Commit Graph

37277 Commits

Author SHA1 Message Date
Eric Dumazet
d979617aa8 bpf: Fixes possible race in update_prog_stats() for 32bit arches
It seems update_prog_stats() suffers from same issue fixed
in the prior patch:

As it can run while interrupts are enabled, it could
be re-entered and the u64_stats syncp could be mangled.

Fixes: fec56f5890 ("bpf: Introduce BPF trampoline")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-3-eric.dumazet@gmail.com
2021-10-27 11:13:52 -07:00
Yonghong Song
bd16dee66a bpf: Add BTF_KIND_DECL_TAG typedef support
The llvm patches ([1], [2]) added support to attach btf_decl_tag
attributes to typedef declarations. This patch added
support in kernel.

  [1] https://reviews.llvm.org/D110127
  [2] https://reviews.llvm.org/D112259

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211021195628.4018847-1-yhs@fb.com
2021-10-22 17:04:43 -07:00
Dave Marchevsky
aba64c7da9 bpf: Add verified_insns to bpf_prog_info and fdinfo
This stat is currently printed in the verifier log and not stored
anywhere. To ease consumption of this data, add a field to bpf_prog_aux
so it can be exposed via BPF_OBJ_GET_INFO_BY_FD and fdinfo.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211020074818.1017682-2-davemarchevsky@fb.com
2021-10-21 15:51:47 -07:00
Hengqi Chen
9eeb3aa33a bpf: Add bpf_skc_to_unix_sock() helper
The helper is used in tracing programs to cast a socket
pointer to a unix_sock pointer.
The return value could be NULL if the casting is illegal.

Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021134752.1223426-2-hengqi.chen@gmail.com
2021-10-21 15:11:06 -07:00
Quentin Monnet
5f52d47c5f bpf/preload: Clean up .gitignore and "clean-files" target
kernel/bpf/preload/Makefile was recently updated to have it install
libbpf's headers locally instead of pulling them from tools/lib/bpf. But
two items still need to be addressed.

First, the local .gitignore file was not adjusted to ignore the files
generated in the new kernel/bpf/preload/libbpf output directory.

Second, the "clean-files" target is now incorrect. The old artefacts
names were not removed from the target, while the new ones were added
incorrectly. This is because "clean-files" expects names relative to
$(obj), but we passed the absolute path instead. This results in the
output and header-destination directories for libbpf (and their
contents) not being removed from kernel/bpf/preload on "make clean" from
the root of the repository.

This commit fixes both issues. Note that $(userprogs) needs not be added
to "clean-files", because the cleaning infrastructure already accounts
for it.

Cleaning the files properly also prevents make from printing the
following message, for builds coming after a "make clean":
"make[4]: Nothing to be done for 'install_headers'."

v2: Simplify the "clean-files" target.

Fixes: bf60791741 ("bpf: preload: Install libbpf headers when building")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211020094647.15564-1-quentin@isovalent.com
2021-10-20 10:39:04 -07:00
Kumar Kartikeya Dwivedi
588cd7ef53 bpf: Silence Coverity warning for find_kfunc_desc_btf
The helper function returns a pointer that in the failure case encodes
an error in the struct btf pointer. The current code lead to Coverity
warning about the use of the invalid pointer:

 *** CID 1507963:  Memory - illegal accesses  (USE_AFTER_FREE)
 /kernel/bpf/verifier.c: 1788 in find_kfunc_desc_btf()
 1782                          return ERR_PTR(-EINVAL);
 1783                  }
 1784
 1785                  kfunc_btf = __find_kfunc_desc_btf(env, offset, btf_modp);
 1786                  if (IS_ERR_OR_NULL(kfunc_btf)) {
 1787                          verbose(env, "cannot find module BTF for func_id %u\n", func_id);
 >>>      CID 1507963:  Memory - illegal accesses  (USE_AFTER_FREE)
 >>>      Using freed pointer "kfunc_btf".
 1788                          return kfunc_btf ?: ERR_PTR(-ENOENT);
 1789                  }
 1790                  return kfunc_btf;
 1791          }
 1792          return btf_vmlinux ?: ERR_PTR(-ENOENT);
 1793     }

Daniel suggested the use of ERR_CAST so that the intended use is clear
to Coverity, but on closer look it seems that we never return NULL from
the helper. Andrii noted that since __find_kfunc_desc_btf already logs
errors for all cases except btf_get_by_fd, it is much easier to add
logging for that and remove the IS_ERR check altogether, returning
directly from it.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211009040900.803436-1-memxor@gmail.com
2021-10-19 16:55:50 -07:00
Yonghong Song
223f903e9c bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG
Patch set [1] introduced BTF_KIND_TAG to allow tagging
declarations for struct/union, struct/union field, var, func
and func arguments and these tags will be encoded into
dwarf. They are also encoded to btf by llvm for the bpf target.

After BTF_KIND_TAG is introduced, we intended to use it
for kernel __user attributes. But kernel __user is actually
a type attribute. Upstream and internal discussion showed
it is not a good idea to mix declaration attribute and
type attribute. So we proposed to introduce btf_type_tag
as a type attribute and existing btf_tag renamed to
btf_decl_tag ([2]).

This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some
other declarations with *_tag to *_decl_tag to make it clear
the tag is for declaration. In the future, BTF_KIND_TYPE_TAG
might be introduced per [3].

 [1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/
 [2] https://reviews.llvm.org/D111588
 [3] https://reviews.llvm.org/D111199

Fixes: b5ea834dde ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd1036 ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec0 ("bpftool: Add support for BTF_KIND_TAG")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
2021-10-18 18:35:36 -07:00
Quentin Monnet
d7db0a4e8d bpftool: Add install-bin target to install binary only
With "make install", bpftool installs its binary and its bash completion
file. Usually, this is what we want. But a few components in the kernel
repository (namely, BPF iterators and selftests) also install bpftool
locally before using it. In such a case, bash completion is not
necessary and is just a useless build artifact.

Let's add an "install-bin" target to bpftool, to offer a way to install
the binary only.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-13-quentin@isovalent.com
2021-10-08 12:02:40 -07:00
Quentin Monnet
7bf731dcc6 bpf: iterators: Install libbpf headers when building
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that bpf/preload/iterators/Makefile
installs the headers properly when building.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-8-quentin@isovalent.com
2021-10-08 11:58:54 -07:00
Quentin Monnet
bf60791741 bpf: preload: Install libbpf headers when building
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that bpf/preload/Makefile installs the
headers properly when building.

Note that we declare an additional dependency for iterators/iterators.o:
having $(LIBBPF_A) as a dependency to "$(obj)/bpf_preload_umd" is not
sufficient, as it makes it required only at the linking step. But we
need libbpf to be compiled, and in particular its headers to be
exported, before we attempt to compile iterators.o. The issue would not
occur before this commit, because libbpf's headers were not exported and
were always available under tools/lib/bpf.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-7-quentin@isovalent.com
2021-10-08 11:56:42 -07:00
Andrey Ignatov
0640c77c46 bpf: Avoid retpoline for bpf_for_each_map_elem
Similarly to 09772d92cd ("bpf: avoid retpoline for
lookup/update/delete calls on maps") and 84430d4232 ("bpf, verifier:
avoid retpoline for map push/pop/peek operation") avoid indirect call
while calling bpf_for_each_map_elem.

Before (a program fragment):

  ; if (rules_map) {
   142: (15) if r4 == 0x0 goto pc+8
   143: (bf) r3 = r10
  ; bpf_for_each_map_elem(rules_map, process_each_rule, &ctx, 0);
   144: (07) r3 += -24
   145: (bf) r1 = r4
   146: (18) r2 = subprog[+5]
   148: (b7) r4 = 0
   149: (85) call bpf_for_each_map_elem#143680  <-- indirect call via
                                                    helper

After (same program fragment):

   ; if (rules_map) {
    142: (15) if r4 == 0x0 goto pc+8
    143: (bf) r3 = r10
   ; bpf_for_each_map_elem(rules_map, process_each_rule, &ctx, 0);
    144: (07) r3 += -24
    145: (bf) r1 = r4
    146: (18) r2 = subprog[+5]
    148: (b7) r4 = 0
    149: (85) call bpf_for_each_array_elem#170336  <-- direct call

On a benchmark that calls bpf_for_each_map_elem() once and does many
other things (mostly checking fields in skb) with CONFIG_RETPOLINE=y it
makes program faster.

Before:

  ============================================================================
  Benchmark.cpp                                              time/iter iters/s
  ============================================================================
  IngressMatchByRemoteEndpoint                                80.78ns 12.38M
  IngressMatchByRemoteIP                                      80.66ns 12.40M
  IngressMatchByRemotePort                                    80.87ns 12.37M

After:

  ============================================================================
  Benchmark.cpp                                              time/iter iters/s
  ============================================================================
  IngressMatchByRemoteEndpoint                                73.49ns 13.61M
  IngressMatchByRemoteIP                                      71.48ns 13.99M
  IngressMatchByRemotePort                                    70.39ns 14.21M

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211006001838.75607-1-rdna@fb.com
2021-10-05 19:22:33 -07:00
Kumar Kartikeya Dwivedi
c48e51c8b0 bpf: selftests: Add selftests for module kfunc support
This adds selftests that tests the success and failure path for modules
kfuncs (in presence of invalid kfunc calls) for both libbpf and
gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can
add module BTF ID set from bpf_testmod.

This also introduces  a couple of test cases to verifier selftests for
validating whether we get an error or not depending on if invalid kfunc
call remains after elimination of unreachable instructions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-10-memxor@gmail.com
2021-10-05 17:07:42 -07:00
Kumar Kartikeya Dwivedi
0e32dfc80b bpf: Enable TCP congestion control kfunc from modules
This commit moves BTF ID lookup into the newly added registration
helper, in a way that the bbr, cubic, and dctcp implementation set up
their sets in the bpf_tcp_ca kfunc_btf_set list, while the ones not
dependent on modules are looked up from the wrapper function.

This lifts the restriction for them to be compiled as built in objects,
and can be loaded as modules if required. Also modify Makefile.modfinal
to call resolve_btfids for each module.

Note that since kernel kfunc_ids never overlap with module kfunc_ids, we
only match the owner for module btf id sets.

See following commits for background on use of:

 CONFIG_X86 ifdef:
 569c484f99 (bpf: Limit static tcp-cc functions in the .BTF_ids list to x86)

 CONFIG_DYNAMIC_FTRACE ifdef:
 7aae231ac9 (bpf: tcp: Limit calling some tcp cc functions to CONFIG_DYNAMIC_FTRACE)

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-6-memxor@gmail.com
2021-10-05 17:07:41 -07:00
Kumar Kartikeya Dwivedi
14f267d95f bpf: btf: Introduce helpers for dynamic BTF set registration
This adds helpers for registering btf_id_set from modules and the
bpf_check_mod_kfunc_call callback that can be used to look them up.

With in kernel sets, the way this is supposed to work is, in kernel
callback looks up within the in-kernel kfunc whitelist, and then defers
to the dynamic BTF set lookup if it doesn't find the BTF id. If there is
no in-kernel BTF id set, this callback can be used directly.

Also fix includes for btf.h and bpfptr.h so that they can included in
isolation. This is in preparation for their usage in tcp_bbr, tcp_cubic
and tcp_dctcp modules in the next patch.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-4-memxor@gmail.com
2021-10-05 17:07:41 -07:00
Kumar Kartikeya Dwivedi
a5d8272752 bpf: Be conservative while processing invalid kfunc calls
This patch also modifies the BPF verifier to only return error for
invalid kfunc calls specially marked by userspace (with insn->imm == 0,
insn->off == 0) after the verifier has eliminated dead instructions.
This can be handled in the fixup stage, and skip processing during add
and check stages.

If such an invalid call is dropped, the fixup stage will not encounter
insn->imm as 0, otherwise it bails out and returns an error.

This will be exposed as weak ksym support in libbpf in later patches.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-3-memxor@gmail.com
2021-10-05 17:07:41 -07:00
Kumar Kartikeya Dwivedi
2357672c54 bpf: Introduce BPF support for kernel module function calls
This change adds support on the kernel side to allow for BPF programs to
call kernel module functions. Userspace will prepare an array of module
BTF fds that is passed in during BPF_PROG_LOAD using fd_array parameter.
In the kernel, the module BTFs are placed in the auxilliary struct for
bpf_prog, and loaded as needed.

The verifier then uses insn->off to index into the fd_array. insn->off
0 is reserved for vmlinux BTF (for backwards compat), so userspace must
use an fd_array index > 0 for module kfunc support. kfunc_btf_tab is
sorted based on offset in an array, and each offset corresponds to one
descriptor, with a max limit up to 256 such module BTFs.

We also change existing kfunc_tab to distinguish each element based on
imm, off pair as each such call will now be distinct.

Another change is to check_kfunc_call callback, which now include a
struct module * pointer, this is to be used in later patch such that the
kfunc_id and module pointer are matched for dynamically registered BTF
sets from loadable modules, so that same kfunc_id in two modules doesn't
lead to check_kfunc_call succeeding. For the duration of the
check_kfunc_call, the reference to struct module exists, as it returns
the pointer stored in kfunc_btf_tab.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-2-memxor@gmail.com
2021-10-05 17:07:41 -07:00
Jakub Kicinski
6b7b0c3091 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
bpf-next 2021-10-02

We've added 85 non-merge commits during the last 15 day(s) which contain
a total of 132 files changed, 13779 insertions(+), 6724 deletions(-).

The main changes are:

1) Massive update on test_bpf.ko coverage for JITs as preparatory work for
   an upcoming MIPS eBPF JIT, from Johan Almbladh.

2) Add a batched interface for RX buffer allocation in AF_XDP buffer pool,
   with driver support for i40e and ice from Magnus Karlsson.

3) Add legacy uprobe support to libbpf to complement recently merged legacy
   kprobe support, from Andrii Nakryiko.

4) Add bpf_trace_vprintk() as variadic printk helper, from Dave Marchevsky.

5) Support saving the register state in verifier when spilling <8byte bounded
   scalar to the stack, from Martin Lau.

6) Add libbpf opt-in for stricter BPF program section name handling as part
   of libbpf 1.0 effort, from Andrii Nakryiko.

7) Add a document to help clarifying BPF licensing, from Alexei Starovoitov.

8) Fix skel_internal.h to propagate errno if the loader indicates an internal
   error, from Kumar Kartikeya Dwivedi.

9) Fix build warnings with -Wcast-function-type so that the option can later
   be enabled by default for the kernel, from Kees Cook.

10) Fix libbpf to ignore STT_SECTION symbols in legacy map definitions as it
    otherwise errors out when encountering them, from Toke Høiland-Jørgensen.

11) Teach libbpf to recognize specialized maps (such as for perf RB) and
    internally remove BTF type IDs when creating them, from Hengqi Chen.

12) Various fixes and improvements to BPF selftests.
====================

Link: https://lore.kernel.org/r/20211002001327.15169-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-01 19:58:02 -07:00
Jakub Kicinski
dd9a887b35 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/phy/bcm7xxx.c
  d88fd1b546 ("net: phy: bcm7xxx: Fixed indirect MMD operations")
  f68d08c437 ("net: phy: bcm7xxx: Add EPHY entry for 72165")

net/sched/sch_api.c
  b193e15ac6 ("net: prevent user from passing illegal stab size")
  69508d4333 ("net_sched: Use struct_size() and flex_array_size() helpers")

Both cases trivial - adjacent code additions.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-30 14:49:21 -07:00
Linus Torvalds
4de593fb96 Merge tag 'net-5.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from mac80211, netfilter and bpf.

  Current release - regressions:

   - bpf, cgroup: assign cgroup in cgroup_sk_alloc when called from
     interrupt

   - mdio: revert mechanical patches which broke handling of optional
     resources

   - dev_addr_list: prevent address duplication

  Previous releases - regressions:

   - sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb
     (NULL deref)

   - Revert "mac80211: do not use low data rates for data frames with no
     ack flag", fixing broadcast transmissions

   - mac80211: fix use-after-free in CCMP/GCMP RX

   - netfilter: include zone id in tuple hash again, minimize collisions

   - netfilter: nf_tables: unlink table before deleting it (race -> UAF)

   - netfilter: log: work around missing softdep backend module

   - mptcp: don't return sockets in foreign netns

   - sched: flower: protect fl_walk() with rcu (race -> UAF)

   - ixgbe: fix NULL pointer dereference in ixgbe_xdp_setup

   - smsc95xx: fix stalled rx after link change

   - enetc: fix the incorrect clearing of IF_MODE bits

   - ipv4: fix rtnexthop len when RTA_FLOW is present

   - dsa: mv88e6xxx: 6161: use correct MAX MTU config method for this
     SKU

   - e100: fix length calculation & buffer overrun in ethtool::get_regs

  Previous releases - always broken:

   - mac80211: fix using stale frag_tail skb pointer in A-MSDU tx

   - mac80211: drop frames from invalid MAC address in ad-hoc mode

   - af_unix: fix races in sk_peer_pid and sk_peer_cred accesses (race
     -> UAF)

   - bpf, x86: Fix bpf mapping of atomic fetch implementation

   - bpf: handle return value of BPF_PROG_TYPE_STRUCT_OPS prog

   - netfilter: ip6_tables: zero-initialize fragment offset

   - mhi: fix error path in mhi_net_newlink

   - af_unix: return errno instead of NULL in unix_create1() when over
     the fs.file-max limit

  Misc:

   - bpf: exempt CAP_BPF from checks against bpf_jit_limit

   - netfilter: conntrack: make max chain length random, prevent
     guessing buckets by attackers

   - netfilter: nf_nat_masquerade: make async masq_inet6_event handling
     generic, defer conntrack walk to work queue (prevent hogging RTNL
     lock)"

* tag 'net-5.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits)
  af_unix: fix races in sk_peer_pid and sk_peer_cred accesses
  net: stmmac: fix EEE init issue when paired with EEE capable PHYs
  net: dev_addr_list: handle first address in __hw_addr_add_ex
  net: sched: flower: protect fl_walk() with rcu
  net: introduce and use lock_sock_fast_nested()
  net: phy: bcm7xxx: Fixed indirect MMD operations
  net: hns3: disable firmware compatible features when uninstall PF
  net: hns3: fix always enable rx vlan filter problem after selftest
  net: hns3: PF enable promisc for VF when mac table is overflow
  net: hns3: fix show wrong state when add existing uc mac address
  net: hns3: fix mixed flag HCLGE_FLAG_MQPRIO_ENABLE and HCLGE_FLAG_DCB_ENABLE
  net: hns3: don't rollback when destroy mqprio fail
  net: hns3: remove tc enable checking
  net: hns3: do not allow call hns3_nic_net_open repeatedly
  ixgbe: Fix NULL pointer dereference in ixgbe_xdp_setup
  net: bridge: mcast: Associate the seqcount with its protecting lock.
  net: mdio-ipq4019: Fix the error for an optional regs resource
  net: hns3: fix hclge_dbg_dump_tm_pg() stack usage
  net: mdio: mscc-miim: Fix the mdio controller
  af_unix: Return errno instead of NULL in unix_create1().
  ...
2021-09-30 14:28:05 -07:00
Kees Cook
102acbacfd bpf: Replace callers of BPF_CAST_CALL with proper function typedef
In order to keep ahead of cases in the kernel where Control Flow
Integrity (CFI) may trip over function call casts, enabling
-Wcast-function-type is helpful. To that end, BPF_CAST_CALL causes
various warnings and is one of the last places in the kernel
triggering this warning.

For actual function calls, replace BPF_CAST_CALL() with a typedef, which
captures the same details about the given function pointers.

This change results in no object code difference.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://github.com/KSPP/linux/issues/20
Link: https://lore.kernel.org/lkml/CAEf4Bzb46=-J5Fxc3mMZ8JQPtK1uoE0q6+g6WPz53Cvx=CBEhw@mail.gmail.com
Link: https://lore.kernel.org/bpf/20210928230946.4062144-3-keescook@chromium.org
2021-09-28 16:27:18 -07:00
Kees Cook
3d717fad50 bpf: Replace "want address" users of BPF_CAST_CALL with BPF_CALL_IMM
In order to keep ahead of cases in the kernel where Control Flow
Integrity (CFI) may trip over function call casts, enabling
-Wcast-function-type is helpful. To that end, BPF_CAST_CALL causes
various warnings and is one of the last places in the kernel triggering
this warning.

Most places using BPF_CAST_CALL actually just want a void * to perform
math on. It's not actually performing a call, so just use a different
helper to get the void *, by way of the new BPF_CALL_IMM() helper, which
can clean up a common copy/paste idiom as well.

This change results in no object code difference.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://github.com/KSPP/linux/issues/20
Link: https://lore.kernel.org/lkml/CAEf4Bzb46=-J5Fxc3mMZ8JQPtK1uoE0q6+g6WPz53Cvx=CBEhw@mail.gmail.com
Link: https://lore.kernel.org/bpf/20210928230946.4062144-2-keescook@chromium.org
2021-09-28 16:27:18 -07:00
David S. Miller
4ccb9f03fe Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-09-28

The following pull-request contains BPF updates for your *net* tree.

We've added 10 non-merge commits during the last 14 day(s) which contain
a total of 11 files changed, 139 insertions(+), 53 deletions(-).

The main changes are:

1) Fix MIPS JIT jump code emission for too large offsets, from Piotr Krysiuk.

2) Fix x86 JIT atomic/fetch emission when dst reg maps to rax, from Johan Almbladh.

3) Fix cgroup_sk_alloc corner case when called from interrupt, from Daniel Borkmann.

4) Fix segfault in libbpf's linker for objects without BTF, from Kumar Kartikeya Dwivedi.

5) Fix bpf_jit_charge_modmem for applications with CAP_BPF, from Lorenz Bauer.

6) Fix return value handling for struct_ops BPF programs, from Hou Tao.

7) Various fixes to BPF selftests, from Jiri Benc.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
,
2021-09-28 13:52:46 +01:00
Daniel Borkmann
78cc316e95 bpf, cgroup: Assign cgroup in cgroup_sk_alloc when called from interrupt
If cgroup_sk_alloc() is called from interrupt context, then just assign the
root cgroup to skcd->cgroup. Prior to commit 8520e224f5 ("bpf, cgroups:
Fix cgroup v2 fallback on v1/v2 mixed mode") we would just return, and later
on in sock_cgroup_ptr(), we were NULL-testing the cgroup in fast-path, and
iff indeed NULL returning the root cgroup (v ?: &cgrp_dfl_root.cgrp). Rather
than re-adding the NULL-test to the fast-path we can just assign it once from
cgroup_sk_alloc() given v1/v2 handling has been simplified. The migration from
NULL test with returning &cgrp_dfl_root.cgrp to assigning &cgrp_dfl_root.cgrp
directly does /not/ change behavior for callers of sock_cgroup_ptr().

syzkaller was able to trigger a splat in the legacy netrom code base, where
the RX handler in nr_rx_frame() calls nr_make_new() which calls sk_alloc()
and therefore cgroup_sk_alloc() with in_interrupt() condition. Thus the NULL
skcd->cgroup, where it trips over on cgroup_sk_free() side given it expects
a non-NULL object. There are a few other candidates aside from netrom which
have similar pattern where in their accept-like implementation, they just call
to sk_alloc() and thus cgroup_sk_alloc() instead of sk_clone_lock() with the
corresponding cgroup_sk_clone() which then inherits the cgroup from the parent
socket. None of them are related to core protocols where BPF cgroup programs
are running from. However, in future, they should follow to implement a similar
inheritance mechanism.

Additionally, with a !CONFIG_CGROUP_NET_PRIO and !CONFIG_CGROUP_NET_CLASSID
configuration, the same issue was exposed also prior to 8520e224f5 due to
commit e876ecc67d ("cgroup: memcg: net: do not associate sock with unrelated
cgroup") which added the early in_interrupt() return back then.

Fixes: 8520e224f5 ("bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode")
Fixes: e876ecc67d ("cgroup: memcg: net: do not associate sock with unrelated cgroup")
Reported-by: syzbot+df709157a4ecaf192b03@syzkaller.appspotmail.com
Reported-by: syzbot+533f389d4026d86a2a95@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: syzbot+df709157a4ecaf192b03@syzkaller.appspotmail.com
Tested-by: syzbot+533f389d4026d86a2a95@syzkaller.appspotmail.com
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20210927123921.21535-1-daniel@iogearbox.net
2021-09-28 09:29:19 +02:00
Lorenz Bauer
8a98ae12fb bpf: Exempt CAP_BPF from checks against bpf_jit_limit
When introducing CAP_BPF, bpf_jit_charge_modmem() was not changed to treat
programs with CAP_BPF as privileged for the purpose of JIT memory allocation.
This means that a program without CAP_BPF can block a program with CAP_BPF
from loading a program.

Fix this by checking bpf_capable() in bpf_jit_charge_modmem().

Fixes: 2c78ee898d ("bpf: Implement CAP_BPF")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922111153.19843-1-lmb@cloudflare.com
2021-09-28 09:28:37 +02:00
Martin KaFai Lau
354e8f1970 bpf: Support <8-byte scalar spill and refill
The verifier currently does not save the reg state when
spilling <8byte bounded scalar to the stack.  The bpf program
will be incorrectly rejected when this scalar is refilled to
the reg and then used to offset into a packet header.
The later patch has a simplified bpf prog from a real use case
to demonstrate this case.  The current work around is
to reparse the packet again such that this offset scalar
is close to where the packet data will be accessed to
avoid the spill.  Thus, the header is parsed twice.

The llvm patch [1] will align the <8bytes spill to
the 8-byte stack address.  This can simplify the verifier
support by avoiding to store multiple reg states for
each 8 byte stack slot.

This patch changes the verifier to save the reg state when
spilling <8bytes scalar to the stack.  This reg state saving
is limited to spill aligned to the 8-byte stack address.
The current refill logic has already called coerce_reg_to_size(),
so coerce_reg_to_size() is not called on state->stack[spi].spilled_ptr
during spill.

When refilling in check_stack_read_fixed_off(),  it checks
the refill size is the same as the number of bytes marked with
STACK_SPILL before restoring the reg state.  When restoring
the reg state to state->regs[dst_regno], it needs
to avoid the state->regs[dst_regno].subreg_def being
over written because it has been marked by the check_reg_arg()
earlier [check_mem_access() is called after check_reg_arg() in
do_check()].  Reordering check_mem_access() and check_reg_arg()
will need a lot of changes in test_verifier's tests because
of the difference in verifier's error message.  Thus, the
patch here is to save the state->regs[dst_regno].subreg_def
first in check_stack_read_fixed_off().

There are cases that the verifier needs to scrub the spilled slot
from STACK_SPILL to STACK_MISC.  After this patch the spill is not always
in 8 bytes now, so it can no longer assume the other 7 bytes are always
marked as STACK_SPILL.  In particular, the scrub needs to avoid marking
an uninitialized byte from STACK_INVALID to STACK_MISC.  Otherwise, the
verifier will incorrectly accept bpf program reading uninitialized bytes
from the stack.  A new helper scrub_spilled_slot() is created for this
purpose.

[1]: https://reviews.llvm.org/D109073

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210922004941.625398-1-kafai@fb.com
2021-09-26 13:07:27 -07:00
Martin KaFai Lau
27113c59b6 bpf: Check the other end of slot_type for STACK_SPILL
Every 8 bytes of the stack is tracked by a bpf_stack_state.
Within each bpf_stack_state, there is a 'u8 slot_type[8]' to track
the type of each byte.  Verifier tests slot_type[0] == STACK_SPILL
to decide if the spilled reg state is saved.  Verifier currently only
saves the reg state if the whole 8 bytes are spilled to the stack,
so checking the slot_type[7] is the same as checking slot_type[0].

The later patch will allow verifier to save the bounded scalar
reg also for <8 bytes spill.  There is a llvm patch [1] to ensure
the <8 bytes spill will be 8-byte aligned,  so checking
slot_type[7] instead of slot_type[0] is required.

While at it, this patch refactors the slot_type[0] == STACK_SPILL
test into a new function is_spilled_reg() and change the
slot_type[0] check to slot_type[7] check in there also.

[1] https://reviews.llvm.org/D109073

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210922004934.624194-1-kafai@fb.com
2021-09-26 13:07:27 -07:00
Linus Torvalds
3a398acc56 Merge tag 'timers-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A single fix for the recently introduced regression in posix CPU
  timers which failed to stop the timer when requested. That caused
  unexpected signals to be sent to the process/thread causing
  malfunction"

* tag 'timers-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Prevent spuriously armed 0-value itimer
2021-09-26 10:00:16 -07:00
Linus Torvalds
dc0f97c261 Merge tag 'irq-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Work around a bad GIC integration on a Renesas platform which can't
     handle byte-sized MMIO access

   - Plug a potential memory leak in the GICv4 driver

   - Fix a regression in the Armada 370-XP IPI code which was caused by
     issuing EOI instack of ACK.

   - A couple of small fixes here and there"

* tag 'irq-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic: Work around broken Renesas integration
  irqchip/renesas-rza1: Use semicolons instead of commas
  irqchip/gic-v3-its: Fix potential VPE leak on error
  irqchip/goldfish-pic: Select GENERIC_IRQ_CHIP to fix build
  irqchip/mbigen: Repair non-kernel-doc notation
  irqdomain: Change the type of 'size' in __irq_domain_add() to be consistent
  irqchip/armada-370-xp: Fix ack/eoi breakage
  Documentation: Fix irq-domain.rst build warning
2021-09-26 09:55:22 -07:00
Linus Torvalds
2d70de4ee5 Merge tag 'block-5.15-2021-09-25' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:

 - NVMe pull request via Christoph:
      - keep ctrl->namespaces ordered (Christoph Hellwig)
      - fix incorrect h2cdata pdu offset accounting in nvme-tcp (Sagi
        Grimberg)
      - handled updated hw_queues in nvme-fc more carefully (Daniel
        Wagner, James Smart)

 - md lock order fix (Christoph)

 - fallocate locking fix (Ming)

 - blktrace UAF fix (Zhihao)

 - rq-qos bio tracking fix (Ming)

* tag 'block-5.15-2021-09-25' of git://git.kernel.dk/linux-block:
  block: hold ->invalidate_lock in blkdev_fallocate
  blktrace: Fix uaf in blk_trace access after removing by sysfs
  block: don't call rq_qos_ops->done_bio if the bio isn't tracked
  md: fix a lock order reversal in md_alloc
  nvme: keep ctrl->namespaces ordered
  nvme-tcp: fix incorrect h2cdata pdu offset accounting
  nvme-fc: remove freeze/unfreeze around update_nr_hw_queues
  nvme-fc: avoid race between time out and tear down
  nvme-fc: update hardware queues before using them
2021-09-25 15:44:05 -07:00
Zhihao Cheng
5afedf670c blktrace: Fix uaf in blk_trace access after removing by sysfs
There is an use-after-free problem triggered by following process:

      P1(sda)				P2(sdb)
			echo 0 > /sys/block/sdb/trace/enable
			  blk_trace_remove_queue
			    synchronize_rcu
			    blk_trace_free
			      relay_close
rcu_read_lock
__blk_add_trace
  trace_note_tsk
  (Iterate running_trace_list)
			        relay_close_buf
				  relay_destroy_buf
				    kfree(buf)
    trace_note(sdb's bt)
      relay_reserve
        buf->offset <- nullptr deference (use-after-free) !!!
rcu_read_unlock

[  502.714379] BUG: kernel NULL pointer dereference, address:
0000000000000010
[  502.715260] #PF: supervisor read access in kernel mode
[  502.715903] #PF: error_code(0x0000) - not-present page
[  502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0
[  502.717252] Oops: 0000 [#1] SMP
[  502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360
[  502.732872] Call Trace:
[  502.733193]  __blk_add_trace.cold+0x137/0x1a3
[  502.733734]  blk_add_trace_rq+0x7b/0xd0
[  502.734207]  blk_add_trace_rq_issue+0x54/0xa0
[  502.734755]  blk_mq_start_request+0xde/0x1b0
[  502.735287]  scsi_queue_rq+0x528/0x1140
...
[  502.742704]  sg_new_write.isra.0+0x16e/0x3e0
[  502.747501]  sg_ioctl+0x466/0x1100

Reproduce method:
  ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sda, BLKTRACESTART)
  ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sdb, BLKTRACESTART)

  echo 0 > /sys/block/sdb/trace/enable &
  // Add delay(mdelay/msleep) before kernel enters blk_trace_free()

  ioctl$SG_IO(/dev/sda, SG_IO, ...)
  // Enters trace_note_tsk() after blk_trace_free() returned
  // Use mdelay in rcu region rather than msleep(which may schedule out)

Remove blk_trace from running_list before calling blk_trace_free() by
sysfs if blk_trace is at Blktrace_running state.

Fixes: c71a896154 ("blktrace: add ftrace plugin")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 11:06:15 -06:00
Thomas Gleixner
f9bfed3ad5 Merge tag 'irqchip-fixes-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent
Pull irqchip fixes from Marc Zyngier:

 - Work around a bad GIC integration on a Renesas platform, where the
   interconnect cannot deal with byte-sized MMIO accesses

 - Cleanup another Renesas driver abusing the comma operator

 - Fix a potential GICv4 memory leak on an error path

 - Make the type of 'size' consistent with the rest of the code in
   __irq_domain_add()

 - Fix a regression in the Armada 370-XP IPI path

 - Fix the build for the obviously unloved goldfish-pic

 - Some documentation fixes

Link: https://lore.kernel.org/r/20210924090933.2766857-1-maz@kernel.org
2021-09-24 14:11:04 +02:00
Jakub Kicinski
2fcd14d0f7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
net/mptcp/protocol.c
  977d293e23 ("mptcp: ensure tx skbs always have the MPTCP ext")
  efe686ffce ("mptcp: ensure tx skbs always have the MPTCP ext")

same patch merged in both trees, keep net-next.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-23 11:19:49 -07:00
Frederic Weisbecker
8cd9da85d2 posix-cpu-timers: Prevent spuriously armed 0-value itimer
Resetting/stopping an itimer eventually leads to it being reprogrammed
with an actual "0" value. As a result the itimer expires on the next
tick, triggering an unexpected signal.

To fix this, make sure that
struct signal_struct::it[CPUCLOCK_PROF/VIRT]::expires is set to 0 when
setitimer() passes a 0 it_value, indicating that the timer must stop.

Fixes: 406dd42bd1 ("posix-cpu-timers: Force next expiration recalc after itimer reset")
Reported-by: Victor Stinner <vstinner@redhat.com>
Reported-by: Chris Hixon <linux-kernel-bugs@hixontech.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210913145332.232023-1-frederic@kernel.org
2021-09-23 11:53:51 +02:00
Sean Christopherson
a68de80f61 entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume()
Invoke rseq_handle_notify_resume() from tracehook_notify_resume() now
that the two function are always called back-to-back by architectures
that have rseq.  The rseq helper is stubbed out for architectures that
don't support rseq, i.e. this is a nop across the board.

Note, tracehook_notify_resume() is horribly named and arguably does not
belong in tracehook.h as literally every line of code in it has nothing
to do with tracing.  But, that's been true since commit a42c6ded82
("move key_repace_session_keyring() into tracehook_notify_resume()")
first usurped tracehook_notify_resume() back in 2012.  Punt cleaning that
mess up to future patches.

No functional change intended.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210901203030.1292304-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22 10:24:01 -04:00
Sean Christopherson
8646e53633 KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest
Invoke rseq's NOTIFY_RESUME handler when processing the flag prior to
transferring to a KVM guest, which is roughly equivalent to an exit to
userspace and processes many of the same pending actions.  While the task
cannot be in an rseq critical section as the KVM path is reachable only
by via ioctl(KVM_RUN), the side effects that apply to rseq outside of a
critical section still apply, e.g. the current CPU needs to be updated if
the task is migrated.

Clearing TIF_NOTIFY_RESUME without informing rseq can lead to segfaults
and other badness in userspace VMMs that use rseq in combination with KVM,
e.g. due to the CPU ID being stale after task migration.

Fixes: 72c3c0fe54 ("x86/kvm: Use generic xfer to guest work function")
Reported-by: Peter Foley <pefoley@google.com>
Bisected-by: Doug Evans <dje@google.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210901203030.1292304-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22 10:24:01 -04:00
Bixuan Cui
20c36ce216 irqdomain: Change the type of 'size' in __irq_domain_add() to be consistent
The 'size' is used in struct_size(domain, revmap, size) and its input
parameter type is 'size_t'(unsigned int).
Changing the size to 'unsigned int' to make the type consistent.

Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210916025203.44841-1-cuibixuan@huawei.com
2021-09-22 14:29:32 +01:00
Linus Torvalds
fec3036200 Merge tag 'perf-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event fix from Thomas Gleixner:
 "A single fix for the perf core where a value read with READ_ONCE() was
  checked and then reread which makes all the checks invalid. Reuse the
  already read value instead"

* tag 'perf-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  events: Reuse value read using READ_ONCE instead of re-reading it
2021-09-19 13:22:40 -07:00
Linus Torvalds
f5e29a26c4 Merge tag 'locking-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "A set of updates for the RT specific reader/writer locking base code:

   - Make the fast path reader ordering guarantees correct.

   - Code reshuffling to make the fix simpler"

[ This plays ugly games with atomic_add_return_release() because we
  don't have a plain atomic_add_release(), and should really be cleaned
  up, I think    - Linus ]

* tag 'locking-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwbase: Take care of ordering guarantee for fastpath reader
  locking/rwbase: Extract __rwbase_write_trylock()
  locking/rwbase: Properly match set_and_save_state() to restore_state()
2021-09-19 13:11:19 -07:00
Dave Marchevsky
10aceb629e bpf: Add bpf_trace_vprintk helper
This helper is meant to be "bpf_trace_printk, but with proper vararg
support". Follow bpf_snprintf's example and take a u64 pseudo-vararg
array. Write to /sys/kernel/debug/tracing/trace_pipe using the same
mechanism as bpf_trace_printk. The functionality of this helper was
requested in the libbpf issue tracker [0].

[0] Closes: https://github.com/libbpf/libbpf/issues/315

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-4-davemarchevsky@fb.com
2021-09-17 14:02:05 -07:00
Dave Marchevsky
335ff4990c bpf: Merge printk and seq_printf VARARG max macros
MAX_SNPRINTF_VARARGS and MAX_SEQ_PRINTF_VARARGS are used by bpf helpers
bpf_snprintf and bpf_seq_printf to limit their varargs. Both call into
bpf_bprintf_prepare for print formatting logic and have convenience
macros in libbpf (BPF_SNPRINTF, BPF_SEQ_PRINTF) which use the same
helper macros to convert varargs to a byte array.

Changing shared functionality to support more varargs for either bpf
helper would affect the other as well, so let's combine the _VARARGS
macros to make this more obvious.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-2-davemarchevsky@fb.com
2021-09-17 14:02:05 -07:00
Jakub Kicinski
af54faab84 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-09-17

We've added 63 non-merge commits during the last 12 day(s) which contain
a total of 65 files changed, 2653 insertions(+), 751 deletions(-).

The main changes are:

1) Streamline internal BPF program sections handling and
   bpf_program__set_attach_target() in libbpf, from Andrii.

2) Add support for new btf kind BTF_KIND_TAG, from Yonghong.

3) Introduce bpf_get_branch_snapshot() to capture LBR, from Song.

4) IMUL optimization for x86-64 JIT, from Jie.

5) xsk selftest improvements, from Magnus.

6) Introduce legacy kprobe events support in libbpf, from Rafael.

7) Access hw timestamp through BPF's __sk_buff, from Vadim.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits)
  selftests/bpf: Fix a few compiler warnings
  libbpf: Constify all high-level program attach APIs
  libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7
  selftests/bpf: Switch fexit_bpf2bpf selftest to set_attach_target() API
  libbpf: Allow skipping attach_func_name in bpf_program__set_attach_target()
  libbpf: Deprecated bpf_object_open_opts.relaxed_core_relocs
  selftests/bpf: Stop using relaxed_core_relocs which has no effect
  libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id()
  bpf: Update bpf_get_smp_processor_id() documentation
  libbpf: Add sphinx code documentation comments
  selftests/bpf: Skip btf_tag test if btf_tag attribute not supported
  docs/bpf: Add documentation for BTF_KIND_TAG
  selftests/bpf: Add a test with a bpf program with btf_tag attributes
  selftests/bpf: Test BTF_KIND_TAG for deduplication
  selftests/bpf: Add BTF_KIND_TAG unit tests
  selftests/bpf: Change NAME_NTH/IS_NAME_NTH for BTF_KIND_TAG format
  selftests/bpf: Test libbpf API function btf__add_tag()
  bpftool: Add support for BTF_KIND_TAG
  libbpf: Add support for BTF_KIND_TAG
  libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tag
  ...
====================

Link: https://lore.kernel.org/r/20210917173738.3397064-1-ast@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-17 12:40:21 -07:00
Linus Torvalds
b9b11b133b Merge tag 'dma-mapping-5.15-1' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:

 - page align size in sparc32 arch_dma_alloc (Andreas Larsson)

 - tone down a new dma-debug message (Hamza Mahfooz)

 - fix the kerneldoc for dma_map_sg_attrs (me)

* tag 'dma-mapping-5.15-1' of git://git.infradead.org/users/hch/dma-mapping:
  sparc32: page align size in arch_dma_alloc
  dma-debug: prevent an error message from causing runtime problems
  dma-mapping: fix the kerneldoc for dma_map_sg_attrs
2021-09-17 11:54:48 -07:00
Linus Torvalds
fc0c0548c1 Merge tag 'net-5.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf.

  Current release - regressions:

   - vhost_net: fix OoB on sendmsg() failure

   - mlx5: bridge, fix uninitialized variable usage

   - bnxt_en: fix error recovery regression

  Current release - new code bugs:

   - bpf, mm: fix lockdep warning triggered by stack_map_get_build_id_offset()

  Previous releases - regressions:

   - r6040: restore MDIO clock frequency after MAC reset

   - tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()

   - dsa: flush switchdev workqueue before tearing down CPU/DSA ports

  Previous releases - always broken:

   - ptp: dp83640: don't define PAGE0, avoid compiler warning

   - igc: fix tunnel segmentation offloads

   - phylink: update SFP selected interface on advertising changes

   - stmmac: fix system hang caused by eee_ctrl_timer during suspend/resume

   - mlx5e: fix mutual exclusion between CQE compression and HW TS

  Misc:

   - bpf, cgroups: fix cgroup v2 fallback on v1/v2 mixed mode

   - sfc: fallback for lack of xdp tx queues

   - hns3: add option to turn off page pool feature"

* tag 'net-5.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (67 commits)
  mlxbf_gige: clear valid_polarity upon open
  igc: fix tunnel offloading
  net/{mlx5|nfp|bnxt}: Remove unnecessary RTNL lock assert
  net: wan: wanxl: define CROSS_COMPILE_M68K
  selftests: nci: replace unsigned int with int
  net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports
  Revert "net: phy: Uniform PHY driver access"
  net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup
  ptp: dp83640: don't define PAGE0
  bnx2x: Fix enabling network interfaces without VFs
  Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers""
  tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()
  net-caif: avoid user-triggerable WARN_ON(1)
  bpf, selftests: Add test case for mixed cgroup v1/v2
  bpf, selftests: Add cgroup v1 net_cls classid helpers
  bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode
  bpf: Add oversize check before call kvcalloc()
  net: hns3: fix the timing issue of VF clearing interrupt sources
  net: hns3: fix the exception when query imp info
  net: hns3: disable mac in flr process
  ...
2021-09-16 13:05:42 -07:00
Boqun Feng
81121524f1 locking/rwbase: Take care of ordering guarantee for fastpath reader
Readers of rwbase can lock and unlock without taking any inner lock, if
that happens, we need the ordering provided by atomic operations to
satisfy the ordering semantics of lock/unlock. Without that, considering
the follow case:

	{ X = 0 initially }

	CPU 0			CPU 1
	=====			=====
				rt_write_lock();
				X = 1
				rt_write_unlock():
				  atomic_add(READER_BIAS - WRITER_BIAS, ->readers);
				  // ->readers is READER_BIAS.
	rt_read_lock():
	  if ((r = atomic_read(->readers)) < 0) // True
	    atomic_try_cmpxchg(->readers, r, r + 1); // succeed.
	  <acquire the read lock via fast path>

	r1 = X;	// r1 may be 0, because nothing prevent the reordering
	        // of "X=1" and atomic_add() on CPU 1.

Therefore audit every usage of atomic operations that may happen in a
fast path, and add necessary barriers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20210909110203.953991276@infradead.org
2021-09-15 17:49:16 +02:00
Peter Zijlstra
616be87eac locking/rwbase: Extract __rwbase_write_trylock()
The code in rwbase_write_lock() is a little non-obvious vs the
read+set 'trylock', extract the sequence into a helper function to
clarify the code.

This also provides a single site to fix fast-path ordering.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/YUCq3L+u44NDieEJ@hirez.programming.kicks-ass.net
2021-09-15 17:49:15 +02:00
Peter Zijlstra
7687201e37 locking/rwbase: Properly match set_and_save_state() to restore_state()
Noticed while looking at the readers race.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20210909110203.828203010@infradead.org
2021-09-15 17:49:15 +02:00
Baptiste Lepers
b89a05b21f events: Reuse value read using READ_ONCE instead of re-reading it
In perf_event_addr_filters_apply, the task associated with
the event (event->ctx->task) is read using READ_ONCE at the beginning
of the function, checked, and then re-read from event->ctx->task,
voiding all guarantees of the checks. Reuse the value that was read by
READ_ONCE to ensure the consistency of the task struct throughout the
function.

Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210906015310.12802-1-baptiste.lepers@gmail.com
2021-09-15 17:49:06 +02:00
Yonghong Song
b5ea834dde bpf: Support for new btf kind BTF_KIND_TAG
LLVM14 added support for a new C attribute ([1])
  __attribute__((btf_tag("arbitrary_str")))
This attribute will be emitted to dwarf ([2]) and pahole
will convert it to BTF. Or for bpf target, this
attribute will be emitted to BTF directly ([3], [4]).
The attribute is intended to provide additional
information for
  - struct/union type or struct/union member
  - static/global variables
  - static/global function or function parameter.

For linux kernel, the btf_tag can be applied
in various places to specify user pointer,
function pre- or post- condition, function
allow/deny in certain context, etc. Such information
will be encoded in vmlinux BTF and can be used
by verifier.

The btf_tag can also be applied to bpf programs
to help global verifiable functions, e.g.,
specifying preconditions, etc.

This patch added basic parsing and checking support
in kernel for new BTF_KIND_TAG kind.

 [1] https://reviews.llvm.org/D106614
 [2] https://reviews.llvm.org/D106621
 [3] https://reviews.llvm.org/D106622
 [4] https://reviews.llvm.org/D109560

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223015.245546-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Linus Torvalds
77e02cf57b memblock: introduce saner 'memblock_free_ptr()' interface
The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.

Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:

   https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/

or just random memory corruption if the debug checks don't catch it:

   https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/

I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.

I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.

So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer.  And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 40caa127f3 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-14 13:23:22 -07:00
Hou Tao
356ed64991 bpf: Handle return value of BPF_PROG_TYPE_STRUCT_OPS prog
Currently if a function ptr in struct_ops has a return value, its
caller will get a random return value from it, because the return
value of related BPF_PROG_TYPE_STRUCT_OPS prog is just dropped.

So adding a new flag BPF_TRAMP_F_RET_FENTRY_RET to tell bpf trampoline
to save and return the return value of struct_ops prog if ret_size of
the function ptr is greater than 0. Also restricting the flag to be
used alone.

Fixes: 85d33df357 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914023351.3664499-1-houtao1@huawei.com
2021-09-14 11:09:50 -07:00