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From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>
Cc: "Song Liu" <songliubraving@fb.com>,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	"Andrii Nakryiko" <andriin@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"David Miller" <davem@redhat.com>,
	"Björn Töpel" <bjorn.topel@intel.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Jesper Dangaard Brouer" <hawk@kernel.org>,
	"Arnaldo Carvalho de Melo" <acme@redhat.com>,
	"Song Liu" <song@kernel.org>
Subject: [PATCH 05/15] bpf: Move lnode list node to struct bpf_ksym
Date: Mon,  2 Mar 2020 15:31:44 +0100	[thread overview]
Message-ID: <20200302143154.258569-6-jolsa@kernel.org> (raw)
In-Reply-To: <20200302143154.258569-1-jolsa@kernel.org>

Adding lnode list node to 'struct bpf_ksym' object,
so the symbol itself can be chained and used in other
objects like bpf_trampoline and bpf_dispatcher.

Changing iterator to bpf_ksym in bpf_get_kallsym.

The ksym->start is holding the prog->bpf_func value,
so it's ok to use it in bpf_get_kallsym.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 include/linux/bpf.h |  2 +-
 kernel/bpf/core.c   | 22 +++++++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e7b2e9fc256c..f1174d24c185 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -467,6 +467,7 @@ struct bpf_ksym {
 	unsigned long		 start;
 	unsigned long		 end;
 	char			 name[KSYM_NAME_LEN];
+	struct list_head	 lnode;
 };
 
 enum bpf_tramp_prog_type {
@@ -649,7 +650,6 @@ struct bpf_prog_aux {
 	struct bpf_jit_poke_descriptor *poke_tab;
 	u32 size_poke_tab;
 	struct latch_tree_node ksym_tnode;
-	struct list_head ksym_lnode;
 	struct bpf_ksym ksym;
 	const struct bpf_prog_ops *ops;
 	struct bpf_map **used_maps;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index f86cb15d6f2e..084abfbc3362 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -97,7 +97,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
 	fp->aux->prog = fp;
 	fp->jit_requested = ebpf_jit_enabled();
 
-	INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
+	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
 
 	return fp;
 }
@@ -613,18 +613,18 @@ static struct latch_tree_root bpf_tree __cacheline_aligned;
 
 static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
 {
-	WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
-	list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
+	WARN_ON_ONCE(!list_empty(&aux->ksym.lnode));
+	list_add_tail_rcu(&aux->ksym.lnode, &bpf_kallsyms);
 	latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
 }
 
 static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
 {
-	if (list_empty(&aux->ksym_lnode))
+	if (list_empty(&aux->ksym.lnode))
 		return;
 
 	latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
-	list_del_rcu(&aux->ksym_lnode);
+	list_del_rcu(&aux->ksym.lnode);
 }
 
 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
@@ -634,8 +634,8 @@ static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
 
 static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
 {
-	return list_empty(&fp->aux->ksym_lnode) ||
-	       fp->aux->ksym_lnode.prev == LIST_POISON2;
+	return list_empty(&fp->aux->ksym.lnode) ||
+	       fp->aux->ksym.lnode.prev == LIST_POISON2;
 }
 
 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
@@ -729,7 +729,7 @@ const struct exception_table_entry *search_bpf_extables(unsigned long addr)
 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 		    char *sym)
 {
-	struct bpf_prog_aux *aux;
+	struct bpf_ksym *ksym;
 	unsigned int it = 0;
 	int ret = -ERANGE;
 
@@ -737,13 +737,13 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 		return ret;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
+	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
 		if (it++ != symnum)
 			continue;
 
-		strncpy(sym, aux->ksym.name, KSYM_NAME_LEN);
+		strncpy(sym, ksym->name, KSYM_NAME_LEN);
 
-		*value = (unsigned long)aux->prog->bpf_func;
+		*value = ksym->start;
 		*type  = BPF_SYM_ELF_TYPE;
 
 		ret = 0;
-- 
2.24.1


  parent reply	other threads:[~2020-03-02 14:32 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-02 14:31 [PATCHv4 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-03-02 14:31 ` [PATCH 01/15] x86/mm: Rename is_kernel_text to __is_kernel_text Jiri Olsa
2020-03-02 14:31 ` [PATCH 02/15] bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER Jiri Olsa
2020-03-02 14:31 ` [PATCH 03/15] bpf: Add struct bpf_ksym Jiri Olsa
2020-03-02 14:31 ` [PATCH 04/15] bpf: Add name to " Jiri Olsa
2020-03-02 14:31 ` Jiri Olsa [this message]
2020-03-02 14:31 ` [PATCH 06/15] bpf: Add bpf_ksym_tree tree Jiri Olsa
2020-03-03 18:03   ` Alexei Starovoitov
2020-03-03 20:12     ` Jiri Olsa
2020-03-02 14:31 ` [PATCH 07/15] bpf: Move bpf_tree add/del from bpf_prog_ksym_node_add/del Jiri Olsa
2020-03-02 14:31 ` [PATCH 08/15] bpf: Separate kallsyms add/del functions Jiri Olsa
2020-03-02 14:31 ` [PATCH 09/15] bpf: Add bpf_ksym_add/del functions Jiri Olsa
2020-03-02 14:31 ` [PATCH 10/15] bpf: Rename bpf_tree to bpf_progs_tree Jiri Olsa
2020-03-02 14:31 ` [PATCH 11/15] bpf: Add trampolines to kallsyms Jiri Olsa
2020-03-02 14:31 ` [PATCH 12/15] bpf: Add dispatchers " Jiri Olsa
2020-03-02 14:31 ` [PATCH 13/15] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event Jiri Olsa
2020-03-02 14:31 ` [PATCH 14/15] perf tools: Set ksymbol dso as loaded on arrival Jiri Olsa
2020-03-02 14:31 ` [PATCH 15/15] perf annotate: Add base support for bpf_image Jiri Olsa
2020-03-12 19:55 [PATCHv5 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-03-12 19:56 ` [PATCH 05/15] bpf: Move lnode list node to struct bpf_ksym Jiri Olsa

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