linux/kernel/bpf/core.c, branch v5.7

bpf: Enable bpf cgroup hooks to retrieve cgroup v2 and ancestor id

2020-03-28T02:40:39Z

Enable the bpf_get_current_cgroup_id() helper for connect(), sendmsg(), recvmsg() and bind-related hooks in order to retrieve the cgroup v2 context which can then be used as part of the key for BPF map lookups, for example. Given these hooks operate in process context 'current' is always valid and pointing to the app that is performing mentioned syscalls if it's subject to a v2 cgroup. Also with same motivation of commit 7723628101aa ("bpf: Introduce bpf_skb_ancestor_cgroup_id helper") enable retrieval of ancestor from current so the cgroup id can be used for policy lookups which can then forbid connect() / bind(), for example. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/d2a7ef42530ad299e3cbb245e6c12374b72145ef.1585323121.git.daniel@iogearbox.net

bpf: Add bpf_ksym_add/del functions

2020-03-13T19:49:52Z

Separating /proc/kallsyms add/del code and adding bpf_ksym_add/del functions for that. Moving bpf_prog_ksym_node_add/del functions to __bpf_ksym_add/del and changing their argument to 'struct bpf_ksym' object. This way we can call them for other bpf objects types like trampoline and dispatcher. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200312195610.346362-10-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add prog flag to struct bpf_ksym object

2020-03-13T19:49:52Z

Adding 'prog' bool flag to 'struct bpf_ksym' to mark that this object belongs to bpf_prog object. This change allows having bpf_prog objects together with other types (trampolines and dispatchers) in the single bpf_tree. It's used when searching for bpf_prog exception tables by the bpf_prog_ksym_find function, where we need to get the bpf_prog pointer. >From now we can safely add bpf_ksym support for trampoline or dispatcher objects, because we can differentiate them from bpf_prog objects. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200312195610.346362-9-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add bpf_ksym_find function

2020-03-13T19:49:51Z

Adding bpf_ksym_find function that is used bpf bpf address lookup functions: __bpf_address_lookup is_bpf_text_address while keeping bpf_prog_kallsyms_find to be used only for lookup of bpf_prog objects (will happen in following changes). Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200312195610.346362-8-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Move ksym_tnode to bpf_ksym

2020-03-13T19:49:51Z

Moving ksym_tnode list node to 'struct bpf_ksym' object, so the symbol itself can be chained and used in other objects like bpf_trampoline and bpf_dispatcher. We need bpf_ksym object to be linked both in bpf_kallsyms via lnode for /proc/kallsyms and in bpf_tree via tnode for bpf address lookup functions like __bpf_address_lookup or bpf_prog_kallsyms_find. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200312195610.346362-7-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Move lnode list node to struct bpf_ksym

2020-03-13T19:49:51Z

Adding lnode list node to 'struct bpf_ksym' object, so the struct bpf_ksym itself can be chained and used in other objects like bpf_trampoline and bpf_dispatcher. Changing iterator to bpf_ksym in bpf_get_kallsym function. The ksym->start is holding the prog->bpf_func value, so it's ok to use it as value in bpf_get_kallsym. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200312195610.346362-6-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add name to struct bpf_ksym

2020-03-13T19:49:51Z

Adding name to 'struct bpf_ksym' object to carry the name of the symbol for bpf_prog, bpf_trampoline, bpf_dispatcher objects. The current benefit is that name is now generated only when the symbol is added to the list, so we don't need to generate it every time it's accessed. The future benefit is that we will have all the bpf objects symbols represented by struct bpf_ksym. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200312195610.346362-5-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add struct bpf_ksym

2020-03-13T19:49:51Z

Adding 'struct bpf_ksym' object that will carry the kallsym information for bpf symbol. Adding the start and end address to begin with. It will be used by bpf_prog, bpf_trampoline, bpf_dispatcher objects. The symbol_start/symbol_end values were originally used to sort bpf_prog objects. For the address displayed in /proc/kallsyms we are using prog->bpf_func value. I'm using the bpf_func value for program symbol start instead of the symbol_start, because it makes no difference for sorting bpf_prog objects and we can use it directly as an address to display it in /proc/kallsyms. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200312195610.346362-4-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Added new helper bpf_get_ns_current_pid_tgid

2020-03-13T00:33:11Z

New bpf helper bpf_get_ns_current_pid_tgid, This helper will return pid and tgid from current task which namespace matches dev_t and inode number provided, this will allows us to instrument a process inside a container. Signed-off-by: Carlos Neira Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200304204157.58695-3-cneirabustos@gmail.com

bpf: Add BPF_FUNC_jiffies64

2020-01-23T00:30:10Z

This patch adds a helper to read the 64bit jiffies. It will be used in a later patch to implement the bpf_cubic.c. The helper is inlined for jit_requested and 64 BITS_PER_LONG as the map_gen_lookup(). Other cases could be considered together with map_gen_lookup() if needed. Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200122233646.903260-1-kafai@fb.com