aarch64: add NEWS entry about branch protection support

This is a new security feature that relies on architecture
extensions and needs glibc to be built with a gcc configured
with branch protection.
This commit is contained in:
Szabolcs Nagy 2020-06-11 18:19:40 +01:00
parent d174ec248d
commit a2a83bf6d9

11
NEWS
View File

@ -67,6 +67,17 @@ Major new features:
They should be used instead of sys_errlist and sys_nerr, both are
thread and async-signal safe. These functions are GNU extensions.
* AArch64 now supports standard branch protection security hardening
in glibc when it is built with a GCC that is configured with
--enable-standard-branch-protection. This includes branch target
identification (BTI) and pointer authentication for return addresses
(PAC-RET). They require armv8.5-a and armv8.3-a architecture
extensions respectively for the protection to be effective,
otherwise the used instructions are nops. User code can use PAC-RET
without libc support, but BTI requires a libc that is built with BTI
support, otherwise runtime objects linked into user code will not be
BTI compatible.
Deprecated and removed features, and other changes affecting compatibility:
* The deprecated <sys/sysctl.h> header and the sysctl function have been