Extend urandom_read helper binary to include USDTs of 4 combinations:
semaphore/semaphoreless (refcounted and non-refcounted) and based in
executable or shared library. We also extend urandom_read with ability
to report it's own PID to parent process and wait for parent process to
ready itself up for tracing urandom_read. We utilize popen() and
underlying pipe properties for proper signaling.
Once urandom_read is ready, we add few tests to validate that libbpf's
USDT attachment handles all the above combinations of semaphore (or lack
of it) and static or shared library USDTs. Also, we validate that libbpf
handles shared libraries both with PID filter and without one (i.e., -1
for PID argument).
Having the shared library case tested with and without PID is important
because internal logic differs on kernels that don't support BPF
cookies. On such older kernels, attaching to USDTs in shared libraries
without specifying concrete PID doesn't work in principle, because it's
impossible to determine shared library's load address to derive absolute
IPs for uprobe attachments. Without absolute IPs, it's impossible to
perform correct look up of USDT spec based on uprobe's absolute IP (the
only kind available from BPF at runtime). This is not the problem on
newer kernels with BPF cookie as we don't need IP-to-ID lookup because
BPF cookie value *is* spec ID.
So having those two situations as separate subtests is good because
libbpf CI is able to test latest selftests against old kernels (e.g.,
4.9 and 5.5), so we'll be able to disable PID-less shared lib attachment
for old kernels, but will still leave PID-specific one enabled to validate
this legacy logic is working correctly.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-8-andrii@kernel.org
Add semaphore-based USDT to test_progs itself and write basic tests to
valicate both auto-attachment and manual attachment logic, as well as
BPF-side functionality.
Also add subtests to validate that libbpf properly deduplicates USDT
specs and handles spec overflow situations correctly, as well as proper
"rollback" of partially-attached multi-spec USDT.
BPF-side of selftest intentionally consists of two files to validate
that usdt.bpf.h header can be included from multiple source code files
that are subsequently linked into final BPF object file without causing
any symbol duplication or other issues. We are validating that __weak
maps and bpf_usdt_xxx() API functions defined in usdt.bpf.h do work as
intended.
USDT selftests utilize sys/sdt.h header that on Ubuntu systems comes
from systemtap-sdt-devel package. But to simplify everyone's life,
including CI but especially casual contributors to bpf/bpf-next that
are trying to build selftests, I've checked in sys/sdt.h header from [0]
directly. This way it will work on all architectures and distros without
having to figure it out for every relevant combination and adding any
extra implicit package dependencies.
[0] https://sourceware.org/git?p=systemtap.git;a=blob_plain;f=includes/sys/sdt.h;h=ca0162b4dc57520b96638c8ae79ad547eb1dd3a1;hb=HEAD
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-7-andrii@kernel.org
Add x86/x86_64-specific USDT argument specification parsing. Each
architecture will require their own logic, as all this is arch-specific
assembly-based notation. Architectures that libbpf doesn't support for
USDTs will pr_warn() with specific error and return -ENOTSUP.
We use sscanf() as a very powerful and easy to use string parser. Those
spaces in sscanf's format string mean "skip any whitespaces", which is
pretty nifty (and somewhat little known) feature.
All this was tested on little-endian architecture, so bit shifts are
probably off on big-endian, which our CI will hopefully prove.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-6-andrii@kernel.org
Last part of architecture-agnostic user-space USDT handling logic is to
set up BPF spec and, optionally, IP-to-ID maps from user-space.
usdt_manager performs a compact spec ID allocation to utilize
fixed-sized BPF maps as efficiently as possible. We also use hashmap to
deduplicate USDT arg spec strings and map identical strings to single
USDT spec, minimizing the necessary BPF map size. usdt_manager supports
arbitrary sequences of attachment and detachment, both of the same USDT
and multiple different USDTs and internally maintains a free list of
unused spec IDs. bpf_link_usdt's logic is extended with proper setup and
teardown of this spec ID free list and supporting BPF maps.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-5-andrii@kernel.org
Implement architecture-agnostic parts of USDT parsing logic. The code is
the documentation in this case, it's futile to try to succinctly
describe how USDT parsing is done in any sort of concreteness. But
still, USDTs are recorded in special ELF notes section (.note.stapsdt),
where each USDT call site is described separately. Along with USDT
provider and USDT name, each such note contains USDT argument
specification, which uses assembly-like syntax to describe how to fetch
value of USDT argument. USDT arg spec could be just a constant, or
a register, or a register dereference (most common cases in x86_64), but
it technically can be much more complicated cases, like offset relative
to global symbol and stuff like that. One of the later patches will
implement most common subset of this for x86 and x86-64 architectures,
which seems to handle a lot of real-world production application.
USDT arg spec contains a compact encoding allowing usdt.bpf.h from
previous patch to handle the above 3 cases. Instead of recording which
register might be needed, we encode register's offset within struct
pt_regs to simplify BPF-side implementation. USDT argument can be of
different byte sizes (1, 2, 4, and 8) and signed or unsigned. To handle
this, libbpf pre-calculates necessary bit shifts to do proper casting
and sign-extension in a short sequences of left and right shifts.
The rest is in the code with sometimes extensive comments and references
to external "documentation" for USDTs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-4-andrii@kernel.org
Wire up libbpf USDT support APIs without yet implementing all the
nitty-gritty details of USDT discovery, spec parsing, and BPF map
initialization.
User-visible user-space API is simple and is conceptually very similar
to uprobe API.
bpf_program__attach_usdt() API allows to programmatically attach given
BPF program to a USDT, specified through binary path (executable or
shared lib), USDT provider and name. Also, just like in uprobe case, PID
filter is specified (0 - self, -1 - any process, or specific PID).
Optionally, USDT cookie value can be specified. Such single API
invocation will try to discover given USDT in specified binary and will
use (potentially many) BPF uprobes to attach this program in correct
locations.
Just like any bpf_program__attach_xxx() APIs, bpf_link is returned that
represents this attachment. It is a virtual BPF link that doesn't have
direct kernel object, as it can consist of multiple underlying BPF
uprobe links. As such, attachment is not atomic operation and there can
be brief moment when some USDT call sites are attached while others are
still in the process of attaching. This should be taken into
consideration by user. But bpf_program__attach_usdt() guarantees that
in the case of success all USDT call sites are successfully attached, or
all the successfuly attachments will be detached as soon as some USDT
call sites failed to be attached. So, in theory, there could be cases of
failed bpf_program__attach_usdt() call which did trigger few USDT
program invocations. This is unavoidable due to multi-uprobe nature of
USDT and has to be handled by user, if it's important to create an
illusion of atomicity.
USDT BPF programs themselves are marked in BPF source code as either
SEC("usdt"), in which case they won't be auto-attached through
skeleton's <skel>__attach() method, or it can have a full definition,
which follows the spirit of fully-specified uprobes:
SEC("usdt/<path>:<provider>:<name>"). In the latter case skeleton's
attach method will attempt auto-attachment. Similarly, generic
bpf_program__attach() will have enought information to go off of for
parameterless attachment.
USDT BPF programs are actually uprobes, and as such for kernel they are
marked as BPF_PROG_TYPE_KPROBE.
Another part of this patch is USDT-related feature probing:
- BPF cookie support detection from user-space;
- detection of kernel support for auto-refcounting of USDT semaphore.
The latter is optional. If kernel doesn't support such feature and USDT
doesn't rely on USDT semaphores, no error is returned. But if libbpf
detects that USDT requires setting semaphores and kernel doesn't support
this, libbpf errors out with explicit pr_warn() message. Libbpf doesn't
support poking process's memory directly to increment semaphore value,
like BCC does on legacy kernels, due to inherent raciness and danger of
such process memory manipulation. Libbpf let's kernel take care of this
properly or gives up.
Logistically, all the extra USDT-related infrastructure of libbpf is put
into a separate usdt.c file and abstracted behind struct usdt_manager.
Each bpf_object has lazily-initialized usdt_manager pointer, which is
only instantiated if USDT programs are attempted to be attached. Closing
BPF object frees up usdt_manager resources. usdt_manager keeps track of
USDT spec ID assignment and few other small things.
Subsequent patches will fill out remaining missing pieces of USDT
initialization and setup logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-3-andrii@kernel.org
Add BPF-side implementation of libbpf-provided USDT support. This
consists of single header library, usdt.bpf.h, which is meant to be used
from user's BPF-side source code. This header is added to the list of
installed libbpf header, along bpf_helpers.h and others.
BPF-side implementation consists of two BPF maps:
- spec map, which contains "a USDT spec" which encodes information
necessary to be able to fetch USDT arguments and other information
(argument count, user-provided cookie value, etc) at runtime;
- IP-to-spec-ID map, which is only used on kernels that don't support
BPF cookie feature. It allows to lookup spec ID based on the place
in user application that triggers USDT program.
These maps have default sizes, 256 and 1024, which are chosen
conservatively to not waste a lot of space, but handling a lot of common
cases. But there could be cases when user application needs to either
trace a lot of different USDTs, or USDTs are heavily inlined and their
arguments are located in a lot of differing locations. For such cases it
might be necessary to size those maps up, which libbpf allows to do by
overriding BPF_USDT_MAX_SPEC_CNT and BPF_USDT_MAX_IP_CNT macros.
It is an important aspect to keep in mind. Single USDT (user-space
equivalent of kernel tracepoint) can have multiple USDT "call sites".
That is, single logical USDT is triggered from multiple places in user
application. This can happen due to function inlining. Each such inlined
instance of USDT invocation can have its own unique USDT argument
specification (instructions about the location of the value of each of
USDT arguments). So while USDT looks very similar to usual uprobe or
kernel tracepoint, under the hood it's actually a collection of uprobes,
each potentially needing different spec to know how to fetch arguments.
User-visible API consists of three helper functions:
- bpf_usdt_arg_cnt(), which returns number of arguments of current USDT;
- bpf_usdt_arg(), which reads value of specified USDT argument (by
it's zero-indexed position) and returns it as 64-bit value;
- bpf_usdt_cookie(), which functions like BPF cookie for USDT
programs; this is necessary as libbpf doesn't allow specifying actual
BPF cookie and utilizes it internally for USDT support implementation.
Each bpf_usdt_xxx() APIs expect struct pt_regs * context, passed into
BPF program. On kernels that don't support BPF cookie it is used to
fetch absolute IP address of the underlying uprobe.
usdt.bpf.h also provides BPF_USDT() macro, which functions like
BPF_PROG() and BPF_KPROBE() and allows much more user-friendly way to
get access to USDT arguments, if USDT definition is static and known to
the user. It is expected that majority of use cases won't have to use
bpf_usdt_arg_cnt() and bpf_usdt_arg() directly and BPF_USDT() will cover
all their needs.
Last, usdt.bpf.h is utilizing BPF CO-RE for one single purpose: to
detect kernel support for BPF cookie. If BPF CO-RE dependency is
undesirable, user application can redefine BPF_USDT_HAS_BPF_COOKIE to
either a boolean constant (or equivalently zero and non-zero), or even
point it to its own .rodata variable that can be specified from user's
application user-space code. It is important that
BPF_USDT_HAS_BPF_COOKIE is known to BPF verifier as static value (thus
.rodata and not just .data), as otherwise BPF code will still contain
bpf_get_attach_cookie() BPF helper call and will fail validation at
runtime, if not dead-code eliminated.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-2-andrii@kernel.org
attach_probe selftest fails on Debian-based distros with `failed to
resolve full path for 'libc.so.6'`. The reason is that these distros
embraced multiarch to the point where even for the "main" architecture
they store libc in /lib/<triple>.
This is configured in /etc/ld.so.conf and in theory it's possible to
replicate the loader's parsing and processing logic in libbpf, however
a much simpler solution is to just enumerate the known library paths.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220404225020.51029-1-iii@linux.ibm.com
Milan Landaverde says:
====================
With the addition of the syscall prog type we should now
be able to see feature probe info for that prog type:
$ bpftool feature probe kernel
...
eBPF program_type syscall is available
...
eBPF helpers supported for program type syscall:
...
- bpf_sys_bpf
- bpf_sys_close
And for the link types, their names should aid in
the output.
Before:
$ bpftool link show
50: type 7 prog 5042
bpf_cookie 0
pids vfsstat(394433)
After:
$ bpftool link show
57: perf_event prog 5058
bpf_cookie 0
pids vfsstat(394725)
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
The script for checking that various lists of types in bpftool remain in
sync with the UAPI BPF header uses a regex to parse enum bpf_prog_type.
If this enum contains a set of values different from the list of program
types in bpftool, it complains.
This script should have reported the addition, some time ago, of the new
BPF_PROG_TYPE_SYSCALL, which was not reported to bpftool's program types
list. It failed to do so, because it failed to parse that new type from
the enum. This is because the new value, in the BPF header, has an
explicative comment on the same line, and the regex does not support
that.
Let's update the script to support parsing enum values when they have
comments on the same line.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220404140944.64744-1-quentin@isovalent.com
Users of the xdp_sample_user infra should be explicitly linked
with the standard math library (`-lm`). Otherwise, the following
happens:
/usr/bin/ld: xdp_sample_user.c:(.text+0x59fc): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x5a0d): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x5adc): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x5b01): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x5c1e): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x5c43): undefined reference to `ceil
[...]
That happened previously, so there's a block of linkage flags in the
Makefile. xdp_router_ipv4 has been transferred to this infra quite
recently, but hasn't been added to it. Fix.
Fixes: 85bf1f5169 ("samples: bpf: Convert xdp_router_ipv4 to XDP samples helper")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220404115451.1116478-1-alexandr.lobakin@intel.com
Alan Maguire says:
====================
This patch series focuses on supporting name-based attach - similar
to that supported for kprobes - for uprobe BPF programs.
Currently attach for such probes is done by determining the offset
manually, so the aim is to try and mimic the simplicity of kprobe
attach, making use of uprobe opts to specify a name string.
Patch 1 supports expansion of the binary_path argument used for
bpf_program__attach_uprobe_opts(), allowing it to determine paths
for programs and shared objects automatically, allowing for
specification of "libc.so.6" rather than the full path
"/usr/lib64/libc.so.6".
Patch 2 adds the "func_name" option to allow uprobe attach by
name; the mechanics are described there.
Having name-based support allows us to support auto-attach for
uprobes; patch 3 adds auto-attach support while attempting
to handle backwards-compatibility issues that arise. The format
supported is
u[ret]probe/binary_path:[raw_offset|function[+offset]]
For example, to attach to libc malloc:
SEC("uprobe//usr/lib64/libc.so.6:malloc")
..or, making use of the path computation mechanisms introduced in patch 1
SEC("uprobe/libc.so.6:malloc")
Finally patch 4 add tests to the attach_probe selftests covering
attach by name, with patch 5 covering skeleton auto-attach.
Changes since v4 [1]:
- replaced strtok_r() usage with copying segments from static char *; avoids
unneeded string allocation (Andrii, patch 1)
- switched to using access() instead of stat() when checking path-resolved
binary (Andrii, patch 1)
- removed computation of .plt offset for instrumenting shared library calls
within binaries. Firstly it proved too brittle, and secondly it was somewhat
unintuitive in that this form of instrumentation did not support function+offset
as the "local function in binary" and "shared library function in shared library"
cases did. We can still instrument library calls, just need to do it in the
library .so (patch 2)
- added binary path logging in cases where it was missing (Andrii, patch 2)
- avoid strlen() calcuation in checking name match (Andrii, patch 2)
- reword comments for func_name option (Andrii, patch 2)
- tightened SEC() name validation to support "u[ret]probe" and fail on other
permutations that do not support auto-attach (i.e. have u[ret]probe/binary_path:func
format (Andrii, patch 3)
- fixed selftests to fail independently rather than skip remainder on failure
(Andrii, patches 4,5)
Changes since v3 [2]:
- reworked variable naming to fit better with libbpf conventions
(Andrii, patch 2)
- use quoted binary path in log messages (Andrii, patch 2)
- added path determination mechanisms using LD_LIBRARY_PATH/PATH and
standard locations (patch 1, Andrii)
- changed section lookup to be type+name (if name is specified) to
simplify use cases (patch 2, Andrii)
- fixed .plt lookup scheme to match symbol table entries with .plt
index via the .rela.plt table; also fix the incorrect assumption
that the code in the .plt that does library linking is the same
size as .plt entries (it just happens to be on x86_64)
- aligned with pluggable section support such that uprobe SEC() names
that do not conform to auto-attach format do not cause skeleton load
failure (patch 3, Andrii)
- no longer need to look up absolute path to libraries used by test_progs
since we have mechanism to determine path automatically
- replaced CHECK()s with ASSERT*()s for attach_probe test (Andrii, patch 4)
- added auto-attach selftests also (Andrii, patch 5)
Changes since RFC [3]:
- used "long" for addresses instead of ssize_t (Andrii, patch 1).
- used gelf_ interfaces to avoid assumptions about 64-bit
binaries (Andrii, patch 1)
- clarified string matching in symbol table lookups
(Andrii, patch 1)
- added support for specification of shared object functions
in a non-shared object binary. This approach instruments
the Procedure Linking Table (PLT) - malloc@PLT.
- changed logic in symbol search to check dynamic symbol table
first, then fall back to symbol table (Andrii, patch 1).
- modified auto-attach string to require "/" separator prior
to path prefix i.e. uprobe//path/to/binary (Andrii, patch 2)
- modified auto-attach string to use ':' separator (Andrii,
patch 2)
- modified auto-attach to support raw offset (Andrii, patch 2)
- modified skeleton attach to interpret -ESRCH errors as
a non-fatal "unable to auto-attach" (Andrii suggested
-EOPNOTSUPP but my concern was it might collide with other
instances where that value is returned and reflects a
failure to attach a to-be-expected attachment rather than
skip a program that does not present an auto-attachable
section name. Admittedly -EOPNOTSUPP seems a more natural
value here).
- moved library path retrieval code to trace_helpers (Andrii,
patch 3)
[1] https://lore.kernel.org/bpf/1647000658-16149-1-git-send-email-alan.maguire@oracle.com/
[2] https://lore.kernel.org/bpf/1643645554-28723-1-git-send-email-alan.maguire@oracle.com/
[3] https://lore.kernel.org/bpf/1642678950-19584-1-git-send-email-alan.maguire@oracle.com/
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
add tests that verify attaching by name for
1. local functions in a program
2. library functions in a shared object
...succeed for uprobe and uretprobes using new "func_name"
option for bpf_program__attach_uprobe_opts(). Also verify
auto-attach works where uprobe, path to binary and function
name are specified, but fails with -EOPNOTSUPP with a SEC
name that does not specify binary path/function.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648654000-21758-5-git-send-email-alan.maguire@oracle.com
Now that u[ret]probes can use name-based specification, it makes
sense to add support for auto-attach based on SEC() definition.
The format proposed is
SEC("u[ret]probe/binary:[raw_offset|[function_name[+offset]]")
For example, to trace malloc() in libc:
SEC("uprobe/libc.so.6:malloc")
...or to trace function foo2 in /usr/bin/foo:
SEC("uprobe//usr/bin/foo:foo2")
Auto-attach is done for all tasks (pid -1). prog can be an absolute
path or simply a program/library name; in the latter case, we use
PATH/LD_LIBRARY_PATH to resolve the full path, falling back to
standard locations (/usr/bin:/usr/sbin or /usr/lib64:/usr/lib) if
the file is not found via environment-variable specified locations.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648654000-21758-4-git-send-email-alan.maguire@oracle.com
kprobe attach is name-based, using lookups of kallsyms to translate
a function name to an address. Currently uprobe attach is done
via an offset value as described in [1]. Extend uprobe opts
for attach to include a function name which can then be converted
into a uprobe-friendly offset. The calcualation is done in
several steps:
1. First, determine the symbol address using libelf; this gives us
the offset as reported by objdump
2. If the function is a shared library function - and the binary
provided is a shared library - no further work is required;
the address found is the required address
3. Finally, if the function is local, subtract the base address
associated with the object, retrieved from ELF program headers.
The resultant value is then added to the func_offset value passed
in to specify the uprobe attach address. So specifying a func_offset
of 0 along with a function name "printf" will attach to printf entry.
The modes of operation supported are then
1. to attach to a local function in a binary; function "foo1" in
"/usr/bin/foo"
2. to attach to a shared library function in a shared library -
function "malloc" in libc.
[1] https://www.kernel.org/doc/html/latest/trace/uprobetracer.html
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648654000-21758-3-git-send-email-alan.maguire@oracle.com
bpf_program__attach_uprobe_opts() requires a binary_path argument
specifying binary to instrument. Supporting simply specifying
"libc.so.6" or "foo" should be possible too.
Library search checks LD_LIBRARY_PATH, then /usr/lib64, /usr/lib.
This allows users to run BPF programs prefixed with
LD_LIBRARY_PATH=/path2/lib while still searching standard locations.
Similarly for non .so files, we check PATH and /usr/bin, /usr/sbin.
Path determination will be useful for auto-attach of BPF uprobe programs
using SEC() definition.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648654000-21758-2-git-send-email-alan.maguire@oracle.com
Currently, when we run test_progs with just executable file name, for
example 'PATH=. test_progs-no_alu32', cd_flavor_subdir() will not check
if test_progs is running as a flavored test runner and switch into
corresponding sub-directory.
This will cause test_progs-no_alu32 executed by the
'PATH=. test_progs-no_alu32' command to run in the wrong directory and
load the wrong BPF objects.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220403135245.1713283-1-ytcoode@gmail.com
Return boolean values ("true" or "false") instead of 1 or 0 from bool
functions. This fixes the following warnings from coccicheck:
./tools/testing/selftests/bpf/progs/test_xdp_noinline.c:567:9-10: WARNING:
return of 0/1 in function 'get_packet_dst' with return type bool
./tools/testing/selftests/bpf/progs/test_l4lb_noinline.c:221:9-10: WARNING:
return of 0/1 in function 'get_packet_dst' with return type bool
Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/1648779354-14700-1-git-send-email-baihaowen@meizu.com
Since commit 6521f89170 ("namei: prepare for idmapped mounts")
vfs_link's prototype was changed, the kprobe definition in
profiler selftest in turn wasn't updated. The result is that all
argument after the first are now stored in different registers. This
means that self-test has been broken ever since. Fix it by updating the
kprobe definition accordingly.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220331140949.1410056-1-nborisov@suse.com
The test fails:
# ./test_offload.py
[...]
Test bpftool bound info reporting (own ns)...
FAIL: 3 BPF maps loaded, expected 2
File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 1177, in <module>
check_dev_info(False, "")
File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 645, in check_dev_info
maps = bpftool_map_list(expected=2, ns=ns)
File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 190, in bpftool_map_list
fail(True, "%d BPF maps loaded, expected %d" %
File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 86, in fail
tb = "".join(traceback.extract_stack().format())
Some base maps do not have names and they cannot be added due to compatibility
with older kernels, see [0]. So, just skip the unnamed maps.
[0] https://lore.kernel.org/bpf/CAEf4BzY66WPKQbDe74AKZ6nFtZjq5e+G3Ji2egcVytB9R6_sGQ@mail.gmail.com/
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220329081100.9705-1-ykaliuta@redhat.com
Add test case to enusre that the caller and callee's fp offsets are
correct during tail call (mainly asserting for arm64 JIT).
Tested on both big-endian and little-endian arm64 qemu, result:
test_bpf: Summary: 1026 PASSED, 0 FAILED, [1014/1014 JIT'ed]
test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed]
test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220321152852.2334294-6-xukuohai@huawei.com
The current BPF store/load instruction is translated by the JIT into two
instructions. The first instruction moves the immediate offset into a
temporary register. The second instruction uses this temporary register
to do the real store/load.
In fact, arm64 supports addressing with immediate offsets. So This patch
introduces optimization that uses arm64 str/ldr instruction with immediate
offset when the offset fits.
Example of generated instuction for r2 = *(u64 *)(r1 + 0):
without optimization:
mov x10, 0
ldr x1, [x0, x10]
with optimization:
ldr x1, [x0, 0]
If the offset is negative, or is not aligned correctly, or exceeds max
value, rollback to the use of temporary register.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220321152852.2334294-3-xukuohai@huawei.com
This patch introduces ldr/str with immediate offset support to simplify
the JIT implementation of BPF LDX/STX instructions on arm64. Although
arm64 ldr/str immediate is available in pre-index, post-index and
unsigned offset forms, the unsigned offset form is sufficient for BPF,
so this patch only adds this type.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220321152852.2334294-2-xukuohai@huawei.com
Pull more networking updates from Jakub Kicinski:
"Networking fixes and rethook patches.
Features:
- kprobes: rethook: x86: replace kretprobe trampoline with rethook
Current release - regressions:
- sfc: avoid null-deref on systems without NUMA awareness in the new
queue sizing code
Current release - new code bugs:
- vxlan: do not feed vxlan_vnifilter_dump_dev with non-vxlan devices
- eth: lan966x: fix null-deref on PHY pointer in timestamp ioctl when
interface is down
Previous releases - always broken:
- openvswitch: correct neighbor discovery target mask field in the
flow dump
- wireguard: ignore v6 endpoints when ipv6 is disabled and fix a leak
- rxrpc: fix call timer start racing with call destruction
- rxrpc: fix null-deref when security type is rxrpc_no_security
- can: fix UAF bugs around echo skbs in multiple drivers
Misc:
- docs: move netdev-FAQ to the 'process' section of the
documentation"
* tag 'net-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (57 commits)
vxlan: do not feed vxlan_vnifilter_dump_dev with non vxlan devices
openvswitch: Add recirc_id to recirc warning
rxrpc: fix some null-ptr-deref bugs in server_key.c
rxrpc: Fix call timer start racing with call destruction
net: hns3: fix software vlan talbe of vlan 0 inconsistent with hardware
net: hns3: fix the concurrency between functions reading debugfs
docs: netdev: move the netdev-FAQ to the process pages
docs: netdev: broaden the new vs old code formatting guidelines
docs: netdev: call out the merge window in tag checking
docs: netdev: add missing back ticks
docs: netdev: make the testing requirement more stringent
docs: netdev: add a question about re-posting frequency
docs: netdev: rephrase the 'should I update patchwork' question
docs: netdev: rephrase the 'Under review' question
docs: netdev: shorten the name and mention msgid for patch status
docs: netdev: note that RFC postings are allowed any time
docs: netdev: turn the net-next closed into a Warning
docs: netdev: move the patch marking section up
docs: netdev: minor reword
docs: netdev: replace references to old archives
...
Pull crypto fixes from Herbert Xu:
- Missing Kconfig dependency on arm that leads to boot failure
- x86 SLS fixes
- Reference leak in the stm32 driver
* tag 'v5.18-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: x86/sm3 - Fixup SLS
crypto: x86/poly1305 - Fixup SLS
crypto: x86/chacha20 - Avoid spurious jumps to other functions
crypto: stm32 - fix reference leak in stm32_crc_remove
crypto: arm/aes-neonbs-cbc - Select generic cbc and aes
When hitting the recirculation limit, the kernel would currently log
something like this:
[ 58.586597] openvswitch: ovs-system: deferred action limit reached, drop recirc action
Which isn't all that useful to debug as we only have the interface name
to go on but can't track it down to a specific flow.
With this change, we now instead get:
[ 58.586597] openvswitch: ovs-system: deferred action limit reached, drop recirc action (recirc_id=0x9e)
Which can now be correlated with the flow entries from OVS.
Suggested-by: Frode Nordahl <frode.nordahl@canonical.com>
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Tested-by: Stephane Graber <stgraber@ubuntu.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/20220330194244.3476544-1-stgraber@ubuntu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Marc Kleine-Budde says:
====================
pull-request: can 2022-03-31
The first patch is by Oliver Hartkopp and fixes MSG_PEEK feature in
the CAN ISOTP protocol (broken in net-next for v5.18 only).
Tom Rix's patch for the mcp251xfd driver fixes the propagation of an
error value in case of an error.
A patch by me for the m_can driver fixes a use-after-free in the xmit
handler for m_can IP cores v3.0.x.
Hangyu Hua contributes 3 patches fixing the same double free in the
error path of the xmit handler in the ems_usb, usb_8dev and mcba_usb
USB CAN driver.
Pavel Skripkin contributes a patch for the mcba_usb driver to properly
check the endpoint type.
The last patch is by me and fixes a mem leak in the gs_usb, which was
introduced in net-next for v5.18.
* tag 'linux-can-fixes-for-5.18-20220331' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
can: gs_usb: gs_make_candev(): fix memory leak for devices with extended bit timing configuration
can: mcba_usb: properly check endpoint type
can: mcba_usb: mcba_usb_start_xmit(): fix double dev_kfree_skb in error path
can: usb_8dev: usb_8dev_start_xmit(): fix double dev_kfree_skb() in error path
can: ems_usb: ems_usb_start_xmit(): fix double dev_kfree_skb() in error path
can: m_can: m_can_tx_handler(): fix use after free of skb
can: mcp251xfd: mcp251xfd_register_get_dev_id(): fix return of error value
can: isotp: restore accidentally removed MSG_PEEK feature
====================
Link: https://lore.kernel.org/r/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The rxrpc_call struct has a timer used to handle various timed events
relating to a call. This timer can get started from the packet input
routines that are run in softirq mode with just the RCU read lock held.
Unfortunately, because only the RCU read lock is held - and neither ref or
other lock is taken - the call can start getting destroyed at the same time
a packet comes in addressed to that call. This causes the timer - which
was already stopped - to get restarted. Later, the timer dispatch code may
then oops if the timer got deallocated first.
Fix this by trying to take a ref on the rxrpc_call struct and, if
successful, passing that ref along to the timer. If the timer was already
running, the ref is discarded.
The timer completion routine can then pass the ref along to the call's work
item when it queues it. If the timer or work item where already
queued/running, the extra ref is discarded.
Fixes: a158bdd324 ("rxrpc: Fix call timeouts")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2022-March/005073.html
Link: https://lore.kernel.org/r/164865115696.2943015.11097991776647323586.stgit@warthog.procyon.org.uk
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When user delete vlan 0, as driver will not delete vlan 0 for hardware in
function hclge_set_vlan_filter_hw(), so vlan 0 in software vlan talbe should
not be deleted.
Fixes: fe4144d47e ("net: hns3: sync VLAN filter entries when kill VLAN ID failed")
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the debugfs mechanism is that all functions share a
global variable to save the pointer for obtaining data. When
different functions concurrently access the same file node,
repeated release exceptions occur. Therefore, the granularity
of the pointer for storing the obtained data is adjusted to be
private for each function.
Fixes: 5e69ea7ee2 ("net: hns3: refactor the debugfs process")
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Jakub Kicinski says:
====================
docs: update and move the netdev-FAQ
A section of documentation for tree-specific process quirks had
been created a while back. There's only one tree in it, so far,
the tip tree, but the contents seem to answer similar questions
as we answer in the netdev-FAQ. Move the netdev-FAQ.
Take this opportunity to touch up and update a few sections.
v3: remove some confrontational? language from patch 7
v2: remove non-git in patch 3
add patch 5
====================
Link: https://lore.kernel.org/r/20220330042505.2902770-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The documentation for the tip tree is really in quite a similar
spirit to the netdev-FAQ. Move the netdev-FAQ to the process docs
as well.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
