Add support for saving and restoring f0-f15 across signal delivery.
The target_xtensa_xtregs_fp struct carries 32-bit f-regs for cores
with XTENSA_OPTION_FP_COPROCESSOR; target_xtensa_xtregs_dfp carries
64-bit f-regs for cores with XTENSA_OPTION_DFP_COPROCESSOR.
Lock the xtregs region via lock_user before reading on sigreturn,
since sc_xtregs is a user-space pointer that may lie outside the
locked sigframe.
Signed-off-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>
6858e3a71c