Daniel Borkmann says:
====================
bpf-next 2022-07-22
We've added 73 non-merge commits during the last 12 day(s) which contain
a total of 88 files changed, 3458 insertions(+), 860 deletions(-).
The main changes are:
1) Implement BPF trampoline for arm64 JIT, from Xu Kuohai.
2) Add ksyscall/kretsyscall section support to libbpf to simplify tracing kernel
syscalls through kprobe mechanism, from Andrii Nakryiko.
3) Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel
function, from Song Liu & Jiri Olsa.
4) Add new kfunc infrastructure for netfilter's CT e.g. to insert and change
entries, from Kumar Kartikeya Dwivedi & Lorenzo Bianconi.
5) Add a ksym BPF iterator to allow for more flexible and efficient interactions
with kernel symbols, from Alan Maguire.
6) Bug fixes in libbpf e.g. for uprobe binary path resolution, from Dan Carpenter.
7) Fix BPF subprog function names in stack traces, from Alexei Starovoitov.
8) libbpf support for writing custom perf event readers, from Jon Doron.
9) Switch to use SPDX tag for BPF helper man page, from Alejandro Colomar.
10) Fix xsk send-only sockets when in busy poll mode, from Maciej Fijalkowski.
11) Reparent BPF maps and their charging on memcg offlining, from Roman Gushchin.
12) Multiple follow-up fixes around BPF lsm cgroup infra, from Stanislav Fomichev.
13) Use bootstrap version of bpftool where possible to speed up builds, from Pu Lehui.
14) Cleanup BPF verifier's check_func_arg() handling, from Joanne Koong.
15) Make non-prealloced BPF map allocations low priority to play better with
memcg limits, from Yafang Shao.
16) Fix BPF test runner to reject zero-length data for skbs, from Zhengchao Shao.
17) Various smaller cleanups and improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (73 commits)
bpf: Simplify bpf_prog_pack_[size|mask]
bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
bpf, x64: Allow to use caller address from stack
ftrace: Allow IPMODIFY and DIRECT ops on the same function
ftrace: Add modify_ftrace_direct_multi_nolock
bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test
bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF
selftests/bpf: Fix test_verifier failed test in unprivileged mode
selftests/bpf: Add negative tests for new nf_conntrack kfuncs
selftests/bpf: Add tests for new nf_conntrack kfuncs
selftests/bpf: Add verifier tests for trusted kfunc args
net: netfilter: Add kfuncs to set and change CT status
net: netfilter: Add kfuncs to set and change CT timeout
net: netfilter: Add kfuncs to allocate and insert CT
net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
bpf: Add documentation for kfuncs
bpf: Add support for forcing kfunc args to be trusted
bpf: Switch to new kfunc flags infrastructure
tools/resolve_btfids: Add support for 8-byte BTF sets
bpf: Introduce 8-byte BTF set
...
====================
Link: https://lore.kernel.org/r/20220722221218.29943-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Simplify the logic that selects bpf_prog_pack_size, and always use
(PMD_SIZE * num_possible_nodes()). This is a good tradeoff, as most of
the performance benefit observed is from less direct map fragmentation [0].
Also, module_alloc(4MB) may not allocate 4MB aligned memory. Therefore,
we cannot use (ptr & bpf_prog_pack_mask) to find the correct address of
bpf_prog_pack. Fix this by checking the header address falls in the range
of pack->ptr and (pack->ptr + bpf_prog_pack_size).
[0] https://lore.kernel.org/bpf/20220707223546.4124919-1-song@kernel.org/
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20220713204950.3015201-1-song@kernel.org
IPMODIFY (livepatch) and DIRECT (bpf trampoline) ops are both important
users of ftrace. It is necessary to allow them work on the same function
at the same time.
First, DIRECT ops no longer specify IPMODIFY flag. Instead, DIRECT flag is
handled together with IPMODIFY flag in __ftrace_hash_update_ipmodify().
Then, a callback function, ops_func, is added to ftrace_ops. This is used
by ftrace core code to understand whether the DIRECT ops can share with an
IPMODIFY ops. To share with IPMODIFY ops, the DIRECT ops need to implement
the callback function and adjust the direct trampoline accordingly.
If DIRECT ops is attached before the IPMODIFY ops, ftrace core code calls
ENABLE_SHARE_IPMODIFY_PEER on the DIRECT ops before registering the
IPMODIFY ops.
If IPMODIFY ops is attached before the DIRECT ops, ftrace core code calls
ENABLE_SHARE_IPMODIFY_SELF in __ftrace_hash_update_ipmodify. Owner of the
DIRECT ops may return 0 if the DIRECT trampoline can share with IPMODIFY,
so error code otherwise. The error code is propagated to
register_ftrace_direct_multi so that onwer of the DIRECT trampoline can
handle it properly.
For more details, please refer to comment before enum ftrace_ops_cmd.
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/all/20220602193706.2607681-2-song@kernel.org/
Link: https://lore.kernel.org/all/20220718055449.3960512-1-song@kernel.org/
Link: https://lore.kernel.org/bpf/20220720002126.803253-3-song@kernel.org
Teach the verifier to detect a new KF_TRUSTED_ARGS kfunc flag, which
means each pointer argument must be trusted, which we define as a
pointer that is referenced (has non-zero ref_obj_id) and also needs to
have its offset unchanged, similar to how release functions expect their
argument. This allows a kfunc to receive pointer arguments unchanged
from the result of the acquire kfunc.
This is required to ensure that kfunc that operate on some object only
work on acquired pointers and not normal PTR_TO_BTF_ID with same type
which can be obtained by pointer walking. The restrictions applied to
release arguments also apply to trusted arguments. This implies that
strict type matching (not deducing type by recursively following members
at offset) and OBJ_RELEASE offset checks (ensuring they are zero) are
used for trusted pointer arguments.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Instead of populating multiple sets to indicate some attribute and then
researching the same BTF ID in them, prepare a single unified BTF set
which indicates whether a kfunc is allowed to be called, and also its
attributes if any at the same time. Now, only one call is needed to
perform the lookup for both kfunc availability and its attributes.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Sedat Dilek noticed that I had an extraneous semicolon at the end of a
line in the previous patch.
It's harmless, but unintentional, and while compilers just treat it as
an extra empty statement, for all I know some other tooling might warn
about it. So clean it up before other people notice too ;)
Fixes: 353f7988dd ("watchqueue: make sure to serialize 'wqueue->defunct' properly")
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Syzkaller found a problem similar to d1a6edecc1 ("bpf: Check
attach_func_proto more carefully in check_return_code") where
attach_func_proto might be NULL:
RIP: 0010:check_helper_call+0x3dcb/0x8d50 kernel/bpf/verifier.c:7330
do_check kernel/bpf/verifier.c:12302 [inline]
do_check_common+0x6e1e/0xb980 kernel/bpf/verifier.c:14610
do_check_main kernel/bpf/verifier.c:14673 [inline]
bpf_check+0x661e/0xc520 kernel/bpf/verifier.c:15243
bpf_prog_load+0x11ae/0x1f80 kernel/bpf/syscall.c:2620
With the following reproducer:
bpf$BPF_PROG_RAW_TRACEPOINT_LOAD(0x5, &(0x7f0000000780)={0xf, 0x4, &(0x7f0000000040)=@framed={{}, [@call={0x85, 0x0, 0x0, 0xbb}]}, &(0x7f0000000000)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, 0x2b, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0}, 0x80)
Let's do the same here, only check attach_func_proto for the prog types
where we are certain that attach_func_proto is defined.
Fixes: 69fd337a97 ("bpf: per-cgroup lsm flavor")
Reported-by: syzbot+0f8d989b1fba1addc5e0@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220720164729.147544-1-sdf@google.com
When the pipe is closed, we mark the associated watchqueue defunct by
calling watch_queue_clear(). However, while that is protected by the
watchqueue lock, new watchqueue entries aren't actually added under that
lock at all: they use the pipe->rd_wait.lock instead, and looking up
that pipe happens without any locking.
The watchqueue code uses the RCU read-side section to make sure that the
wqueue entry itself hasn't disappeared, but that does not protect the
pipe_info in any way.
So make sure to actually hold the wqueue lock when posting watch events,
properly serializing against the pipe being torn down.
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Syscall-side map_lookup_elem() and map_update_elem() used to use
kmalloc() to allocate temporary buffers of value_size, so
KMALLOC_MAX_SIZE limit on value_size made sense to prevent creation of
array map that won't be accessible through syscall interface.
But this limitation since has been lifted by relying on kvmalloc() in
syscall handling code. So remove KMALLOC_MAX_SIZE, which among other
things means that it's possible to have BPF global variable sections
(.bss, .data, .rodata) bigger than 8MB now. Keep the sanity check to
prevent trivial overflows like round_up(map->value_size, 8) and restrict
value size to <= INT_MAX (2GB).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220715053146.1291891-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF_MAP_TYPE_ARRAY is rounding value_size to closest multiple of 8 and
stores that as array->elem_size for various memory allocations and
accesses.
But the code tends to re-calculate round_up(map->value_size, 8) in
multiple places instead of using array->elem_size. Cleaning this up and
making sure we always use array->size to avoid duplication of this
(admittedly simple) logic for consistency.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220715053146.1291891-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If BPF array map is bigger than 4GB, element pointer calculation can
overflow because both index and elem_size are u32. Fix this everywhere
by forcing 64-bit multiplication. Extract this formula into separate
small helper and use it consistently in various places.
Speculative-preventing formula utilizing index_mask trick is left as is,
but explicit u64 casts are added in both places.
Fixes: c85d69135a ("bpf: move memory size checks to bpf_map_charge_init()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220715053146.1291891-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull perf fix from Borislav Petkov:
- A single data race fix on the perf event cleanup path to avoid
endless loops due to insufficient locking
* tag 'perf_urgent_for_v5.19_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
Pull printk fix from Petr Mladek:
- Make pr_flush() fast when consoles are suspended.
* tag 'printk-for-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: do not wait for consoles when suspended
When checking with sparse, btf_show_type_value() is causing a
warning about checking integer vs NULL when the macro is passed
a pointer, due to the 'value != 0' check. Stop sparse complaining
about any type-casting by adding a cast to the typeof(value).
This fixes the following sparse warnings:
kernel/bpf/btf.c:2579:17: warning: Using plain integer as NULL pointer
kernel/bpf/btf.c:2581:17: warning: Using plain integer as NULL pointer
kernel/bpf/btf.c:3407:17: warning: Using plain integer as NULL pointer
kernel/bpf/btf.c:3758:9: warning: Using plain integer as NULL pointer
Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220714100322.260467-1-ben.dooks@sifive.com
Pyll sysctl fix from Luis Chamberlain:
"Only one fix for sysctl"
* tag 'sysctl-fixes-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
mm: sysctl: fix missing numa_stat when !CONFIG_HUGETLB_PAGE
The console_stop() and console_start() functions call pr_flush().
When suspending, these functions are called by the serial subsystem
while the serial port is suspended. In this scenario, if there are
any pending messages, a call to pr_flush() will always result in a
timeout because the serial port cannot make forward progress. This
causes longer suspend and resume times.
Add a check in pr_flush() so that it will immediately timeout if
the consoles are suspended.
Fixes: 3b604ca812 ("printk: add pr_flush()")
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220715061042.373640-2-john.ogness@linutronix.de
The commit 7337224fc1 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior")
accidently made bpf_prog_ksym_set_name() conservative for bpf subprograms.
Fixed it so instead of "bpf_prog_tag_F" the stack traces print "bpf_prog_tag_full_subprog_name".
Fixes: 7337224fc1 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220714211637.17150-1-alexei.starovoitov@gmail.com
"numa_stat" should not be included in the scope of CONFIG_HUGETLB_PAGE, if
CONFIG_HUGETLB_PAGE is not configured even if CONFIG_NUMA is configured,
"numa_stat" is missed form /proc. Move it out of CONFIG_HUGETLB_PAGE to
fix it.
Fixes: 4518085e12 ("mm, sysctl: make NUMA stats configurable")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter, bpf and wireless.
Still no major regressions, the release continues to be calm. An
uptick of fixes this time around due to trivial data race fixes and
patches flowing down from subtrees.
There has been a few driver fixes (particularly a few fixes for false
positives due to 66e4c8d950 which went into -next in May!) that make
me worry the wide testing is not exactly fully through.
So "calm" but not "let's just cut the final ASAP" vibes over here.
Current release - regressions:
- wifi: rtw88: fix write to const table of channel parameters
Current release - new code bugs:
- mac80211: add gfp_t arg to ieeee80211_obss_color_collision_notify
- mlx5:
- TC, allow offload from uplink to other PF's VF
- Lag, decouple FDB selection and shared FDB
- Lag, correct get the port select mode str
- bnxt_en: fix and simplify XDP transmit path
- r8152: fix accessing unset transport header
Previous releases - regressions:
- conntrack: fix crash due to confirmed bit load reordering (after
atomic -> refcount conversion)
- stmmac: dwc-qos: disable split header for Tegra194
Previous releases - always broken:
- mlx5e: ring the TX doorbell on DMA errors
- bpf: make sure mac_header was set before using it
- mac80211: do not wake queues on a vif that is being stopped
- mac80211: fix queue selection for mesh/OCB interfaces
- ip: fix dflt addr selection for connected nexthop
- seg6: fix skb checksums for SRH encapsulation/insertion
- xdp: fix spurious packet loss in generic XDP TX path
- bunch of sysctl data race fixes
- nf_log: incorrect offset to network header
Misc:
- bpf: add flags arg to bpf_dynptr_read and bpf_dynptr_write APIs"
* tag 'net-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (87 commits)
nfp: flower: configure tunnel neighbour on cmsg rx
net/tls: Check for errors in tls_device_init
MAINTAINERS: Add an additional maintainer to the AMD XGBE driver
xen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue
selftests/net: test nexthop without gw
ip: fix dflt addr selection for connected nexthop
net: atlantic: remove aq_nic_deinit() when resume
net: atlantic: remove deep parameter on suspend/resume functions
sfc: fix kernel panic when creating VF
seg6: bpf: fix skb checksum in bpf_push_seg6_encap()
seg6: fix skb checksum in SRv6 End.B6 and End.B6.Encaps behaviors
seg6: fix skb checksum evaluation in SRH encapsulation/insertion
sfc: fix use after free when disabling sriov
net: sunhme: output link status with a single print.
r8152: fix accessing unset transport header
net: stmmac: fix leaks in probe
net: ftgmac100: Hold reference returned by of_get_child_by_name()
nexthop: Fix data-races around nexthop_compat_mode.
ipv4: Fix data-races around sysctl_ip_dynaddr.
tcp: Fix a data-race around sysctl_tcp_ecn_fallback.
...
Pull integrity fixes from Mimi Zohar:
"Here are a number of fixes for recently found bugs.
Only 'ima: fix violation measurement list record' was introduced in
the current release. The rest address existing bugs"
* tag 'integrity-v5.19-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: Fix potential memory leak in ima_init_crypto()
ima: force signature verification when CONFIG_KEXEC_SIG is configured
ima: Fix a potential integer overflow in ima_appraise_measurement
ima: fix violation measurement list record
Revert "evm: Fix memleak in init_desc"
Pull cgroup fix from Tejun Heo:
"Fix an old and subtle bug in the migration path.
css_sets are used to track tasks and migrations are tasks moving from
a group of css_sets to another group of css_sets. The migration path
pins all source and destination css_sets in the prep stage.
Unfortunately, it was overloading the same list_head entry to track
sources and destinations, which got confused for migrations which are
partially identity leading to use-after-frees.
Fixed by using dedicated list_heads for tracking sources and
destinations"
* tag 'cgroup-for-5.19-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Use separate src/dst nodes when preloading css_sets for migration
Currently, an unsigned kernel could be kexec'ed when IMA arch specific
policy is configured unless lockdown is enabled. Enforce kernel
signature verification check in the kexec_file_load syscall when IMA
arch specific policy is configured.
Fixes: 99d5cadfde ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE")
Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
A sysctl variable is accessed concurrently, and there is always a chance
of data-race. So, all readers and writers need some basic protection to
avoid load/store-tearing.
This patch changes proc_dointvec_ms_jiffies() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side. For now,
proc_dointvec_ms_jiffies() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A sysctl variable is accessed concurrently, and there is always a chance
of data-race. So, all readers and writers need some basic protection to
avoid load/store-tearing.
This patch changes proc_dou8vec_minmax() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side. For now,
proc_dou8vec_minmax() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.
Fixes: cb94441306 ("sysctl: add proc_dou8vec_minmax()")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Yang Jihing reported a race between perf_event_set_output() and
perf_mmap_close():
CPU1 CPU2
perf_mmap_close(e2)
if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0
detach_rest = true
ioctl(e1, IOC_SET_OUTPUT, e2)
perf_event_set_output(e1, e2)
...
list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry)
ring_buffer_attach(e, NULL);
// e1 isn't yet added and
// therefore not detached
ring_buffer_attach(e1, e2->rb)
list_add_rcu(&e1->rb_entry,
&e2->rb->event_list)
After this; e1 is attached to an unmapped rb and a subsequent
perf_mmap() will loop forever more:
again:
mutex_lock(&e->mmap_mutex);
if (event->rb) {
...
if (!atomic_inc_not_zero(&e->rb->mmap_count)) {
...
mutex_unlock(&e->mmap_mutex);
goto again;
}
}
The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach
in perf_event_set_output() holds e1->mmap_mutex. As such there is no
serialization to avoid this race.
Change perf_event_set_output() to take both e1->mmap_mutex and
e2->mmap_mutex to alleviate that problem. Additionally, have the loop
in perf_mmap() detach the rb directly, this avoids having to wait for
the concurrent perf_mmap_close() to get around to doing it to make
progress.
Fixes: 9bb5d40cd9 ("perf: Fix mmap() accounting hole")
Reported-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lkml.kernel.org/r/YsQ3jm2GR38SW7uD@worktop.programming.kicks-ass.net
GFP_ATOMIC doesn't cooperate well with memcg pressure so far, especially
if we allocate too much GFP_ATOMIC memory. For example, when we set the
memcg limit to limit a non-preallocated bpf memory, the GFP_ATOMIC can
easily break the memcg limit by force charge. So it is very dangerous to
use GFP_ATOMIC in non-preallocated case. One way to make it safe is to
remove __GFP_HIGH from GFP_ATOMIC, IOW, use (__GFP_ATOMIC |
__GFP_KSWAPD_RECLAIM) instead, then it will be limited if we allocate
too much memory. There's a plan to completely remove __GFP_ATOMIC in the
mm side[1], so let's use GFP_NOWAIT instead.
We introduced BPF_F_NO_PREALLOC is because full map pre-allocation is
too memory expensive for some cases. That means removing __GFP_HIGH
doesn't break the rule of BPF_F_NO_PREALLOC, but has the same goal with
it-avoiding issues caused by too much memory. So let's remove it.
This fix can also apply to other run-time allocations, for example, the
allocation in lpm trie, local storage and devmap. So let fix it
consistently over the bpf code
It also fixes a typo in the comment.
[1]. https://lore.kernel.org/linux-mm/163712397076.13692.4727608274002939094@noble.neil.brown.name/
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Link: https://lore.kernel.org/r/20220709154457.57379-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
syzbot reported a few issues with bpf_prog_pack [1], [2]. This only happens
with multiple subprogs. In jit_subprogs(), we first call bpf_int_jit_compile()
on each sub program. And then, we call it on each sub program again. jit_data
is not freed in the first call of bpf_int_jit_compile(). Similarly we don't
call bpf_jit_binary_pack_finalize() in the first call of bpf_int_jit_compile().
If bpf_int_jit_compile() failed for one sub program, we will call
bpf_jit_binary_pack_finalize() for this sub program. However, we don't have a
chance to call it for other sub programs. Then we will hit "goto out_free" in
jit_subprogs(), and call bpf_jit_free on some subprograms that haven't got
bpf_jit_binary_pack_finalize() yet.
At this point, bpf_jit_binary_pack_free() is called and the whole 2MB page is
freed erroneously.
Fix this with a custom bpf_jit_free() for x86_64, which calls
bpf_jit_binary_pack_finalize() if necessary. Also, with custom
bpf_jit_free(), bpf_prog_aux->use_bpf_prog_pack is not needed any more,
remove it.
Fixes: 1022a5498f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc")
[1] https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f
[2] https://syzkaller.appspot.com/bug?extid=87f65c75f4a72db05445
Reported-by: syzbot+2f649ec6d2eea1495a8f@syzkaller.appspotmail.com
Reported-by: syzbot+87f65c75f4a72db05445@syzkaller.appspotmail.com
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20220706002612.4013790-1-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull tracing fixes from Steven Rostedt:
"Fixes and minor clean ups for tracing:
- Fix memory leak by reverting what was thought to be a double free.
A static tool had gave a false positive that a double free was
possible in the error path, but it was actually a different
location that confused the static analyzer (and those of us that
reviewed it).
- Move use of static buffers by ftrace_dump() to a location that can
be used by kgdb's ftdump(), as it needs it for the same reasons.
- Clarify in the Kconfig description that function tracing has
negligible impact on x86, but may have a bit bigger impact on other
architectures.
- Remove unnecessary extra semicolon in trace event.
- Make a local variable static that is used in the fprobes sample
- Use KSYM_NAME_LEN for length of function in kprobe sample and get
rid of unneeded macro for the same purpose"
* tag 'trace-v5.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
samples: Use KSYM_NAME_LEN for kprobes
fprobe/samples: Make sample_probe static
blk-iocost: tracing: atomic64_read(&ioc->vtime_rate) is assigned an extra semicolon
ftrace: Be more specific about arch impact when function tracer is enabled
tracing: Fix sleeping while atomic in kdb ftdump
tracing/histograms: Fix memory leak problem
The memory consumed by a bpf map is always accounted to the memory
cgroup of the process which created the map. The map can outlive
the memory cgroup if it's used by processes in other cgroups or
is pinned on bpffs. In this case the map pins the original cgroup
in the dying state.
For other types of objects (slab objects, non-slab kernel allocations,
percpu objects and recently LRU pages) there is a reparenting process
implemented: on cgroup offlining charged objects are getting
reassigned to the parent cgroup. Because all charges and statistics
are fully recursive it's a fairly cheap operation.
For efficiency and consistency with other types of objects, let's do
the same for bpf maps. Fortunately thanks to the objcg API, the
required changes are minimal.
Please, note that individual allocations (slabs, percpu and large
kmallocs) already have the reparenting mechanism. This commit adds
it to the saved map->memcg pointer by replacing it to map->objcg.
Because dying cgroups are not visible for a user and all charges are
recursive, this commit doesn't bring any behavior changes for a user.
v2:
added a missing const qualifier
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Link: https://lore.kernel.org/r/20220711162827.184743-1-roman.gushchin@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
It was brought up that on ARMv7, that because the FUNCTION_TRACER does not
use nops to keep function tracing disabled because of the use of a link
register, it does have some performance impact.
The start of functions when -pg is used to compile the kernel is:
push {lr}
bl 8010e7c0 <__gnu_mcount_nc>
When function tracing is tuned off, it becomes:
push {lr}
add sp, sp, #4
Which just puts the stack back to its normal location. But these two
instructions at the start of every function does incur some overhead.
Be more honest in the Kconfig FUNCTION_TRACER description and specify that
the overhead being in the noise was x86 specific, but other architectures
may vary.
Link: https://lore.kernel.org/all/20220705105416.GE5208@pengutronix.de/
Link: https://lkml.kernel.org/r/20220706161231.085a83da@gandalf.local.home
Reported-by: Sascha Hauer <sha@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
If you drop into kdb and type "ftdump" you'll get a sleeping while
atomic warning from memory allocation in trace_find_next_entry().
This appears to have been caused by commit ff895103a8 ("tracing:
Save off entry when peeking at next entry"), which added the
allocation in that path. The problematic commit was already fixed by
commit 8e99cf91b9 ("tracing: Do not allocate buffer in
trace_find_next_entry() in atomic") but that fix missed the kdb case.
The fix here is easy: just move the assignment of the static buffer to
the place where it should have been to begin with:
trace_init_global_iter(). That function is called in two places, once
is right before the assignment of the static buffer added by the
previous fix and once is in kdb.
Note that it appears that there's a second static buffer that we need
to assign that was added in commit efbbdaa22b ("tracing: Show real
address for trace event arguments"), so we'll move that too.
Link: https://lkml.kernel.org/r/20220708170919.1.I75844e5038d9425add2ad853a608cb44bb39df40@changeid
Fixes: ff895103a8 ("tracing: Save off entry when peeking at next entry")
Fixes: efbbdaa22b ("tracing: Show real address for trace event arguments")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This reverts commit 46bbe5c671.
As commit 46bbe5c671 ("tracing: fix double free") said, the
"double free" problem reported by clang static analyzer is:
> In parse_var_defs() if there is a problem allocating
> var_defs.expr, the earlier var_defs.name is freed.
> This free is duplicated by free_var_defs() which frees
> the rest of the list.
However, if there is a problem allocating N-th var_defs.expr:
+ in parse_var_defs(), the freed 'earlier var_defs.name' is
actually the N-th var_defs.name;
+ then in free_var_defs(), the names from 0th to (N-1)-th are freed;
IF ALLOCATING PROBLEM HAPPENED HERE!!! -+
\
|
0th 1th (N-1)-th N-th V
+-------------+-------------+-----+-------------+-----------
var_defs: | name | expr | name | expr | ... | name | expr | name | ///
+-------------+-------------+-----+-------------+-----------
These two frees don't act on same name, so there was no "double free"
problem before. Conversely, after that commit, we get a "memory leak"
problem because the above "N-th var_defs.name" is not freed.
If enable CONFIG_DEBUG_KMEMLEAK and inject a fault at where the N-th
var_defs.expr allocated, then execute on shell like:
$ echo 'hist:key=call_site:val=$v1,$v2:v1=bytes_req,v2=bytes_alloc' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
Then kmemleak reports:
unreferenced object 0xffff8fb100ef3518 (size 8):
comm "bash", pid 196, jiffies 4295681690 (age 28.538s)
hex dump (first 8 bytes):
76 31 00 00 b1 8f ff ff v1......
backtrace:
[<0000000038fe4895>] kstrdup+0x2d/0x60
[<00000000c99c049a>] event_hist_trigger_parse+0x206f/0x20e0
[<00000000ae70d2cc>] trigger_process_regex+0xc0/0x110
[<0000000066737a4c>] event_trigger_write+0x75/0xd0
[<000000007341e40c>] vfs_write+0xbb/0x2a0
[<0000000087fde4c2>] ksys_write+0x59/0xd0
[<00000000581e9cdf>] do_syscall_64+0x3a/0x80
[<00000000cf3b065c>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Link: https://lkml.kernel.org/r/20220711014731.69520-1-zhengyejian1@huawei.com
Cc: stable@vger.kernel.org
Fixes: 46bbe5c671 ("tracing: fix double free")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull module fixes from Luis Chamberlain:
"Although most of the move of code in in v5.19-rc1 should have not
introduced a regression patch review on one of the file changes
captured a checkpatch warning which advised to use strscpy() and it
caused a buffer overflow when an incorrect length is passed.
Another change which checkpatch complained about was an odd RCU usage,
but that was properly addressed in a separate patch to the move by
Aaron. That caused a regression with PREEMPT_RT=y due to an unbounded
latency.
This series fixes both and adjusts documentation which we forgot to do
for the move"
* tag 'modules-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
module: kallsyms: Ensure preemption in add_kallsyms() with PREEMPT_RT
doc: module: update file references
module: Fix "warning: variable 'exit' set but not used"
module: Fix selfAssignment cppcheck warning
modules: Fix corruption of /proc/kallsyms
Before generating bpf trampoline, x86 calls is_valid_bpf_tramp_flags()
to check the input flags. This check is architecture independent.
So, to be consistent with x86, arm64 should also do this check
before generating bpf trampoline.
However, the BPF_TRAMP_F_XXX flags are not used by user code and the
flags argument is almost constant at compile time, so this run time
check is a bit redundant.
Remove is_valid_bpf_tramp_flags() and add some comments to the usage of
BPF_TRAMP_F_XXX flags, as suggested by Alexei.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220711150823.2128542-2-xukuohai@huawei.com
The commit 08126db5ff ("module: kallsyms: Fix suspicious rcu usage")
under PREEMPT_RT=y, disabling preemption introduced an unbounded
latency since the loop is not fixed. This change caused a regression
since previously preemption was not disabled and we would dereference
RCU-protected pointers explicitly. That being said, these pointers
cannot change.
Before kallsyms-specific data is prepared/or set-up, we ensure that
the unformed module is known to be unique i.e. does not already exist
(see load_module()). Therefore, we can fix this by using the common and
more appropriate RCU flavour as this section of code can be safely
preempted.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Fixes: 08126db5ff ("module: kallsyms: Fix suspicious rcu usage")
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
As Chris explains, the comment above exit_itimers() is not correct,
we can race with proc_timers_seq_ops. Change exit_itimers() to clear
signal->posix_timers with ->siglock held.
Cc: <stable@vger.kernel.org>
Reported-by: chris@accessvector.net
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-07-09
We've added 94 non-merge commits during the last 19 day(s) which contain
a total of 125 files changed, 5141 insertions(+), 6701 deletions(-).
The main changes are:
1) Add new way for performing BTF type queries to BPF, from Daniel Müller.
2) Add inlining of calls to bpf_loop() helper when its function callback is
statically known, from Eduard Zingerman.
3) Implement BPF TCP CC framework usability improvements, from Jörn-Thorben Hinz.
4) Add LSM flavor for attaching per-cgroup BPF programs to existing LSM
hooks, from Stanislav Fomichev.
5) Remove all deprecated libbpf APIs in prep for 1.0 release, from Andrii Nakryiko.
6) Add benchmarks around local_storage to BPF selftests, from Dave Marchevsky.
7) AF_XDP sample removal (given move to libxdp) and various improvements around AF_XDP
selftests, from Magnus Karlsson & Maciej Fijalkowski.
8) Add bpftool improvements for memcg probing and bash completion, from Quentin Monnet.
9) Add arm64 JIT support for BPF-2-BPF coupled with tail calls, from Jakub Sitnicki.
10) Sockmap optimizations around throughput of UDP transmissions which have been
improved by 61%, from Cong Wang.
11) Rework perf's BPF prologue code to remove deprecated functions, from Jiri Olsa.
12) Fix sockmap teardown path to avoid sleepable sk_psock_stop, from John Fastabend.
13) Fix libbpf's cleanup around legacy kprobe/uprobe on error case, from Chuang Wang.
14) Fix libbpf's bpf_helpers.h to work with gcc for the case of its sec/pragma
macro, from James Hilliard.
15) Fix libbpf's pt_regs macros for riscv to use a0 for RC register, from Yixun Lan.
16) Fix bpftool to show the name of type BPF_OBJ_LINK, from Yafang Shao.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (94 commits)
selftests/bpf: Fix xdp_synproxy build failure if CONFIG_NF_CONNTRACK=m/n
bpf: Correctly propagate errors up from bpf_core_composites_match
libbpf: Disable SEC pragma macro on GCC
bpf: Check attach_func_proto more carefully in check_return_code
selftests/bpf: Add test involving restrict type qualifier
bpftool: Add support for KIND_RESTRICT to gen min_core_btf command
MAINTAINERS: Add entry for AF_XDP selftests files
selftests, xsk: Rename AF_XDP testing app
bpf, docs: Remove deprecated xsk libbpf APIs description
selftests/bpf: Add benchmark for local_storage RCU Tasks Trace usage
libbpf, riscv: Use a0 for RC register
libbpf: Remove unnecessary usdt_rel_ip assignments
selftests/bpf: Fix few more compiler warnings
selftests/bpf: Fix bogus uninitialized variable warning
bpftool: Remove zlib feature test from Makefile
libbpf: Cleanup the legacy uprobe_event on failed add/attach_event()
libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy()
libbpf: Cleanup the legacy kprobe_event on failed add/attach_event()
selftests/bpf: Add type match test against kernel's task_struct
selftests/bpf: Add nested type to type based tests
...
====================
Link: https://lore.kernel.org/r/20220708233145.32365-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
CI reported the following splat while running the strace testsuite:
WARNING: CPU: 1 PID: 3570031 at kernel/ptrace.c:272 ptrace_check_attach+0x12e/0x178
CPU: 1 PID: 3570031 Comm: strace Tainted: G OE 5.19.0-20220624.rc3.git0.ee819a77d4e7.300.fc36.s390x #1
Hardware name: IBM 3906 M04 704 (z/VM 7.1.0)
Call Trace:
[<00000000ab4b645a>] ptrace_check_attach+0x132/0x178
([<00000000ab4b6450>] ptrace_check_attach+0x128/0x178)
[<00000000ab4b6cde>] __s390x_sys_ptrace+0x86/0x160
[<00000000ac03fcec>] __do_syscall+0x1d4/0x200
[<00000000ac04e312>] system_call+0x82/0xb0
Last Breaking-Event-Address:
[<00000000ab4ea3c8>] wait_task_inactive+0x98/0x190
This is because JOBCTL_TRACED is set, but the task is not in TASK_TRACED
state. Caused by ptrace_unfreeze_traced() which does:
task->jobctl &= ~TASK_TRACED
but it should be:
task->jobctl &= ~JOBCTL_TRACED
Fixes: 31cae1eaae ("sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Borkmann says:
====================
bpf 2022-07-08
We've added 3 non-merge commits during the last 2 day(s) which contain
a total of 7 files changed, 40 insertions(+), 24 deletions(-).
The main changes are:
1) Fix cBPF splat triggered by skb not having a mac header, from Eric Dumazet.
2) Fix spurious packet loss in generic XDP when pushing packets out (note
that native XDP is not affected by the issue), from Johan Almbladh.
3) Fix bpf_dynptr_{read,write}() helper signatures with flag argument before
its set in stone as UAPI, from Joanne Koong.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Add flags arg to bpf_dynptr_read and bpf_dynptr_write APIs
bpf: Make sure mac_header was set before using it
xdp: Fix spurious packet loss in generic XDP TX path
====================
Link: https://lore.kernel.org/r/20220708213418.19626-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
