[PATCH 4.19 06/34] tracing/kprobe: Fix kprobe_on_func_entry() modification

Greg Kroah-Hartman
2021-09-24T12:52:56Z

From: Li Huafei <lihuafei1@huawei.com>

The commit 960434acef37 ("tracing/kprobe: Fix to support kretprobe
events on unloaded modules") backport from v5.11, which modifies the
return value of kprobe_on_func_entry(). However, there is no adaptation
modification in create_trace_kprobe(), resulting in the exact opposite
behavior. Now we need to return an error immediately only if
kprobe_on_func_entry() returns -EINVAL.

Fixes: 960434acef37 ("tracing/kprobe: Fix to support kretprobe events on unloaded modules")
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace_kprobe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -836,8 +836,9 @@ static int create_trace_kprobe(int argc,
pr_info("Failed to parse either an address or a symbol.\n");
return ret;
}
+ /* Defer the ENOENT case until register kprobe */
if (offset && is_return &&
- !kprobe_on_func_entry(NULL, symbol, offset)) {
+ kprobe_on_func_entry(NULL, symbol, offset) == -EINVAL) {
pr_info("Given offset is not valid for return probe.\n");
return -EINVAL;
}