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2009-04-29vsprintf: introduce %pf format specifierFrederic Weisbecker
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>
2009-04-08printk: add support of hh length modifier for printkZhaolei
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>
2009-04-08printk: fix wrong format string iter for printkZhaolei
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>
2009-03-14vsprintf: unify the format decoding layer for its 3 users, cleanupVegard Nossum
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>
2009-03-14fix regression from "vsprintf: unify the format decoding layer for its 3 users"Vegard Nossum
Jeremy Fitzhardinge reported: > Change fef20d9c1380f04ba9492d6463148db07b413708, "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>
2009-03-10vsprintf: fix bug in negative value printingFrederic Weisbecker
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>
2009-03-06vsprintf: unify the format decoding layer for its 3 usersFrederic Weisbecker
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>
2009-03-06vsprintf: add binary printfLai Jiangshan
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>
2009-01-06strict_strto* is not strict enoughPavel Machek
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>
2009-01-03Make %p print '(null)' for NULL pointersLinus Torvalds
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>
2008-11-25aoe: remove private mac address format functionHarvey Harrison
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>
2008-11-03printk: ipv4 address digits printed in reverse orderHarvey Harrison
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>
2008-10-29printk: remove %p6 format specifier, fix up commentsHarvey Harrison
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29printk: add %I4, %I6, %i4, %i6 format specifiersHarvey Harrison
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>
2008-10-28printk: add %p6 format specifier for IPv6 addressesHarvey Harrison
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>
2008-10-27printk: add %pM format specifier for MAC addressesHarvey Harrison
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>
2008-10-20Implement %pR to print struct resource contentLinus Torvalds
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>
2008-10-16lib: remove defining macros for strict_strto??Harvey Harrison
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>
2008-10-16lib: trivial whitespace tidyHarvey Harrison
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>
2008-10-16lib: pull base-guessing logic to helper functionHarvey Harrison
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>
2008-10-16Add kerneldoc documentation for new printk format extensionsAndi Kleen
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>
2008-09-09lib: Correct printk %pF to work on all architecturesJames Bottomley
It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer formats" in commit 0fe1ef24f7bd0020f29ffe287dfdb9ead33ca0b2. 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>
2008-08-12lib/vsprintf.c: wrong conversion function usedYi Yang
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>
2008-07-06vsprintf: add support for '%pS' and '%pF' pointer formatsLinus Torvalds
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>
2008-07-06vsprintf: add infrastructure support for extended '%p' specifiersLinus Torvalds
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>
2008-07-06vsprintf: split out '%p' handling logicLinus Torvalds
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>
2008-07-06vsprintf: split out '%s' handling logicLinus Torvalds
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>
2008-02-23lib/vsprintf.c: fix bug omitting minus sign of numbers (module_param)Hoang-Nam Nguyen
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>
2008-02-09x86: trivial printk optimizationsDenys Vlasenko
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>
2008-02-08Add new string functions strict_strto* and convert kernel params to use themYi Yang
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>
2007-07-31lib: move kasprintf to a separate fileSam Ravnborg
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>
2007-07-16vsprintf.c: optimizing, part 2: base 10 conversion speedup, v2Denis Vlasenko
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>
2007-07-16vsprintf.c: optimizing, part 1 (easy and obvious stuff)Denis Vlasenko
* 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>
2007-05-08fix sscanf %n match at end of input stringJohannes Berg
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>
2007-04-30Add kvasprintf()Jeremy Fitzhardinge
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>
2007-02-12[PATCH] scnprintf(): fix a commentMartin Peschke
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>
2007-02-11[PATCH] Numerous fixes to kernel-doc info in source files.Robert P. J. Day
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>
2006-06-28Fix vsnprintf off-by-one bugLinus Torvalds
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>
2006-06-25[PATCH] Implement kasprintfJeremy Fitzhardinge
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[PATCH] Fix bounds check in vsnprintf, to allow for a 0 size and NULL bufferJeremy Fitzhardinge
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>
2005-10-30[PATCH] fix missing includesTim Schmielau
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>
2005-08-23[PATCH] %t... in vsnprintfAl Viro
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>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!