Re: [PATCH net-next] bpf: Print function name in addition to function id

[David Miller]

From: Thomas Graf 
Date: Thu, 27 Oct 2016 11:23:51 +0200

> The verifier currently prints raw function ids when printing CALL
> instructions or when complaining:
> 
>   5: (85) call 23
>   unknown func 23
> 
> print a meaningful function name instead:
> 
>   5: (85) call bpf_redirect#23
>   unknown func bpf_redirect#23
> 
> Moves the function documentation to a single comment and renames all
> helpers names in the list to conform to the bpf_ prefix notation so
> they can be greped in the kernel source.
> 
> Signed-off-by: Thomas Graf 
> Acked-by: Daniel Borkmann 
> Acked-by: Alexei Starovoitov 

Applied.

[PATCH net-next] bpf: Print function name in addition to function id

[Thomas Graf]

The verifier currently prints raw function ids when printing CALL
instructions or when complaining:

5: (85) call 23
unknown func 23

print a meaningful function name instead:

5: (85) call bpf_redirect#23
unknown func bpf_redirect#23

Moves the function documentation to a single comment and renames all
helpers names in the list to conform to the bpf_ prefix notation so
they can be greped in the kernel source.

Signed-off-by: Thomas Graf 
Acked-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
---
 include/uapi/linux/bpf.h | 574 ---
 kernel/bpf/verifier.c|  35 ++-
 2 files changed, 316 insertions(+), 293 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 374ef58..e2f38e0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -143,297 +143,301 @@ union bpf_attr {
};
 } __attribute__((aligned(8)));
 
+/* BPF helper function descriptions:
+ *
+ * void *bpf_map_lookup_elem(, )
+ * Return: Map value or NULL
+ *
+ * int bpf_map_update_elem(, , , flags)
+ * Return: 0 on success or negative error
+ *
+ * int bpf_map_delete_elem(, )
+ * Return: 0 on success or negative error
+ *
+ * int bpf_probe_read(void *dst, int size, void *src)
+ * Return: 0 on success or negative error
+ *
+ * u64 bpf_ktime_get_ns(void)
+ * Return: current ktime
+ *
+ * int bpf_trace_printk(const char *fmt, int fmt_size, ...)
+ * Return: length of buffer written or negative error
+ *
+ * u32 bpf_prandom_u32(void)
+ * Return: random value
+ *
+ * u32 bpf_raw_smp_processor_id(void)
+ * Return: SMP processor ID
+ *
+ * int bpf_skb_store_bytes(skb, offset, from, len, flags)
+ * store bytes into packet
+ * @skb: pointer to skb
+ * @offset: offset within packet from skb->mac_header
+ * @from: pointer where to copy bytes from
+ * @len: number of bytes to store into packet
+ * @flags: bit 0 - if true, recompute skb->csum
+ * other bits - reserved
+ * Return: 0 on success or negative error
+ *
+ * int bpf_l3_csum_replace(skb, offset, from, to, flags)
+ * recompute IP checksum
+ * @skb: pointer to skb
+ * @offset: offset within packet where IP checksum is located
+ * @from: old value of header field
+ * @to: new value of header field
+ * @flags: bits 0-3 - size of header field
+ * other bits - reserved
+ * Return: 0 on success or negative error
+ *
+ * int bpf_l4_csum_replace(skb, offset, from, to, flags)
+ * recompute TCP/UDP checksum
+ * @skb: pointer to skb
+ * @offset: offset within packet where TCP/UDP checksum is located
+ * @from: old value of header field
+ * @to: new value of header field
+ * @flags: bits 0-3 - size of header field
+ * bit 4 - is pseudo header
+ * other bits - reserved
+ * Return: 0 on success or negative error
+ *
+ * int bpf_tail_call(ctx, prog_array_map, index)
+ * jump into another BPF program
+ * @ctx: context pointer passed to next program
+ * @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
+ * @index: index inside array that selects specific program to run
+ * Return: 0 on success or negative error
+ *
+ * int bpf_clone_redirect(skb, ifindex, flags)
+ * redirect to another netdev
+ * @skb: pointer to skb
+ * @ifindex: ifindex of the net device
+ * @flags: bit 0 - if set, redirect to ingress instead of egress
+ * other bits - reserved
+ * Return: 0 on success or negative error
+ *
+ * u64 bpf_get_current_pid_tgid(void)
+ * Return: current->tgid << 32 | current->pid
+ *
+ * u64 bpf_get_current_uid_gid(void)
+ * Return: current_gid << 32 | current_uid
+ *
+ * int bpf_get_current_comm(char *buf, int size_of_buf)
+ * stores current->comm into buf
+ * Return: 0 on success or negative error
+ *
+ * u32 bpf_get_cgroup_classid(skb)
+ * retrieve a proc's classid
+ * @skb: pointer to skb
+ * Return: classid if != 0
+ *
+ * int bpf_skb_vlan_push(skb, vlan_proto, vlan_tci)
+ * Return: 0 on success or negative error
+ *
+ * int bpf_skb_vlan_pop(skb)
+ * Return: 0 on success or negative error
+ *
+ * int bpf_skb_get_tunnel_key(skb, key, size, flags)
+ * int bpf_skb_set_tunnel_key(skb, key, size, flags)
+ * retrieve or populate tunnel metadata
+ * @skb: pointer to skb
+ * @key: pointer to 'struct bpf_tunnel_key'
+ * @size: size of 'struct bpf_tunnel_key'
+ * @flags: room for future extensions
+ * Return: 0 on success or negative error
+ *
+ * u64 bpf_perf_event_read(, index)
+ * Return: Number events read or error code
+ *
+ * int bpf_redirect(ifindex, flags)
+ * redirect to another netdev
+ * @ifindex: ifindex of the net device
+ * @flags: bit 0 - if set, redirect to ingress instead of egress
+ * other bits - reserved
+ *