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bpf: Add prog flag to struct bpf_ksym object

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Adding 'prog' bool flag to 'struct bpf_ksym' to mark that
this object belongs to bpf_prog object.

This change allows having bpf_prog objects together with
other types (trampolines and dispatchers) in the single
bpf_tree. It's used when searching for bpf_prog exception
tables by the bpf_prog_ksym_find function, where we need
to get the bpf_prog pointer.

>From now we can safely add bpf_ksym support for trampoline
or dispatcher objects, because we can differentiate them
from bpf_prog objects.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-9-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiri Olsa 2020-03-12 20:56:03 +01:00 committed by Alexei Starovoitov
parent eda0c92902
commit cbd76f8d5a
2 changed files with 12 additions and 11 deletions
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1
include/linux/bpf.h
View File

@ -478,6 +478,7 @@ struct bpf_ksym {
char name[KSYM_NAME_LEN];
struct list_head lnode;
struct latch_tree_node tnode;
bool prog;
};
enum bpf_tramp_prog_type {

22
kernel/bpf/core.c
View File

@ -642,6 +642,7 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
bpf_prog_ksym_set_addr(fp);
bpf_prog_ksym_set_name(fp);
fp->aux->ksym.prog = true;
spin_lock_bh(&bpf_lock);
bpf_prog_ksym_node_add(fp->aux);
@ -658,16 +659,6 @@ void bpf_prog_kallsyms_del(struct bpf_prog *fp)
spin_unlock_bh(&bpf_lock);
}
static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
{
struct latch_tree_node *n;
n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
return n ?
container_of(n, struct bpf_prog_aux, ksym.tnode)->prog :
NULL;
}
static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
{
struct latch_tree_node *n;
@ -712,13 +703,22 @@ bool is_bpf_text_address(unsigned long addr)
return ret;
}
static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
{
struct bpf_ksym *ksym = bpf_ksym_find(addr);
return ksym && ksym->prog ?
container_of(ksym, struct bpf_prog_aux, ksym)->prog :
NULL;
}
const struct exception_table_entry *search_bpf_extables(unsigned long addr)
{
const struct exception_table_entry *e = NULL;
struct bpf_prog *prog;
rcu_read_lock();
prog = bpf_prog_kallsyms_find(addr);
prog = bpf_prog_ksym_find(addr);
if (!prog)
goto out;
if (!prog->aux->num_exentries)