[PATCH 05/15] print_integer, proc: rewrite /proc/thread-self via print_integer()

From: Alexey Dobriyan
Date: Mon Apr 20 2020 - 16:59:02 EST


Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
fs/proc/thread_self.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index f61ae53533f5..c29d37e3bd28 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -15,14 +15,20 @@ static const char *proc_thread_self_get_link(struct dentry *dentry,
struct pid_namespace *ns = proc_pid_ns(inode);
pid_t tgid = task_tgid_nr_ns(current, ns);
pid_t pid = task_pid_nr_ns(current, ns);
+ char buf[10 + 6 + 10 + 1];
+ char *p = buf + sizeof(buf);
char *name;

if (!pid)
return ERR_PTR(-ENOENT);
- name = kmalloc(10 + 6 + 10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC);
+ name = kmalloc(sizeof(buf), dentry ? GFP_KERNEL : GFP_ATOMIC);
if (unlikely(!name))
return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
- sprintf(name, "%u/task/%u", tgid, pid);
+ *--p = '\0';
+ p = _print_integer_u32(p, pid);
+ p = memcpy(p - 6, "/task/", 6);
+ p = _print_integer_u32(p, tgid);
+ memcpy(name, p, buf + sizeof(buf) - p);
set_delayed_call(done, kfree_link, name);
return name;
}
--
2.24.1