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In [1], Will raised a potential issue that the cfg80211 code,
which does (from a locking perspective)
rtnl_lock()
wiphy_lock()
rtnl_unlock()
might be suspectible to ABBA deadlocks, because rtnl_unlock()
calls netdev_run_todo(), which might end up calling rtnl_lock()
again, which could then deadlock (see the comment in the code
added here for the scenario).
Some back and forth and thinking ensued, but clearly this can't
happen if the net_todo_list is empty at the rtnl_unlock() here.
Clearly, the code here cannot actually put an entry on it, and
all other users of rtnl_unlock() will empty it since that will
always go through netdev_run_todo(), emptying the list.
So the only other way to get there would be to add to the list
and then unlock the RTNL without going through rtnl_unlock(),
which is only possible through __rtnl_unlock(). However, this
isn't exported and not used in many places, and none of them
seem to be able to unregister before using it.
Therefore, add a WARN_ON() in the code to ensure this invariant
won't be broken, so that the cfg80211 (or any similar) code
stays safe.
[1] https://lore.kernel.org/r/Yjzpo3TfZxtKPMAG@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20220404113847.0ee02e4a70da.Ic73d206e217db20fd22dcec14fe5442ca732804b@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The setting of i here
err_nexthop6_group_get:
i = nrt6;
Is redundant, i is already nrt6. So remove
this statement.
The for loop for the unwinding
err_rt6_create:
for (i--; i >= 0; i--) {
Is equivelent to
for (; i > 0; i--) {
Two consecutive labels can be reduced to one.
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20220402121516.2750284-1-trix@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Andrii Nakryiko says:
====================
Add libbpf support for USDT (User Statically-Defined Tracing) probes.
USDTs is important part of tracing, and BPF, ecosystem, widely used in
mission-critical production applications for observability, performance
analysis, and debugging.
And while USDTs themselves are pretty complicated abstraction built on top of
uprobes, for end-users USDT is as natural a primitive as uprobes themselves.
And thus it's important for libbpf to provide best possible user experience
when it comes to build tracing applications relying on USDTs.
USDTs historically presented a lot of challenges for libbpf's no
compilation-on-the-fly general approach to BPF tracing. BCC utilizes power of
on-the-fly source code generation and compilation using its embedded Clang
toolchain, which was impractical for more lightweight and thus more rigid
libbpf-based approach. But still, with enough diligence and BPF cookies it's
possible to implement USDT support that feels as natural as tracing any
uprobe.
This patch set is the culmination of such effort to add libbpf USDT support
following the spirit and philosophy of BPF CO-RE (even though it's not
inherently relying on BPF CO-RE much, see patch #1 for some notes regarding
this). Each respective patch has enough details and explanations, so I won't
go into details here.
In the end, I think the overall usability of libbpf's USDT support *exceeds*
the status quo set by BCC due to the elimination of awkward runtime USDT
supporting code generation. It also exceeds BCC's capabilities due to the use
of BPF cookie. This eliminates the need to determine a USDT call site (and
thus specifics about how exactly to fetch arguments) based on its *absolute IP
address*, which is impossible with shared libraries if no PID is specified (as
we then just *can't* know absolute IP at which shared library is loaded,
because it might be different for each process). With BPF cookie this is not
a problem as we record "call site ID" directly in a BPF cookie value. This
makes it possible to do a system-wide tracing of a USDT defined in a shared
library. Think about tracing some USDT in libc across any process in the
system, both running at the time of attachment and all the new processes
started *afterwards*. This is a very powerful capability that allows more
efficient observability and tracing tooling.
Once this functionality lands, the plan is to extend libbpf-bootstrap ([0])
with an USDT example. It will also become possible to start converting BCC
tools that rely on USDTs to their libbpf-based counterparts ([1]).
It's worth noting that preliminary version of this code was currently used and
tested in production code running fleet-wide observability toolkit.
Libbpf functionality is broken down into 5 mostly logically independent parts,
for ease of reviewing:
- patch #1 adds BPF-side implementation;
- patch #2 adds user-space APIs and wires bpf_link for USDTs;
- patch #3 adds the most mundate pieces: handling ELF, parsing USDT notes,
dealing with memory segments, relative vs absolute addresses, etc;
- patch #4 adds internal ID allocation and setting up/tearing down of
BPF-side state (spec and IP-to-ID mapping);
- patch #5 implements x86/x86-64-specific logic of parsing USDT argument
specifications;
- patch #6 adds testing of various basic aspects of handling of USDT;
- patch #7 extends the set of tests with more combinations of semaphore,
executable vs shared library, and PID filter options.
[0] https://github.com/libbpf/libbpf-bootstrap
[1] https://github.com/iovisor/bcc/tree/master/libbpf-tools
v2->v3:
- fix typos, leave link to systemtap doc, acks, etc (Dave);
- include sys/sdt.h to avoid extra system-wide package dependencies;
v1->v2:
- huge high-level comment describing how all the moving parts fit together
(Alan, Alexei);
- switched from `__hidden __weak` to `static inline __noinline` for now, as
there is a bug in BPF linker breaking final BPF object file due to invalid
.BTF.ext data; I want to fix it separately at which point I'll switch back
to __hidden __weak again. The fix isn't trivial, so I don't want to block
on that. Same for __weak variable lookup bug that Henqi reported.
- various fixes and improvements, addressing other feedback (Alan, Hengqi);
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Dave Marchevsky <davemarchevsky@fb.com>
Cc: Hengqi Chen <hengqi.chen@gmail.com>
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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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
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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
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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
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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
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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
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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
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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
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Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Incorrect comparison in bitmask .reduce, from Jeremy Sowden.
2) Missing GFP_KERNEL_ACCOUNT for dynamically allocated objects,
from Vasily Averin.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_tables: memcg accounting for dynamically allocated objects
netfilter: bitwise: fix reduce comparisons
====================
Link: https://lore.kernel.org/r/20220405100923.7231-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Pull virtio fixes from Michael Tsirkin:
"Fixes and cleanups:
- A couple of mlx5 fixes related to cvq
- A couple of reverts dropping useless code (code that used it got
reverted earlier)"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vdpa: mlx5: synchronize driver status with CVQ
vdpa: mlx5: prevent cvq work from hogging CPU
Revert "virtio_config: introduce a new .enable_cbs method"
Revert "virtio: use virtio_device_ready() in virtio_device_restore()"
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After resuming from suspend-to-RAM, the MSRs that control CPU's
speculative execution behavior are not being restored on the boot CPU.
These MSRs are used to mitigate speculative execution vulnerabilities.
Not restoring them correctly may leave the CPU vulnerable. Secondary
CPU's MSRs are correctly being restored at S3 resume by
identify_secondary_cpu().
During S3 resume, restore these MSRs for boot CPU when restoring its
processor state.
Fixes: 772439717dbf ("x86/bugs/intel: Set proper CPU features and setup RDS")
Reported-by: Neelima Krishnan <neelima.krishnan@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The mechanism to save/restore MSRs during S3 suspend/resume checks for
the MSR validity during suspend, and only restores the MSR if its a
valid MSR. This is not optimal, as an invalid MSR will unnecessarily
throw an exception for every suspend cycle. The more invalid MSRs,
higher the impact will be.
Check and save the MSR validity at setup. This ensures that only valid
MSRs that are guaranteed to not throw an exception will be attempted
during suspend.
Fixes: 7a9c2dd08ead ("x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume")
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently when XDP rings are created, each descriptor gets its DD bit
set, which turns out to be the wrong approach as it can lead to a
situation where more descriptors get cleaned than it was supposed to,
e.g. when AF_XDP busy poll is run with a large batch size. In this
situation, the driver would request for more buffers than it is able to
handle.
Fix this by not setting the DD bits in ice_xdp_alloc_setup_rings(). They
should be initialized to zero instead.
Fixes: 9610bd988df9 ("ice: optimize XDP_TX workloads")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Shwetha Nagaraju <shwetha.nagaraju@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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ICE_DOWN is dedicated for pf->state. Check for ICE_VSI_DOWN being set on
vsi->state in ice_xsk_wakeup().
Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Shwetha Nagaraju <shwetha.nagaraju@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Unfortunately, the ice driver doesn't respect the RCU critical section that
XSK wakeup is surrounded with. To fix this, add synchronize_rcu() calls to
paths that destroy resources that might be in use.
This was addressed in other AF_XDP ZC enabled drivers, for reference see
for example commit b3873a5be757 ("net/i40e: Fix concurrency issues
between config flow and XSK")
Fixes: efc2214b6047 ("ice: Add support for XDP")
Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Shwetha Nagaraju <shwetha.nagaraju@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- prevent deleting subvolume with active swapfile
- fix qgroup reserve limit calculation overflow
- remove device count in superblock and its item in one transaction so
they cant't get out of sync
- skip defragmenting an isolated sector, this could cause some extra IO
- unify handling of mtime/permissions in hole punch with fallocate
- zoned mode fixes:
- remove assert checking for only single mode, we have the
DUP mode implemented
- fix potential lockdep warning while traversing devices
when checking for zone activation
* tag 'for-5.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: prevent subvol with swapfile from being deleted
btrfs: do not warn for free space inode in cow_file_range
btrfs: avoid defragging extents whose next extents are not targets
btrfs: fix fallocate to use file_modified to update permissions consistently
btrfs: remove device item and update super block in the same transaction
btrfs: fix qgroup reserve overflow the qgroup limit
btrfs: zoned: remove left over ASSERT checking for single profile
btrfs: zoned: traverse devices under chunk_mutex in btrfs_can_activate_zone
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In 6f98a4bfee72 ("random: block in /dev/urandom"), we tried to make a
successful try_to_generate_entropy() call *required* if the RNG was not
already initialized. Unfortunately, weird architectures and old
userspaces combined in TCG test harnesses, making that change still not
realistic, so it was reverted in 0313bc278dac ("Revert "random: block in
/dev/urandom"").
However, rather than making a successful try_to_generate_entropy() call
*required*, we can instead make it *best-effort*.
If try_to_generate_entropy() fails, it fails, and nothing changes from
the current behavior. If it succeeds, then /dev/urandom becomes safe to
use for free. This way, we don't risk the regression potential that led
to us reverting the required-try_to_generate_entropy() call before.
Practically speaking, this means that at least on x86, /dev/urandom
becomes safe. Probably other architectures with working cycle counters
will also become safe. And architectures with slow or broken cycle
counters at least won't be affected at all by this change.
So it may not be the glorious "all things are unified!" change we were
hoping for initially, but practically speaking, it makes a positive
impact.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
|
VRF devices are the loopbacks for VRFs, and a loopback can not be
assigned to a VRF. Accordingly, the condition in ip6_pkt_drop should
be '||' not '&&'.
Fixes: 1d3fd8a10bed ("vrf: Use orig netdev to count Ip6InNoRoutes and a fresh route lookup when sending dest unreach")
Reported-by: Pudak, Filip <Filip.Pudak@windriver.com>
Reported-by: Xiao, Jiguang <Jiguang.Xiao@windriver.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220404150908.2937-1-dsahern@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Tony Nguyen says:
====================
ice bug fixes
Alice Michael says:
There were a couple of bugs that have been found and
fixed by Anatolii in the ice driver. First he fixed
a bug on ring creation by setting the default value
for the teid. Anatolli also fixed a bug with deleting
queues in ice_vc_dis_qs_msg based on their enablement.
---
v2: Remove empty lines between tags
The following are changes since commit 458f5d92df4807e2a7c803ed928369129996bf96:
sfc: Do not free an empty page_ring
and are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue 100GbE
====================
Link: https://lore.kernel.org/r/20220404183548.3422851-1-anthony.l.nguyen@intel.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Disable check for queue being enabled in ice_vc_dis_qs_msg, because
there could be a case when queues were created, but were not enabled.
We still need to delete those queues.
Normal workflow for VF looks like:
Enable path:
VIRTCHNL_OP_ADD_ETH_ADDR (opcode 10)
VIRTCHNL_OP_CONFIG_VSI_QUEUES (opcode 6)
VIRTCHNL_OP_ENABLE_QUEUES (opcode 8)
Disable path:
VIRTCHNL_OP_DISABLE_QUEUES (opcode 9)
VIRTCHNL_OP_DEL_ETH_ADDR (opcode 11)
The issue appears only in stress conditions when VF is enabled and
disabled very fast.
Eventually there will be a case, when queues are created by
VIRTCHNL_OP_CONFIG_VSI_QUEUES, but are not enabled by
VIRTCHNL_OP_ENABLE_QUEUES.
In turn, these queues are not deleted by VIRTCHNL_OP_DISABLE_QUEUES,
because there is a check whether queues are enabled in
ice_vc_dis_qs_msg.
When we bring up the VF again, we will see the "Failed to set LAN Tx queue
context" error during VIRTCHNL_OP_CONFIG_VSI_QUEUES step. This
happens because old 16 queues were not deleted and VF requests to create
16 more, but ice_sched_get_free_qparent in ice_ena_vsi_txq would fail to
find a parent node for first newly requested queue (because all nodes
are allocated to 16 old queues).
Testing Hints:
Just enable and disable VF fast enough, so it would be disabled before
reaching VIRTCHNL_OP_ENABLE_QUEUES.
while true; do
ip link set dev ens785f0v0 up
sleep 0.065 # adjust delay value for you machine
ip link set dev ens785f0v0 down
done
Fixes: 77ca27c41705 ("ice: add support for virtchnl_queue_select.[tx|rx]_queues bitmap")
Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Alice Michael <alice.michael@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
When VF is freshly created, but not brought up, ring->txq_teid
value is by default set to 0.
But 0 is a valid TEID. On some platforms the Root Node of
Tx scheduler has a TEID = 0. This can cause issues as shown below.
The proper way is to set ring->txq_teid to ICE_INVAL_TEID (0xFFFFFFFF).
Testing Hints:
echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
ip link set dev ens785f0v0 up
ip link set dev ens785f0v0 down
If we have freshly created VF and quickly turn it on and off, so there
would be no time to reach VIRTCHNL_OP_CONFIG_VSI_QUEUES stage, then
VIRTCHNL_OP_DISABLE_QUEUES stage will fail with error:
[ 639.531454] disable queue 89 failed 14
[ 639.532233] Failed to disable LAN Tx queues, error: ICE_ERR_AQ_ERROR
[ 639.533107] ice 0000:02:00.0: Failed to stop Tx ring 0 on VSI 5
The reason for the fail is that we are trying to send AQ command to
delete queue 89, which has never been created and receive an "invalid
argument" error from firmware.
As this queue has never been created, it's teid and ring->txq_teid
have default value 0.
ice_dis_vsi_txq has a check against non-existent queues:
node = ice_sched_find_node_by_teid(pi->root, q_teids[i]);
if (!node)
continue;
But on some platforms the Root Node of Tx scheduler has a teid = 0.
Hence, ice_sched_find_node_by_teid finds a node with teid = 0 (it is
pi->root), and we go further to submit an erroneous request to firmware.
Fixes: 37bb83901286 ("ice: Move common functions out of ice_main.c part 7/7")
Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Alice Michael <alice.michael@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
This node pointer is returned by of_find_compatible_node() with
refcount incremented. Calling of_node_put() to aovid the refcount leak.
Fixes: d346c9e86d86 ("dpaa2-ptp: reuse ptp_qoriq driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220404125336.13427-1-linmq006@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
nft_*.c files whose NFT_EXPR_STATEFUL flag is set on need to
use __GFP_ACCOUNT flag for objects that are dynamically
allocated from the packet path.
Such objects are allocated inside nft_expr_ops->init() callbacks
executed in task context while processing netlink messages.
In addition, this patch adds accounting to nft_set_elem_expr_clone()
used for the same purposes.
Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
|
|
Singleton chunks (INIT, HEARTBEAT PMTU probes, and SHUTDOWN-
COMPLETE) are not counted in SCTP_GET_ASOC_STATS "sas_octrlchunks"
counter available to the assoc owner.
These are all control chunks so they should be counted as such.
Add counting of singleton chunks so they are properly accounted for.
Fixes: 196d67593439 ("sctp: Add support to per-association statistics via a new SCTP_GET_ASSOC_STATS call")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://lore.kernel.org/r/c9ba8785789880cf07923b8a5051e174442ea9ee.1649029663.git.jamie.bainbridge@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
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
|
|
attach_probe selftest fails on aarch64 with `failed to create kprobe
'sys_nanosleep+0x0' perf event: No such file or directory`. This is
because, like on several other architectures, nanosleep has a prefix.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220404142101.27900-1-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>
|
|
Previously [1], we were using bpf_probe_prog_type which returned a
bool, but the new libbpf_probe_bpf_prog_type can return a negative
error code on failure. This change decides for bpftool to declare
a program type is not available on probe failure.
[1] https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@kernel.org/
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220331154555.422506-4-milan@mdaverde.com
|
|
Will display the link type names in bpftool link show output
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220331154555.422506-3-milan@mdaverde.com
|
|
In addition to displaying the program type in bpftool prog show
this enables us to be able to query bpf_prog_type_syscall
availability through feature probe as well as see
which helpers are available in those programs (such as
bpf_sys_bpf and bpf_sys_close)
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220331154555.422506-2-milan@mdaverde.com
|
|
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: 85bf1f51691c ("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
|
|
At the end of the test, we already print out
prog <prog number>: map ids <...> <...>
Value is the number read from kernel through bpf map, further print out
verify map:<map id> val:<...>
will help users to understand the program runs successfully.
Signed-off-by: Song Chen <chensong_2000@189.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648889828-12417-1-git-send-email-chensong_2000@189.cn
|
|
add_hwgenerator_randomness() tries to only use the required amount of input
for fast init, but credits all the entropy, rather than a fraction of
it. Since it's hard to determine how much entropy is left over out of a
non-unformly random sample, either give it all to fast init or credit
it, but don't attempt to do both. In the process, we can clean up the
injection code to no longer need to return a value.
Signed-off-by: Jan Varho <jan.varho@gmail.com>
[Jason: expanded commit message]
Fixes: 73c7733f122e ("random: do not throw away excess input to crng_fast_load")
Cc: stable@vger.kernel.org # 5.17+, requires af704c856e88
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
|
When the page_ring is not used page_ptr_mask is 0.
Do not dereference page_ring[0] in this case.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Smatch reports this issue
dwmac-loongson.c:208:19: warning: symbol
'loongson_dwmac_driver' was not declared.
Should it be static?
loongson_dwmac_driver is only used in dwmac-loongson.c.
File scope variables used only in one file should
be static. Change loongson_dwmac_driver's
storage-class-specifier from global to static.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Michael Chan says:
====================
bnxt_en: XDP redirect fixes
This series includes 3 fixes related to the XDP redirect code path in
the driver. The first one adds locking when the number of TX XDP rings
is less than the number of CPUs. The second one adjusts the maximum MTU
that can support XDP with enough tail room in the buffer. The 3rd one
fixes a race condition between TX ring shutdown and the XDP redirect path.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Add checks in the XDP redirect callback to prevent XDP from running when
the TX ring is undergoing shutdown.
Also remove redundant checks in the XDP redirect callback to validate the
txr and the flag that indicates the ring supports XDP. The modulo
arithmetic on 'tx_nr_rings_xdp' already guarantees the derived TX
ring is an XDP ring. txr is also guaranteed to be valid after checking
BNXT_STATE_OPEN and within RCU grace period.
Fixes: f18c2b77b2e4 ("bnxt_en: optimized XDP_REDIRECT support")
Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Insufficient space was being reserved in the page used for packet
reception, so the interface MTU could be set too large to still have
room for the contents of the packet when doing XDP redirect. This
resulted in the following message when redirecting a packet between
3520 and 3822 bytes with an MTU of 3822:
[311815.561880] XDP_WARN: xdp_update_frame_from_buff(line:200): Driver BUG: missing reserved tailroom
Fixes: f18c2b77b2e4 ("bnxt_en: optimized XDP_REDIRECT support")
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
If there are more CPUs than the number of TX XDP rings, multiple XDP
redirects can select the same TX ring based on the CPU on which
XDP redirect is called. Add locking when needed and use static
key to decide whether to take the lock.
Fixes: f18c2b77b2e4 ("bnxt_en: optimized XDP_REDIRECT support")
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
To fix a coverity complain, commit d5ac07dfbd2b
("qed: Initialize debug string array") removed "sw-platform"
(one of the common global parameters) from the dump as this
was used in the dump with an uninitialized string, however
it did not reduce the number of common global parameters
which caused the incorrect (unable to parse) register dump
this patch fixes it with reducing NUM_COMMON_GLOBAL_PARAMS
bye one.
Cc: stable@vger.kernel.org
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Fixes: d5ac07dfbd2b ("qed: Initialize debug string array")
Signed-off-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: Alok Prasad <palok@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Manish Chopra <manishc@marvell.com>
Reviewed-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Horatiu Vultur says:
====================
net: phy: micrel: Remove latencies support lan8814
Remove the latencies support both from the PHY driver and from the DT.
The IP already has some default latencies values which can be used to get
decent results. It has the following values(defined in ns):
rx-1000mbit: 429
tx-1000mbit: 201
rx-100mbit: 2346
tx-100mbit: 705
v0->v1:
- fix the split of the patches, there was a compiling error between patch 2 and
patch 3.
---
But to get better results the following values needs to be set:
rx-1000mbit: 459
tx-1000mbit: 171
rx-100mbit: 1706
tx-100mbit: 1345
We are proposing to use ethtool to set these latencies, the RFC can be found
here[1]
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
When the PHY and the MAC are capable of doing timestamping, the PHY has
priority. Therefore the DT option lan8814,ignore-ts was added such that
the PHY will not expose a PHC so then the timestamping was done in the
MAC. This is not the correct approach of doing it, therefore remove
this.
Fixes: ece19502834d84 ("net: phy: micrel: 1588 support for LAN8814 phy")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Based on the discussions here[1], the PHY driver is the wrong place
to set the latencies, therefore remove them.
[1] https://lkml.org/lkml/2022/3/4/325
Fixes: ece19502834d84 ("net: phy: micrel: 1588 support for LAN8814 phy")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Revert latency support from binding.
Based on the discussion[1], the DT is the wrong place to have the
lantecies for the PHY.
[1] https://lkml.org/lkml/2022/3/4/325
Fixes: 2358dd3fd325fc ("dt-bindings: net: micrel: Configure latency values and timestamping check for LAN8814 phy")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Since core relos is an optional part of the .BTF.ext ELF section, we should
skip parsing it instead of returning -EINVAL if header size is less than
offsetofend(struct btf_ext_header, core_relo_len).
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220404005320.1723055-1-ytcoode@gmail.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>
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tests that verify auto-attach works for function entry/return for
local functions in program and library functions in a library.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1648654000-21758-6-git-send-email-alan.maguire@oracle.com
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