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tracing: fprobe: use ftrace if CONFIG_DYNAMIC_FTRACE_WITH_ARGS 

For now, we will use ftrace for the fprobe if fp->exit_handler not exists
and CONFIG_DYNAMIC_FTRACE_WITH_REGS is enabled.

However, CONFIG_DYNAMIC_FTRACE_WITH_REGS is not supported by some arch,
such as arm. What we need in the fprobe is the function arguments, so we
can use ftrace for fprobe if CONFIG_DYNAMIC_FTRACE_WITH_ARGS is enabled.

Therefore, use ftrace if CONFIG_DYNAMIC_FTRACE_WITH_REGS or
CONFIG_DYNAMIC_FTRACE_WITH_ARGS enabled.

Link: https://lore.kernel.org/all/20251103063434.47388-1-dongml2@chinatelecom.cn/

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Menglong Dong 2025-11-03 14:34:34 +08:00 committed by Masami Hiramatsu (Google)
parent 08ed5c81f6
commit cd06078a38
1 changed files with 22 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
kernel/trace/fprobe.c
View File

@ -44,6 +44,7 @@
static struct hlist_head fprobe_table[FPROBE_TABLE_SIZE];
static struct rhltable fprobe_ip_table;
static DEFINE_MUTEX(fprobe_mutex);
static struct fgraph_ops fprobe_graph_ops;
static u32 fprobe_node_hashfn(const void *data, u32 len, u32 seed)
{
@ -254,7 +255,7 @@ static inline int __fprobe_kprobe_handler(unsigned long ip, unsigned long parent
return ret;
}
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
#if defined(CONFIG_DYNAMIC_FTRACE_WITH_ARGS) || defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS)
/* ftrace_ops callback, this processes fprobes which have only entry_handler. */
static void fprobe_ftrace_entry(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
@ -295,7 +296,7 @@ NOKPROBE_SYMBOL(fprobe_ftrace_entry);
static struct ftrace_ops fprobe_ftrace_ops = {
.func = fprobe_ftrace_entry,
.flags = FTRACE_OPS_FL_SAVE_REGS,
.flags = FTRACE_OPS_FL_SAVE_ARGS,
};
static int fprobe_ftrace_active;
@ -335,6 +336,15 @@ static bool fprobe_is_ftrace(struct fprobe *fp)
{
return !fp->exit_handler;
}
#ifdef CONFIG_MODULES
static void fprobe_set_ips(unsigned long *ips, unsigned int cnt, int remove,
int reset)
{
ftrace_set_filter_ips(&fprobe_graph_ops.ops, ips, cnt, remove, reset);
ftrace_set_filter_ips(&fprobe_ftrace_ops, ips, cnt, remove, reset);
}
#endif
#else
static int fprobe_ftrace_add_ips(unsigned long *addrs, int num)
{
@ -349,7 +359,15 @@ static bool fprobe_is_ftrace(struct fprobe *fp)
{
return false;
}
#ifdef CONFIG_MODULES
static void fprobe_set_ips(unsigned long *ips, unsigned int cnt, int remove,
int reset)
{
ftrace_set_filter_ips(&fprobe_graph_ops.ops, ips, cnt, remove, reset);
}
#endif
#endif /* !CONFIG_DYNAMIC_FTRACE_WITH_ARGS && !CONFIG_DYNAMIC_FTRACE_WITH_REGS */
/* fgraph_ops callback, this processes fprobes which have exit_handler. */
static int fprobe_fgraph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
@ -596,14 +614,8 @@ static int fprobe_module_callback(struct notifier_block *nb,
} while (node == ERR_PTR(-EAGAIN));
rhashtable_walk_exit(&iter);
if (alist.index > 0) {
ftrace_set_filter_ips(&fprobe_graph_ops.ops,
alist.addrs, alist.index, 1, 0);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
ftrace_set_filter_ips(&fprobe_ftrace_ops,
alist.addrs, alist.index, 1, 0);
#endif
}
if (alist.index > 0)
fprobe_set_ips(alist.addrs, alist.index, 1, 0);
mutex_unlock(&fprobe_mutex);
kfree(alist.addrs);