We are going to remove "ftrace_ops->private == bpf_trampoline" setup
in following changes.
Adding ip argument to ftrace_ops_func_t callback function, so we can
use it to look up the trampoline.
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
include/linux/ftrace.h | 2 +-
kernel/bpf/trampoline.c | 26 ++++++++++++++++++++++++--
kernel/trace/ftrace.c | 6 +++---
3 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 85f4ab1a1e72..1a61f969550d 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -394,7 +394,7 @@ enum ftrace_ops_cmd {
* Negative on failure. The return value is dependent on the
* callback.
*/
-typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd
cmd);
+typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, unsigned long ip, enum
ftrace_ops_cmd cmd);
#ifdef CONFIG_DYNAMIC_FTRACE
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 84bcd9f6bd74..398c1a722d83 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -33,11 +33,33 @@ static DEFINE_MUTEX(trampoline_mutex);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
static int bpf_trampoline_update(struct bpf_trampoline *tr, bool
lock_direct_mutex);
-static int bpf_tramp_ftrace_ops_func(struct ftrace_ops *ops, enum
ftrace_ops_cmd cmd)
+static struct bpf_trampoline *bpf_trampoline_ip_lookup(unsigned long ip)
{
- struct bpf_trampoline *tr = ops->private;
+ struct hlist_head *head_ip;
+ struct bpf_trampoline *tr;
+
+ mutex_lock(&trampoline_mutex);
+ head_ip = &trampoline_ip_table[hash_64(ip, TRAMPOLINE_HASH_BITS)];
+ hlist_for_each_entry(tr, head_ip, hlist_ip) {
+ if (tr->func.addr == (void *) ip)
+ goto out;
+ }
+ tr = NULL;
+out:
+ mutex_unlock(&trampoline_mutex);
+ return tr;
+}
+
+static int bpf_tramp_ftrace_ops_func(struct ftrace_ops *ops, unsigned long ip,
+ enum ftrace_ops_cmd cmd)
+{
+ struct bpf_trampoline *tr;
int ret = 0;
+ tr = bpf_trampoline_ip_lookup(ip);
+ if (!tr)
+ return -EINVAL;
+
if (cmd == FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF) {
/* This is called inside register_ftrace_direct_multi(), so
* tr->mutex is already locked.
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 151ca94f496a..943feabdd5e6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2040,7 +2040,7 @@ static int __ftrace_hash_update_ipmodify(struct
ftrace_ops *ops,
*/
if (!ops->ops_func)
return -EBUSY;
- ret = ops->ops_func(ops,
FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF);
+ ret = ops->ops_func(ops, rec->ip,
FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF);
if (ret)
return ret;
} else if (is_ipmodify) {
@@ -8746,7 +8746,7 @@ static int prepare_direct_functions_for_ipmodify(struct
ftrace_ops *ops)
if (!op->ops_func)
return -EBUSY;
- ret = op->ops_func(op,
FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
+ ret = op->ops_func(op, ip,
FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
if (ret)
return ret;
}
@@ -8793,7 +8793,7 @@ static void
cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
/* The cleanup is optional, ignore any errors */
if (found_op && op->ops_func)
- op->ops_func(op,
FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
+ op->ops_func(op, ip,
FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
}
}
mutex_unlock(&direct_mutex);
--
2.50.1
