- 01 Jun, 2019 1 commit
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Jiong Wang authored
There has been quite a few progress around the two steps mentioned in the answer to the following question: Q: BPF 32-bit subregister requirements This patch updates the answer to reflect what has been done. v2: - Add missing full stop. (Song Liu) - Minor tweak on one sentence. (Song Liu) v1: - Integrated rephrase from Quentin and Jakub Reviewed-by:
Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by:
Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:
Jiong Wang <jiong.wang@netronome.com> Acked-by:
Song Liu <songliubraving@fb.com> Signed-off-by:
Alexei Starovoitov <ast@kernel.org>
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- 31 May, 2019 13 commits
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Alexei Starovoitov authored
Roman Gushchin says: ==================== During my work on memcg-based memory accounting for bpf maps I've done some cleanups and refactorings of the existing memlock rlimit-based code. It makes it more robust, unifies size to pages conversion, size checks and corresponding error codes. Also it adds coverage for cgroup local storage and socket local storage maps. It looks like some preliminary work on the mm side might be required to start working on the memcg-based accounting, so I'm sending these patches as a separate patchset. ==================== Signed-off-by: -
Roman Gushchin authored
Most bpf map types doing similar checks and bytes to pages conversion during memory allocation and charging. Let's unify these checks by moving them into bpf_map_charge_init(). Signed-off-by:
Roman Gushchin <guro@fb.com> Acked-by:
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Roman Gushchin authored
In order to unify the existing memlock charging code with the memcg-based memory accounting, which will be added later, let's rework the current scheme. Currently the following design is used: 1) .alloc() callback optionally checks if the allocation will likely succeed using bpf_map_precharge_memlock() 2) .alloc() performs actual allocations 3) .alloc() callback calculates map cost and sets map.memory.pages 4) map_create() calls bpf_map_init_memlock() which sets map.memory.user and performs actual charging; in case of failure the map is destroyed <map is in use> 1) bpf_map_free_deferred() calls bpf_map_release_memlock(), which performs uncharge and releases the user 2) .map_free() callback releases the memory The scheme can be simplified and made more robust: 1) .alloc() calculates map cost and calls bpf_map_charge_init() 2) bpf_map_charge_init() sets map.memory.user and performs actual charge 3) .alloc() performs actual allocations <map is in use> 1) .map_free() callback releases the memory 2) bpf_map_charge_finish() performs uncharge and releases the user The new scheme also allows to reuse bpf_map_charge_init()/finish() functions for memcg-based accounting. Because charges are performed before actual allocations and uncharges after freeing the memory, no bogus memory pressure can be created. In cases when the map structure is not available (e.g. it's not created yet, or is already destroyed), on-stack bpf_map_memory structure is used. The charge can be transferred with the bpf_map_charge_move() function. Signed-off-by: -
Roman Gushchin authored
Group "user" and "pages" fields of bpf_map into the bpf_map_memory structure. Later it can be extended with "memcg" and other related information. The main reason for a such change (beside cosmetics) is to pass bpf_map_memory structure to charging functions before the actual allocation of bpf_map. Signed-off-by:
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Roman Gushchin authored
Socket local storage maps lack the memlock precharge check, which is performed before the memory allocation for most other bpf map types. Let's add it in order to unify all map types. Signed-off-by:
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Roman Gushchin authored
Cgroup local storage maps lack the memlock precharge check, which is performed before the memory allocation for most other bpf map types. Let's add it in order to unify all map types. Signed-off-by:
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Alexei Starovoitov authored
Lawrence Brakmo says: ==================== This patchset adds support for propagating congestion notifications (cn) to TCP from cgroup inet skb egress BPF programs. Current cgroup skb BPF programs cannot trigger TCP congestion window reductions, even when they drop a packet. This patch-set adds support for cgroup skb BPF programs to send congestion notifications in the return value when the packets are TCP packets. Rather than the current 1 for keeping the packet and 0 for dropping it, they can now return: NET_XMIT_SUCCESS (0) - continue with packet output NET_XMIT_DROP (1) - drop packet and do cn NET_XMIT_CN (2) - continue with packet output and do cn -EPERM - drop packet Finally, HBM programs are modified to collect and return more statistics. There has been some discussion regarding the best place to manage bandwidths. Some believe this should be done in the qdisc where it can also be managed with a BPF program. We believe there are advantages for doing it with a BPF program in the cgroup/skb callback. For example, it reduces overheads in the cases where there is on primary workload and one or more secondary workloads, where each workload is running on its own cgroupv2. In this scenario, we only need to throttle the secondary workloads and there is no overhead for the primary workload since there will be no BPF program attached to its cgroup. Regardless, we agree that this mechanism should not penalize those that are not using it. We tested this by doing 1 byte req/reply RPCs over loopback. Each test consists of 30 sec of back-to-back 1 byte RPCs. Each test was repeated 50 times with a 1 minute delay between each set of 10. We then calculated the average RPCs/sec over the 50 tests. We compare upstream with upstream + patchset and no BPF program as well as upstream + patchset and a BPF program that just returns ALLOW_PKT. Here are the results: upstream 80937 RPCs/sec upstream + patches, no BPF program 80894 RPCs/sec upstream + patches, BPF program 80634 RPCs/sec These numbers indicate that there is no penalty for these patches The use of congestion notifications improves the performance of HBM when using Cubic. Without congestion notifications, Cubic will not decrease its cwnd and HBM will need to drop a large percentage of the packets. The following results are obtained for rate limits of 1Gbps, between two servers using netperf, and only one flow. We also show how reducing the max delayed ACK timer can improve the performance when using Cubic. Command used was: ./do_hbm_test.sh -l -D --stats -N -r=<rate> [--no_cn] [dctcp] \ -s=<server running netserver> where: <rate> is 1000 --no_cn specifies no cwr notifications dctcp uses dctcp Cubic DCTCP Lim, DA Mbps cwnd cred drops Mbps cwnd cred drops -------- ---- ---- ---- ----- ---- ---- ---- ----- 1G, 40 35 462 -320 67% 995 1 -212 0.05% 1G, 40,cn 736 9 -78 0.07 995 1 -212 0.05 1G, 5,cn 941 2 -189 0.13 995 1 -212 0.05 Notes: --no_cn has no effect with DCTCP Lim = rate limit DA = maximum delay ack timer cred = credit in packets drops = % packets dropped v1->v2: Insures that only BPF_CGROUP_INET_EGRESS can return values 2 and 3 New egress values apply to all protocols, not just TCP Cleaned up patch 4, Update BPF_CGROUP_RUN_PROG_INET_EGRESS callers Removed changes to __tcp_transmit_skb (patch 5), no longer needed Removed sample use of EDT v2->v3: Removed the probe timer related changes v3->v4: Replaced preempt_enable_no_resched() by preempt_enable() in BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY() macro ==================== Acked-by:Martin KaFai Lau <kafai@fb.com> Signed-off-by:
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brakmo authored
Adds more stats to HBM, including average cwnd and rtt of all TCP flows, percents of packets that are ecn ce marked and distribution of return values. Signed-off-by:
Lawrence Brakmo <brakmo@fb.com> Signed-off-by:
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brakmo authored
Update hbm_out_kern.c to support returning cn notifications. Also updates relevant files to allow disabling cn notifications. Signed-off-by:
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brakmo authored
Update BPF_CGROUP_RUN_PROG_INET_EGRESS() callers to support returning congestion notifications from the BPF programs. Signed-off-by:
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brakmo authored
For egress packets, __cgroup_bpf_fun_filter_skb() will now call BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY() instead of PROG_CGROUP_RUN_ARRAY() in order to propagate congestion notifications (cn) requests to TCP callers. For egress packets, this function can return: NET_XMIT_SUCCESS (0) - continue with packet output NET_XMIT_DROP (1) - drop packet and notify TCP to call cwr NET_XMIT_CN (2) - continue with packet output and notify TCP to call cwr -EPERM - drop packet For ingress packets, this function will return -EPERM if any attached program was found and if it returned != 1 during execution. Otherwise 0 is returned. Signed-off-by: -
brakmo authored
Allows cgroup inet skb programs to return values in the range [0, 3]. The second bit is used to deterine if congestion occurred and higher level protocol should decrease rate. E.g. TCP would call tcp_enter_cwr() The bpf_prog must set expected_attach_type to BPF_CGROUP_INET_EGRESS at load time if it uses the new return values (i.e. 2 or 3). The expected_attach_type is currently not enforced for BPF_PROG_TYPE_CGROUP_SKB. e.g Meaning the current bpf_prog with expected_attach_type setting to BPF_CGROUP_INET_EGRESS can attach to BPF_CGROUP_INET_INGRESS. Blindly enforcing expected_attach_type will break backward compatibility. This patch adds a enforce_expected_attach_type bit to only enforce the expected_attach_type when it uses the new return value. Signed-off-by:
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brakmo authored
Create new macro BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY() to be used by __cgroup_bpf_run_filter_skb for EGRESS BPF progs so BPF programs can request cwr for TCP packets. Current cgroup skb programs can only return 0 or 1 (0 to drop the packet. This macro changes the behavior so the low order bit indicates whether the packet should be dropped (0) or not (1) and the next bit is used for congestion notification (cn). Hence, new allowed return values of CGROUP EGRESS BPF programs are: 0: drop packet 1: keep packet 2: drop packet and call cwr 3: keep packet and call cwr This macro then converts it to one of NET_XMIT values or -EPERM that has the effect of dropping the packet with no cn. 0: NET_XMIT_SUCCESS skb should be transmitted (no cn) 1: NET_XMIT_DROP skb should be dropped and cwr called 2: NET_XMIT_CN skb should be transmitted and cwr called 3: -EPERM skb should be dropped (no cn) Note that when more than one BPF program is called, the packet is dropped if at least one of programs requests it be dropped, and there is cn if at least one program returns cn. Signed-off-by:
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- 29 May, 2019 15 commits
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Andrii Nakryiko authored
There are a bunch of lines of code or comments that are unnecessary wrapped into multi-lines. Fix that without violating any code guidelines. Acked-by:
Andrii Nakryiko <andriin@fb.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net>
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Andrii Nakryiko authored
A bunch of typo and formatting fixes. Acked-by:
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Andrii Nakryiko authored
Extra check for type is unnecessary in first case. Extra zeroing is unnecessary, as snprintf guarantees that it will zero-terminate string. Acked-by:
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Andrii Nakryiko authored
0 is a valid FD, so it's better to initialize it to -1, as is done in other places. Also, technically, BTF type ID 0 is valid (it's a VOID type), so it's more reliable to check btf_fd, instead of btf_key_type_id, to determine if there is any BTF associated with a map. Acked-by:
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Andrii Nakryiko authored
All of libbpf errors are negative, except this one. Fix it. Acked-by:
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Andrii Nakryiko authored
Validate there was no error retrieving symbol name corresponding to a BPF map. Acked-by:
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Andrii Nakryiko authored
Rewrite endianness check to use "more canonical" way, using compiler-defined macros, similar to few other places in libbpf. It also is more obvious and shorter. Acked-by:
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Andrii Nakryiko authored
pr_warning ultimately may call into user-provided callback function, which can clobber errno value, so we need to save it before that. Acked-by:
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Andrii Nakryiko authored
Ensure that size of a section w/ BPF instruction is exactly a multiple of BPF instruction size. Signed-off-by:
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Quentin Monnet authored
There are two functions in libbpf that support passing a log_level parameter for the verifier for loading programs: bpf_object__load_xattr() and bpf_prog_load_xattr(). Both accept an attribute object containing the log_level, and apply it to the programs to load. It turns out that to effectively load the programs, the latter function eventually relies on the former. This was not taken into account when adding support for log_level in bpf_object__load_xattr(), and the log_level passed to bpf_prog_load_xattr() later gets overwritten with a zero value, thus disabling verifier logs for the program in all cases: bpf_prog_load_xattr() // prog->log_level = attr1->log_level; -> bpf_object__load() // attr2->log_level = 0; -> bpf_object__load_xattr() // <pass prog and attr2> -> bpf_object__load_progs() // prog->log_level = attr2->log_level; Fix this by OR-ing the log_level in bpf_object__load_progs(), instead of overwriting it. v2: Fix commit log description (confusion on function names in v1). Fixes: 60276f98 ("libbpf: add bpf_object__load_xattr() API function to pass log_level") Reported-by: -
Stanislav Fomichev authored
Now that we don't have __rcu markers on the bpf_prog_array helpers, let's use proper rcu_dereference_protected to obtain array pointer under mutex. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by:
Stanislav Fomichev <sdf@google.com> Signed-off-by:
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Stanislav Fomichev authored
Now that we don't have __rcu markers on the bpf_prog_array helpers, let's use proper rcu_dereference_protected to obtain array pointer under mutex. We also don't need __rcu annotations on cgroup_bpf.inactive since it's not read/updated concurrently. v4: * drop cgroup_rcu_xyz wrappers and use rcu APIs directly; presumably should be more clear to understand which mutex/refcount protects each particular place v3: * amend cgroup_rcu_dereference to include percpu_ref_is_dying; cgroup_bpf is now reference counted and we don't hold cgroup_mutex anymore in cgroup_bpf_release v2: * replace xchg with rcu_swap_protected Cc: Roman Gushchin <guro@fb.com> Signed-off-by:
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Stanislav Fomichev authored
Now that we don't have __rcu markers on the bpf_prog_array helpers, let's use proper rcu_dereference_protected to obtain array pointer under mutex. Cc: linux-media@vger.kernel.org Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Sean Young <sean@mess.org> Signed-off-by:
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Stanislav Fomichev authored
Drop __rcu annotations and rcu read sections from bpf_prog_array helper functions. They are not needed since all existing callers call those helpers from the rcu update side while holding a mutex. This guarantees that use-after-free could not happen. In the next patches I'll fix the callers with missing rcu_dereference_protected to make sparse/lockdep happy, the proper way to use these helpers is: struct bpf_prog_array __rcu *progs = ...; struct bpf_prog_array *p; mutex_lock(&mtx); p = rcu_dereference_protected(progs, lockdep_is_held(&mtx)); bpf_prog_array_length(p); bpf_prog_array_copy_to_user(p, ...); bpf_prog_array_delete_safe(p, ...); bpf_prog_array_copy_info(p, ...); bpf_prog_array_copy(p, ...); bpf_prog_array_free(p); mutex_unlock(&mtx); No functional changes! rcu_dereference_protected with lockdep_is_held should catch any cases where we update prog array without a mutex (I've looked at existing call sites and I think we hold a mutex everywhere). Motivation is to fix sparse warnings: kernel/bpf/core.c:1803:9: warning: incorrect type in argument 1 (different address spaces) kernel/bpf/core.c:1803:9: expected struct callback_head *head kernel/bpf/core.c:1803:9: got struct callback_head [noderef] <asn:4> * kernel/bpf/core.c:1877:44: warning: incorrect type in initializer (different address spaces) kernel/bpf/core.c:1877:44: expected struct bpf_prog_array_item *item kernel/bpf/core.c:1877:44: got struct bpf_prog_array_item [noderef] <asn:4> * kernel/bpf/core.c:1901:26: warning: incorrect type in assignment (different address spaces) kernel/bpf/core.c:1901:26: expected struct bpf_prog_array_item *existing kernel/bpf/core.c:1901:26: got struct bpf_prog_array_item [noderef] <asn:4> * kernel/bpf/core.c:1935:26: warning: incorrect type in assignment (different address spaces) kernel/bpf/core.c:1935:26: expected struct bpf_prog_array_item *[assigned] existing kernel/bpf/core.c:1935:26: got struct bpf_prog_array_item [noderef] <asn:4> * v2: * remove comment about potential race; that can't happen because all callers are in rcu-update section Cc: Roman Gushchin <guro@fb.com> Acked-by:
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Alan Maguire authored
When building the tools/testing/selftest/bpf subdirectory, (running both a local directory "make" and a "make -C tools/testing/selftests/bpf") I keep hitting the following compilation error: prog_tests/flow_dissector.c: In function ‘create_tap’: prog_tests/flow_dissector.c:150:38: error: ‘IFF_NAPI’ undeclared (first use in this function) .ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS, ^ prog_tests/flow_dissector.c:150:38: note: each undeclared identifier is reported only once for each function it appears in prog_tests/flow_dissector.c:150:49: error: ‘IFF_NAPI_FRAGS’ undeclared Adding include/uapi/linux/if_tun.h to tools/include/uapi/linux resolves the problem and ensures the compilation of the file does not depend on having up-to-date kernel headers locally. Signed-off-by:Alan Maguire <alan.maguire@oracle.com> Signed-off-by:
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- 28 May, 2019 11 commits
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Alexei Starovoitov authored
Roman Gushchin says: ==================== This patchset implements a cgroup bpf auto-detachment functionality: bpf programs are detached as soon as possible after removal of the cgroup, without waiting for the release of all associated resources. Patches 2 and 3 are required to implement a corresponding kselftest in patch 4. v5: 1) rebase v4: 1) release cgroup bpf data using a workqueue 2) add test_cgroup_attach to .gitignore v3: 1) some minor changes and typo fixes v2: 1) removed a bogus check in patch 4 2) moved buf[len] = 0 in patch 2 ==================== Signed-off-by: -
Roman Gushchin authored
Add a kselftest to cover bpf auto-detachment functionality. The test creates a cgroup, associates some resources with it, attaches a couple of bpf programs and deletes the cgroup. Then it checks that bpf programs are going away in 5 seconds. Expected output: $ ./test_cgroup_attach #override:PASS #multi:PASS #autodetach:PASS test_cgroup_attach:PASS On a kernel without auto-detaching: $ ./test_cgroup_attach #override:PASS #multi:PASS #autodetach:FAIL test_cgroup_attach:FAIL Signed-off-by:
Yonghong Song <yhs@fb.com> Signed-off-by:
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Roman Gushchin authored
Enable all available cgroup v2 controllers when setting up the environment for the bpf kselftests. It's required to properly test the bpf prog auto-detach feature. Also it will generally increase the code coverage. Signed-off-by:
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Roman Gushchin authored
Convert test_cgrp2_attach2 example into a proper test_cgroup_attach kselftest. It's better because we do run kselftest on a constant basis, so there are better chances to spot a potential regression. Also make it slightly less verbose to conform kselftests output style. Output example: $ ./test_cgroup_attach #override:PASS #multi:PASS test_cgroup_attach:PASS Signed-off-by:
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Roman Gushchin authored
Currently the lifetime of bpf programs attached to a cgroup is bound to the lifetime of the cgroup itself. It means that if a user forgets (or intentionally avoids) to detach a bpf program before removing the cgroup, it will stay attached up to the release of the cgroup. Since the cgroup can stay in the dying state (the state between being rmdir()'ed and being released) for a very long time, it leads to a waste of memory. Also, it blocks a possibility to implement the memcg-based memory accounting for bpf objects, because a circular reference dependency will occur. Charged memory pages are pinning the corresponding memory cgroup, and if the memory cgroup is pinning the attached bpf program, nothing will be ever released. A dying cgroup can not contain any processes, so the only chance for an attached bpf program to be executed is a live socket associated with the cgroup. So in order to release all bpf data early, let's count associated sockets using a new percpu refcounter. On cgroup removal the counter is transitioned to the atomic mode, and as soon as it reaches 0, all bpf programs are detached. Because cgroup_bpf_release() can block, it can't be called from the percpu ref counter callback directly, so instead an asynchronous work is scheduled. The reference counter is not socket specific, and can be used for any other types of programs, which can be executed from a cgroup-bpf hook outside of the process context, had such a need arise in the future. Signed-off-by:
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Daniel T. Lee authored
This commit fixes a few style problems in samples/bpf/bpf_load.c: - Magic string use of 'DEBUGFS' - Useless zero initialization of a global variable - Minor style fix with whitespace Signed-off-by:
Daniel T. Lee <danieltimlee@gmail.com> Acked-by:
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Stanislav Fomichev authored
Right now test_tunnel.sh always exits with success even if some of the subtests fail. Since the output is very verbose, it's hard to spot the issues with subtests. Let's fail the script if any subtest fails. Signed-off-by:
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Daniel Borkmann authored
Quentin Monnet says: ==================== This series adds an option to bpftool to make it print additional information via libbpf and the kernel verifier when attempting to load programs. A new API function is added to libbpf in order to pass the log_level from bpftool with the bpf_object__* part of the API. Options for a finer control over the log levels to use for libbpf and the verifier could be added in the future, if desired. v3: - Fix and clarify commit logs. v2: - Do not add distinct options for libbpf and verifier logs, just keep the one that sets all log levels to their maximum. Rename the option. - Do not offer a way to pick desired log levels. The choice is "use the option to print all logs" or "stick with the defaults". - Do not export BPF_LOG_* flags to user header. - Update all man pages (most bpftool operations use libbpf and may print libbpf logs). Verifier logs are only used when attempting to load programs for now, so bpftool-prog.rst and bpftool.rst remain the only pages updated in that regard. Previous discussion available at: https://lore.kernel.org/bpf/20190523105426.3938-1-quentin.monnet@netronome.com/ https://lore.kernel.org/bpf/20190429095227.9745-1-quentin.monnet@netronome.com/ ==================== Acked-by:
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Quentin Monnet authored
The "-d" option is used to require all logs available for bpftool. So far it meant telling libbpf to print even debug-level information. But there is another source of info that can be made more verbose: when we attemt to load programs with bpftool, we can pass a log_level parameter to the verifier in order to control the amount of information that is printed to the console. Reuse the "-d" option to print all information the verifier can tell. At this time, this means logs related to BPF_LOG_LEVEL1, BPF_LOG_LEVEL2 and BPF_LOG_STATS. As mentioned in the discussion on the first version of this set, these macros are internal to the kernel (include/linux/bpf_verifier.h) and are not meant to be part of the stable user API, therefore we simply use the related constants to print whatever we can at this time, without trying to tell users what is log_level1 or what is statistics. Verifier logs are only used when loading programs for now (In the future: for loading BTF objects with bpftool? Although libbpf does not currently offer to print verifier info at debug level if no error occurred when loading BTF objects), so bpftool.rst and bpftool-prog.rst are the only man pages to get the update. v3: - Add details on log level and BTF loading at the end of commit log. v2: - Remove the possibility to select the log levels to use (v1 offered a combination of "log_level1", "log_level2" and "stats"). - The macros from kernel header bpf_verifier.h are not used (and therefore not moved to UAPI header). - In v1 this was a distinct option, but is now merged in the only "-d" switch to activate libbpf and verifier debug-level logs all at the same time. Signed-off-by:
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Quentin Monnet authored
libbpf was recently made aware of the log_level attribute for programs, used to specify the level of information expected to be dumped by the verifier. Function bpf_prog_load_xattr() got support for this log_level parameter. But some applications using libbpf rely on another function to load programs, bpf_object__load(), which does accept any parameter for log level. Create an API function based on bpf_object__load(), but accepting an "attr" object as a parameter. Then add a log_level field to that object, so that applications calling the new bpf_object__load_xattr() can pick the desired log level. v3: - Rewrite commit log. v2: - We are in a new cycle, bump libbpf extraversion number. Signed-off-by:
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Quentin Monnet authored
libbpf has three levels of priority for output messages: warn, info, debug. By default, debug output is not printed to the console. Add a new "--debug" (short name: "-d") option to bpftool to print libbpf logs for all three levels. Internally, we simply use the function provided by libbpf to replace the default printing function by one that prints logs regardless of their level. v2: - Remove the possibility to select the log-levels to use (v1 offered a combination of "warn", "info" and "debug"). - Rename option and offer a short name: -d|--debug. - Add option description to all bpftool manual pages (instead of bpftool-prog.rst only), as all commands use libbpf. Signed-off-by:
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