Messages in this thread | | | Date | Fri, 19 Jan 2018 09:17:07 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH] printk: drop redundant devkmsg_log_str memsets |
| |
On Fri, 19 Jan 2018 13:39:01 +0900 Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> wrote:
> We copy in null terminated strings "on" and "off", no > need to zero out devkmsg_log_str in control_devkmsg(). > > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > --- > kernel/printk/printk.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index d70927c384f3..9faddcfd3994 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -136,13 +136,10 @@ static int __init control_devkmsg(char *str) > /* > * Set sysctl string accordingly: > */ > - if (devkmsg_log == DEVKMSG_LOG_MASK_ON) { > - memset(devkmsg_log_str, 0, DEVKMSG_STR_MAX_SIZE); > - strncpy(devkmsg_log_str, "on", 2); > - } else if (devkmsg_log == DEVKMSG_LOG_MASK_OFF) { > - memset(devkmsg_log_str, 0, DEVKMSG_STR_MAX_SIZE); > - strncpy(devkmsg_log_str, "off", 3); > - } > + if (devkmsg_log == DEVKMSG_LOG_MASK_ON) > + strcpy(devkmsg_log_str, "on"); > + else if (devkmsg_log == DEVKMSG_LOG_MASK_OFF) > + strcpy(devkmsg_log_str, "off"); > /* else "ratelimit" which is set by default. */ > > /*
Yep, and even the sysctl checks for the terminating nul string, so there's no leaks of any kind.
Tested by adding: printk.devkmsg=on and running:
$ hexdump -C /proc/sys/kernel/printk_devkmsg 00000000 6f 6e 0a |on.| 00000003
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
| |