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2024-10-24selftests/bpf: Create task_local_storage map with invalid uptr's structMartin KaFai Lau
This patch tests the map creation failure when the map_value has unsupported uptr. The three cases are the struct is larger than one page, the struct is empty, and the struct is a kernel struct. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-13-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24selftests/bpf: Add uptr failure verifier testsMartin KaFai Lau
Add verifier tests to ensure invalid uptr usages are rejected. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-12-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24selftests/bpf: Add update_elem failure test for task storage uptrMartin KaFai Lau
This patch test the following failures in syscall update_elem 1. The first update_elem(BPF_F_LOCK) should be EOPNOTSUPP. syscall.c takes care of unpinning the uptr. 2. The second update_elem(BPF_EXIST) fails. syscall.c takes care of unpinning the uptr. 3. The forth update_elem(BPF_NOEXIST) fails. bpf_local_storage_update takes care of unpinning the uptr. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-11-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24selftests/bpf: Test a uptr struct spanning across pages.Martin KaFai Lau
This patch tests the case when uptr has a struct spanning across two pages. It is not supported now and EOPNOTSUPP is expected from the syscall update_elem. It also tests the whole uptr struct located exactly at the end of a page and ensures that this case is accepted by update_elem. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-10-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24selftests/bpf: Some basic __uptr testsKui-Feng Lee
Make sure the memory of uptrs have been mapped to the kernel properly. Also ensure the values of uptrs in the kernel haven't been copied to userspace. It also has the syscall update_elem/delete_elem test to test the pin/unpin code paths. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-9-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24libbpf: define __uptr.Kui-Feng Lee
Make __uptr available to BPF programs to enable them to define uptrs. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-8-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24bpf: Add uptr support in the map_value of the task local storage.Martin KaFai Lau
This patch adds uptr support in the map_value of the task local storage. struct map_value { struct user_data __uptr *uptr; }; struct { __uint(type, BPF_MAP_TYPE_TASK_STORAGE); __uint(map_flags, BPF_F_NO_PREALLOC); __type(key, int); __type(value, struct value_type); } datamap SEC(".maps"); A new bpf_obj_pin_uptrs() is added to pin the user page and also stores the kernel address back to the uptr for the bpf prog to use later. It currently does not support the uptr pointing to a user struct across two pages. It also excludes PageHighMem support to keep it simple. As of now, the 32bit bpf jit is missing other more crucial bpf features. For example, many important bpf features depend on bpf kfunc now but so far only one arch (x86-32) supports it which was added by me as an example when kfunc was first introduced to bpf. The uptr can only be stored to the task local storage by the syscall update_elem. Meaning the uptr will not be considered if it is provided by the bpf prog through bpf_task_storage_get(BPF_LOCAL_STORAGE_GET_F_CREATE). This is enforced by only calling bpf_local_storage_update(swap_uptrs==true) in bpf_pid_task_storage_update_elem. Everywhere else will have swap_uptrs==false. This will pump down to bpf_selem_alloc(swap_uptrs==true). It is the only case that bpf_selem_alloc() will take the uptr value when updating the newly allocated selem. bpf_obj_swap_uptrs() is added to swap the uptr between the SDATA(selem)->data and the user provided map_value in "void *value". bpf_obj_swap_uptrs() makes the SDATA(selem)->data takes the ownership of the uptr and the user space provided map_value will have NULL in the uptr. The bpf_obj_unpin_uptrs() is called after map->ops->map_update_elem() returning error. If the map->ops->map_update_elem has reached a state that the local storage has taken the uptr ownership, the bpf_obj_unpin_uptrs() will be a no op because the uptr is NULL. A "__"bpf_obj_unpin_uptrs is added to make this error path unpin easier such that it does not have to check the map->record is NULL or not. BPF_F_LOCK is not supported when the map_value has uptr. This can be revisited later if there is a use case. A similar swap_uptrs idea can be considered. The final bit is to do unpin_user_page in the bpf_obj_free_fields(). The earlier patch has ensured that the bpf_obj_free_fields() has gone through the rcu gp when needed. Cc: linux-mm@kvack.org Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Link: https://lore.kernel.org/r/20241023234759.860539-7-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24bpf: Postpone bpf_obj_free_fields to the rcu callbackMartin KaFai Lau
A later patch will enable the uptr usage in the task_local_storage map. This will require the unpin_user_page() to be done after the rcu task trace gp for the cases that the uptr may still be used by a bpf prog. The bpf_obj_free_fields() will be the one doing unpin_user_page(), so this patch is to postpone calling bpf_obj_free_fields() to the rcu callback. The bpf_obj_free_fields() is only required to be done in the rcu callback when bpf->bpf_ma==true and reuse_now==false. bpf->bpf_ma==true case is because uptr will only be enabled in task storage which has already been moved to bpf_mem_alloc. The bpf->bpf_ma==false case can be supported in the future also if there is a need. reuse_now==false when the selem (aka storage) is deleted by bpf prog (bpf_task_storage_delete) or by syscall delete_elem(). In both cases, bpf_obj_free_fields() needs to wait for rcu gp. A few words on reuse_now==true. reuse_now==true when the storage's owner (i.e. the task_struct) is destructing or the map itself is doing map_free(). In both cases, no bpf prog should have a hold on the selem and its uptrs, so there is no need to postpone bpf_obj_free_fields(). reuse_now==true should be the common case for local storage usage where the storage exists throughout the lifetime of its owner (task_struct). The bpf_obj_free_fields() needs to use the map->record. Doing bpf_obj_free_fields() in a rcu callback will require the bpf_local_storage_map_free() to wait for rcu_barrier. An optimization could be only waiting for rcu_barrier when the map has uptr in its map_value. This will require either yet another rcu callback function or adding a bool in the selem to flag if the SDATA(selem)->smap is still valid. This patch chooses to keep it simple and wait for rcu_barrier for maps that use bpf_mem_alloc. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-6-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24bpf: Postpone bpf_selem_free() in bpf_selem_unlink_storage_nolock()Martin KaFai Lau
In a later patch, bpf_selem_free() will call unpin_user_page() through bpf_obj_free_fields(). unpin_user_page() may take spin_lock. However, some bpf_selem_free() call paths have held a raw_spin_lock. Like this: raw_spin_lock_irqsave() bpf_selem_unlink_storage_nolock() bpf_selem_free() unpin_user_page() spin_lock() To avoid spinlock nested in raw_spinlock, bpf_selem_free() should be done after releasing the raw_spinlock. The "bool reuse_now" arg is replaced with "struct hlist_head *free_selem_list" in bpf_selem_unlink_storage_nolock(). The bpf_selem_unlink_storage_nolock() will append the to-be-free selem at the free_selem_list. The caller of bpf_selem_unlink_storage_nolock() will need to call the new bpf_selem_free_list(free_selem_list, reuse_now) to free the selem after releasing the raw_spinlock. Note that the selem->snode cannot be reused for linking to the free_selem_list because the selem->snode is protected by the raw_spinlock that we want to avoid holding. A new "struct hlist_node free_node;" is union-ized with the rcu_head. Only the first one successfully hlist_del_init_rcu(&selem->snode) will be able to use the free_node. After succeeding hlist_del_init_rcu(&selem->snode), the free_node and rcu_head usage is serialized such that they can share the 16 bytes in a union. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-5-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24bpf: Add "bool swap_uptrs" arg to bpf_local_storage_update() and ↵Martin KaFai Lau
bpf_selem_alloc() In a later patch, the task local storage will only accept uptr from the syscall update_elem and will not accept uptr from the bpf prog. The reason is the bpf prog does not have a way to provide a valid user space address. bpf_local_storage_update() and bpf_selem_alloc() are used by both bpf prog bpf_task_storage_get(BPF_LOCAL_STORAGE_GET_F_CREATE) and bpf syscall update_elem. "bool swap_uptrs" arg is added to bpf_local_storage_update() and bpf_selem_alloc() to tell if it is called by the bpf prog or by the bpf syscall. When swap_uptrs==true, it is called by the syscall. The arg is named (swap_)uptrs because the later patch will swap the uptrs between the newly allocated selem and the user space provided map_value. It will make error handling easier in case map->ops->map_update_elem() fails and the caller can decide if it needs to unpin the uptr in the user space provided map_value or the bpf_local_storage_update() has already taken the uptr ownership and will take care of unpinning it also. Only swap_uptrs==false is passed now. The logic to handle the true case will be added in a later patch. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24bpf: Handle BPF_UPTR in verifierKui-Feng Lee
This patch adds BPF_UPTR support to the verifier. Not that only the map_value will support the "__uptr" type tag. This patch enforces only BPF_LDX is allowed to the value of an uptr. After BPF_LDX, it will mark the dst_reg as PTR_TO_MEM | PTR_MAYBE_NULL with size deduced from the field.kptr.btf_id. This will make the dst_reg pointed memory to be readable and writable as scalar. There is a redundant "val_reg = reg_state(env, value_regno);" statement in the check_map_kptr_access(). This patch takes this chance to remove it also. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-3-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24bpf: Support __uptr type tag in BTFKui-Feng Lee
This patch introduces the "__uptr" type tag to BTF. It is to define a pointer pointing to the user space memory. This patch adds BTF logic to pass the "__uptr" type tag. btf_find_kptr() is reused for the "__uptr" tag. The "__uptr" will only be supported in the map_value of the task storage map. However, btf_parse_struct_meta() also uses btf_find_kptr() but it is not interested in "__uptr". This patch adds a "field_mask" argument to btf_find_kptr() which will return BTF_FIELD_IGNORE if the caller is not interested in a “__uptr” field. btf_parse_kptr() is also reused to parse the uptr. The btf_check_and_fixup_fields() is changed to do extra checks on the uptr to ensure that its struct size is not larger than PAGE_SIZE. It is not clear how a uptr pointing to a CO-RE supported kernel struct will be used, so it is also not allowed now. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-2-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23Merge branch 'fix-libbpf-s-bpf_object-and-bpf-subskel-interoperability'Alexei Starovoitov
Andrii Nakryiko says: ==================== Fix libbpf's bpf_object and BPF subskel interoperability Fix libbpf's global data map mmap()'ing logic to make BPF objects loaded through generic bpf_object__load() API interoperable with BPF subskeleton instantiated from such BPF object. The issue is in re-mmap()'ing of global data maps after BPF object is loaded into kernel, which is currently done in BPF skeleton-specific code, and should instead be done in generic and common bpf_object_load() logic. See patch #2 for the fix, patch #3 for the selftests. Patch #1 is preliminary fix for existing spin_lock selftests which currently works by accident. ==================== Link: https://lore.kernel.org/r/20241023043908.3834423-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23selftests/bpf: validate generic bpf_object and subskel APIs work togetherAndrii Nakryiko
Add a new subtest validating that bpf_object loaded and initialized through generic APIs is still interoperable with BPF subskeleton, including initialization and reading of global variables. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241023043908.3834423-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23libbpf: move global data mmap()'ing into bpf_object__load()Andrii Nakryiko
Since BPF skeleton inception libbpf has been doing mmap()'ing of global data ARRAY maps in bpf_object__load_skeleton() API, which is used by code generated .skel.h files (i.e., by BPF skeletons only). This is wrong because if BPF object is loaded through generic bpf_object__load() API, global data maps won't be re-mmap()'ed after load step, and memory pointers returned from bpf_map__initial_value() would be wrong and won't reflect the actual memory shared between BPF program and user space. bpf_map__initial_value() return result is rarely used after load, so this went unnoticed for a really long time, until bpftrace project attempted to load BPF object through generic bpf_object__load() API and then used BPF subskeleton instantiated from such bpf_object. It turned out that .data/.rodata/.bss data updates through such subskeleton was "blackholed", all because libbpf wouldn't re-mmap() those maps during bpf_object__load() phase. Long story short, this step should be done by libbpf regardless of BPF skeleton usage, right after BPF map is created in the kernel. This patch moves this functionality into bpf_object__populate_internal_map() to achieve this. And bpf_object__load_skeleton() is now simple and almost trivial, only propagating these mmap()'ed pointers into user-supplied skeleton structs. We also do trivial adjustments to error reporting inside bpf_object__populate_internal_map() for consistency with the rest of libbpf's map-handling code. Reported-by: Alastair Robertson <ajor@meta.com> Reported-by: Jonathan Wiepert <jwiepert@meta.com> Fixes: d66562fba1ce ("libbpf: Add BPF object skeleton support") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241023043908.3834423-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23selftests/bpf: fix test_spin_lock_fail.c's global vars usageAndrii Nakryiko
Global variables of special types (like `struct bpf_spin_lock`) make underlying ARRAY maps non-mmapable. To make this work with libbpf's mmaping logic, application is expected to declare such special variables as static, so libbpf doesn't even attempt to mmap() such ARRAYs. test_spin_lock_fail.c didn't follow this rule, but given it relied on this test to trigger failures, this went unnoticed, as we never got to the step of mmap()'ing these ARRAY maps. It is fragile and relies on specific sequence of libbpf steps, which are an internal implementation details. Fix the test by marking lockA and lockB as static. Fixes: c48748aea4f8 ("selftests/bpf: Add failure test cases for spin lock pairing") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241023043908.3834423-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23Merge branch 'fix-wmaybe-uninitialized-warnings-errors'Andrii Nakryiko
Eder Zulian says: ==================== Fix -Wmaybe-uninitialized warnings/errors Hello! This v2 series initializes the variables 'set' and 'set8' in sets_patch to NULL, along with the variables 'new_off' and 'pad_bits' and 'pad_type' in btf_dump_emit_bit_padding to zero or NULL according to their types and the variable 'o' in options__order to NULL to prevent compiler warnings/errors which are observed when compiling with non-default compilation options, but are not emitted by the compiler with the current default compilation options. - tools/bpf/resolve_btfids/main.c: Initialize the variables 'set' and 'set8' in sets_patch to NULL. - tools/lib/bpf/btf_dump.c: Initialize the variables 'new_off' and 'pad_bits' and 'pad_type' in btf_dump_emit_bit_padding to zero/NULL - tools/lib/subcmd/parse-options.c: Initialize the variable 'o' in options__order to NULL. Sam James mentioned that Michael Weiß had previously sent an alternative patch as https://lore.kernel.org/all/20240731085217.94928-1-michael.weiss@aisec.fraunhofer.de/ Tested on x86_64 with clang version 17.0.6 and gcc (GCC) 13.3.1. $ for c in gcc clang; do for o in fast g s z $(seq 0 3); do make -C \ tools/bpf/resolve_btfids/ HOST_CC=${c} "HOSTCFLAGS=-O${o} -Wall" \ clean all 2>&1 | tee ${c}-O${o}.out; done; done && \ grep 'warning:\|error:' *.out [...] clang-O1.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] clang-O1.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] clang-O2.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] clang-O2.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] clang-O3.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] clang-O3.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] clang-Ofast.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] clang-Ofast.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] clang-Og.out:btf_dump.c:903:42: error: ‘new_off’ may be used uninitialized [-Werror=maybe-uninitialized] clang-Og.out:btf_dump.c:917:25: error: ‘pad_type’ may be used uninitialized [-Werror=maybe-uninitialized] clang-Og.out:btf_dump.c:930:20: error: ‘pad_bits’ may be used uninitialized [-Werror=maybe-uninitialized] clang-Os.out:parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized] clang-Oz.out:parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized] gcc-O1.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] gcc-O1.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] gcc-O2.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] gcc-O2.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] gcc-O3.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] gcc-O3.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] gcc-Ofast.out:main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] gcc-Ofast.out:main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] gcc-Og.out:btf_dump.c:903:42: error: ‘new_off’ may be used uninitialized [-Werror=maybe-uninitialized] gcc-Og.out:btf_dump.c:917:25: error: ‘pad_type’ may be used uninitialized [-Werror=maybe-uninitialized] gcc-Og.out:btf_dump.c:930:20: error: ‘pad_bits’ may be used uninitialized [-Werror=maybe-uninitialized] gcc-Os.out:parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized] gcc-Oz.out:parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized] The above warnings and/or errors are fixed. However, they are observed with current default compilation options. Updates since v1: - Incorporate feedback from reviewers. Add a comment about an alternative patch for parse-options.c sent before (based on comments from Sam James.) Split in multiple patches creating this series and a typo was fixed "Initiazlide" -> "Initialize" (suggested by Viktor Malik). State more clearly that the -Wmaybe-uninitialized issues only happen when compiling with non-default compilation options (based on comments from Yonghong Song.) Thanks, ==================== Link: https://lore.kernel.org/r/20241022172329.3871958-1-ezulian@redhat.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-10-23libsubcmd: Silence compiler warningEder Zulian
Initialize the pointer 'o' in options__order to NULL to prevent a compiler warning/error which is observed when compiling with the '-Og' option, but is not emitted by the compiler with the current default compilation options. For example, when compiling libsubcmd with $ make "EXTRA_CFLAGS=-Og" -C tools/lib/subcmd/ clean all Clang version 17.0.6 and GCC 13.3.1 fail to compile parse-options.c due to following error: parse-options.c: In function ‘options__order’: parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized] 832 | memcpy(&ordered[nr_opts], o, sizeof(*o)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ parse-options.c:810:30: note: ‘o’ was declared here 810 | const struct option *o, *p = opts; | ^ cc1: all warnings being treated as errors Signed-off-by: Eder Zulian <ezulian@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20241022172329.3871958-4-ezulian@redhat.com
2024-10-23libbpf: Prevent compiler warnings/errorsEder Zulian
Initialize 'new_off' and 'pad_bits' to 0 and 'pad_type' to NULL in btf_dump_emit_bit_padding to prevent compiler warnings/errors which are observed when compiling with 'EXTRA_CFLAGS=-g -Og' options, but do not happen when compiling with current default options. For example, when compiling libbpf with $ make "EXTRA_CFLAGS=-g -Og" -C tools/lib/bpf/ clean all Clang version 17.0.6 and GCC 13.3.1 fail to compile btf_dump.c due to following errors: btf_dump.c: In function ‘btf_dump_emit_bit_padding’: btf_dump.c:903:42: error: ‘new_off’ may be used uninitialized [-Werror=maybe-uninitialized] 903 | if (new_off > cur_off && new_off <= next_off) { | ~~~~~~~~^~~~~~~~~~~ btf_dump.c:870:13: note: ‘new_off’ was declared here 870 | int new_off, pad_bits, bits, i; | ^~~~~~~ btf_dump.c:917:25: error: ‘pad_type’ may be used uninitialized [-Werror=maybe-uninitialized] 917 | btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 918 | in_bitfield ? new_off - cur_off : 0); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ btf_dump.c:871:21: note: ‘pad_type’ was declared here 871 | const char *pad_type; | ^~~~~~~~ btf_dump.c:930:20: error: ‘pad_bits’ may be used uninitialized [-Werror=maybe-uninitialized] 930 | if (bits == pad_bits) { | ^ btf_dump.c:870:22: note: ‘pad_bits’ was declared here 870 | int new_off, pad_bits, bits, i; | ^~~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Eder Zulian <ezulian@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20241022172329.3871958-3-ezulian@redhat.com
2024-10-23resolve_btfids: Fix compiler warningsEder Zulian
Initialize 'set' and 'set8' pointers to NULL in sets_patch to prevent possible compiler warnings which are issued for various optimization levels, but do not happen when compiling with current default compilation options. For example, when compiling resolve_btfids with $ make "HOSTCFLAGS=-O2 -Wall" -C tools/bpf/resolve_btfids/ clean all Clang version 17.0.6 and GCC 13.3.1 issue following -Wmaybe-uninitialized warnings for variables 'set8' and 'set': In function ‘sets_patch’, inlined from ‘symbols_patch’ at main.c:748:6, inlined from ‘main’ at main.c:823:6: main.c:163:9: warning: ‘set8’ may be used uninitialized [-Wmaybe-uninitialized] 163 | eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:729:17: note: in expansion of macro ‘pr_debug’ 729 | pr_debug("sorting addr %5lu: cnt %6d [%s]\n", | ^~~~~~~~ main.c: In function ‘main’: main.c:682:37: note: ‘set8’ was declared here 682 | struct btf_id_set8 *set8; | ^~~~ In function ‘sets_patch’, inlined from ‘symbols_patch’ at main.c:748:6, inlined from ‘main’ at main.c:823:6: main.c:163:9: warning: ‘set’ may be used uninitialized [-Wmaybe-uninitialized] 163 | eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:729:17: note: in expansion of macro ‘pr_debug’ 729 | pr_debug("sorting addr %5lu: cnt %6d [%s]\n", | ^~~~~~~~ main.c: In function ‘main’: main.c:683:36: note: ‘set’ was declared here 683 | struct btf_id_set *set; | ^~~ Signed-off-by: Eder Zulian <ezulian@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20241022172329.3871958-2-ezulian@redhat.com
2024-10-23selftests/bpf: Increase verifier log limit in veristatMykyta Yatsenko
The current default buffer size of 16MB allocated by veristat is no longer sufficient to hold the verifier logs of some production BPF programs. To address this issue, we need to increase the verifier log limit. Commit 7a9f5c65abcc ("bpf: increase verifier log limit") has already increased the supported buffer size by the kernel, but veristat users need to explicitly pass a log size argument to use the bigger log. This patch adds a function to detect the maximum verifier log size supported by the kernel and uses that by default in veristat. This ensures that veristat can handle larger verifier logs without requiring users to manually specify the log size. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241023155314.126255-1-mykyta.yatsenko5@gmail.com
2024-10-22Merge branch 'Retire test_sock.c'Martin KaFai Lau
Jordan Rife says: ==================== This patch series migrates test cases out of test_sock.c to prog_tests-style tests. It moves all BPF_CGROUP_INET4_POST_BIND and BPF_CGROUP_INET6_POST_BIND test cases into a new prog_test, sock_post_bind.c, while reimplementing all LOAD_REJECT test cases as verifier tests in progs/verifier_sock.c. Finally, it moves remaining BPF_CGROUP_INET_SOCK_CREATE test coverage into prog_tests/sock_create.c before retiring test_sock.c completely. Changes ======= v1->v2: - Remove superfluous verbose bool from the top of sock_post_bind.c. - Use ASSERT_OK_FD instead of ASSERT_GE to test cgroup_fd validity. - Run sock_post_bind tests in their own namespace, "sock_post_bind". ==================== Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-10-22selftests/bpf: Retire test_sock.cJordan Rife
Completely remove test_sock.c and associated config. Signed-off-by: Jordan Rife <jrife@google.com> Link: https://lore.kernel.org/r/20241022152913.574836-5-jrife@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-10-22selftests/bpf: Migrate BPF_CGROUP_INET_SOCK_CREATE test cases to prog_testsJordan Rife
Move the "load w/o expected_attach_type" test case to prog_tests/sock_create.c and drop the remaining test case, as it is made redundant with the existing coverage inside prog_tests/sock_create.c. Signed-off-by: Jordan Rife <jrife@google.com> Link: https://lore.kernel.org/r/20241022152913.574836-4-jrife@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-10-22selftests/bpf: Migrate LOAD_REJECT test cases to prog_testsJordan Rife
Move LOAD_REJECT test cases from test_sock.c to an equivalent set of verifier tests in progs/verifier_sock.c. Signed-off-by: Jordan Rife <jrife@google.com> Link: https://lore.kernel.org/r/20241022152913.574836-3-jrife@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-10-22selftests/bpf: Migrate *_POST_BIND test cases to prog_testsJordan Rife
Move all BPF_CGROUP_INET6_POST_BIND and BPF_CGROUP_INET4_POST_BIND test cases to a new prog_test, prog_tests/sock_post_bind.c, except for LOAD_REJECT test cases. Signed-off-by: Jordan Rife <jrife@google.com> Link: https://lore.kernel.org/r/20241022152913.574836-2-jrife@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-10-21Merge branch 'implement-mechanism-to-signal-other-threads'Andrii Nakryiko
Puranjay Mohan says: ==================== Implement mechanism to signal other threads This set implements a kfunc called bpf_send_signal_task() that is similar to sigqueue() as it can send a signal along with a cookie to a thread or thread group. The send_signal selftest has been updated to also test this new kfunc under all contexts. Changes in v5: v4: https://lore.kernel.org/all/20241008114940.44305-1-puranjay@kernel.org/ - Call copy_siginfo() only if work->has_siginfo is true in bpf_send_signal_common() - Add Acked-by: Andrii Nakryiko <andrii@kernel.org> Changes in v4: v3: https://lore.kernel.org/all/20241007103426.128923-1-puranjay@kernel.org/ - Fix the selftest to make it work for big-endian archs. - Fix a build warning on 32-bit archs. - Some style changes and code refactors suggested by Andrii Changes in v3: v2: https://lore.kernel.org/all/20240926115328.105634-1-puranjay@kernel.org/ - make the cookie u64 instead of int. - re use code from bpf_send_signal_common Changes in v2: v1: https://lore.kernel.org/bpf/20240724113944.75977-1-puranjay@kernel.org/ - Convert to a kfunc - Add mechanism to send a cookie with the signal. ==================== Link: https://lore.kernel.org/r/20241016084136.10305-1-puranjay@kernel.org Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-10-21selftests/bpf: Augment send_signal test with remote signalingPuranjay Mohan
Add testcases to test bpf_send_signal_task(). In these new test cases, the main process triggers the BPF program and the forked process receives the signals. The target process's signal handler receives a cookie from the bpf program. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241016084136.10305-3-puranjay@kernel.org
2024-10-21bpf: Implement bpf_send_signal_task() kfuncPuranjay Mohan
Implement bpf_send_signal_task kfunc that is similar to bpf_send_signal_thread and bpf_send_signal helpers but can be used to send signals to other threads and processes. It also supports sending a cookie with the signal similar to sigqueue(). If the receiving process establishes a handler for the signal using the SA_SIGINFO flag to sigaction(), then it can obtain this cookie via the si_value field of the siginfo_t structure passed as the second argument to the handler. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241016084136.10305-2-puranjay@kernel.org
2024-10-16Merge branch 'bpf-fix-tailcall-infinite-loop-caused-by-freplace'Alexei Starovoitov
Leon Hwang says: ==================== bpf: Fix tailcall infinite loop caused by freplace Previously, I addressed a tailcall infinite loop issue related to trampolines[0]. In this patchset, I resolve a similar issue where a tailcall infinite loop can occur due to the combination of tailcalls and freplace programs. The fix prevents adding extended programs to the prog_array map and blocks the extension of a tail callee program with freplace. Key changes: 1. If a program or its subprogram has been extended by an freplace program, it can no longer be updated to a prog_array map. 2. If a program has been added to a prog_array map, neither it nor its subprograms can be extended by an freplace program. Additionally, an extension program should not be tailcalled. As a result, return -EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a prog_array map. Changes: v7 -> v8: * Address comment from Alexei: * guard(mutex) should not hold range all the way through bpf_arch_text_poke(). * Address suggestion from Xu Kuohai: * Extension prog should not be tailcalled independently. v6 -> v7: * Address comments from Alexei: * Rewrite commit message more imperative and consice with AI. * Extend bpf_trampoline_link_prog() and bpf_trampoline_unlink_prog() to link and unlink target prog for freplace prog. * Use guard(mutex)(&tgt_prog->aux->ext_mutex) instead of mutex_lock()&mutex_unlock() pair. * Address comment from Eduard: * Remove misplaced "Reported-by" and "Closes" tags. v5 -> v6: * Fix a build warning reported by kernel test robot. v4 -> v5: * Move code of linking/unlinking target prog of freplace to trampoline.c. * Address comments from Alexei: * Change type of prog_array_member_cnt to u64. * Combine two patches to one. v3 -> v4: * Address comments from Eduard: * Rename 'tail_callee_cnt' to 'prog_array_member_cnt'. * Add comment to 'prog_array_member_cnt'. * Use a mutex to protect 'is_extended' and 'prog_array_member_cnt'. v2 -> v3: * Address comments from Alexei: * Stop hacking JIT. * Prevent the specific use case at attach/update time. v1 -> v2: * Address comment from Eduard: * Explain why nop5 and xor/nop3 are swapped at prologue. * Address comment from Alexei: * Disallow attaching tail_call_reachable freplace prog to not-tail_call_reachable target in verifier. * Update "bpf, arm64: Fix tailcall infinite loop caused by freplace" with latest arm64 JIT code. Links: [0] https://lore.kernel.org/bpf/20230912150442.2009-1-hffilwlqm@gmail.com/ ==================== Link: https://lore.kernel.org/r/20241015150207.70264-1-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16selftests/bpf: Add tests for bpf_task_from_vpid() kfuncJuntong Deng
This patch adds test cases for bpf_task_from_vpid() kfunc. task_kfunc_from_vpid_no_null_check is used to test the case where the return value is not checked for NULL pointer. test_task_from_vpid_current is used to test obtaining the struct task_struct of the process in the pid namespace based on vpid. test_task_from_vpid_invalid is used to test the case of invalid vpid. test_task_from_vpid_current and test_task_from_vpid_invalid will run in the new namespace. Signed-off-by: Juntong Deng <juntong.deng@outlook.com> Link: https://lore.kernel.org/r/AM6PR03MB5848F13435CD650AC4B7BD7099442@AM6PR03MB5848.eurprd03.prod.outlook.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16selftests/bpf: Add test to verify tailcall and freplace restrictionsLeon Hwang
Add a test case to ensure that attaching a tail callee program with an freplace program fails, and that updating an extended program to a prog_array map is also prohibited. This test is designed to prevent the potential infinite loop issue caused by the combination of tail calls and freplace, ensuring the correct behavior and stability of the system. Additionally, fix the broken tailcalls/tailcall_freplace selftest because an extension prog should not be tailcalled. cd tools/testing/selftests/bpf; ./test_progs -t tailcalls 337/25 tailcalls/tailcall_freplace:OK 337/26 tailcalls/tailcall_bpf2bpf_freplace:OK 337 tailcalls:OK Summary: 1/26 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20241015150207.70264-3-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16bpf: Add bpf_task_from_vpid() kfuncJuntong Deng
bpf_task_from_pid() that currently exists looks up the struct task_struct corresponding to the pid in the root pid namespace (init_pid_ns). This patch adds bpf_task_from_vpid() which looks up the struct task_struct corresponding to vpid in the pid namespace of the current process. This is useful for getting information about other processes in the same pid namespace. Signed-off-by: Juntong Deng <juntong.deng@outlook.com> Link: https://lore.kernel.org/r/AM6PR03MB5848E50DA58F79CDE65433C399442@AM6PR03MB5848.eurprd03.prod.outlook.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16bpf: Prevent tailcall infinite loop caused by freplaceLeon Hwang
There is a potential infinite loop issue that can occur when using a combination of tail calls and freplace. In an upcoming selftest, the attach target for entry_freplace of tailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in entry_freplace leads to entry_tc. This results in an infinite loop: entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc. The problem arises because the tail_call_cnt in entry_freplace resets to zero each time entry_freplace is executed, causing the tail call mechanism to never terminate, eventually leading to a kernel panic. To fix this issue, the solution is twofold: 1. Prevent updating a program extended by an freplace program to a prog_array map. 2. Prevent extending a program that is already part of a prog_array map with an freplace program. This ensures that: * If a program or its subprogram has been extended by an freplace program, it can no longer be updated to a prog_array map. * If a program has been added to a prog_array map, neither it nor its subprograms can be extended by an freplace program. Moreover, an extension program should not be tailcalled. As such, return -EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a prog_array map. Additionally, fix a minor code style issue by replacing eight spaces with a tab for proper formatting. Reviewed-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20241015150207.70264-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16Merge branch 'bpf-add-kmem_cache-iterator-and-kfunc'Alexei Starovoitov
Namhyung Kim says: ==================== bpf: Add kmem_cache iterator and kfunc Hello, I'm proposing a new iterator and a kfunc for the slab memory allocator to get information of each kmem_cache like in /proc/slabinfo or /sys/kernel/slab in more flexible way. v5 changes * set PTR_UNTRUSTED for return value of bpf_get_kmem_cache() (Alexei) * add KF_RCU_PROTECTED to bpf_get_kmem_cache(). See below. (Song) * add WARN_ON_ONCE and comment in kmem_cache_iter_seq_next() (Song) * change kmem_cache_iter_seq functions not to call BPF on intermediate stop * add a subtest to compare the kmem cache info with /proc/slabinfo (Alexei) v4: https://lore.kernel.org/lkml/20241002180956.1781008-1-namhyung@kernel.org * skip kmem_cache_destroy() in kmem_cache_iter_seq_stop() if possible (Vlastimil) * fix a bug in the kmem_cache_iter_seq_start() for the last entry v3: https://lore.kernel.org/lkml/20241002065456.1580143-1-namhyung@kernel.org/ * rework kmem_cache_iter not to hold slab_mutex when running BPF (Alexei) * add virt_addr_valid() check (Alexei) * fix random test failure by running test with the current task (Hyeonggon) v2: https://lore.kernel.org/lkml/20240927184133.968283-1-namhyung@kernel.org/ * rename it to "kmem_cache_iter" * fix a build issue * add Acked-by's from Roman and Vlastimil (Thanks!) * add error codes in the test for debugging v1: https://lore.kernel.org/lkml/20240925223023.735947-1-namhyung@kernel.org/ My use case is `perf lock contention` tool which shows contended locks but many of them are not global locks and don't have symbols. If it can tranlate the address of the lock in a slab object to the name of the slab, it'd be much more useful. I'm not aware of type information in slab yet, but I was told there's a work to associate BTF ID with it. It'd be definitely helpful to my use case. Probably we need another kfunc to get the start address of the object or the offset in the object from an address if the type info is available. But I want to start with a simple thing first. The kmem_cache_iter iterates kmem_cache objects under slab_mutex and will be useful for userspace to prepare some work for specific slabs like setting up filters in advance. And the bpf_get_kmem_cache() kfunc will return a pointer to a slab from the address of a lock. And the test code is to read from the iterator and make sure it finds a slab cache of the task_struct for the current task. The code is available at 'bpf/slab-iter-v5' branch in https://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Thanks, Namhyung ==================== Link: https://lore.kernel.org/r/20241010232505.1339892-1-namhyung@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16selftests/bpf: Add a test for kmem_cache_iterNamhyung Kim
The test traverses all slab caches using the kmem_cache_iter and save the data into slab_result array map. And check if current task's pointer is from "task_struct" slab cache using bpf_get_kmem_cache(). Also compare the result array with /proc/slabinfo if available (when CONFIG_SLUB_DEBUG is on). Note that many of the fields in the slabinfo are transient, so it only compares the name and objsize fields. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20241010232505.1339892-4-namhyung@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16mm/bpf: Add bpf_get_kmem_cache() kfuncNamhyung Kim
The bpf_get_kmem_cache() is to get a slab cache information from a virtual address like virt_to_cache(). If the address is a pointer to a slab object, it'd return a valid kmem_cache pointer, otherwise NULL is returned. It doesn't grab a reference count of the kmem_cache so the caller is responsible to manage the access. The returned point is marked as PTR_UNTRUSTED. The intended use case for now is to symbolize locks in slab objects from the lock contention tracepoints. Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> (mm/*) Acked-by: Vlastimil Babka <vbabka@suse.cz> #mm/slab Signed-off-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20241010232505.1339892-3-namhyung@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-14bpf: Add kmem_cache iteratorNamhyung Kim
The new "kmem_cache" iterator will traverse the list of slab caches and call attached BPF programs for each entry. It should check the argument (ctx.s) if it's NULL before using it. Now the iteration grabs the slab_mutex only if it traverse the list and releases the mutex when it runs the BPF program. The kmem_cache entry is protected by a refcount during the execution. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> #slab Link: https://lore.kernel.org/r/20241010232505.1339892-2-namhyung@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11libbpf: Fix possible compiler warnings in hashmapNamhyung Kim
The hashmap__for_each_entry[_safe] is accessing 'map' as a pointer. But it does without parentheses so passing a static hash map with an ampersand (like '&slab_hash') will cause compiler warnings due to unmatched types as '->' operator has a higher precedence. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241011170021.1490836-1-namhyung@kernel.org
2024-10-11selftests/bpf: Check for timeout in perf_link testIhor Solodrai
Recently perf_link test started unreliably failing on libbpf CI: * https://github.com/libbpf/libbpf/actions/runs/11260672407/job/31312405473 * https://github.com/libbpf/libbpf/actions/runs/11260992334/job/31315514626 * https://github.com/libbpf/libbpf/actions/runs/11263162459/job/31320458251 Part of the test is running a dummy loop for a while and then checking for a counter incremented by the test program. Instead of waiting for an arbitrary number of loop iterations once, check for the test counter in a loop and use get_time_ns() helper to enforce a 100ms timeout. v1: https://lore.kernel.org/bpf/zuRd072x9tumn2iN4wDNs5av0nu5nekMNV4PkR-YwCT10eFFTrUtZBRkLWFbrcCe7guvLStGQlhibo8qWojCO7i2-NGajes5GYIyynexD-w=@pm.me/ Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241011153104.249800-1-ihor.solodrai@pm.me
2024-10-11selftests/bpf: add subprog to BPF object file with no entry programsAndrii Nakryiko
Add a subprogram to BPF object file that otherwise has no entry BPF programs to validate that libbpf can still load this correctly. Until this was fixed, user could expect this very confusing error message: libbpf: prog 'dangling_subprog': missing BPF prog type, check ELF section name '.text' libbpf: prog 'dangling_subprog': failed to load: -22 libbpf: failed to load object 'struct_ops_detach' libbpf: failed to load BPF skeleton 'struct_ops_detach': -22 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241010211731.4121837-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11libbpf: never interpret subprogs in .text as entry programsAndrii Nakryiko
Libbpf pre-1.0 had a legacy logic of allowing singular non-annotated (i.e., not having explicit SEC() annotation) function to be treated as sole entry BPF program (unless there were other explicit entry programs). This behavior was dropped during libbpf 1.0 transition period (unless LIBBPF_STRICT_SEC_NAME flag was unset in libbpf_mode). When 1.0 was released and all the legacy behavior was removed, the bug slipped through leaving this legacy behavior around. Fix this for good, as it actually causes very confusing behavior if BPF object file only has subprograms, but no entry programs. Fixes: bd054102a8c7 ("libbpf: enforce strict libbpf 1.0 behaviors") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241010211731.4121837-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11Merge branch 'selftests-bpf-migrate-and-remove-cgroup-tracing-related-tests'Alexei Starovoitov
Daniel T. Lee says: ==================== selftests/bpf: migrate and remove cgroup/tracing related tests The BPF testing framework has evolved significantly over time. However, some legacy tests in the samples/bpf directory have not kept up with these changes. These outdated tests can cause confusion and increase maintenance efforts. This patchset focuses on migrating outdated cgroup and tracing-related tests from samples/bpf to selftests/bpf, ensuring the BPF test suite remains current and efficient. Tests that are already covered by selftests/bpf are removed, while those not yet covered are migrated. This includes cgroup sock create tests for setting socket attributes and blocking socket creation, as well as the removal of redundant cgroup and tracing tests that have been replaced by newer tests. This patchset covers the following cgroup/tracing tests: - test_overhead: tests the overhead of BPF programs with task_rename, now covered by selftests and benchmark tests (rename-*). [1] - test_override_return: tests the return override functionality, now handled by kprobe_multi_override in selftests. - test_probe_write_user: tests the probe_write_user functionality, now replaced by the probe_user test in selftests. - test_cgrp2_sock: tests cgroup BPF's ability to set sk_bound_dev_if, mark, and priority during socket creation. Migrated to selftests as 'sock_create' since no existing tests fully cover this. - test_cgrp2_sock2: tests blocking socket creation for specific types (AF_INET{6}, SOCK_DGRAM, IPPROTO_ICMP{V6}). Migrated to selftests in 'sock_create' test for coverage. - test_current_task_under_cgroup: tests bpf_current_task_under_cgroup() to check if a task belongs to a cgroup. Already covered by task_under_cgroup at selftest and other cgroup ID tests. - test_cgrp2_tc: tests bpf_skb_under_cgroup() to filter packets based on cgroup. This behavior is now validated by cgroup_skb_sk_lookup, which uses bpf_skb_cgroup_id, making this test redundant. [1]: https://patchwork.kernel.org/cover/13759916 --- Changes in v2: - commit message fix Changes in v3: - Makefile fix ==================== Link: https://lore.kernel.org/r/20241011044847.51584-1-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11samples/bpf: remove obsolete tracing related testsDaniel T. Lee
The samples/bpf has become outdated and often does not follow up with the latest. This commit removes obsolete tracing-related tests. Specifically, 'test_overhead' is duplicate with selftests (and bench), and 'test_override_return', 'test_probe_write_user' tests are obsolete since they have been replaced by kprobe_multi_override and probe_user from selftests respectively. The following files are removed: - test_overhead: tests the overhead of BPF programs with task_rename, now covered by selftests and benchmark tests (rename-*). [1] - test_override_return: tests the return override functionality, now handled by kprobe_multi_override in selftests. - test_probe_write_user: tests the probe_write_user functionality, now replaced by the probe_user test in selftests. This cleanup will help to streamline the testing framework by removing redundant tests. [1]: https://patchwork.kernel.org/cover/13759916 Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20241011044847.51584-5-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11samples/bpf: remove obsolete cgroup related testsDaniel T. Lee
This patch removes the obsolete cgroup related tests. These tests are now redundant because their functionality is already covered by more modern and comprehensive tests under selftests/bpf. The following files are removed: - test_current_task_under_cgroup: tests bpf_current_task_under_cgroup() to check if a task belongs to a cgroup. Already covered by task_under_cgroup at selftest and other cgroup ID tests. - test_cgrp2_tc: tests bpf_skb_under_cgroup() to filter packets based on cgroup. This behavior is now validated by cgroup_skb_sk_lookup, which uses bpf_skb_cgroup_id, making this test redundant. By removing these outdated tests, this patch helps streamline and modernize the test suite, avoiding duplication of test coverage. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20241011044847.51584-4-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11selftests/bpf: migrate cgroup sock create test for prohibiting socketsDaniel T. Lee
This patch continues the migration and removal process for cgroup sock_create tests to selftests. The test being migrated verifies the ability of cgroup BPF to block the creation of specific types of sockets using a verdict. Specifically, the test denies socket creation when the socket is of type AF_INET{6}, SOCK_DGRAM, and IPPROTO_ICMP{V6}. If the requested socket type matches these attributes, the cgroup BPF verdict blocks the socket creation. As with the previous commit, this test currently lacks coverage in selftests, so this patch migrates the functionality into the sock_create tests under selftests. This migration ensures that the socket creation blocking behavior with cgroup bpf program is properly tested within the selftest framework. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20241011044847.51584-3-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11selftests/bpf: migrate cgroup sock create test for setting iface/mark/prioDaniel T. Lee
This patch migrates the old test for cgroup BPF that sets sk_bound_dev_if, mark, and priority when AF_INET{6} sockets are created. The most closely related tests under selftests are 'test_sock' and 'sockopt'. However, these existing tests serve different purposes. 'test_sock' focuses mainly on verifying the socket binding process, while 'sockopt' concentrates on testing the behavior of getsockopt and setsockopt operations for various socket options. Neither of these existing tests directly covers the ability of cgroup BPF to set socket attributes such as sk_bound_dev_if, mark, and priority during socket creation. To address this gap, this patch introduces a migration of the old cgroup socket attribute test, now included as the 'sock_create' test in selftests/bpf. This ensures that the ability to configure these attributes during socket creation is properly tested. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20241011044847.51584-2-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-10selftests/bpf: Removed redundant fd after close in bpf_prog_load_log_bufZhu Jun
Removed unnecessary `fd = -1` assignments after closing file descriptors. because it will be assigned by the function bpf_prog_load().This improves code readability and removes redundant operations. Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241010055737.4292-1-zhujun2@cmss.chinamobile.com
2024-10-10samples/bpf: Fix a resource leakZhu Jun
The opened file should be closed in show_sockopts(), otherwise resource leak will occur that this problem was discovered by reading code Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241010014126.2573-1-zhujun2@cmss.chinamobile.com
2024-10-10bpf: Update bpf_override_return() commentMartin Kelly
The documentation says CONFIG_FUNCTION_ERROR_INJECTION is supported only on x86. This was presumably true at the time of writing, but it's now supported on many other architectures too. Drop this statement, since it's not correct anymore and it fits better in other documentation anyway. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Link: https://lore.kernel.org/r/20241010193301.995909-1-martin.kelly@crowdstrike.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>