Граф коммитов

20 Коммитов

Автор SHA1 Сообщение Дата
Joe Perches 61e99ab8e3 printk: remove the now unnecessary "C" annotation for KERN_CONT
Now that all KERN_<LEVEL> uses are prefixed with ASCII SOH, there is no
need for a KERN_CONT.  Keep it backward compatible by adding #define
KERN_CONT ""

Reduces kernel image size a thousand bytes.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:14 -07:00
Joe Perches 04d2c8c83d printk: convert the format for KERN_<LEVEL> to a 2 byte pattern
Instead of "<.>", use an ASCII SOH for the KERN_<LEVEL> prefix initiator.

This saves 1 byte per printk, thousands of bytes in a normal kernel.

No output changes are produced as vprintk_emit converts these uses to
"<.>".

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:14 -07:00
Joe Perches 314ba3520e printk: add kern_levels.h to make KERN_<LEVEL> available for asm use
Separate the printk.h file into 2 pieces so the definitions can be used in
asm files.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:13 -07:00
Joe Perches acc8fa41ad printk: add generic functions to find KERN_<LEVEL> headers
The current form of a KERN_<LEVEL> is "<.>".

Add printk_get_level and printk_skip_level functions to handle these
formats.

These functions centralize tests of KERN_<LEVEL> so a future modification
can change the KERN_<LEVEL> style and shorten the number of bytes consumed
by these headers.

[akpm@linux-foundation.org: fix build error and warning]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:13 -07:00
Kay Sievers e11fea92e1 kmsg: export printk records to the /dev/kmsg interface
Support for multiple concurrent readers of /dev/kmsg, with read(),
seek(), poll() support. Output of message sequence numbers, to allow
userspace log consumers to reliably reconnect and reconstruct their
state at any given time. After open("/dev/kmsg"), read() always
returns *all* buffered records. If only future messages should be
read, SEEK_END can be used. In case records get overwritten while
/dev/kmsg is held open, or records get faster overwritten than they
are read, the next read() will return -EPIPE and the current reading
position gets updated to the next available record. The passed
sequence numbers allow the log consumer to calculate the amount of
lost messages.

  [root@mop ~]# cat /dev/kmsg
  5,0,0;Linux version 3.4.0-rc1+ (kay@mop) (gcc version 4.7.0 20120315 ...
  6,159,423091;ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
  7,160,424069;pci_root PNP0A03:00: host bridge window [io  0x0000-0x0cf7] (ignored)
   SUBSYSTEM=acpi
   DEVICE=+acpi:PNP0A03:00
  6,339,5140900;NET: Registered protocol family 10
  30,340,5690716;udevd[80]: starting version 181
  6,341,6081421;FDC 0 is a S82078B
  6,345,6154686;microcode: CPU0 sig=0x623, pf=0x0, revision=0x0
  7,346,6156968;sr 1:0:0:0: Attached scsi CD-ROM sr0
   SUBSYSTEM=scsi
   DEVICE=+scsi:1:0:0:0
  6,347,6289375;microcode: CPU1 sig=0x623, pf=0x0, revision=0x0

Cc: Karel Zak <kzak@redhat.com>
Tested-by: William Douglas <william.douglas@intel.com>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07 17:03:27 -07:00
Kay Sievers 7ff9554bb5 printk: convert byte-buffer to variable-length record buffer
- Record-based stream instead of the traditional byte stream
  buffer. All records carry a 64 bit timestamp, the syslog facility
  and priority in the record header.

- Records consume almost the same amount, sometimes less memory than
  the traditional byte stream buffer (if printk_time is enabled). The record
  header is 16 bytes long, plus some padding bytes at the end if needed.
  The byte-stream buffer needed 3 chars for the syslog prefix, 15 char for
  the timestamp and a newline.

- Buffer management is based on message sequence numbers. When records
  need to be discarded, the reading heads move on to the next full
  record. Unlike the byte-stream buffer, no old logged lines get
  truncated or partly overwritten by new ones. Sequence numbers also
  allow consumers of the log stream to get notified if any message in
  the stream they are about to read gets discarded during the time
  of reading.

- Better buffered IO support for KERN_CONT continuation lines, when printk()
  is called multiple times for a single line. The use of KERN_CONT is now
  mandatory to use continuation; a few places in the kernel need trivial fixes
  here. The buffering could possibly be extended to per-cpu variables to allow
  better thread-safety for multiple printk() invocations for a single line.

- Full-featured syslog facility value support. Different facilities
  can tag their messages. All userspace-injected messages enforce a
  facility value > 0 now, to be able to reliably distinguish them from
  the kernel-generated messages. Independent subsystems like a
  baseband processor running its own firmware, or a kernel-related
  userspace process can use their own unique facility values. Multiple
  independent log streams can co-exist that way in the same
  buffer. All share the same global sequence number counter to ensure
  proper ordering (and interleaving) and to allow the consumers of the
  log to reliably correlate the events from different facilities.

Tested-by: William Douglas <william.douglas@intel.com>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07 16:53:02 -07:00
Linus Torvalds 4a52246302 driver core merge for 3.4-rc1
Here's the big driver core merge for 3.4-rc1.
 
 Lots of various things here, sysfs fixes/tweaks (with the nlink breakage
 reverted), dynamic debugging updates, w1 drivers, hyperv driver updates,
 and a variety of other bits and pieces, full information in the
 shortlog.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core patches for 3.4-rc1 from Greg KH:
 "Here's the big driver core merge for 3.4-rc1.

  Lots of various things here, sysfs fixes/tweaks (with the nlink
  breakage reverted), dynamic debugging updates, w1 drivers, hyperv
  driver updates, and a variety of other bits and pieces, full
  information in the shortlog."

* tag 'driver-core-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (78 commits)
  Tools: hv: Support enumeration from all the pools
  Tools: hv: Fully support the new KVP verbs in the user level daemon
  Drivers: hv: Support the newly introduced KVP messages in the driver
  Drivers: hv: Add new message types to enhance KVP
  regulator: Support driver probe deferral
  Revert "sysfs: Kill nlink counting."
  uevent: send events in correct order according to seqnum (v3)
  driver core: minor comment formatting cleanups
  driver core: move the deferred probe pointer into the private area
  drivercore: Add driver probe deferral mechanism
  DS2781 Maxim Stand-Alone Fuel Gauge battery and w1 slave drivers
  w1_bq27000: Only one thread can access the bq27000 at a time.
  w1_bq27000 - remove w1_bq27000_write
  w1_bq27000: remove unnecessary NULL test.
  sysfs: Fix memory leak in sysfs_sd_setsecdata().
  intel_idle: Revert change of auto_demotion_disable_flags for Nehalem
  w1: Fix w1_bq27000
  driver-core: documentation: fix up Greg's email address
  powernow-k6: Really enable auto-loading
  powernow-k7: Fix CPU family number
  ...
2012-03-20 11:16:20 -07:00
Peter Zijlstra 3ccf3e8306 printk/sched: Introduce special printk_sched() for those awkward moments
There's a few awkward printk()s inside of scheduler guts that people
prefer to keep but really are rather deadlock prone. Fudge around it
by storing the text in a per-cpu buffer and poll it using the existing
printk_tick() handler.

This will drop output when its more frequent than once a tick, however
only the affinity thing could possible go that fast and for that just
one should suffice to notify the admin he's done something silly..

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-wua3lmkt3dg8nfts66o6brne@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-12 20:43:16 +01:00
Jim Cromie b558c96ffa dynamic_debug: make dynamic-debug supersede DEBUG ccflag
If CONFIG_DYNAMIC_DEBUG is defined, honor it over DEBUG, so that
pr_debug()s are controllable, instead of always-on.  When DEBUG is
also defined, change _DPRINTK_FLAGS_DEFAULT to enable printing by
default.

Also adding _DPRINTK_FLAGS_INCL_MODNAME would be nice, but there are
numerous cases of pr_debug(NAME ": ...), which would result in double
printing of module-name.  So defer this until things settle.

Cc: David Miller <davem@davemloft.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-24 12:46:44 -08:00
Joe Perches b9075fa968 treewide: use __printf not __attribute__((format(printf,...)))
Standardize the style for compiler based printf format verification.
Standardized the location of __printf too.

Done via script and a little typing.

$ grep -rPl --include=*.[ch] -w "__attribute__" * | \
  grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \
  xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*\)\s*\)\s*\)/__printf($1, $2)/g ; print; }'

[akpm@linux-foundation.org: revert arch bits]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:54 -07:00
Mike Travis 162a7e7500 printk: allocate kernel log buffer earlier
On larger systems, because of the numerous ACPI, Bootmem and EFI messages,
the static log buffer overflows before the larger one specified by the
log_buf_len param is allocated.  Minimize the overflow by allocating the
new log buffer as soon as possible.

On kernels without memblock, a later call to setup_log_buf from
kernel/init.c is the fallback.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix CONFIG_PRINTK=n build]
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:48 -07:00
Joe Perches a3f938bf6f include/linux/printk.h: use tab not spaces for indent
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:10 -08:00
Joe Perches 6ec42a56e2 include/linux/printk.h: organize printk_ratelimited macros
- Use no_printk for !CONFIG_PRINTK printk_ratelimited.

- Whitespace cleanup.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:10 -08:00
Joe Perches ac83ed6878 include/linux/printk.h lib/hexdump.c: neatening and add CONFIG_PRINTK guard
- Move prototypes and align arguments.

- Add CONFIG_PRINTK guard for print_hex functions

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:10 -08:00
Joe Perches 16cb839f13 include/linux/printk.h: add pr_<level>_once macros
- Move printk_once definitions and add an #ifdef CONFIG_PRINTK

- Add pr_<level>_once so printks can use pr_fmt

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:09 -08:00
Joe Perches 5264f2f75d include/linux/printk.h: use and neaten no_printk
- Move no_printk above first CONFIG_PRINTK block so it can be used by
  printk_once.

- Convert statement expression if (0) printk macros to no_printk.

- Convert printk_once(x...) to more normally used (fmt, ...) fmt,
  ##__VA_ARGS__.

- Standardize __attribute__ use.

- Expand single line inline functions.

- Remove space before pointer.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:09 -08:00
Joe Perches 7d1e91aeb3 include/linux/printk.h: use space after #define
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:09 -08:00
Joe Perches a9747cc3ad include/linux/printk.h: move console functions and variables together
There are many uses of printk_once(KERN_<level>, so add pr_<level>_once
macros to avoid printk_once(KERN_<level> pr_fmt(fmt).

Add an #ifdef CONFIG_PRINTK for print_hex_dump and static inline void
functions for the #else cases to reduce embedded code size.  Neaten and
organize the rest of the code.

This patch:

Move console functions and variables together.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:09 -08:00
Dan Rosenberg 455cd5ab30 kptr_restrict for hiding kernel pointers from unprivileged users
Add the %pK printk format specifier and the /proc/sys/kernel/kptr_restrict
sysctl.

The %pK format specifier is designed to hide exposed kernel pointers,
specifically via /proc interfaces.  Exposing these pointers provides an
easy target for kernel write vulnerabilities, since they reveal the
locations of writable structures containing easily triggerable function
pointers.  The behavior of %pK depends on the kptr_restrict sysctl.

If kptr_restrict is set to 0, no deviation from the standard %p behavior
occurs.  If kptr_restrict is set to 1, the default, if the current user
(intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
(currently in the LSM tree), kernel pointers using %pK are printed as 0's.
 If kptr_restrict is set to 2, kernel pointers using %pK are printed as
0's regardless of privileges.  Replacing with 0's was chosen over the
default "(null)", which cannot be parsed by userland %p, which expects
"(nil)".

[akpm@linux-foundation.org: check for IRQ context when !kptr_restrict, save an indent level, s/WARN/WARN_ONCE/]
[akpm@linux-foundation.org: coding-style fixup]
[randy.dunlap@oracle.com: fix kernel/sysctl.c warning]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Graf <tgraf@infradead.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Paris <eparis@parisplace.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:08 -08:00
Linus Torvalds 968ab1838a include/linux/kernel.h: Move logging bits to include/linux/printk.h
Move the logging bits from kernel.h into printk.h so that
there is a bit more logical separation of the generic from
the printk logging specific parts.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-15 13:37:37 -08:00