forked from Minki/linux
a54f0dfda7
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> |
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| asm-generic | ||
| drm | ||
| linux | ||
| misc | ||
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| Kbuild | ||