From bc0b5a03079bd78fb3d5cba1ccabf0a7efb1d99f Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 4 Sep 2020 17:14:54 +0100 Subject: tools, bpf: Synchronise BPF UAPI header with tools Synchronise the bpf.h header under tools, to report the fixes recently brought to the documentation for the BPF helpers. Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200904161454.31135-4-quentin@isovalent.com --- tools/include/uapi/linux/bpf.h | 87 ++++++++++++++++++++++-------------------- 1 file changed, 45 insertions(+), 42 deletions(-) (limited to 'tools/include') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 8dda13880957..90359cab501d 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3349,38 +3349,38 @@ union bpf_attr { * Description * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer. * Return - * *sk* if casting is valid, or NULL otherwise. + * *sk* if casting is valid, or **NULL** otherwise. * * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk) * Description * Dynamically cast a *sk* pointer to a *tcp_sock* pointer. * Return - * *sk* if casting is valid, or NULL otherwise. + * *sk* if casting is valid, or **NULL** otherwise. * * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk) * Description * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer. * Return - * *sk* if casting is valid, or NULL otherwise. + * *sk* if casting is valid, or **NULL** otherwise. * * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk) * Description * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. * Return - * *sk* if casting is valid, or NULL otherwise. + * *sk* if casting is valid, or **NULL** otherwise. * * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk) * Description * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. * Return - * *sk* if casting is valid, or NULL otherwise. + * *sk* if casting is valid, or **NULL** otherwise. * * long bpf_get_task_stack(struct task_struct *task, void *buf, u32 size, u64 flags) * Description * Return a user or a kernel stack in bpf program provided buffer. * To achieve this, the helper needs *task*, which is a valid - * pointer to struct task_struct. To store the stacktrace, the - * bpf program provides *buf* with a nonnegative *size*. + * pointer to **struct task_struct**. To store the stacktrace, the + * bpf program provides *buf* with a nonnegative *size*. * * The last argument, *flags*, holds the number of stack frames to * skip (from 0 to 255), masked with @@ -3410,12 +3410,12 @@ union bpf_attr { * long bpf_load_hdr_opt(struct bpf_sock_ops *skops, void *searchby_res, u32 len, u64 flags) * Description * Load header option. Support reading a particular TCP header - * option for bpf program (BPF_PROG_TYPE_SOCK_OPS). + * option for bpf program (**BPF_PROG_TYPE_SOCK_OPS**). * * If *flags* is 0, it will search the option from the - * sock_ops->skb_data. The comment in "struct bpf_sock_ops" + * *skops*\ **->skb_data**. The comment in **struct bpf_sock_ops** * has details on what skb_data contains under different - * sock_ops->op. + * *skops*\ **->op**. * * The first byte of the *searchby_res* specifies the * kind that it wants to search. @@ -3435,7 +3435,7 @@ union bpf_attr { * [ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ]. * * To search for the standard window scale option (3), - * the searchby_res should be [ 3, 0, 0, .... 0 ]. + * the *searchby_res* should be [ 3, 0, 0, .... 0 ]. * Note, kind-length must be 0 for regular option. * * Searching for No-Op (0) and End-of-Option-List (1) are @@ -3445,27 +3445,30 @@ union bpf_attr { * of a header option. * * Supported flags: + * * * **BPF_LOAD_HDR_OPT_TCP_SYN** to search from the * saved_syn packet or the just-received syn packet. * * Return - * >0 when found, the header option is copied to *searchby_res*. - * The return value is the total length copied. + * > 0 when found, the header option is copied to *searchby_res*. + * The return value is the total length copied. On failure, a + * negative error code is returned: * - * **-EINVAL** If param is invalid + * **-EINVAL** if a parameter is invalid. * - * **-ENOMSG** The option is not found + * **-ENOMSG** if the option is not found. * - * **-ENOENT** No syn packet available when - * **BPF_LOAD_HDR_OPT_TCP_SYN** is used + * **-ENOENT** if no syn packet is available when + * **BPF_LOAD_HDR_OPT_TCP_SYN** is used. * - * **-ENOSPC** Not enough space. Only *len* number of - * bytes are copied. + * **-ENOSPC** if there is not enough space. Only *len* number of + * bytes are copied. * - * **-EFAULT** Cannot parse the header options in the packet + * **-EFAULT** on failure to parse the header options in the + * packet. * - * **-EPERM** This helper cannot be used under the - * current sock_ops->op. + * **-EPERM** if the helper cannot be used under the current + * *skops*\ **->op**. * * long bpf_store_hdr_opt(struct bpf_sock_ops *skops, const void *from, u32 len, u64 flags) * Description @@ -3483,44 +3486,44 @@ union bpf_attr { * by searching the same option in the outgoing skb. * * This helper can only be called during - * BPF_SOCK_OPS_WRITE_HDR_OPT_CB. + * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**. * * Return * 0 on success, or negative error in case of failure: * - * **-EINVAL** If param is invalid + * **-EINVAL** If param is invalid. * - * **-ENOSPC** Not enough space in the header. - * Nothing has been written + * **-ENOSPC** if there is not enough space in the header. + * Nothing has been written * - * **-EEXIST** The option has already existed + * **-EEXIST** if the option already exists. * - * **-EFAULT** Cannot parse the existing header options + * **-EFAULT** on failrue to parse the existing header options. * - * **-EPERM** This helper cannot be used under the - * current sock_ops->op. + * **-EPERM** if the helper cannot be used under the current + * *skops*\ **->op**. * * long bpf_reserve_hdr_opt(struct bpf_sock_ops *skops, u32 len, u64 flags) * Description * Reserve *len* bytes for the bpf header option. The - * space will be used by bpf_store_hdr_opt() later in - * BPF_SOCK_OPS_WRITE_HDR_OPT_CB. + * space will be used by **bpf_store_hdr_opt**\ () later in + * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**. * - * If bpf_reserve_hdr_opt() is called multiple times, + * If **bpf_reserve_hdr_opt**\ () is called multiple times, * the total number of bytes will be reserved. * * This helper can only be called during - * BPF_SOCK_OPS_HDR_OPT_LEN_CB. + * **BPF_SOCK_OPS_HDR_OPT_LEN_CB**. * * Return * 0 on success, or negative error in case of failure: * - * **-EINVAL** if param is invalid + * **-EINVAL** if a parameter is invalid. * - * **-ENOSPC** Not enough space in the header. + * **-ENOSPC** if there is not enough space in the header. * - * **-EPERM** This helper cannot be used under the - * current sock_ops->op. + * **-EPERM** if the helper cannot be used under the current + * *skops*\ **->op**. * * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags) * Description @@ -3560,9 +3563,9 @@ union bpf_attr { * * long bpf_d_path(struct path *path, char *buf, u32 sz) * Description - * Return full path for given 'struct path' object, which - * needs to be the kernel BTF 'path' object. The path is - * returned in the provided buffer 'buf' of size 'sz' and + * Return full path for given **struct path** object, which + * needs to be the kernel BTF *path* object. The path is + * returned in the provided buffer *buf* of size *sz* and * is zero terminated. * * Return @@ -3573,7 +3576,7 @@ union bpf_attr { * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr) * Description * Read *size* bytes from user space address *user_ptr* and store - * the data in *dst*. This is a wrapper of copy_from_user(). + * the data in *dst*. This is a wrapper of **copy_from_user**\ (). * Return * 0 on success, or a negative error in case of failure. */ -- cgit v1.2.3 From 1aef5b4391f0c75c0a1523706a7b0311846ee12f Mon Sep 17 00:00:00 2001 From: Song Liu Date: Thu, 10 Sep 2020 13:33:14 -0700 Subject: bpf: Fix comment for helper bpf_current_task_under_cgroup() This should be "current" not "skb". Fixes: c6b5fb8690fa ("bpf: add documentation for eBPF helpers (42-50)") Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Cc: Link: https://lore.kernel.org/bpf/20200910203314.70018-1-songliubraving@fb.com --- include/uapi/linux/bpf.h | 4 ++-- tools/include/uapi/linux/bpf.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/include') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 90359cab501d..7dd314176df7 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1447,8 +1447,8 @@ union bpf_attr { * Return * The return value depends on the result of the test, and can be: * - * * 0, if the *skb* task belongs to the cgroup2. - * * 1, if the *skb* task does not belong to the cgroup2. + * * 0, if current task belongs to the cgroup2. + * * 1, if current task does not belong to the cgroup2. * * A negative error code, if an error occurred. * * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 90359cab501d..7dd314176df7 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1447,8 +1447,8 @@ union bpf_attr { * Return * The return value depends on the result of the test, and can be: * - * * 0, if the *skb* task belongs to the cgroup2. - * * 1, if the *skb* task does not belong to the cgroup2. + * * 0, if current task belongs to the cgroup2. + * * 1, if current task does not belong to the cgroup2. * * A negative error code, if an error occurred. * * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags) -- cgit v1.2.3 From ef15314aa5de955c6afd87d512e8b00f5ac08d06 Mon Sep 17 00:00:00 2001 From: YiFei Zhu Date: Tue, 15 Sep 2020 16:45:40 -0700 Subject: bpf: Add BPF_PROG_BIND_MAP syscall This syscall binds a map to a program. Returns success if the map is already bound to the program. Signed-off-by: YiFei Zhu Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Cc: YiFei Zhu Link: https://lore.kernel.org/bpf/20200915234543.3220146-3-sdf@google.com --- include/uapi/linux/bpf.h | 7 +++++ kernel/bpf/syscall.c | 63 ++++++++++++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++ 3 files changed, 77 insertions(+) (limited to 'tools/include') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7dd314176df7..a22812561064 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -124,6 +124,7 @@ enum bpf_cmd { BPF_ENABLE_STATS, BPF_ITER_CREATE, BPF_LINK_DETACH, + BPF_PROG_BIND_MAP, }; enum bpf_map_type { @@ -658,6 +659,12 @@ union bpf_attr { __u32 flags; } iter_create; + struct { /* struct used by BPF_PROG_BIND_MAP command */ + __u32 prog_fd; + __u32 map_fd; + __u32 flags; /* extra flags */ + } prog_bind_map; + } __attribute__((aligned(8))); /* The description below is an attempt at providing documentation to eBPF diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a67b8c6746be..2ce32cad5c8e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4161,6 +4161,66 @@ static int bpf_iter_create(union bpf_attr *attr) return err; } +#define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags + +static int bpf_prog_bind_map(union bpf_attr *attr) +{ + struct bpf_prog *prog; + struct bpf_map *map; + struct bpf_map **used_maps_old, **used_maps_new; + int i, ret = 0; + + if (CHECK_ATTR(BPF_PROG_BIND_MAP)) + return -EINVAL; + + if (attr->prog_bind_map.flags) + return -EINVAL; + + prog = bpf_prog_get(attr->prog_bind_map.prog_fd); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + map = bpf_map_get(attr->prog_bind_map.map_fd); + if (IS_ERR(map)) { + ret = PTR_ERR(map); + goto out_prog_put; + } + + mutex_lock(&prog->aux->used_maps_mutex); + + used_maps_old = prog->aux->used_maps; + + for (i = 0; i < prog->aux->used_map_cnt; i++) + if (used_maps_old[i] == map) + goto out_unlock; + + used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, + sizeof(used_maps_new[0]), + GFP_KERNEL); + if (!used_maps_new) { + ret = -ENOMEM; + goto out_unlock; + } + + memcpy(used_maps_new, used_maps_old, + sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); + used_maps_new[prog->aux->used_map_cnt] = map; + + prog->aux->used_map_cnt++; + prog->aux->used_maps = used_maps_new; + + kfree(used_maps_old); + +out_unlock: + mutex_unlock(&prog->aux->used_maps_mutex); + + if (ret) + bpf_map_put(map); +out_prog_put: + bpf_prog_put(prog); + return ret; +} + SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) { union bpf_attr attr; @@ -4294,6 +4354,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz case BPF_LINK_DETACH: err = link_detach(&attr); break; + case BPF_PROG_BIND_MAP: + err = bpf_prog_bind_map(&attr); + break; default: err = -EINVAL; break; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 7dd314176df7..a22812561064 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -124,6 +124,7 @@ enum bpf_cmd { BPF_ENABLE_STATS, BPF_ITER_CREATE, BPF_LINK_DETACH, + BPF_PROG_BIND_MAP, }; enum bpf_map_type { @@ -658,6 +659,12 @@ union bpf_attr { __u32 flags; } iter_create; + struct { /* struct used by BPF_PROG_BIND_MAP command */ + __u32 prog_fd; + __u32 map_fd; + __u32 flags; /* extra flags */ + } prog_bind_map; + } __attribute__((aligned(8))); /* The description below is an attempt at providing documentation to eBPF -- cgit v1.2.3 From 27774b7073b5d520c80f1fcb8e9993fc139f21bd Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Mon, 21 Sep 2020 13:12:19 +0100 Subject: btf: Add BTF_ID_LIST_SINGLE macro Add a convenience macro that allows defining a BTF ID list with a single item. This lets us cut down on repetitive macros. Suggested-by: Andrii Nakryiko Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200921121227.255763-4-lmb@cloudflare.com --- include/linux/btf_ids.h | 8 ++++++++ tools/include/linux/btf_ids.h | 8 ++++++++ 2 files changed, 16 insertions(+) (limited to 'tools/include') diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h index 210b086188a3..57890b357f85 100644 --- a/include/linux/btf_ids.h +++ b/include/linux/btf_ids.h @@ -76,6 +76,13 @@ extern u32 name[]; #define BTF_ID_LIST_GLOBAL(name) \ __BTF_ID_LIST(name, globl) +/* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with + * a single entry. + */ +#define BTF_ID_LIST_SINGLE(name, prefix, typename) \ + BTF_ID_LIST(name) \ + BTF_ID(prefix, typename) + /* * The BTF_ID_UNUSED macro defines 4 zero bytes. * It's used when we want to define 'unused' entry @@ -140,6 +147,7 @@ extern struct btf_id_set name; #define BTF_ID(prefix, name) #define BTF_ID_UNUSED #define BTF_ID_LIST_GLOBAL(name) u32 name[1]; +#define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 name[1]; #define BTF_SET_START(name) static struct btf_id_set name = { 0 }; #define BTF_SET_START_GLOBAL(name) static struct btf_id_set name = { 0 }; #define BTF_SET_END(name) diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h index 210b086188a3..57890b357f85 100644 --- a/tools/include/linux/btf_ids.h +++ b/tools/include/linux/btf_ids.h @@ -76,6 +76,13 @@ extern u32 name[]; #define BTF_ID_LIST_GLOBAL(name) \ __BTF_ID_LIST(name, globl) +/* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with + * a single entry. + */ +#define BTF_ID_LIST_SINGLE(name, prefix, typename) \ + BTF_ID_LIST(name) \ + BTF_ID(prefix, typename) + /* * The BTF_ID_UNUSED macro defines 4 zero bytes. * It's used when we want to define 'unused' entry @@ -140,6 +147,7 @@ extern struct btf_id_set name; #define BTF_ID(prefix, name) #define BTF_ID_UNUSED #define BTF_ID_LIST_GLOBAL(name) u32 name[1]; +#define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 name[1]; #define BTF_SET_START(name) static struct btf_id_set name = { 0 }; #define BTF_SET_START_GLOBAL(name) static struct btf_id_set name = { 0 }; #define BTF_SET_END(name) -- cgit v1.2.3