musl/arch
Rich Felker d5a5045382 fix MINSIGSTKSZ values for archs with large signal contexts
the previous values (2k min and 8k default) were too small for some
archs. aarch64 reserves 4k in the signal context for future extensions
and requires about 4.5k total, and powerpc reportedly uses over 2k.
the new minimums are chosen to fit the saved context and also allow a
minimal signal handler to run.

since the default (SIGSTKSZ) has always been 6k larger than the
minimum, it is also increased to maintain the 6k usable by the signal
handler. this happens to be able to store one pathname buffer and
should be sufficient for calling any function in libc that doesn't
involve conversion between floating point and decimal representations.

x86 (both 32-bit and 64-bit variants) may also need a larger minimum
(around 2.5k) in the future to support avx-512, but the values on
these archs are left alone for now pending further analysis.

the value for PTHREAD_STACK_MIN is not increased to match MINSIGSTKSZ
at this time. this is so as not to preclude applications from using
extremely small thread stacks when they know they will not be handling
signals. unfortunately cancellation and multi-threaded set*id() use
signals as an implementation detail and therefore require a stack
large enough for a signal context, so applications which use extremely
small thread stacks may still need to avoid using these features.
2015-03-18 00:31:37 -04:00
..
aarch64 fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
arm fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
i386 fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
microblaze fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
mips fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
or1k fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
powerpc fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
sh fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
x32 fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00
x86_64 fix MINSIGSTKSZ values for archs with large signal contexts 2015-03-18 00:31:37 -04:00