Commit Graph

173 Commits

Author SHA1 Message Date
Bjorn Helgaas 4da0b66c6e vsprintf: move %pR resource printf_specs off the stack
This adds separate I/O and memory specs, so we don't have to change the
field width in a shared spec, which then lets us make all the specs const
and static, since they never change.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 17:53:07 -08:00
Bjorn Helgaas b89dc5d6b0 vsprintf: clarify comments for printf_spec flags
Add clues about what the SMALL and SPECIAL flags do.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 17:53:07 -08:00
Joe Perches ef0658f3de vsprintf.c: Reduce sizeof struct printf_spec from 24 to 8 bytes
Reducing the size of struct printf_spec is a good thing because multiple
instances are commonly passed on stack.

It's possible for type to be u8 and field_width to be s8, but this is
likely small enough for now.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 17:47:45 -08:00
David S. Miller 51c24aaaca Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-01-23 00:31:06 -08:00
Joe Perches 0159f24ee7 lib/vsprintf.c: Add IPV4 options %pI4[hnbl] for host, network, big and little endian
This should allow the removal of the #defines and uses
of NIPQUAD and NIPQUAD_FMT

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-13 20:23:30 -08:00
Uwe Kleine-König 3f4724027b vsnprintf: fix reference for compressed ipv6 addresses
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: Josip Rodin <joy@entuzijast.net>
Cc: Joe Perches <joe@perches.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-11 09:34:06 -08:00
Joe Perches c8e000604b lib: Kill bit-reversed FDDI MAC output case, it's bogus.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-11 00:44:14 -08:00
Joe Perches bc7259a2ce lib/vsprintf.c: Add %pMF to format FDDI bit reversed MAC addresses
On Mon, 2010-01-04 at 23:43 +0000, Maciej W. Rozycki wrote:
> The example below shows an address, and the sequence of bits or symbols
> that would be transmitted when the address is used in the Source Address
> or Destination Address fields on the MAC header.  The transmission line
> shows the address bits in the order transmitted, from left to right.  For
> IEEE 802 LANs these correspond to actual bits on the medium.  The FDDI
> symbols line shows how the FDDI PHY sends the address bits as encoded
> symbols.
>
>         MSB:            35:7B:12:00:00:01
>         Canonical:      AC-DE-48-00-00-80
>         Transmission:   00110101 01111011 00010010 00000000 00000000 00000001
>         FDDI Symbols:   35 7B 12 00 00 01"
>
> Please note that this address has its group bit clear.
>
>  This notation is also defined in the "FDDI MEDIA ACCESS CONTROL-2
> (MAC-2)" (X3T9/92-120) document although that book does not have a need
> to use the MSB form and it's skipped.

Adds 6 bytes to object size for x86

New:
$ size lib/vsprintf.o
   text	   data	    bss	    dec	    hex	filename
   8664	      0	      2	   8666	   21da	lib/vsprintf.o
$ size lib/vsprintf.o
   text    data     bss     dec     hex filename
   8658       0       2    8660    21d4 lib/vsprintf.o

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-07 16:58:08 -08:00
Uwe Kleine-König 8a79503aa8 lib/vsprintf.c: document more vsnprintf extensions
These were added in

9ac6e44 (lib/vsprintf.c: add %pU to print UUID/GUIDs)
c7dabef (vsprintf: use %pR, %pr instead of %pRt, %pRf)
8a27f7c (lib/vsprintf.c: Add "%pI6c" - print pointer as compressed ipv6 address)
4aa9960 (printk: add %I4, %I6, %i4, %i6 format specifiers)
dd45c9c (printk: add %pM format specifier for MAC addresses)

but only added comments to pointer() not vsnprintf() that is refered to by
printk's comments.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joe Perches <joe@perches.com>
Cc: Jens Rosenboom <jens@mcbone.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17 15:45:31 -08:00
Joe Perches 9ac6e44ee5 lib/vsprintf.c: add %pU to print UUID/GUIDs
UUID/GUIDs are somewhat common in kernel source.

Standardize the printed style of UUID/GUIDs by using
another extension to %p.

%pUb:   01020304-0506-0708-090a-0b0c0d0e0f10
%pUB:   01020304-0506-0708-090A-0B0C0D0E0F10 (upper case)
%pUl:   04030201-0605-0807-090a-0b0c0d0e0f10
%pUL:   04030201-0605-0807-090A-0B0C0D0E0F10 (upper case)

%pU defaults to %pUb

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Jeff Garzik <jgarzik@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:33 -08:00
André Goddard Rosa e7d2860b69 tree-wide: convert open calls to remove spaces to skip_spaces() lib function
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
André Goddard Rosa 922ac25c9f vsprintf: reuse almost identical simple_strtoulX() functions
The difference between simple_strtoul() and simple_strtoull() is just
the size of the variable used to keep track of the sum of characters
converted to numbers:

unsigned long simple_strtoul() {...}
unsigned long long simple_strtoull(){...}

Both are same size on my Core 2/gcc 4.4.1.
Overflow condition is not checked on both functions, so an extremely large
string can break these functions so that they don't even notice it.

As we do not care for overflowing on these functions, always keep the sum
using the larger variable around (unsigned long long) on simple_strtoull()
and cast it to (unsigned long) on simple_strtoul(), which then becomes
just a wrapper around simple_strtoull().

Code size decreases by 304 bytes:
   text    data     bss     dec     hex filename
  15534       0       8   15542    3cb6 vsprintf.o (ex lib/lib.a-BEFORE)
  15230       0       8   15238    3b86 vsprintf.o (ex lib/lib.a-AFTER)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
André Goddard Rosa c5484d7c0a vsprintf: factor out skip_space code in a separate function
When converting more caller sites, the inline decision will be left up to gcc.

It decreases code size:
 text    data     bss     dec     hex filename
15710       0       8   15718    3d66 vsprintf.o (ex lib/lib.a-BEFORE)
15534       0       8   15542    3cb6 vsprintf.o (ex lib/lib.a-AFTER)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
André Goddard Rosa d4be151b21 vsprintf: move local vars to block local vars and remove unneeded ones
Cleanup by moving variables closer to the scope where they're used in fact.
Also, remove unneeded ones.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
André Goddard Rosa b5ff992b09 vsprintf: reduce code size by avoiding extra check
No functional change, just refactor the code so that it avoid checking
"if (hi)" two times in a sequence, taking advantage of previous check made.

It also reduces code size:
   text    data     bss     dec     hex filename
  15726       0       8   15734    3d76 vsprintf.o (ex lib/lib.a-BEFORE)
  15710       0       8   15718    3d66 vsprintf.o (ex lib/lib.a-AFTER)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
André Goddard Rosa 08562cb27d vsprintf: use TOLOWER whenever possible
It decreases code size as well:
 text    data     bss     dec     hex filename
15758       0       8   15766    3d96 vsprintf.o (ex lib/lib.a-BEFORE)
15726       0       8   15734    3d76 vsprintf.o (ex lib/lib.a-TOLOWER)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:29 -08:00
André Goddard Rosa 7b9186f5eb vsprintf: give it some care to please checkpatch.pl
Most relevant complaints were addressed.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:29 -08:00
André Goddard Rosa 6c35663411 vsprintf: pre-calculate final string length for later use
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:29 -08:00
André Goddard Rosa 0f4f81dce9 vsprintf: factorize "(null)" string
This patchset reduces lib/lib.a code size by 482 bytes on my Core 2 with
gcc 4.4.1 even considering that it exports a newly defined function
skip_spaces() to drivers:

   text    data     bss     dec     hex filename
  64867     840     592   66299   102fb (TOTALS-lib.a-BEFORE)
  64641     584     592   65817   10119 (TOTALS-lib.a-AFTER)
and implements some code tidy up.

Besides reducing lib.a size, it converts many in-tree drivers to use the
newly defined function, which makes another small reduction on kernel size
overall when those drivers are used.

This patch:

Change "<NULL>" to "(null)", unifying 3 equal strings.
glibc also uses "(null)" for the same purpose.

It decreases code size by 7 bytes:
 text    data     bss     dec     hex filename
15765       0       8   15773    3d9d vsprintf.o (ex lib/lib.a-BEFORE)
15758       0       8   15766    3d96 vsprintf.o (ex lib/lib.a-AFTER)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:29 -08:00
Bjorn Helgaas c7dabef8a2 vsprintf: use %pR, %pr instead of %pRt, %pRf
Jesse accidentally applied v1 [1] of the patchset instead of v2 [2].  This
is the diff between v1 and v2.

The changes in this patch are:
    - tidied vsprintf stack buffer to shrink and compute size more
      accurately
    - use %pR for decoding and %pr for "raw" (with type and flags) instead
      of adding %pRt and %pRf

[1] http://lkml.org/lkml/2009/10/6/491
[2] http://lkml.org/lkml/2009/10/13/441

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-04 13:06:41 -08:00
Bjorn Helgaas fd95541e23 vsprintf: add %pRt, %pRf to print struct resource details
This adds support for printing struct resource type and flag information.
For example, "%pRt" looks like "[mem 0x80080000000-0x8008001ffff 64bit pref]",
and "%pRf" looks like "[mem 0xff5e2000-0xff5e2007 pref flags 0x1]".

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-04 08:47:17 -08:00
Bjorn Helgaas c91d3376e5 vsprintf: add %pR support for IRQ and DMA resources
Print addresses (IO port numbers and memory addresses) in hex, but print
others (IRQs and DMA channels) in decimal.  Only print the end if it's
different from the start.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-04 08:47:16 -08:00
Bjorn Helgaas 2840537228 vsprintf: fix io/mem resource width
The leading "0x" consumes field width, so leave space for it in addition to
the 4 or 8 hex digits.  This means we'll print "0x0000-0x01df" rather than
"0x00-0x1df", for example.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-04 08:47:15 -08:00
Andy Spencer 8fccae2c95 sscanf(): fix %*s%n
When using %*s, sscanf should honor conversion specifiers immediately
following the %*s.  For example, the following code should find the
position of the end of the string "hello".

  int end;
  char buf[] = "hello    world";
  sscanf(buf, "%*s%n", &end);
  printf("%d\n", end);

Ideally, sscanf would advance the fmt and str pointers the same as it
would without the *, but the code for that is rather complicated and is
not included in the patch.

Signed-off-by: Andy Spencer <andy753421@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
David S. Miller 8b3f6af863 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	drivers/staging/Kconfig
	drivers/staging/Makefile
	drivers/staging/cpc-usb/TODO
	drivers/staging/cpc-usb/cpc-usb_drv.c
	drivers/staging/cpc-usb/cpc.h
	drivers/staging/cpc-usb/cpc_int.h
	drivers/staging/cpc-usb/cpcusb.h
2009-09-24 15:13:11 -07:00
Joe Perches eb78cd26b9 lib/vsprintf.c: Avoid possible unaligned accesses in %pI6c
Jens Rosenboom noticed that a possibly unaligned const char*
is cast to a const struct in6_addr *.

Avoid this at the cost of a struct in6_addr copy on the stack.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-22 14:00:05 -07:00
Marcin Slusarz 2f30b1f9e1 vsprintf: use WARN_ON_ONCE
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:47 -07:00
Steven Rostedt 0efb4d2072 vsnprintf: remove duplicate comment of vsnprintf
Remove the duplicate comment of bstr_printf that is the same as the
vsnprintf.

Add the 's' option to the comment for the pointer function. This is
more of an internal function so the little duplication of the comment
here is OK.

Reported-by: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-17 15:53:46 -04:00
Steven Rostedt 91adcd2c4b vsprintf: add %ps that is the same as %pS but is like %pf
On PowerPC64 function pointers do not point directly at the functions,
but instead point to pointers to the functions. The output of %pF expects
to point to a pointer to the function, whereas %pS will show the function
itself.

mcount returns the direct pointer to the function and not the pointer to
the pointer. Thus %pS must be used to show this. The function tracer
requires printing of the functions without offsets and uses the %pf
instead.

 %pF produces run_local_timers+0x4/0x1f
 %pf produces just run_local_timers

For PowerPC64, we need to use the direct pointer, and we only have
%pS which will produce .run_local_timers+0x4/0x1f

This patch creates a %ps that matches the %pf as %pS matches %pF.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-17 15:53:14 -04:00
Joe Perches 8a27f7c90f lib/vsprintf.c: Add "%pI6c" - print pointer as compressed ipv6 address
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Jens Rosenboom <jens@mcbone.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-29 00:19:26 -07:00
Frederic Weisbecker 0c8b946e3e vsprintf: introduce %pf format specifier
A printf format specifier which would allow us to print a pure
function name has been suggested by Andrew Morton a couple of
months ago.

The current %pF is very convenient to print a function symbol,
but often we only want to print the name of the function, without
its asm offset.

That's what  %pf does in this patch.  The lowecase f has been chosen
for its intuitive meaning of a 'weak kind of %pF'.

The support for this new format would be welcome by the tracing code
where the need to print pure function names is often needed. This is
also true for other parts of the kernel:

$ git-grep -E "kallsyms_lookup\(.+?\)"
arch/blackfin/kernel/traps.c:   symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
arch/powerpc/xmon/xmon.c:               name = kallsyms_lookup(pc, &size, &offset, NULL, tmpstr);
arch/sh/kernel/cpu/sh5/unwind.c:        sym = kallsyms_lookup(pc, NULL, &offset, NULL, namebuf);
arch/x86/kernel/ftrace.c:       kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str);
kernel/kprobes.c:               sym = kallsyms_lookup((unsigned long)p->addr, NULL,
kernel/lockdep.c:       return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
kernel/trace/ftrace.c:  kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
kernel/trace/ftrace.c:  kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
kernel/trace/ftrace.c:  kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
kernel/trace/ftrace.c:  kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
kernel/trace/ftrace.c:  kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
kernel/trace/ftrace.c:  kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
kernel/trace/ftrace.c:  kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
kernel/trace/trace_functions.c: kallsyms_lookup(ip, NULL, NULL, NULL, str);
kernel/trace/trace_output.c:    kallsyms_lookup(address, NULL, NULL, NULL, str);

Changes in v2:

- Add the explanation of the %pf role for vsnprintf() and bstr_printf()

- Change the comments by dropping the "asm offset" notion and only
  define the %pf against the actual function offset notion.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090415154817.GC5989@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 20:55:55 +02:00
Zhaolei a4e94ef0dd printk: add support of hh length modifier for printk
Impact: new feature, extend vsprintf format strings

hh is used as length modifier for signed char or unsigned char.
It is supported by glibc, we add kernel support now.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: torvalds@linux-foundation.org
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49CC9739.30107@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-08 17:04:30 +02:00
Zhaolei 022624a758 printk: fix wrong format string iter for printk
printk("%Q");

 Output before patch:  %QQ
 Output  after patch:  %Q

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: torvalds@linux-foundation.org
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49CC97B6.7040809@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-08 17:03:44 +02:00
Vegard Nossum ed681a91ab vsprintf: unify the format decoding layer for its 3 users, cleanup
Impact: cleanup

Rename FORMAT_TYPE_WITDH
 to => FORMAT_TYPE_WIDTH

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-14 12:37:09 +01:00
Vegard Nossum adf26f84a6 fix regression from "vsprintf: unify the format decoding layer for its 3 users"
Jeremy Fitzhardinge reported:

> Change fef20d9c13, "vsprintf:
> unify the format decoding layer for its 3 users", causes a
> regression in xenbus which results in no devices getting
> attached to a new domain.

%.*s is broken - fix it.

Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-14 12:37:08 +01:00
Frederic Weisbecker 39e874f8af vsprintf: fix bug in negative value printing
Sitsofe Wheeler found and bisected that while unifying the
vsprintf format decoding in:

  fef20d9: vsprintf: unify the format decoding layer for its 3 users

The sign flag has been dropped out in favour of
precise types (ie: LONG/ULONG).

But the format helper number() still needs this flag to keep track of
the signedness unless it will consider all numbers as unsigned.

Also add an explicit cast to int (for %d) while parsing with va_arg()
to ensure the highest bit is well extended on the 64 bits number that
hosts the value in case of negative values.

Reported-Bisected-Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20090309201503.GA5010@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 13:15:06 +01:00
Frederic Weisbecker fef20d9c13 vsprintf: unify the format decoding layer for its 3 users
An new optimization is making its way to ftrace. Its purpose is to
make trace_printk() consuming less memory and be faster.

Written by Lai Jiangshan, the approach is to delay the formatting
job from tracing time to output time.

Currently, a call to trace_printk() will format the whole string and
insert it into the ring buffer. Then you can read it on /debug/tracing/trace
file.

The new implementation stores the address of the format string and
the binary parameters into the ring buffer, making the packet more compact
and faster to insert.
Later, when the user exports the traces, the format string is retrieved
with the binary parameters and the formatting job is eventually done.

The new implementation rewrites a lot of format decoding bits from
vsnprintf() function, making now 3 differents functions to maintain
in their duplicated parts of printf format decoding bits.

Suggested by Ingo Molnar, this patch tries to factorize the most
possible common bits from these functions.
The real common part between them is the format decoding. Although
they do somewhat similar jobs, their way to export or import the parameters
is very different. Thus, only the decoding layer is extracted, unless you see
other parts that could be worth factorized.

Changes in V2:

- Address a suggestion from Linus to group the format_decode() parameters inside
  a structure.

Changes in v3:

- Address other cleanups suggested by Ingo and Linus such as passing the
  printf_spec struct to the format helpers: pointer()/number()/string()
  Note that this struct is passed by copy and not by address. This is to
  avoid side effects because these functions often change these values and the
  changes shoudn't be persistant when a callee helper returns.
  It would be too risky.

- Various cleanups (code alignement, switch/case instead of if/else fountains).

- Fix a bug that printed the first format specifier following a %p

Changes in v4:

- drop unapropriate const qualifier loss while casting fmt to a char *
  (thanks to Vegard Nossum for having pointed this out).

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-6-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 17:44:27 +01:00
Lai Jiangshan 4370aa4aa7 vsprintf: add binary printf
Impact: add new APIs for binary trace printk infrastructure

vbin_printf(): write args to binary buffer, string is copied
when "%s" is occurred.

bstr_printf(): read from binary buffer for args and format a string

[fweisbec@gmail.com: rebase]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1236356510-8381-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 17:39:04 +01:00
Pavel Machek e899aa823a strict_strto* is not strict enough
It decodes "\n" as 0, which is bad, because stray echo into backlight
will turn your backlight off, etc...

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: Yi Yang <yi.y.yang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:12 -08:00
Linus Torvalds d97106ab53 Make %p print '(null)' for NULL pointers
Before, when we only ever printed out the pointer value itself, a NULL
pointer would never cause issues and might as well be printed out as
just its numeric value.

However, with the extended %p formats, especially %pR, we might validly
want to print out resources for debugging.  And sometimes they don't
even exist, and the resource pointer is just NULL.  Print it out as
such, rather than oopsing.

This is a more generic version of a patch done by Trent Piepho (catching
all %p cases rather than just %pR, and using "(null)" instead of
"[NULL]" to match glibc).

Requested-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-03 11:46:17 -08:00
Harvey Harrison 411c41eea5 aoe: remove private mac address format function
Add %pm to omit the colons when printing a mac address.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 00:40:37 -08:00
Harvey Harrison b9ac99855d printk: ipv4 address digits printed in reverse order
put_dec_trunc prints the digits in reverse order and is reversed
inside number(). Continue using put_dec_trunc, but reverse each quad
in ip4_addr_string.

[Noticed by Julius Volz]

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03 17:09:55 -08:00
Harvey Harrison 6b9a1066f8 printk: remove %p6 format specifier, fix up comments
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 12:53:10 -07:00
Harvey Harrison 4aa996066f printk: add %I4, %I6, %i4, %i6 format specifiers
For use in printing IPv4, or IPv6 addresses in the usual way:

%i4 and %I4 are currently equivalent and print the address in
dot-separated decimal x.x.x.x

%I6 prints 16-bit network order hex with colon separators:
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx

%i6 omits the colons.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29 12:49:58 -07:00
Harvey Harrison 689afa7da1 printk: add %p6 format specifier for IPv6 addresses
Takes a pointer to a IPv6 address and formats it in the usual
colon-separated hex format:
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx

Each 16 bit word is printed in network-endian byteorder.

%#p6 is also supported and will omit the colons.

%p6 is a replacement for NIP6_FMT and NIP6()
%#p6 is a replacement for NIP6_SEQFMT and NIP6()

Note that NIP6() took a struct in6_addr whereas this takes a pointer
to a struct in6_addr.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28 16:04:44 -07:00
Harvey Harrison dd45c9cf68 printk: add %pM format specifier for MAC addresses
Add format specifiers for printing out six colon-separated bytes:

MAC addresses (%pM):
xx:xx:xx:xx:xx:xx

%#pM is also supported and omits the colon separators.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-27 17:06:15 -07:00
Linus Torvalds 332d2e7834 Implement %pR to print struct resource content
Add a %pR option to the kernel vsnprintf that prints the range of
addresses inside a struct resource passed by pointer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 09:12:32 -07:00
Harvey Harrison 9d85db2244 lib: remove defining macros for strict_strto??
Open-code them rather than using defining macros.  The function bodies are now
next to their kerneldoc comments as a bonus.

Add casts to the signed cases as they call into the unsigned versions.

Avoids the sparse warnings:
lib/vsprintf.c:249:1: warning: incorrect type in argument 3 (different signedness)
lib/vsprintf.c:249:1:    expected unsigned long *res
lib/vsprintf.c:249:1:    got long *res
lib/vsprintf.c:249:1: warning: incorrect type in argument 3 (different signedness)
lib/vsprintf.c:249:1:    expected unsigned long *res
lib/vsprintf.c:249:1:    got long *res
lib/vsprintf.c:251:1: warning: incorrect type in argument 3 (different signedness)
lib/vsprintf.c:251:1:    expected unsigned long long *res
lib/vsprintf.c:251:1:    got long long *res
lib/vsprintf.c:251:1: warning: incorrect type in argument 3 (different signedness)
lib/vsprintf.c:251:1:    expected unsigned long long *res
lib/vsprintf.c:251:1:    got long long *res

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 14:58:08 -07:00
Harvey Harrison 22d27051b4 lib: trivial whitespace tidy
Remove extra lines before the EXPORT_SYMBOL()s

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 14:58:07 -07:00
Harvey Harrison aa46a63efc lib: pull base-guessing logic to helper function
The default base is 10 unless there is a leading zero, in which
case the base will be guessed as 8.

The base will only be guesed as 16 when the string starts with '0x'
the third character is a valid hex digit.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 14:58:07 -07:00
Andi Kleen 20036fdcaf Add kerneldoc documentation for new printk format extensions
Add documentation in kerneldoc for new printk format extensions

This patch documents the new %pS/%pF options in printk in kernel doc.

Hope I didn't miss any other extension.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:32 -07:00
James Bottomley deac93df26 lib: Correct printk %pF to work on all architectures
It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef24f7.  However,
the current way its coded doesn't work on parisc64.  For two reasons: 1)
parisc isn't in the #ifdef and 2) parisc has a different format for
function descriptors

Make dereference_function_descriptor() more accommodating by allowing
architecture overrides.  I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-09 11:51:15 -07:00
Yi Yang 29a6d39bf3 lib/vsprintf.c: wrong conversion function used
Fix wrong conversion function used by strict_strtou*

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Reported-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12 16:07:29 -07:00
Linus Torvalds 0fe1ef24f7 vsprintf: add support for '%pS' and '%pF' pointer formats
They print out a pointer in symbolic format, if possible (ie using
symbolic KALLSYMS information).  The '%pS' format is for regular direct
pointers (which can point to data or code and that you find on the stack
during backtraces etc), while '%pF' is for C function pointer types.

On most architectures, the two mean exactly the same thing, but some
architectures use an indirect pointer for C function pointers, where the
function pointer points to a function descriptor (which in turn contains
the actual pointer to the code).  The '%pF' code automatically does the
appropriate function descriptor dereference on such architectures.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-06 16:55:51 -07:00
Linus Torvalds 4d8a743cdd vsprintf: add infrastructure support for extended '%p' specifiers
This expands the kernel '%p' handling with an arbitrary alphanumberic
specifier extension string immediately following the '%p'.  Right now
it's just being ignored, but the next commit will start adding some
specific pointer type extensions.

NOTE! The reason the extension is appended to the '%p' is to allow
minimal gcc type checking: gcc will still see the '%p' and will check
that the argument passed in is indeed a pointer, and yet will not
complain about the extended information that gcc doesn't understand
about (on the other hand, it also won't actually check that the pointer
type and the extension are compatible).

Alphanumeric characters were chosen because there is no sane existing
use for a string format with a hex pointer representation immediately
followed by alphanumerics (which is what such a format string would have
traditionally resulted in).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-06 16:24:57 -07:00
Linus Torvalds 78a8bf69b3 vsprintf: split out '%p' handling logic
The actual code is the same, just split out into a helper function.
This makes it easier to read, and allows for simple future extension
of %p handling.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-06 16:16:15 -07:00
Linus Torvalds 0f9bfa569d vsprintf: split out '%s' handling logic
The actual code is the same, just split out into a helper function.
This makes it easier to read, and allows for future sharing of the
string code.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-06 16:06:25 -07:00
Hoang-Nam Nguyen 4f9d5f4a35 lib/vsprintf.c: fix bug omitting minus sign of numbers (module_param)
lib/vsprintf.c: Fix bug omitting minus sign of numbers (module_param)

Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Cc: Yi Yang <yi.y.yang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 17:12:14 -08:00
Denys Vlasenko 9b706aee7d x86: trivial printk optimizations
In arch/x86/boot/printf.c gets rid of unused tail of digits: const char
*digits = "0123456789abcdefghijklmnopqrstuvwxyz"; (we are using 0-9a-f
only)

Uses smaller/faster lowercasing (by ORing with 0x20)
if we know that we work on numbers/digits. Makes
strtoul smaller, and also we are getting rid of

  static const char small_digits[] = "0123456789abcdefx";
  static const char large_digits[] = "0123456789ABCDEFX";

since this works equally well:

  static const char digits[16] = "0123456789ABCDEF";

Size savings:

$ size vmlinux.org vmlinux
   text    data     bss     dec     hex filename
 877320  112252   90112 1079684  107984 vmlinux.org
 877048  112252   90112 1079412  107874 vmlinux

It may be also a tiny bit faster because code has less
branches now, but I doubt it is measurable.

[ hugh@veritas.com: uppercase pointers fix ]

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-09 23:24:09 +01:00
Yi Yang 06b2a76d25 Add new string functions strict_strto* and convert kernel params to use them
Currently, for every sysfs node, the callers will be responsible for
implementing store operation, so many many callers are doing duplicate
things to validate input, they have the same mistakes because they are
calling simple_strtol/ul/ll/uul, especially for module params, they are
just numeric, but you can echo such values as 0x1234xxx, 07777888 and
1234aaa, for these cases, module params store operation just ignores
succesive invalid char and converts prefix part to a numeric although input
is acctually invalid.

This patch tries to fix the aforementioned issues and implements
strict_strtox serial functions, kernel/params.c uses them to strictly
validate input, so module params will reject such values as 0x1234xxxx and
returns an error:

write error: Invalid argument

Any modules which export numeric sysfs node can use strict_strtox instead of
simple_strtox to reject any invalid input.

Here are some test results:

Before applying this patch:

[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0x1000 > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0x1000g > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0x1000gggggggg > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 010000 > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0100008 > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 010000aaaaa > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]#

After applying this patch:

[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0x1000 > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0x1000g > /sys/module/e1000/parameters/copybreak
-bash: echo: write error: Invalid argument
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo 0x1000gggggggg > /sys/module/e1000/parameters/copybreak
-bash: echo: write error: Invalid argument
[root@yangyi-dev /]# echo 010000 > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# echo 0100008 > /sys/module/e1000/parameters/copybreak
-bash: echo: write error: Invalid argument
[root@yangyi-dev /]# echo 010000aaaaa > /sys/module/e1000/parameters/copybreak
-bash: echo: write error: Invalid argument
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]# echo -n 4096 > /sys/module/e1000/parameters/copybreak
[root@yangyi-dev /]# cat /sys/module/e1000/parameters/copybreak
4096
[root@yangyi-dev /]#

[akpm@linux-foundation.org: fix compiler warnings]
[akpm@linux-foundation.org: fix off-by-one found by tiwai@suse.de]
Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:41 -08:00
Sam Ravnborg 96e3e18eed lib: move kasprintf to a separate file
kasprintf pulls in kmalloc which proved to be fatal for at least
bootimage target on alpha.
Move it to a separate file so only users of kasprintf are exposed
to the dependency on kmalloc.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jay Estabrook <jay.estabrook@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:39 -07:00
Denis Vlasenko 4277eedd79 vsprintf.c: optimizing, part 2: base 10 conversion speedup, v2
Optimize integer-to-string conversion in vsprintf.c for base 10.  This is
by far the most used conversion, and in some use cases it impacts
performance.  For example, top reads /proc/$PID/stat for every process, and
with 4000 processes decimal conversion alone takes noticeable time.

Using code from

http://www.cs.uiowa.edu/~jones/bcd/decimal.html
(with permission from the author, Douglas W. Jones)

binary-to-decimal-string conversion is done in groups of five digits at
once, using only additions/subtractions/shifts (with -O2; -Os throws in
some multiply instructions).

On i386 arch gcc 4.1.2 -O2 generates ~500 bytes of code.

This patch is run tested. Userspace benchmark/test is also attached.
I tested it on PIII and AMD64 and new code is generally ~2.5 times
faster. On AMD64:

# ./vsprintf_verify-O2
Original decimal conv: .......... 151 ns per iteration
Patched decimal conv:  .......... 62 ns per iteration
Testing correctness
12895992590592 ok...        [Ctrl-C]
# ./vsprintf_verify-O2
Original decimal conv: .......... 151 ns per iteration
Patched decimal conv:  .......... 62 ns per iteration
Testing correctness
26025406464 ok...        [Ctrl-C]

More realistic test: top from busybox project was modified to
report how many us it took to scan /proc (this does not account
any processing done after that, like sorting process list),
and then I test it with 4000 processes:

#!/bin/sh
i=4000
while test $i != 0; do
    sleep 30 &
    let i--
done
busybox top -b -n3 >/dev/null

on unpatched kernel:

top: 4120 processes took 102864 microseconds to scan
top: 4120 processes took 91757 microseconds to scan
top: 4120 processes took 92517 microseconds to scan
top: 4120 processes took 92581 microseconds to scan

on patched kernel:

top: 4120 processes took 75460 microseconds to scan
top: 4120 processes took 66451 microseconds to scan
top: 4120 processes took 67267 microseconds to scan
top: 4120 processes took 67618 microseconds to scan

The speedup comes from much faster generation of /proc/PID/stat
by sprintf() calls inside the kernel.

Signed-off-by: Douglas W Jones <jones@cs.uiowa.edu>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:52 -07:00
Denis Vlasenko b39a734097 vsprintf.c: optimizing, part 1 (easy and obvious stuff)
* There is no point in having full "0...9a...z" constant vector,
  if we use only "0...9a...f" (and "x" for "0x").

* Post-decrement usually needs a few more instructions, so use
  pre decrement instead where makes sense:
-       while (i < precision--) {
+       while (i <= --precision) {

* if base != 10 (=> base 8 or 16), we can avoid using division
  in a loop and use mask/shift, obtaining much faster conversion.
  (More complex optimization for base 10 case is in the second patch).

Overall, size vsprintf.o shows ~80 bytes smaller text section
with this patch applied.

Signed-off-by: Douglas W Jones <jones@cs.uiowa.edu>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:52 -07:00
Johannes Berg c6b40d16d1 fix sscanf %n match at end of input string
I was playing with some code that sometimes got a string where a %n
match should have been done where the input string ended, for example
like this:

  sscanf("abc123", "abc%d%n", &a, &n);  /* doesn't work */
  sscanf("abc123a", "abc%d%n", &a, &n); /* works */

However, the scanf function in the kernel doesn't convert the %n in that
case because it has already matched the complete input after %d and just
completely stops matching then. This patch fixes that.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:05 -07:00
Jeremy Fitzhardinge 11443ec7d9 Add kvasprintf()
Add a kvasprintf() function to complement kasprintf().

No in-tree users yet, but I have some coming up.

[akpm@linux-foundation.org: EXPORT it]
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Keir Fraser <keir@xensource.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30 16:40:40 -07:00
Martin Peschke ea6f3281a1 [PATCH] scnprintf(): fix a comment
The return value of scnprintf() never exceeds @size.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:28 -08:00
Robert P. J. Day 72fd4a35a8 [PATCH] Numerous fixes to kernel-doc info in source files.
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in
source files, including:

  * make multi-line initial descriptions single line
  * denote some function names, constants and structs as such
  * change erroneous opening '/*' to '/**' in a few places
  * reword some text for clarity

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:32 -08:00
Linus Torvalds 0a6047eef1 Fix vsnprintf off-by-one bug
The recent vsnprintf() fix introduced an off-by-one, and it's now
possible to overrun the target buffer by one byte.

The "end" pointer points to past the end of the buffer, so if we
have to truncate the result, it needs to be done though "end[-1]".

[ This is just an alternate and simpler patch to one proposed by Andrew
  and Jeremy, who actually noticed the problem ]

Acked-by: Andrew Morton <akpm@osdl.org>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28 17:09:34 -07:00
Jeremy Fitzhardinge e905914f96 [PATCH] Implement kasprintf
Implement kasprintf, a kernel version of asprintf.  This allocates the
memory required for the formatted string, including the trailing '\0'.
Returns NULL on allocation failure.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:23 -07:00
Jeremy Fitzhardinge f796937a06 [PATCH] Fix bounds check in vsnprintf, to allow for a 0 size and NULL buffer
This change allows callers to use a 0-byte buffer and a NULL buffer pointer
with vsnprintf, so it can be used to determine how large the resulting
formatted string will be.

Previously the code effectively treated a size of 0 as a size of 4G (on
32-bit systems), with other checks preventing it from actually trying to
emit the string - but the terminal \0 would still be written, which would
crash if the buffer is NULL.

This change changes the boundary check so that 'end' points to the putative
location of the terminal '\0', which is only written if size > 0.

vsnprintf still allows the buffer size to be set very large, to allow
unbounded buffer sizes (to implement sprintf, etc).

[akpm@osdl.org: fix long-vs-longlong confusion]
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:23 -07:00
Tim Schmielau 4e57b68178 [PATCH] fix missing includes
I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.

In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch.  This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other.  So if any
hunk rejects or gets in the way of other patches, just drop it.  My scripts
will pick it up again in the next round.

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:32 -08:00
Al Viro 8032230694 [PATCH] %t... in vsnprintf
handling of %t... (ptrdiff_t) in vsnprintf

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-23 18:43:46 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00