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* fs: stream_open - opener for stream-like files so that read and write can ↵Kirill Smelkov2019-04-061-0/+363
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | run simultaneously without deadlock Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f2655e3 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f2655 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2019-03-301-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc fixes from Andrew Morton: "22 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits) fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links fs: fs_parser: fix printk format warning checkpatch: add %pt as a valid vsprintf extension mm/migrate.c: add missing flush_dcache_page for non-mapped page migrate drivers/block/zram/zram_drv.c: fix idle/writeback string compare mm/page_isolation.c: fix a wrong flag in set_migratetype_isolate() mm/memory_hotplug.c: fix notification in offline error path ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK fs/proc/kcore.c: make kcore_modules static include/linux/list.h: fix list_is_first() kernel-doc mm/debug.c: fix __dump_page when mapping->host is not set mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified include/linux/hugetlb.h: convert to use vm_fault_t iommu/io-pgtable-arm-v7s: request DMA32 memory, and improve debugging mm: add support for kmem caches in DMA32 zone ocfs2: fix inode bh swapping mixup in ocfs2_reflink_inodes_lock mm/hotplug: fix offline undo_isolate_page_range() fs/open.c: allow opening only regular files during execve() mailmap: add Changbin Du mm/debug.c: add a cast to u64 for atomic64_read() ...
| * checkpatch: add %pt as a valid vsprintf extensionAlexandre Belloni2019-03-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4d42c44727a0 ("lib/vsprintf: Print time and date in human readable format via %pt") introduced a new extension, %pt. Add it in the list of valid extensions. Link: http://lkml.kernel.org/r/20190314203719.29130-1-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kconfig/[mn]conf: handle backspace (^H) keyChangbin Du2019-03-293-3/+5
| | | | | | | | | | | | | | | | | | | | Backspace is not working on some terminal emulators which do not send the key code defined by terminfo. Terminals either send '^H' (8) or '^?' (127). But currently only '^?' is handled. Let's also handle '^H' for those terminals. Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | kbuild: modversions: Fix relative CRC byte order interpretationFredrik Noring2019-03-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix commit 56067812d5b0 ("kbuild: modversions: add infrastructure for emitting relative CRCs") where CRCs are interpreted in host byte order rather than proper kernel byte order. The bug is conditional on CONFIG_MODULE_REL_CRCS. For example, when loading a BE module into a BE kernel compiled with a LE system, the error "disagrees about version of symbol module_layout" is produced. A message such as "Found checksum D7FA6856 vs module 5668FAD7" will be given with debug enabled, which indicates an obvious endian problem within __kcrctab within the kernel image. The general solution is to use the macro TO_NATIVE, as is done in similar cases throughout modpost.c. With this correction it has been verified that a BE kernel compiled with a LE system accepts BE modules. This change has also been verified with a LE kernel compiled with a LE system, in which case TO_NATIVE returns its value unmodified since the byte orders match. This is by far the common case. Fixes: 56067812d5b0 ("kbuild: modversions: add infrastructure for emitting relative CRCs") Signed-off-by: Fredrik Noring <noring@nocrew.org> Cc: stable@vger.kernel.org Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | scripts: coccinelle: Fix description of badty.cocciMichael Stefaniuc2019-03-281-1/+1
| | | | | | | | | | | | | | | | Summary was copy and pasted from array_size.cocci. Signed-off-by: Michael Stefaniuc <mstefani@mykolab.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | kbuild: strip whitespace in cmd_record_mcount findstringJoe Lawrence2019-03-281-5/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CC_FLAGS_FTRACE may contain trailing whitespace that interferes with findstring. For example, commit 6977f95e63b9 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer") introduced a change such that on my ppc64le box, CC_FLAGS_FTRACE="-pg -mprofile-kernel ". (Note the trailing space.) When cmd_record_mcount is now invoked, findstring fails as the ftrace flags were found at very end of _c_flags, without the trailing space. _c_flags=" ... -pg -mprofile-kernel" CC_FLAGS_FTRACE="-pg -mprofile-kernel " ^ findstring is looking for this extra space Remove the redundant whitespaces from CC_FLAGS_FTRACE in cmd_record_mcount to avoid this problem. [masahiro.yamada: This issue only happens in the released versions of GNU Make. CC_FLAGS_FTRACE will not contain the trailing space if you use the latest GNU Make, which contains commit b90fabc8d6f3 ("* NEWS: Do not insert a space during '+=' if the value is empty.") ] Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> (refactoring) Fixes: 6977f95e63b9 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer"). Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | coccinelle: put_device: reduce false positivesWen Yang2019-03-281-0/+1
|/ | | | | | | | | | Don't complain about a return when this function returns "&pdev->dev". Fixes: da9cfb87a44d ("coccinelle: semantic code search for missing put_device()") Reported-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kconfig: remove stale lxdialog/.gitignoreMasahiro Yamada2019-03-171-4/+0Star
| | | | | | | | | When this .gitignore was added, lxdialog was an independent hostprogs-y. Now that all objects in lxdialog/ are directly linked to mconf, the lxdialog is no longer generated. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: force all architectures except um to include mandatory-yMasahiro Yamada2019-03-171-0/+5
| | | | | | | | | | | | Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: warn redundant generic-yMasahiro Yamada2019-03-171-0/+6
| | | | | | | | | | | | | | | | | | | The generic-y is redundant under the following condition: - arch has its own implementation - the same header is added to generated-y - the same header is added to mandatory-y If a redundant generic-y is found, the warning like follows is displayed: scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h I fixed up arch Kbuild files found by this. Suggested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* Revert "modsign: Abort modules_install when signing fails"Douglas Anderson2019-03-171-1/+1
| | | | | | | | | | | | | | | This reverts commit caf6fe91ddf62a96401e21e9b7a07227440f4185. The commit was fine but is no longer needed as of commit 3a2429e1faf4 ("kbuild: change if_changed_rule for multi-line recipe"). Let's go back to using ";" to be consistent. For some discussion, see: https://lkml.kernel.org/r/CAK7LNASde0Q9S5GKeQiWhArfER4S4wL1=R_FW8q0++_X3T5=hQ@mail.gmail.com Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: deb-pkg: avoid implicit effectsArseny Maslennikov2019-03-171-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | * The man page for dpkg-source(1) notes: > -b, --build directory [format-specific-parameters] > Build a source package (--build since dpkg 1.17.14). > <...> > > dpkg-source will build the source package with the first > format found in this ordered list: the format indicated > with the --format command line option, the format > indicated in debian/source/format, “1.0”. The fallback > to “1.0” is deprecated and will be removed at some point > in the future, you should always document the desired > source format in debian/source/format. See section > SOURCE PACKAGE FORMATS for an extensive description of > the various source package formats. Thus it would be more foolproof to explicitly use 1.0 (as we always did) than to rely on dpkg-source's defaults. * In a similar vein, debian/rules is not made executable by mkdebian, and dpkg-source warns about that but still silently fixes the file. Let's be explicit once again. Signed-off-by: Arseny Maslennikov <ar@cs.msu.ru> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* coccinelle: semantic code search for missing put_device()Wen Yang2019-03-171-0/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The of_find_device_by_node() takes a reference to the underlying device structure, we should release that reference. The implementation of this semantic code search is: In a function, for a local variable returned by calling of_find_device_by_node(), a, if it is released by a function such as put_device()/of_dev_put()/platform_device_put() after the last use, it is considered that there is no reference leak; b, if it is passed back to the caller via dev_get_drvdata()/platform_get_drvdata()/get_device(), etc., the reference will be released in other functions, and the current function also considers that there is no reference leak; c, for the rest of the situation, the current function should release the reference by calling put_device, this code search will report the corresponding error message. By using this semantic code search, we have found some object reference leaks, such as: commit 11907e9d3533 ("ASoC: fsl-asoc-card: fix object reference leaks in fsl_asoc_card_probe") commit a12085d13997 ("mtd: rawnand: atmel: fix possible object reference leak") commit 11493f26856a ("mtd: rawnand: jz4780: fix possible object reference leak") There are still dozens of reference leaks in the current kernel code. Further, for the case of b, the object returned to other functions may also have a reference leak, we will continue to develop other cocci scripts to further check the reference leak. Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Julia Lawall <Julia.Lawall@lip6.fr> Reviewed-by: Markus Elfring <Markus.Elfring@web.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIGMasahiro Yamada2019-03-133-3/+3
| | | | | | | | | | | This will be a little more efficient since unset CONFIG options are stripped away from auto.conf, and we can hard-code the path to auto.conf since it is never overridden. include/config/kernel.release is generated before %pkg is run. So, it is guaranteed auto.conf is up-to-date. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddebMasahiro Yamada2019-03-131-13/+19
| | | | | | | | | | I think is_enabled() and if_enable_echo() in scripts/package/mkdebian are useful. builddeb also has many repetitive greps over the kernel config, so I borrowed the idea to clean it up. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: deb-pkg: add CONFIG_ prefix to kernel config optionsMasahiro Yamada2019-03-131-17/+17
| | | | | | | | | | | | This might be a kind of bike-shed, but I personally prefer grep'able code. I often do 'git grep CONFIG_FOO' instead of 'git grep FOO' when I want to know where that CONFIG option is used. This makes code longer, but I hope this is acceptable level. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG}Masahiro Yamada2019-03-132-16/+2Star
| | | | | | | | | | | | | | | As commit 423a8155facf ("kbuild: Fix reading of .config in link-vmlinux.sh") addressed, some shells fail to perform '.' if ${KCONFIG_CONFIG} does not contain a slash at all. Instead, we can source include/config/auto.conf, which obviously contain slashes, and we do not expect its file path overridden by a user. Perhaps, the performance might be slightly better since unset CONFIG options are stripped from include/config/auto.conf. scripts/setlocalversion already works this way. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: move archive command to scripts/Makefile.libMasahiro Yamada2019-03-132-5/+7
| | | | | | | | | scripts/Makefile.build and arch/s390/boot/Makefile use the same command (thin archiving with symbol table creation). Avoid the code duplication, and move it to scripts/Makefile.lib. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* modpost: always show verbose warning for section mismatchMasahiro Yamada2019-03-132-23/+5Star
| | | | | | | | | | | | | Unless CONFIG_DEBUG_SECTION_MISMATCH is enabled, modpost only shows the number of section mismatches. If you want to know the symbols causing the issue, you need to rebuild with CONFIG_DEBUG_SECTION_MISMATCH. It is tedious. I think it is fine to show annoying warning when a new section mismatch comes in. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* deb-pkg: generate correct build dependenciesRiku Voipio2019-03-131-1/+3
| | | | | | | | | | | | | | | | | | | bison/flex is now needed always for building for kconfig. Some build dependencies depend on kernel configuration, enable them as needed: - libelf-dev when UNWINDER_ORC is set - libssl-dev for SYSTEM_TRUSTED_KEYRING Since the libssl-dev is needed for extract_cert binary, denote with :native to install the libssl-dev for the build machines architecture, rather than for the architecture of the kernel being built. Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: maximilian attems <maks@stro.at> [masahiro.yamada: change 'flex' to 'flex | flex:native' ] Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* Merge tag 'kconfig-v5.1' of ↵Linus Torvalds2019-03-137-14/+44
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig updates from Masahiro Yamada: - rename lexer and parse files - fix 'Save as' menu of xconfig * tag 'kconfig-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: fix 'Save As' menu of xconfig kconfig: rename zconf.y to parser.y kconfig: rename zconf.l to lexer.l
| * kconfig: fix 'Save As' menu of xconfigMasahiro Yamada2019-03-112-7/+36
| | | | | | | | | | | | | | | | | | | | | | | | The 'Save As' menu of xconfig is not working; it always saves the kernel configuration into the default file irrespective of the file chosen in the dialog box. The 'Save' menu always writes into the default file, but it would make more sense to write into the file previously chosen by 'Load' or 'Save As'. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kconfig: rename zconf.y to parser.yMasahiro Yamada2019-02-134-5/+6
| | | | | | | | | | | | Use a more logical name. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kconfig: rename zconf.l to lexer.lMasahiro Yamada2019-02-133-4/+4
| | | | | | | | | | | | Use a more logical name. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | Merge tag 'kbuild-v5.1' of ↵Linus Torvalds2019-03-1118-165/+104Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - do not generate unneeded top-level built-in.a - let git ignore O= directory entirely - optimize scripts/kallsyms slightly - exclude DWARF info from *.s regardless of config options - fix GCC toolchain search path for Clang to prepare ld.lld support - do not generate modules.order when CONFIG_MODULES is disabled - simplify single target rules and remove VPATH for external module build - allow to add optional flags to dpkg-buildpackage when building deb-pkg - move some compiler option tests from Makefile to Kconfig - various Makefile cleanups * tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits) kbuild: remove scripts/basic/% build target kbuild: use -Werror=implicit-... instead of -Werror-implicit-... kbuild: clean up scripts/gcc-version.sh kbuild: remove cc-version macro kbuild: update comment block of scripts/clang-version.sh kbuild: remove commented-out INITRD_COMPRESS kbuild: move -gsplit-dwarf, -gdwarf-4 option tests to Kconfig kbuild: [bin]deb-pkg: add DPKG_FLAGS variable kbuild: move ".config not found!" message from Kconfig to Makefile kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing kbuild: simplify single target rules kbuild: remove empty rules for makefiles kbuild: make -r/-R effective in top Makefile for old Make versions kbuild: move tools_silent to a more relevant place kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig kbuild: refactor cc-cross-prefix implementation kbuild: hardcode genksyms path and remove GENKSYMS variable scripts/gdb: refactor rules for symlink creation kbuild: create symlink to vmlinux-gdb.py in scripts_gdb target scripts/gdb: do not descend into scripts/gdb from scripts ...
| * | kbuild: clean up scripts/gcc-version.shMasahiro Yamada2019-03-042-21/+8Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the Kconfig is the only user of this script, we can drop unneeded code. Remove the -p option, and stop prepending the output with zero, so that Kconfig can directly use the output from this script. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: remove cc-version macroMasahiro Yamada2019-03-041-4/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no more direct user of this macro; it is only used by cc-ifversion. Calling this macro is not efficient since it invokes the compiler to get the compiler version. CONFIG_GCC_VERSION is already calculated in the Kconfig stage, so Makefile can reuse it. Here is a note about the slight difference between cc-version and CONFIG_GCC_VERSION: When using Clang, cc-version is evaluated to '0402' because Clang defines __GNUC__ and __GNUC__MINOR__, and looks like GCC 4.2 in the version point of view. On the other hand, CONFIG_GCC_VERSION=0 when $(CC) is clang. There are currently two users of cc-ifversion: arch/mips/loongson64/Platform arch/powerpc/Makefile They are not affected by this change. The format of cc-version is <major><minor>, while CONFIG_GCC_VERSION <major><minor><patch>. I adjusted cc-ifversion for the difference of the number of digits. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: update comment block of scripts/clang-version.shMasahiro Yamada2019-03-041-7/+3Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 469cb7376c06 ("kconfig: add CC_IS_CLANG and CLANG_VERSION") changed the code, but missed to update the comment block. The -p option was gone, and the output is 5-digit (or 6-digit when Clang 10 is released). Update the comment now. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: [bin]deb-pkg: add DPKG_FLAGS variableKacper Kołodziej2019-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | DPKG_FLAGS variable lets user to add more flags to dpkg-buildpackage command in deb-pkg and bindeb-pkg. Signed-off-by: Kacper Kołodziej <kacper@kolodziej.it> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: move ".config not found!" message from Kconfig to MakefileMasahiro Yamada2019-02-271-13/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If you run "make" in a pristine source tree, currently Kbuild will start to build Kconfig to let it show the error message. It would be more straightforward to check it in Makefile and let it fail immediately. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: refactor cc-cross-prefix implementationMasahiro Yamada2019-02-271-8/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - $(word 1, <text>) is equivalent to $(firstword <text>) - hardcode "gcc" instead of $(CC) - minimize the shell script part A little more notes in case $(filter-out -%, ...) is not clear. arch/mips/Makefile passes prefixes depending on the configuration. CROSS_COMPILE := $(call cc-cross-prefix, $(tool-archpref)-linux- \ $(tool-archpref)-linux-gnu- $(tool-archpref)-unknown-linux-gnu-) In the Kconfig stage (e.g. when you run 'make defconfig'), neither CONFIG_32BIT nor CONFIG_64BIT is defined. So, $(tool-archpref) is empty. As a result, "-linux -linux-gnu- -unknown-linux-gnu" is passed into cc-cross-prefix. The command 'which' assumes arguments starting with a hyphen as command options, then emits the following messages: Illegal option -l Illegal option -l Illegal option -u I think it is strange to define CROSS_COMPILE depending on the CONFIG options since you need to feed $(CC) to Kconfig, but it is how MIPS Makefile currently works. Anyway, it would not hurt to filter-out invalid strings beforehand. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: hardcode genksyms path and remove GENKSYMS variableMasahiro Yamada2019-02-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The genksyms source was integrated into the kernel tree in 2003. I do not expect anybody still using the external /sbin/genksyms. Kbuild does not need to provide the ability to override GENKSYMS. Let's remove the GENKSYMS variable, and use the hardcoded path. Since it occurred in the pre-git era, I attached the commit message in case somebody is interested in the historical background. | Author: Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de> | Date: Wed Feb 19 04:17:28 2003 -0600 | | kbuild: [PATCH] put genksyms in scripts dir | | This puts genksyms into scripts/genksyms/. | | genksyms used to be maintained externally, though the only possible user | was the kernel build. Moving it into the kernel sources makes it easier to | keep it uptodate, like for example updating it to generate linker scripts | directly instead of postprocessing the generated header file fragments | with sed, as we do currently. | | Also, genksyms does not handle __typeof__, which needs to be fixed since | some of the exported symbol in the kernel are defined using __typeof__. | | (Rusty Russell/me) Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | scripts/gdb: refactor rules for symlink creationMasahiro Yamada2019-02-271-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gdb-scripts is not a real object, but (ab)used like a phony target. Rewrite the code in a more Kbuild-ish way. Add symlinks to extra-y and use if_changed. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
| * | scripts/gdb: do not descend into scripts/gdb from scriptsMasahiro Yamada2019-02-272-8/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, Kbuild descends from scripts/Makefile to scripts/gdb/Makefile just for creating symbolic links, but it does not need to do it so early. Merge the two descending paths to simplify the code. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
| * | kbuild: generate modules.order only when CONFIG_MODULES=yMasahiro Yamada2019-02-201-0/+2
| | | | | | | | | | | | | | | | | | | | | Do not generate pointless modules.order when the module support is disabled. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: pkg: use -f $(srctree)/Makefile to recurse to top MakefileMasahiro Yamada2019-02-204-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | '$(MAKE) KBUILD_SRC=' changes the working directory back and forth between objtree and srctree. It is better to recurse to the top-level Makefile directly. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: Disable extra debugging info in .s outputMasahiro Yamada2019-02-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modern gcc adds view assignments, reset assertion checking in .loc directives and a couple more additional debug markers, which clutters the asm output unnecessarily: For example: bsp_resume: .LFB3466: .loc 1 1868 1 is_stmt 1 view -0 .cfi_startproc .loc 1 1869 2 view .LVU73 # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) .loc 1 1869 14 is_stmt 0 view .LVU74 movq this_cpu(%rip), %rax # this_cpu, this_cpu movq 64(%rax), %rax # this_cpu.94_1->c_bsp_resume, _2 # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) .loc 1 1869 5 view .LVU75 testq %rax, %rax # _2 je .L8 #, .loc 1 1870 3 is_stmt 1 view .LVU76 movq $boot_cpu_data, %rdi #, jmp __x86_indirect_thunk_rax or .loc 2 57 9 view .LVU478 .loc 2 57 9 view .LVU479 .loc 2 57 9 view .LVU480 .loc 2 57 9 view .LVU481 .LBB1385: .LBB1383: .LBB1379: .LBB1377: .LBB1375: .loc 2 57 9 view .LVU482 .loc 2 57 9 view .LVU483 movl %edi, %edx # cpu, cpu .LVL87: .loc 2 57 9 is_stmt 0 view .LVU484 That MOV in there is drowned in debugging information and latter makes it hard to follow the asm. And that DWARF info is not really needed for asm output staring. Disable the debug information generation which clutters the asm output unnecessarily: bsp_resume: # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) movq this_cpu(%rip), %rax # this_cpu, this_cpu movq 64(%rax), %rax # this_cpu.94_1->c_bsp_resume, _2 # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) testq %rax, %rax # _2 je .L8 #, # arch/x86/kernel/cpu/common.c:1870: this_cpu->c_bsp_resume(&boot_cpu_data); movq $boot_cpu_data, %rdi #, jmp __x86_indirect_thunk_rax .L8: # arch/x86/kernel/cpu/common.c:1871: } rep ret .size bsp_resume, .-bsp_resume [ bp: write commit message. ] Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Borislav Petkov <bp@suse.de>
| * | kallsyms: include <asm/bitsperlong.h> instead of <asm/types.h>Masahiro Yamada2019-02-191-1/+1
| | | | | | | | | | | | | | | | | | | | | <asm/bitsperlong.h> is enough to include the definition of BITS_PER_LONG. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kallsyms: remove unneeded memset() callsMasahiro Yamada2019-02-191-3/+0Star
| | | | | | | | | | | | | | | | | | | | | Global variables in the .bss section are zeroed out before the program starts to run. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kallsyms: add static qualifiers where missingMasahiro Yamada2019-02-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following sparse warnings: scripts/kallsyms.c:65:5: warning: symbol 'token_profit' was not declared. Should it be static? scripts/kallsyms.c:68:15: warning: symbol 'best_table' was not declared. Should it be static? scripts/kallsyms.c:69:15: warning: symbol 'best_table_len' was not declared. Should it be static? Also, remove 'inline' from is_arm_mapping_symbol(). The compiler will inline it anyway when it is appropriate to do so. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: remove unnecessary in-subshell executionMasahiro Yamada2019-01-283-15/+14Star
| | | | | | | | | | | | | | | | | | | | | The commands surrounded by ( ) are executed in a subshell, but in most cases, we do not need to spawn an extra subshell. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: add real-prereqs shorthand for $(filter-out FORCE,$^)Masahiro Yamada2019-01-284-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In Kbuild, if_changed and friends must have FORCE as a prerequisite. Hence, $(filter-out FORCE,$^) or $(filter-out $(PHONY),$^) is a common idiom to get the names of all the prerequisites except phony targets. Add real-prereqs as a shorthand. Note: We cannot replace $(filter %.o,$^) in cmd_link_multi-m because $^ may include auto-generated dependencies from the .*.cmd file when a single object module is changed into a multi object module. Refer to commit 69ea912fda74 ("kbuild: remove unneeded link_multi_deps"). I added some comment to avoid accidental breakage. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Rob Herring <robh@kernel.org>
| * | kbuild: simplify rules of data compression with size appendingMasahiro Yamada2019-01-281-11/+7Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All the callers of size_append pass $(filter-out FORCE,$^). Move $(filter-out FORCE,$^) to the definition of size_append. This makes the callers cleaner because $(call ...) is unneeded for a macro with no argument. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: merge KBUILD_VMLINUX_{INIT,MAIN} into KBUILD_VMLINUX_OBJSMasahiro Yamada2019-01-281-18/+10Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The top Makefile does not need to export KBUILD_VMLINUX_INIT and KBUILD_VMLINUX_MAIN separately. Put every built-in.a into KBUILD_VMLINUX_OBJS. The order of $(head-y), $(init-y), $(core-y), ... is still retained. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * | kbuild: remove top-level built-in.aMasahiro Yamada2019-01-282-30/+8Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The symbol table in the final archive is unneeded; the linker does not require the symbol table after the --whole-archive option. Every object file in the archive is included in the link anyway. Pass thin archives from subdirectories directly to the linker, and remove the final archiving step. Fix up the document and comments as well. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicholas Piggin <npiggin@gmail.com>
| * | kbuild: skip 'addtree' and 'flags' magic for external module buildMasahiro Yamada2019-01-282-7/+10
| |/ | | | | | | | | | | | | | | When building an external module, $(obj) is the absolute path to it. The header search paths from ccflags-y etc. should not be tweaked. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | Merge tag 'platform-drivers-x86-v5.1-1' of ↵Linus Torvalds2019-03-102-1/+30
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.infradead.org/linux-platform-drivers-x86 Pull x86 platform driver updates from Darren Hart: - use MODULE_DEVICE_TABLE across several wmi drivers, keeping wmi_device_id and MODULE_ALIAS() declarations in sync - add several Ideapad models to the no_hw_rfkill list - add support for new Mellanox platforms, including new fan and LED functionality - address Dell keyboard backlight change event and power button release issues - update dell_rbu to use appropriate memory allocation mechanisms - several small fixes and Ice Lake support for intel_pmc_core - fix a suspend regression for Cherry Trail based devices in intel_int0002_vgpio - a few other routine fixes * tag 'platform-drivers-x86-v5.1-1' of git://git.infradead.org/linux-platform-drivers-x86: (50 commits) MAINTAINERS: Include mlxreg.h in Mellanox Platform Driver files platform/x86: ideapad-laptop: Add S130-14IGM to no_hw_rfkill list platform/x86: mlx-platform: Fix access mode for fan_dir attribute platform/x86: mlx-platform: Add UID LED for the next generation systems platform/x86: mlx-platform: Add extra CPLD for next generation systems platform/x86: wmi-bmof: use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() platform/x86: intel-wmi-thunderbolt: use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() platform/x86: huawei-wmi: use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() platform/x86: dell-wmi: use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() platform/x86: dell-wmi-descriptor: use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() platform/x86: dell-smbios-wmi: use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() platform/x86: wmi: add WMI support to MODULE_DEVICE_TABLE() platform/x86: wmi: move struct wmi_device_id to mod_devicetable.h modpost: file2alias: define size of alias platform/x86: touchscreen_dmi: Add info for the CHUWI Hi10 Air tablet platform/x86: ideapad-laptop: Add Ideapad 530S-14ARR to no_hw_rfkill list platform/x86: ideapad-laptop: Add Yoga C930 to no_hw_rfkill_list platform/x86: intel_pmc_core: Quirk to ignore XTAL shutdown platform/x86: intel_pmc_core: Add Package cstates residency info platform/x86: intel_pmc_core: Add ICL platform support ...
| * | platform/x86: wmi: add WMI support to MODULE_DEVICE_TABLE()Mattias Jacobsson2019-03-072-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel provides the macro MODULE_DEVICE_TABLE() where driver authors can specify their device type and their array of device_ids and thereby trigger the generation of the appropriate MODULE_ALIAS() output. This is opposed to having to specify one MODULE_ALIAS() for each device. The WMI device type is currently not supported. While using MODULE_DEVICE_TABLE() does increase the complexity as well as spreading out the implementation across the kernel, it does come with some benefits too; * It makes different drivers look more similar; if you can specify the array of device_ids any device type specific input to MODULE_ALIAS() will automatically be generated for you. * It helps each driver avoid keeping multiple versions of the same information in sync. That is, both the array of device_ids and the potential multitude of MODULE_ALIAS()'s. Add WMI support to MODULE_DEVICE_TABLE() by adding info about struct wmi_device_id in devicetable-offsets.c and add a WMI entry point in file2alias.c. The type argument for MODULE_DEVICE_TABLE(type, name) is wmi. Suggested-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Mattias Jacobsson <2pi@mok.nu> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
| * | platform/x86: wmi: move struct wmi_device_id to mod_devicetable.hMattias Jacobsson2019-03-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for adding WMI support to MODULE_DEVICE_TABLE() move the definition of struct wmi_device_id to mod_devicetable.h and inline guid_string in the struct. Changing guid_string to an inline char array changes the loop conditions when looping over an array of struct wmi_device_id. Therefore update wmi_dev_match()'s loop to check for an empty guid_string instead of a NULL pointer. Signed-off-by: Mattias Jacobsson <2pi@mok.nu> [dvhart: Move UUID_STRING_LEN define to this patch] Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>