Merge tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/ker…

…nel/git/pmladek/printk

Pull printk updates from Petr Mladek:

 - Help userspace log daemons to catch up with a flood of messages. They
   will get woken after each message even if the console is far behind
   and handled by another process.

 - Flush printk safe buffers safely even when panic() happens in the
   normal context.

 - Fix possible va_list reuse when race happened in printk_safe().

 - Remove %pCr printf format to prevent sleeping in the atomic context.

 - Misc vsprintf code cleanup.

* tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  printk: drop in_nmi check from printk_safe_flush_on_panic()
  lib/vsprintf: Remove atomic-unsafe support for %pCr
  serial: sh-sci: Stop using printk format %pCr
  thermal: bcm2835: Stop using printk format %pCr
  clk: renesas: cpg-mssr: Stop using printk format %pCr
  printk: fix possible reuse of va_list variable
  printk: wake up klogd in vprintk_emit
  vsprintf: Tweak pF/pf comment
  lib/vsprintf: Mark expected switch fall-through
  lib/vsprintf: Replace space with '_' before crng is ready
  lib/vsprintf: Deduplicate pointer_string()
  lib/vsprintf: Move pointer_string() upper
  lib/vsprintf: Make flag_spec global
  lib/vsprintf: Make strspec global
  lib/vsprintf: Make dec_spec global
  lib/test_printf: Mark big constant with UL

Documentation/core-api/printk-formats.rst

@@ -419,11 +419,10 @@ struct clk
 
 	%pC	pll1
 	%pCn	pll1
-	%pCr	1560000000
 
 For printing struct clk structures. %pC and %pCn print the name
 (Common Clock Framework) or address (legacy clock framework) of the
-structure; %pCr prints the current clock rate.
+structure.
 
 Passed by reference.
 

drivers/clk/renesas/renesas-cpg-mssr.c

@@ -258,8 +258,9 @@ struct clk *cpg_mssr_clk_src_twocell_get(struct of_phandle_args *clkspec,
 		dev_err(dev, "Cannot get %s clock %u: %ld", type, clkidx,
 		       PTR_ERR(clk));
 	else
-		dev_dbg(dev, "clock (%u, %u) is %pC at %pCr Hz\n",
-			clkspec->args[0], clkspec->args[1], clk, clk);
+		dev_dbg(dev, "clock (%u, %u) is %pC at %lu Hz\n",
+			clkspec->args[0], clkspec->args[1], clk,
+			clk_get_rate(clk));
 	return clk;
 }
 
@@ -326,7 +327,7 @@ static void __init cpg_mssr_register_core_clk(const struct cpg_core_clk *core,
 	if (IS_ERR_OR_NULL(clk))
 		goto fail;
 
-	dev_dbg(dev, "Core clock %pC at %pCr Hz\n", clk, clk);
+	dev_dbg(dev, "Core clock %pC at %lu Hz\n", clk, clk_get_rate(clk));
 	priv->clks[id] = clk;
 	return;
 
@@ -392,7 +393,7 @@ static void __init cpg_mssr_register_mod_clk(const struct mssr_mod_clk *mod,
 	if (IS_ERR(clk))
 		goto fail;
 
-	dev_dbg(dev, "Module clock %pC at %pCr Hz\n", clk, clk);
+	dev_dbg(dev, "Module clock %pC at %lu Hz\n", clk, clk_get_rate(clk));
 	priv->clks[id] = clk;
 	priv->smstpcr_saved[clock->index / 32].mask |= BIT(clock->index % 32);
 	return;

drivers/thermal/broadcom/bcm2835_thermal.c

@@ -213,8 +213,8 @@ static int bcm2835_thermal_probe(struct platform_device *pdev)
 	rate = clk_get_rate(data->clk);
 	if ((rate < 1920000) || (rate > 5000000))
 		dev_warn(&pdev->dev,
-			 "Clock %pCn running at %pCr Hz is outside of the recommended range: 1.92 to 5MHz\n",
-			 data->clk, data->clk);
+			 "Clock %pCn running at %lu Hz is outside of the recommended range: 1.92 to 5MHz\n",
+			 data->clk, rate);
 
 	/* register of thermal sensor and get info from DT */
 	tz = thermal_zone_of_sensor_register(&pdev->dev, 0, data,

drivers/tty/serial/sh-sci.c

@@ -2724,8 +2724,8 @@ static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
 			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
 				PTR_ERR(clk));
 		else
-			dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
-				clk, clk);
+			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
+				clk, clk_get_rate(clk));
 		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
 	}
 	return 0;

kernel/printk/printk.c

@@ -1908,6 +1908,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 		preempt_enable();
 	}
 
+	wake_up_klogd();
 	return printed_len;
 }
 EXPORT_SYMBOL(vprintk_emit);
@@ -2289,9 +2290,7 @@ void console_unlock(void)
 {
 	static char ext_text[CONSOLE_EXT_LOG_MAX];
 	static char text[LOG_LINE_MAX + PREFIX_MAX];
-	static u64 seen_seq;
 	unsigned long flags;
-	bool wake_klogd = false;
 	bool do_cond_resched, retry;
 
 	if (console_suspended) {
@@ -2335,11 +2334,6 @@ void console_unlock(void)
 
 		printk_safe_enter_irqsave(flags);
 		raw_spin_lock(&logbuf_lock);
-		if (seen_seq != log_next_seq) {
-			wake_klogd = true;
-			seen_seq = log_next_seq;
-		}
-
 		if (console_seq < log_first_seq) {
 			len = sprintf(text, "** %u printk messages dropped **\n",
 				      (unsigned)(log_first_seq - console_seq));
@@ -2397,7 +2391,7 @@ void console_unlock(void)
 
 		if (console_lock_spinning_disable_and_check()) {
 			printk_safe_exit_irqrestore(flags);
-			goto out;
+			return;
 		}
 
 		printk_safe_exit_irqrestore(flags);
@@ -2429,10 +2423,6 @@ void console_unlock(void)
 
 	if (retry && console_trylock())
 		goto again;
-
-out:
-	if (wake_klogd)
-		wake_up_klogd();
 }
 EXPORT_SYMBOL(console_unlock);
 

kernel/printk/printk_safe.c

@@ -82,6 +82,7 @@ static __printf(2, 0) int printk_safe_log_store(struct printk_safe_seq_buf *s,
 {
 	int add;
 	size_t len;
+	va_list ap;
 
 again:
 	len = atomic_read(&s->len);
@@ -100,7 +101,9 @@ static __printf(2, 0) int printk_safe_log_store(struct printk_safe_seq_buf *s,
 	if (!len)
 		smp_rmb();
 
-	add = vscnprintf(s->buffer + len, sizeof(s->buffer) - len, fmt, args);
+	va_copy(ap, args);
+	add = vscnprintf(s->buffer + len, sizeof(s->buffer) - len, fmt, ap);
+	va_end(ap);
 	if (!add)
 		return 0;
 
@@ -278,7 +281,7 @@ void printk_safe_flush_on_panic(void)
 	 * Make sure that we could access the main ring buffer.
 	 * Do not risk a double release when more CPUs are up.
 	 */
-	if (in_nmi() && raw_spin_is_locked(&logbuf_lock)) {
+	if (raw_spin_is_locked(&logbuf_lock)) {
 		if (num_online_cpus() > 1)
 			return;
 

lib/test_printf.c

@@ -204,7 +204,7 @@ test_string(void)
 #if BITS_PER_LONG == 64
 
 #define PTR_WIDTH 16
-#define PTR ((void *)0xffff0123456789ab)
+#define PTR ((void *)0xffff0123456789abUL)
 #define PTR_STR "ffff0123456789ab"
 #define ZEROS "00000000"	/* hex 32 zero bits */