Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Stop synchronizing kernel log buffer readers by logbuf_lock. As a
   result, the access to the buffer is fully lockless now.

   Note that printk() itself still uses locks because it tries to flush
   the messages to the console immediately. Also the per-CPU temporary
   buffers are still there because they prevent infinite recursion and
   serialize backtraces from NMI. All this is going to change in the
   future.

 - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock
   removal.

 - Make bstr_printf() aware that %pf and %pF formats could deference the
   given pointer.

 - Show also page flags by %pGp format.

 - Clarify the documentation for plain pointer printing.

 - Do not show no_hash_pointers warning multiple times.

 - Update Senozhatsky email address.

 - Some clean up.

* tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits)
  lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()
  printk: clarify the documentation for plain pointer printing
  kernel/printk.c: Fixed mundane typos
  printk: rename vprintk_func to vprintk
  vsprintf: dump full information of page flags in pGp
  mm, slub: don't combine pr_err with INFO
  mm, slub: use pGp to print page flags
  MAINTAINERS: update Senozhatsky email address
  lib/vsprintf: do not show no_hash_pointers message multiple times
  printk: console: remove unnecessary safe buffer usage
  printk: kmsg_dump: remove _nolock() variants
  printk: remove logbuf_lock
  printk: introduce a kmsg_dump iterator
  printk: kmsg_dumper: remove @active field
  printk: add syslog_lock
  printk: use atomic64_t for devkmsg_user.seq
  printk: use seqcount_latch for clear_seq
  printk: introduce CONSOLE_LOG_MAX
  printk: consolidate kmsg_dump_get_buffer/syslog_print_all code
  printk: refactor kmsg_dump_get_buffer()
  ...

1 files changed, 69 insertions, 9 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 41ddc353ebb8..6c56c62fd9a5 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1916,6 +1916,66 @@ char *format_flags(char *buf, char *end, unsigned long flags,
 	return buf;
 }
 
+struct page_flags_fields {
+	int width;
+	int shift;
+	int mask;
+	const struct printf_spec *spec;
+	const char *name;
+};
+
+static const struct page_flags_fields pff[] = {
+	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
+	 &default_dec_spec, "section"},
+	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
+	 &default_dec_spec, "node"},
+	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
+	 &default_dec_spec, "zone"},
+	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
+	 &default_flag_spec, "lastcpupid"},
+	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
+	 &default_flag_spec, "kasantag"},
+};
+
+static
+char *format_page_flags(char *buf, char *end, unsigned long flags)
+{
+	unsigned long main_flags = flags & (BIT(NR_PAGEFLAGS) - 1);
+	bool append = false;
+	int i;
+
+	/* Page flags from the main area. */
+	if (main_flags) {
+		buf = format_flags(buf, end, main_flags, pageflag_names);
+		append = true;
+	}
+
+	/* Page flags from the fields area */
+	for (i = 0; i < ARRAY_SIZE(pff); i++) {
+		/* Skip undefined fields. */
+		if (!pff[i].width)
+			continue;
+
+		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
+		if (append) {
+			if (buf < end)
+				*buf = '|';
+			buf++;
+		}
+
+		buf = string(buf, end, pff[i].name, default_str_spec);
+		if (buf < end)
+			*buf = '=';
+		buf++;
+		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
+			     *pff[i].spec);
+
+		append = true;
+	}
+
+	return buf;
+}
+
 static noinline_for_stack
 char *flags_string(char *buf, char *end, void *flags_ptr,
 		   struct printf_spec spec, const char *fmt)
@@ -1928,11 +1988,7 @@ char *flags_string(char *buf, char *end, void *flags_ptr,
 
 	switch (fmt[1]) {
 	case 'p':
-		flags = *(unsigned long *)flags_ptr;
-		/* Remove zone id */
-		flags &= (1UL << NR_PAGEFLAGS) - 1;
-		names = pageflag_names;
-		break;
+		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
 	case 'v':
 		flags = *(unsigned long *)flags_ptr;
 		names = vmaflag_names;
@@ -2096,6 +2152,9 @@ EXPORT_SYMBOL_GPL(no_hash_pointers);
 
 static int __init no_hash_pointers_enable(char *str)
 {
+	if (no_hash_pointers)
+		return 0;
+
 	no_hash_pointers = true;
 
 	pr_warn("**********************************************************\n");
@@ -2186,7 +2245,9 @@ early_param("no_hash_pointers", no_hash_pointers_enable);
  *       Implements a "recursive vsnprintf".
  *       Do not use this feature without some mechanism to verify the
  *       correctness of the format string and va_list arguments.
- * - 'K' For a kernel pointer that should be hidden from unprivileged users
+ * - 'K' For a kernel pointer that should be hidden from unprivileged users.
+ *       Use only for procfs, sysfs and similar files, not printk(); please
+ *       read the documentation (path below) first.
  * - 'NF' For a netdev_features_t
  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
  *            a certain separator (' ' by default):
@@ -2225,7 +2286,8 @@ early_param("no_hash_pointers", no_hash_pointers_enable);
  *		Without an option prints the full name of the node
  *		f full name
  *		P node name, including a possible unit address
- * - 'x' For printing the address. Equivalent to "%lx".
+ * - 'x' For printing the address unmodified. Equivalent to "%lx".
+ *       Please read the documentation (path below) before using!
  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
  *           or user (u) memory to probe, and:
@@ -3135,8 +3197,6 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 			switch (*fmt) {
 			case 'S':
 			case 's':
-			case 'F':
-			case 'f':
 			case 'x':
 			case 'K':
 			case 'e':