ARM: Add pointer encryption support

System Internals / glibc - Will Newton [linaro.org] - 3 October 2013 05:35 UTC

Add support for pointer encryption in glibc internal structures in C and assembler code. Pointer encryption is a glibc security feature described here:

https://sourceware.org/glibc/wiki/PointerEncryption

The ARM implementation uses global variables instead of thread pointer relative accesses to get the value of the pointer encryption guard because accessing the thread pointer can be very expensive on older ARM cores.

ports/ChangeLog.arm:

2013-10-03 Will Newton

- sysdeps/arm/__longjmp.S (__longjmp): Demangle fp, sp and lr when restoring register values.
- sysdeps/arm/include/bits/setjmp.h (JMP_BUF_REGLIST): Remove sp and lr from list and replace fp with a4.
- sysdeps/arm/jmpbuf-unwind.h (_jmpbuf_sp): New function. (_JMPBUF_UNWINDS_ADJ): Call _jmpbuf_sp.
- sysdeps/arm/setjmp.S (__sigsetjmp): Mangle fp, sp and lr before storing register values.
- sysdeps/arm/sysdep.h (LDST_GLOBAL): New macro.
- sysdeps/unix/sysv/linux/arm/sysdep.h (PTR_MANGLE): New macro. (PTR_DEMANGLE): Likewise. (PTR_MANGLE2): Likewise. (PTR_DEMANGLE2): Likewise.

b7f2d27 ARM: Add pointer encryption support.
ports/ChangeLog.arm | 15 ++++++++++
ports/sysdeps/arm/__longjmp.S | 14 ++++++++++
ports/sysdeps/arm/include/bits/setjmp.h | 5 ++--
ports/sysdeps/arm/jmpbuf-unwind.h | 13 ++++++++-
ports/sysdeps/arm/setjmp.S | 14 ++++++++++
ports/sysdeps/arm/sysdep.h | 12 ++++++++
ports/sysdeps/unix/sysv/linux/arm/sysdep.h | 42 ++++++++++++++++++++++++++--
7 files changed, 109 insertions(+), 6 deletions(-)

Upstream: sourceware.org

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