- 22 Jul, 2016 6 commits
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Luis R. Rodriguez authored
Coccinelle supports reading .cocciconfig, the order of precedence for variables for .cocciconfig is as follows: o Your current user's home directory is processed first o Your directory from which spatch is called is processed next o The directory provided with the --dir option is processed last, if used Since coccicheck runs through make, it naturally runs from the kernel proper dir, as such the second rule above would be implied for picking up a .cocciconfig when using 'make coccicheck'. 'make coccicheck' also supports using M= targets.If you do not supply any M= target, it is assumed you want to target the entire kernel. The kernel coccicheck script has: if [ "$KBUILD_EXTMOD" = "" ] ; then OPTIONS="--dir $srctree $COCCIINCLUDE" else OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE" fi KBUILD_EXTMOD is set when an explicit target with M= is used. For both cases the spatch --dir argument is used, as such third rule applies when whether M= is used or not, and when M= is used the target directory can have its own .cocciconfig file. When M= is not passed as an argument to coccicheck the target directory is the same as the directory from where spatch was called. If not using the kernel's coccicheck target, keep the above precedence order logic of .cocciconfig reading. If using the kernel's coccicheck target, override any of the kernel's .coccicheck's settings using SPFLAGS. We help Coccinelle when used against Linux with a set of sensible defaults options for Linux with our own Linux .cocciconfig. This hints to coccinelle git can be used for 'git grep' queries over coccigrep. A timeout of 200 seconds should suffice for now. The options picked up by coccinelle when reading a .cocciconfig do not appear as arguments to spatch processes running on your system, to confirm what options will be used by Coccinelle run: spatch --print-options-only You can override with your own preferred index option by using SPFLAGS. Coccinelle supports both glimpse and idutils. Glimpse had historically provided the best performance, however recent benchmarks reveal idutils is performing just as well. Due to some recent fixes however you however will need at least coccinelle >= 1.0.6 if using idutils. Coccinelle carries a script scripts/idutils_index.sh which creates the idutils database with as follows: mkid -i C --output .id-utils.index If using just "--use-idutils" coccinelle expects your idutils database to be on the top level of the kernel as a file named ".id-utils.index". If you do not use this you can symlink your database file to it, or you can specify the database file following the "--use-idutils" argument. Examples: make SPFLAGS=--use-idutils coccicheck This assumes you have $srctree/.id-utils.index, where $srctree is the top level of the kernel. make SPFLAGS="--use-idutils /full-path/to/ID" coccicheck Here you specify the full path of the idutils ID database. Using .cocciconfig is possible, however given the order of precedence followed by Coccinelle, and since the kernel now carries its own .cocciconfig, you will need to use SPFLAGS to use idutils if desired. v4: o Recommend upgrade for using idutils with coccinelle due to some recent fixes. o Refer to using --print-options-only for testing what options are picked up by .cocciconfig reading. o Expand commit log considerably explaining *why* .cocconfig from two precedence rules are used when using coccicheck, and how to properly override these if needed. o Expand Documentation/coccinelle.txt v3: Expand commit log a bit more Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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Luis R. Rodriguez authored
When debugging (using --profile or --show-trying) you want to avoid supressing output, use --quiet instead. While at it, extend documentation for SPFLAGS use. For instance one can use: $ export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci $ make coccicheck DEBUG_FILE="poo.err" MODE=report SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c Expand Documentation/coccinelle.txt as well. v4: expand Documentation/coccinelle.txt v3: rebased, resolve conflicts, expand Documentation/coccinelle.txt v2: use egrep instead of the *"=--option"* check, this doesn't work for disjunctions. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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Luis R. Rodriguez authored
Enable to capture stderr via a DEBUG_FILE variable passed to coccicheck. You can now do: $ rm -f cocci.err $ export COCCI=scripts/coccinelle/free/kfree.cocci $ make coccicheck MODE=report DEBUG_FILE=cocci.err ... $ cat cocci.err This will be come more useful once we add support to use more things which would go into stderr, such as profiling. That will be done separately in another commit. Expand Documentation/coccinelle.txt with details. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Nicolas Palix <nicolas.palix@imag.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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Luis R. Rodriguez authored
Coccinelle has had parmap support since 1.0.2, this means it supports --jobs, enabling built-in multithreaded functionality, instead of needing one to script it out. Just look for --jobs in the help output to determine if this is supported and use it only if your number of processors detected is > 1. If parmap is enabled also enable the load balancing to be dynamic, so that if a thread finishes early we keep feeding it. stderr is currently sent to /dev/null, addressing a way to capture that will be addressed next. If --jobs is not supported we fallback to the old mechanism. We expect to deprecate the old mechanism as soon as we can get confirmation all users are ready. While at it propagate back into the shell script any coccinelle error code. When used in serialized mode where all cocci files are run this also stops processing if an error has occured. This lets us handle some errors in coccinelle cocci files and if they bail out we should inspect the errors. This will be more useful later to help annotate coccinelle version dependency requirements. This will let you run only SmPL files that your system supports. Extend Documentation/coccinelle.txt as well. As a small example, prior to this change, on an 8-core system: Before: $ export COCCI=scripts/coccinelle/free/kfree.cocci $ time make coccicheck MODE=report ... real 29m14.912s user 103m1.796s sys 0m4.464s After: real 16m22.435s user 128m30.060s sys 0m2.712s v4: o expand Documentation/coccinelle.txt to reflect parmap support info o update commit log to reflect what we actually do now with stderr o split out DEBUG_FILE use into another patch o detect number of CPUs and if its 1 then skip parmap support, note that if you still support parmap, but have 1 CPU you will also go through the new branches, so the old complex multithreaded process is skipped as well. v3: o move USE_JOBS to avoid being overriden v2: o redirect coccinelle stderr to /dev/null by default and only if DEBUG_FILE is used do we pass it to a file o fix typo of paramap/parmap Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Nicolas Palix <nicolas.palix@imag.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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Luis R. Rodriguez authored
SPFLAGS is set early, it means that any heuristics done on coccicheck cannot be overridden currently. Move SPFLAGS after OPTIONS and set this at the end. This lets you override any heuristics as coccinelle treats conflicts by only listening to the last option that makes sense. v3: this patch was added in the v3 series v4: Update Documentation/coccinelle.txt explaining how SPFLAGS works as well. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Nicolas Palix <nicolas.palix@imag.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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Luis R. Rodriguez authored
This has no functional changes. This is being done to enable us to later use spatch binary for some flag checking for certain features early on. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Nicolas Palix <nicolas.palix@imag.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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- 19 Jul, 2016 1 commit
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Wilfried Klaebe authored
On May 4th, Bjørn Mork provided patch 697bbc7b ("builddeb: include objtool binary in headers package"). However, that one only works if $srctree=$objtree, because the objtool binaries are not written to the srctree, but to the objtree. Signed-off-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de> Fixes: 697bbc7b ("builddeb: include objtool binary in headers package") Signed-off-by: Michal Marek <mmarek@suse.com>
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- 21 Jun, 2016 3 commits
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Yann Droneaud authored
krealloc() must not be used against devm_*() allocated memory regions: - if a bigger memory is to be allocated, krealloc() and __krealloc() could return a different pointer than the one given to them, creating a memory region which is not managed, thus it will not be automatically released on device removal. - if a bigger memory is to be allocated, krealloc() could kfree() the managed memory region which is passed to it. The old pointer is left registered as a resource for the device. On device removal, this dangling pointer will be used and an unrelated memory region could be released. - if the requested size is equal to 0, krealloc() can also just behave like kfree(). Here too, the old pointer is kept associated with the device. On device removal, this invalid pointer will be used and an unrelated memory region could be released. For all these reasons, krealloc() must not be used on a pointer returned by devm_*() functions. Cc: Tejun Heo <tj@kernel.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Signed-off-by: Michal Marek <mmarek@suse.com>
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Yann Droneaud authored
Updates free/devm_free.cocci to recognize functions added by: - commit 64c862a8 ('devres: add kernel standard devm_k.alloc functions') - commit e31108ca ('devres: introduce API "devm_kstrdup"') - commit 3046365b ('devres: introduce API "devm_kmemdup') - commit 43339bed ('devres: Add devm_get_free_pages API') - commit 75f2a4ea ('devres: Add devm_kasprintf and devm_kvasprintf API') See also Documentation/driver-model/devres.txt Cc: Joe Perches <joe@perches.com> Cc: Manish Badarkhe <badarkhe.manish@gmail.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Eli Billauer <eli.billauer@gmail.com> Cc: Himangi Saraogi <himangi774@gmail.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Signed-off-by: Michal Marek <mmarek@suse.com>
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Yann Droneaud authored
Since commit 3ef0e5ba ('slab: introduce kzfree()'), kfree() is no more the only function to be considered: kzfree() should be recognized too. In particular, kzfree() must not be called on memory allocated through devm_*() functions. Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Signed-off-by: Michal Marek <mmarek@suse.com>
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- 20 Jun, 2016 2 commits
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Deepa Dinamani authored
Documentation/coccinelle.txt suggests using the SPFLAGS make variable to pass additional options to spatch. Reorder the way SPFLAGS is added to FLAGS, to allow for options in the SPFLAGS to override the default --very-quiet option. Similarly, rearrage the FLAGS for org or report mode. This allows for overriding of the default --no-show-diff option through SPFLAGS. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Gilles Muller <Gilles.Muller@lip6.fr> Acked-by: Nicolas Palix <nicolas.palix@imag.fr> Acked-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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Vaishali Thakkar authored
Add new rules to detect the cases where sizeof is used in function calls as a argument. Also, for the patch mode third rule should behave same as second rule with arguments reversed. So, change that as well. Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Michal Marek <mmarek@suse.com>
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- 29 May, 2016 3 commits
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Linus Torvalds authored
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George Spelvin authored
The self-test was updated to cover zero-length strings; the function needs to be updated, too. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: George Spelvin <linux@sciencehorizons.net> Fixes: fcfd2fbf ("fs/namei.c: Add hashlen_string() function") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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George Spelvin authored
The original name was simply hash_string(), but that conflicted with a function with that name in drivers/base/power/trace.c, and I decided that calling it "hashlen_" was better anyway. But you have to do it in two places. [ This caused build errors for architectures that don't define CONFIG_DCACHE_WORD_ACCESS - Linus ] Signed-off-by: George Spelvin <linux@sciencehorizons.net> Reported-by: Guenter Roeck <linux@roeck-us.net> Fixes: fcfd2fbf ("fs/namei.c: Add hashlen_string() function") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- 28 May, 2016 25 commits
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Mikulas Patocka authored
The HPFS filesystem used generic_show_options to produce string that is displayed in /proc/mounts. However, there is a problem that the options may disappear after remount. If we mount the filesystem with option1 and then remount it with option2, /proc/mounts should show both option1 and option2, however it only shows option2 because the whole option string is replaced with replace_mount_options in hpfs_remount_fs. To fix this bug, implement the hpfs_show_options function that prints options that are currently selected. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mikulas Patocka authored
Commit c8f33d0b ("affs: kstrdup() memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: c8f33d0b ("affs: kstrdup() memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mikulas Patocka authored
Commit ce657611 ("hpfs: kstrdup() out of memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: ce657611 ("hpfs: kstrdup() out of memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds authored
Pull more MIPS updates from Ralf Baechle: "This is the secondnd batch of MIPS patches for 4.7. Summary: CPS: - Copy EVA configuration when starting secondary VPs. EIC: - Clear Status IPL. Lasat: - Fix a few off by one bugs. lib: - Mark intrinsics notrace. Not only are the intrinsics uninteresting, it would cause infinite recursion. MAINTAINERS: - Add file patterns for MIPS BRCM device tree bindings. - Add file patterns for mips device tree bindings. MT7628: - Fix MT7628 pinmux typos. - wled_an pinmux gpio. - EPHY LEDs pinmux support. Pistachio: - Enable KASLR VDSO: - Build microMIPS VDSO for microMIPS kernels. - Fix aliasing warning by building with `-fno-strict-aliasing' for debugging but also tracing them might result in recursion. Misc: - Add missing FROZEN hotplug notifier transitions. - Fix clk binding example for varioius PIC32 devices. - Fix cpu interrupt controller node-names in the DT files. - Fix XPA CPU feature separation. - Fix write_gc0_* macros when writing zero. - Add inline asm encoding helpers. - Add missing VZ accessor microMIPS encodings. - Fix little endian microMIPS MSA encodings. - Add 64-bit HTW fields and fix its configuration. - Fix sigreturn via VDSO on microMIPS kernel. - Lots of typo fixes. - Add definitions of SegCtl registers and use them" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (49 commits) MIPS: Add missing FROZEN hotplug notifier transitions MIPS: Build microMIPS VDSO for microMIPS kernels MIPS: Fix sigreturn via VDSO on microMIPS kernel MIPS: devicetree: fix cpu interrupt controller node-names MIPS: VDSO: Build with `-fno-strict-aliasing' MIPS: Pistachio: Enable KASLR MIPS: lib: Mark intrinsics notrace MIPS: Fix 64-bit HTW configuration MIPS: Add 64-bit HTW fields MAINTAINERS: Add file patterns for mips device tree bindings MAINTAINERS: Add file patterns for mips brcm device tree bindings MIPS: Simplify DSP instruction encoding macros MIPS: Add missing tlbinvf/XPA microMIPS encodings MIPS: Fix little endian microMIPS MSA encodings MIPS: Add missing VZ accessor microMIPS encodings MIPS: Add inline asm encoding helpers MIPS: Spelling fix lets -> let's MIPS: VR41xx: Fix typo MIPS: oprofile: Fix typo MIPS: math-emu: Fix typo ...
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Guenter Roeck authored
Various builds (such as i386:allmodconfig) fail with fs/binfmt_aout.c:133:2: error: expected identifier or '(' before 'return' fs/binfmt_aout.c:134:1: error: expected identifier or '(' before '}' token [ Oops. My bad, I had stupidly thought that "allmodconfig" covered this on x86-64 too, but it obviously doesn't. Egg on my face. - Linus ] Fixes: 5d22fc25 ("mm: remove more IS_ERR_VALUE abuses") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://ftp.sciencehorizons.net/linuxLinus Torvalds authored
Pull string hash improvements from George Spelvin: "This series does several related things: - Makes the dcache hash (fs/namei.c) useful for general kernel use. (Thanks to Bruce for noticing the zero-length corner case) - Converts the string hashes in <linux/sunrpc/svcauth.h> to use the above. - Avoids 64-bit multiplies in hash_64() on 32-bit platforms. Two 32-bit multiplies will do well enough. - Rids the world of the bad hash multipliers in hash_32. This finishes the job started in commit 689de1d6 ("Minimal fix-up of bad hashing behavior of hash_64()") The vast majority of Linux architectures have hardware support for 32x32-bit multiply and so derive no benefit from "simplified" multipliers. The few processors that do not (68000, h8/300 and some models of Microblaze) have arch-specific implementations added. Those patches are last in the series. - Overhauls the dcache hash mixing. The patch in commit 0fed3ac8 ("namei: Improve hash mixing if CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion. Replaced with a much more careful design that's simultaneously faster and better. (My own invention, as there was noting suitable in the literature I could find. Comments welcome!) - Modify the hash_name() loop to skip the initial HASH_MIX(). This would let us salt the hash if we ever wanted to. - Sort out partial_name_hash(). The hash function is declared as using a long state, even though it's truncated to 32 bits at the end and the extra internal state contributes nothing to the result. And some callers do odd things: - fs/hfs/string.c only allocates 32 bits of state - fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes - Modify bytemask_from_count to handle inputs of 1..sizeof(long) rather than 0..sizeof(long)-1. This would simplify users other than full_name_hash" Special thanks to Bruce Fields for testing and finding bugs in v1. (I learned some humbling lessons about "obviously correct" code.) On the arch-specific front, the m68k assembly has been tested in a standalone test harness, I've been in contact with the Microblaze maintainers who mostly don't care, as the hardware multiplier is never omitted in real-world applications, and I haven't heard anything from the H8/300 world" * 'hash' of git://ftp.sciencehorizons.net/linux: h8300: Add <asm/hash.h> microblaze: Add <asm/hash.h> m68k: Add <asm/hash.h> <linux/hash.h>: Add support for architecture-specific functions fs/namei.c: Improve dcache hash function Eliminate bad hash multipliers from hash_32() and hash_64() Change hash_64() return value to 32 bits <linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string() fs/namei.c: Add hashlen_string() function Pull out string hash to <linux/stringhash.h>
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George Spelvin authored
This will improve the performance of hash_32() and hash_64(), but due to complete lack of multi-bit shift instructions on H8, performance will still be bad in surrounding code. Designing H8-specific hash algorithms to work around that is a separate project. (But if the maintainers would like to get in touch...) Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: uclinux-h8-devel@lists.sourceforge.jp
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George Spelvin authored
Microblaze is an FPGA soft core that can be configured various ways. If it is configured without a multiplier, the standard __hash_32() will require a call to __mulsi3, which is a slow software loop. Instead, use a shift-and-add sequence for the constant multiply. GCC knows how to do this, but it's not as clever as some. Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Alistair Francis <alistair.francis@xilinx.com> Cc: Michal Simek <michal.simek@xilinx.com>
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George Spelvin authored
This provides a multiply by constant GOLDEN_RATIO_32 = 0x61C88647 for the original mc68000, which lacks a 32x32-bit multiply instruction. Yes, the amount of optimization effort put in is excessive. :-) Shift-add chain found by Yevgen Voronenko's Hcub algorithm at http://spiral.ece.cmu.edu/mcm/gen.htmlSigned-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Philippe De Muyter <phdm@macq.eu> Cc: linux-m68k@lists.linux-m68k.org
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George Spelvin authored
This is just the infrastructure; there are no users yet. This is modelled on CONFIG_ARCH_RANDOM; a CONFIG_ symbol declares the existence of <asm/hash.h>. That file may define its own versions of various functions, and define HAVE_* symbols (no CONFIG_ prefix!) to suppress the generic ones. Included is a self-test (in lib/test_hash.c) that verifies the basics. It is NOT in general required that the arch-specific functions compute the same thing as the generic, but if a HAVE_* symbol is defined with the value 1, then equality is tested. Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Philippe De Muyter <phdm@macq.eu> Cc: linux-m68k@lists.linux-m68k.org Cc: Alistair Francis <alistai@xilinx.com> Cc: Michal Simek <michal.simek@xilinx.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: uclinux-h8-devel@lists.sourceforge.jp
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George Spelvin authored
Patch 0fed3ac8 improved the hash mixing, but the function is slower than necessary; there's a 7-instruction dependency chain (10 on x86) each loop iteration. Word-at-a-time access is a very tight loop (which is good, because link_path_walk() is one of the hottest code paths in the entire kernel), and the hash mixing function must not have a longer latency to avoid slowing it down. There do not appear to be any published fast hash functions that: 1) Operate on the input a word at a time, and 2) Don't need to know the length of the input beforehand, and 3) Have a single iterated mixing function, not needing conditional branches or unrolling to distinguish different loop iterations. One of the algorithms which comes closest is Yann Collet's xxHash, but that's two dependent multiplies per word, which is too much. The key insights in this design are: 1) Barring expensive ops like multiplies, to diffuse one input bit across 64 bits of hash state takes at least log2(64) = 6 sequentially dependent instructions. That is more cycles than we'd like. 2) An operation like "hash ^= hash << 13" requires a second temporary register anyway, and on a 2-operand machine like x86, it's three instructions. 3) A better use of a second register is to hold a two-word hash state. With careful design, no temporaries are needed at all, so it doesn't increase register pressure. And this gets rid of register copying on 2-operand machines, so the code is smaller and faster. 4) Using two words of state weakens the requirement for one-round mixing; we now have two rounds of mixing before cancellation is possible. 5) A two-word hash state also allows operations on both halves to be done in parallel, so on a superscalar processor we get more mixing in fewer cycles. I ended up using a mixing function inspired by the ChaCha and Speck round functions. It is 6 simple instructions and 3 cycles per iteration (assuming multiply by 9 can be done by an "lea" instruction): x ^= *input++; y ^= x; x = ROL(x, K1); x += y; y = ROL(y, K2); y *= 9; Not only is this reversible, two consecutive rounds are reversible: if you are given the initial and final states, but not the intermediate state, it is possible to compute both input words. This means that at least 3 words of input are required to create a collision. (It also has the property, used by hash_name() to avoid a branch, that it hashes all-zero to all-zero.) The rotate constants K1 and K2 were found by experiment. The search took a sample of random initial states (I used 1023) and considered the effect of flipping each of the 64 input bits on each of the 128 output bits two rounds later. Each of the 8192 pairs can be considered a biased coin, and adding up the Shannon entropy of all of them produces a score. The best-scoring shifts also did well in other tests (flipping bits in y, trying 3 or 4 rounds of mixing, flipping all 64*63/2 pairs of input bits), so the choice was made with the additional constraint that the sum of the shifts is odd and not too close to the word size. The final state is then folded into a 32-bit hash value by a less carefully optimized multiply-based scheme. This also has to be fast, as pathname components tend to be short (the most common case is one iteration!), but there's some room for latency, as there is a fair bit of intervening logic before the hash value is used for anything. (Performance verified with "bonnie++ -s 0 -n 1536:-2" on tmpfs. I need a better benchmark; the numbers seem to show a slight dip in performance between 4.6.0 and this patch, but they're too noisy to quote.) Special thanks to Bruce fields for diligent testing which uncovered a nasty fencepost error in an earlier version of this patch. [checkpatch.pl formatting complaints noted and respectfully disagreed with.] Signed-off-by: George Spelvin <linux@sciencehorizons.net> Tested-by: J. Bruce Fields <bfields@redhat.com>
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George Spelvin authored
The "simplified" prime multipliers made very bad hash functions, so get rid of them. This completes the work of 689de1d6. To avoid the inefficiency which was the motivation for the "simplified" multipliers, hash_64() on 32-bit systems is changed to use a different algorithm. It makes two calls to hash_32() instead. drivers/media/usb/dvb-usb-v2/af9015.c uses the old GOLDEN_RATIO_PRIME_32 for some horrible reason, so it inherits a copy of the old definition. Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Antti Palosaari <crope@iki.fi> Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
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George Spelvin authored
That's all that's ever asked for, and it makes the return type of hash_long() consistent. It also allows (upcoming patch) an optimized implementation of hash_64 on 32-bit machines. I tried adding a BUILD_BUG_ON to ensure the number of bits requested was never more than 32 (most callers use a compile-time constant), but adding <linux/bug.h> to <linux/hash.h> breaks the tools/perf compiler unless tools/perf/MANIFEST is updated, and understanding that code base well enough to update it is too much trouble. I did the rest of an allyesconfig build with such a check, and nothing tripped. Signed-off-by: George Spelvin <linux@sciencehorizons.net>
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George Spelvin authored
Finally, the first use of previous two patches: eliminate the separate ad-hoc string hash functions in the sunrpc code. Now hash_str() is a wrapper around hash_string(), and hash_mem() is likewise a wrapper around full_name_hash(). Note that sunrpc code *does* call hash_mem() with a zero length, which is why the previous patch needed to handle that in full_name_hash(). (Thanks, Bruce, for finding that!) This also eliminates the only caller of hash_long which asks for more than 32 bits of output. The comment about the quality of hashlen_string() and full_name_hash() is jumping the gun by a few patches; they aren't very impressive now, but will be improved greatly later in the series. Signed-off-by: George Spelvin <linux@sciencehorizons.net> Tested-by: J. Bruce Fields <bfields@redhat.com> Acked-by: J. Bruce Fields <bfields@redhat.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: linux-nfs@vger.kernel.org
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George Spelvin authored
We'd like to make more use of the highly-optimized dcache hash functions throughout the kernel, rather than have every subsystem create its own, and a function that hashes basic null-terminated strings is required for that. (The name is to emphasize that it returns both hash and length.) It's actually useful in the dcache itself, specifically d_alloc_name(). Other uses in the next patch. full_name_hash() is also tweaked to make it more generally useful: 1) Take a "char *" rather than "unsigned char *" argument, to be consistent with hash_name(). 2) Handle zero-length inputs. If we want more callers, we don't want to make them worry about corner cases. Signed-off-by: George Spelvin <linux@sciencehorizons.net>
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George Spelvin authored
... so they can be used without the rest of <linux/dcache.h> The hashlen_* macros will make sense next patch. Signed-off-by: George Spelvin <linux@sciencehorizons.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fix from Wolfram Sang: "A fix for a regression introduced yesterday. The regression didn't show up here locally because I did not have PAGE_POISONING enabled. And buildbots discovered this only after it hit your tree. Thanks to Dan for the quick response" * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: dev: use after free in detach
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git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platformLinus Torvalds authored
Pull chrome platform updates from Olof Johansson "A handful of Chrome driver and binding changes this merge window: - a few patches to fix probing and configuration of pstore - a few patches adding Elan touchpad registration on a few devices - EC changes: a security fix dealing with max message sizes and addition of compat_ioctl support. - keyboard backlight control support There was also an accidential duplicate registration of trackpads on 'Leon', which was reverted just recently" * tag 'chrome-platform' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform: Revert "platform/chrome: chromeos_laptop: Add Leon Touch" platform/chrome: chromeos_laptop - Add Elan touchpad for Wolf platform/chrome: chromeos_laptop - Add elan trackpad option for C720 platform/chrome: cros_ec_dev - Populate compat_ioctl platform/chrome: cros_ec_lightbar - use name instead of ID to hide lightbar attributes platform/chrome: cros_ec_dev - Fix security issue platform/chrome: Add Chrome OS keyboard backlight LEDs support platform/chrome: use to_platform_device() platform/chrome: pstore: Move to larger record size. platform/chrome: pstore: probe for ramoops buffer using acpi platform/chrome: chromeos_laptop: Add Leon Touch
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/soundLinus Torvalds authored
Pull more sound updates from Takashi Iwai: "This is the second update round for 4.7-rc1. Most of changes are about the pending ASoC updates and fixes, including a few new drivers. Below are some highlights: ASoC: - New drivers for MAX98371 and TAS5720 - SPI support for TLV320AIC32x4, along with the module split - TDM support for STI Uniperf IPs - Remaining topology API fixes / updates HDA: - A couple of Dell quirks and new Realtek codec support" * tag 'sound-4.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (63 commits) ALSA: hda - Fix headset mic detection problem for one Dell machine spi: spi-ep93xx: Fix the PTR_ERR() argument ALSA: hda/realtek - Add support for ALC295/ALC3254 ASoC: kirkwood: fix build failure ALSA: hda - Fix headphone noise on Dell XPS 13 9360 ASoC: ak4642: Enable cache usage to fix crashes on resume ASoC: twl6040: Disconnect AUX output pads on digital mute ASoC: tlv320aic32x4: Properly implement the positive and negative pins into the mixers rcar: src: skip disabled-SRC nodes ASoC: max98371 Remove duplicate entry in max98371_reg ASoC: twl6040: Select LPPLL during standby ASoC: rsnd: don't use prohibited number to PDMACHCRn.SRS ASoC: simple-card: Add pm callbacks to platform driver ASoC: pxa: Fix module autoload for platform drivers ASoC: topology: Fix memory leak in widget creation ASoC: Add max98371 codec driver ASoC: rsnd: count .probe/.remove for rsnd_mod_call() ASoC: topology: Check size mismatch of ABI objects before parsing ASoC: topology: Check failure to create a widget ASoC: add support for TAS5720 digital amplifier ...
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git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pendingLinus Torvalds authored
Pull SCSI target updates from Nicholas Bellinger: "Here are the outstanding target pending updates for v4.7-rc1. The highlights this round include: - Allow external PR/ALUA metadata path be defined at runtime via top level configfs attribute (Lee) - Fix target session shutdown bug for ib_srpt multi-channel (hch) - Make TFO close_session() and shutdown_session() optional (hch) - Drop se_sess->sess_kref + convert tcm_qla2xxx to internal kref (hch) - Add tcm_qla2xxx endpoint attribute for basic FC jammer (Laurence) - Refactor iscsi-target RX/TX PDU encode/decode into common code (Varun) - Extend iscsit_transport with xmit_pdu, release_cmd, get_rx_pdu, validate_parameters, and get_r2t_ttt for generic ISO offload (Varun) - Initial merge of cxgb iscsi-segment offload target driver (Varun) The bulk of the changes are Chelsio's new driver, along with a number of iscsi-target common code improvements made by Varun + Co along the way" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (29 commits) iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race cxgbit: Use type ISCSI_CXGBIT + cxgbit tpg_np attribute iscsi-target: Convert transport drivers to signal rdma_shutdown iscsi-target: Make iscsi_tpg_np driver show/store use generic code tcm_qla2xxx Add SCSI command jammer/discard capability iscsi-target: graceful disconnect on invalid mapping to iovec target: need_to_release is always false, remove redundant check and kfree target: remove sess_kref and ->shutdown_session iscsi-target: remove usage of ->shutdown_session tcm_qla2xxx: introduce a private sess_kref target: make close_session optional target: make ->shutdown_session optional target: remove acl_stop target: consolidate and fix session shutdown cxgbit: add files for cxgbit.ko iscsi-target: export symbols iscsi-target: call complete on conn_logout_comp iscsi-target: clear tx_thread_active iscsi-target: add new offload transport type iscsi-target: use conn_transport->transport_type in text rsp ...
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git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdmaLinus Torvalds authored
Pull more rdma updates from Doug Ledford: "This is the second group of code for the 4.7 merge window. It looks large, but only in one sense. I'll get to that in a minute. The list of changes here breaks down as follows: - Dynamic counter infrastructure in the IB drivers This is a sysfs based code to allow free form access to the hardware counters RDMA devices might support so drivers don't need to code this up repeatedly themselves - SendOnlyFullMember multicast support - IB router support - A couple misc fixes - The big item on the list: hfi1 driver updates, plus moving the hfi1 driver out of staging There was a group of 15 patches in the hfi1 list that I thought I had in the first pull request but they weren't. So that added to the length of the hfi1 section here. As far as these go, everything but the hfi1 is pretty straight forward. The hfi1 is, if you recall, the driver that Al had complaints about how it used the write/writev interfaces in an overloaded fashion. The write portion of their interface behaved like the write handler in the IB stack proper and did bi-directional communications. The writev interface, on the other hand, only accepts SDMA request structures. The completions for those structures are sent back via an entirely different event mechanism. With the security patch, we put security checks on the write interface, however, we also knew they would be going away soon. Now, we've converted the write handler in the hfi1 driver to use ioctls from the IB reserved magic area for its bidirectional communications. With that change, Intel has addressed all of the items originally on their TODO when they went into staging (as well as many items added to the list later). As such, I moved them out, and since they were the last item in the staging/rdma directory, and I don't have immediate plans to use the staging area again, I removed the staging/rdma area. Because of the move out of staging, as well as a series of 5 patches in the hfi1 driver that removed code people thought should be done in a different way and was optional to begin with (a snoop debug interface, an eeprom driver for an eeprom connected directory to their hfi1 chip and not via an i2c bus, and a few other things like that), the line count, especially the removal count, is high" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (56 commits) staging/rdma: Remove the entire rdma subdirectory of staging IB/core: Make device counter infrastructure dynamic IB/hfi1: Fix pio map initialization IB/hfi1: Correct 8051 link parameter settings IB/hfi1: Update pkey table properly after link down or FM start IB/rdamvt: Fix rdmavt s_ack_queue sizing IB/rdmavt: Max atomic value should be a u8 IB/hfi1: Fix hard lockup due to not using save/restore spin lock IB/hfi1: Add tracing support for send with invalidate opcode IB/hfi1, qib: Add ieth to the packet header definitions IB/hfi1: Move driver out of staging IB/hfi1: Do not free hfi1 cdev parent structure early IB/hfi1: Add trace message in user IOCTL handling IB/hfi1: Remove write(), use ioctl() for user cmds IB/hfi1: Add ioctl() interface for user commands IB/hfi1: Remove unused user command IB/hfi1: Remove snoop/diag interface IB/hfi1: Remove EPROM functionality from data device IB/hfi1: Remove UI char device IB/hfi1: Remove multiple device cdev ...
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Benson Leung authored
This reverts commit bff3c624. Board "Leon" is otherwise known as "Toshiba CB35" and we already have the entry that supports that board as of this commit : 963cb6fa platform/chrome: chromeos_laptop - Add Toshiba CB35 Touch Remove this duplicate. Signed-off-by: Benson Leung <bleung@chromium.org> Signed-off-by: Olof Johansson <olof@lixom.net>
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Dan Carpenter authored
The call to put_i2c_dev() frees "i2c_dev" so there is a use after free when we call cdev_del(&i2c_dev->cdev). Fixes: d6760b14 ('i2c: dev: switch from register_chrdev to cdev API') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Anna-Maria Gleixner authored
The corresponding FROZEN hotplug notifier transitions used on suspend/resume are ignored. Therefore the switch case action argument is masked with the frozen hotplug notifier transition mask. Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: rt@linutronix.de Patchwork: https://patchwork.linux-mips.org/patch/13351/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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James Hogan authored
MicroMIPS kernels may be expected to run on microMIPS only cores which don't support the normal MIPS instruction set, so be sure to pass the -mmicromips flag through to the VDSO cflags. Fixes: ebb5e78c ("MIPS: Initial implementation of a VDSO") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.4.x- Patchwork: https://patchwork.linux-mips.org/patch/13349/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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