.
This patch allows write access to a few fields in tcp-sock
(in bpf_tcp_ca_btf_struct_access()).
The optional "get_info" is unsupported now. It can be added
later. One possible way is to output the info with a btf-id
to describe the content.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003508.3856115-1-kafai@fb.com
The patch introduces BPF_MAP_TYPE_STRUCT_OPS. The map value
is a kernel struct with its func ptr implemented in bpf prog.
This new map is the interface to register/unregister/introspect
a bpf implemented kernel struct.
The kernel struct is actually embedded inside another new struct
(or called the "value" struct in the code). For example,
"struct tcp_congestion_ops" is embbeded in:
struct bpf_struct_ops_tcp_congestion_ops {
refcount_t refcnt;
enum bpf_struct_ops_state state;
struct tcp_congestion_ops data; /* <-- kernel subsystem struct here */
}
The map value is "struct bpf_struct_ops_tcp_congestion_ops".
The "bpftool map dump" will then be able to show the
state ("inuse"/"tobefree") and the number of subsystem's refcnt (e.g.
number of tcp_sock in the tcp_congestion_ops case). This "value" struct
is created automatically by a macro. Having a separate "value" struct
will also make extending "struct bpf_struct_ops_XYZ" easier (e.g. adding
"void (*init)(void)" to "struct bpf_struct_ops_XYZ" to do some
initialization works before registering the struct_ops to the kernel
subsystem). The libbpf will take care of finding and populating the
"struct bpf_struct_ops_XYZ" from "struct XYZ".
Register a struct_ops to a kernel subsystem:
1. Load all needed BPF_PROG_TYPE_STRUCT_OPS prog(s)
2. Create a BPF_MAP_TYPE_STRUCT_OPS with attr->btf_vmlinux_value_type_id
set to the btf id "struct bpf_struct_ops_tcp_congestion_ops" of the
running kernel.
Instead of reusing the attr->btf_value_type_id,
btf_vmlinux_value_type_id s added such that attr->btf_fd can still be
used as the "user" btf which could store other useful sysadmin/debug
info that may be introduced in the furture,
e.g. creation-date/compiler-details/map-creator...etc.
3. Create a "struct bpf_struct_ops_tcp_congestion_ops" object as described
in the running kernel btf. Populate the value of this object.
The function ptr should be populated with the prog fds.
4. Call BPF_MAP_UPDATE with the object created in (3) as
the map value. The key is always "0".
During BPF_MAP_UPDATE, the code that saves the kernel-func-ptr's
args as an array of u64 is generated. BPF_MAP_UPDATE also allows
the specific struct_ops to do some final checks in "st_ops->init_member()"
(e.g. ensure all mandatory func ptrs are implemented).
If everything looks good, it will register this kernel struct
to the kernel subsystem. The map will not allow further update
from this point.
Unregister a struct_ops from the kernel subsystem:
BPF_MAP_DELETE with key "0".
Introspect a struct_ops:
BPF_MAP_LOOKUP_ELEM with key "0". The map value returned will
have the prog _id_ populated as the func ptr.
The map value state (enum bpf_struct_ops_state) will transit from:
INIT (map created) =>
INUSE (map updated, i.e. reg) =>
TOBEFREE (map value deleted, i.e. unreg)
The kernel subsystem needs to call bpf_struct_ops_get() and
bpf_struct_ops_put() to manage the "refcnt" in the
"struct bpf_struct_ops_XYZ". This patch uses a separate refcnt
for the purose of tracking the subsystem usage. Another approach
is to reuse the map->refcnt and then "show" (i.e. during map_lookup)
the subsystem's usage by doing map->refcnt - map->usercnt to filter out
the map-fd/pinned-map usage. However, that will also tie down the
future semantics of map->refcnt and map->usercnt.
The very first subsystem's refcnt (during reg()) holds one
count to map->refcnt. When the very last subsystem's refcnt
is gone, it will also release the map->refcnt. All bpf_prog will be
freed when the map->refcnt reaches 0 (i.e. during map_free()).
Here is how the bpftool map command will look like:
[root@arch-fb-vm1 bpf]# bpftool map show
6: struct_ops name dctcp flags 0x0
key 4B value 256B max_entries 1 memlock 4096B
btf_id 6
[root@arch-fb-vm1 bpf]# bpftool map dump id 6
[{
"value": {
"refcnt": {
"refs": {
"counter": 1
}
},
"state": 1,
"data": {
"list": {
"next": 0,
"prev": 0
},
"key": 0,
"flags": 2,
"init": 24,
"release": 0,
"ssthresh": 25,
"cong_avoid": 30,
"set_state": 27,
"cwnd_event": 28,
"in_ack_event": 26,
"undo_cwnd": 29,
"pkts_acked": 0,
"min_tso_segs": 0,
"sndbuf_expand": 0,
"cong_control": 0,
"get_info": 0,
"name": [98,112,102,95,100,99,116,99,112,0,0,0,0,0,0,0
],
"owner": 0
}
}
}
]
Misc Notes:
* bpf_struct_ops_map_sys_lookup_elem() is added for syscall lookup.
It does an inplace update on "*value" instead returning a pointer
to syscall.c. Otherwise, it needs a separate copy of "zero" value
for the BPF_STRUCT_OPS_STATE_INIT to avoid races.
* The bpf_struct_ops_map_delete_elem() is also called without
preempt_disable() from map_delete_elem(). It is because
the "->unreg()" may requires sleepable context, e.g.
the "tcp_unregister_congestion_control()".
* "const" is added to some of the existing "struct btf_func_model *"
function arg to avoid a compiler warning caused by this patch.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003505.3855919-1-kafai@fb.com
David S. Miller