This patch consolidates the read Linux syscall implementation on
sysdeps/unix/sysv/linux/read.c. This leads to a different frame
pointer creation on some architectures:
* It fixes BZ#21428 on aarch64, since now the returned address
for the read syscall can be correctly found out by
backtrace_symbols.
* It makes tst-backtrace{5,6} fails on powerpc due an issue on
its custom backtrace implementation. It is fixed on subsequent
patch from this set.
Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
arch64-linux-gnu, arm-linux-gnueabihf, and powerpc64le-linux-gnu.
[BZ #21428]
* include/unistd.h (read): Add hidden proto.
* io/Makefile (CFLAGS-read.c): New rule.
* nptl/Makefile (CFLAGS-read.c): New rule.
* sysdeps/unix/sysv/linux/read.c: New file.
f6a191a6ee