linux/include/uapi/asm-generic
Peter Collingbourne a54f0dfda7 signal: define the SA_UNSUPPORTED bit in sa_flags
Define a sa_flags bit, SA_UNSUPPORTED, which will never be supported
in the uapi. The purpose of this flag bit is to allow userspace to
distinguish an old kernel that does not clear unknown sa_flags bits
from a kernel that supports every flag bit.

In other words, if userspace does something like:

  act.sa_flags |= SA_UNSUPPORTED;
  sigaction(SIGSEGV, &act, 0);
  sigaction(SIGSEGV, 0, &oldact);

and finds that SA_UNSUPPORTED remains set in oldact.sa_flags, it means
that the kernel cannot be trusted to have cleared unknown flag bits
from sa_flags, so no assumptions about flag bit support can be made.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://linux-review.googlesource.com/id/Ic2501ad150a3a79c1cf27fb8c99be342e9dffbcb
Link: https://lkml.kernel.org/r/bda7ddff8895a9bc4ffc5f3cf3d4d37a32118077.1605582887.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-11-23 10:31:06 -06:00
..
auxvec.h
bitsperlong.h
bpf_perf_event.h bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type 2017-12-05 15:02:40 +01:00
errno-base.h
errno.h
fcntl.h
hugetlb_encode.h powerpc/8xx: Support 16k hugepages with 4k pages 2020-09-15 22:13:31 +10:00
int-l64.h
int-ll64.h
ioctl.h
ioctls.h tty/serial_core: add ISO7816 infrastructure 2018-10-02 13:38:55 -07:00
ipcbuf.h arch: ipcbuf.h: make uapi asm/ipcbuf.h self-contained 2019-12-04 19:44:14 -08:00
Kbuild kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
kvm_para.h
mman-common.h mm: Reserve asm-generic prot flags 0x10 and 0x20 for arch use 2020-01-17 12:48:36 +00:00
mman.h mm/mmap: move common defines to mman-common.h 2019-07-16 19:23:25 -07:00
msgbuf.h arch: msgbuf.h: make uapi asm/msgbuf.h self-contained 2019-12-04 19:44:14 -08:00
param.h
poll.h unify {de,}mangle_poll(), get rid of kernel-side POLL... 2018-02-11 14:37:22 -08:00
posix_types.h y2038: hide timeval/timespec/itimerval/itimerspec types 2020-02-21 11:22:15 -08:00
resource.h
sembuf.h arch: sembuf.h: make uapi asm/sembuf.h self-contained 2019-12-04 19:44:14 -08:00
setup.h
shmbuf.h y2038: ipc: remove __kernel_time_t reference from headers 2019-11-15 14:38:28 +01:00
siginfo.h arm64: mte: Add specific SIGSEGV codes 2020-09-04 12:46:06 +01:00
signal-defs.h signal: define the SA_UNSUPPORTED bit in sa_flags 2020-11-23 10:31:06 -06:00
signal.h arch: move SA_* definitions to generic headers 2020-11-23 10:31:05 -06:00
socket.h bpf: net: Add SO_DETACH_REUSEPORT_BPF 2019-06-15 01:21:19 +02:00
sockios.h net: socket: implement 64-bit timestamps 2019-04-19 14:07:40 -07:00
stat.h
statfs.h
swab.h
termbits.h
termios.h
types.h
ucontext.h
unistd.h mm/madvise: introduce process_madvise() syscall: an external memory hinting API 2020-10-18 09:27:10 -07:00