On Thu, Oct 26, 2023 at 10:13 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > The use of strlcat() is fragile at best, and we'd like to remove it from > the available string APIs in the kernel. Instead, use the safer seq_buf > APIs. > > Cc: Kalle Valo <kvalo@xxxxxxxxxx> > Cc: Johannes Berg <johannes.berg@xxxxxxxxx> > Cc: Max Chen <mxchen@xxxxxxxxxxxxxx> > Cc: Yang Shen <shenyang39@xxxxxxxxxx> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> > Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Justin Stitt <justinstitt@xxxxxxxxxx> > Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx> > Cc: Petr Mladek <pmladek@xxxxxxxx> > Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> > Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> > Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Jonathan Corbet <corbet@xxxxxxx> > Cc: Yun Zhou <yun.zhou@xxxxxxxxxxxxx> > Cc: Jacob Keller <jacob.e.keller@xxxxxxxxx> > Cc: Zhen Lei <thunder.leizhen@xxxxxxxxxx> > Cc: linux-trace-kernel@xxxxxxxxxxxxxxx > Cc: linux-wireless@xxxxxxxxxxxxxxx > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > --- > This is mainly an example of where/how to use the ongoing seq_buf > refactoring happening in the tracing tree: > https://lore.kernel.org/lkml/20231026170722.work.638-kees@xxxxxxxxxx/ I like it. C-strings and many of their associated apis are dodgy. This looks like a worthwhile replacement. I think many of my strncpy -> strscpy replacements could've easily been something along these lines as well. Happy to see robustness increasing in the kernel by means of replacing sketchy C-string stuff. > --- > drivers/net/wireless/ath/wil6210/wmi.c | 23 ++++++++++------------- > 1 file changed, 10 insertions(+), 13 deletions(-) > > diff --git a/drivers/net/wireless/ath/wil6210/wmi.c b/drivers/net/wireless/ath/wil6210/wmi.c > index 6fdb77d4c59e..45b8c651b8e2 100644 > --- a/drivers/net/wireless/ath/wil6210/wmi.c > +++ b/drivers/net/wireless/ath/wil6210/wmi.c > @@ -3159,36 +3159,34 @@ int wmi_suspend(struct wil6210_priv *wil) > return rc; > } > > -static void resume_triggers2string(u32 triggers, char *string, int str_size) > +static void resume_triggers2string(u32 triggers, struct seq_buf *s) > { > - string[0] = '\0'; > - > if (!triggers) { > - strlcat(string, " UNKNOWN", str_size); > + seq_buf_puts(s, " UNKNOWN"); > return; > } > > if (triggers & WMI_RESUME_TRIGGER_HOST) > - strlcat(string, " HOST", str_size); > + seq_buf_puts(s, " HOST") > > if (triggers & WMI_RESUME_TRIGGER_UCAST_RX) > - strlcat(string, " UCAST_RX", str_size); > + seq_buf_puts(s, " UCAST_RX"); > > if (triggers & WMI_RESUME_TRIGGER_BCAST_RX) > - strlcat(string, " BCAST_RX", str_size); > + seq_buf_puts(s, " BCAST_RX"); > > if (triggers & WMI_RESUME_TRIGGER_WMI_EVT) > - strlcat(string, " WMI_EVT", str_size); > + seq_buf_puts(s, " WMI_EVT"); > > if (triggers & WMI_RESUME_TRIGGER_DISCONNECT) > - strlcat(string, " DISCONNECT", str_size); > + seq_buf_puts(s, " DISCONNECT"); > } > > int wmi_resume(struct wil6210_priv *wil) > { > struct wil6210_vif *vif = ndev_to_vif(wil->main_ndev); > int rc; > - char string[100]; > + DECLARE_SEQ_BUF(s, 100); > struct { > struct wmi_cmd_hdr wmi; > struct wmi_traffic_resume_event evt; > @@ -3203,10 +3201,9 @@ int wmi_resume(struct wil6210_priv *wil) > WIL_WAIT_FOR_SUSPEND_RESUME_COMP); > if (rc) > return rc; > - resume_triggers2string(le32_to_cpu(reply.evt.resume_triggers), string, > - sizeof(string)); > + resume_triggers2string(le32_to_cpu(reply.evt.resume_triggers), s); > wil_dbg_pm(wil, "device resume %s, resume triggers:%s (0x%x)\n", > - reply.evt.status ? "failed" : "passed", string, > + reply.evt.status ? "failed" : "passed", seq_buf_cstr(s), > le32_to_cpu(reply.evt.resume_triggers)); > > return reply.evt.status; > -- > 2.34.1 > Thanks Justin
