musl/arch/sh
Szabolcs Nagy 610c5a8524 fix TLS layout of TLS variant I when there is a gap above TP
In TLS variant I the TLS is above TP (or above a fixed offset from TP)
but on some targets there is a reserved gap above TP before TLS starts.

This matters for the local-exec tls access model when the offsets of
TLS variables from the TP are hard coded by the linker into the
executable, so the libc must compute these offsets the same way as the
linker.  The tls offset of the main module has to be

	alignup(GAP_ABOVE_TP, main_tls_align).

If there is no TLS in the main module then the gap can be ignored
since musl does not use it and the tls access models of shared
libraries are not affected.

The previous setup only worked if (tls_align & -GAP_ABOVE_TP) == 0
(i.e. TLS did not require large alignment) because the gap was
treated as a fixed offset from TP.  Now the TP points at the end
of the pthread struct (which is aligned) and there is a gap above
it (which may also need alignment).

The fix required changing TP_ADJ and __pthread_self on affected
targets (aarch64, arm and sh) and in the tlsdesc asm the offset to
access the dtv changed too.
2018-06-02 19:38:44 -04:00
..
bits reverse definition dependency between PAGESIZE and PAGE_SIZE 2018-03-10 17:47:14 -05:00
atomic_arch.h fix build failure for sh4a due to missing colon in asm statement 2017-08-11 21:06:57 -04:00
crt_arch.h generalize sh entry point asm not to assume call dests fit in 12 bits 2015-11-02 18:11:36 -05:00
ksigaction.h fix signal return for sh/fdpic 2015-09-23 18:33:49 +00:00
pthread_arch.h fix TLS layout of TLS variant I when there is a gap above TP 2018-06-02 19:38:44 -04:00
reloc.h fix TLS layout of TLS variant I when there is a gap above TP 2018-06-02 19:38:44 -04:00
syscall_arch.h fix pread/pwrite syscall calling convention on sh 2016-08-11 18:36:46 -04:00