user/sven/linux.git/scripts, branch v5.1.14

kbuild: use more portable 'command -v' for cc-cross-prefix

2019-06-11T10:19:16Z

commit 913ab9780fc021298949cc5514d6255a008e69f9 upstream. To print the pathname that will be used by shell in the current environment, 'command -v' is a standardized way. [1] 'which' is also often used in scripts, but it is less portable. When I worked on commit bd55f96fa9fc ("kbuild: refactor cc-cross-prefix implementation"), I was eager to use 'command -v' but it did not work. (The reason is explained below.) I kept 'which' as before but got rid of '> /dev/null 2>&1' as I thought it was no longer needed. Sorry, I was wrong. It works well on my Ubuntu machine, but Alexey Brodkin reports noisy warnings on CentOS7 when 'which' fails to find the given command in the PATH environment. $ which foo which: no foo in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin) Given that behavior of 'which' depends on system (and it may not be installed by default), I want to try 'command -v' once again. The specification [1] clearly describes the behavior of 'command -v' when the given command is not found: Otherwise, no output shall be written and the exit status shall reflect that the name was not found. However, we need a little magic to use 'command -v' from Make. $(shell ...) passes the argument to a subshell for execution, and returns the standard output of the command. Here is a trick. GNU Make may optimize this by executing the command directly instead of forking a subshell, if no shell special characters are found in the command and omitting the subshell will not change the behavior. In this case, no shell special character is used. So, Make will try to run it directly. However, 'command' is a shell-builtin command, then Make would fail to find it in the PATH environment: $ make ARCH=m68k defconfig make: command: Command not found make: command: Command not found make: command: Command not found In fact, Make has a table of shell-builtin commands because it must ask the shell to execute them. Until recently, 'command' was missing in the table. This issue was fixed by the following commit: | commit 1af314465e5dfe3e8baa839a32a72e83c04f26ef | Author: Paul Smith | Date: Sun Nov 12 18:10:28 2017 -0500 | | * job.c: Add "command" as a known shell built-in. | | This is not a POSIX shell built-in but it's common in UNIX shells. | Reported by Nick Bowler . Because the latest release is GNU Make 4.2.1 in 2016, this commit is not included in any released versions. (But some distributions may have back-ported it.) We need to trick Make to spawn a subshell. There are various ways to do so: 1) Use a shell special character '~' as dummy $(shell : ~; command -v $(c)gcc) 2) Use a variable reference that always expands to the empty string (suggested by David Laight) $(shell command$${x:+} -v $(c)gcc) 3) Use redirect $(shell command -v $(c)gcc 2>/dev/null) I chose 3) to not confuse people. The stderr would not be polluted anyway, but it will provide extra safety, and is easy to understand. Tested on Make 3.81, 3.82, 4.0, 4.1, 4.2, 4.2.1 [1] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html Fixes: bd55f96fa9fc ("kbuild: refactor cc-cross-prefix implementation") Cc: linux-stable # 5.1 Reported-by: Alexey Brodkin Signed-off-by: Masahiro Yamada Tested-by: Alexey Brodkin Signed-off-by: Greg Kroah-Hartman

gcc-plugins: Fix build failures under Darwin host

2019-06-09T07:16:16Z

commit 7210e060155b9cf557fb13128353c3e494fa5ed3 upstream. The gcc-common.h file did not take into account certain macros that might have already been defined in the build environment. This updates the header to avoid redefining the macros, as seen on a Darwin host using gcc 4.9.2: HOSTCXX -fPIC scripts/gcc-plugins/arm_ssp_per_task_plugin.o - due to: scripts/gcc-plugins/gcc-common.h In file included from scripts/gcc-plugins/arm_ssp_per_task_plugin.c:3:0: scripts/gcc-plugins/gcc-common.h:153:0: warning: "__unused" redefined ^ In file included from /usr/include/stdio.h:64:0, from /Users/hns/Documents/Projects/QuantumSTEP/System/Library/Frameworks/System.framework/Versions-jessie/x86_64-apple-darwin15.0.0/gcc/arm-linux-gnueabi/bin/../lib/gcc/arm-linux-gnueabi/4.9.2/plugin/include/system.h:40, from /Users/hns/Documents/Projects/QuantumSTEP/System/Library/Frameworks/System.framework/Versions-jessie/x86_64-apple-darwin15.0.0/gcc/arm-linux-gnueabi/bin/../lib/gcc/arm-linux-gnueabi/4.9.2/plugin/include/gcc-plugin.h:28, from /Users/hns/Documents/Projects/QuantumSTEP/System/Library/Frameworks/System.framework/Versions-jessie/x86_64-apple-darwin15.0.0/gcc/arm-linux-gnueabi/bin/../lib/gcc/arm-linux-gnueabi/4.9.2/plugin/include/plugin.h:23, from scripts/gcc-plugins/gcc-common.h:9, from scripts/gcc-plugins/arm_ssp_per_task_plugin.c:3: /usr/include/sys/cdefs.h:161:0: note: this is the location of the previous definition ^ Reported-and-tested-by: "H. Nikolaus Schaller" Fixes: 189af4657186 ("ARM: smp: add support for per-task stack canaries") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

gcc-plugins: arm_ssp_per_task_plugin: Fix for older GCC < 6

2019-05-25T16:16:35Z

commit 259799ea5a9aa099a267f3b99e1f7078bbaf5c5e upstream. Use gen_rtx_set instead of gen_rtx_SET. The former is a wrapper macro that handles the difference between GCC versions implementing the latter. This fixes the following error on my system with g++ 5.4.0 as the host compiler HOSTCXX -fPIC scripts/gcc-plugins/arm_ssp_per_task_plugin.o scripts/gcc-plugins/arm_ssp_per_task_plugin.c:42:14: error: macro "gen_rtx_SET" requires 3 arguments, but only 2 given mask)), ^ scripts/gcc-plugins/arm_ssp_per_task_plugin.c: In function ‘unsigned int arm_pertask_ssp_rtl_execute()’: scripts/gcc-plugins/arm_ssp_per_task_plugin.c:39:20: error: ‘gen_rtx_SET’ was not declared in this scope emit_insn_before(gen_rtx_SET Signed-off-by: Chris Packham Fixes: 189af4657186 ("ARM: smp: add support for per-task stack canaries") Cc: stable@vger.kernel.org Tested-by: Douglas Anderson Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

Merge tag 'selinux-pr-20190429' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2019-04-30T15:38:02Z

Pull selinux fix from Paul Moore: "One small patch for the stable folks to fix a problem when building against the latest glibc. I'll be honest and say that I'm not really thrilled with the idea of sending this up right now, but Greg is a little annoyed so here I figured I would at least send this" * tag 'selinux-pr-20190429' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: use kernel linux/socket.h for genheaders and mdp

selinux: use kernel linux/socket.h for genheaders and mdp

2019-04-29T15:34:58Z

When compiling genheaders and mdp from a newer host kernel, the following error happens: In file included from scripts/selinux/genheaders/genheaders.c:18: ./security/selinux/include/classmap.h:238:2: error: #error New address family defined, please update secclass_map. #error New address family defined, please update secclass_map. ^~~~~ make[3]: *** [scripts/Makefile.host:107: scripts/selinux/genheaders/genheaders] Error 1 make[2]: *** [scripts/Makefile.build:599: scripts/selinux/genheaders] Error 2 make[1]: *** [scripts/Makefile.build:599: scripts/selinux] Error 2 make[1]: *** Waiting for unfinished jobs.... Instead of relying on the host definition, include linux/socket.h in classmap.h to have PF_MAX. Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara Acked-by: Stephen Smalley [PM: manually merge in mdp.c, subject line tweaks] Signed-off-by: Paul Moore

locking/atomics: Don't assume that scripts are executable

2019-04-19T12:21:43Z

patch(1) doesn't set the x bit on files. So if someone downloads and applies patch-4.21.xz, their kernel won't build. Fix that by executing /bin/sh. Signed-off-by: Andrew Morton Acked-by: Mark Rutland Cc: Boqun Feng Cc: Linus Torvalds Cc: Peter Zijlstra (Intel) Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Ingo Molnar

fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock

2019-04-06T17:01:55Z

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 Cc: Yongzhi Pan Cc: Jonathan Corbet Cc: David Vrabel Cc: Juergen Gross Cc: Miklos Szeredi Cc: Tejun Heo Cc: Kirill Tkhai Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: Julia Lawall Cc: Nikolaus Rath Cc: Han-Wen Nienhuys Signed-off-by: Kirill Smelkov Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

2019-03-29T23:02:28Z

Merge misc fixes from Andrew Morton: "22 fixes" * emailed patches from Andrew Morton : (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 extension

2019-03-29T17:01:37Z

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 Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kconfig/[mn]conf: handle backspace (^H) key

2019-03-29T13:48:01Z

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 Signed-off-by: Masahiro Yamada