Pull live patching infrastructure from Jiri Kosina:
"Let me provide a bit of history first, before describing what is in
this pile.
Originally, there was kSplice as a standalone project that implemented
stop_machine()-based patching for the linux kernel. This project got
later acquired, and the current owner is providing live patching as a
proprietary service, without any intentions to have their
implementation merged.
Then, due to rising user/customer demand, both Red Hat and SUSE
started working on their own implementation (not knowing about each
other), and announced first versions roughly at the same time [1] [2].
The principle difference between the two solutions is how they are
making sure that the patching is performed in a consistent way when it
comes to different execution threads with respect to the semantic
nature of the change that is being introduced.
In a nutshell, kPatch is issuing stop_machine(), then looking at
stacks of all existing processess, and if it decides that the system
is in a state that can be patched safely, it proceeds insterting code
redirection machinery to the patched functions.
On the other hand, kGraft provides a per-thread consistency during one
single pass of a process through the kernel and performs a lazy
contignuous migration of threads from "unpatched" universe to the
"patched" one at safe checkpoints.
If interested in a more detailed discussion about the consistency
models and its possible combinations, please see the thread that
evolved around [3].
It pretty quickly became obvious to the interested parties that it's
absolutely impractical in this case to have several isolated solutions
for one task to co-exist in the kernel. During a dedicated Live
Kernel Patching track at LPC in Dusseldorf, all the interested parties
sat together and came up with a joint aproach that would work for both
distro vendors. Steven Rostedt took notes [4] from this meeting.
And the foundation for that aproach is what's present in this pull
request.
It provides a basic infrastructure for function "live patching" (i.e.
code redirection), including API for kernel modules containing the
actual patches, and API/ABI for userspace to be able to operate on the
patches (look up what patches are applied, enable/disable them, etc).
It's relatively simple and minimalistic, as it's making use of
existing kernel infrastructure (namely ftrace) as much as possible.
It's also self-contained, in a sense that it doesn't hook itself in
any other kernel subsystem (it doesn't even touch any other code).
It's now implemented for x86 only as a reference architecture, but
support for powerpc, s390 and arm is already in the works (adding
arch-specific support basically boils down to teaching ftrace about
regs-saving).
Once this common infrastructure gets merged, both Red Hat and SUSE
have agreed to immediately start porting their current solutions on
top of this, abandoning their out-of-tree code. The plan basically is
that each patch will be marked by flag(s) that would indicate which
consistency model it is willing to use (again, the details have been
sketched out already in the thread at [3]).
Before this happens, the current codebase can be used to patch a large
group of secruity/stability problems the patches for which are not too
complex (in a sense that they don't introduce non-trivial change of
function's return value semantics, they don't change layout of data
structures, etc) -- this corresponds to LEAVE_FUNCTION &&
SWITCH_FUNCTION semantics described at [3].
This tree has been in linux-next since December.
[1] https://lkml.org/lkml/2014/4/30/477
[2] https://lkml.org/lkml/2014/7/14/857
[3] https://lkml.org/lkml/2014/11/7/354
[4] http://linuxplumbersconf.org/2014/wp-content/uploads/2014/10/LPC2014_LivePatching.txt
[ The core code is introduced by the three commits authored by Seth
Jennings, which got a lot of changes incorporated during numerous
respins and reviews of the initial implementation. All the followup
commits have materialized only after public tree has been created,
so they were not folded into initial three commits so that the
public tree doesn't get rebased ]"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: add missing newline to error message
livepatch: rename config to CONFIG_LIVEPATCH
livepatch: fix uninitialized return value
livepatch: support for repatching a function
livepatch: enforce patch stacking semantics
livepatch: change ARCH_HAVE_LIVE_PATCHING to HAVE_LIVE_PATCHING
livepatch: fix deferred module patching order
livepatch: handle ancient compilers with more grace
livepatch: kconfig: use bool instead of boolean
livepatch: samples: fix usage example comments
livepatch: MAINTAINERS: add git tree location
livepatch: use FTRACE_OPS_FL_IPMODIFY
livepatch: move x86 specific ftrace handler code to arch/x86
livepatch: samples: add sample live patching module
livepatch: kernel: add support for live patching
livepatch: kernel: add TAINT_LIVEPATCH
Rename CONFIG_LIVE_PATCHING to CONFIG_LIVEPATCH to make the naming of
the config and the code more consistent.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
hash map is unordered, so get_next_key() iterator shouldn't
rely on particular order of elements. So relax this test.
Fixes: ffb65f27a1 ("bpf: add a testsuite for eBPF maps")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix a few typos in the livepatch-sample.c usage example comments and add
some whitespace to make the comments a little more legible.
Reported-by: Udo Seidel <udoseidel@gmx.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
sockex2_kern.c is purposefully large eBPF program in C.
llvm compiles ~200 lines of C code into ~300 eBPF instructions.
It's similar to __skb_flow_dissect() to demonstrate that complex packet parsing
can be done by eBPF.
Then it uses (struct flow_keys)->dst IP address (or hash of ipv6 dst) to keep
stats of number of packets per IP.
User space loads eBPF program, attaches it to loopback interface and prints
dest_ip->#packets stats every second.
Usage:
$sudo samples/bpf/sockex2
ip 127.0.0.1 count 19
ip 127.0.0.1 count 178115
ip 127.0.0.1 count 369437
ip 127.0.0.1 count 559841
ip 127.0.0.1 count 750539
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
this example does the same task as previous socket example
in assembler, but this one does it in C.
eBPF program in kernel does:
/* assume that packet is IPv4, load one byte of IP->proto */
int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
long *value;
value = bpf_map_lookup_elem(&my_map, &index);
if (value)
__sync_fetch_and_add(value, 1);
Corresponding user space reads map[tcp], map[udp], map[icmp]
and prints protocol stats every second
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
simple .o parser and loader using BPF syscall.
.o is a standard ELF generated by LLVM backend
It parses elf file compiled by llvm .c->.o
- parses 'maps' section and creates maps via BPF syscall
- parses 'license' section and passes it to syscall
- parses elf relocations for BPF maps and adjusts BPF_LD_IMM64 insns
by storing map_fd into insn->imm and marking such insns as BPF_PSEUDO_MAP_FD
- loads eBPF programs via BPF syscall
One ELF file can contain multiple BPF programs.
int load_bpf_file(char *path);
populates prog_fd[] and map_fd[] with FDs received from bpf syscall
bpf_helpers.h - helper functions available to eBPF programs written in C
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
this socket filter example does:
- creates arraymap in kernel with key 4 bytes and value 8 bytes
- loads eBPF program which assumes that packet is IPv4 and loads one byte of
IP->proto from the packet and uses it as a key in a map
r0 = skb->data[ETH_HLEN + offsetof(struct iphdr, protocol)];
*(u32*)(fp - 4) = r0;
value = bpf_map_lookup_elem(map_fd, fp - 4);
if (value)
(*(u64*)value) += 1;
- attaches this program to raw socket
- every second user space reads map[IPPROTO_TCP], map[IPPROTO_UDP], map[IPPROTO_ICMP]
to see how many packets of given protocol were seen on loopback interface
Usage:
$sudo samples/bpf/sock_example
TCP 0 UDP 0 ICMP 0 packets
TCP 187600 UDP 0 ICMP 4 packets
TCP 376504 UDP 0 ICMP 8 packets
TCP 563116 UDP 0 ICMP 12 packets
TCP 753144 UDP 0 ICMP 16 packets
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
proper types and function helpers are ready. Use them in verifier testsuite.
Remove temporary stubs
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
. check error conditions and sanity of hash and array map APIs
. check large maps (that kernel gracefully switches to vmalloc from kmalloc)
. check multi-process parallel access and stress test
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- add a test specifically targeting verifier state pruning.
It checks state propagation between registers, storing that
state into stack and state pruning algorithm recognizing
equivalent stack and register states.
- add summary line to spot failures easier
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
while comparing for verifier state equivalency the comparison
was missing a check for uninitialized register.
Make sure it does so and add a testcase.
Fixes: f1bca824da ("bpf: add search pruning optimization to verifier")
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking updates from David Miller:
"Most notable changes in here:
1) By far the biggest accomplishment, thanks to a large range of
contributors, is the addition of multi-send for transmit. This is
the result of discussions back in Chicago, and the hard work of
several individuals.
Now, when the ->ndo_start_xmit() method of a driver sees
skb->xmit_more as true, it can choose to defer the doorbell
telling the driver to start processing the new TX queue entires.
skb->xmit_more means that the generic networking is guaranteed to
call the driver immediately with another SKB to send.
There is logic added to the qdisc layer to dequeue multiple
packets at a time, and the handling mis-predicted offloads in
software is now done with no locks held.
Finally, pktgen is extended to have a "burst" parameter that can
be used to test a multi-send implementation.
Several drivers have xmit_more support: i40e, igb, ixgbe, mlx4,
virtio_net
Adding support is almost trivial, so export more drivers to
support this optimization soon.
I want to thank, in no particular or implied order, Jesper
Dangaard Brouer, Eric Dumazet, Alexander Duyck, Tom Herbert, Jamal
Hadi Salim, John Fastabend, Florian Westphal, Daniel Borkmann,
David Tat, Hannes Frederic Sowa, and Rusty Russell.
2) PTP and timestamping support in bnx2x, from Michal Kalderon.
3) Allow adjusting the rx_copybreak threshold for a driver via
ethtool, and add rx_copybreak support to enic driver. From
Govindarajulu Varadarajan.
4) Significant enhancements to the generic PHY layer and the bcm7xxx
driver in particular (EEE support, auto power down, etc.) from
Florian Fainelli.
5) Allow raw buffers to be used for flow dissection, allowing drivers
to determine the optimal "linear pull" size for devices that DMA
into pools of pages. The objective is to get exactly the
necessary amount of headers into the linear SKB area pre-pulled,
but no more. The new interface drivers use is eth_get_headlen().
From WANG Cong, with driver conversions (several had their own
by-hand duplicated implementations) by Alexander Duyck and Eric
Dumazet.
6) Support checksumming more smoothly and efficiently for
encapsulations, and add "foo over UDP" facility. From Tom
Herbert.
7) Add Broadcom SF2 switch driver to DSA layer, from Florian
Fainelli.
8) eBPF now can load programs via a system call and has an extensive
testsuite. Alexei Starovoitov and Daniel Borkmann.
9) Major overhaul of the packet scheduler to use RCU in several major
areas such as the classifiers and rate estimators. From John
Fastabend.
10) Add driver for Intel FM10000 Ethernet Switch, from Alexander
Duyck.
11) Rearrange TCP_SKB_CB() to reduce cache line misses, from Eric
Dumazet.
12) Add Datacenter TCP congestion control algorithm support, From
Florian Westphal.
13) Reorganize sk_buff so that __copy_skb_header() is significantly
faster. From Eric Dumazet"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1558 commits)
netlabel: directly return netlbl_unlabel_genl_init()
net: add netdev_txq_bql_{enqueue, complete}_prefetchw() helpers
net: description of dma_cookie cause make xmldocs warning
cxgb4: clean up a type issue
cxgb4: potential shift wrapping bug
i40e: skb->xmit_more support
net: fs_enet: Add NAPI TX
net: fs_enet: Remove non NAPI RX
r8169:add support for RTL8168EP
net_sched: copy exts->type in tcf_exts_change()
wimax: convert printk to pr_foo()
af_unix: remove 0 assignment on static
ipv6: Do not warn for informational ICMP messages, regardless of type.
Update Intel Ethernet Driver maintainers list
bridge: Save frag_max_size between PRE_ROUTING and POST_ROUTING
tipc: fix bug in multicast congestion handling
net: better IFF_XMIT_DST_RELEASE support
net/mlx4_en: remove NETDEV_TX_BUSY
3c59x: fix bad split of cpu_to_le32(pci_map_single())
net: bcmgenet: fix Tx ring priority programming
...
add 4 extra tests to cover jump verification better
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1.
the library includes a trivial set of BPF syscall wrappers:
int bpf_create_map(int key_size, int value_size, int max_entries);
int bpf_update_elem(int fd, void *key, void *value);
int bpf_lookup_elem(int fd, void *key, void *value);
int bpf_delete_elem(int fd, void *key);
int bpf_get_next_key(int fd, void *key, void *next_key);
int bpf_prog_load(enum bpf_prog_type prog_type,
const struct sock_filter_int *insns, int insn_len,
const char *license);
bpf_prog_load() stores verifier log into global bpf_log_buf[] array
and BPF_*() macros to build instructions
2.
test stubs configure eBPF infra with 'unspec' map and program types.
These are fake types used by user space testsuite only.
3.
verifier tests valid and invalid programs and expects predefined
error log messages from kernel.
40 tests so far.
$ sudo ./test_verifier
#0 add+sub+mul OK
#1 unreachable OK
#2 unreachable2 OK
#3 out of range jump OK
#4 out of range jump2 OK
#5 test1 ld_imm64 OK
...
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit e80d666 "flagday: kill pt_regs argument of do_fork()", the
arguments to do_fork() changed.
The example code in jprobe_example.c was not updated to match, so the
arguments inside the jprobe handler do not match reality.
Fix it by updating the arguments to match do_fork(). While we're at it
use pr_info() for brevity, and print stack_start as well for interest.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Strings should be copied with strlcpy instead of strncpy when they will
later be printed via %s. This guarantees that they terminate with a
NUL '\0' character and do not run pass the end of the allocated string.
This is only for sample code, but it should stil represent a good
role model.
Link: http://lkml.kernel.org/p/51C2E204.1080501@huawei.com
Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the __field() macro in TRACE_EVENT is only good for primitive
values, such as integers and pointers, but it fails on complex data types
such as structures or unions. This is because the __field() macro
determines if the variable is signed or not with the test of:
(((type)(-1)) < (type)1)
Unfortunately, that fails when type is a structure.
Since trace events should support structures as fields a new macro
is created for such a case called __field_struct() which acts exactly
the same as __field() does but it does not do the signed type check
and just uses a constant false for that answer.
Cc: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In line with practice for module parameters, we're adding a build-time
check that sysfs files aren't world-writable.
Cc: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The Makefile is designed to use the host toolchain so it may be unsafe
to build the tests if the kernel has been configured and built for
another architecture. This fixes a build problem when the kernel has
been configured and built for the MIPS architecture but the host is not
MIPS (cross-compiled). The MIPS syscalls are only defined if one of the
following is true:
1) _MIPS_SIM == _MIPS_SIM_ABI64
2) _MIPS_SIM == _MIPS_SIM_ABI32
3) _MIPS_SIM == _MIPS_SIM_NABI32
Of course, none of these make sense on a non-MIPS toolchain and the
following build problem occurs when building on a non-MIPS host.
linux/usr/include/linux/kexec.h:50: userspace cannot reference function or variable defined in the kernel
samples/seccomp/bpf-direct.c: In function `emulator':
samples/seccomp/bpf-direct.c:76:17: error: `__NR_write' undeclared (first use in this function)
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously, example_init() leaked a kset if any of the object creations
failed. This fixes the leak by calling kset_unregister() in the error
path.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch enhances the type safety for the kfifo API. It is now safe
to put const data into a non const FIFO and the API will now generate a
compiler warning when reading from the fifo where the destination
address is pointing to a const variable.
As a side effect the kfifo_put() does now expect the value of an element
instead a pointer to the element. This was suggested Russell King. It
make the handling of the kfifo_put easier since there is no need to
create a helper variable for getting the address of a pointer or to pass
integers of different sizes.
IMHO the API break is okay, since there are currently only six users of
kfifo_put().
The code is also cleaner by kicking out the "if (0)" expressions.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull Tile arch updates from Chris Metcalf:
"These changes bring in a bunch of new functionality that has been
maintained internally at Tilera over the last year, plus other stray
bits of work that I've taken into the tile tree from other folks.
The changes include some PCI root complex work, interrupt-driven
console support, support for performing fast-path unaligned data
fixups by kernel-based JIT code generation, CONFIG_PREEMPT support,
vDSO support for gettimeofday(), a serial driver for the tilegx
on-chip UART, KGDB support, more optimized string routines, support
for ftrace and kprobes, improved ASLR, and many bug fixes.
We also remove support for the old TILE64 chip, which is no longer
buildable"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (85 commits)
tile: refresh tile defconfig files
tile: rework <asm/cmpxchg.h>
tile PCI RC: make default consistent DMA mask 32-bit
tile: add null check for kzalloc in tile/kernel/setup.c
tile: make __write_once a synonym for __read_mostly
tile: remove support for TILE64
tile: use asm-generic/bitops/builtin-*.h
tile: eliminate no-op "noatomichash" boot argument
tile: use standard tile_bundle_bits type in traps.c
tile: simplify code referencing hypervisor API addresses
tile: change <asm/system.h> to <asm/switch_to.h> in comments
tile: mark pcibios_init() as __init
tile: check for correct compiler earlier in asm-offsets.c
tile: use standard 'generic-y' model for <asm/hw_irq.h>
tile: use asm-generic version of <asm/local64.h>
tile PCI RC: add comment about "PCI hole" problem
tile: remove DEBUG_EXTRA_FLAGS kernel config option
tile: add virt_to_kpte() API and clean up and document behavior
tile: support FRAME_POINTER
tile: support reporting Tilera hypervisor statistics
...
