- 17 Jan, 2020 10 commits
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KP Singh authored
As more programs (TRACING, STRUCT_OPS, and upcoming LSM) use vmlinux BTF information, loading the BTF vmlinux information for every program in an object is sub-optimal. The fix was originally proposed in: https://lore.kernel.org/bpf/CAEf4BzZodr3LKJuM7QwD38BiEH02Cc1UbtnGpVkCJ00Mf+V_Qg@mail.gmail.com/ The btf_vmlinux is populated in the object if any of the programs in the object requires it just before the programs are loaded and freed after the programs finish loading. Reported-by:
Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by:
KP Singh <kpsingh@google.com> Signed-off-by:
Alexei Starovoitov <ast@kernel.org> Reviewed-by:
Brendan Jackman <jackmanb@chromium.org> Acked-by:
Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200117212825.11755-1-kpsingh@chromium.org
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Andrii Nakryiko authored
Prevent potential overflow performed in 32-bit integers, before assigning result to size_t. Reported by LGTM static analysis. Fixes: eba9c5f4 ("libbpf: Refactor global data map initialization") Signed-off-by:
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Andrii Nakryiko authored
Current implementation of bpf_object's BTF initialization is very convoluted and thus prone to errors. It doesn't have to be like that. This patch simplifies it significantly. This code also triggered static analysis issues over logically dead code due to redundant error checks. This simplification should fix that as well. Signed-off-by:
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Andrii Nakryiko authored
Fix missing jump to error handling in btf_dump__new, found by Coverity static code analysis. Fixes: 9f81654e ("libbpf: Expose BTF-to-C type declaration emitting API") Signed-off-by:
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YueHaibing authored
kernel/bpf/syscall.c: In function generic_map_lookup_batch: kernel/bpf/syscall.c:1339:7: warning: variable first_key set but not used [-Wunused-but-set-variable] It is never used, so remove it. Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
YueHaibing <yuehaibing@huawei.com> Signed-off-by:
Brian Vazquez <brianvv@google.com> Link: https://lore.kernel.org/bpf/20200116145300.59056-1-yuehaibing@huawei.com
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Alexei Starovoitov authored
Toke Høiland-Jørgensen says: ==================== Since commit 96360004 ("xdp: Make devmap flush_list common for all map instances"), devmap flushing is a global operation instead of tied to a particular map. This means that with a bit of refactoring, we can finally fix the performance delta between the bpf_redirect_map() and bpf_redirect() helper functions, by introducing bulking for the latter as well. This series makes this change by moving the data structure used for the bulking into struct net_device itself, so we can access it even when there is not devmap. Once this is done, moving the bpf_redirect() helper to use the bulking mechanism becomes quite trivial, and brings bpf_redirect() up to the same as bpf_redirect_map(): Before: After: 1 CPU: bpf_redirect_map: 8.4 Mpps 8.4 Mpps (no change) bpf_redirect: 5.0 Mpps 8.4 Mpps (+68%) 2 CPUs: bpf_redirect_map: 15.9 Mpps 16.1 Mpps (+1% or ~no change) bpf_redirect: 9.5 Mpps 15.9 Mpps (+67%) After this patch series, the only semantics different between the two variants of the bpf() helper (apart from the absence of a map argument, obviously) is that the _map() variant will return an error if passed an invalid map index, whereas the bpf_redirect() helper will succeed, but drop packets on xdp_do_redirect(). This is because the helper has no reference to the calling netdev, so unfortunately we can't do the ifindex lookup directly in the helper. Changelog: v3: - Switch two more fields to avoid a list_head spanning two cache lines - Include Jesper's tracepoint patch - Also rename xdp_do_flush_map() - Fix a few nits from Maciej v2: - Consolidate code paths and tracepoints for map and non-map redirect variants (Björn) - Add performance data for 2-CPU test (Jesper) - Move fields to avoid shifting cache lines in struct net_device (Eric) ==================== Signed-off-by:
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Jesper Dangaard Brouer authored
Now that we don't have a reference to a devmap when flushing the device bulk queue, let's change the the devmap_xmit tracepoint to remote the map_id and map_index fields entirely. Rearrange the fields so 'drops' and 'sent' stay in the same position in the tracepoint struct, to make it possible for the xdp_monitor utility to read both the old and the new format. Signed-off-by:
Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by:
Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by:
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Toke Høiland-Jørgensen authored
Since the bulk queue used by XDP_REDIRECT now lives in struct net_device, we can re-use the bulking for the non-map version of the bpf_redirect() helper. This is a simple matter of having xdp_do_redirect_slow() queue the frame on the bulk queue instead of sending it out with __bpf_tx_xdp(). Unfortunately we can't make the bpf_redirect() helper return an error if the ifindex doesn't exit (as bpf_redirect_map() does), because we don't have a reference to the network namespace of the ingress device at the time the helper is called. So we have to leave it as-is and keep the device lookup in xdp_do_redirect_slow(). Since this leaves less reason to have the non-map redirect code in a separate function, so we get rid of the xdp_do_redirect_slow() function entirely. This does lose us the tracepoint disambiguation, but fortunately the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint entry structures. This means both can contain a map index, so we can just amend the tracepoint definitions so we always emit the xdp_redirect(_err) tracepoints, but with the map ID only populated if a map is present. This means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep the definitions around in case someone is still listening for them. With this change, the performance of the xdp_redirect sample program goes from 5Mpps to 8.4Mpps (a 68% increase). Since the flush functions are no longer map-specific, rename the flush() functions to drop _map from their names. One of the renamed functions is the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To keep from having to update all drivers, use a #define to keep the old name working, and only update the virtual drivers in this patch. Signed-off-by:
John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
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Toke Høiland-Jørgensen authored
Commit 96360004 ("xdp: Make devmap flush_list common for all map instances"), changed devmap flushing to be a global operation instead of a per-map operation. However, the queue structure used for bulking was still allocated as part of the containing map. This patch moves the devmap bulk queue into struct net_device. The motivation for this is reusing it for the non-map variant of XDP_REDIRECT, which will be changed in a subsequent commit. To avoid other fields of struct net_device moving to different cache lines, we also move a couple of other members around. We defer the actual allocation of the bulk queue structure until the NETDEV_REGISTER notification devmap.c. This makes it possible to check for ndo_xdp_xmit support before allocating the structure, which is not possible at the time struct net_device is allocated. However, we keep the freeing in free_netdev() to avoid adding another RCU callback on NETDEV_UNREGISTER. Because of this change, we lose the reference back to the map that originated the redirect, so change the tracepoint to always return 0 as the map ID and index. Otherwise no functional change is intended with this patch. After this patch, the relevant part of struct net_device looks like this, according to pahole: /* --- cacheline 14 boundary (896 bytes) --- */ struct netdev_queue * _tx __attribute__((__aligned__(64))); /* 896 8 */ unsigned int num_tx_queues; /* 904 4 */ unsigned int real_num_tx_queues; /* 908 4 */ struct Qdisc * qdisc; /* 912 8 */ unsigned int tx_queue_len; /* 920 4 */ spinlock_t tx_global_lock; /* 924 4 */ struct xdp_dev_bulk_queue * xdp_bulkq; /* 928 8 */ struct xps_dev_maps * xps_cpus_map; /* 936 8 */ struct xps_dev_maps * xps_rxqs_map; /* 944 8 */ struct mini_Qdisc * miniq_egress; /* 952 8 */ /* --- cacheline 15 boundary (960 bytes) --- */ struct hlist_head qdisc_hash[16]; /* 960 128 */ /* --- cacheline 17 boundary (1088 bytes) --- */ struct timer_list watchdog_timer; /* 1088 40 */ /* XXX last struct has 4 bytes of padding */ int watchdog_timeo; /* 1128 4 */ /* XXX 4 bytes hole, try to pack */ struct list_head todo_list; /* 1136 16 */ /* --- cacheline 18 boundary (1152 bytes) --- */ Signed-off-by:
Björn Töpel <bjorn.topel@intel.com> Acked-by:
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Andrii Nakryiko authored
Revert bpf_helpers.h's change to include auto-generated bpf_helper_defs.h through <> instead of "", which causes it to be searched in include path. This can break existing applications that don't have their include path pointing directly to where libbpf installs its headers. There is ongoing work to make all (not just bpf_helper_defs.h) includes more consistent across libbpf and its consumers, but this unbreaks user code as is right now without any regressions. Selftests still behave sub-optimally (taking bpf_helper_defs.h from libbpf's source directory, if it's present there), which will be fixed in subsequent patches. Fixes: 6910d7d3 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Reported-by:
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- 16 Jan, 2020 3 commits
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Yonghong Song authored
Alexei observed that test_progs send_signal may fail if run with command line "./test_progs" and the tests will pass if just run "./test_progs -n 40". I observed similar issue with nmi subtest failure and added a delay 100 us in Commit ab8b7f0c ("tools/bpf: Add self tests for bpf_send_signal_thread()") and the problem is gone for me. But the issue still exists in Alexei's testing environment. The current code uses sample_freq = 50 (50 events/second), which may not be enough. But if the sample_freq value is larger than sysctl kernel/perf_event_max_sample_rate, the perf_event_open syscall will fail. This patch changed nmi perf testing to use sample_period = 1, which means trying to sampling every event. This seems fixing the issue. Fixes: ab8b7f0c ("tools/bpf: Add self tests for bpf_send_signal_thread()") Signed-off-by:
Yonghong Song <yhs@fb.com> Signed-off-by:
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Brian Vazquez authored
bpf_attr doesn't required to be declared with '= {}' as memset is used in the code. Fixes: 2ab3d86e ("libbpf: Add libbpf support to batch ops") Reported-by:Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200116045918.75597-1-brianvv@google.com
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Andrii Nakryiko authored
Add ability to specify a list of test name substrings for selecting which tests to run. So now -t is accepting a comma-separated list of strings, similarly to how -n accepts a comma-separated list of test numbers. Additionally, add ability to blacklist tests by name. Blacklist takes precedence over whitelist. Blacklisting is important for cases where it's known that some tests can't pass (e.g., due to perf hardware events that are not available within VM). This is going to be used for libbpf testing in Travis CI in its Github repo. Example runs with just whitelist and whitelist + blacklist: $ sudo ./test_progs -tattach,core/existence #1 attach_probe:OK #6 cgroup_attach_autodetach:OK #7 cgroup_attach_multi:OK #8 cgroup_attach_override:OK #9 core_extern:OK #10/44 existence:OK #10/45 existence___minimal:OK #10/46 existence__err_int_sz:OK #10/47 existence__err_int_type:OK #10/48 existence__err_int_kind:OK #10/49 existence__err_arr_kind:OK #10/50 existence__err_arr_value_type:OK #10/51 existence__err_struct_type:OK #10 core_reloc:OK #19 flow_dissector_reattach:OK #60 tp_attach_query:OK Summary: 8/8 PASSED, 0 SKIPPED, 0 FAILED $ sudo ./test_progs -tattach,core/existence -bcgroup,flow/arr #1 attach_probe:OK #9 core_extern:OK #10/44 existence:OK #10/45 existence___minimal:OK #10/46 existence__err_int_sz:OK #10/47 existence__err_int_type:OK #10/48 existence__err_int_kind:OK #10/51 existence__err_struct_type:OK #10 core_reloc:OK #60 tp_attach_query:OK Summary: 4/6 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by:
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- 15 Jan, 2020 22 commits
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Alexei Starovoitov authored
Martin Lau says: ==================== When a map is storing a kernel's struct, its map_info->btf_vmlinux_value_type_id is set. The first map type supporting it is BPF_MAP_TYPE_STRUCT_OPS. This series adds support to dump this kind of map with BTF. The first two patches are bug fixes which are only applicable to bpf-next. Please see individual patches for details. v3: - Remove unnecessary #include "libbpf_internal.h" from patch 5 v2: - Expose bpf_find_kernel_btf() as a LIBBPF_API in patch 3 (Andrii) - Cache btf_vmlinux in bpftool/map.c (Andrii) ==================== Signed-off-by: -
Martin KaFai Lau authored
This patch makes bpftool support dumping a map's value properly when the map's value type is a type of the running kernel's btf. (i.e. map_info.btf_vmlinux_value_type_id is set instead of map_info.btf_value_type_id). The first usecase is for the BPF_MAP_TYPE_STRUCT_OPS. Signed-off-by:
Martin KaFai Lau <kafai@fb.com> Signed-off-by:
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Martin KaFai Lau authored
This patch adds BPF_MAP_TYPE_STRUCT_OPS to "struct_ops" name mapping so that "bpftool map show" can print the "struct_ops" map type properly. [root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool map show id 8 8: struct_ops name dctcp flags 0x0 key 4B value 256B max_entries 1 memlock 4096B btf_id 7 Signed-off-by:
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Martin KaFai Lau authored
This patch exposes bpf_find_kernel_btf() as a LIBBPF_API. It will be used in 'bpftool map dump' in a following patch to dump a map with btf_vmlinux_value_type_id set. bpf_find_kernel_btf() is renamed to libbpf_find_kernel_btf() and moved to btf.c. As <linux/kernel.h> is included, some of the max/min type casting needs to be fixed. Signed-off-by:
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Martin KaFai Lau authored
The btf availability check is only done for plain text output. It causes the whole BTF output went missing when json_output is used. This patch simplifies the logic a little by avoiding passing "int btf" to map_dump(). For plain text output, the btf_wtr is only created when the map has BTF (i.e. info->btf_id != 0). The nullness of "json_writer_t *wtr" in map_dump() alone can decide if dumping BTF output is needed. As long as wtr is not NULL, map_dump() will print out the BTF-described data whenever a map has BTF available (i.e. info->btf_id != 0) regardless of json or plain-text output. In do_dump(), the "int btf" is also renamed to "int do_plain_btf". Fixes: 99f9863a ("bpftool: Match maps by name") Signed-off-by:
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Martin KaFai Lau authored
When testing a map has btf or not, maps_have_btf() tests it by actually getting a btf_fd from sys_bpf(BPF_BTF_GET_FD_BY_ID). However, it forgot to btf__free() it. In maps_have_btf() stage, there is no need to test it by really calling sys_bpf(BPF_BTF_GET_FD_BY_ID). Testing non zero info.btf_id is good enough. Also, the err_close case is unnecessary, and also causes double close() because the calling func do_dump() will close() all fds again. Fixes: 99f9863a ("bpftool: Match maps by name") Signed-off-by:
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Alexei Starovoitov authored
Brian Vazquez says: ==================== This patch series introduce batch ops that can be added to bpf maps to lookup/lookup_and_delete/update/delete more than 1 element at the time, this is specially useful when syscall overhead is a problem and in case of hmap it will provide a reliable way of traversing them. The implementation inclues a generic approach that could potentially be used by any bpf map and adds it to arraymap, it also includes the specific implementation of hashmaps which are traversed using buckets instead of keys. The bpf syscall subcommands introduced are: BPF_MAP_LOOKUP_BATCH BPF_MAP_LOOKUP_AND_DELETE_BATCH BPF_MAP_UPDATE_BATCH BPF_MAP_DELETE_BATCH The UAPI attribute is: struct { /* struct used by BPF_MAP_*_BATCH commands */ __aligned_u64 in_batch; /* start batch, * NULL to start from beginning */ __aligned_u64 out_batch; /* output: next start batch */ __aligned_u64 keys; __aligned_u64 values; __u32 count; /* input/output: * input: # of key/value * elements * output: # of filled elements */ __u32 map_fd; __u64 elem_flags; __u64 flags; } batch; in_batch and out_batch are only used for lookup and lookup_and_delete since those are the only two operations that attempt to traverse the map. update/delete batch ops should provide the keys/values that user wants to modify. Here are the previous discussions on the batch processing: - https://lore.kernel.org/bpf/20190724165803.87470-1-brianvv@google.com/ - https://lore.kernel.org/bpf/20190829064502.2750303-1-yhs@fb.com/ - https://lore.kernel.org/bpf/20190906225434.3635421-1-yhs@fb.com/ Changelog sinve v4: - Remove unnecessary checks from libbpf API (Andrii Nakryiko) - Move DECLARE_LIBBPF_OPTS with all var declarations (Andrii Nakryiko) - Change bucket internal buffer size to 5 entries (Yonghong Song) - Fix some minor bugs in hashtab batch ops implementation (Yonghong Song) Changelog sinve v3: - Do not use copy_to_user inside atomic region (Yonghong Song) - Use _opts approach on libbpf APIs (Andrii Nakryiko) - Drop generic_map_lookup_and_delete_batch support - Free malloc-ed memory in tests (Yonghong Song) - Reverse christmas tree (Yonghong Song) - Add acked labels Changelog sinve v2: - Add generic batch support for lpm_trie and test it (Yonghong Song) - Use define MAP_LOOKUP_RETRIES for retries (John Fastabend) - Return errors directly and remove labels (Yonghong Song) - Insert new API functions into libbpf alphabetically (Yonghong Song) - Change hlist_nulls_for_each_entry_rcu to hlist_nulls_for_each_entry_safe in htab batch ops (Yonghong Song) Changelog since v1: - Fix SOB ordering and remove Co-authored-by tag (Alexei Starovoitov) Changelog since RFC: - Change batch to in_batch and out_batch to support more flexible opaque values to iterate the bpf maps. - Remove update/delete specific batch ops for htab and use the generic implementations instead. ==================== Acked-by: -
Brian Vazquez authored
Tested bpf_map_lookup_batch() and bpf_map_update_batch() functionality. $ ./test_maps ... test_array_map_batch_ops:PASS ... Signed-off-by: -
Yonghong Song authored
Tested bpf_map_lookup_batch(), bpf_map_lookup_and_delete_batch(), bpf_map_update_batch(), and bpf_map_delete_batch() functionality. $ ./test_maps ... test_htab_map_batch_ops:PASS test_htab_percpu_map_batch_ops:PASS ... Signed-off-by: -
Yonghong Song authored
Added four libbpf API functions to support map batch operations: . int bpf_map_delete_batch( ... ) . int bpf_map_lookup_batch( ... ) . int bpf_map_lookup_and_delete_batch( ... ) . int bpf_map_update_batch( ... ) Signed-off-by:
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Yonghong Song authored
sync uapi header include/uapi/linux/bpf.h to tools/include/uapi/linux/bpf.h Signed-off-by:
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Yonghong Song authored
htab can't use generic batch support due some problematic behaviours inherent to the data structre, i.e. while iterating the bpf map a concurrent program might delete the next entry that batch was about to use, in that case there's no easy solution to retrieve the next entry, the issue has been discussed multiple times (see [1] and [2]). The only way hmap can be traversed without the problem previously exposed is by making sure that the map is traversing entire buckets. This commit implements those strict requirements for hmap, the implementation follows the same interaction that generic support with some exceptions: - If keys/values buffer are not big enough to traverse a bucket, ENOSPC will be returned. - out_batch contains the value of the next bucket in the iteration, not the next key, but this is transparent for the user since the user should never use out_batch for other than bpf batch syscalls. This commits implements BPF_MAP_LOOKUP_BATCH and adds support for new command BPF_MAP_LOOKUP_AND_DELETE_BATCH. Note that for update/delete batch ops it is possible to use the generic implementations. [1] https://lore.kernel.org/bpf/20190724165803.87470-1-brianvv@google.com/ [2] https://lore.kernel.org/bpf/20190906225434.3635421-1-yhs@fb.com/Signed-off-by:
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Brian Vazquez authored
This adds the generic batch ops functionality to bpf arraymap, note that since deletion is not a valid operation for arraymap, only batch and lookup are added. Signed-off-by:
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Brian Vazquez authored
This commit adds generic support for update and delete batch ops that can be used for almost all the bpf maps. These commands share the same UAPI attr that lookup and lookup_and_delete batch ops use and the syscall commands are: BPF_MAP_UPDATE_BATCH BPF_MAP_DELETE_BATCH The main difference between update/delete and lookup batch ops is that for update/delete keys/values must be specified for userspace and because of that, neither in_batch nor out_batch are used. Suggested-by:
Stanislav Fomichev <sdf@google.com> Signed-off-by:
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Brian Vazquez authored
This commit introduces generic support for the bpf_map_lookup_batch. This implementation can be used by almost all the bpf maps since its core implementation is relying on the existing map_get_next_key and map_lookup_elem. The bpf syscall subcommand introduced is: BPF_MAP_LOOKUP_BATCH The UAPI attribute is: struct { /* struct used by BPF_MAP_*_BATCH commands */ __aligned_u64 in_batch; /* start batch, * NULL to start from beginning */ __aligned_u64 out_batch; /* output: next start batch */ __aligned_u64 keys; __aligned_u64 values; __u32 count; /* input/output: * input: # of key/value * elements * output: # of filled elements */ __u32 map_fd; __u64 elem_flags; __u64 flags; } batch; in_batch/out_batch are opaque values use to communicate between user/kernel space, in_batch/out_batch must be of key_size length. To start iterating from the beginning in_batch must be null, count is the # of key/value elements to retrieve. Note that the 'keys' buffer must be a buffer of key_size * count size and the 'values' buffer must be value_size * count, where value_size must be aligned to 8 bytes by userspace if it's dealing with percpu maps. 'count' will contain the number of keys/values successfully retrieved. Note that 'count' is an input/output variable and it can contain a lower value after a call. If there's no more entries to retrieve, ENOENT will be returned. If error is ENOENT, count might be > 0 in case it copied some values but there were no more entries to retrieve. Note that if the return code is an error and not -EFAULT, count indicates the number of elements successfully processed. Suggested-by: -
Brian Vazquez authored
This commit moves reusable code from map_lookup_elem and map_update_elem to avoid code duplication in kernel/bpf/syscall.c. Signed-off-by:
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Eelco Chaudron authored
Add a test that will attach a FENTRY and FEXIT program to the XDP test program. It will also verify data from the XDP context on FENTRY and verifies the return code on exit. Signed-off-by:
Eelco Chaudron <echaudro@redhat.com> Signed-off-by:
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Andrii Nakryiko authored
The LLVM patch https://reviews.llvm.org/D72197 makes LLVM emit function call relocations within the same section. This includes a default .text section, which contains any BPF sub-programs. This wasn't the case before and so libbpf was able to get a way with slightly simpler handling of subprogram call relocations. This patch adds support for .text section relocations. It needs to ensure correct order of relocations, so does two passes: - first, relocate .text instructions, if there are any relocations in it; - then process all the other programs and copy over patched .text instructions for all sub-program calls. v1->v2: - break early once .text program is processed. Signed-off-by:
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Alexei Starovoitov authored
Yonghong Song says: ==================== Commit 8b401f9e ("bpf: implement bpf_send_signal() helper") added helper bpf_send_signal() which permits bpf program to send a signal to the current process. The signal may send to any thread of the process. This patch implemented a new helper bpf_send_signal_thread() to send a signal to the thread corresponding to the kernel current task. This helper can simplify user space code if the thread context of bpf sending signal is needed in user space. Please see Patch #1 for details of use case and kernel implementation. Patch #2 added some bpf self tests for the new helper. Changelogs: v2 -> v3: - More simplification for skeleton codes by removing not-needed mmap code and redundantly created tracepoint link. v1 -> v2: - More description for the difference between bpf_send_signal() and bpf_send_signal_thread() in the uapi header bpf.h. - Use skeleton and mmap for send_signal test. ==================== Acked-by:
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Yonghong Song authored
The test_progs send_signal() is amended to test bpf_send_signal_thread() as well. $ ./test_progs -n 40 #40/1 send_signal_tracepoint:OK #40/2 send_signal_perf:OK #40/3 send_signal_nmi:OK #40/4 send_signal_tracepoint_thread:OK #40/5 send_signal_perf_thread:OK #40/6 send_signal_nmi_thread:OK #40 send_signal:OK Summary: 1/6 PASSED, 0 SKIPPED, 0 FAILED Also took this opportunity to rewrite the send_signal test using skeleton framework and array mmap to make code simpler and more readable. Signed-off-by:
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Yonghong Song authored
Commit 8b401f9e ("bpf: implement bpf_send_signal() helper") added helper bpf_send_signal() which permits bpf program to send a signal to the current process. The signal may be delivered to any threads in the process. We found a use case where sending the signal to the current thread is more preferable. - A bpf program will collect the stack trace and then send signal to the user application. - The user application will add some thread specific information to the just collected stack trace for later analysis. If bpf_send_signal() is used, user application will need to check whether the thread receiving the signal matches the thread collecting the stack by checking thread id. If not, it will need to send signal to another thread through pthread_kill(). This patch proposed a new helper bpf_send_signal_thread(), which sends the signal to the thread corresponding to the current kernel task. This way, user space is guaranteed that bpf_program execution context and user space signal handling context are the same thread. Signed-off-by:
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Magnus Karlsson authored
When registering a umem area that is sufficiently large (>1G on an x86), kmalloc cannot be used to allocate one of the internal data structures, as the size requested gets too large. Use kvmalloc instead that falls back on vmalloc if the allocation is too large for kmalloc. Also add accounting for this structure as it is triggered by a user space action (the XDP_UMEM_REG setsockopt) and it is by far the largest structure of kernel allocated memory in xsk. Reported-by:
Ryan Goodfellow <rgoodfel@isi.edu> Signed-off-by:
Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by:
Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/1578995365-7050-1-git-send-email-magnus.karlsson@intel.com
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- 14 Jan, 2020 5 commits
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Li RongQing authored
A negative value should be returned if map->map_type is invalid although that is impossible now, but if we run into such situation in future, then xdpbuff could be leaked. Daniel Borkmann suggested: -EBADRQC should be returned to stay consistent with generic XDP for the tracepoint output and not to be confused with -EOPNOTSUPP from other locations like dev_map_enqueue() when ndo_xdp_xmit is missing and such. Suggested-by:
Li RongQing <lirongqing@baidu.com> Signed-off-by:
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Martin KaFai Lau authored
Instead of using bpf_struct_ops_map_lookup_elem() which is not implemented, bpf_struct_ops_map_seq_show_elem() should also use bpf_struct_ops_map_sys_lookup_elem() which does an inplace update to the value. The change allocates a value to pass to bpf_struct_ops_map_sys_lookup_elem(). [root@arch-fb-vm1 bpf]# cat /sys/fs/bpf/dctcp {{{1}},BPF_STRUCT_OPS_STATE_INUSE,{{00000000df93eebc,00000000df93eebc},0,2, ... Fixes: 85d33df3 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS") Reported-by:Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Alexei Starovoitov authored
Andrii Nakryiko says: ==================== Based on recent BPF CO-RE, tp_btf, and BPF skeleton changes, re-implement BCC-based runqslower tool as a portable pre-compiled BPF CO-RE-based tool. Make sure it's built as part of selftests to ensure it doesn't bit rot. As part of this patch set, augment `format c` output of `bpftool btf dump` sub-command with applying `preserve_access_index` attribute to all structs and unions. This makes all such structs and unions automatically relocatable under BPF CO-RE, which improves user experience of writing TRACING programs with direct kernel memory read access. Also, further clean up selftest/bpf Makefile output and make it conforming to libbpf and bpftool succinct output format. v1->v2: - build in-tree bpftool for runqslower (Yonghong); - drop `format core` and augment `format c` instead (Alexei); - move runqslower under tools/bpf (Daniel). ==================== Signed-off-by: -
Andrii Nakryiko authored
Ensure runqslower tool is built as part of selftests to prevent it from bit rotting. Signed-off-by:
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Andrii Nakryiko authored
Convert one of BCC tools (runqslower [0]) to BPF CO-RE + libbpf. It matches its BCC-based counterpart 1-to-1, supporting all the same parameters and functionality. runqslower tool utilizes BPF skeleton, auto-generated from BPF object file, as well as memory-mapped interface to global (read-only, in this case) data. Its Makefile also ensures auto-generation of "relocatable" vmlinux.h, which is necessary for BTF-typed raw tracepoints with direct memory access. [0] https://github.com/iovisor/bcc/blob/11bf5d02c895df9646c117c713082eb192825293/tools/runqslower.pySigned-off-by:
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