[PATCH v2 2/2] kernel-trace: Less calls for iput() in create_trace_uprobe() after error detection

SF Markus Elfring
2014-11-16T19:22:33Z

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 16 Nov 2014 19:49:39 +0100

The iput() function was called in three cases by the create_trace_uprobe()
function during error handling even if the passed variable contained still
a null pointer. This implementation detail could be improved by the
introduction of another jump label.

Suggested-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
kernel/trace/trace_uprobe.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index ec002c0..a0288f2 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -434,19 +434,24 @@ static int create_trace_uprobe(int argc, char **argv)
arg = strchr(argv[1], ':');
if (!arg) {
ret = -EINVAL;
- goto fail_address_parse;
+ goto fail_address_parse2;
}

*arg++ = '\0';
filename = argv[1];
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
- goto fail_address_parse;
+ goto fail_address_parse2;

inode = igrab(path.dentry->d_inode);
path_put(&path);

- if (!inode || !S_ISREG(inode->i_mode)) {
+ if (!inode) {
+ ret = -EINVAL;
+ goto fail_address_parse2;
+ }
+
+ if (!S_ISREG(inode->i_mode)) {
ret = -EINVAL;
goto fail_address_parse;
}
@@ -554,6 +559,7 @@ error:
fail_address_parse:
iput(inode);

+fail_address_parse2:
pr_info("Failed to parse address or file.\n");

return ret;
--
2.1.3