tree dfb5247eb84eac9a5d13cb671025c12b49429227
parent e219a4179fa58d4b553910ca26ed85b7d2f59461
author Elliott Hughes <enh@google.com> 1692651014 +0000
committer Elliott Hughes <enh@google.com> 1692651014 +0000

riscv64: increase jmp_buf size.

Today's risc-v psABI meeting brought up the topic of CFI-related ABI
changes, and FreeBSD wasn't worried about jmp_buf because they already
had twice the space we do (OpenBSD matches us, presumably because they
too just picked "the next power of two" over what they actually
required), and glibc wasn't worried because they have a hilariously
large sigset_t that they can steal space from (and apparently already
did to support the x86-64 CET shadow stack).

So rather than continue to assume that our minimal amount of free space
will suffice, let's just double it while our ABI isn't yet fixed, and
know we won't have to worry about it in a couple of years time when we
actually have riscv64 hardware shadow stack.

Test: treehugger
Change-Id: I2d4cb2f5db2ac8085a2c9e9ad4f910d0d4792005