Merge tag 'printk-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Make %pK behave the same as %p for kptr_restrict == 0 also with
   no_hash_pointers parameter

 - Ignore the default console in the device tree also when console=null
   or console="" is used on the command line

 - Document console=null and console="" behavior

 - Prevent a deadlock and a livelock caused by console_lock in panic()

 - Make console_lock available for panicking CPU

 - Fast query for the next to-be-used sequence number

 - Use the expected return values in printk.devkmsg __setup handler

 - Use the correct atomic operations in wake_up_klogd() irq_work handler

 - Avoid possible unaligned access when handling %4cc printing format

* tag 'printk-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: fix return value of printk.devkmsg __setup handler
  vsprintf: Fix %pK with kptr_restrict == 0
  printk: make suppress_panic_printk static
  printk: Set console_set_on_cmdline=1 when __add_preferred_console() is called with user_specified == true
  Docs: printk: add 'console=null|""' to admin/kernel-parameters
  printk: use atomic updates for klogd work
  printk: Drop console_sem during panic
  printk: Avoid livelock with heavy printk during panic
  printk: disable optimistic spin during panic
  printk: Add panic_in_progress helper
  vsprintf: Move space out of string literals in fourcc_string()
  vsprintf: Fix potential unaligned access
  printk: ringbuffer: Improve prb_next_seq() performance

1 files changed, 29 insertions, 20 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 36574a806a81..53fe73a48adf 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -49,10 +49,15 @@
 
 #include <asm/page.h>		/* for PAGE_SIZE */
 #include <asm/byteorder.h>	/* cpu_to_le16 */
+#include <asm/unaligned.h>
 
 #include <linux/string_helpers.h>
 #include "kstrtox.h"
 
+/* Disable pointer hashing if requested */
+bool no_hash_pointers __ro_after_init;
+EXPORT_SYMBOL_GPL(no_hash_pointers);
+
 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
 {
 	const char *cp;
@@ -850,6 +855,19 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
 	return pointer_string(buf, end, (const void *)hashval, spec);
 }
 
+static char *default_pointer(char *buf, char *end, const void *ptr,
+			     struct printf_spec spec)
+{
+	/*
+	 * default is to _not_ leak addresses, so hash before printing,
+	 * unless no_hash_pointers is specified on the command line.
+	 */
+	if (unlikely(no_hash_pointers))
+		return pointer_string(buf, end, ptr, spec);
+
+	return ptr_to_id(buf, end, ptr, spec);
+}
+
 int kptr_restrict __read_mostly;
 
 static noinline_for_stack
@@ -859,7 +877,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
 	switch (kptr_restrict) {
 	case 0:
 		/* Handle as %p, hash and do _not_ leak addresses. */
-		return ptr_to_id(buf, end, ptr, spec);
+		return default_pointer(buf, end, ptr, spec);
 	case 1: {
 		const struct cred *cred;
 
@@ -1763,7 +1781,7 @@ char *fourcc_string(char *buf, char *end, const u32 *fourcc,
 	char output[sizeof("0123 little-endian (0x01234567)")];
 	char *p = output;
 	unsigned int i;
-	u32 val;
+	u32 orig, val;
 
 	if (fmt[1] != 'c' || fmt[2] != 'c')
 		return error_string(buf, end, "(%p4?)", spec);
@@ -1771,21 +1789,23 @@ char *fourcc_string(char *buf, char *end, const u32 *fourcc,
 	if (check_pointer(&buf, end, fourcc, spec))
 		return buf;
 
-	val = *fourcc & ~BIT(31);
+	orig = get_unaligned(fourcc);
+	val = orig & ~BIT(31);
 
-	for (i = 0; i < sizeof(*fourcc); i++) {
+	for (i = 0; i < sizeof(u32); i++) {
 		unsigned char c = val >> (i * 8);
 
 		/* Print non-control ASCII characters as-is, dot otherwise */
 		*p++ = isascii(c) && isprint(c) ? c : '.';
 	}
 
-	strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian");
+	*p++ = ' ';
+	strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
 	p += strlen(p);
 
 	*p++ = ' ';
 	*p++ = '(';
-	p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32));
+	p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
 	*p++ = ')';
 	*p = '\0';
 
@@ -2225,10 +2245,6 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
 	return widen_string(buf, buf - buf_start, end, spec);
 }
 
-/* Disable pointer hashing if requested */
-bool no_hash_pointers __ro_after_init;
-EXPORT_SYMBOL_GPL(no_hash_pointers);
-
 int __init no_hash_pointers_enable(char *str)
 {
 	if (no_hash_pointers)
@@ -2457,7 +2473,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 	case 'e':
 		/* %pe with a non-ERR_PTR gets treated as plain %p */
 		if (!IS_ERR(ptr))
-			break;
+			return default_pointer(buf, end, ptr, spec);
 		return err_ptr(buf, end, ptr, spec);
 	case 'u':
 	case 'k':
@@ -2467,16 +2483,9 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 		default:
 			return error_string(buf, end, "(einval)", spec);
 		}
+	default:
+		return default_pointer(buf, end, ptr, spec);
 	}
-
-	/*
-	 * default is to _not_ leak addresses, so hash before printing,
-	 * unless no_hash_pointers is specified on the command line.
-	 */
-	if (unlikely(no_hash_pointers))
-		return pointer_string(buf, end, ptr, spec);
-	else
-		return ptr_to_id(buf, end, ptr, spec);
 }
 
 /*