Re: [PATCH] m68k: Wire up bpf

From: Geert Uytterhoeven
Date: Wed Oct 22 2014 - 03:48:39 EST


Hi Alexei,

On Tue, 21 Oct 2014, Alexei Starovoitov wrote:
> On Tue, Oct 21, 2014 at 10:30 AM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
> > Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > ---
> > arch/m68k/include/asm/unistd.h | 2 +-
> > arch/m68k/include/uapi/asm/unistd.h | 1 +
> > arch/m68k/kernel/syscalltable.S | 1 +
> > 3 files changed, 3 insertions(+), 1 deletion(-)
>
> did the tests pass in samples/bpf/test_verifier ?

Thanks for reminding me about the existence of the tests ;-)

Yes, they passed.

Note that gcc 4.1.2 doesn't like C99-initialization of anonymous
struct and union members, so I had to use the patch below:

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d18316f9e9c488b0..6ec5060a6ece8f23 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -123,7 +123,7 @@ union bpf_attr {
__u32 key_size; /* size of key in bytes */
__u32 value_size; /* size of value in bytes */
__u32 max_entries; /* max number of entries in a map */
- };
+ } create;

struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
__u32 map_fd;
@@ -132,7 +132,7 @@ union bpf_attr {
__aligned_u64 value;
__aligned_u64 next_key;
};
- };
+ } elem;

struct { /* anonymous struct used by BPF_PROG_LOAD command */
__u32 prog_type; /* one of enum bpf_prog_type */
@@ -142,7 +142,7 @@ union bpf_attr {
__u32 log_level; /* verbosity level of verifier */
__u32 log_size; /* size of user buffer */
__aligned_u64 log_buf; /* user supplied buffer */
- };
+ } load;
} __attribute__((aligned(8)));

/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c
index ff65044207384b90..bf1d0bae42c7c6aa 100644
--- a/samples/bpf/libbpf.c
+++ b/samples/bpf/libbpf.c
@@ -18,10 +18,10 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries)
{
union bpf_attr attr = {
- .map_type = map_type,
- .key_size = key_size,
- .value_size = value_size,
- .max_entries = max_entries
+ .create.map_type = map_type,
+ .create.key_size = key_size,
+ .create.value_size = value_size,
+ .create.max_entries = max_entries
};

return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
@@ -30,10 +30,10 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int bpf_update_elem(int fd, void *key, void *value)
{
union bpf_attr attr = {
- .map_fd = fd,
- .key = ptr_to_u64(key),
- .value = ptr_to_u64(value),
+ .elem.map_fd = fd,
+ .elem.key = ptr_to_u64(key),
};
+ attr.elem.value = ptr_to_u64(value);

return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}
@@ -41,10 +41,10 @@ int bpf_update_elem(int fd, void *key, void *value)
int bpf_lookup_elem(int fd, void *key, void *value)
{
union bpf_attr attr = {
- .map_fd = fd,
- .key = ptr_to_u64(key),
- .value = ptr_to_u64(value),
+ .elem.map_fd = fd,
+ .elem.key = ptr_to_u64(key),
};
+ attr.elem.value = ptr_to_u64(value);

return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}
@@ -52,8 +52,8 @@ int bpf_lookup_elem(int fd, void *key, void *value)
int bpf_delete_elem(int fd, void *key)
{
union bpf_attr attr = {
- .map_fd = fd,
- .key = ptr_to_u64(key),
+ .elem.map_fd = fd,
+ .elem.key = ptr_to_u64(key),
};

return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
@@ -62,10 +62,10 @@ int bpf_delete_elem(int fd, void *key)
int bpf_get_next_key(int fd, void *key, void *next_key)
{
union bpf_attr attr = {
- .map_fd = fd,
- .key = ptr_to_u64(key),
- .next_key = ptr_to_u64(next_key),
+ .elem.map_fd = fd,
+ .elem.key = ptr_to_u64(key),
};
+ attr.elem.next_key = ptr_to_u64(next_key);

return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
}
@@ -79,13 +79,13 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
const char *license)
{
union bpf_attr attr = {
- .prog_type = prog_type,
- .insns = ptr_to_u64((void *) insns),
- .insn_cnt = prog_len / sizeof(struct bpf_insn),
- .license = ptr_to_u64((void *) license),
- .log_buf = ptr_to_u64(bpf_log_buf),
- .log_size = LOG_BUF_SIZE,
- .log_level = 1,
+ .load.prog_type = prog_type,
+ .load.insns = ptr_to_u64((void *) insns),
+ .load.insn_cnt = prog_len / sizeof(struct bpf_insn),
+ .load.license = ptr_to_u64((void *) license),
+ .load.log_buf = ptr_to_u64(bpf_log_buf),
+ .load.log_size = LOG_BUF_SIZE,
+ .load.log_level = 1,
};

bpf_log_buf[0] = 0;

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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