# git rev-parse -q --verify 10dce8af34226d90fa56746a934f8da5dcdba3df^{commit}
10dce8af34226d90fa56746a934f8da5dcdba3df
already have revision, skipping fetch
# git checkout -q -f -B kisskb 10dce8af34226d90fa56746a934f8da5dcdba3df
# git clean -qxdf
# < git log -1
# commit 10dce8af34226d90fa56746a934f8da5dcdba3df
# Author: Kirill Smelkov <kirr@nexedi.com>
# Date:   Tue Mar 26 22:20:43 2019 +0000
# 
#     fs: stream_open - opener for stream-like files so that read and write can 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>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-ld --version
# < git log --format=%s --max-count=1 10dce8af34226d90fa56746a934f8da5dcdba3df
# < make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-allyesconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-  allyesconfig
# Added to kconfig CONFIG_BUILD_DOCSRC=n
# Added to kconfig CONFIG_MODULE_SIG=n
# yes \n | make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-allyesconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-  oldconfig
yes: standard output: Broken pipe
# make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-allyesconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-  
<stdin>:1478:2: warning: #warning syscall pidfd_send_signal not implemented [-Wcpp]
<stdin>:1481:2: warning: #warning syscall io_uring_setup not implemented [-Wcpp]
<stdin>:1484:2: warning: #warning syscall io_uring_enter not implemented [-Wcpp]
<stdin>:1487:2: warning: #warning syscall io_uring_register not implemented [-Wcpp]
/kisskb/src/kernel/events/ring_buffer.c: In function 'perf_output_begin_forward':
/kisskb/src/kernel/events/ring_buffer.c:237:1: warning: 'perf_output_begin_forward' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/ring_buffer.c: In function 'perf_output_begin_backward':
/kisskb/src/kernel/events/ring_buffer.c:243:1: warning: 'perf_output_begin_backward' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/ring_buffer.c: In function 'perf_output_begin':
/kisskb/src/kernel/events/ring_buffer.c:251:1: warning: 'perf_output_begin' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_log_throttle':
/kisskb/src/kernel/events/core.c:7691:1: warning: 'perf_log_throttle' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_swevent_hrtimer':
/kisskb/src/kernel/events/core.c:9398:1: warning: 'perf_swevent_hrtimer' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_log_itrace_start':
/kisskb/src/kernel/events/core.c:7933:1: warning: 'perf_log_itrace_start' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_read_event':
/kisskb/src/kernel/events/core.c:6599:1: warning: 'perf_event_read_event' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_task_output':
/kisskb/src/kernel/events/core.c:6879:1: warning: 'perf_event_task_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_bpf_output':
/kisskb/src/kernel/events/core.c:7825:1: warning: 'perf_event_bpf_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_ksymbol_output':
/kisskb/src/kernel/events/core.c:7736:1: warning: 'perf_event_ksymbol_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_mmap_output':
/kisskb/src/kernel/events/core.c:7237:1: warning: 'perf_event_mmap_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_namespaces_output':
/kisskb/src/kernel/events/core.c:7072:1: warning: 'perf_event_namespaces_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_comm_output':
/kisskb/src/kernel/events/core.c:6973:1: warning: 'perf_event_comm_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_switch_output':
/kisskb/src/kernel/events/core.c:7620:1: warning: 'perf_event_switch_output' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_event_aux_event':
/kisskb/src/kernel/events/core.c:7528:1: warning: 'perf_event_aux_event' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_log_lost_samples':
/kisskb/src/kernel/events/core.c:7561:1: warning: 'perf_log_lost_samples' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function 'perf_tp_event':
/kisskb/src/kernel/events/core.c:8572:1: warning: 'perf_tp_event' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/events/core.c: In function '___perf_sw_event':
/kisskb/src/kernel/events/core.c:8258:1: warning: '___perf_sw_event' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:187:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/afs/dynroot.c: In function 'afs_lookup_atcell':
/kisskb/src/fs/afs/dynroot.c:126:6: warning: 'len' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/atm/ambassador.c: In function 'do_loader_command':
/kisskb/src/drivers/atm/ambassador.c:1762:3: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct loader_block *'
/kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read':
/kisskb/src/drivers/base/regmap/regmap.c:2594:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write':
/kisskb/src/drivers/base/regmap/regmap.c:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/ata/ahci_qoriq.c: In function 'ahci_qoriq_hardreset':
/kisskb/src/include/asm-generic/io.h:232:15: warning: 'px_is' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/ata/ahci_qoriq.c:86:14: note: 'px_is' was declared here
/kisskb/src/include/asm-generic/io.h:232:15: warning: 'px_cmd' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/ata/ahci_qoriq.c:86:6: note: 'px_cmd' was declared here
/kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page':
/kisskb/src/mm/hugetlb.c:1435:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/sound/hda/hdac_regmap.c: In function 'hda_reg_write':
/kisskb/src/sound/hda/hdac_regmap.c:282:16: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/arch/s390/kernel/perf_cpum_sf.c: In function 'perf_push_sample':
/kisskb/src/arch/s390/kernel/perf_cpum_sf.c:1075:1: warning: 'perf_push_sample' uses dynamic stack allocation [enabled by default]
/kisskb/src/arch/s390/kernel/perf_cpum_cf_diag.c: In function 'cf_diag_push_sample':
/kisskb/src/arch/s390/kernel/perf_cpum_cf_diag.c:514:1: warning: 'cf_diag_push_sample' uses dynamic stack allocation [enabled by default]
/kisskb/src/fs/btrfs/ref-verify.c: In function 'process_extent_item.isra.2':
/kisskb/src/fs/btrfs/ref-verify.c:503:2: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/btrfs/ref-verify.c: In function 'process_leaf.isra.3':
/kisskb/src/fs/btrfs/ref-verify.c:555:2: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/mm/slub.c: In function 'deactivate_slab.isra.50':
/kisskb/src/mm/slub.c:2185:1: warning: 'deactivate_slab.isra.50' uses dynamic stack allocation [enabled by default]
/kisskb/src/mm/slub.c: In function 'unfreeze_partials.isra.51':
/kisskb/src/mm/slub.c:2253:1: warning: 'unfreeze_partials.isra.51' uses dynamic stack allocation [enabled by default]
/kisskb/src/mm/slub.c: In function 'get_partial_node.isra.52':
/kisskb/src/mm/slub.c:1892:1: warning: 'get_partial_node.isra.52' uses dynamic stack allocation [enabled by default]
/kisskb/src/mm/slub.c: In function '___slab_alloc':
/kisskb/src/mm/slub.c:2637:1: warning: '___slab_alloc' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_setup_act':
/kisskb/src/drivers/s390/scsi/zfcp_erp.c:262:2: warning: 'erp_action' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/mm/slub.c: In function '__slab_free':
/kisskb/src/mm/slub.c:2938:1: warning: '__slab_free' uses dynamic stack allocation [enabled by default]
/kisskb/src/fs/f2fs/file.c: In function 'f2fs_precache_extents':
/kisskb/src/fs/f2fs/file.c:2939:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/bridge/netfilter/ebtables.c: In function 'compat_copy_everything_to_user':
/kisskb/src/net/bridge/netfilter/ebtables.c:1855:1: warning: 'compat_copy_everything_to_user' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'query_info':
/kisskb/src/drivers/s390/net/ism_drv.c:84:1: warning: 'query_info' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'register_sba':
/kisskb/src/drivers/s390/net/ism_drv.c:111:1: warning: 'register_sba' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'register_ieq':
/kisskb/src/drivers/s390/net/ism_drv.c:140:1: warning: 'register_ieq' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_query_rgid':
/kisskb/src/drivers/s390/net/ism_drv.c:215:1: warning: 'ism_query_rgid' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_unregister_dmb':
/kisskb/src/drivers/s390/net/ism_drv.c:302:1: warning: 'ism_unregister_dmb' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_add_vlan_id':
/kisskb/src/drivers/s390/net/ism_drv.c:316:1: warning: 'ism_add_vlan_id' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_del_vlan_id':
/kisskb/src/drivers/s390/net/ism_drv.c:330:1: warning: 'ism_del_vlan_id' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_signal_ieq':
/kisskb/src/drivers/s390/net/ism_drv.c:358:1: warning: 'ism_signal_ieq' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_dev_init':
/kisskb/src/drivers/s390/net/ism_drv.c:492:1: warning: 'ism_dev_init' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/s390/net/ism_drv.c: In function 'ism_register_dmb':
/kisskb/src/drivers/s390/net/ism_drv.c:281:1: warning: 'ism_register_dmb' uses dynamic stack allocation [enabled by default]
/kisskb/src/net/bridge/br_device.c: In function 'br_get_stats64':
/kisskb/src/net/bridge/br_device.c:232:1: warning: 'br_get_stats64' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/smp.c: In function 'smp_call_function_single':
/kisskb/src/kernel/smp.c:307:1: warning: 'smp_call_function_single' uses dynamic stack allocation [enabled by default]
/kisskb/src/net/bridge/br_netlink.c: In function 'br_process_vlan_info':
/kisskb/src/net/bridge/br_netlink.c:591:10: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/crypto/chelsio/chtls/chtls_cm.c: In function 'wait_for_states.constprop.23':
/kisskb/src/drivers/crypto/chelsio/chtls/chtls_cm.c:406:1: warning: 'wait_for_states.constprop.23' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/rseq.c: In function 'rseq_ip_fixup':
/kisskb/src/kernel/rseq.c:249:1: warning: 'rseq_ip_fixup' uses dynamic stack allocation [enabled by default]
/kisskb/src/kernel/rseq.c: In function 'rseq_syscall':
/kisskb/src/kernel/rseq.c:301:1: warning: 'rseq_syscall' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_static_all':
/kisskb/src/lib/test_stackinit.c:257:1: warning: 'leaf_big_hole_static_all' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_static_all':
/kisskb/src/lib/test_stackinit.c:257:1: warning: 'test_big_hole_static_all' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_dynamic_all':
/kisskb/src/lib/test_stackinit.c:260:1: warning: 'leaf_big_hole_dynamic_all' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_dynamic_all':
/kisskb/src/lib/test_stackinit.c:260:1: warning: 'test_big_hole_dynamic_all' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_zero.isra.9':
/kisskb/src/lib/test_stackinit.c:254:1: warning: 'leaf_big_hole_zero.isra.9' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_zero':
/kisskb/src/lib/test_stackinit.c:254:1: warning: 'test_big_hole_zero' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_static_partial.isra.17':
/kisskb/src/lib/test_stackinit.c:256:1: warning: 'leaf_big_hole_static_partial.isra.17' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_static_partial':
/kisskb/src/lib/test_stackinit.c:256:1: warning: 'test_big_hole_static_partial' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_dynamic_partial.isra.29':
/kisskb/src/lib/test_stackinit.c:259:1: warning: 'leaf_big_hole_dynamic_partial.isra.29' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_dynamic_partial':
/kisskb/src/lib/test_stackinit.c:259:1: warning: 'test_big_hole_dynamic_partial' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_runtime_partial.isra.41':
/kisskb/src/lib/test_stackinit.c:262:1: warning: 'leaf_big_hole_runtime_partial.isra.41' uses dynamic stack allocation [enabled by default]
/kisskb/src/sound/soc/codecs/arizona.c: In function 'arizona_hw_params':
/kisskb/src/sound/soc/codecs/arizona.c:1893:3: warning: 'aif_rx_state' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/sound/soc/codecs/arizona.c:1890:3: warning: 'aif_tx_state' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_runtime_partial':
/kisskb/src/lib/test_stackinit.c:262:1: warning: 'test_big_hole_runtime_partial' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_runtime_all.isra.49':
/kisskb/src/lib/test_stackinit.c:263:1: warning: 'leaf_big_hole_runtime_all.isra.49' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_runtime_all':
/kisskb/src/lib/test_stackinit.c:263:1: warning: 'test_big_hole_runtime_all' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'leaf_big_hole_none.isra.63':
/kisskb/src/lib/test_stackinit.c:266:1: warning: 'leaf_big_hole_none.isra.63' uses dynamic stack allocation [enabled by default]
/kisskb/src/lib/test_stackinit.c: In function 'test_big_hole_none':
/kisskb/src/lib/test_stackinit.c:266:1: warning: 'test_big_hole_none' uses dynamic stack allocation [enabled by default]
/kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc':
/kisskb/src/fs/nfsd/nfs4xdr.c:2076:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/nfsd/nfs4xdr.c:2081:42: warning: 'end' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/devlink.c: In function 'devlink_fmsg_prepare_skb':
/kisskb/src/net/core/devlink.c:4304:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/nfs/super.c: In function 'nfs_show_stats':
/kisskb/src/fs/nfs/super.c:890:1: warning: 'nfs_show_stats' uses dynamic stack allocation [enabled by default]
/kisskb/src/sound/soc/codecs/da7219-aad.c: In function 'da7219_aad_hptest_work':
/kisskb/src/sound/soc/codecs/da7219-aad.c:321:17: warning: 'pll_ctrl' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/ncsi/ncsi-manage.c: In function 'set_one_vid':
/kisskb/src/net/ncsi/ncsi-manage.c:676:19: warning: 'vid' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c: In function 'proc_reg_open':
/kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c:337:21: note: 'pdeo' was declared here
/kisskb/src/fs/ocfs2/alloc.c: In function 'ocfs2_trim_mainbm':
/kisskb/src/fs/ocfs2/alloc.c:7604:17: warning: 'first_bit' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c: In function 'amdgpu_set_pp_od_clk_voltage':
/kisskb/src/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c:593:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/input/joystick/analog.c:172:2: warning: #warning Precise timer not defined for this architecture. [-Wcpp]
/kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery':
/kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr_rx':
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/sound/soc/codecs/rt5665.c: In function 'rt5665_i2s_pin_event':
/kisskb/src/sound/soc/codecs/rt5665.c:2666:33: warning: 'val2' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/sound/soc/codecs/rt5665.c:2663:33: warning: 'val1' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/iommu/io-pgtable-arm-v7s.c: In function '__arm_v7s_map.constprop.7':
/kisskb/src/drivers/iommu/io-pgtable-arm-v7s.c:449:7: warning: 'cptep' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/iio/imu/bmi160/bmi160_core.c: In function 'bmi160_config_pin.constprop.9':
/kisskb/src/drivers/iio/imu/bmi160/bmi160_core.c:618:3: warning: 'pin_name' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/iio/imu/bmi160/bmi160_core.c:606:29: warning: 'int_map_mask' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/iio/imu/bmi160/bmi160_core.c:599:29: warning: 'int_latch_mask' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/iio/imu/bmi160/bmi160_core.c:577:47: warning: 'int_out_ctrl_shift' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/sunrpc/stats.c: In function 'rpc_clnt_show_stats':
/kisskb/src/net/sunrpc/stats.c:268:1: warning: 'rpc_clnt_show_stats' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c: In function 'dm_determine_update_type_for_commit':
/kisskb/src/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:5860:10: warning: missing braces around initializer [-Wmissing-braces]
/kisskb/src/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:5860:10: warning: (near initialization for 'stream_update.src') [-Wmissing-braces]
/kisskb/src/drivers/soc/qcom/rpmh.c: In function 'rpmh_write_batch':
/kisskb/src/drivers/soc/qcom/rpmh.c:355:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/target/iscsi/cxgbit/cxgbit_target.c: In function 'cxgbit_tx_datain_iso.isra.32':
/kisskb/src/drivers/target/iscsi/cxgbit/cxgbit_target.c:501:1: warning: 'cxgbit_tx_datain_iso.isra.32' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/target/iscsi/iscsi_target.c: In function 'iscsit_send_datain':
/kisskb/src/drivers/target/iscsi/iscsi_target.c:2841:1: warning: 'iscsit_send_datain' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c: In function 'hclgevf_bind_ring_to_vector':
/kisskb/src/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c:1000:16: warning: 'type' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/wan/lmc/lmc_main.c: In function 'lmc_softreset':
/kisskb/src/drivers/net/wan/lmc/lmc_main.c:1851:9: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct tulip_desc_t *'
/kisskb/src/drivers/net/wan/lmc/lmc_main.c:1860:9: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct tulip_desc_t *'
/kisskb/src/drivers/net/wan/lmc/lmc_main.c:1862:5: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct tulip_desc_t *'
/kisskb/src/drivers/net/wan/lmc/lmc_main.c:1873:9: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct tulip_desc_t *'
/kisskb/src/drivers/net/wan/lmc/lmc_main.c:1875:5: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct tulip_desc_t *'
/kisskb/src/drivers/net/wan/lmc/lmc_main.c:1876:5: warning: passing argument 1 of 'virt_to_bus' discards 'volatile' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/io.h:1074:29: note: expected 'void *' but argument is of type 'volatile struct tulip_desc_t *'
/kisskb/src/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c: In function 'mvpp2_setup_bm_pool':
/kisskb/src/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:551:41: warning: overflow in implicit constant conversion [-Woverflow]
/kisskb/src/drivers/net/veth.c: In function 'veth_get_stats64':
/kisskb/src/drivers/net/veth.c:365:1: warning: 'veth_get_stats64' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/net/tun.c: In function 'tun_get_user':
/kisskb/src/drivers/net/tun.c:1842:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1755:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c: In function 'rvu_mbox_handler_npc_mcam_shift_entry':
/kisskb/src/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c:1815:15: warning: 'rc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/media/usb/dvb-usb/pctv452e.c: In function 'pctv452e_frontend_attach':
/kisskb/src/drivers/media/usb/dvb-usb/pctv452e.c:922:2: warning: value computed is not used [-Wunused-value]
/kisskb/src/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c: In function 'update_root_ft_create':
/kisskb/src/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c:845:5: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/ethernet/neterion/vxge/vxge-config.c: In function 'vxge_hw_device_hw_info_get':
/kisskb/src/drivers/net/ethernet/neterion/vxge/vxge-config.c:1089:1: warning: 'vxge_hw_device_hw_info_get' uses dynamic stack allocation [enabled by default]
/kisskb/src/drivers/gpu/drm/nouveau/nvkm/subdev/top/gk104.c: In function 'gk104_top_oneinit':
/kisskb/src/drivers/gpu/drm/nouveau/nvkm/subdev/top/gk104.c:104:1: warning: 'inst' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/gpu/drm/nouveau/nvkm/subdev/top/gk104.c:104:1: warning: 'type' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/arch/s390/boot/mem_detect.c: In function 'detect_memory':
/kisskb/src/arch/s390/boot/mem_detect.c:182:1: warning: 'detect_memory' uses dynamic stack allocation [enabled by default]
Completed OK
# rm -rf /kisskb/build/linus_s390-allyesconfig_s390x
# Build took: 0:11:19.190859