| Commit message (Collapse) | Author | Age | Files | Lines |
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Merge updates from Andrew Morton:
"A large amount of MM, plenty more to come.
Subsystems affected by this patch series:
- tools
- kthread
- kbuild
- scripts
- ocfs2
- vfs
- mm: slub, kmemleak, pagecache, gup, swap, memcg, pagemap, mremap,
sparsemem, kasan, pagealloc, vmscan, compaction, mempolicy,
hugetlbfs, hugetlb"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits)
include/linux/huge_mm.h: check PageTail in hpage_nr_pages even when !THP
mm/hugetlb: fix build failure with HUGETLB_PAGE but not HUGEBTLBFS
selftests/vm: fix map_hugetlb length used for testing read and write
mm/hugetlb: remove unnecessary memory fetch in PageHeadHuge()
mm/hugetlb.c: clean code by removing unnecessary initialization
hugetlb_cgroup: add hugetlb_cgroup reservation docs
hugetlb_cgroup: add hugetlb_cgroup reservation tests
hugetlb: support file_region coalescing again
hugetlb_cgroup: support noreserve mappings
hugetlb_cgroup: add accounting for shared mappings
hugetlb: disable region_add file_region coalescing
hugetlb_cgroup: add reservation accounting for private mappings
mm/hugetlb_cgroup: fix hugetlb_cgroup migration
hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations
hugetlb_cgroup: add hugetlb_cgroup reservation counter
hugetlbfs: Use i_mmap_rwsem to address page fault/truncate race
hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
mm/memblock.c: remove redundant assignment to variable max_addr
mm: mempolicy: require at least one nodeid for MPOL_PREFERRED
mm: mempolicy: use VM_BUG_ON_VMA in queue_pages_test_walk()
...
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Since commit 5bbe3547aa3ba ("mm: allow compaction of unevictable pages")
it is allowed to examine mlocked pages and compact them by default. On
-RT even minor pagefaults are problematic because it may take a few 100us
to resolve them and until then the task is blocked.
Make compact_unevictable_allowed = 0 default and issue a warning on RT if
it is changed.
[bigeasy@linutronix.de: v5]
Link: https://lore.kernel.org/linux-mm/20190710144138.qyn4tuttdq6h7kqx@linutronix.de/
Link: http://lkml.kernel.org/r/20200319165536.ovi75tsr2seared4@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/linux-mm/20190710144138.qyn4tuttdq6h7kqx@linutronix.de/
Link: http://lkml.kernel.org/r/20200303202225.nhqc3v5gwlb7x6et@linutronix.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The proc file `compact_unevictable_allowed' should allow 0 and 1 only, the
`extra*' attribues have been set properly but without
proc_dointvec_minmax() as the `proc_handler' the limit will not be
enforced.
Use proc_dointvec_minmax() as the `proc_handler' to enfoce the valid
specified range.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Link: http://lkml.kernel.org/r/20200303202054.gsosv7fsx2ma3cic@linutronix.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Right now, the effective protection of any given cgroup is capped by its
own explicit memory.low setting, regardless of what the parent says. The
reasons for this are mostly historical and ease of implementation: to make
delegation of memory.low safe, effective protection is the min() of all
memory.low up the tree.
Unfortunately, this limitation makes it impossible to protect an entire
subtree from another without forcing the user to make explicit protection
allocations all the way to the leaf cgroups - something that is highly
undesirable in real life scenarios.
Consider memory in a data center host. At the cgroup top level, we have a
distinction between system management software and the actual workload the
system is executing. Both branches are further subdivided into individual
services, job components etc.
We want to protect the workload as a whole from the system management
software, but that doesn't mean we want to protect and prioritize
individual workload wrt each other. Their memory demand can vary over
time, and we'd want the VM to simply cache the hottest data within the
workload subtree. Yet, the current memory.low limitations force us to
allocate a fixed amount of protection to each workload component in order
to get protection from system management software in general. This
results in very inefficient resource distribution.
Another concern with mandating downward allocation is that, as the
complexity of the cgroup tree grows, it gets harder for the lower levels
to be informed about decisions made at the host-level. Consider a
container inside a namespace that in turn creates its own nested tree of
cgroups to run multiple workloads. It'd be extremely difficult to
configure memory.low parameters in those leaf cgroups that on one hand
balance pressure among siblings as the container desires, while also
reflecting the host-level protection from e.g. rpm upgrades, that lie
beyond one or more delegation and namespacing points in the tree.
It's highly unusual from a cgroup interface POV that nested levels have to
be aware of and reflect decisions made at higher levels for them to be
effective.
To enable such use cases and scale configurability for complex trees, this
patch implements a resource inheritance model for memory that is similar
to how the CPU and the IO controller implement work-conserving resource
allocations: a share of a resource allocated to a subree always applies to
the entire subtree recursively, while allowing, but not mandating,
children to further specify distribution rules.
That means that if protection is explicitly allocated among siblings,
those configured shares are being followed during page reclaim just like
they are now. However, if the memory.low set at a higher level is not
fully claimed by the children in that subtree, the "floating" remainder is
applied to each cgroup in the tree in proportion to its size. Since
reclaim pressure is applied in proportion to size as well, each child in
that tree gets the same boost, and the effect is neutral among siblings -
with respect to each other, they behave as if no memory control was
enabled at all, and the VM simply balances the memory demands optimally
within the subtree. But collectively those cgroups enjoy a boost over the
cgroups in neighboring trees.
E.g. a leaf cgroup with a memory.low setting of 0 no longer means that
it's not getting a share of the hierarchically assigned resource, just
that it doesn't claim a fixed amount of it to protect from its siblings.
This allows us to recursively protect one subtree (workload) from another
(system management), while letting subgroups compete freely among each
other - without having to assign fixed shares to each leaf, and without
nested groups having to echo higher-level settings.
The floating protection composes naturally with fixed protection.
Consider the following example tree:
A A: low = 2G
/ \ A1: low = 1G
A1 A2 A2: low = 0G
As outside pressure is applied to this tree, A1 will enjoy a fixed
protection from A2 of 1G, but the remaining, unclaimed 1G from A is split
evenly among A1 and A2, coming out to 1.5G and 0.5G.
There is a slight risk of regressing theoretical setups where the
top-level cgroups don't know about the true budgeting and set bogusly high
"bypass" values that are meaningfully allocated down the tree. Such
setups would rely on unclaimed protection to be discarded, and
distributing it would change the intended behavior. Be safe and hide the
new behavior behind a mount option, 'memory_recursiveprot'.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Link: http://lkml.kernel.org/r/20200227195606.46212-4-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Rename (__)memcg_kmem_(un)charge() into (__)memcg_kmem_(un)charge_page()
to better reflect what they are actually doing:
1) call __memcg_kmem_(un)charge_memcg() to actually charge or uncharge
the current memcg
2) set or clear the PageKmemcg flag
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: http://lkml.kernel.org/r/20200109202659.752357-4-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull exec/proc updates from Eric Biederman:
"This contains two significant pieces of work: the work to sort out
proc_flush_task, and the work to solve a deadlock between strace and
exec.
Fixing proc_flush_task so that it no longer requires a persistent
mount makes improvements to proc possible. The removal of the
persistent mount solves an old regression that that caused the hidepid
mount option to only work on remount not on mount. The regression was
found and reported by the Android folks. This further allows Alexey
Gladkov's work making proc mount options specific to an individual
mount of proc to move forward.
The work on exec starts solving a long standing issue with exec that
it takes mutexes of blocking userspace applications, which makes exec
extremely deadlock prone. For the moment this adds a second mutex with
a narrower scope that handles all of the easy cases. Which makes the
tricky cases easy to spot. With a little luck the code to solve those
deadlocks will be ready by next merge window"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (25 commits)
signal: Extend exec_id to 64bits
pidfd: Use new infrastructure to fix deadlocks in execve
perf: Use new infrastructure to fix deadlocks in execve
proc: io_accounting: Use new infrastructure to fix deadlocks in execve
proc: Use new infrastructure to fix deadlocks in execve
kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve
kernel: doc: remove outdated comment cred.c
mm: docs: Fix a comment in process_vm_rw_core
selftests/ptrace: add test cases for dead-locks
exec: Fix a deadlock in strace
exec: Add exec_update_mutex to replace cred_guard_mutex
exec: Move exec_mmap right after de_thread in flush_old_exec
exec: Move cleanup of posix timers on exec out of de_thread
exec: Factor unshare_sighand out of de_thread and call it separately
exec: Only compute current once in flush_old_exec
pid: Improve the comment about waiting in zap_pid_ns_processes
proc: Remove the now unnecessary internal mount of proc
uml: Create a private mount of proc for mconsole
uml: Don't consult current to find the proc_mnt in mconsole_proc
proc: Use a list of inodes to flush from proc
...
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Replace the 32bit exec_id with a 64bit exec_id to make it impossible
to wrap the exec_id counter. With care an attacker can cause exec_id
wrap and send arbitrary signals to a newly exec'd parent. This
bypasses the signal sending checks if the parent changes their
credentials during exec.
The severity of this problem can been seen that in my limited testing
of a 32bit exec_id it can take as little as 19s to exec 65536 times.
Which means that it can take as little as 14 days to wrap a 32bit
exec_id. Adam Zabrocki has succeeded wrapping the self_exe_id in 7
days. Even my slower timing is in the uptime of a typical server.
Which means self_exec_id is simply a speed bump today, and if exec
gets noticably faster self_exec_id won't even be a speed bump.
Extending self_exec_id to 64bits introduces a problem on 32bit
architectures where reading self_exec_id is no longer atomic and can
take two read instructions. Which means that is is possible to hit
a window where the read value of exec_id does not match the written
value. So with very lucky timing after this change this still
remains expoiltable.
I have updated the update of exec_id on exec to use WRITE_ONCE
and the read of exec_id in do_notify_parent to use READ_ONCE
to make it clear that there is no locking between these two
locations.
Link: https://lore.kernel.org/kernel-hardening/20200324215049.GA3710@pi3.com.pl
Fixes: 2.3.23pre2
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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This changes __pidfd_fget to use the new exec_update_mutex
instead of cred_guard_mutex.
This should be safe, as the credentials do not change
before exec_update_mutex is locked. Therefore whatever
file access is possible with holding the cred_guard_mutex
here is also possbile with the exec_update_mutex.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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This changes perf_event_set_clock to use the new exec_update_mutex
instead of cred_guard_mutex.
This should be safe, as the credentials are only used for reading.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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This changes kcmp_epoll_target to use the new exec_update_mutex
instead of cred_guard_mutex.
This should be safe, as the credentials are only used for reading,
and furthermore ->mm and ->sighand are updated on execve,
but only under the new exec_update_mutex.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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This removes an outdated comment in prepare_kernel_cred.
There is no "cred_replace_mutex" any more, so the comment must
go away.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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This fixes a deadlock in the tracer when tracing a multi-threaded
application that calls execve while more than one thread are running.
I observed that when running strace on the gcc test suite, it always
blocks after a while, when expect calls execve, because other threads
have to be terminated. They send ptrace events, but the strace is no
longer able to respond, since it is blocked in vm_access.
The deadlock is always happening when strace needs to access the
tracees process mmap, while another thread in the tracee starts to
execve a child process, but that cannot continue until the
PTRACE_EVENT_EXIT is handled and the WIFEXITED event is received:
strace D 0 30614 30584 0x00000000
Call Trace:
__schedule+0x3ce/0x6e0
schedule+0x5c/0xd0
schedule_preempt_disabled+0x15/0x20
__mutex_lock.isra.13+0x1ec/0x520
__mutex_lock_killable_slowpath+0x13/0x20
mutex_lock_killable+0x28/0x30
mm_access+0x27/0xa0
process_vm_rw_core.isra.3+0xff/0x550
process_vm_rw+0xdd/0xf0
__x64_sys_process_vm_readv+0x31/0x40
do_syscall_64+0x64/0x220
entry_SYSCALL_64_after_hwframe+0x44/0xa9
expect D 0 31933 30876 0x80004003
Call Trace:
__schedule+0x3ce/0x6e0
schedule+0x5c/0xd0
flush_old_exec+0xc4/0x770
load_elf_binary+0x35a/0x16c0
search_binary_handler+0x97/0x1d0
__do_execve_file.isra.40+0x5d4/0x8a0
__x64_sys_execve+0x49/0x60
do_syscall_64+0x64/0x220
entry_SYSCALL_64_after_hwframe+0x44/0xa9
This changes mm_access to use the new exec_update_mutex
instead of cred_guard_mutex.
This patch is based on the following patch by Eric W. Biederman:
"[PATCH 0/5] Infrastructure to allow fixing exec deadlocks"
Link: https://lore.kernel.org/lkml/87v9ne5y4y.fsf_-_@x220.int.ebiederm.org/
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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The cred_guard_mutex is problematic as it is held over possibly
indefinite waits for userspace. The possible indefinite waits for
userspace that I have identified are: The cred_guard_mutex is held in
PTRACE_EVENT_EXIT waiting for the tracer. The cred_guard_mutex is
held over "put_user(0, tsk->clear_child_tid)" in exit_mm(). The
cred_guard_mutex is held over "get_user(futex_offset, ...") in
exit_robust_list. The cred_guard_mutex held over copy_strings.
The functions get_user and put_user can trigger a page fault which can
potentially wait indefinitely in the case of userfaultfd or if
userspace implements part of the page fault path.
In any of those cases the userspace process that the kernel is waiting
for might make a different system call that winds up taking the
cred_guard_mutex and result in deadlock.
Holding a mutex over any of those possibly indefinite waits for
userspace does not appear necessary. Add exec_update_mutex that will
just cover updating the process during exec where the permissions and
the objects pointed to by the task struct may be out of sync.
The plan is to switch the users of cred_guard_mutex to
exec_update_mutex one by one. This lets us move forward while still
being careful and not introducing any regressions.
Link: https://lore.kernel.org/lkml/20160921152946.GA24210@dhcp22.suse.cz/
Link: https://lore.kernel.org/lkml/AM6PR03MB5170B06F3A2B75EFB98D071AE4E60@AM6PR03MB5170.eurprd03.prod.outlook.com/
Link: https://lore.kernel.org/linux-fsdevel/20161102181806.GB1112@redhat.com/
Link: https://lore.kernel.org/lkml/20160923095031.GA14923@redhat.com/
Link: https://lore.kernel.org/lkml/20170213141452.GA30203@redhat.com/
Ref: 45c1a159b85b ("Add PTRACE_O_TRACEVFORKDONE and PTRACE_O_TRACEEXIT facilities.")
Ref: 456f17cd1a28 ("[PATCH] user-vm-unlock-2.5.31-A2")
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Oleg wrote a very informative comment, but with the removal of
proc_cleanup_work it is no longer accurate.
Rewrite the comment so that it only talks about the details
that are still relevant, and hopefully is a little clearer.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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There remains no more code in the kernel using pids_ns->proc_mnt,
therefore remove it from the kernel.
The big benefit of this change is that one of the most error prone and
tricky parts of the pid namespace implementation, maintaining kernel
mounts of proc is removed.
In addition removing the unnecessary complexity of the kernel mount
fixes a regression that caused the proc mount options to be ignored.
Now that the initial mount of proc comes from userspace, those mount
options are again honored. This fixes Android's usage of the proc
hidepid option.
Reported-by: Alistair Strachan <astrachan@google.com>
Fixes: e94591d0d90c ("proc: Convert proc_mount to use mount_ns.")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Rework the flushing of proc to use a list of directory inodes that
need to be flushed.
The list is kept on struct pid not on struct task_struct, as there is
a fixed connection between proc inodes and pids but at least for the
case of de_thread the pid of a task_struct changes.
This removes the dependency on proc_mnt which allows for different
mounts of proc having different mount options even in the same pid
namespace and this allows for the removal of proc_mnt which will
trivially the first mount of proc to honor it's mount options.
This flushing remains an optimization. The functions
pid_delete_dentry and pid_revalidate ensure that ordinary dcache
management will not attempt to use dentries past the point their
respective task has died. When unused the shrinker will
eventually be able to remove these dentries.
There is a case in de_thread where proc_flush_pid can be
called early for a given pid. Which winds up being
safe (if suboptimal) as this is just an optiimization.
Only pid directories are put on the list as the other
per pid files are children of those directories and
d_invalidate on the directory will get them as well.
So that the pid can be used during flushing it's reference count is
taken in release_task and dropped in proc_flush_pid. Further the call
of proc_flush_pid is moved after the tasklist_lock is released in
release_task so that it is certain that the pid has already been
unhashed when flushing it taking place. This removes a small race
where a dentry could recreated.
As struct pid is supposed to be small and I need a per pid lock
I reuse the only lock that currently exists in struct pid the
the wait_pidfd.lock.
The net result is that this adds all of this functionality
with just a little extra list management overhead and
a single extra pointer in struct pid.
v2: Initialize pid->inodes. I somehow failed to get that
initialization into the initial version of the patch. A boot
failure was reported by "kernel test robot <lkp@intel.com>", and
failure to initialize that pid->inodes matches all of the reported
symptoms.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
"API:
- Fix out-of-sync IVs in self-test for IPsec AEAD algorithms
Algorithms:
- Use formally verified implementation of x86/curve25519
Drivers:
- Enhance hwrng support in caam
- Use crypto_engine for skcipher/aead/rsa/hash in caam
- Add Xilinx AES driver
- Add uacce driver
- Register zip engine to uacce in hisilicon
- Add support for OCTEON TX CPT engine in marvell"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits)
crypto: af_alg - bool type cosmetics
crypto: arm[64]/poly1305 - add artifact to .gitignore files
crypto: caam - limit single JD RNG output to maximum of 16 bytes
crypto: caam - enable prediction resistance in HRWNG
bus: fsl-mc: add api to retrieve mc version
crypto: caam - invalidate entropy register during RNG initialization
crypto: caam - check if RNG job failed
crypto: caam - simplify RNG implementation
crypto: caam - drop global context pointer and init_done
crypto: caam - use struct hwrng's .init for initialization
crypto: caam - allocate RNG instantiation descriptor with GFP_DMA
crypto: ccree - remove duplicated include from cc_aead.c
crypto: chelsio - remove set but not used variable 'adap'
crypto: marvell - enable OcteonTX cpt options for build
crypto: marvell - add the Virtual Function driver for CPT
crypto: marvell - add support for OCTEON TX CPT engine
crypto: marvell - create common Kconfig and Makefile for Marvell
crypto: arm/neon - memzero_explicit aes-cbc key
crypto: bcm - Use scnprintf() for avoiding potential buffer overflow
crypto: atmel-i2c - Fix wakeup fail
...
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Simplify the error handling in pcrypt_create_aead() by taking advantage
of crypto_grab_aead() now handling an ERR_PTR() name and by taking
advantage of crypto_drop_aead() now accepting (as a no-op) a spawn that
hasn't been grabbed yet.
This required also making padata_free_shell() accept a NULL argument.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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According to Geert's report[0],
kernel/padata.c: warning: 'err' may be used uninitialized in this
function [-Wuninitialized]: => 539:2
Warning is seen only with older compilers on certain archs. The
runtime effect is potentially returning garbage down the stack when
padata's cpumasks are modified before any pcrypt requests have run.
Simplest fix is to initialize err to the success value.
[0] http://lkml.kernel.org/r/20200210135506.11536-1-geert@linux-m68k.org
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: bbefa1dd6a6d ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues")
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>
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Pull networking updates from David Miller:
"Highlights:
1) Fix the iwlwifi regression, from Johannes Berg.
2) Support BSS coloring and 802.11 encapsulation offloading in
hardware, from John Crispin.
3) Fix some potential Spectre issues in qtnfmac, from Sergey
Matyukevich.
4) Add TTL decrement action to openvswitch, from Matteo Croce.
5) Allow paralleization through flow_action setup by not taking the
RTNL mutex, from Vlad Buslov.
6) A lot of zero-length array to flexible-array conversions, from
Gustavo A. R. Silva.
7) Align XDP statistics names across several drivers for consistency,
from Lorenzo Bianconi.
8) Add various pieces of infrastructure for offloading conntrack, and
make use of it in mlx5 driver, from Paul Blakey.
9) Allow using listening sockets in BPF sockmap, from Jakub Sitnicki.
10) Lots of parallelization improvements during configuration changes
in mlxsw driver, from Ido Schimmel.
11) Add support to devlink for generic packet traps, which report
packets dropped during ACL processing. And use them in mlxsw
driver. From Jiri Pirko.
12) Support bcmgenet on ACPI, from Jeremy Linton.
13) Make BPF compatible with RT, from Thomas Gleixnet, Alexei
Starovoitov, and your's truly.
14) Support XDP meta-data in virtio_net, from Yuya Kusakabe.
15) Fix sysfs permissions when network devices change namespaces, from
Christian Brauner.
16) Add a flags element to ethtool_ops so that drivers can more simply
indicate which coalescing parameters they actually support, and
therefore the generic layer can validate the user's ethtool
request. Use this in all drivers, from Jakub Kicinski.
17) Offload FIFO qdisc in mlxsw, from Petr Machata.
18) Support UDP sockets in sockmap, from Lorenz Bauer.
19) Fix stretch ACK bugs in several TCP congestion control modules,
from Pengcheng Yang.
20) Support virtual functiosn in octeontx2 driver, from Tomasz
Duszynski.
21) Add region operations for devlink and use it in ice driver to dump
NVM contents, from Jacob Keller.
22) Add support for hw offload of MACSEC, from Antoine Tenart.
23) Add support for BPF programs that can be attached to LSM hooks,
from KP Singh.
24) Support for multiple paths, path managers, and counters in MPTCP.
From Peter Krystad, Paolo Abeni, Florian Westphal, Davide Caratti,
and others.
25) More progress on adding the netlink interface to ethtool, from
Michal Kubecek"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2121 commits)
net: ipv6: rpl_iptunnel: Fix potential memory leak in rpl_do_srh_inline
cxgb4/chcr: nic-tls stats in ethtool
net: dsa: fix oops while probing Marvell DSA switches
net/bpfilter: remove superfluous testing message
net: macb: Fix handling of fixed-link node
net: dsa: ksz: Select KSZ protocol tag
netdevsim: dev: Fix memory leak in nsim_dev_take_snapshot_write
net: stmmac: add EHL 2.5Gbps PCI info and PCI ID
net: stmmac: add EHL PSE0 & PSE1 1Gbps PCI info and PCI ID
net: stmmac: create dwmac-intel.c to contain all Intel platform
net: dsa: bcm_sf2: Support specifying VLAN tag egress rule
net: dsa: bcm_sf2: Add support for matching VLAN TCI
net: dsa: bcm_sf2: Move writing of CFP_DATA(5) into slicing functions
net: dsa: bcm_sf2: Check earlier for FLOW_EXT and FLOW_MAC_EXT
net: dsa: bcm_sf2: Disable learning for ASP port
net: dsa: b53: Deny enslaving port 7 for 7278 into a bridge
net: dsa: b53: Prevent tagged VLAN on port 7 for 7278
net: dsa: b53: Restore VLAN entries upon (re)configuration
net: dsa: bcm_sf2: Fix overflow checks
hv_netvsc: Remove unnecessary round_up for recv_completion_cnt
...
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Signed-off-by: David S. Miller <davem@davemloft.net>
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Add new operation (LINK_UPDATE), which allows to replace active bpf_prog from
under given bpf_link. Currently this is only supported for bpf_cgroup_link,
but will be extended to other kinds of bpf_links in follow-up patches.
For bpf_cgroup_link, implemented functionality matches existing semantics for
direct bpf_prog attachment (including BPF_F_REPLACE flag). User can either
unconditionally set new bpf_prog regardless of which bpf_prog is currently
active under given bpf_link, or, optionally, can specify expected active
bpf_prog. If active bpf_prog doesn't match expected one, no changes are
performed, old bpf_link stays intact and attached, operation returns
a failure.
cgroup_bpf_replace() operation is resolving race between auto-detachment and
bpf_prog update in the same fashion as it's done for bpf_link detachment,
except in this case update has no way of succeeding because of target cgroup
marked as dying. So in this case error is returned.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200330030001.2312810-3-andriin@fb.com
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Implement new sub-command to attach cgroup BPF programs and return FD-based
bpf_link back on success. bpf_link, once attached to cgroup, cannot be
replaced, except by owner having its FD. Cgroup bpf_link supports only
BPF_F_ALLOW_MULTI semantics. Both link-based and prog-based BPF_F_ALLOW_MULTI
attachments can be freely intermixed.
To prevent bpf_cgroup_link from keeping cgroup alive past the point when no
BPF program can be executed, implement auto-detachment of link. When
cgroup_bpf_release() is called, all attached bpf_links are forced to release
cgroup refcounts, but they leave bpf_link otherwise active and allocated, as
well as still owning underlying bpf_prog. This is because user-space might
still have FDs open and active, so bpf_link as a user-referenced object can't
be freed yet. Once last active FD is closed, bpf_link will be freed and
underlying bpf_prog refcount will be dropped. But cgroup refcount won't be
touched, because cgroup is released already.
The inherent race between bpf_cgroup_link release (from closing last FD) and
cgroup_bpf_release() is resolved by both operations taking cgroup_mutex. So
the only additional check required is when bpf_cgroup_link attempts to detach
itself from cgroup. At that time we need to check whether there is still
cgroup associated with that link. And if not, exit with success, because
bpf_cgroup_link was already successfully detached.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/bpf/20200330030001.2312810-2-andriin@fb.com
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Further refine return values range in do_refine_retval_range by noting
these are int return types (We will assume here that int is a 32-bit type).
Two reasons to pull this out of original patch. First it makes the original
fix impossible to backport. And second I've not seen this as being problematic
in practice unlike the other case.
Fixes: 849fa50662fbc ("bpf/verifier: refine retval R0 state for bpf_get_stack helper")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158560421952.10843.12496354931526965046.stgit@john-Precision-5820-Tower
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It is not possible for the current verifier to track ALU32 and JMP ops
correctly. This can result in the verifier aborting with errors even though
the program should be verifiable. BPF codes that hit this can work around
it by changin int variables to 64-bit types, marking variables volatile,
etc. But this is all very ugly so it would be better to avoid these tricks.
But, the main reason to address this now is do_refine_retval_range() was
assuming return values could not be negative. Once we fixed this code that
was previously working will no longer work. See do_refine_retval_range()
patch for details. And we don't want to suddenly cause programs that used
to work to fail.
The simplest example code snippet that illustrates the problem is likely
this,
53: w8 = w0 // r8 <- [0, S32_MAX],
// w8 <- [-S32_MIN, X]
54: w8 <s 0 // r8 <- [0, U32_MAX]
// w8 <- [0, X]
The expected 64-bit and 32-bit bounds after each line are shown on the
right. The current issue is without the w* bounds we are forced to use
the worst case bound of [0, U32_MAX]. To resolve this type of case,
jmp32 creating divergent 32-bit bounds from 64-bit bounds, we add explicit
32-bit register bounds s32_{min|max}_value and u32_{min|max}_value. Then
from branch_taken logic creating new bounds we can track 32-bit bounds
explicitly.
The next case we observed is ALU ops after the jmp32,
53: w8 = w0 // r8 <- [0, S32_MAX],
// w8 <- [-S32_MIN, X]
54: w8 <s 0 // r8 <- [0, U32_MAX]
// w8 <- [0, X]
55: w8 += 1 // r8 <- [0, U32_MAX+1]
// w8 <- [0, X+1]
In order to keep the bounds accurate at this point we also need to track
ALU32 ops. To do this we add explicit ALU32 logic for each of the ALU
ops, mov, add, sub, etc.
Finally there is a question of how and when to merge bounds. The cases
enumerate here,
1. MOV ALU32 - zext 32-bit -> 64-bit
2. MOV ALU64 - copy 64-bit -> 32-bit
3. op ALU32 - zext 32-bit -> 64-bit
4. op ALU64 - n/a
5. jmp ALU32 - 64-bit: var32_off | upper_32_bits(var64_off)
6. jmp ALU64 - 32-bit: (>> (<< var64_off))
Details for each case,
For "MOV ALU32" BPF arch zero extends so we simply copy the bounds
from 32-bit into 64-bit ensuring we truncate var_off and 64-bit
bounds correctly. See zext_32_to_64.
For "MOV ALU64" copy all bounds including 32-bit into new register. If
the src register had 32-bit bounds the dst register will as well.
For "op ALU32" zero extend 32-bit into 64-bit the same as move,
see zext_32_to_64.
For "op ALU64" calculate both 32-bit and 64-bit bounds no merging
is done here. Except we have a special case. When RSH or ARSH is
done we can't simply ignore shifting bits from 64-bit reg into the
32-bit subreg. So currently just push bounds from 64-bit into 32-bit.
This will be correct in the sense that they will represent a valid
state of the register. However we could lose some accuracy if an
ARSH is following a jmp32 operation. We can handle this special
case in a follow up series.
For "jmp ALU32" mark 64-bit reg unknown and recalculate 64-bit bounds
from tnum by setting var_off to ((<<(>>var_off)) | var32_off). We
special case if 64-bit bounds has zero'd upper 32bits at which point
we can simply copy 32-bit bounds into 64-bit register. This catches
a common compiler trick where upper 32-bits are zeroed and then
32-bit ops are used followed by a 64-bit compare or 64-bit op on
a pointer. See __reg_combine_64_into_32().
For "jmp ALU64" cast the bounds of the 64bit to their 32-bit
counterpart. For example s32_min_value = (s32)reg->smin_value. For
tnum use only the lower 32bits via, (>>(<<var_off)). See
__reg_combine_64_into_32().
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158560419880.10843.11448220440809118343.stgit@john-Precision-5820-Tower
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do_refine_retval_range() is called to refine return values from specified
helpers, probe_read_str and get_stack at the moment, the reasoning is
because both have a max value as part of their input arguments and
because the helper ensure the return value will not be larger than this
we can set smax values of the return register, r0.
However, the return value is a signed integer so setting umax is incorrect
It leads to further confusion when the do_refine_retval_range() then calls,
__reg_deduce_bounds() which will see a umax value as meaning the value is
unsigned and then assuming it is unsigned set the smin = umin which in this
case results in 'smin = 0' and an 'smax = X' where X is the input argument
from the helper call.
Here are the comments from _reg_deduce_bounds() on why this would be safe
to do.
/* Learn sign from unsigned bounds. Signed bounds cross the sign
* boundary, so we must be careful.
*/
if ((s64)reg->umax_value >= 0) {
/* Positive. We can't learn anything from the smin, but smax
* is positive, hence safe.
*/
reg->smin_value = reg->umin_value;
reg->smax_value = reg->umax_value = min_t(u64, reg->smax_value,
reg->umax_value);
But now we incorrectly have a return value with type int with the
signed bounds (0,X). Suppose the return value is negative, which is
possible the we have the verifier and reality out of sync. Among other
things this may result in any error handling code being falsely detected
as dead-code and removed. For instance the example below shows using
bpf_probe_read_str() causes the error path to be identified as dead
code and removed.
>From the 'llvm-object -S' dump,
r2 = 100
call 45
if r0 s< 0 goto +4
r4 = *(u32 *)(r7 + 0)
But from dump xlate
(b7) r2 = 100
(85) call bpf_probe_read_compat_str#-96768
(61) r4 = *(u32 *)(r7 +0) <-- dropped if goto
Due to verifier state after call being
R0=inv(id=0,umax_value=100,var_off=(0x0; 0x7f))
To fix omit setting the umax value because its not safe. The only
actual bounds we know is the smax. This results in the correct bounds
(SMIN, X) where X is the max length from the helper. After this the
new verifier state looks like the following after call 45.
R0=inv(id=0,smax_value=100)
Then xlated version no longer removed dead code giving the expected
result,
(b7) r2 = 100
(85) call bpf_probe_read_compat_str#-96768
(c5) if r0 s< 0x0 goto pc+4
(61) r4 = *(u32 *)(r7 +0)
Note, bpf_probe_read_* calls are root only so we wont hit this case
with non-root bpf users.
v3: comment had some documentation about meta set to null case which
is not relevant here and confusing to include in the comment.
v2 note: In original version we set msize_smax_value from check_func_arg()
and propagated this into smax of retval. The logic was smax is the bound
on the retval we set and because the type in the helper is ARG_CONST_SIZE
we know that the reg is a positive tnum_const() so umax=smax. Alexei
pointed out though this is a bit odd to read because the register in
check_func_arg() has a C type of u32 and the umax bound would be the
normally relavent bound here. Pulling in extra knowledge about future
checks makes reading the code a bit tricky. Further having a signed
meta data that can only ever be positive is also a bit odd. So dropped
the msize_smax_value metadata and made it a u64 msize_max_value to
indicate its unsigned. And additionally save bound from umax value in
check_arg_funcs which is the same as smax due to as noted above tnumx_cont
and negative check but reads better. By my analysis nothing functionally
changes in v2 but it does get easier to read so that is win.
Fixes: 849fa50662fbc ("bpf/verifier: refine retval R0 state for bpf_get_stack helper")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158560417900.10843.14351995140624628941.stgit@john-Precision-5820-Tower
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The bounds checking for the arguments accessed in the BPF program breaks
when the expected_attach_type is not BPF_TRACE_FEXIT, BPF_LSM_MAC or
BPF_MODIFY_RETURN resulting in no check being done for the default case
(the programs which do not receive the return value of the attached
function in its arguments) when the index of the argument being accessed
is equal to the number of arguments (nr_args).
This was a result of a misplaced "else if" block introduced by the
Commit 6ba43b761c41 ("bpf: Attachment verification for
BPF_MODIFY_RETURN")
Fixes: 6ba43b761c41 ("bpf: Attachment verification for BPF_MODIFY_RETURN")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200330144246.338-1-kpsingh@chromium.org
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reg_set_min_max_inv() contains exactly the same logic as reg_set_min_max(),
just flipped around. While this makes sense in a cBPF verifier (where ALU
operations are not symmetric), it does not make sense for eBPF.
Replace reg_set_min_max_inv() with a helper that flips the opcode around,
then lets reg_set_min_max() do the complicated work.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200330160324.15259-4-daniel@iogearbox.net
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The BPF verifier tried to track values based on 32-bit comparisons by
(ab)using the tnum state via 581738a681b6 ("bpf: Provide better register
bounds after jmp32 instructions"). The idea is that after a check like
this:
if ((u32)r0 > 3)
exit
We can't meaningfully constrain the arithmetic-range-based tracking, but
we can update the tnum state to (value=0,mask=0xffff'ffff'0000'0003).
However, the implementation from 581738a681b6 didn't compute the tnum
constraint based on the fixed operand, but instead derives it from the
arithmetic-range-based tracking. This means that after the following
sequence of operations:
if (r0 >= 0x1'0000'0001)
exit
if ((u32)r0 > 7)
exit
The verifier assumed that the lower half of r0 is in the range (0, 0)
and apply the tnum constraint (value=0,mask=0xffff'ffff'0000'0000) thus
causing the overall tnum to be (value=0,mask=0x1'0000'0000), which was
incorrect. Provide a fixed implementation.
Fixes: 581738a681b6 ("bpf: Provide better register bounds after jmp32 instructions")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200330160324.15259-3-daniel@iogearbox.net
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Anatoly has been fuzzing with kBdysch harness and reported a hang in
one of the outcomes:
0: (b7) r0 = 808464432
1: (7f) r0 >>= r0
2: (14) w0 -= 808464432
3: (07) r0 += 808464432
4: (b7) r1 = 808464432
5: (de) if w1 s<= w0 goto pc+0
R0_w=invP(id=0,umin_value=808464432,umax_value=5103431727,var_off=(0x30303020;0x10000001f)) R1_w=invP808464432 R10=fp0
6: (07) r0 += -2144337872
7: (14) w0 -= -1607454672
8: (25) if r0 > 0x30303030 goto pc+0
R0_w=invP(id=0,umin_value=271581184,umax_value=271581311,var_off=(0x10300000;0x7f)) R1_w=invP808464432 R10=fp0
9: (76) if w0 s>= 0x303030 goto pc+2
12: (95) exit
from 8 to 9: safe
from 5 to 6: R0_w=invP(id=0,umin_value=808464432,umax_value=5103431727,var_off=(0x30303020;0x10000001f)) R1_w=invP808464432 R10=fp0
6: (07) r0 += -2144337872
7: (14) w0 -= -1607454672
8: (25) if r0 > 0x30303030 goto pc+0
R0_w=invP(id=0,umin_value=271581184,umax_value=271581311,var_off=(0x10300000;0x7f)) R1_w=invP808464432 R10=fp0
9: safe
from 8 to 9: safe
verification time 589 usec
stack depth 0
processed 17 insns (limit 1000000) [...]
The underlying program was xlated as follows:
# bpftool p d x i 9
0: (b7) r0 = 808464432
1: (7f) r0 >>= r0
2: (14) w0 -= 808464432
3: (07) r0 += 808464432
4: (b7) r1 = 808464432
5: (de) if w1 s<= w0 goto pc+0
6: (07) r0 += -2144337872
7: (14) w0 -= -1607454672
8: (25) if r0 > 0x30303030 goto pc+0
9: (76) if w0 s>= 0x303030 goto pc+2
10: (05) goto pc-1
11: (05) goto pc-1
12: (95) exit
The verifier rewrote original instructions it recognized as dead code with
'goto pc-1', but reality differs from verifier simulation in that we're
actually able to trigger a hang due to hitting the 'goto pc-1' instructions.
Taking different examples to make the issue more obvious: in this example
we're probing bounds on a completely unknown scalar variable in r1:
[...]
5: R0_w=inv1 R1_w=inv(id=0) R10=fp0
5: (18) r2 = 0x4000000000
7: R0_w=inv1 R1_w=inv(id=0) R2_w=inv274877906944 R10=fp0
7: (18) r3 = 0x2000000000
9: R0_w=inv1 R1_w=inv(id=0) R2_w=inv274877906944 R3_w=inv137438953472 R10=fp0
9: (18) r4 = 0x400
11: R0_w=inv1 R1_w=inv(id=0) R2_w=inv274877906944 R3_w=inv137438953472 R4_w=inv1024 R10=fp0
11: (18) r5 = 0x200
13: R0_w=inv1 R1_w=inv(id=0) R2_w=inv274877906944 R3_w=inv137438953472 R4_w=inv1024 R5_w=inv512 R10=fp0
13: (2d) if r1 > r2 goto pc+4
R0_w=inv1 R1_w=inv(id=0,umax_value=274877906944,var_off=(0x0; 0x7fffffffff)) R2_w=inv274877906944 R3_w=inv137438953472 R4_w=inv1024 R5_w=inv512 R10=fp0
14: R0_w=inv1 R1_w=inv(id=0,umax_value=274877906944,var_off=(0x0; 0x7fffffffff)) R2_w=inv274877906944 R3_w=inv137438953472 R4_w=inv1024 R5_w=inv512 R10=fp0
14: (ad) if r1 < r3 goto pc+3
R0_w=inv1 R1_w=inv(id=0,umin_value=137438953472,umax_value=274877906944,var_off=(0x0; 0x7fffffffff)) R2_w=inv274877906944 R3_w=inv137438953472 R4_w=inv1024 R5_w=inv512 R10=fp0
15: R0=inv1 R1=inv(id=0,umin_value=137438953472,umax_value=274877906944,var_off=(0x0; 0x7fffffffff)) R2=inv274877906944 R3=inv137438953472 R4=inv1024 R5=inv512 R10=fp0
15: (2e) if w1 > w4 goto pc+2
R0=inv1 R1=inv(id=0,umin_value=137438953472,umax_value=274877906944,var_off=(0x0; 0x7f00000000)) R2=inv274877906944 R3=inv137438953472 R4=inv1024 R5=inv512 R10=fp0
16: R0=inv1 R1=inv(id=0,umin_value=137438953472,umax_value=274877906944,var_off=(0x0; 0x7f00000000)) R2=inv274877906944 R3=inv137438953472 R4=inv1024 R5=inv512 R10=fp0
16: (ae) if w1 < w5 goto pc+1
R0=inv1 R1=inv(id=0,umin_value=137438953472,umax_value=274877906944,var_off=(0x0; 0x7f00000000)) R2=inv274877906944 R3=inv137438953472 R4=inv1024 R5=inv512 R10=fp0
[...]
We're first probing lower/upper bounds via jmp64, later we do a similar
check via jmp32 and examine the resulting var_off there. After fall-through
in insn 14, we get the following bounded r1 with 0x7fffffffff unknown marked
bits in the variable section.
Thus, after knowing r1 <= 0x4000000000 and r1 >= 0x2000000000:
max: 0b100000000000000000000000000000000000000 / 0x4000000000
var: 0b111111111111111111111111111111111111111 / 0x7fffffffff
min: 0b010000000000000000000000000000000000000 / 0x2000000000
Now, in insn 15 and 16, we perform a similar probe with lower/upper bounds
in jmp32.
Thus, after knowing r1 <= 0x4000000000 and r1 >= 0x2000000000 and
w1 <= 0x400 and w1 >= 0x200:
max: 0b100000000000000000000000000000000000000 / 0x4000000000
var: 0b111111100000000000000000000000000000000 / 0x7f00000000
min: 0b010000000000000000000000000000000000000 / 0x2000000000
The lower/upper bounds haven't changed since they have high bits set in
u64 space and the jmp32 tests can only refine bounds in the low bits.
However, for the var part the expectation would have been 0x7f000007ff
or something less precise up to 0x7fffffffff. A outcome of 0x7f00000000
is not correct since it would contradict the earlier probed bounds
where we know that the result should have been in [0x200,0x400] in u32
space. Therefore, tests with such info will lead to wrong verifier
assumptions later on like falsely predicting conditional jumps to be
always taken, etc.
The issue here is that __reg_bound_offset32()'s implementation from
commit 581738a681b6 ("bpf: Provide better register bounds after jmp32
instructions") makes an incorrect range assumption:
static void __reg_bound_offset32(struct bpf_reg_state *reg)
{
u64 mask = 0xffffFFFF;
struct tnum range = tnum_range(reg->umin_value & mask,
reg->umax_value & mask);
struct tnum lo32 = tnum_cast(reg->var_off, 4);
struct tnum hi32 = tnum_lshift(tnum_rshift(reg->var_off, 32), 32);
reg->var_off = tnum_or(hi32, tnum_intersect(lo32, range));
}
In the above walk-through example, __reg_bound_offset32() as-is chose
a range after masking with 0xffffffff of [0x0,0x0] since umin:0x2000000000
and umax:0x4000000000 and therefore the lo32 part was clamped to 0x0 as
well. However, in the umin:0x2000000000 and umax:0x4000000000 range above
we'd end up with an actual possible interval of [0x0,0xffffffff] for u32
space instead.
In case of the original reproducer, the situation looked as follows at
insn 5 for r0:
[...]
5: R0_w=invP(id=0,umin_value=808464432,umax_value=5103431727,var_off=(0x0; 0x1ffffffff)) R1_w=invP808464432 R10=fp0
0x30303030 0x13030302f
5: (de) if w1 s<= w0 goto pc+0
R0_w=invP(id=0,umin_value=808464432,umax_value=5103431727,var_off=(0x30303020; 0x10000001f)) R1_w=invP808464432 R10=fp0
0x30303030 0x13030302f
[...]
After the fall-through, we similarly forced the var_off result into
the wrong range [0x30303030,0x3030302f] suggesting later on that fixed
bits must only be of 0x30303020 with 0x10000001f unknowns whereas such
assumption can only be made when both bounds in hi32 range match.
Originally, I was thinking to fix this by moving reg into a temp reg and
use proper coerce_reg_to_size() helper on the temp reg where we can then
based on that define the range tnum for later intersection:
static void __reg_bound_offset32(struct bpf_reg_state *reg)
{
struct bpf_reg_state tmp = *reg;
struct tnum lo32, hi32, range;
coerce_reg_to_size(&tmp, 4);
range = tnum_range(tmp.umin_value, tmp.umax_value);
lo32 = tnum_cast(reg->var_off, 4);
hi32 = tnum_lshift(tnum_rshift(reg->var_off, 32), 32);
reg->var_off = tnum_or(hi32, tnum_intersect(lo32, range));
}
In the case of the concrete example, this gives us a more conservative unknown
section. Thus, after knowing r1 <= 0x4000000000 and r1 >= 0x2000000000 and
w1 <= 0x400 and w1 >= 0x200:
max: 0b100000000000000000000000000000000000000 / 0x4000000000
var: 0b111111111111111111111111111111111111111 / 0x7fffffffff
min: 0b010000000000000000000000000000000000000 / 0x2000000000
However, above new __reg_bound_offset32() has no effect on refining the
knowledge of the register contents. Meaning, if the bounds in hi32 range
mismatch we'll get the identity function given the range reg spans
[0x0,0xffffffff] and we cast var_off into lo32 only to later on binary
or it again with the hi32.
Likewise, if the bounds in hi32 range match, then we mask both bounds
with 0xffffffff, use the resulting umin/umax for the range to later
intersect the lo32 with it. However, _prior_ called __reg_bound_offset()
did already such intersection on the full reg and we therefore would only
repeat the same operation on the lo32 part twice.
Given this has no effect and the original commit had false assumptions,
this patch reverts the code entirely which is also more straight forward
for stable trees: apparently 581738a681b6 got auto-selected by Sasha's
ML system and misclassified as a fix, so it got sucked into v5.4 where
it should never have landed. A revert is low-risk also from a user PoV
since it requires a recent kernel and llc to opt-into -mcpu=v3 BPF CPU
to generate jmp32 instructions. A proper bounds refinement would need a
significantly more complex approach which is currently being worked, but
no stable material [0]. Hence revert is best option for stable. After the
revert, the original reported program gets rejected as follows:
1: (7f) r0 >>= r0
2: (14) w0 -= 808464432
3: (07) r0 += 808464432
4: (b7) r1 = 808464432
5: (de) if w1 s<= w0 goto pc+0
R0_w=invP(id=0,umin_value=808464432,umax_value=5103431727,var_off=(0x0; 0x1ffffffff)) R1_w=invP808464432 R10=fp0
6: (07) r0 += -2144337872
7: (14) w0 -= -1607454672
8: (25) if r0 > 0x30303030 goto pc+0
R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x3fffffff)) R1_w=invP808464432 R10=fp0
9: (76) if w0 s>= 0x303030 goto pc+2
R0=invP(id=0,umax_value=3158063,var_off=(0x0; 0x3fffff)) R1=invP808464432 R10=fp0
10: (30) r0 = *(u8 *)skb[808464432]
BPF_LD_[ABS|IND] uses reserved fields
processed 11 insns (limit 1000000) [...]
[0] https://lore.kernel.org/bpf/158507130343.15666.8018068546764556975.stgit@john-Precision-5820-Tower/T/
Fixes: 581738a681b6 ("bpf: Provide better register bounds after jmp32 instructions")
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200330160324.15259-2-daniel@iogearbox.net
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JITed BPF programs are dynamically attached to the LSM hooks
using BPF trampolines. The trampoline prologue generates code to handle
conversion of the signature of the hook to the appropriate BPF context.
The allocated trampoline programs are attached to the nop functions
initialized as LSM hooks.
BPF_PROG_TYPE_LSM programs must have a GPL compatible license and
and need CAP_SYS_ADMIN (required for loading eBPF programs).
Upon attachment:
* A BPF fexit trampoline is used for LSM hooks with a void return type.
* A BPF fmod_ret trampoline is used for LSM hooks which return an
int. The attached programs can override the return value of the
bpf LSM hook to indicate a MAC Policy decision.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Florent Revest <revest@google.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/bpf/20200329004356.27286-5-kpsingh@chromium.org
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When CONFIG_BPF_LSM is enabled, nop functions, bpf_lsm_<hook_name>, are
generated for each LSM hook. These functions are initialized as LSM
hooks in a subsequent patch.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Florent Revest <revest@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/bpf/20200329004356.27286-4-kpsingh@chromium.org
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Introduce types and configs for bpf programs that can be attached to
LSM hooks. The programs can be enabled by the config option
CONFIG_BPF_LSM.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Florent Revest <revest@google.com>
Reviewed-by: Thomas Garnier <thgarnie@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/bpf/20200329004356.27286-2-kpsingh@chromium.org
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Enable the bpf_get_current_cgroup_id() helper for connect(), sendmsg(),
recvmsg() and bind-related hooks in order to retrieve the cgroup v2
context which can then be used as part of the key for BPF map lookups,
for example. Given these hooks operate in process context 'current' is
always valid and pointing to the app that is performing mentioned
syscalls if it's subject to a v2 cgroup. Also with same motivation of
commit 7723628101aa ("bpf: Introduce bpf_skb_ancestor_cgroup_id helper")
enable retrieval of ancestor from current so the cgroup id can be used
for policy lookups which can then forbid connect() / bind(), for example.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/d2a7ef42530ad299e3cbb245e6c12374b72145ef.1585323121.git.daniel@iogearbox.net
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In Cilium we're mainly using BPF cgroup hooks today in order to implement
kube-proxy free Kubernetes service translation for ClusterIP, NodePort (*),
ExternalIP, and LoadBalancer as well as HostPort mapping [0] for all traffic
between Cilium managed nodes. While this works in its current shape and avoids
packet-level NAT for inter Cilium managed node traffic, there is one major
limitation we're facing today, that is, lack of netns awareness.
In Kubernetes, the concept of Pods (which hold one or multiple containers)
has been built around network namespaces, so while we can use the global scope
of attaching to root BPF cgroup hooks also to our advantage (e.g. for exposing
NodePort ports on loopback addresses), we also have the need to differentiate
between initial network namespaces and non-initial one. For example, ExternalIP
services mandate that non-local service IPs are not to be translated from the
host (initial) network namespace as one example. Right now, we have an ugly
work-around in place where non-local service IPs for ExternalIP services are
not xlated from connect() and friends BPF hooks but instead via less efficient
packet-level NAT on the veth tc ingress hook for Pod traffic.
On top of determining whether we're in initial or non-initial network namespace
we also have a need for a socket-cookie like mechanism for network namespaces
scope. Socket cookies have the nice property that they can be combined as part
of the key structure e.g. for BPF LRU maps without having to worry that the
cookie could be recycled. We are planning to use this for our sessionAffinity
implementation for services. Therefore, add a new bpf_get_netns_cookie() helper
which would resolve both use cases at once: bpf_get_netns_cookie(NULL) would
provide the cookie for the initial network namespace while passing the context
instead of NULL would provide the cookie from the application's network namespace.
We're using a hole, so no size increase; the assignment happens only once.
Therefore this allows for a comparison on initial namespace as well as regular
cookie usage as we have today with socket cookies. We could later on enable
this helper for other program types as well as we would see need.
(*) Both externalTrafficPolicy={Local|Cluster} types
[0] https://github.com/cilium/cilium/blob/master/bpf/bpf_sock.c
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/c47d2346982693a9cf9da0e12690453aded4c788.1585323121.git.daniel@iogearbox.net
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kernel/bpf/syscall.c:2263:34: warning: 'bpf_xdp_link_lops' defined but not used [-Wunused-const-variable=]
static const struct bpf_link_ops bpf_xdp_link_lops;
^~~~~~~~~~~~~~~~~
commit 70ed506c3bbc ("bpf: Introduce pinnable bpf_link abstraction")
involded this unused variable, remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200326031613.19372-1-yuehaibing@huawei.com
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Factor out logic mapping expected program attach type to program type and
subsequent handling of program attach/detach. Also list out all supported
cgroup BPF program types explicitly to prevent accidental bugs once more
program types are added to a mapping. Do the same for prog_query API.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200325065746.640559-3-andriin@fb.com
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Refactor cgroup attach/detach code to abstract away common operations
performed on all types of cgroup storages. This makes high-level logic more
apparent, plus allows to reuse more code across multiple functions.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200325065746.640559-2-andriin@fb.com
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Currently, for all op verification we call __red_deduce_bounds() and
__red_bound_offset() but we only call __update_reg_bounds() in bitwise
ops. However, we could benefit from calling __update_reg_bounds() in
BPF_ADD, BPF_SUB, and BPF_MUL cases as well.
For example, a register with state 'R1_w=invP0' when we subtract from
it,
w1 -= 2
Before coerce we will now have an smin_value=S64_MIN, smax_value=U64_MAX
and unsigned bounds umin_value=0, umax_value=U64_MAX. These will then
be clamped to S32_MIN, U32_MAX values by coerce in the case of alu32 op
as done in above example. However tnum will be a constant because the
ALU op is done on a constant.
Without update_reg_bounds() we have a scenario where tnum is a const
but our unsigned bounds do not reflect this. By calling update_reg_bounds
after coerce to 32bit we further refine the umin_value to U64_MAX in the
alu64 case or U32_MAX in the alu32 case above.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158507151689.15666.566796274289413203.stgit@john-Precision-5820-Tower
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Pull per op ALU logic into individual functions. We are about to add
u32 versions of each of these by pull them out the code gets a bit
more readable here and nicer in the next patch.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158507149518.15666.15672349629329072411.stgit@john-Precision-5820-Tower
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Simplify gen_btf logic to make it work with llvm-objcopy. The existing
'file format' and 'architecture' parsing logic is brittle and does not
work with llvm-objcopy/llvm-objdump.
'file format' output of llvm-objdump>=11 will match GNU objdump, but
'architecture' (bfdarch) may not.
.BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag
because it is part of vmlinux image used for introspection. C code
can reference the section via linker script defined __start_BTF and
__stop_BTF. This fixes a small problem that previous .BTF had the
SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data).
Additionally, `objcopy -I binary` synthesized symbols
_binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not
used elsewhere) are replaced with more commonplace __start_BTF and
__stop_BTF.
Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns
"empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?"
We use a dd command to change the e_type field in the ELF header from
ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting
ET_EXEC as an input file is an extremely rare GNU ld feature that lld
does not intend to support, because this is error-prone.
The output section description .BTF in include/asm-generic/vmlinux.lds.h
avoids potential subtle orphan section placement issues and suppresses
--orphan-handling=warn warnings.
Fixes: df786c9b9476 ("bpf: Force .BTF section start to zero when dumping from vmlinux")
Fixes: cb0cc635c7a9 ("powerpc: Include .BTF section")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://github.com/ClangBuiltLinux/linux/issues/871
Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com
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Minor comment conflict in mac80211.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Overlapping header include additions in macsec.c
A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c
Overlapping test additions in selftests Makefile
Overlapping PCI ID table adjustments in iwlwifi driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Daniel Borkmann says:
====================
pull-request: bpf-next 2020-03-13
The following pull-request contains BPF updates for your *net-next* tree.
We've added 86 non-merge commits during the last 12 day(s) which contain
a total of 107 files changed, 5771 insertions(+), 1700 deletions(-).
The main changes are:
1) Add modify_return attach type which allows to attach to a function via
BPF trampoline and is run after the fentry and before the fexit programs
and can pass a return code to the original caller, from KP Singh.
2) Generalize BPF's kallsyms handling and add BPF trampoline and dispatcher
objects to be visible in /proc/kallsyms so they can be annotated in
stack traces, from Jiri Olsa.
3) Extend BPF sockmap to allow for UDP next to existing TCP support in order
in order to enable this for BPF based socket dispatch, from Lorenz Bauer.
4) Introduce a new bpftool 'prog profile' command which attaches to existing
BPF programs via fentry and fexit hooks and reads out hardware counters
during that period, from Song Liu. Example usage:
bpftool prog profile id 337 duration 3 cycles instructions llc_misses
4228 run_cnt
3403698 cycles (84.08%)
3525294 instructions # 1.04 insn per cycle (84.05%)
13 llc_misses # 3.69 LLC misses per million isns (83.50%)
5) Batch of improvements to libbpf, bpftool and BPF selftests. Also addition
of a new bpf_link abstraction to keep in particular BPF tracing programs
attached even when the applicaion owning them exits, from Andrii Nakryiko.
6) New bpf_get_current_pid_tgid() helper for tracing to perform PID filtering
and which returns the PID as seen by the init namespace, from Carlos Neira.
7) Refactor of RISC-V JIT code to move out common pieces and addition of a
new RV32G BPF JIT compiler, from Luke Nelson.
8) Add gso_size context member to __sk_buff in order to be able to know whether
a given skb is GSO or not, from Willem de Bruijn.
9) Add a new bpf_xdp_output() helper which reuses XDP's existing perf RB output
implementation but can be called from tracepoint programs, from Eelco Chaudron.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Sparse reports a warning at __bpf_prog_enter() and __bpf_prog_exit()
warning: context imbalance in __bpf_prog_enter() - wrong count at exit
warning: context imbalance in __bpf_prog_exit() - unexpected unlock
The root cause is the missing annotation at __bpf_prog_enter()
and __bpf_prog_exit()
Add the missing __acquires(RCU) annotation
Add the missing __releases(RCU) annotation
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200311010908.42366-2-jbi.octave@gmail.com
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Now that we have all the objects (bpf_prog, bpf_trampoline,
bpf_dispatcher) linked in bpf_tree, there's no need to have
separate bpf_image tree for images.
Reverting the bpf_image tree together with struct bpf_image,
because it's no longer needed.
Also removing bpf_image_alloc function and adding the original
bpf_jit_alloc_exec_page interface instead.
The kernel_text_address function can now rely only on is_bpf_text_address,
because it checks the bpf_tree that contains all the objects.
Keeping bpf_image_ksym_add and bpf_image_ksym_del because they are
useful wrappers with perf's ksymbol interface calls.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-13-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Adding dispatchers to kallsyms. It's displayed as
bpf_dispatcher_<NAME>
where NAME is the name of dispatcher.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-12-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Adding trampolines to kallsyms. It's displayed as
bpf_trampoline_<ID> [bpf]
where ID is the BTF id of the trampoline function.
Adding bpf_image_ksym_add/del functions that setup
the start/end values and call KSYMBOL perf events
handlers.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Separating /proc/kallsyms add/del code and adding bpf_ksym_add/del
functions for that.
Moving bpf_prog_ksym_node_add/del functions to __bpf_ksym_add/del
and changing their argument to 'struct bpf_ksym' object. This way
we can call them for other bpf objects types like trampoline and
dispatcher.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Adding 'prog' bool flag to 'struct bpf_ksym' to mark that
this object belongs to bpf_prog object.
This change allows having bpf_prog objects together with
other types (trampolines and dispatchers) in the single
bpf_tree. It's used when searching for bpf_prog exception
tables by the bpf_prog_ksym_find function, where we need
to get the bpf_prog pointer.
>From now we can safely add bpf_ksym support for trampoline
or dispatcher objects, because we can differentiate them
from bpf_prog objects.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-9-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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