bpf: Add name to struct bpf_ksym

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 <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa
2020-03-12 20:55:59 +01:00
committed by Alexei Starovoitov
parent 535911c80a
commit bfea9a8574
4 changed files with 12 additions and 14 deletions

View File

@@ -535,8 +535,10 @@ bpf_prog_ksym_set_addr(struct bpf_prog *prog)
prog->aux->ksym.end = addr + hdr->pages * PAGE_SIZE;
}
void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
static void
bpf_prog_ksym_set_name(struct bpf_prog *prog)
{
char *sym = prog->aux->ksym.name;
const char *end = sym + KSYM_NAME_LEN;
const struct btf_type *type;
const char *func_name;
@@ -643,6 +645,7 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
return;
bpf_prog_ksym_set_addr(fp);
bpf_prog_ksym_set_name(fp);
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
@@ -681,7 +684,7 @@ const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
unsigned long symbol_start = prog->aux->ksym.start;
unsigned long symbol_end = prog->aux->ksym.end;
bpf_get_prog_name(prog, sym);
strncpy(sym, prog->aux->ksym.name, KSYM_NAME_LEN);
ret = sym;
if (size)
@@ -738,7 +741,7 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
if (it++ != symnum)
continue;
bpf_get_prog_name(aux->prog, sym);
strncpy(sym, aux->ksym.name, KSYM_NAME_LEN);
*value = (unsigned long)aux->prog->bpf_func;
*type = BPF_SYM_ELF_TYPE;