Commit 56c1e834 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'printk-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 

Pull printk updates from Petr Mladek:

 - Fix off-by-one error when calculating messages that might fit into
   kmsg buffer. It causes occasional omitting of the last message.

 - Add missing pointer check in %pD format modifier handling.

 - Some clean up

* tag 'printk-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  ABI: Update dev-kmsg documentation to match current kernel behaviour
  printk: Replace strncmp() with str_has_prefix()
  lib/test_printf: Remove obvious comments from %pd and %pD tests
  lib/test_printf: Add test of null/invalid pointer dereference for dentry
  vsprintf: Prevent crash when dereferencing invalid pointers for %pD
  printk: Do not lose last line in kmsg buffer dump
parents f97c81dc ae88de56

Documentation/ABI/testing/dev-kmsg

+7 −8
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ Description: The /dev/kmsg character device node provides userspace access 
		The logged line can be prefixed with a <N> syslog prefix, which

		carries the syslog priority and facility. The single decimal

		prefix number is composed of the 3 lowest bits being the syslog

		priority and the higher bits the syslog facility number.

		priority and the next 8 bits the syslog facility number.



		If no prefix is given, the priority number is the default kernel

		log priority and the facility number is set to LOG_USER (1). It
@@ -90,13 +90,12 @@ Description: The /dev/kmsg character device node provides userspace access 
		  +sound:card0 - subsystem:devname



		The flags field carries '-' by default. A 'c' indicates a

		fragment of a line. All following fragments are flagged with

		'+'. Note, that these hints about continuation lines are not

		necessarily correct, and the stream could be interleaved with

		unrelated messages, but merging the lines in the output

		usually produces better human readable results. A similar

		logic is used internally when messages are printed to the

		console, /proc/kmsg or the syslog() syscall.

		fragment of a line. Note, that these hints about continuation

		lines are not necessarily correct, and the stream could be

		interleaved with unrelated messages, but merging the lines in

		the output usually produces better human readable results. A

		similar logic is used internally when messages are printed to

		the console, /proc/kmsg or the syslog() syscall.



		By default, kernel tries to avoid fragments by concatenating

		when it can and fragments are rare; however, when extended

kernel/printk/braille.c

+11 −4
Original line number Diff line number Diff line
@@ -11,11 +11,18 @@ 


int _braille_console_setup(char **str, char **brl_options)

{

	if (!strncmp(*str, "brl,", 4)) {

	size_t len;



	len = str_has_prefix(*str, "brl,");

	if (len) {

		*brl_options = "";

		*str += 4;

	} else if (!strncmp(*str, "brl=", 4)) {

		*brl_options = *str + 4;

		*str += len;

		return 0;

	}



	len = str_has_prefix(*str, "brl=");

	if (len) {

		*brl_options = *str + len;

		*str = strchr(*brl_options, ',');

		if (!*str) {

			pr_err("need port name after brl=\n");

kernel/printk/printk.c

+17 −7
Original line number Diff line number Diff line
@@ -118,19 +118,29 @@ static unsigned int __read_mostly devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT; 


static int __control_devkmsg(char *str)

{

	size_t len;



	if (!str)

		return -EINVAL;



	if (!strncmp(str, "on", 2)) {

	len = str_has_prefix(str, "on");

	if (len) {

		devkmsg_log = DEVKMSG_LOG_MASK_ON;

		return 2;

	} else if (!strncmp(str, "off", 3)) {

		return len;

	}



	len = str_has_prefix(str, "off");

	if (len) {

		devkmsg_log = DEVKMSG_LOG_MASK_OFF;

		return 3;

	} else if (!strncmp(str, "ratelimit", 9)) {

		return len;

	}



	len = str_has_prefix(str, "ratelimit");

	if (len) {

		devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT;

		return 9;

		return len;

	}



	return -EINVAL;

}
@@ -3274,7 +3284,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog, 
	/* move first record forward until length fits into the buffer */

	seq = dumper->cur_seq;

	idx = dumper->cur_idx;

	while (l > size && seq < dumper->next_seq) {

	while (l >= size && seq < dumper->next_seq) {

		struct printk_log *msg = log_from_idx(idx);



		l -= msg_print_text(msg, true, time, NULL, 0);

lib/test_printf.c

+5 −0
Original line number Diff line number Diff line
@@ -455,6 +455,11 @@ dentry(void) 
	test("foo", "%pd", &test_dentry[0]);

	test("foo", "%pd2", &test_dentry[0]);



	test("(null)", "%pd", NULL);

	test("(efault)", "%pd", PTR_INVALID);

	test("(null)", "%pD", NULL);

	test("(efault)", "%pD", PTR_INVALID);



	test("romeo", "%pd", &test_dentry[3]);

	test("alfa/romeo", "%pd2", &test_dentry[3]);

	test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);

lib/vsprintf.c

+10 −3
Original line number Diff line number Diff line
@@ -869,6 +869,15 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp 
	return widen_string(buf, n, end, spec);

}



static noinline_for_stack

char *file_dentry_name(char *buf, char *end, const struct file *f,

			struct printf_spec spec, const char *fmt)

{

	if (check_pointer(&buf, end, f, spec))

		return buf;



	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);

}

#ifdef CONFIG_BLOCK

static noinline_for_stack

char *bdev_name(char *buf, char *end, struct block_device *bdev,
@@ -2166,9 +2175,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, 
	case 'C':

		return clock(buf, end, ptr, spec, fmt);

	case 'D':

		return dentry_name(buf, end,

				   ((const struct file *)ptr)->f_path.dentry,

				   spec, fmt);

		return file_dentry_name(buf, end, ptr, spec, fmt);

#ifdef CONFIG_BLOCK

	case 'g':

		return bdev_name(buf, end, ptr, spec, fmt);

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