On Tue, Feb 8, 2022 at 11:13 AM Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
>
> From: Alexei Starovoitov <ast@xxxxxxxxxx>
>
> Light skeleton and skel_internal.h have changed.
> Update iterators.lskel.h.
>
> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> ---
> .../bpf/preload/iterators/iterators.lskel.h | 28 +++++++------------
> 1 file changed, 10 insertions(+), 18 deletions(-)
>
> diff --git a/kernel/bpf/preload/iterators/iterators.lskel.h b/kernel/bpf/preload/iterators/iterators.lskel.h
> index d90562d672d2..3e45237f59f4 100644
> --- a/kernel/bpf/preload/iterators/iterators.lskel.h
> +++ b/kernel/bpf/preload/iterators/iterators.lskel.h
> @@ -3,8 +3,6 @@
> #ifndef __ITERATORS_BPF_SKEL_H__
> #define __ITERATORS_BPF_SKEL_H__
>
> -#include <stdlib.h>
> -#include <bpf/bpf.h>
> #include <bpf/skel_internal.h>
>
> struct iterators_bpf {
> @@ -70,31 +68,25 @@ iterators_bpf__destroy(struct iterators_bpf *skel)
> iterators_bpf__detach(skel);
> skel_closenz(skel->progs.dump_bpf_map.prog_fd);
> skel_closenz(skel->progs.dump_bpf_prog.prog_fd);
> - munmap(skel->rodata, 4096);
> + skel_free_map_data(skel->rodata, skel->maps.rodata.initial_value, 4096);
> skel_closenz(skel->maps.rodata.map_fd);
> - free(skel);
> + skel_free(skel);
> }
> static inline struct iterators_bpf *
> iterators_bpf__open(void)
> {
> struct iterators_bpf *skel;
>
> - skel = calloc(sizeof(*skel), 1);
> + skel = skel_alloc(sizeof(*skel));
> if (!skel)
> goto cleanup;
> skel->ctx.sz = (void *)&skel->links - (void *)skel;
> - skel->rodata =
> - mmap(NULL, 4096, PROT_READ | PROT_WRITE,
> - MAP_SHARED | MAP_ANONYMOUS, -1, 0);
> - if (skel->rodata == (void *) -1)
> - goto cleanup;
previously if mmap() failed you'd go to cleanup, but now skel->rodata
will remain NULL. Are you concerned about this?
> - memcpy(skel->rodata, (void *)"\
> + skel->rodata = skel_prep_map_data((void *)"\
> \x20\x20\x69\x64\x20\x6e\x61\x6d\x65\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\
> \x20\x20\x20\x6d\x61\x78\x5f\x65\x6e\x74\x72\x69\x65\x73\x0a\0\x25\x34\x75\x20\
> \x25\x2d\x31\x36\x73\x25\x36\x64\x0a\0\x20\x20\x69\x64\x20\x6e\x61\x6d\x65\x20\
> \x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x61\x74\x74\x61\x63\x68\x65\
> -\x64\x0a\0\x25\x34\x75\x20\x25\x2d\x31\x36\x73\x20\x25\x73\x20\x25\x73\x0a\0", 98);
> - skel->maps.rodata.initial_value = (__u64)(long)skel->rodata;
> +\x64\x0a\0\x25\x34\x75\x20\x25\x2d\x31\x36\x73\x20\x25\x73\x20\x25\x73\x0a\0", 4096, 98);
> return skel;
> cleanup:
> iterators_bpf__destroy(skel);
> @@ -343,11 +335,11 @@ iterators_bpf__load(struct iterators_bpf *skel)
> \0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\x30\x0e\0\0\xb7\x03\0\0\x1c\0\0\0\x85\0\0\0\
> \xa6\0\0\0\xbf\x07\0\0\0\0\0\0\xc5\x07\xd4\xff\0\0\0\0\x63\x7a\x78\xff\0\0\0\0\
> \x61\xa0\x78\xff\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x80\x0e\0\0\x63\x01\0\0\0\
> -\0\0\0\x61\x60\x20\0\0\0\0\0\x15\0\x03\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\
> +\0\0\0\x61\x60\x1c\0\0\0\0\0\x15\0\x03\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\
> \x5c\x0e\0\0\x63\x01\0\0\0\0\0\0\xb7\x01\0\0\0\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\
> \0\x50\x0e\0\0\xb7\x03\0\0\x48\0\0\0\x85\0\0\0\xa6\0\0\0\xbf\x07\0\0\0\0\0\0\
> \xc5\x07\xc3\xff\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x63\x71\0\0\0\0\0\
> -\0\x79\x63\x18\0\0\0\0\0\x15\x03\x04\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x98\
> +\0\x79\x63\x20\0\0\0\0\0\x15\x03\x04\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x98\
> \x0e\0\0\xb7\x02\0\0\x62\0\0\0\x85\0\0\0\x94\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\
> \0\0\0\0\x61\x20\0\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x08\x0f\0\0\x63\x01\0\
> \0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\0\x0f\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\
> @@ -401,12 +393,12 @@ iterators_bpf__load(struct iterators_bpf *skel)
> \x28\0\0\0\0\0\x61\xa0\x84\xff\0\0\0\0\x63\x06\x2c\0\0\0\0\0\x18\x61\0\0\0\0\0\
> \0\0\0\0\0\0\0\0\0\x61\x10\0\0\0\0\0\0\x63\x06\x18\0\0\0\0\0\xb7\0\0\0\0\0\0\0\
> \x95\0\0\0\0\0\0\0";
> + skel->maps.rodata.initial_value = skel_prep_init_value((void **)&skel->rodata, 4096, 98);
> err = bpf_load_and_run(&opts);
> if (err < 0)
> return err;
> - skel->rodata =
> - mmap(skel->rodata, 4096, PROT_READ, MAP_SHARED | MAP_FIXED,
> - skel->maps.rodata.map_fd, 0);
> + skel->rodata = skel_finalize_map_data(&skel->maps.rodata.initial_value,
> + 4096, PROT_READ, skel->maps.rodata.map_fd);
here seems like both before and now, on error, nothing happens. For
kernel mode it matches skeleton behavior (rodata will be NULL), but
for user-space code you'll have (void *)-1, which is probably not
great.
> return 0;
> }
>
> --
> 2.30.2
>
