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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt14
-rw-r--r--Documentation/core-api/printk-formats.rst34
-rw-r--r--Documentation/filesystems/sysfs.txt4
-rw-r--r--Documentation/translations/zh_CN/filesystems/sysfs.txt4
4 files changed, 30 insertions, 26 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index dc63e5bddf78..90cefbddf1ed 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -646,6 +646,20 @@
console=brl,ttyS0
For now, only VisioBraille is supported.
+ console_msg_format=
+ [KNL] Change console messages format
+ default
+ By default we print messages on consoles in
+ "[time stamp] text\n" format (time stamp may not be
+ printed, depending on CONFIG_PRINTK_TIME or
+ `printk_time' param).
+ syslog
+ Switch to syslog format: "<%u>[time stamp] text\n"
+ IOW, each message will have a facility and loglevel
+ prefix. The format is similar to one used by syslog()
+ syscall, or to executing "dmesg -S --raw" or to reading
+ from /proc/kmsg.
+
consoleblank= [KNL] The console blank (screen saver) timeout in
seconds. A value of 0 disables the blank timer.
Defaults to 0.
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index 258b46435320..934559b3c130 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -68,42 +68,32 @@ Symbols/Function Pointers
::
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
%pF versatile_init+0x0/0x110
%pf versatile_init
- %pS versatile_init+0x0/0x110
%pSR versatile_init+0x9/0x110
(with __builtin_extract_return_addr() translation)
- %ps versatile_init
%pB prev_fn_of_versatile_init+0x88/0x88
-The ``F`` and ``f`` specifiers are for printing function pointers,
-for example, f->func, &gettimeofday. They have the same result as
-``S`` and ``s`` specifiers. But they do an extra conversion on
-ia64, ppc64 and parisc64 architectures where the function pointers
-are actually function descriptors.
+The ``S`` and ``s`` specifiers are used for printing a pointer in symbolic
+format. They result in the symbol name with (S) or without (s)
+offsets. If KALLSYMS are disabled then the symbol address is printed instead.
-The ``S`` and ``s`` specifiers can be used for printing symbols
-from direct addresses, for example, __builtin_return_address(0),
-(void *)regs->ip. They result in the symbol name with (S) or
-without (s) offsets. If KALLSYMS are disabled then the symbol
-address is printed instead.
+Note, that the ``F`` and ``f`` specifiers are identical to ``S`` (``s``)
+and thus deprecated. We have ``F`` and ``f`` because on ia64, ppc64 and
+parisc64 function pointers are indirect and, in fact, are function
+descriptors, which require additional dereferencing before we can lookup
+the symbol. As of now, ``S`` and ``s`` perform dereferencing on those
+platforms (when needed), so ``F`` and ``f`` exist for compatibility
+reasons only.
The ``B`` specifier results in the symbol name with offsets and should be
used when printing stack backtraces. The specifier takes into
consideration the effect of compiler optimisations which may occur
when tail-calls are used and marked with the noreturn GCC attribute.
-Examples::
-
- printk("Going to call: %pF\n", gettimeofday);
- printk("Going to call: %pF\n", p->func);
- printk("%s: called from %pS\n", __func__, (void *)_RET_IP_);
- printk("%s: called from %pS\n", __func__,
- (void *)__builtin_return_address(0));
- printk("Faulted at %pS\n", (void *)regs->ip);
- printk(" %s%pB\n", (reliable ? "" : "? "), (void *)*stack);
-
Kernel Pointers
---------------
diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt
index 9a3658cc399e..a1426cabcef1 100644
--- a/Documentation/filesystems/sysfs.txt
+++ b/Documentation/filesystems/sysfs.txt
@@ -154,8 +154,8 @@ static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
if (dev_attr->show)
ret = dev_attr->show(dev, dev_attr, buf);
if (ret >= (ssize_t)PAGE_SIZE) {
- print_symbol("dev_attr_show: %s returned bad count\n",
- (unsigned long)dev_attr->show);
+ printk("dev_attr_show: %pS returned bad count\n",
+ dev_attr->show);
}
return ret;
}
diff --git a/Documentation/translations/zh_CN/filesystems/sysfs.txt b/Documentation/translations/zh_CN/filesystems/sysfs.txt
index 7d3b05edb8ce..452271dda141 100644
--- a/Documentation/translations/zh_CN/filesystems/sysfs.txt
+++ b/Documentation/translations/zh_CN/filesystems/sysfs.txt
@@ -167,8 +167,8 @@ static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
if (dev_attr->show)
ret = dev_attr->show(dev, dev_attr, buf);
if (ret >= (ssize_t)PAGE_SIZE) {
- print_symbol("dev_attr_show: %s returned bad count\n",
- (unsigned long)dev_attr->show);
+ printk("dev_attr_show: %pS returned bad count\n",
+ dev_attr->show);
}
return ret;
}