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2017-11-17arch: Fix duplicates in Kconfig for parisc and sparcBabu Moger
Fix duplicates for sparc and parisc. This was due these following commits. 1. commit 4c97a0c8fee3 ("arch: define CPU_BIG_ENDIAN for all fixed big endian archs") 2. commit 97d9f969161d ("arch/sparc: Define config parameter CPU_BIG_ENDIAN") 3. commit 74ad3d28af21 ("parisc: Define CONFIG_CPU_BIG_ENDIAN") Remove duplicates. Signed-off-by: Babu Moger <babu.moger@oracle.com> Signed-off-by: Helge Deller <deller@gmx.de>
2017-11-17parisc: Add CPU topology supportHelge Deller
Add topology support, including multi-core scheduler support on PA8800/PA8900 CPUs and enhanced output in /proc/cpuinfo, e.g. lscpu now reports on a single-socket, dual-core machine: Architecture: parisc64 CPU(s): 2 On-line CPU(s) list: 0,1 Thread(s) per core: 1 Core(s) per socket: 2 Socket(s): 1 CPU family: PA-RISC 2.0 Model name: PA8800 (Mako) Signed-off-by: Helge Deller <deller@gmx.de>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-22parisc: Reintroduce option to gzip-compress the kernelHelge Deller
By adding the feature to build the kernel as self-extracting executeable, the possibility to simply compress the kernel with gzip was lost. This patch now reintroduces this possibilty again and leaves it up to the user to decide how the kernel should be built. The palo bootloader is able to natively load both formats. Signed-off-by: Helge Deller <deller@gmx.de>
2017-09-08arch: define CPU_BIG_ENDIAN for all fixed big endian archsBabu Moger
Patch series "Define CPU_BIG_ENDIAN or warn for inconsistencies", v3. While working on enabling queued rwlock on SPARC, found this following code in include/asm-generic/qrwlock.h which uses CONFIG_CPU_BIG_ENDIAN to clear a byte. static inline u8 *__qrwlock_write_byte(struct qrwlock *lock) { return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN); } Problem is many of the fixed big endian architectures don't define CPU_BIG_ENDIAN and clears the wrong byte. Define CPU_BIG_ENDIAN for all the fixed big endian architecture to fix it. Also found few more references of this config parameter in drivers/of/base.c drivers/of/fdt.c drivers/tty/serial/earlycon.c drivers/tty/serial/serial_core.c Be aware that this may cause regressions if someone has worked-around problems in the above code already. Remove the work-around. Here is our original discussion https://lkml.org/lkml/2017/5/24/620 Link: http://lkml.kernel.org/r/1499358861-179979-2-git-send-email-babu.moger@oracle.com Signed-off-by: Babu Moger <babu.moger@oracle.com> Suggested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Stafford Horne <shorne@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Simek <monstr@monstr.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-22parisc: Wire up support for self-extracting kernelHelge Deller
Signed-off-by: Helge Deller <deller@gmx.de>
2017-08-22parisc: Enable UBSAN supportHelge Deller
Signed-off-by: Helge Deller <deller@gmx.de>
2017-08-22parisc: PDT: Add full support for memory failure via Page Deallocation Table ↵Helge Deller
(PDT) This patch adds full support to read PDT info on all machine types. At bootup the PDT is read and bad memory excluded from usage via memblock_reserve(). Later in the boot process a kernel thread is started (kpdtd) which regularily checks firmare for new reported bad memory and tries to soft offline pages in case of correctable errors and to kill processes and exclude such memory in case of uncorrectable errors via memory_failure(). Signed-off-by: Helge Deller <deller@gmx.de>
2017-07-31parisc: Define CONFIG_CPU_BIG_ENDIANBabu Moger
While working on enabling queued rwlock on SPARC, found this following code in include/asm-generic/qrwlock.h which uses CONFIG_CPU_BIG_ENDIAN to clear a byte. static inline u8 *__qrwlock_write_byte(struct qrwlock *lock) { return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN); } Problem is many of the fixed big endian architectures don't define CPU_BIG_ENDIAN and clears the wrong byte. Define CPU_BIG_ENDIAN for parisc architecture to fix it. Signed-off-by: Babu Moger <babu.moger@oracle.com> Signed-off-by: Helge Deller <deller@gmx.de>
2017-04-26HAVE_ARCH_HARDENED_USERCOPY is unconditional nowAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-26CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional nowAl Viro
all architectures converted Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-02parisc: switch to RAW_COPY_USERAl Viro
... and remove dead declarations, while we are at it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-07arch: Move CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be commonLaura Abbott
There are multiple architectures that support CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX. These options also now have the ability to be turned off at runtime. Move these to an architecture independent location and make these options def_bool y for almost all of those arches. Signed-off-by: Laura Abbott <labbott@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-12-12parisc: Enable KASLRHelge Deller
Add missing code for userspace executable address randomization, e.g. applications compiled with the gcc -pie option. Signed-off-by: Helge Deller <deller@gmx.de>
2016-11-25parisc: Switch to generic sched_clock implementationHelge Deller
Drop the open-coded sched_clock() function and replace it by the provided GENERIC_SCHED_CLOCK implementation. We have seen quite some hung tasks in the past, which seem to be fixed by this patch. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v4.7+ Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
2016-10-07atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVEVineet Gupta
This came to light when implementing native 64-bit atomics for ARCv2. The atomic64 self-test code uses CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE to check whether atomic64_dec_if_positive() is available. It seems it was needed when not every arch defined it. However as of current code the Kconfig option seems needless - for CONFIG_GENERIC_ATOMIC64 it is auto-enabled in lib/Kconfig and a generic definition of API is present lib/atomic64.c - arches with native 64-bit atomics select it in arch/*/Kconfig and define the API in their headers So I see no point in keeping the Kconfig option Compile tested for: - blackfin (CONFIG_GENERIC_ATOMIC64) - x86 (!CONFIG_GENERIC_ATOMIC64) - ia64 Link: http://lkml.kernel.org/r/1473703083-8625-3-git-send-email-vgupta@synopsys.com Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ming Lin <ming.l@ssi.samsung.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07parisc: Drop bootmem and switch to memblockHelge Deller
Memblock is the standard kernel boot-time memory tracker/allocator. Use it instead of the bootmem allocator. This allows using kmemleak, CMA and other features. Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-06parisc: Add hardened usercopy featureHelge Deller
Add hardened usercopy checks to parisc architecture and clean up indenting. Signed-off-by: Helge Deller <deller@gmx.de>
2016-09-20parisc: Drop BROKEN_RODATA config optionHelge Deller
PARISC was the only architecture which selected the BROKEN_RODATA config option. Drop it and remove the special handling from init.h as well. Signed-off-by: Helge Deller <deller@gmx.de>
2016-08-30mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKSJosh Poimboeuf
There are three usercopy warnings which are currently being silenced for gcc 4.6 and newer: 1) "copy_from_user() buffer size is too small" compile warning/error This is a static warning which happens when object size and copy size are both const, and copy size > object size. I didn't see any false positives for this one. So the function warning attribute seems to be working fine here. Note this scenario is always a bug and so I think it should be changed to *always* be an error, regardless of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS. 2) "copy_from_user() buffer size is not provably correct" compile warning This is another static warning which happens when I enable __compiletime_object_size() for new compilers (and CONFIG_DEBUG_STRICT_USER_COPY_CHECKS). It happens when object size is const, but copy size is *not*. In this case there's no way to compare the two at build time, so it gives the warning. (Note the warning is a byproduct of the fact that gcc has no way of knowing whether the overflow function will be called, so the call isn't dead code and the warning attribute is activated.) So this warning seems to only indicate "this is an unusual pattern, maybe you should check it out" rather than "this is a bug". I get 102(!) of these warnings with allyesconfig and the __compiletime_object_size() gcc check removed. I don't know if there are any real bugs hiding in there, but from looking at a small sample, I didn't see any. According to Kees, it does sometimes find real bugs. But the false positive rate seems high. 3) "Buffer overflow detected" runtime warning This is a runtime warning where object size is const, and copy size > object size. All three warnings (both static and runtime) were completely disabled for gcc 4.6 with the following commit: 2fb0815c9ee6 ("gcc4: disable __compiletime_object_size for GCC 4.6+") That commit mistakenly assumed that the false positives were caused by a gcc bug in __compiletime_object_size(). But in fact, __compiletime_object_size() seems to be working fine. The false positives were instead triggered by #2 above. (Though I don't have an explanation for why the warnings supposedly only started showing up in gcc 4.6.) So remove warning #2 to get rid of all the false positives, and re-enable warnings #1 and #3 by reverting the above commit. Furthermore, since #1 is a real bug which is detected at compile time, upgrade it to always be an error. Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer needed. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Nilay Vaish <nilayvaish@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02parisc: Add <asm/hash.h>George Spelvin
PA-RISC is interesting; integer multiplies are implemented in the FPU, so are painful in the kernel. But it tries to be friendly to shift-and-add sequences for constant multiplies. __hash_32 is implemented using the same shift-and-add sequence as Microblaze, just scheduled for the PA7100. (It's 2-way superscalar but in-order, like the Pentium.) hash_64 was tricky, but a suggestion from Jason Thong allowed a good solution by breaking up the multiplier. After a lot of manual optimization, I found a 19-instruction sequence for the multiply that can be executed in 10 cycles using only 4 temporaries. (The PA8xxx can issue 4 instructions per cycle, but 2 must be ALU ops and 2 must be loads/stores. And the final add can't be paired.) An alternative considered, but ultimately not used, was Thomas Wang's 64-to-32-bit integer hash. At 12 instructions, it's smaller, but they're all sequentially dependent, so it has longer latency. https://web.archive.org/web/2011/http://www.concentric.net/~Ttwang/tech/inthash.htm http://burtleburtle.net/bob/hash/integer.html Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22parisc: Add native high-resolution sched_clock() implementationHelge Deller
Add a native implementation for the sched_clock() function which utilizes the processor-internal cycle counter (Control Register 16) as high-resolution time source. With this patch we now get much more fine-grained resolutions in various in-kernel time measurements (e.g. when viewing the function tracing logs), and probably a more accurate scheduling on SMP systems. There are a few specific implementation details in this patch: 1. On a 32bit kernel we emulate the higher 32bits of the required 64-bit resolution of sched_clock() by increasing a per-cpu counter at every wrap-around of the 32bit cycle counter. 2. In a SMP system, the cycle counters of the various CPUs are not syncronized (similiar to the TSC in a x86_64 system). To cope with this we define HAVE_UNSTABLE_SCHED_CLOCK and let the upper layers do the adjustment work. 3. Since we need HAVE_UNSTABLE_SCHED_CLOCK, we need to provide a cmpxchg64() function even on a 32-bit kernel. 4. A 64-bit SMP kernel which is started on a UP system will mark the sched_clock() implementation as "stable", which means that we don't expect any jumps in the returned counter. This is true because we then run only on one CPU. Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22parisc: Add ARCH_TRACEHOOK and regset supportHelge Deller
By adding TRACEHOOK support we now get a clean user interface to access registers via PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and PTRACE_SETFPREGS. The user-visible regset struct user_regs_struct and user_fp_struct are modelled similiar to x86 and can be accessed via PTRACE_GETREGSET. Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22parisc: Add syscall tracepoint supportHelge Deller
This patch adds support for the TIF_SYSCALL_TRACEPOINT on the parisc architecture. Basically, it calls the appropriate tracepoints on syscall entry and exit. Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-20lib/GCD.c: use binary GCD algorithm instead of EuclideanZhaoxiu Zeng
The binary GCD algorithm is based on the following facts: 1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2) 2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b) 3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b) Even on x86 machines with reasonable division hardware, the binary algorithm runs about 25% faster (80% the execution time) than the division-based Euclidian algorithm. On platforms like Alpha and ARMv6 where division is a function call to emulation code, it's even more significant. There are two variants of the code here, depending on whether a fast __ffs (find least significant set bit) instruction is available. This allows the unpredictable branches in the bit-at-a-time shifting loop to be eliminated. If fast __ffs is not available, the "even/odd" GCD variant is used. I use the following code to benchmark: #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <time.h> #include <unistd.h> #define swap(a, b) \ do { \ a ^= b; \ b ^= a; \ a ^= b; \ } while (0) unsigned long gcd0(unsigned long a, unsigned long b) { unsigned long r; if (a < b) { swap(a, b); } if (b == 0) return a; while ((r = a % b) != 0) { a = b; b = r; } return b; } unsigned long gcd1(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); for (;;) { a >>= __builtin_ctzl(a); if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd2(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; for (;;) { while (!(a & r)) a >>= 1; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } unsigned long gcd3(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); if (b == 1) return r & -r; for (;;) { a >>= __builtin_ctzl(a); if (a == 1) return r & -r; if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd4(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = { gcd0, gcd1, gcd2, gcd3, gcd4, }; #define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0])) #if defined(__x86_64__) #define rdtscll(val) do { \ unsigned long __a,__d; \ __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \ (val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \ } while(0) static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { unsigned long long start, end; unsigned long long ret; unsigned long gcd_res; rdtscll(start); gcd_res = gcd(a, b); rdtscll(end); if (end >= start) ret = end - start; else ret = ~0ULL - start + 1 + end; *res = gcd_res; return ret; } #else static inline struct timespec read_time(void) { struct timespec time; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time); return time; } static inline unsigned long long diff_time(struct timespec start, struct timespec end) { struct timespec temp; if ((end.tv_nsec - start.tv_nsec) < 0) { temp.tv_sec = end.tv_sec - start.tv_sec - 1; temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec; } else { temp.tv_sec = end.tv_sec - start.tv_sec; temp.tv_nsec = end.tv_nsec - start.tv_nsec; } return temp.tv_sec * 1000000000ULL + temp.tv_nsec; } static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { struct timespec start, end; unsigned long gcd_res; start = read_time(); gcd_res = gcd(a, b); end = read_time(); *res = gcd_res; return diff_time(start, end); } #endif static inline unsigned long get_rand() { if (sizeof(long) == 8) return (unsigned long)rand() << 32 | rand(); else return rand(); } int main(int argc, char **argv) { unsigned int seed = time(0); int loops = 100; int repeats = 1000; unsigned long (*res)[TEST_ENTRIES]; unsigned long long elapsed[TEST_ENTRIES]; int i, j, k; for (;;) { int opt = getopt(argc, argv, "n:r:s:"); /* End condition always first */ if (opt == -1) break; switch (opt) { case 'n': loops = atoi(optarg); break; case 'r': repeats = atoi(optarg); break; case 's': seed = strtoul(optarg, NULL, 10); break; default: /* You won't actually get here. */ break; } } res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops); memset(elapsed, 0, sizeof(elapsed)); srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); /* Do we have args? */ unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); unsigned long long min_elapsed[TEST_ENTRIES]; for (k = 0; k < repeats; k++) { for (i = 0; i < TEST_ENTRIES; i++) { unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]); if (k == 0 || min_elapsed[i] > tmp) min_elapsed[i] = tmp; } } for (i = 0; i < TEST_ENTRIES; i++) elapsed[i] += min_elapsed[i]; } for (i = 0; i < TEST_ENTRIES; i++) printf("gcd%d: elapsed %llu\n", i, elapsed[i]); k = 0; srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); for (i = 1; i < TEST_ENTRIES; i++) { if (res[j][i] != res[j][0]) break; } if (i < TEST_ENTRIES) { if (k == 0) { k = 1; fprintf(stderr, "Error:\n"); } fprintf(stderr, "gcd(%lu, %lu): ", a, b); for (i = 0; i < TEST_ENTRIES; i++) fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n"); } } if (k == 0) fprintf(stderr, "PASS\n"); free(res); return 0; } Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got: zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 10174 gcd1: elapsed 2120 gcd2: elapsed 2902 gcd3: elapsed 2039 gcd4: elapsed 2812 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9309 gcd1: elapsed 2280 gcd2: elapsed 2822 gcd3: elapsed 2217 gcd4: elapsed 2710 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9589 gcd1: elapsed 2098 gcd2: elapsed 2815 gcd3: elapsed 2030 gcd4: elapsed 2718 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9914 gcd1: elapsed 2309 gcd2: elapsed 2779 gcd3: elapsed 2228 gcd4: elapsed 2709 PASS [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable] Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-15Merge branch 'parisc-4.6-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc ftrace fixes from Helge Deller: "This is (most likely) the last pull request for v4.6 for the parisc architecture. It fixes the FTRACE feature for parisc, which is horribly broken since quite some time and doesn't even compile. This patch just fixes the bare minimum (it actually removes more lines than it adds), so that the function tracer works again on 32- and 64bit kernels. I've queued up additional patches on top of this patch which e.g. add the syscall tracer, but those have to wait for the merge window for v4.7." * 'parisc-4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix ftrace function tracer
2016-04-14parisc: Fix ftrace function tracerHelge Deller
Fix the FTRACE function tracer for 32- and 64-bit kernel. The former code was horribly broken. Reimplement most coding in assembly and utilize optimizations, e.g. put mcount() and ftrace_stub() into one L1 cacheline. Signed-off-by: Helge Deller <deller@gmx.de>
2016-03-31Merge branch 'parisc-4.6-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc fixes from Helge Deller: "Fix seccomp filter support and SIGSYS signals on compat kernel. Both patches are tagged for v4.5 stable kernel" * 'parisc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix and enable seccomp filter support parisc: Fix SIGSYS signals in compat case
2016-03-31parisc: Fix and enable seccomp filter supportHelge Deller
The seccomp filter support requires careful handling of task registers. This includes reloading of the return value (%r28) and proper syscall exit if secure_computing() returned -1. Additionally we need to sign-extend the syscall number from signed 32bit to signed 64bit in do_syscall_trace_enter() since the ptrace interface only allows storing 32bit values in compat mode. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v4.5
2016-03-23parisc: Use generic extable search and sort routinesHelge Deller
Switch to the generic extable search and sort routines which were introduced with commit a272858 from Ard Biesheuvel. This saves quite some memory in the vmlinux binary with the 64bit kernel. Signed-off-by: Helge Deller <deller@gmx.de>
2016-01-20dma-mapping: always provide the dma_map_ops based implementationChristoph Hellwig
Move the generic implementation to <linux/dma-mapping.h> now that all architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now that everyone supports them. [valentinrothberg@gmail.com: remove leftovers in Kconfig] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Helge Deller <deller@gmx.de> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Steven Miao <realmz6@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20parisc: convert to dma_map_opsChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Helge Deller <deller@gmx.de> Acked-by: Helge Deller <deller@gmx.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16Kconfig: remove HAVE_LATENCYTOP_SUPPORTWill Deacon
As illustrated by commit a3afe70b83fd ("[S390] latencytop s390 support."), HAVE_LATENCYTOP_SUPPORT is defined by an architecture to advertise an implementation of save_stack_trace_tsk. However, as of 9212ddb5eada ("stacktrace: provide save_stack_trace_tsk() weak alias") a dummy implementation is provided if STACKTRACE=y. Given that LATENCYTOP already depends on STACKTRACE_SUPPORT and selects STACKTRACE, we can remove HAVE_LATENCYTOP_SUPPORT altogether. Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: James Hogan <james.hogan@imgtec.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Helge Deller <deller@gmx.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22parisc: Add Huge Page and HUGETLBFS supportHelge Deller
This patch adds huge page support to allow userspace to allocate huge pages and to use hugetlbfs filesystem on 32- and 64-bit Linux kernels. A later patch will add kernel support to map kernel text and data on huge pages. The only requirement is, that the kernel needs to be compiled for a PA8X00 CPU (PA2.0 architecture). Older PA1.X CPUs do not support variable page sizes. 64bit Kernels are compiled for PA2.0 by default. Technically on parisc multiple physical huge pages may be needed to emulate standard 2MB huge pages. Signed-off-by: Helge Deller <deller@gmx.de>
2015-04-14parisc: expose number of page table levels on Kconfig levelKirill A. Shutemov
We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16parisc: hpux - Drop support for HP-UX binariesHelge Deller
This patch series drops the support for 32bit HP-UX binaries. The HP-UX compat layer has always been incomplete and it's unlikely that someone will ever implement it. Furthermore those two commits which enhance the compatibility of Linux on parisc to other architectures: f5a408d: parisc: Make EWOULDBLOCK be equal to EAGAIN on parisc 1f25df2: parisc: Reduce SIGRTMIN from 37 to 32 to behave like other Linux architectures basically make it impossible to implement the HP-UX support correctly. Signed-off-by: Helge Deller <deller@gmx.de>
2014-08-27parisc: Wire up seccomp, getrandom and memfd_create syscallsHelge Deller
With secure computing we only support the SECCOMP_MODE_STRICT mode for now. Signed-off-by: Helge Deller <deller@gmx.de>
2014-07-18parisc: ftrace: Remove check of obsolete variable function_trace_stopSteven Rostedt (Red Hat)
Nothing sets function_trace_stop to disable function tracing anymore. Remove the check for it in the arch code. Link: http://lkml.kernel.org/r/53B08317.7010501@gmx.de Cc: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-20Merge branch 'parisc-3.15-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc fixes from Helge Deller: "There are two patches in here: The first patch greatly improves latency and corrects the memory ordering in our light-weight atomic locking syscall. The second patch ratelimits printing of userspace segfaults in the same way as it's done on other platforms. This fixes a possible DOS on parisc since it prevents the syslog to grow too fast. For example, when the debian acl2 package was built on our debian buildd servers, this package produced lots of gigabytes in syslog in very short time and thus filled our harddisks, which then turned the server nearly completely unaccessible and unresponsive" * 'parisc-3.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Improve LWS-CAS performance parisc: ratelimit userspace segfault printing
2014-05-15parisc: ratelimit userspace segfault printingHelge Deller
Ratelimit printing of userspace segfaults and make it runtime configurable via the /proc/sys/debug/exception-trace variable. This should resolve syslog from growing way too fast and thus prevents possible system service attacks. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # 3.13+
2014-04-12Merge git://git.infradead.org/users/eparis/auditLinus Torvalds
Pull audit updates from Eric Paris. * git://git.infradead.org/users/eparis/audit: (28 commits) AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range audit: do not cast audit_rule_data pointers pointlesly AUDIT: Allow login in non-init namespaces audit: define audit_is_compat in kernel internal header kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c sched: declare pid_alive as inline audit: use uapi/linux/audit.h for AUDIT_ARCH declarations syscall_get_arch: remove useless function arguments audit: remove stray newline from audit_log_execve_info() audit_panic() call audit: remove stray newlines from audit_log_lost messages audit: include subject in login records audit: remove superfluous new- prefix in AUDIT_LOGIN messages audit: allow user processes to log from another PID namespace audit: anchor all pid references in the initial pid namespace audit: convert PPIDs to the inital PID namespace. pid: get pid_t ppid of task in init_pid_ns audit: rename the misleading audit_get_context() to audit_take_context() audit: Add generic compat syscall support audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL ...
2014-03-20audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALLAKASHI Takahiro
Currently AUDITSYSCALL has a long list of architecture depencency: depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT) || ALPHA) The purpose of this patch is to replace it with HAVE_ARCH_AUDITSYSCALL for simplicity. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> (arm) Acked-by: Richard Guy Briggs <rgb@redhat.com> (audit) Acked-by: Matt Turner <mattst88@gmail.com> (alpha) Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-23Kconfig: update flightly outdated CONFIG_SMP documentationRobert Graffham
Remove an outdated reference to "most personal computers" having only one CPU, and change the use of "singleprocessor" and "single processor" in CONFIG_SMP's documentation to "uniprocessor" across all arches where that documentation is present. Signed-off-by: Robert Graffham <psquid@psquid.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15Merge tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreamingLinus Torvalds
Pull Kconfig cleanups from Mark Salter: "Remove some unused config options from C6X and clean up PC_PARPORT dependencies. The latter was discussed here: https://lkml.org/lkml/2013/10/8/12" * tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming: c6x: remove unused COMMON_CLKDEV Kconfig parameter Kconfig cleanup (PARPORT_PC dependencies) x86: select ARCH_MIGHT_HAVE_PC_PARPORT unicore32: select ARCH_MIGHT_HAVE_PC_PARPORT sparc: select ARCH_MIGHT_HAVE_PC_PARPORT sh: select ARCH_MIGHT_HAVE_PC_PARPORT powerpc: select ARCH_MIGHT_HAVE_PC_PARPORT parisc: select ARCH_MIGHT_HAVE_PC_PARPORT mips: select ARCH_MIGHT_HAVE_PC_PARPORT microblaze: select ARCH_MIGHT_HAVE_PC_PARPORT m68k: select ARCH_MIGHT_HAVE_PC_PARPORT ia64: select ARCH_MIGHT_HAVE_PC_PARPORT arm: select ARCH_MIGHT_HAVE_PC_PARPORT alpha: select ARCH_MIGHT_HAVE_PC_PARPORT c6x: remove unused parameter in Kconfig
2013-11-15kernel: remove CONFIG_USE_GENERIC_SMP_HELPERSChristoph Hellwig
We've switched over every architecture that supports SMP to it, so remove the new useless config variable. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-07parisc: add kernel audit featureHelge Deller
Implement missing functions for parisc to provide kernel audit feature. Signed-off-by: Helge Deller <deller@gmx.de>
2013-10-23parisc: select ARCH_MIGHT_HAVE_PC_PARPORTMark Salter
Architectures which support CONFIG_PARPORT_PC should select ARCH_MIGHT_HAVE_PC_PARPORT. Signed-off-by: Mark Salter <msalter@redhat.com> CC: "James E.J. Bottomley" <jejb@parisc-linux.org> CC: Helge Deller <deller@gmx.de> CC: linux-parisc@vger.kernel.org
2013-09-13Remove GENERIC_HARDIRQ config optionMartin Schwidefsky
After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-07-04Merge branch 'kconfig-diet' from Dave HansenLinus Torvalds
Merge Kconfig menu diet patches from Dave Hansen: "I think the "Kernel Hacking" menu has gotten a bit out of hand. It is over 120 lines long on my system with everything enabled and options are scattered around it haphazardly. http://sr71.net/~dave/linux/kconfig-horror.png Let's try to introduce some sanity. This set takes that 120 lines down to 55 and makes it vastly easier to find some things. It's a start. This set stands on its own, but there is plenty of room for follow-up patches. The arch-specific debug options still end up getting stuck in the top-level "kernel hacking" menu. OPTIMIZE_INLINING, for instance, could obviously go in to the "compiler options" menu, but the fact that it is defined in arch/ in a separate Kconfig file keeps it on its own for the moment. The Signed-off-by's in here look funky. I changed employers while working on this set, so I have signoffs from both email addresses" * emailed patches from Dave Hansen <dave@sr71.net>: hang and lockup detection menu kconfig: consolidate printk options group locking debugging options consolidate compilation option configs consolidate runtime testing configs order memory debugging Kconfig options consolidate per-arch stack overflow debugging options