Commit Graph

34186 Commits

Author SHA1 Message Date
Linus Torvalds
7fe10096c1 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
 "This fixes a regression in padata"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  padata: fix possible padata_works_lock deadlock
2020-09-09 19:46:22 -07:00
Yonghong Song
7c69673262 bpf: Permit map_ptr arithmetic with opcode add and offset 0
Commit 41c48f3a98 ("bpf: Support access
to bpf map fields") added support to access map fields
with CORE support. For example,

            struct bpf_map {
                    __u32 max_entries;
            } __attribute__((preserve_access_index));

            struct bpf_array {
                    struct bpf_map map;
                    __u32 elem_size;
            } __attribute__((preserve_access_index));

            struct {
                    __uint(type, BPF_MAP_TYPE_ARRAY);
                    __uint(max_entries, 4);
                    __type(key, __u32);
                    __type(value, __u32);
            } m_array SEC(".maps");

            SEC("cgroup_skb/egress")
            int cg_skb(void *ctx)
            {
                    struct bpf_array *array = (struct bpf_array *)&m_array;

                    /* .. array->map.max_entries .. */
            }

In kernel, bpf_htab has similar structure,

	    struct bpf_htab {
		    struct bpf_map map;
                    ...
            }

In the above cg_skb(), to access array->map.max_entries, with CORE, the clang will
generate two builtin's.
            base = &m_array;
            /* access array.map */
            map_addr = __builtin_preserve_struct_access_info(base, 0, 0);
            /* access array.map.max_entries */
            max_entries_addr = __builtin_preserve_struct_access_info(map_addr, 0, 0);
	    max_entries = *max_entries_addr;

In the current llvm, if two builtin's are in the same function or
in the same function after inlining, the compiler is smart enough to chain
them together and generates like below:
            base = &m_array;
            max_entries = *(base + reloc_offset); /* reloc_offset = 0 in this case */
and we are fine.

But if we force no inlining for one of functions in test_map_ptr() selftest, e.g.,
check_default(), the above two __builtin_preserve_* will be in two different
functions. In this case, we will have code like:
   func check_hash():
            reloc_offset_map = 0;
            base = &m_array;
            map_base = base + reloc_offset_map;
            check_default(map_base, ...)
   func check_default(map_base, ...):
            max_entries = *(map_base + reloc_offset_max_entries);

In kernel, map_ptr (CONST_PTR_TO_MAP) does not allow any arithmetic.
The above "map_base = base + reloc_offset_map" will trigger a verifier failure.
  ; VERIFY(check_default(&hash->map, map));
  0: (18) r7 = 0xffffb4fe8018a004
  2: (b4) w1 = 110
  3: (63) *(u32 *)(r7 +0) = r1
   R1_w=invP110 R7_w=map_value(id=0,off=4,ks=4,vs=8,imm=0) R10=fp0
  ; VERIFY_TYPE(BPF_MAP_TYPE_HASH, check_hash);
  4: (18) r1 = 0xffffb4fe8018a000
  6: (b4) w2 = 1
  7: (63) *(u32 *)(r1 +0) = r2
   R1_w=map_value(id=0,off=0,ks=4,vs=8,imm=0) R2_w=invP1 R7_w=map_value(id=0,off=4,ks=4,vs=8,imm=0) R10=fp0
  8: (b7) r2 = 0
  9: (18) r8 = 0xffff90bcb500c000
  11: (18) r1 = 0xffff90bcb500c000
  13: (0f) r1 += r2
  R1 pointer arithmetic on map_ptr prohibited

To fix the issue, let us permit map_ptr + 0 arithmetic which will
result in exactly the same map_ptr.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200908175702.2463625-1-yhs@fb.com
2020-09-08 18:02:18 -07:00
Tycho Andersen
e839317900 seccomp: don't leave dangling ->notif if file allocation fails
Christian and Kees both pointed out that this is a bit sloppy to open-code
both places, and Christian points out that we leave a dangling pointer to
->notif if file allocation fails. Since we check ->notif for null in order
to determine if it's ok to install a filter, this means people won't be
able to install a filter if the file allocation fails for some reason, even
if they subsequently should be able to.

To fix this, let's hoist this free+null into its own little helper and use
it.

Reported-by: Kees Cook <keescook@chromium.org>
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200902140953.1201956-1-tycho@tycho.pizza
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-09-08 11:30:16 -07:00
Tycho Andersen
a566a9012a seccomp: don't leak memory when filter install races
In seccomp_set_mode_filter() with TSYNC | NEW_LISTENER, we first initialize
the listener fd, then check to see if we can actually use it later in
seccomp_may_assign_mode(), which can fail if anyone else in our thread
group has installed a filter and caused some divergence. If we can't, we
partially clean up the newly allocated file: we put the fd, put the file,
but don't actually clean up the *memory* that was allocated at
filter->notif. Let's clean that up too.

To accomplish this, let's hoist the actual "detach a notifier from a
filter" code to its own helper out of seccomp_notify_release(), so that in
case anyone adds stuff to init_listener(), they only have to add the
cleanup code in one spot. This does a bit of extra locking and such on the
failure path when the filter is not attached, but it's a slow failure path
anyway.

Fixes: 51891498f2 ("seccomp: allow TSYNC and USER_NOTIF together")
Reported-by: syzbot+3ad9614a12f80994c32e@syzkaller.appspotmail.com
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200902014017.934315-1-tycho@tycho.pizza
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-09-08 11:19:50 -07:00
Linus Torvalds
015b3155c4 Merge tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:

 - more generic entry code ABI fallout

 - debug register handling bugfixes

 - fix vmalloc mappings on 32-bit kernels

 - kprobes instrumentation output fix on 32-bit kernels

 - fix over-eager WARN_ON_ONCE() on !SMAP hardware

 - NUMA debugging fix

 - fix Clang related crash on !RETPOLINE kernels

* tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry: Unbreak 32bit fast syscall
  x86/debug: Allow a single level of #DB recursion
  x86/entry: Fix AC assertion
  tracing/kprobes, x86/ptrace: Fix regs argument order for i386
  x86, fakenuma: Fix invalid starting node ID
  x86/mm/32: Bring back vmalloc faulting on x86_32
  x86/cmdline: Disable jump tables for cmdline.c
2020-09-06 10:28:00 -07:00
Linus Torvalds
7514c0362f Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "19 patches.

  Subsystems affected by this patch series: MAINTAINERS, ipc, fork,
  checkpatch, lib, and mm (memcg, slub, pagemap, madvise, migration,
  hugetlb)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/log2.h: add missing () around n in roundup_pow_of_two()
  mm/khugepaged.c: fix khugepaged's request size in collapse_file
  mm/hugetlb: fix a race between hugetlb sysctl handlers
  mm/hugetlb: try preferred node first when alloc gigantic page from cma
  mm/migrate: preserve soft dirty in remove_migration_pte()
  mm/migrate: remove unnecessary is_zone_device_page() check
  mm/rmap: fixup copying of soft dirty and uffd ptes
  mm/migrate: fixup setting UFFD_WP flag
  mm: madvise: fix vma user-after-free
  checkpatch: fix the usage of capture group ( ... )
  fork: adjust sysctl_max_threads definition to match prototype
  ipc: adjust proc_ipc_sem_dointvec definition to match prototype
  mm: track page table modifications in __apply_to_page_range()
  MAINTAINERS: IA64: mark Status as Odd Fixes only
  MAINTAINERS: add LLVM maintainers
  MAINTAINERS: update Cavium/Marvell entries
  mm: slub: fix conversion of freelist_corrupted()
  mm: memcg: fix memcg reclaim soft lockup
  memcg: fix use-after-free in uncharge_batch
2020-09-05 13:28:40 -07:00
Tobias Klauser
b0daa2c73f fork: adjust sysctl_max_threads definition to match prototype
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer.  Adjust the
definition of sysctl_max_threads to match its prototype in
linux/sysctl.h which fixes the following sparse error/warning:

  kernel/fork.c:3050:47: warning: incorrect type in argument 3 (different address spaces)
  kernel/fork.c:3050:47:    expected void *
  kernel/fork.c:3050:47:    got void [noderef] __user *buffer
  kernel/fork.c:3036:5: error: symbol 'sysctl_max_threads' redeclared with different type (incompatible argument 3 (different address spaces)):
  kernel/fork.c:3036:5:    int extern [addressable] [signed] [toplevel] sysctl_max_threads( ... )
  kernel/fork.c: note: in included file (through include/linux/key.h, include/linux/cred.h, include/linux/sched/signal.h, include/linux/sched/cputime.h):
  include/linux/sysctl.h:242:5: note: previously declared as:
  include/linux/sysctl.h:242:5:    int extern [addressable] [signed] [toplevel] sysctl_max_threads( ... )

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200825093647.24263-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-05 12:14:29 -07:00
Jakub Kicinski
44a8c4f33c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.

Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-04 21:28:59 -07:00
Leon Romanovsky
cfc905f158 gcov: Disable gcov build with GCC 10
GCOV built with GCC 10 doesn't initialize n_function variable.  This
produces different kernel panics as was seen by Colin in Ubuntu and me
in FC 32.

As a workaround, let's disable GCOV build for broken GCC 10 version.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288
Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org
Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-04 09:19:49 -07:00
Thomas Gleixner
4facb95b7a x86/entry: Unbreak 32bit fast syscall
Andy reported that the syscall treacing for 32bit fast syscall fails:

# ./tools/testing/selftests/x86/ptrace_syscall_32
...
[RUN] SYSEMU
[FAIL] Initial args are wrong (nr=224, args=10 11 12 13 14 4289172732)
...
[RUN] SYSCALL
[FAIL] Initial args are wrong (nr=29, args=0 0 0 0 0 4289172732)
 
The eason is that the conversion to generic entry code moved the retrieval
of the sixth argument (EBP) after the point where the syscall entry work
runs, i.e. ptrace, seccomp, audit...

Unbreak it by providing a split up version of syscall_enter_from_user_mode().

- syscall_enter_from_user_mode_prepare() establishes state and enables
  interrupts

- syscall_enter_from_user_mode_work() runs the entry work

Replace the call to syscall_enter_from_user_mode() in the 32bit fast
syscall C-entry with the split functions and stick the EBP retrieval
between them.

Fixes: 27d6b4d14f ("x86/entry: Use generic syscall entry function")
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87k0xdjbtt.fsf@nanos.tec.linutronix.de
2020-09-04 15:50:14 +02:00
Daniel Jordan
1b0df11fde padata: fix possible padata_works_lock deadlock
syzbot reports,

  WARNING: inconsistent lock state
  5.9.0-rc2-syzkaller #0 Not tainted
  --------------------------------
  inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
  syz-executor.0/26715 takes:
  (padata_works_lock){+.?.}-{2:2}, at: padata_do_parallel kernel/padata.c:220
  {IN-SOFTIRQ-W} state was registered at:
    spin_lock include/linux/spinlock.h:354 [inline]
    padata_do_parallel kernel/padata.c:220
    ...
    __do_softirq kernel/softirq.c:298
    ...
    sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1091
    asm_sysvec_apic_timer_interrupt arch/x86/include/asm/idtentry.h:581

   Possible unsafe locking scenario:

         CPU0
         ----
    lock(padata_works_lock);
    <Interrupt>
      lock(padata_works_lock);

padata_do_parallel() takes padata_works_lock with softirqs enabled, so a
deadlock is possible if, on the same CPU, the lock is acquired in
process context and then softirq handling done in an interrupt leads to
the same path.

Fix by leaving softirqs disabled while do_parallel holds
padata_works_lock.

Reported-by: syzbot+f4b9f49e38e25eb4ef52@syzkaller.appspotmail.com
Fixes: 4611ce2246 ("padata: allocate work structures for parallel jobs from a pool")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-04 17:51:55 +10:00
Linus Torvalds
3e8d3bdc2a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi
    Kivilinna.

 2) Fix loss of RTT samples in rxrpc, from David Howells.

 3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu.

 4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka.

 5) We disable BH for too lokng in sctp_get_port_local(), add a
    cond_resched() here as well, from Xin Long.

 6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu.

 7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from
    Yonghong Song.

 8) Missing of_node_put() in mt7530 DSA driver, from Sumera
    Priyadarsini.

 9) Fix crash in bnxt_fw_reset_task(), from Michael Chan.

10) Fix geneve tunnel checksumming bug in hns3, from Yi Li.

11) Memory leak in rxkad_verify_response, from Dinghao Liu.

12) In tipc, don't use smp_processor_id() in preemptible context. From
    Tuong Lien.

13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu.

14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter.

15) Fix ABI mismatch between driver and firmware in nfp, from Louis
    Peens.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits)
  net/smc: fix sock refcounting in case of termination
  net/smc: reset sndbuf_desc if freed
  net/smc: set rx_off for SMCR explicitly
  net/smc: fix toleration of fake add_link messages
  tg3: Fix soft lockup when tg3_reset_task() fails.
  doc: net: dsa: Fix typo in config code sample
  net: dp83867: Fix WoL SecureOn password
  nfp: flower: fix ABI mismatch between driver and firmware
  tipc: fix shutdown() of connectionless socket
  ipv6: Fix sysctl max for fib_multipath_hash_policy
  drivers/net/wan/hdlc: Change the default of hard_header_len to 0
  net: gemini: Fix another missing clk_disable_unprepare() in probe
  net: bcmgenet: fix mask check in bcmgenet_validate_flow()
  amd-xgbe: Add support for new port mode
  net: usb: dm9601: Add USB ID of Keenetic Plus DSL
  vhost: fix typo in error message
  net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init()
  pktgen: fix error message with wrong function name
  net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode
  cxgb4: fix thermal zone device registration
  ...
2020-09-03 18:50:48 -07:00
Yonghong Song
dc0988bbe1 bpf: Do not use bucket_lock for hashmap iterator
Currently, for hashmap, the bpf iterator will grab a bucket lock, a
spinlock, before traversing the elements in the bucket. This can ensure
all bpf visted elements are valid. But this mechanism may cause
deadlock if update/deletion happens to the same bucket of the
visited map in the program. For example, if we added bpf_map_update_elem()
call to the same visited element in selftests bpf_iter_bpf_hash_map.c,
we will have the following deadlock:

  ============================================
  WARNING: possible recursive locking detected
  5.9.0-rc1+ #841 Not tainted
  --------------------------------------------
  test_progs/1750 is trying to acquire lock:
  ffff9a5bb73c5e70 (&htab->buckets[i].raw_lock){....}-{2:2}, at: htab_map_update_elem+0x1cf/0x410

  but task is already holding lock:
  ffff9a5bb73c5e20 (&htab->buckets[i].raw_lock){....}-{2:2}, at: bpf_hash_map_seq_find_next+0x94/0x120

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&htab->buckets[i].raw_lock);
    lock(&htab->buckets[i].raw_lock);

   *** DEADLOCK ***
   ...
  Call Trace:
   dump_stack+0x78/0xa0
   __lock_acquire.cold.74+0x209/0x2e3
   lock_acquire+0xba/0x380
   ? htab_map_update_elem+0x1cf/0x410
   ? __lock_acquire+0x639/0x20c0
   _raw_spin_lock_irqsave+0x3b/0x80
   ? htab_map_update_elem+0x1cf/0x410
   htab_map_update_elem+0x1cf/0x410
   ? lock_acquire+0xba/0x380
   bpf_prog_ad6dab10433b135d_dump_bpf_hash_map+0x88/0xa9c
   ? find_held_lock+0x34/0xa0
   bpf_iter_run_prog+0x81/0x16e
   __bpf_hash_map_seq_show+0x145/0x180
   bpf_seq_read+0xff/0x3d0
   vfs_read+0xad/0x1c0
   ksys_read+0x5f/0xe0
   do_syscall_64+0x33/0x40
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  ...

The bucket_lock first grabbed in seq_ops->next() called by bpf_seq_read(),
and then grabbed again in htab_map_update_elem() in the bpf program, causing
deadlocks.

Actually, we do not need bucket_lock here, we can just use rcu_read_lock()
similar to netlink iterator where the rcu_read_{lock,unlock} likes below:
 seq_ops->start():
     rcu_read_lock();
 seq_ops->next():
     rcu_read_unlock();
     /* next element */
     rcu_read_lock();
 seq_ops->stop();
     rcu_read_unlock();

Compared to old bucket_lock mechanism, if concurrent updata/delete happens,
we may visit stale elements, miss some elements, or repeat some elements.
I think this is a reasonable compromise. For users wanting to avoid
stale, missing/repeated accesses, bpf_map batch access syscall interface
can be used.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200902235340.2001375-1-yhs@fb.com
2020-09-03 17:36:41 -07:00
peterz@infradead.org
23870f1227 locking/lockdep: Fix "USED" <- "IN-NMI" inversions
During the LPC RCU BoF Paul asked how come the "USED" <- "IN-NMI"
detector doesn't trip over rcu_read_lock()'s lockdep annotation.

Looking into this I found a very embarrasing typo in
verify_lock_unused():

	-	if (!(class->usage_mask & LOCK_USED))
	+	if (!(class->usage_mask & LOCKF_USED))

fixing that will indeed cause rcu_read_lock() to insta-splat :/

The above typo means that instead of testing for: 0x100 (1 <<
LOCK_USED), we test for 8 (LOCK_USED), which corresponds to (1 <<
LOCK_ENABLED_HARDIRQ).

So instead of testing for _any_ used lock, it will only match any lock
used with interrupts enabled.

The rcu_read_lock() annotation uses .check=0, which means it will not
set any of the interrupt bits and will thus never match.

In order to properly fix the situation and allow rcu_read_lock() to
correctly work, split LOCK_USED into LOCK_USED and LOCK_USED_READ and by
having .read users set USED_READ and test USED, pure read-recursive
locks are permitted.

Fixes: f6f48e1804 ("lockdep: Teach lockdep about "USED" <- "IN-NMI" inversions")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20200902160323.GK1362448@hirez.programming.kicks-ass.net
2020-09-03 11:19:42 +02:00
Yonghong Song
203d7b054f bpf: Avoid iterating duplicated files for task_file iterator
Currently, task_file iterator iterates all files from all tasks.
This may potentially visit a lot of duplicated files if there are
many tasks sharing the same files, e.g., typical pthreads
where these pthreads and the main thread are sharing the same files.

This patch changed task_file iterator to skip a particular task
if that task shares the same files as its group_leader (the task
having the same tgid and also task->tgid == task->pid).
This will preserve the same result, visiting all files from all
tasks, and will reduce runtime cost significantl, e.g., if there are
a lot of pthreads and the process has a lot of open files.

Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/bpf/20200902023112.1672792-1-yhs@fb.com
2020-09-02 16:40:33 +02:00
David S. Miller
150f29f5e6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-09-01

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

There are two small conflicts when pulling, resolve as follows:

1) Merge conflict in tools/lib/bpf/libbpf.c between 88a8212028 ("libbpf: Factor
   out common ELF operations and improve logging") in bpf-next and 1e891e513e
   ("libbpf: Fix map index used in error message") in net-next. Resolve by taking
   the hunk in bpf-next:

        [...]
        scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx);
        data = elf_sec_data(obj, scn);
        if (!scn || !data) {
                pr_warn("elf: failed to get %s map definitions for %s\n",
                        MAPS_ELF_SEC, obj->path);
                return -EINVAL;
        }
        [...]

2) Merge conflict in drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c between
   9647c57b11 ("xsk: i40e: ice: ixgbe: mlx5: Test for dma_need_sync earlier for
   better performance") in bpf-next and e20f0dbf20 ("net/mlx5e: RX, Add a prefetch
   command for small L1_CACHE_BYTES") in net-next. Resolve the two locations by retaining
   net_prefetch() and taking xsk_buff_dma_sync_for_cpu() from bpf-next. Should look like:

        [...]
        xdp_set_data_meta_invalid(xdp);
        xsk_buff_dma_sync_for_cpu(xdp, rq->xsk_pool);
        net_prefetch(xdp->data);
        [...]

We've added 133 non-merge commits during the last 14 day(s) which contain
a total of 246 files changed, 13832 insertions(+), 3105 deletions(-).

The main changes are:

1) Initial support for sleepable BPF programs along with bpf_copy_from_user() helper
   for tracing to reliably access user memory, from Alexei Starovoitov.

2) Add BPF infra for writing and parsing TCP header options, from Martin KaFai Lau.

3) bpf_d_path() helper for returning full path for given 'struct path', from Jiri Olsa.

4) AF_XDP support for shared umems between devices and queues, from Magnus Karlsson.

5) Initial prep work for full BPF-to-BPF call support in libbpf, from Andrii Nakryiko.

6) Generalize bpf_sk_storage map & add local storage for inodes, from KP Singh.

7) Implement sockmap/hash updates from BPF context, from Lorenz Bauer.

8) BPF xor verification for scalar types & add BPF link iterator, from Yonghong Song.

9) Use target's prog type for BPF_PROG_TYPE_EXT prog verification, from Udip Pant.

10) Rework BPF tracing samples to use libbpf loader, from Daniel T. Lee.

11) Fix xdpsock sample to really cycle through all buffers, from Weqaar Janjua.

12) Improve type safety for tun/veth XDP frame handling, from Maciej Żenczykowski.

13) Various smaller cleanups and improvements all over the place.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-01 13:22:59 -07:00
Björn Töpel
ebc4ecd48c bpf: {cpu,dev}map: Change various functions return type from int to void
The functions bq_enqueue(), bq_flush_to_queue(), and bq_xmit_all() in
{cpu,dev}map.c always return zero. Changing the return type from int
to void makes the code easier to follow.

Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200901083928.6199-1-bjorn.topel@gmail.com
2020-09-01 15:45:58 +02:00
Alexei Starovoitov
f56407fa6e bpf: Remove bpf_lsm_file_mprotect from sleepable list.
Technically the bpf programs can sleep while attached to bpf_lsm_file_mprotect,
but such programs need to access user memory. So they're in might_fault()
category. Which means they cannot be called from file_mprotect lsm hook that
takes write lock on mm->mmap_lock.
Adjust the test accordingly.

Also add might_fault() to __bpf_prog_enter_sleepable() to catch such deadlocks early.

Fixes: 1e6c62a882 ("bpf: Introduce sleepable BPF programs")
Fixes: e68a144547 ("selftests/bpf: Add sleepable tests")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200831201651.82447-1-alexei.starovoitov@gmail.com
2020-08-31 23:03:57 +02:00
Alexei Starovoitov
29523c5e67 bpf: Fix build without BPF_LSM.
resolve_btfids doesn't like empty set. Add unused ID when BPF_LSM is off.

Fixes: 1e6c62a882 ("bpf: Introduce sleepable BPF programs")
Reported-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Song Liu <songliubraving@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200831163132.66521-1-alexei.starovoitov@gmail.com
2020-08-31 20:56:10 +02:00
Linus Torvalds
dcc5c6f013 Merge tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "Three interrupt related fixes for X86:

   - Move disabling of the local APIC after invoking fixup_irqs() to
     ensure that interrupts which are incoming are noted in the IRR and
     not ignored.

   - Unbreak affinity setting.

     The rework of the entry code reused the regular exception entry
     code for device interrupts. The vector number is pushed into the
     errorcode slot on the stack which is then lifted into an argument
     and set to -1 because that's regs->orig_ax which is used in quite
     some places to check whether the entry came from a syscall.

     But it was overlooked that orig_ax is used in the affinity cleanup
     code to validate whether the interrupt has arrived on the new
     target. It turned out that this vector check is pointless because
     interrupts are never moved from one vector to another on the same
     CPU. That check is a historical leftover from the time where x86
     supported multi-CPU affinities, but not longer needed with the now
     strict single CPU affinity. Famous last words ...

   - Add a missing check for an empty cpumask into the matrix allocator.

     The affinity change added a warning to catch the case where an
     interrupt is moved on the same CPU to a different vector. This
     triggers because a condition with an empty cpumask returns an
     assignment from the allocator as the allocator uses for_each_cpu()
     without checking the cpumask for being empty. The historical
     inconsistent for_each_cpu() behaviour of ignoring the cpumask and
     unconditionally claiming that CPU0 is in the mask struck again.
     Sigh.

  plus a new entry into the MAINTAINER file for the HPE/UV platform"

* tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/matrix: Deal with the sillyness of for_each_cpu() on UP
  x86/irq: Unbreak interrupt affinity setting
  x86/hotplug: Silence APIC only after all interrupts are migrated
  MAINTAINERS: Add entry for HPE Superdome Flex (UV) maintainers
2020-08-30 12:01:23 -07:00
Linus Torvalds
b69bea8a65 Merge tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "A set of fixes for lockdep, tracing and RCU:

   - Prevent recursion by using raw_cpu_* operations

   - Fixup the interrupt state in the cpu idle code to be consistent

   - Push rcu_idle_enter/exit() invocations deeper into the idle path so
     that the lock operations are inside the RCU watching sections

   - Move trace_cpu_idle() into generic code so it's called before RCU
     goes idle.

   - Handle raw_local_irq* vs. local_irq* operations correctly

   - Move the tracepoints out from under the lockdep recursion handling
     which turned out to be fragile and inconsistent"

* tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep,trace: Expose tracepoints
  lockdep: Only trace IRQ edges
  mips: Implement arch_irqs_disabled()
  arm64: Implement arch_irqs_disabled()
  nds32: Implement arch_irqs_disabled()
  locking/lockdep: Cleanup
  x86/entry: Remove unused THUNKs
  cpuidle: Move trace_cpu_idle() into generic code
  cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic
  sched,idle,rcu: Push rcu_idle deeper into the idle path
  cpuidle: Fixup IRQ state
  lockdep: Use raw_cpu_*() for per-cpu variables
2020-08-30 11:43:50 -07:00
Thomas Gleixner
784a083037 genirq/matrix: Deal with the sillyness of for_each_cpu() on UP
Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.

The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027fffff7 ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.

Add a check for the cpumask being empty to prevent this.

Fixes: 2f75d9e1c9 ("genirq: Implement bitmap matrix allocator")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2020-08-30 19:17:28 +02:00
Alexei Starovoitov
07be4c4a3e bpf: Add bpf_copy_from_user() helper.
Sleepable BPF programs can now use copy_from_user() to access user memory.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-4-alexei.starovoitov@gmail.com
2020-08-28 21:20:33 +02:00
Alexei Starovoitov
1e6c62a882 bpf: Introduce sleepable BPF programs
Introduce sleepable BPF programs that can request such property for themselves
via BPF_F_SLEEPABLE flag at program load time. In such case they will be able
to use helpers like bpf_copy_from_user() that might sleep. At present only
fentry/fexit/fmod_ret and lsm programs can request to be sleepable and only
when they are attached to kernel functions that are known to allow sleeping.

The non-sleepable programs are relying on implicit rcu_read_lock() and
migrate_disable() to protect life time of programs, maps that they use and
per-cpu kernel structures used to pass info between bpf programs and the
kernel. The sleepable programs cannot be enclosed into rcu_read_lock().
migrate_disable() maps to preempt_disable() in non-RT kernels, so the progs
should not be enclosed in migrate_disable() as well. Therefore
rcu_read_lock_trace is used to protect the life time of sleepable progs.

There are many networking and tracing program types. In many cases the
'struct bpf_prog *' pointer itself is rcu protected within some other kernel
data structure and the kernel code is using rcu_dereference() to load that
program pointer and call BPF_PROG_RUN() on it. All these cases are not touched.
Instead sleepable bpf programs are allowed with bpf trampoline only. The
program pointers are hard-coded into generated assembly of bpf trampoline and
synchronize_rcu_tasks_trace() is used to protect the life time of the program.
The same trampoline can hold both sleepable and non-sleepable progs.

When rcu_read_lock_trace is held it means that some sleepable bpf program is
running from bpf trampoline. Those programs can use bpf arrays and preallocated
hash/lru maps. These map types are waiting on programs to complete via
synchronize_rcu_tasks_trace();

Updates to trampoline now has to do synchronize_rcu_tasks_trace() and
synchronize_rcu_tasks() to wait for sleepable progs to finish and for
trampoline assembly to finish.

This is the first step of introducing sleepable progs. Eventually dynamically
allocated hash maps can be allowed and networking program types can become
sleepable too.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-3-alexei.starovoitov@gmail.com
2020-08-28 21:20:33 +02:00
Martin KaFai Lau
134fede4ee bpf: Relax max_entries check for most of the inner map types
Most of the maps do not use max_entries during verification time.
Thus, those map_meta_equal() do not need to enforce max_entries
when it is inserted as an inner map during runtime.  The max_entries
check is removed from the default implementation bpf_map_meta_equal().

The prog_array_map and xsk_map are exception.  Its map_gen_lookup
uses max_entries to generate inline lookup code.  Thus, they will
implement its own map_meta_equal() to enforce max_entries.
Since there are only two cases now, the max_entries check
is not refactored and stays in its own .c file.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200828011813.1970516-1-kafai@fb.com
2020-08-28 15:41:30 +02:00
Martin KaFai Lau
f4d0525921 bpf: Add map_meta_equal map ops
Some properties of the inner map is used in the verification time.
When an inner map is inserted to an outer map at runtime,
bpf_map_meta_equal() is currently used to ensure those properties
of the inserting inner map stays the same as the verification
time.

In particular, the current bpf_map_meta_equal() checks max_entries which
turns out to be too restrictive for most of the maps which do not use
max_entries during the verification time.  It limits the use case that
wants to replace a smaller inner map with a larger inner map.  There are
some maps do use max_entries during verification though.  For example,
the map_gen_lookup in array_map_ops uses the max_entries to generate
the inline lookup code.

To accommodate differences between maps, the map_meta_equal is added
to bpf_map_ops.  Each map-type can decide what to check when its
map is used as an inner map during runtime.

Also, some map types cannot be used as an inner map and they are
currently black listed in bpf_map_meta_alloc() in map_in_map.c.
It is not unusual that the new map types may not aware that such
blacklist exists.  This patch enforces an explicit opt-in
and only allows a map to be used as an inner map if it has
implemented the map_meta_equal ops.  It is based on the
discussion in [1].

All maps that support inner map has its map_meta_equal points
to bpf_map_meta_equal in this patch.  A later patch will
relax the max_entries check for most maps.  bpf_types.h
counts 28 map types.  This patch adds 23 ".map_meta_equal"
by using coccinelle.  -5 for
	BPF_MAP_TYPE_PROG_ARRAY
	BPF_MAP_TYPE_(PERCPU)_CGROUP_STORAGE
	BPF_MAP_TYPE_STRUCT_OPS
	BPF_MAP_TYPE_ARRAY_OF_MAPS
	BPF_MAP_TYPE_HASH_OF_MAPS

The "if (inner_map->inner_map_meta)" check in bpf_map_meta_alloc()
is moved such that the same error is returned.

[1]: https://lore.kernel.org/bpf/20200522022342.899756-1-kafai@fb.com/

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200828011806.1970400-1-kafai@fb.com
2020-08-28 15:41:30 +02:00
Dan Carpenter
892fc9f683 dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()
The "page" pointer can be used with out being initialized.

Fixes: d7e673ec2c ("dma-pool: Only allocate from CMA when in same memory zone")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-27 09:22:56 +02:00
Yonghong Song
2921c90d47 bpf: Fix a verifier failure with xor
bpf selftest test_progs/test_sk_assign failed with llvm 11 and llvm 12.
Compared to llvm 10, llvm 11 and 12 generates xor instruction which
is not handled properly in verifier. The following illustrates the
problem:

  16: (b4) w5 = 0
  17: ... R5_w=inv0 ...
  ...
  132: (a4) w5 ^= 1
  133: ... R5_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ...
  ...
  37: (bc) w8 = w5
  38: ... R5=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
          R8_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ...
  ...
  41: (bc) w3 = w8
  42: ... R3_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ...
  45: (56) if w3 != 0x0 goto pc+1
   ... R3_w=inv0 ...
  46: (b7) r1 = 34
  47: R1_w=inv34 R7=pkt(id=0,off=26,r=38,imm=0)
  47: (0f) r7 += r1
  48: R1_w=invP34 R3_w=inv0 R7_w=pkt(id=0,off=60,r=38,imm=0)
  48: (b4) w9 = 0
  49: R1_w=invP34 R3_w=inv0 R7_w=pkt(id=0,off=60,r=38,imm=0)
  49: (69) r1 = *(u16 *)(r7 +0)
  invalid access to packet, off=60 size=2, R7(id=0,off=60,r=38)
  R7 offset is outside of the packet

At above insn 132, w5 = 0, but after w5 ^= 1, we give a really conservative
value of w5. At insn 45, in reality the condition should be always false.
But due to conservative value for w3, the verifier evaluates it could be
true and this later leads to verifier failure complaining potential
packet out-of-bound access.

This patch implemented proper XOR support in verifier.
In the above example, we have:
  132: R5=invP0
  132: (a4) w5 ^= 1
  133: R5_w=invP1
  ...
  37: (bc) w8 = w5
  ...
  41: (bc) w3 = w8
  42: R3_w=invP1
  ...
  45: (56) if w3 != 0x0 goto pc+1
  47: R3_w=invP1
  ...
  processed 353 insns ...
and the verifier can verify the program successfully.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200825064608.2017937-1-yhs@fb.com
2020-08-26 21:47:32 -07:00
Udip Pant
7e40781cc8 bpf: verifier: Use target program's type for access verifications
This patch adds changes in verifier to make decisions such as granting
of read / write access or enforcement of return code status based on
the program type of the target program while using dynamic program
extension (of type BPF_PROG_TYPE_EXT).

The BPF_PROG_TYPE_EXT type can be used to extend types such as XDP, SKB
and others. Since the BPF_PROG_TYPE_EXT program type on itself is just a
placeholder for those, we need this extended check for those extended
programs to actually work with proper access, while using this option.

Specifically, it introduces following changes:
- may_access_direct_pkt_data:
    allow access to packet data based on the target prog
- check_return_code:
    enforce return code based on the target prog
    (currently, this check is skipped for EXT program)
- check_ld_abs:
    check for 'may_access_skb' based on the target prog
- check_map_prog_compatibility:
    enforce the map compatibility check based on the target prog
- may_update_sockmap:
    allow sockmap update based on the target prog

Some other occurrences of prog->type is left as it without replacing
with the 'resolved' type:
- do_check_common() and check_attach_btf_id():
    already have specific logic to handle the EXT prog type
- jit_subprogs() and bpf_check():
    Not changed for jit compilation or while inferring env->ops

Next few patches in this series include selftests for some of these cases.

Signed-off-by: Udip Pant <udippant@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200825232003.2877030-2-udippant@fb.com
2020-08-26 12:47:56 -07:00
Peter Zijlstra
eb1f00237a lockdep,trace: Expose tracepoints
The lockdep tracepoints are under the lockdep recursion counter, this
has a bunch of nasty side effects:

 - TRACE_IRQFLAGS doesn't work across the entire tracepoint

 - RCU-lockdep doesn't see the tracepoints either, hiding numerous
   "suspicious RCU usage" warnings.

Pull the trace_lock_*() tracepoints completely out from under the
lockdep recursion handling and completely rely on the trace level
recusion handling -- also, tracing *SHOULD* not be taking locks in any
case.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.782688941@infradead.org
2020-08-26 12:41:56 +02:00
Peter Zijlstra
9864f5b594 cpuidle: Move trace_cpu_idle() into generic code
Remove trace_cpu_idle() from the arch_cpu_idle() implementations and
put it in the generic code, right before disabling RCU. Gets rid of
more trace_*_rcuidle() users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.428433395@infradead.org
2020-08-26 12:41:54 +02:00
Peter Zijlstra
1098582a0f sched,idle,rcu: Push rcu_idle deeper into the idle path
Lots of things take locks, due to a wee bug, rcu_lockdep didn't notice
that the locking tracepoints were using RCU.

Push rcu_idle_{enter,exit}() as deep as possible into the idle paths,
this also resolves a lot of _rcuidle()/RCU_NONIDLE() usage.

Specifically, sched_clock_idle_wakeup_event() will use ktime which
will use seqlocks which will tickle lockdep, and
stop_critical_timings() uses lock.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.310943801@infradead.org
2020-08-26 12:41:53 +02:00
Peter Zijlstra
fddf9055a6 lockdep: Use raw_cpu_*() for per-cpu variables
Sven reported that commit a21ee6055c ("lockdep: Change
hardirq{s_enabled,_context} to per-cpu variables") caused trouble on
s390 because their this_cpu_*() primitives disable preemption which
then lands back tracing.

On the one hand, per-cpu ops should use preempt_*able_notrace() and
raw_local_irq_*(), on the other hand, we can trivialy use raw_cpu_*()
ops for this.

Fixes: a21ee6055c ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables")
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200821085348.192346882@infradead.org
2020-08-26 12:41:53 +02:00
Jiri Olsa
6e22ab9da7 bpf: Add d_path helper
Adding d_path helper function that returns full path for
given 'struct path' object, which needs to be the kernel
BTF 'path' object. The path is returned in buffer provided
'buf' of size 'sz' and is zero terminated.

  bpf_d_path(&file->f_path, buf, size);

The helper calls directly d_path function, so there's only
limited set of function it can be called from. Adding just
very modest set for the start.

Updating also bpf.h tools uapi header and adding 'path' to
bpf_helpers_doc.py script.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-11-jolsa@kernel.org
2020-08-25 15:41:15 -07:00
Jiri Olsa
eae2e83e62 bpf: Add BTF_SET_START/END macros
Adding support to define sorted set of BTF ID values.

Following defines sorted set of BTF ID values:

  BTF_SET_START(btf_allowlist_d_path)
  BTF_ID(func, vfs_truncate)
  BTF_ID(func, vfs_fallocate)
  BTF_ID(func, dentry_open)
  BTF_ID(func, vfs_getattr)
  BTF_ID(func, filp_close)
  BTF_SET_END(btf_allowlist_d_path)

It defines following 'struct btf_id_set' variable to access
values and count:

  struct btf_id_set btf_allowlist_d_path;

Adding 'allowed' callback to struct bpf_func_proto, to allow
verifier the check on allowed callers.

Adding btf_id_set_contains function, which will be used by
allowed callbacks to verify the caller's BTF ID value is
within allowed set.

Also removing extra '\' in __BTF_ID_LIST macro.

Added BTF_SET_START_GLOBAL macro for global sets.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-10-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Jiri Olsa
faaf4a790d bpf: Add btf_struct_ids_match function
Adding btf_struct_ids_match function to check if given address provided
by BTF object + offset is also address of another nested BTF object.

This allows to pass an argument to helper, which is defined via parent
BTF object + offset, like for bpf_d_path (added in following changes):

  SEC("fentry/filp_close")
  int BPF_PROG(prog_close, struct file *file, void *id)
  {
    ...
    ret = bpf_d_path(&file->f_path, ...

The first bpf_d_path argument is hold by verifier as BTF file object
plus offset of f_path member.

The btf_struct_ids_match function will walk the struct file object and
check if there's nested struct path object on the given offset.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-9-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Jiri Olsa
1c6d28a6ac bpf: Factor btf_struct_access function
Adding btf_struct_walk function that walks through the
struct type + given offset and returns following values:

  enum bpf_struct_walk_result {
       /* < 0 error */
       WALK_SCALAR = 0,
       WALK_PTR,
       WALK_STRUCT,
  };

WALK_SCALAR - when SCALAR_VALUE is found
WALK_PTR    - when pointer value is found, its ID is stored
              in 'next_btf_id' output param
WALK_STRUCT - when nested struct object is found, its ID is stored
              in 'next_btf_id' output param

It will be used in following patches to get all nested
struct objects for given type and offset.

The btf_struct_access now calls btf_struct_walk function,
as long as it gets nested structs as return value.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-8-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Jiri Olsa
dafe58fc19 bpf: Remove recursion call in btf_struct_access
Andrii suggested we can simply jump to again label
instead of making recursion call.

Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-7-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Jiri Olsa
887c31a39c bpf: Add type_id pointer as argument to __btf_resolve_size
Adding type_id pointer as argument to __btf_resolve_size
to return also BTF ID of the resolved type. It will be
used in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-6-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Jiri Olsa
69ff304792 bpf: Add elem_id pointer as argument to __btf_resolve_size
If the resolved type is array, make btf_resolve_size return also
ID of the elem type. It will be needed in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-5-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Jiri Olsa
6298399bfc bpf: Move btf_resolve_size into __btf_resolve_size
Moving btf_resolve_size into __btf_resolve_size and
keeping btf_resolve_size public with just first 3
arguments, because the rest of the arguments are not
used by outside callers.

Following changes are adding more arguments, which
are not useful to outside callers. They will be added
to the __btf_resolve_size function.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-4-jolsa@kernel.org
2020-08-25 15:37:41 -07:00
Alexei Starovoitov
2532f849b5 bpf: Disallow BPF_PRELOAD in allmodconfig builds
The CC_CAN_LINK checks that the host compiler can link, but bpf_preload
relies on libbpf which in turn needs libelf to be present during linking.
allmodconfig runs in odd setups with cross compilers and missing host
libraries like libelf. Instead of extending kconfig with every possible
library that bpf_preload might need disallow building BPF_PRELOAD in
such build-only configurations.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-08-25 15:23:46 -07:00
KP Singh
30897832d8 bpf: Allow local storage to be used from LSM programs
Adds support for both bpf_{sk, inode}_storage_{get, delete} to be used
in LSM programs. These helpers are not used for tracing programs
(currently) as their usage is tied to the life-cycle of the object and
should only be used where the owning object won't be freed (when the
owning object is passed as an argument to the LSM hook). Thus, they
are safer to use in LSM hooks than tracing. Usage of local storage in
tracing programs will probably follow a per function based whitelist
approach.

Since the UAPI helper signature for bpf_sk_storage expect a bpf_sock,
it, leads to a compilation warning for LSM programs, it's also updated
to accept a void * pointer instead.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-7-kpsingh@chromium.org
2020-08-25 15:00:04 -07:00
KP Singh
8ea636848a bpf: Implement bpf_local_storage for inodes
Similar to bpf_local_storage for sockets, add local storage for inodes.
The life-cycle of storage is managed with the life-cycle of the inode.
i.e. the storage is destroyed along with the owning inode.

The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the
security blob which are now stackable and can co-exist with other LSMs.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-6-kpsingh@chromium.org
2020-08-25 15:00:04 -07:00
KP Singh
450af8d0f6 bpf: Split bpf_local_storage to bpf_sk_storage
A purely mechanical change:

	bpf_sk_storage.c = bpf_sk_storage.c + bpf_local_storage.c
	bpf_sk_storage.h = bpf_sk_storage.h + bpf_local_storage.h

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-5-kpsingh@chromium.org
2020-08-25 15:00:04 -07:00
Tobias Klauser
7787b6fc93 bpf, sysctl: Let bpf_stats_handler take a kernel pointer buffer
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer. Adjust the
signature of bpf_stats_handler to match ctl_table.proc_handler which
fixes the following sparse warning:

kernel/sysctl.c:226:49: warning: incorrect type in argument 3 (different address spaces)
kernel/sysctl.c:226:49:    expected void *
kernel/sysctl.c:226:49:    got void [noderef] __user *buffer
kernel/sysctl.c:2640:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
kernel/sysctl.c:2640:35:    expected int ( [usertype] *proc_handler )( ... )
kernel/sysctl.c:2640:35:    got int ( * )( ... )

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20200824142047.22043-1-tklauser@distanz.ch
2020-08-24 21:11:40 -07:00
Yonghong Song
b474959d5a bpf: Fix a buffer out-of-bound access when filling raw_tp link_info
Commit f2e10bff16 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link")
added link query for raw_tp. One of fields in link_info is to
fill a user buffer with tp_name. The Scurrent checking only
declares "ulen && !ubuf" as invalid. So "!ulen && ubuf" will be
valid. Later on, we do "copy_to_user(ubuf, tp_name, ulen - 1)" which
may overwrite user memory incorrectly.

This patch fixed the problem by disallowing "!ulen && ubuf" case as well.

Fixes: f2e10bff16 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200821191054.714731-1-yhs@fb.com
2020-08-24 21:03:07 -07:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Linus Torvalds
e99b2507ba Merge tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull entry fix from Thomas Gleixner:
 "A single bug fix for the common entry code.

  The transcription of the x86 version messed up the reload of the
  syscall number from pt_regs after ptrace and seccomp which breaks
  syscall number rewriting"

* tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  core/entry: Respect syscall number rewrites
2020-08-23 11:05:47 -07:00
Linus Torvalds
9d045ed1eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "Nothing earth shattering here, lots of small fixes (f.e. missing RCU
  protection, bad ref counting, missing memset(), etc.) all over the
  place:

   1) Use get_file_rcu() in task_file iterator, from Yonghong Song.

   2) There are two ways to set remote source MAC addresses in macvlan
      driver, but only one of which validates things properly. Fix this.
      From Alvin Šipraga.

   3) Missing of_node_put() in gianfar probing, from Sumera
      Priyadarsini.

   4) Preserve device wanted feature bits across multiple netlink
      ethtool requests, from Maxim Mikityanskiy.

   5) Fix rcu_sched stall in task and task_file bpf iterators, from
      Yonghong Song.

   6) Avoid reset after device destroy in ena driver, from Shay
      Agroskin.

   7) Missing memset() in netlink policy export reallocation path, from
      Johannes Berg.

   8) Fix info leak in __smc_diag_dump(), from Peilin Ye.

   9) Decapsulate ECN properly for ipv6 in ipv4 tunnels, from Mark
      Tomlinson.

  10) Fix number of data stream negotiation in SCTP, from David Laight.

  11) Fix double free in connection tracker action module, from Alaa
      Hleihel.

  12) Don't allow empty NHA_GROUP attributes, from Nikolay Aleksandrov"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (46 commits)
  net: nexthop: don't allow empty NHA_GROUP
  bpf: Fix two typos in uapi/linux/bpf.h
  net: dsa: b53: check for timeout
  tipc: call rcu_read_lock() in tipc_aead_encrypt_done()
  net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow
  net: sctp: Fix negotiation of the number of data streams.
  dt-bindings: net: renesas, ether: Improve schema validation
  gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY
  hv_netvsc: Fix the queue_mapping in netvsc_vf_xmit()
  hv_netvsc: Remove "unlikely" from netvsc_select_queue
  bpf: selftests: global_funcs: Check err_str before strstr
  bpf: xdp: Fix XDP mode when no mode flags specified
  selftests/bpf: Remove test_align leftovers
  tools/resolve_btfids: Fix sections with wrong alignment
  net/smc: Prevent kernel-infoleak in __smc_diag_dump()
  sfc: fix build warnings on 32-bit
  net: phy: mscc: Fix a couple of spelling mistakes "spcified" -> "specified"
  libbpf: Fix map index used in error message
  net: gemini: Fix missing free_netdev() in error path of gemini_ethernet_port_probe()
  net: atlantic: Use readx_poll_timeout() for large timeout
  ...
2020-08-23 10:52:33 -07:00