2017-05-16 19:27:11 -06:00
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=========================================
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How to get printk format specifiers right
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=========================================
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:Author: Randy Dunlap <rdunlap@infradead.org>
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:Author: Andrew Murray <amurray@mpc-data.co.uk>
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2017-12-19 14:17:15 -07:00
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2017-05-16 19:27:11 -06:00
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Integer types
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=============
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::
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If variable is of Type, use printk format specifier:
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------------------------------------------------------------
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2019-09-06 15:11:51 -06:00
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char %d or %x
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unsigned char %u or %x
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short int %d or %x
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unsigned short int %u or %x
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2008-11-12 14:26:55 -07:00
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int %d or %x
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unsigned int %u or %x
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long %ld or %lx
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unsigned long %lu or %lx
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long long %lld or %llx
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unsigned long long %llu or %llx
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size_t %zu or %zx
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ssize_t %zd or %zx
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2019-09-06 15:11:51 -06:00
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s8 %d or %x
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u8 %u or %x
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s16 %d or %x
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u16 %u or %x
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2015-04-15 17:17:17 -06:00
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s32 %d or %x
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u32 %u or %x
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s64 %lld or %llx
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u64 %llu or %llx
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2017-12-19 14:17:15 -07:00
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If <type> is dependent on a config option for its size (e.g., sector_t,
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blkcnt_t) or is architecture-dependent for its size (e.g., tcflag_t), use a
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format specifier of its largest possible type and explicitly cast to it.
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2017-05-16 19:27:11 -06:00
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Example::
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2015-04-15 17:17:17 -06:00
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printk("test: sector number/total blocks: %llu/%llu\n",
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(unsigned long long)sector, (unsigned long long)blockcount);
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2017-12-19 14:17:15 -07:00
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Reminder: sizeof() returns type size_t.
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2015-04-15 17:17:17 -06:00
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2017-12-19 14:17:15 -07:00
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The kernel's printf does not support %n. Floating point formats (%e, %f,
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%g, %a) are also not recognized, for obvious reasons. Use of any
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2015-11-06 17:30:35 -07:00
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unsupported specifier or length qualifier results in a WARN and early
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2017-12-19 14:17:15 -07:00
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return from vsnprintf().
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2011-06-15 13:57:09 -06:00
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2017-12-19 14:17:15 -07:00
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Pointer types
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2017-10-31 22:32:23 -06:00
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=============
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2017-12-19 14:17:15 -07:00
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A raw pointer value may be printed with %p which will hash the address
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before printing. The kernel also supports extended specifiers for printing
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pointers of different types.
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vsprintf: Prevent crash when dereferencing invalid pointers
We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).
Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.
This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.
Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:
+ (null) when accessing data on pure pure NULL address
+ (efault) when accessing data on an invalid address
It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.
Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.
Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-17 05:53:48 -06:00
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Some of the extended specifiers print the data on the given address instead
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of printing the address itself. In this case, the following error messages
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might be printed instead of the unreachable information::
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(null) data on plain NULL address
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(efault) data on invalid address
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2019-04-17 05:53:49 -06:00
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(einval) invalid data on a valid address
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vsprintf: Prevent crash when dereferencing invalid pointers
We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).
Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.
This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.
Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:
+ (null) when accessing data on pure pure NULL address
+ (efault) when accessing data on an invalid address
It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.
Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.
Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-17 05:53:48 -06:00
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2017-12-19 14:17:15 -07:00
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Plain Pointers
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--------------
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2017-10-31 22:32:23 -06:00
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::
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%p abcdef12 or 00000000abcdef12
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2017-12-19 14:17:15 -07:00
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Pointers printed without a specifier extension (i.e unadorned %p) are
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hashed to prevent leaking information about the kernel memory layout. This
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has the added benefit of providing a unique identifier. On 64-bit machines
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2018-03-21 23:23:36 -06:00
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the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it
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gathers enough entropy. If you *really* want the address see %px below.
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2017-12-19 14:17:15 -07:00
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printf: add support for printing symbolic error names
It has been suggested several times to extend vsnprintf() to be able
to convert the numeric value of ENOSPC to print "ENOSPC". This
implements that as a %p extension: With %pe, one can do
if (IS_ERR(foo)) {
pr_err("Sorry, can't do that: %pe\n", foo);
return PTR_ERR(foo);
}
instead of what is seen in quite a few places in the kernel:
if (IS_ERR(foo)) {
pr_err("Sorry, can't do that: %ld\n", PTR_ERR(foo));
return PTR_ERR(foo);
}
If the value passed to %pe is an ERR_PTR, but the library function
errname() added here doesn't know about the value, the value is simply
printed in decimal. If the value passed to %pe is not an ERR_PTR, we
treat it as an ordinary %p and thus print the hashed value (passing
non-ERR_PTR values to %pe indicates a bug in the caller, but we can't
do much about that).
With my embedded hat on, and because it's not very invasive to do,
I've made it possible to remove this. The errname() function and
associated lookup tables take up about 3K. For most, that's probably
quite acceptable and a price worth paying for more readable
dmesg (once this starts getting used), while for those that disable
printk() it's of very little use - I don't see a
procfs/sysfs/seq_printf() file reasonably making use of this - and
they clearly want to squeeze vmlinux as much as possible. Hence the
default y if PRINTK.
The symbols to include have been found by massaging the output of
find arch include -iname 'errno*.h' | xargs grep -E 'define\s*E'
In the cases where some common aliasing exists
(e.g. EAGAIN=EWOULDBLOCK on all platforms, EDEADLOCK=EDEADLK on most),
I've moved the more popular one (in terms of 'git grep -w Efoo | wc)
to the bottom so that one takes precedence.
Link: http://lkml.kernel.org/r/20191015190706.15989-1-linux@rasmusvillemoes.dk
To: "Jonathan Corbet" <corbet@lwn.net>
To: linux-kernel@vger.kernel.org
Cc: "Andy Shevchenko" <andy.shevchenko@gmail.com>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: "Joe Perches" <joe@perches.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
[andy.shevchenko@gmail.com: use abs()]
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-15 13:07:05 -06:00
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Error Pointers
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--------------
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::
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%pe -ENOSPC
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For printing error pointers (i.e. a pointer for which IS_ERR() is true)
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as a symbolic error name. Error values for which no symbolic name is
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known are printed in decimal, while a non-ERR_PTR passed as the
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argument to %pe gets treated as ordinary %p.
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2017-05-16 19:27:11 -06:00
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Symbols/Function Pointers
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2017-12-19 14:17:15 -07:00
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-------------------------
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2017-05-16 19:27:11 -06:00
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::
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2011-06-15 13:57:09 -06:00
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2017-12-05 21:36:49 -07:00
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%pS versatile_init+0x0/0x110
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%ps versatile_init
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2012-12-12 11:18:50 -07:00
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%pSR versatile_init+0x9/0x110
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(with __builtin_extract_return_addr() translation)
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2011-06-15 13:57:09 -06:00
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%pB prev_fn_of_versatile_init+0x88/0x88
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2017-12-19 14:17:15 -07:00
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2017-12-05 21:36:49 -07:00
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The ``S`` and ``s`` specifiers are used for printing a pointer in symbolic
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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:
- Add a console_msg_format command line option:
The value "default" keeps the old "[time stamp] text\n" format. The
value "syslog" allows to see the syslog-like "<log
level>[timestamp] text" format.
This feature was requested by people doing regression tests, for
example, 0day robot. They want to have both filtered and full logs
at hands.
- Reduce the risk of softlockup:
Pass the console owner in a busy loop.
This is a new approach to the old problem. It was first proposed by
Steven Rostedt on Kernel Summit 2017. It marks a context in which
the console_lock owner calls console drivers and could not sleep.
On the other side, printk() callers could detect this state and use
a busy wait instead of a simple console_trylock(). Finally, the
console_lock owner checks if there is a busy waiter at the end of
the special context and eventually passes the console_lock to the
waiter.
The hand-off works surprisingly well and helps in many situations.
Well, there is still a possibility of the softlockup, for example,
when the flood of messages stops and the last owner still has too
much to flush.
There is increasing number of people having problems with
printk-related softlockups. We might eventually need to get better
solution. Anyway, this looks like a good start and promising
direction.
- Do not allow to schedule in console_unlock() called from printk():
This reverts an older controversial commit. The reschedule helped
to avoid softlockups. But it also slowed down the console output.
This patch is obsoleted by the new console waiter logic described
above. In fact, the reschedule made the hand-off less effective.
- Deprecate "%pf" and "%pF" format specifier:
It was needed on ia64, ppc64 and parisc64 to dereference function
descriptors and show the real function address. It is done
transparently by "%ps" and "pS" format specifier now.
Sergey Senozhatsky found that all the function descriptors were in
a special elf section and could be easily detected.
- Remove printk_symbol() API:
It has been obsoleted by "%pS" format specifier, and this change
helped to remove few continuous lines and a less intuitive old API.
- Remove redundant memsets:
Sergey removed unnecessary memset when processing printk.devkmsg
command line option.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
printk: drop redundant devkmsg_log_str memsets
printk: Never set console_may_schedule in console_trylock()
printk: Hide console waiter logic into helpers
printk: Add console owner and waiter logic to load balance console writes
kallsyms: remove print_symbol() function
checkpatch: add pF/pf deprecation warning
symbol lookup: introduce dereference_symbol_descriptor()
parisc64: Add .opd based function descriptor dereference
powerpc64: Add .opd based function descriptor dereference
ia64: Add .opd based function descriptor dereference
sections: split dereference_function_descriptor()
openrisc: Fix conflicting types for _exext and _stext
lib: do not use print_symbol()
irq debug: do not use print_symbol()
sysfs: do not use print_symbol()
drivers: do not use print_symbol()
x86: do not use print_symbol()
unicore32: do not use print_symbol()
sh: do not use print_symbol()
mn10300: do not use print_symbol()
...
2018-02-01 14:36:15 -07:00
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format. They result in the symbol name with (S) or without (s)
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2017-12-05 21:36:49 -07:00
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offsets. If KALLSYMS are disabled then the symbol address is printed instead.
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2017-08-15 03:34:19 -06:00
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2017-05-16 19:27:11 -06:00
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The ``B`` specifier results in the symbol name with offsets and should be
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used when printing stack backtraces. The specifier takes into
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consideration the effect of compiler optimisations which may occur
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2017-12-19 14:17:15 -07:00
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when tail-calls are used and marked with the noreturn GCC attribute.
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2011-06-15 13:57:09 -06:00
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2017-05-16 19:27:11 -06:00
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Kernel Pointers
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2017-12-19 14:17:15 -07:00
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---------------
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2011-06-15 13:57:09 -06:00
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2017-05-16 19:27:11 -06:00
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::
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2011-06-15 13:57:09 -06:00
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2017-11-22 16:55:24 -07:00
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%pK 01234567 or 0123456789abcdef
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2011-06-15 13:57:09 -06:00
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2017-05-16 19:27:11 -06:00
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For printing kernel pointers which should be hidden from unprivileged
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2017-12-19 14:17:15 -07:00
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users. The behaviour of %pK depends on the kptr_restrict sysctl - see
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2019-04-22 13:48:00 -06:00
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Documentation/admin-guide/sysctl/kernel.rst for more details.
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2017-05-16 19:27:11 -06:00
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2017-11-22 16:59:45 -07:00
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Unmodified Addresses
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--------------------
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2017-11-22 16:59:45 -07:00
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::
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%px 01234567 or 0123456789abcdef
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2017-12-19 14:17:15 -07:00
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For printing pointers when you *really* want to print the address. Please
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2017-11-22 16:59:45 -07:00
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consider whether or not you are leaking sensitive information about the
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2017-12-19 14:17:15 -07:00
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kernel memory layout before printing pointers with %px. %px is functionally
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equivalent to %lx (or %lu). %px is preferred because it is more uniquely
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grep'able. If in the future we need to modify the way the kernel handles
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printing pointers we will be better equipped to find the call sites.
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2017-11-22 16:59:45 -07:00
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2019-10-01 04:04:49 -06:00
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Pointer Differences
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-------------------
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::
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%td 2560
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%tx a00
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For printing the pointer differences, use the %t modifier for ptrdiff_t.
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Example::
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printk("test: difference between pointers: %td\n", ptr2 - ptr1);
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2017-05-16 19:27:11 -06:00
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Struct Resources
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2017-12-19 14:17:15 -07:00
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----------------
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2011-06-15 13:57:09 -06:00
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2017-05-16 19:27:11 -06:00
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::
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2011-06-15 13:57:09 -06:00
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%pr [mem 0x60000000-0x6fffffff flags 0x2200] or
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[mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
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%pR [mem 0x60000000-0x6fffffff pref] or
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[mem 0x0000000060000000-0x000000006fffffff pref]
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2017-05-16 19:27:11 -06:00
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For printing struct resources. The ``R`` and ``r`` specifiers result in a
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2017-12-19 14:17:15 -07:00
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printed resource with (R) or without (r) a decoded flags member.
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2017-05-16 19:27:11 -06:00
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Passed by reference.
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2017-12-19 14:17:15 -07:00
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Physical address types phys_addr_t
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----------------------------------
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2011-06-15 13:57:09 -06:00
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2017-05-16 19:27:11 -06:00
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::
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2013-02-21 17:43:09 -07:00
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2014-01-23 16:54:17 -07:00
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%pa[p] 0x01234567 or 0x0123456789abcdef
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2013-02-21 17:43:09 -07:00
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2017-12-19 14:17:15 -07:00
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For printing a phys_addr_t type (and its derivatives, such as
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resource_size_t) which can vary based on build options, regardless of the
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width of the CPU data path.
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Passed by reference.
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2013-02-21 17:43:09 -07:00
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2017-12-19 14:17:15 -07:00
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DMA address types dma_addr_t
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----------------------------
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2017-05-16 19:27:11 -06:00
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::
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2014-01-23 16:54:17 -07:00
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%pad 0x01234567 or 0x0123456789abcdef
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
For printing a dma_addr_t type which can vary based on build options,
|
|
|
|
regardless of the width of the CPU data path.
|
|
|
|
|
|
|
|
Passed by reference.
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
Raw buffer as an escaped string
|
2017-12-19 14:17:15 -07:00
|
|
|
-------------------------------
|
2014-01-23 16:54:17 -07:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
::
|
2014-10-13 16:55:18 -06:00
|
|
|
|
|
|
|
%*pE[achnops]
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing raw buffer as an escaped string. For the following buffer::
|
2014-10-13 16:55:18 -06:00
|
|
|
|
|
|
|
1b 62 20 5c 43 07 22 90 0d 5d
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
A few examples show how the conversion would be done (excluding surrounding
|
|
|
|
quotes)::
|
2014-10-13 16:55:18 -06:00
|
|
|
|
|
|
|
%*pE "\eb \C\a"\220\r]"
|
|
|
|
%*pEhp "\x1bb \C\x07"\x90\x0d]"
|
|
|
|
%*pEa "\e\142\040\\\103\a\042\220\r\135"
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
The conversion rules are applied according to an optional combination
|
|
|
|
of flags (see :c:func:`string_escape_mem` kernel documentation for the
|
|
|
|
details):
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
- a - ESCAPE_ANY
|
|
|
|
- c - ESCAPE_SPECIAL
|
|
|
|
- h - ESCAPE_HEX
|
|
|
|
- n - ESCAPE_NULL
|
|
|
|
- o - ESCAPE_OCTAL
|
|
|
|
- p - ESCAPE_NP
|
|
|
|
- s - ESCAPE_SPACE
|
2014-10-13 16:55:18 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
By default ESCAPE_ANY_NP is used.
|
2014-10-13 16:55:18 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
ESCAPE_ANY_NP is the sane choice for many cases, in particularly for
|
|
|
|
printing SSIDs.
|
2014-10-13 16:55:18 -06:00
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
If field width is omitted then 1 byte only will be escaped.
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
Raw buffer as a hex string
|
2017-12-19 14:17:15 -07:00
|
|
|
--------------------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2015-11-06 17:30:17 -07:00
|
|
|
|
2012-07-30 15:40:27 -06:00
|
|
|
%*ph 00 01 02 ... 3f
|
|
|
|
%*phC 00:01:02: ... :3f
|
|
|
|
%*phD 00-01-02- ... -3f
|
|
|
|
%*phN 000102 ... 3f
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
For printing small buffers (up to 64 bytes long) as a hex string with a
|
|
|
|
certain separator. For larger buffers consider using
|
2017-05-16 19:27:11 -06:00
|
|
|
:c:func:`print_hex_dump`.
|
|
|
|
|
|
|
|
MAC/FDDI addresses
|
2017-12-19 14:17:15 -07:00
|
|
|
------------------
|
2012-07-30 15:40:27 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
::
|
2011-06-15 13:57:09 -06:00
|
|
|
|
|
|
|
%pM 00:01:02:03:04:05
|
2012-07-30 15:40:23 -06:00
|
|
|
%pMR 05:04:03:02:01:00
|
2011-06-15 13:57:09 -06:00
|
|
|
%pMF 00-01-02-03-04-05
|
|
|
|
%pm 000102030405
|
2012-10-04 18:12:33 -06:00
|
|
|
%pmR 050403020100
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing 6-byte MAC/FDDI addresses in hex notation. The ``M`` and ``m``
|
2017-12-19 14:17:15 -07:00
|
|
|
specifiers result in a printed address with (M) or without (m) byte
|
|
|
|
separators. The default byte separator is the colon (:).
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Where FDDI addresses are concerned the ``F`` specifier can be used after
|
2017-12-19 14:17:15 -07:00
|
|
|
the ``M`` specifier to use dash (-) separators instead of the default
|
2017-05-16 19:27:11 -06:00
|
|
|
separator.
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For Bluetooth addresses the ``R`` specifier shall be used after the ``M``
|
|
|
|
specifier to use reversed byte order suitable for visual interpretation
|
|
|
|
of Bluetooth addresses which are in the little endian order.
|
2012-07-30 15:40:23 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
|
|
|
|
|
|
|
IPv4 addresses
|
2017-12-19 14:17:15 -07:00
|
|
|
--------------
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
::
|
2011-06-15 13:57:09 -06:00
|
|
|
|
|
|
|
%pI4 1.2.3.4
|
|
|
|
%pi4 001.002.003.004
|
2013-06-28 07:49:39 -06:00
|
|
|
%p[Ii]4[hnbl]
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing IPv4 dot-separated decimal addresses. The ``I4`` and ``i4``
|
2017-12-19 14:17:15 -07:00
|
|
|
specifiers result in a printed address with (i4) or without (I4) leading
|
|
|
|
zeros.
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
The additional ``h``, ``n``, ``b``, and ``l`` specifiers are used to specify
|
|
|
|
host, network, big or little endian order addresses respectively. Where
|
|
|
|
no specifier is provided the default network/big endian order is used.
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
IPv6 addresses
|
2017-12-19 14:17:15 -07:00
|
|
|
--------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2011-06-15 13:57:09 -06:00
|
|
|
|
|
|
|
%pI6 0001:0002:0003:0004:0005:0006:0007:0008
|
|
|
|
%pi6 00010002000300040005000600070008
|
|
|
|
%pI6c 1:2:3:4:5:6:7:8
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing IPv6 network-order 16-bit hex addresses. The ``I6`` and ``i6``
|
2017-12-19 14:17:15 -07:00
|
|
|
specifiers result in a printed address with (I6) or without (i6)
|
2017-05-16 19:27:11 -06:00
|
|
|
colon-separators. Leading zeros are always used.
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
The additional ``c`` specifier can be used with the ``I`` specifier to
|
|
|
|
print a compressed IPv6 address as described by
|
|
|
|
http://tools.ietf.org/html/rfc5952
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
IPv4/IPv6 addresses (generic, with port, flowinfo, scope)
|
2017-12-19 14:17:15 -07:00
|
|
|
---------------------------------------------------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier
In order to avoid making code that deals with printing both, IPv4 and
IPv6 addresses, unnecessary complicated as for example ...
if (sa.sa_family == AF_INET6)
printk("... %pI6 ...", ..sin6_addr);
else
printk("... %pI4 ...", ..sin_addr.s_addr);
... it would be better to introduce a format specifier that can deal
with those kind of situations internally; just as we have a "struct
sockaddr" for generic mapping into "struct sockaddr_in" or "struct
sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could
reduce the above statement into something like:
printk("... %pIS ..", &sockaddr);
In case our pointer is NULL, pointer() then deals with that already at
an earlier point in time internally. While we're at it, support for both
%piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free.
Additionally to that, postfix specifiers 'p', 'f' and 's' are supported
as suggested and initially implemented in 2009 by Joe Perches [1].
Handling of those additional specifiers orientate on the initial RFC that
was proposed. Also we support IPv6 compressed format specified by 'c' and
various other IPv4 extensions as stated in the documentation part.
Likely, there are many other areas than just SCTP in the kernel to make
use of this extension as well.
[1] http://patchwork.ozlabs.org/patch/31480/
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Joe Perches <joe@perches.com>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 11:49:39 -06:00
|
|
|
|
|
|
|
%pIS 1.2.3.4 or 0001:0002:0003:0004:0005:0006:0007:0008
|
|
|
|
%piS 001.002.003.004 or 00010002000300040005000600070008
|
|
|
|
%pISc 1.2.3.4 or 1:2:3:4:5:6:7:8
|
|
|
|
%pISpc 1.2.3.4:12345 or [1:2:3:4:5:6:7:8]:12345
|
|
|
|
%p[Ii]S[pfschnbl]
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
For printing an IP address without the need to distinguish whether it's of
|
|
|
|
type AF_INET or AF_INET6. A pointer to a valid struct sockaddr,
|
2017-05-16 19:27:11 -06:00
|
|
|
specified through ``IS`` or ``iS``, can be passed to this format specifier.
|
lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier
In order to avoid making code that deals with printing both, IPv4 and
IPv6 addresses, unnecessary complicated as for example ...
if (sa.sa_family == AF_INET6)
printk("... %pI6 ...", ..sin6_addr);
else
printk("... %pI4 ...", ..sin_addr.s_addr);
... it would be better to introduce a format specifier that can deal
with those kind of situations internally; just as we have a "struct
sockaddr" for generic mapping into "struct sockaddr_in" or "struct
sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could
reduce the above statement into something like:
printk("... %pIS ..", &sockaddr);
In case our pointer is NULL, pointer() then deals with that already at
an earlier point in time internally. While we're at it, support for both
%piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free.
Additionally to that, postfix specifiers 'p', 'f' and 's' are supported
as suggested and initially implemented in 2009 by Joe Perches [1].
Handling of those additional specifiers orientate on the initial RFC that
was proposed. Also we support IPv6 compressed format specified by 'c' and
various other IPv4 extensions as stated in the documentation part.
Likely, there are many other areas than just SCTP in the kernel to make
use of this extension as well.
[1] http://patchwork.ozlabs.org/patch/31480/
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Joe Perches <joe@perches.com>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 11:49:39 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
The additional ``p``, ``f``, and ``s`` specifiers are used to specify port
|
|
|
|
(IPv4, IPv6), flowinfo (IPv6) and scope (IPv6). Ports have a ``:`` prefix,
|
|
|
|
flowinfo a ``/`` and scope a ``%``, each followed by the actual value.
|
lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier
In order to avoid making code that deals with printing both, IPv4 and
IPv6 addresses, unnecessary complicated as for example ...
if (sa.sa_family == AF_INET6)
printk("... %pI6 ...", ..sin6_addr);
else
printk("... %pI4 ...", ..sin_addr.s_addr);
... it would be better to introduce a format specifier that can deal
with those kind of situations internally; just as we have a "struct
sockaddr" for generic mapping into "struct sockaddr_in" or "struct
sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could
reduce the above statement into something like:
printk("... %pIS ..", &sockaddr);
In case our pointer is NULL, pointer() then deals with that already at
an earlier point in time internally. While we're at it, support for both
%piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free.
Additionally to that, postfix specifiers 'p', 'f' and 's' are supported
as suggested and initially implemented in 2009 by Joe Perches [1].
Handling of those additional specifiers orientate on the initial RFC that
was proposed. Also we support IPv6 compressed format specified by 'c' and
various other IPv4 extensions as stated in the documentation part.
Likely, there are many other areas than just SCTP in the kernel to make
use of this extension as well.
[1] http://patchwork.ozlabs.org/patch/31480/
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Joe Perches <joe@perches.com>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 11:49:39 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
In case of an IPv6 address the compressed IPv6 address as described by
|
|
|
|
http://tools.ietf.org/html/rfc5952 is being used if the additional
|
|
|
|
specifier ``c`` is given. The IPv6 address is surrounded by ``[``, ``]`` in
|
|
|
|
case of additional specifiers ``p``, ``f`` or ``s`` as suggested by
|
|
|
|
https://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-07
|
lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier
In order to avoid making code that deals with printing both, IPv4 and
IPv6 addresses, unnecessary complicated as for example ...
if (sa.sa_family == AF_INET6)
printk("... %pI6 ...", ..sin6_addr);
else
printk("... %pI4 ...", ..sin_addr.s_addr);
... it would be better to introduce a format specifier that can deal
with those kind of situations internally; just as we have a "struct
sockaddr" for generic mapping into "struct sockaddr_in" or "struct
sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could
reduce the above statement into something like:
printk("... %pIS ..", &sockaddr);
In case our pointer is NULL, pointer() then deals with that already at
an earlier point in time internally. While we're at it, support for both
%piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free.
Additionally to that, postfix specifiers 'p', 'f' and 's' are supported
as suggested and initially implemented in 2009 by Joe Perches [1].
Handling of those additional specifiers orientate on the initial RFC that
was proposed. Also we support IPv6 compressed format specified by 'c' and
various other IPv4 extensions as stated in the documentation part.
Likely, there are many other areas than just SCTP in the kernel to make
use of this extension as well.
[1] http://patchwork.ozlabs.org/patch/31480/
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Joe Perches <joe@perches.com>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 11:49:39 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
In case of IPv4 addresses, the additional ``h``, ``n``, ``b``, and ``l``
|
|
|
|
specifiers can be used as well and are ignored in case of an IPv6
|
|
|
|
address.
|
lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier
In order to avoid making code that deals with printing both, IPv4 and
IPv6 addresses, unnecessary complicated as for example ...
if (sa.sa_family == AF_INET6)
printk("... %pI6 ...", ..sin6_addr);
else
printk("... %pI4 ...", ..sin_addr.s_addr);
... it would be better to introduce a format specifier that can deal
with those kind of situations internally; just as we have a "struct
sockaddr" for generic mapping into "struct sockaddr_in" or "struct
sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could
reduce the above statement into something like:
printk("... %pIS ..", &sockaddr);
In case our pointer is NULL, pointer() then deals with that already at
an earlier point in time internally. While we're at it, support for both
%piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free.
Additionally to that, postfix specifiers 'p', 'f' and 's' are supported
as suggested and initially implemented in 2009 by Joe Perches [1].
Handling of those additional specifiers orientate on the initial RFC that
was proposed. Also we support IPv6 compressed format specified by 'c' and
various other IPv4 extensions as stated in the documentation part.
Likely, there are many other areas than just SCTP in the kernel to make
use of this extension as well.
[1] http://patchwork.ozlabs.org/patch/31480/
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Joe Perches <joe@perches.com>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 11:49:39 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Further examples::
|
lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier
In order to avoid making code that deals with printing both, IPv4 and
IPv6 addresses, unnecessary complicated as for example ...
if (sa.sa_family == AF_INET6)
printk("... %pI6 ...", ..sin6_addr);
else
printk("... %pI4 ...", ..sin_addr.s_addr);
... it would be better to introduce a format specifier that can deal
with those kind of situations internally; just as we have a "struct
sockaddr" for generic mapping into "struct sockaddr_in" or "struct
sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could
reduce the above statement into something like:
printk("... %pIS ..", &sockaddr);
In case our pointer is NULL, pointer() then deals with that already at
an earlier point in time internally. While we're at it, support for both
%piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free.
Additionally to that, postfix specifiers 'p', 'f' and 's' are supported
as suggested and initially implemented in 2009 by Joe Perches [1].
Handling of those additional specifiers orientate on the initial RFC that
was proposed. Also we support IPv6 compressed format specified by 'c' and
various other IPv4 extensions as stated in the documentation part.
Likely, there are many other areas than just SCTP in the kernel to make
use of this extension as well.
[1] http://patchwork.ozlabs.org/patch/31480/
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Joe Perches <joe@perches.com>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 11:49:39 -06:00
|
|
|
|
|
|
|
%pISfc 1.2.3.4 or [1:2:3:4:5:6:7:8]/123456789
|
|
|
|
%pISsc 1.2.3.4 or [1:2:3:4:5:6:7:8]%1234567890
|
|
|
|
%pISpfc 1.2.3.4:12345 or [1:2:3:4:5:6:7:8]:12345/123456789
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
UUID/GUID addresses
|
2017-12-19 14:17:15 -07:00
|
|
|
-------------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2011-06-15 13:57:09 -06:00
|
|
|
|
|
|
|
%pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
|
|
|
|
%pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
|
|
|
|
%pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
|
|
|
|
%pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
For printing 16-byte UUID/GUIDs addresses. The additional ``l``, ``L``,
|
|
|
|
``b`` and ``B`` specifiers are used to specify a little endian order in
|
|
|
|
lower (l) or upper case (L) hex notation - and big endian order in lower (b)
|
|
|
|
or upper case (B) hex notation.
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Where no additional specifiers are used the default big endian
|
2017-12-19 14:17:15 -07:00
|
|
|
order with lower case hex notation will be printed.
|
2011-06-15 13:57:09 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
|
|
|
|
|
|
|
dentry names
|
2017-12-19 14:17:15 -07:00
|
|
|
------------
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
::
|
2015-11-06 17:30:17 -07:00
|
|
|
|
2013-09-03 10:00:44 -06:00
|
|
|
%pd{,2,3,4}
|
|
|
|
%pD{,2,3,4}
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
For printing dentry name; if we race with :c:func:`d_move`, the name might
|
|
|
|
be a mix of old and new ones, but it won't oops. %pd dentry is a safer
|
|
|
|
equivalent of %s dentry->d_name.name we used to use, %pd<n> prints ``n``
|
|
|
|
last components. %pD does the same thing for struct file.
|
2013-09-03 10:00:44 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
block_device names
|
2017-12-19 14:17:15 -07:00
|
|
|
------------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2015-04-13 06:31:35 -06:00
|
|
|
|
|
|
|
%pg sda, sda1 or loop0p1
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing name of block_device pointers.
|
|
|
|
|
|
|
|
struct va_format
|
2017-12-19 14:17:15 -07:00
|
|
|
----------------
|
2015-04-13 06:31:35 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
::
|
2011-06-15 13:57:09 -06:00
|
|
|
|
|
|
|
%pV
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing struct va_format structures. These contain a format string
|
|
|
|
and va_list as follows::
|
2011-06-15 13:57:09 -06:00
|
|
|
|
|
|
|
struct va_format {
|
|
|
|
const char *fmt;
|
|
|
|
va_list *va;
|
|
|
|
};
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Implements a "recursive vsnprintf".
|
2015-11-06 17:30:17 -07:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Do not use this feature without some mechanism to verify the
|
|
|
|
correctness of the format string and va_list arguments.
|
2008-11-12 14:26:55 -07:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
|
|
|
|
2018-10-08 05:08:48 -06:00
|
|
|
Device tree nodes
|
|
|
|
-----------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2015-04-15 17:17:14 -06:00
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
%pOF[fnpPcCF]
|
vsprintf: Add %p extension "%pOF" for device tree
90% of the usage of device node's full_name is printing it out in a
kernel message. However, storing the full path for every node is
wasteful and redundant. With a custom format specifier, we can generate
the full path at run-time and eventually remove the full path from every
node.
For instance typical use is:
pr_info("Frobbing node %s\n", node->full_name);
Which can be written now as:
pr_info("Frobbing node %pOF\n", node);
'%pO' is the base specifier to represent kobjects with '%pOF'
representing struct device_node. Currently, struct device_node is the
only supported type of kobject.
More fine-grained control of formatting includes printing the name,
flags, path-spec name and others, explained in the documentation entry.
Originally written by Pantelis, but pretty much rewrote the core
function using existing string/number functions. The 2 passes were
unnecessary and have been removed. Also, updated the checkpatch.pl
check. The unittest code was written by Grant Likely.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2015-01-21 10:06:14 -07:00
|
|
|
|
|
|
|
|
2018-10-08 05:08:48 -06:00
|
|
|
For printing device tree node structures. Default behaviour is
|
2017-12-19 14:17:15 -07:00
|
|
|
equivalent to %pOFf.
|
vsprintf: Add %p extension "%pOF" for device tree
90% of the usage of device node's full_name is printing it out in a
kernel message. However, storing the full path for every node is
wasteful and redundant. With a custom format specifier, we can generate
the full path at run-time and eventually remove the full path from every
node.
For instance typical use is:
pr_info("Frobbing node %s\n", node->full_name);
Which can be written now as:
pr_info("Frobbing node %pOF\n", node);
'%pO' is the base specifier to represent kobjects with '%pOF'
representing struct device_node. Currently, struct device_node is the
only supported type of kobject.
More fine-grained control of formatting includes printing the name,
flags, path-spec name and others, explained in the documentation entry.
Originally written by Pantelis, but pretty much rewrote the core
function using existing string/number functions. The 2 passes were
unnecessary and have been removed. Also, updated the checkpatch.pl
check. The unittest code was written by Grant Likely.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2015-01-21 10:06:14 -07:00
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
- f - device node full_name
|
|
|
|
- n - device node name
|
|
|
|
- p - device node phandle
|
|
|
|
- P - device node path spec (name + @unit)
|
|
|
|
- F - device node flags
|
|
|
|
- c - major compatible string
|
|
|
|
- C - full compatible string
|
vsprintf: Add %p extension "%pOF" for device tree
90% of the usage of device node's full_name is printing it out in a
kernel message. However, storing the full path for every node is
wasteful and redundant. With a custom format specifier, we can generate
the full path at run-time and eventually remove the full path from every
node.
For instance typical use is:
pr_info("Frobbing node %s\n", node->full_name);
Which can be written now as:
pr_info("Frobbing node %pOF\n", node);
'%pO' is the base specifier to represent kobjects with '%pOF'
representing struct device_node. Currently, struct device_node is the
only supported type of kobject.
More fine-grained control of formatting includes printing the name,
flags, path-spec name and others, explained in the documentation entry.
Originally written by Pantelis, but pretty much rewrote the core
function using existing string/number functions. The 2 passes were
unnecessary and have been removed. Also, updated the checkpatch.pl
check. The unittest code was written by Grant Likely.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2015-01-21 10:06:14 -07:00
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
The separator when using multiple arguments is ':'
|
vsprintf: Add %p extension "%pOF" for device tree
90% of the usage of device node's full_name is printing it out in a
kernel message. However, storing the full path for every node is
wasteful and redundant. With a custom format specifier, we can generate
the full path at run-time and eventually remove the full path from every
node.
For instance typical use is:
pr_info("Frobbing node %s\n", node->full_name);
Which can be written now as:
pr_info("Frobbing node %pOF\n", node);
'%pO' is the base specifier to represent kobjects with '%pOF'
representing struct device_node. Currently, struct device_node is the
only supported type of kobject.
More fine-grained control of formatting includes printing the name,
flags, path-spec name and others, explained in the documentation entry.
Originally written by Pantelis, but pretty much rewrote the core
function using existing string/number functions. The 2 passes were
unnecessary and have been removed. Also, updated the checkpatch.pl
check. The unittest code was written by Grant Likely.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2015-01-21 10:06:14 -07:00
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
Examples::
|
vsprintf: Add %p extension "%pOF" for device tree
90% of the usage of device node's full_name is printing it out in a
kernel message. However, storing the full path for every node is
wasteful and redundant. With a custom format specifier, we can generate
the full path at run-time and eventually remove the full path from every
node.
For instance typical use is:
pr_info("Frobbing node %s\n", node->full_name);
Which can be written now as:
pr_info("Frobbing node %pOF\n", node);
'%pO' is the base specifier to represent kobjects with '%pOF'
representing struct device_node. Currently, struct device_node is the
only supported type of kobject.
More fine-grained control of formatting includes printing the name,
flags, path-spec name and others, explained in the documentation entry.
Originally written by Pantelis, but pretty much rewrote the core
function using existing string/number functions. The 2 passes were
unnecessary and have been removed. Also, updated the checkpatch.pl
check. The unittest code was written by Grant Likely.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2015-01-21 10:06:14 -07:00
|
|
|
|
|
|
|
%pOF /foo/bar@0 - Node full name
|
|
|
|
%pOFf /foo/bar@0 - Same as above
|
|
|
|
%pOFfp /foo/bar@0:10 - Node full name + phandle
|
|
|
|
%pOFfcF /foo/bar@0:foo,device:--P- - Node full name +
|
|
|
|
major compatible string +
|
|
|
|
node flags
|
|
|
|
D - dynamic
|
|
|
|
d - detached
|
|
|
|
P - Populated
|
|
|
|
B - Populated bus
|
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
Passed by reference.
|
2017-05-16 19:27:11 -06:00
|
|
|
|
2019-10-03 06:32:18 -06:00
|
|
|
Fwnode handles
|
|
|
|
--------------
|
|
|
|
|
|
|
|
::
|
|
|
|
|
|
|
|
%pfw[fP]
|
|
|
|
|
|
|
|
For printing information on fwnode handles. The default is to print the full
|
|
|
|
node name, including the path. The modifiers are functionally equivalent to
|
|
|
|
%pOF above.
|
|
|
|
|
|
|
|
- f - full name of the node, including the path
|
|
|
|
- P - the name of the node including an address (if there is one)
|
|
|
|
|
|
|
|
Examples (ACPI)::
|
|
|
|
|
|
|
|
%pfwf \_SB.PCI0.CIO2.port@1.endpoint@0 - Full node name
|
|
|
|
%pfwP endpoint@0 - Node name
|
|
|
|
|
|
|
|
Examples (OF)::
|
|
|
|
|
|
|
|
%pfwf /ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name
|
|
|
|
%pfwP endpoint - Node name
|
|
|
|
|
2018-12-04 14:23:11 -07:00
|
|
|
Time and date (struct rtc_time)
|
|
|
|
-------------------------------
|
|
|
|
|
|
|
|
::
|
|
|
|
|
|
|
|
%ptR YYYY-mm-ddTHH:MM:SS
|
|
|
|
%ptRd YYYY-mm-dd
|
|
|
|
%ptRt HH:MM:SS
|
|
|
|
%ptR[dt][r]
|
|
|
|
|
|
|
|
For printing date and time as represented by struct rtc_time structure in
|
|
|
|
human readable format.
|
|
|
|
|
|
|
|
By default year will be incremented by 1900 and month by 1. Use %ptRr (raw)
|
|
|
|
to suppress this behaviour.
|
|
|
|
|
|
|
|
Passed by reference.
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
struct clk
|
2017-12-19 14:17:15 -07:00
|
|
|
----------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2015-04-15 17:17:20 -06:00
|
|
|
|
|
|
|
%pC pll1
|
|
|
|
%pCn pll1
|
|
|
|
|
2018-10-11 02:42:48 -06:00
|
|
|
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).
|
2015-04-15 17:17:20 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
2015-04-15 17:17:20 -06:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
bitmap and its derivatives such as cpumask and nodemask
|
2017-12-19 14:17:15 -07:00
|
|
|
-------------------------------------------------------
|
2017-05-16 19:27:11 -06:00
|
|
|
|
|
|
|
::
|
2015-02-25 20:28:25 -07:00
|
|
|
|
|
|
|
%*pb 0779
|
|
|
|
%*pbl 0,3-6,8-10
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing bitmap and its derivatives such as cpumask and nodemask,
|
2017-12-19 14:17:15 -07:00
|
|
|
%*pb outputs the bitmap with field width as the number of bits and %*pbl
|
2017-05-16 19:27:11 -06:00
|
|
|
output the bitmap as range list with field width as the number of bits.
|
2015-02-25 20:28:25 -07:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
Passed by reference.
|
|
|
|
|
|
|
|
Flags bitfields such as page flags, gfp_flags
|
2017-12-19 14:17:15 -07:00
|
|
|
---------------------------------------------
|
2008-11-12 14:26:55 -07:00
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
::
|
mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 15:55:56 -06:00
|
|
|
|
|
|
|
%pGp referenced|uptodate|lru|active|private
|
|
|
|
%pGg GFP_USER|GFP_DMA32|GFP_NOWARN
|
|
|
|
%pGv read|exec|mayread|maywrite|mayexec|denywrite
|
|
|
|
|
2017-05-16 19:27:11 -06:00
|
|
|
For printing flags bitfields as a collection of symbolic constants that
|
|
|
|
would construct the value. The type of flags is given by the third
|
|
|
|
character. Currently supported are [p]age flags, [v]ma_flags (both
|
|
|
|
expect ``unsigned long *``) and [g]fp_flags (expects ``gfp_t *``). The flag
|
|
|
|
names and print order depends on the particular type.
|
mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 15:55:56 -06:00
|
|
|
|
2017-12-19 14:17:15 -07:00
|
|
|
Note that this format should not be used directly in the
|
|
|
|
:c:func:`TP_printk()` part of a tracepoint. Instead, use the show_*_flags()
|
|
|
|
functions from <trace/events/mmflags.h>.
|
mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 15:55:56 -06:00
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2017-05-16 19:27:11 -06:00
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Passed by reference.
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Network device features
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2017-12-19 14:17:15 -07:00
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-----------------------
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mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 15:55:56 -06:00
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2017-05-16 19:27:11 -06:00
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::
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2015-11-06 17:30:17 -07:00
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%pNF 0x000000000000c000
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2017-05-16 19:27:11 -06:00
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For printing netdev_features_t.
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2015-11-06 17:30:17 -07:00
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2017-05-16 19:27:11 -06:00
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Passed by reference.
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2015-11-06 17:30:17 -07:00
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2017-12-19 14:17:15 -07:00
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Thanks
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======
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2015-11-06 17:30:17 -07:00
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2017-12-19 14:17:15 -07:00
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If you add other %p extensions, please extend <lib/test_printf.c> with
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one or more test cases, if at all feasible.
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2015-11-06 17:30:17 -07:00
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2008-11-12 14:26:55 -07:00
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Thank you for your cooperation and attention.
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