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-rw-r--r--Documentation/core-api/printk-formats.rst5
-rw-r--r--kernel/printk/printk.c86
-rw-r--r--lib/vsprintf.c216
3 files changed, 158 insertions, 149 deletions
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index 86023c33906f..ff48b55040ef 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -420,9 +420,8 @@ struct clk
%pC pll1
%pCn pll1
-For printing struct clk structures. %pC and %pCn print the name
-(Common Clock Framework) or address (legacy clock framework) of the
-structure.
+For printing struct clk structures. %pC and %pCn print the name of the clock
+(Common Clock Framework) or a unique 32-bit ID (legacy clock framework).
Passed by reference.
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 9bf5404397e0..b77150ad1965 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -16,6 +16,8 @@
* 01Mar01 Andrew Morton
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/tty.h>
@@ -192,16 +194,7 @@ int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
return 0;
}
-/*
- * Number of registered extended console drivers.
- *
- * If extended consoles are present, in-kernel cont reassembly is disabled
- * and each fragment is stored as a separate log entry with proper
- * continuation flag so that every emitted message has full metadata. This
- * doesn't change the result for regular consoles or /proc/kmsg. For
- * /dev/kmsg, as long as the reader concatenates messages according to
- * consecutive continuation flags, the end result should be the same too.
- */
+/* Number of registered extended console drivers. */
static int nr_ext_console_drivers;
/*
@@ -423,6 +416,7 @@ static u32 log_next_idx;
/* the next printk record to write to the console */
static u64 console_seq;
static u32 console_idx;
+static u64 exclusive_console_stop_seq;
/* the next printk record to read after the last 'clear' command */
static u64 clear_seq;
@@ -437,6 +431,7 @@ static u32 clear_idx;
/* record buffer */
#define LOG_ALIGN __alignof__(struct printk_log)
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+#define LOG_BUF_LEN_MAX (u32)(1 << 31)
static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
static char *log_buf = __log_buf;
static u32 log_buf_len = __LOG_BUF_LEN;
@@ -1037,18 +1032,28 @@ void log_buf_vmcoreinfo_setup(void)
static unsigned long __initdata new_log_buf_len;
/* we practice scaling the ring buffer by powers of 2 */
-static void __init log_buf_len_update(unsigned size)
+static void __init log_buf_len_update(u64 size)
{
+ if (size > (u64)LOG_BUF_LEN_MAX) {
+ size = (u64)LOG_BUF_LEN_MAX;
+ pr_err("log_buf over 2G is not supported.\n");
+ }
+
if (size)
size = roundup_pow_of_two(size);
if (size > log_buf_len)
- new_log_buf_len = size;
+ new_log_buf_len = (unsigned long)size;
}
/* save requested log_buf_len since it's too early to process it */
static int __init log_buf_len_setup(char *str)
{
- unsigned size = memparse(str, &str);
+ u64 size;
+
+ if (!str)
+ return -EINVAL;
+
+ size = memparse(str, &str);
log_buf_len_update(size);
@@ -1093,7 +1098,7 @@ void __init setup_log_buf(int early)
{
unsigned long flags;
char *new_log_buf;
- int free;
+ unsigned int free;
if (log_buf != __log_buf)
return;
@@ -1113,7 +1118,7 @@ void __init setup_log_buf(int early)
}
if (unlikely(!new_log_buf)) {
- pr_err("log_buf_len: %ld bytes not available\n",
+ pr_err("log_buf_len: %lu bytes not available\n",
new_log_buf_len);
return;
}
@@ -1126,8 +1131,8 @@ void __init setup_log_buf(int early)
memcpy(log_buf, __log_buf, __LOG_BUF_LEN);
logbuf_unlock_irqrestore(flags);
- pr_info("log_buf_len: %d bytes\n", log_buf_len);
- pr_info("early log buf free: %d(%d%%)\n",
+ pr_info("log_buf_len: %u bytes\n", log_buf_len);
+ pr_info("early log buf free: %u(%u%%)\n",
free, (free * 100) / __LOG_BUF_LEN);
}
@@ -1767,12 +1772,8 @@ static void cont_flush(void)
static bool cont_add(int facility, int level, enum log_flags flags, const char *text, size_t len)
{
- /*
- * If ext consoles are present, flush and skip in-kernel
- * continuation. See nr_ext_console_drivers definition. Also, if
- * the line gets too long, split it up in separate records.
- */
- if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) {
+ /* If the line gets too long, split it up in separate records. */
+ if (cont.len + len > sizeof(cont.buf)) {
cont_flush();
return false;
}
@@ -1795,9 +1796,6 @@ static bool cont_add(int facility, int level, enum log_flags flags, const char *
cont_flush();
}
- if (cont.len > (sizeof(cont.buf) * 80) / 100)
- cont_flush();
-
return true;
}
@@ -1889,8 +1887,9 @@ asmlinkage int vprintk_emit(int facility, int level,
const char *fmt, va_list args)
{
int printed_len;
- bool in_sched = false;
+ bool in_sched = false, pending_output;
unsigned long flags;
+ u64 curr_log_seq;
if (level == LOGLEVEL_SCHED) {
level = LOGLEVEL_DEFAULT;
@@ -1902,11 +1901,13 @@ asmlinkage int vprintk_emit(int facility, int level,
/* This stops the holder of console_sem just where we want him */
logbuf_lock_irqsave(flags);
+ curr_log_seq = log_next_seq;
printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args);
+ pending_output = (curr_log_seq != log_next_seq);
logbuf_unlock_irqrestore(flags);
/* If called from the scheduler, we can not call up(). */
- if (!in_sched) {
+ if (!in_sched && pending_output) {
/*
* Disable preemption to avoid being preempted while holding
* console_sem which would prevent anyone from printing to
@@ -1923,7 +1924,8 @@ asmlinkage int vprintk_emit(int facility, int level,
preempt_enable();
}
- wake_up_klogd();
+ if (pending_output)
+ wake_up_klogd();
return printed_len;
}
EXPORT_SYMBOL(vprintk_emit);
@@ -2009,6 +2011,7 @@ static u64 syslog_seq;
static u32 syslog_idx;
static u64 console_seq;
static u32 console_idx;
+static u64 exclusive_console_stop_seq;
static u64 log_first_seq;
static u32 log_first_idx;
static u64 log_next_seq;
@@ -2351,8 +2354,9 @@ again:
printk_safe_enter_irqsave(flags);
raw_spin_lock(&logbuf_lock);
if (console_seq < log_first_seq) {
- len = sprintf(text, "** %u printk messages dropped **\n",
- (unsigned)(log_first_seq - console_seq));
+ len = sprintf(text,
+ "** %llu printk messages dropped **\n",
+ log_first_seq - console_seq);
/* messages are gone, move to first one */
console_seq = log_first_seq;
@@ -2376,6 +2380,12 @@ skip:
goto skip;
}
+ /* Output to all consoles once old messages replayed. */
+ if (unlikely(exclusive_console &&
+ console_seq >= exclusive_console_stop_seq)) {
+ exclusive_console = NULL;
+ }
+
len += msg_print_text(msg,
console_msg_format & MSG_FORMAT_SYSLOG,
text + len,
@@ -2418,10 +2428,6 @@ skip:
console_locked = 0;
- /* Release the exclusive_console once it is used */
- if (unlikely(exclusive_console))
- exclusive_console = NULL;
-
raw_spin_unlock(&logbuf_lock);
up_console_sem();
@@ -2688,8 +2694,7 @@ void register_console(struct console *newcon)
}
if (newcon->flags & CON_EXTENDED)
- if (!nr_ext_console_drivers++)
- pr_info("printk: continuation disabled due to ext consoles, expect more fragments in /dev/kmsg\n");
+ nr_ext_console_drivers++;
if (newcon->flags & CON_PRINTBUFFER) {
/*
@@ -2699,13 +2704,18 @@ void register_console(struct console *newcon)
logbuf_lock_irqsave(flags);
console_seq = syslog_seq;
console_idx = syslog_idx;
- logbuf_unlock_irqrestore(flags);
/*
* We're about to replay the log buffer. Only do this to the
* just-registered console to avoid excessive message spam to
* the already-registered consoles.
+ *
+ * Set exclusive_console with disabled interrupts to reduce
+ * race window with eventual console_flush_on_panic() that
+ * ignores console_lock.
*/
exclusive_console = newcon;
+ exclusive_console_stop_seq = console_seq;
+ logbuf_unlock_irqrestore(flags);
}
console_unlock();
console_sysfs_notify();
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 376de10929b3..ad4fbe5bc730 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -613,6 +613,109 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
}
static noinline_for_stack
+char *pointer_string(char *buf, char *end, const void *ptr,
+ struct printf_spec spec)
+{
+ spec.base = 16;
+ spec.flags |= SMALL;
+ if (spec.field_width == -1) {
+ spec.field_width = 2 * sizeof(ptr);
+ spec.flags |= ZEROPAD;
+ }
+
+ return number(buf, end, (unsigned long int)ptr, spec);
+}
+
+/* Make pointers available for printing early in the boot sequence. */
+static int debug_boot_weak_hash __ro_after_init;
+
+static int __init debug_boot_weak_hash_enable(char *str)
+{
+ debug_boot_weak_hash = 1;
+ pr_info("debug_boot_weak_hash enabled\n");
+ return 0;
+}
+early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
+
+static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
+static siphash_key_t ptr_key __read_mostly;
+
+static void enable_ptr_key_workfn(struct work_struct *work)
+{
+ get_random_bytes(&ptr_key, sizeof(ptr_key));
+ /* Needs to run from preemptible context */
+ static_branch_disable(&not_filled_random_ptr_key);
+}
+
+static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
+
+static void fill_random_ptr_key(struct random_ready_callback *unused)
+{
+ /* This may be in an interrupt handler. */
+ queue_work(system_unbound_wq, &enable_ptr_key_work);
+}
+
+static struct random_ready_callback random_ready = {
+ .func = fill_random_ptr_key
+};
+
+static int __init initialize_ptr_random(void)
+{
+ int key_size = sizeof(ptr_key);
+ int ret;
+
+ /* Use hw RNG if available. */
+ if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
+ static_branch_disable(&not_filled_random_ptr_key);
+ return 0;
+ }
+
+ ret = add_random_ready_callback(&random_ready);
+ if (!ret) {
+ return 0;
+ } else if (ret == -EALREADY) {
+ /* This is in preemptible context */
+ enable_ptr_key_workfn(&enable_ptr_key_work);
+ return 0;
+ }
+
+ return ret;
+}
+early_initcall(initialize_ptr_random);
+
+/* Maps a pointer to a 32 bit unique identifier. */
+static char *ptr_to_id(char *buf, char *end, const void *ptr,
+ struct printf_spec spec)
+{
+ const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
+ unsigned long hashval;
+
+ /* When debugging early boot use non-cryptographically secure hash. */
+ if (unlikely(debug_boot_weak_hash)) {
+ hashval = hash_long((unsigned long)ptr, 32);
+ return pointer_string(buf, end, (const void *)hashval, spec);
+ }
+
+ if (static_branch_unlikely(&not_filled_random_ptr_key)) {
+ spec.field_width = 2 * sizeof(ptr);
+ /* string length must be less than default_width */
+ return string(buf, end, str, spec);
+ }
+
+#ifdef CONFIG_64BIT
+ hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
+ /*
+ * Mask off the first 32 bits, this makes explicit that we have
+ * modified the address (and 32 bits is plenty for a unique ID).
+ */
+ hashval = hashval & 0xffffffff;
+#else
+ hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
+#endif
+ return pointer_string(buf, end, (const void *)hashval, spec);
+}
+
+static noinline_for_stack
char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
const char *fmt)
{
@@ -1357,20 +1460,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
return string(buf, end, uuid, spec);
}
-static noinline_for_stack
-char *pointer_string(char *buf, char *end, const void *ptr,
- struct printf_spec spec)
-{
- spec.base = 16;
- spec.flags |= SMALL;
- if (spec.field_width == -1) {
- spec.field_width = 2 * sizeof(ptr);
- spec.flags |= ZEROPAD;
- }
-
- return number(buf, end, (unsigned long int)ptr, spec);
-}
-
int kptr_restrict __read_mostly;
static noinline_for_stack
@@ -1421,7 +1510,8 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
}
static noinline_for_stack
-char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
+char *netdev_bits(char *buf, char *end, const void *addr,
+ struct printf_spec spec, const char *fmt)
{
unsigned long long num;
int size;
@@ -1432,9 +1522,7 @@ char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
size = sizeof(netdev_features_t);
break;
default:
- num = (unsigned long)addr;
- size = sizeof(unsigned long);
- break;
+ return ptr_to_id(buf, end, addr, spec);
}
return special_hex_number(buf, end, num, size);
@@ -1474,7 +1562,7 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
#ifdef CONFIG_COMMON_CLK
return string(buf, end, __clk_get_name(clk), spec);
#else
- return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
+ return ptr_to_id(buf, end, clk, spec);
#endif
}
}
@@ -1651,94 +1739,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
return widen_string(buf, buf - buf_start, end, spec);
}
-/* Make pointers available for printing early in the boot sequence. */
-static int debug_boot_weak_hash __ro_after_init;
-
-static int __init debug_boot_weak_hash_enable(char *str)
-{
- debug_boot_weak_hash = 1;
- pr_info("debug_boot_weak_hash enabled\n");
- return 0;
-}
-early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
-
-static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
-static siphash_key_t ptr_key __read_mostly;
-
-static void enable_ptr_key_workfn(struct work_struct *work)
-{
- get_random_bytes(&ptr_key, sizeof(ptr_key));
- /* Needs to run from preemptible context */
- static_branch_disable(&not_filled_random_ptr_key);
-}
-
-static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
-
-static void fill_random_ptr_key(struct random_ready_callback *unused)
-{
- /* This may be in an interrupt handler. */
- queue_work(system_unbound_wq, &enable_ptr_key_work);
-}
-
-static struct random_ready_callback random_ready = {
- .func = fill_random_ptr_key
-};
-
-static int __init initialize_ptr_random(void)
-{
- int key_size = sizeof(ptr_key);
- int ret;
-
- /* Use hw RNG if available. */
- if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
- static_branch_disable(&not_filled_random_ptr_key);
- return 0;
- }
-
- ret = add_random_ready_callback(&random_ready);
- if (!ret) {
- return 0;
- } else if (ret == -EALREADY) {
- /* This is in preemptible context */
- enable_ptr_key_workfn(&enable_ptr_key_work);
- return 0;
- }
-
- return ret;
-}
-early_initcall(initialize_ptr_random);
-
-/* Maps a pointer to a 32 bit unique identifier. */
-static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
-{
- const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
- unsigned long hashval;
-
- /* When debugging early boot use non-cryptographically secure hash. */
- if (unlikely(debug_boot_weak_hash)) {
- hashval = hash_long((unsigned long)ptr, 32);
- return pointer_string(buf, end, (const void *)hashval, spec);
- }
-
- if (static_branch_unlikely(&not_filled_random_ptr_key)) {
- spec.field_width = 2 * sizeof(ptr);
- /* string length must be less than default_width */
- return string(buf, end, str, spec);
- }
-
-#ifdef CONFIG_64BIT
- hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
- /*
- * Mask off the first 32 bits, this makes explicit that we have
- * modified the address (and 32 bits is plenty for a unique ID).
- */
- hashval = hashval & 0xffffffff;
-#else
- hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
-#endif
- return pointer_string(buf, end, (const void *)hashval, spec);
-}
-
/*
* Show a '%p' thing. A kernel extension is that the '%p' is followed
* by an extra set of alphanumeric characters that are extended format
@@ -1942,7 +1942,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
break;
return restricted_pointer(buf, end, ptr, spec);
case 'N':
- return netdev_bits(buf, end, ptr, fmt);
+ return netdev_bits(buf, end, ptr, spec, fmt);
case 'a':
return address_val(buf, end, ptr, fmt);
case 'd':