kptr_restrict has been triggering bugs in apps such as perf, and it also makes
the system less useful by default, so turn it off by default.
This is how we generally handle security features that remove functionality,
such as firewall code or SELinux - they have to be configured and activated
from user-space.
Distributions can turn kptr_restrict on again via this line in
/etc/sysctrl.conf:
kernel.kptr_restrict = 1
( Also mark the variable __read_mostly while at it, as it's typically modified
only once per bootup, or not at all. )
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Fix WARN_ON() test for UP
WARN_ON_SMP(): Allow use in if() statements on UP
x86, dumpstack: Use %pB format specifier for stack trace
vsprintf: Introduce %pB format specifier
lockdep: Remove unused 'factor' variable from lockdep_stats_show()
The %pB format specifier is for stack backtrace. Its handler
sprint_backtrace() does symbol lookup using (address-1) to
ensure the address will not point outside of the function.
If there is a tail-call to the function marked "noreturn",
gcc optimized out the code after the call then causes saved
return address points outside of the function (i.e. the start
of the next function), so pollutes call trace somewhat.
This patch adds the %pB printk mechanism that allows architecture
call-trace printout functions to improve backtrace printouts.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
LKML-Reference: <1300934550-21394-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1. simple_strto*() do not contain overflow checks and crufty,
libc way to indicate failure.
2. strict_strto*() also do not have overflow checks but the name and
comments pretend they do.
3. Both families have only "long long" and "long" variants,
but users want strtou8()
4. Both "simple" and "strict" prefixes are wrong:
Simple doesn't exactly say what's so simple, strict should not exist
because conversion should be strict by default.
The solution is to use "k" prefix and add convertors for more types.
Enter
kstrtoull()
kstrtoll()
kstrtoul()
kstrtol()
kstrtouint()
kstrtoint()
kstrtou64()
kstrtos64()
kstrtou32()
kstrtos32()
kstrtou16()
kstrtos16()
kstrtou8()
kstrtos8()
Include runtime testsuite (somewhat incomplete) as well.
strict_strto*() become deprecated, stubbed to kstrto*() and
eventually will be removed altogether.
Use kstrto*() in code today!
Note: on some archs _kstrtoul() and _kstrtol() are left in tree, even if
they'll be unused at runtime. This is temporarily solution,
because I don't want to hardcode list of archs where these
functions aren't needed. Current solution with sizeof() and
__alignof__ at least always works.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In an effort to reduce kernel address leaks that might be used to help
target kernel privilege escalation exploits, this patch uses %pK when
displaying addresses in /proc/kallsyms, /proc/modules, and
/sys/module/*/sections/*.
Note that this changes %x to %p, so some legitimately 0 values in
/proc/kallsyms would have changed from 00000000 to "(null)". To avoid
this, "(null)" is not used when using the "K" format. Anything that was
already successfully parsing "(null)" in addition to full hex digits
should have no problem with this change. (Thanks to Joe Perches for the
suggestion.) Due to the %x to %p, "void *" casts are needed since these
addresses are already "unsigned long" everywhere internally, due to their
starting life as ELF section offsets.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Cc: Eugene Teo <eugene@redhat.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If kptr restrictions are on, just set the passed pointer to NULL.
$ size lib/vsprintf.o.*
text data bss dec hex filename
8247 4 2 8253 203d lib/vsprintf.o.new
8282 4 2 8288 2060 lib/vsprintf.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vscnprintf() should return 0 if @size is == 0. Update the comment for it,
as @size is unsigned.
This change based on the code of commit
b903c0b889 ("lib: fix scnprintf() if @size
is == 0") moves the real fix into vscnprinf() from scnprintf() and makes
scnprintf() call vscnprintf(), thus avoid code duplication.
Signed-off-by: Anton Arapov <aarapov@redhat.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
scnprintf() should return 0 if @size is == 0. Update the comment for it,
as @size is unsigned.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The strict_strtoul() and strict_strtoull() functions used strlen() to
check argument's length in a situation where it wasn't strictly necessary
Signed-off-by: Michal Nazarewicz <mina86@mina86.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>
Add the ability to print a format and va_list from a structure pointer
Allows __dev_printk to be implemented as a single printk while
minimizing string space duplication.
%pV should not be used without some mechanism to verify the
format and argument use ala __attribute__(format (printf(...))).
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
USHORT_MAX/SHORT_MAX/SHORT_MIN.
- Make SHRT_MIN of type s16, not int, for consistency.
[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: Alexey Dobriyan <adobriyan@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>
Add a missing EXPORT_SYMBOL.
I must be the first person that wants to use this function :-)
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ef0658f3de changed precision
from int to s8.
There is existing kernel code that uses a larger precision.
An example from the audit code:
vsnprintf(...,..., " msg='%.1024s'", (char *)data);
which overflows precision and truncates to nothing.
Extending precision size fixes the audit system issue.
Other changes:
Change the size of the struct printf_spec.type from u16 to u8 so
sizeof(struct printf_spec) stays as small as possible.
Reorder the struct members so sizeof(struct printf_spec) remains 64 bits
without alignment holes.
Document the struct members a bit more.
Original-patch-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for resource windows. This is for bridge resources, i.e.,
regions where a bridge forwards transactions from the primary to the
secondary side.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add support for bus number resources. This is for bridges with a range of
bus numbers behind them.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
