# git rev-parse -q --verify a9dce6679d736cb3d612af39bab9f31f8db66f9b^{commit}
a9dce6679d736cb3d612af39bab9f31f8db66f9b
already have revision, skipping fetch
# git checkout -q -f -B kisskb a9dce6679d736cb3d612af39bab9f31f8db66f9b
# git clean -qxdf
# < git log -1
# commit a9dce6679d736cb3d612af39bab9f31f8db66f9b
# Merge: f67e3fb48912 575a0ae9744d
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Sat Mar 16 13:47:14 2019 -0700
# 
#     Merge tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
#     
#     Pull pidfd system call from Christian Brauner:
#      "This introduces the ability to use file descriptors from /proc/<pid>/
#       as stable handles on struct pid. Even if a pid is recycled the handle
#       will not change. For a start these fds can be used to send signals to
#       the processes they refer to.
#     
#       With the ability to use /proc/<pid> fds as stable handles on struct
#       pid we can fix a long-standing issue where after a process has exited
#       its pid can be reused by another process. If a caller sends a signal
#       to a reused pid it will end up signaling the wrong process.
#     
#       With this patchset we enable a variety of use cases. One obvious
#       example is that we can now safely delegate an important part of
#       process management - sending signals - to processes other than the
#       parent of a given process by sending file descriptors around via scm
#       rights and not fearing that the given process will have been recycled
#       in the meantime. It also allows for easy testing whether a given
#       process is still alive or not by sending signal 0 to a pidfd which is
#       quite handy.
#     
#       There has been some interest in this feature e.g. from systems
#       management (systemd, glibc) and container managers. I have requested
#       and gotten comments from glibc to make sure that this syscall is
#       suitable for their needs as well. In the future I expect it to take on
#       most other pid-based signal syscalls. But such features are left for
#       the future once they are needed.
#     
#       This has been sitting in linux-next for quite a while and has not
#       caused any issues. It comes with selftests which verify basic
#       functionality and also test that a recycled pid cannot be signaled via
#       a pidfd.
#     
#       Jon has written about a prior version of this patchset. It should
#       cover the basic functionality since not a lot has changed since then:
#     
#           https://lwn.net/Articles/773459/
#     
#       The commit message for the syscall itself is extensively documenting
#       the syscall, including it's functionality and extensibility"
#     
#     * tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
#       selftests: add tests for pidfd_send_signal()
#       signal: add pidfd_send_signal() syscall
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version
# < git log --format=%s --max-count=1 a9dce6679d736cb3d612af39bab9f31f8db66f9b
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_ppc64e_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  ppc64e_defconfig
# make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_ppc64e_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-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/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/kernel/trace/trace_dynevent.c: In function 'create_dyn_event':
/kisskb/src/kernel/trace/trace_dynevent.c:89:5: warning: 'ret' 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/net/bridge/br_netlink.c: In function 'br_afspec.isra.28':
/kisskb/src/net/bridge/br_netlink.c:652:7: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char':
/kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized]
/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/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq':
/kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here
/kisskb/src/net/netfilter/nf_nat_masquerade.c:15:21: warning: 'masq_refcnt6' defined but not used [-Wunused-variable]
/kisskb/src/net/sunrpc/xprtsock.c: In function 'xs_read_stream.constprop.18':
/kisskb/src/net/sunrpc/xprtsock.c:529:2: warning: 'read' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/sunrpc/xprtsock.c:498:15: note: 'read' was declared here
/kisskb/src/net/sunrpc/xprtsock.c:529:2: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/sunrpc/xprtsock.c:499:10: note: 'ret' was declared here
/kisskb/src/drivers/net/tun.c: In function 'tun_get_user':
/kisskb/src/drivers/net/tun.c:1845:30: 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]
WARNING: vmlinux.o (.PPC.EMB.apuinfo): unexpected non-allocatable section.
Did you forget to use "ax"/"aw" in a .S file?
Note that for example <linux/init.h> contains
section definitions for use in .S files.

INFO: Uncompressed kernel (size 0xc5eba8) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0xd00000)
Image Name:   Linux-5.0.0-ga9dce6679d73
Created:      Sun Mar 17 09:31:35 2019
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    5281540 Bytes = 5157.75 KiB = 5.04 MiB
Load Address: 00000000
Entry Point:  00000000
Completed OK
# rm -rf /kisskb/build/linus_ppc64e_defconfig_powerpc-gcc4.6
# Build took: 0:01:20.569813