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authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-21 09:34:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-21 09:34:29 -0700
commit56c1e8343494f0a315c99964ea1a952478394a8d (patch)
tree174cc3f4782d00fe0f8e47bff1ae8102d26cdccc
parentf97c81dc6ca5996560b3944064f63fc87eb18d00 (diff)
parentae88de56a1893bdccc7b5af8c12556de649d675e (diff)
downloadlinux-56c1e8343494f0a315c99964ea1a952478394a8d.tar.bz2
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
-rw-r--r--Documentation/ABI/testing/dev-kmsg15
-rw-r--r--kernel/printk/braille.c15
-rw-r--r--kernel/printk/printk.c24
-rw-r--r--lib/test_printf.c5
-rw-r--r--lib/vsprintf.c13
5 files changed, 50 insertions, 22 deletions
diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg
index fff817efa508..f307506eb54c 100644
--- a/Documentation/ABI/testing/dev-kmsg
+++ b/Documentation/ABI/testing/dev-kmsg
@@ -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
diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c
index 1d21ebacfdb8..17a9591e54ff 100644
--- a/kernel/printk/braille.c
+++ b/kernel/printk/braille.c
@@ -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");
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 1888f6a3b694..ca65327a6de8 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -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);
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 944eb50f3862..5d94cbff2120 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -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]);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index b0967cf17137..e78017a3e1bd 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -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);