From cbd76f8d5ac9c4e99c4ffe5e39a1e907cdf5a76f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Thu, 12 Mar 2020 20:56:03 +0100 Subject: [PATCH] bpf: Add prog flag to struct bpf_ksym object 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 Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200312195610.346362-9-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 + kernel/bpf/core.c | 22 +++++++++++----------- 2 files changed, 12 insertions(+), 11 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 68d66b0..a0cef66 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -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 { diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index cd380f7..7516cbc 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -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) -- 2.7.4