# 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/korg/gcc-8.1.0-nolibc/nds32le-linux/bin/nds32le-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/nds32le-linux/bin/nds32le-linux-ld --version
# < git log --format=%s --max-count=1 a9dce6679d736cb3d612af39bab9f31f8db66f9b
# < make -s -j 120 ARCH=nds32 O=/kisskb/build/linus_nds32-allyesconfig_nds32le CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/nds32le-linux/bin/nds32le-linux-  allyesconfig
# make -s -j 120 ARCH=nds32 O=/kisskb/build/linus_nds32-allyesconfig_nds32le CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/nds32le-linux/bin/nds32le-linux-  
/kisskb/src/mm/mprotect.c: In function 'change_pte_range':
/kisskb/src/mm/mprotect.c:42:20: warning: unused variable 'mm' [-Wunused-variable]
  struct mm_struct *mm = vma->vm_mm;
                    ^~
In file included from /kisskb/src/include/linux/printk.h:7,
                 from /kisskb/src/include/linux/kernel.h:15,
                 from /kisskb/src/include/linux/fs_context.h:15,
                 from /kisskb/src/fs/fs_parser.c:13:
/kisskb/src/fs/fs_parser.c: In function 'fs_validate_description':
/kisskb/src/include/linux/kern_levels.h:5:18: warning: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'int' [-Wformat=]
 #define KERN_SOH "\001"  /* ASCII Start Of Header */
                  ^~~~~~
/kisskb/src/include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH'
 #define KERN_ERR KERN_SOH "3" /* error conditions */
                  ^~~~~~~~
/kisskb/src/include/linux/printk.h:302:9: note: in expansion of macro 'KERN_ERR'
  printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
         ^~~~~~~~
/kisskb/src/fs/fs_parser.c:413:6: note: in expansion of macro 'pr_err'
      pr_err("VALIDATE %s: e[%lu] enum val for %s\n",
      ^~~~~~
/kisskb/src/fs/fs_parser.c:413:31: note: format string is defined here
      pr_err("VALIDATE %s: e[%lu] enum val for %s\n",
                             ~~^
                             %u
/kisskb/src/drivers/input/joystick/analog.c:172:2: warning: #warning Precise timer not defined for this architecture. [-Wcpp]
 #warning Precise timer not defined for this architecture.
  ^~~~~~~
/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 [-Wmaybe-uninitialized]
  if (ret == -EOPNOTSUPP)
     ^
WARNING: EXPORT symbol "copy_page" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "clear_page" [vmlinux] version generation failed, symbol will not be versioned.
Completed OK
# rm -rf /kisskb/build/linus_nds32-allyesconfig_nds32le
# Build took: 0:06:02.416776