Commit Graph

2 Commits

Author SHA1 Message Date
H.J. Lu
9b7091415a x86-64: Update _dl_tlsdesc_dynamic to preserve AMX registers
_dl_tlsdesc_dynamic should also preserve AMX registers which are
caller-saved.  Add X86_XSTATE_TILECFG_ID and X86_XSTATE_TILEDATA_ID
to x86-64 TLSDESC_CALL_STATE_SAVE_MASK.  Compute the AMX state size
and save it in xsave_state_full_size which is only used by
_dl_tlsdesc_dynamic_xsave and _dl_tlsdesc_dynamic_xsavec.  This fixes
the AMX part of BZ #31372.  Tested on AMX processor.

AMX test is enabled only for compilers with the fix for

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114098

GCC 14 and GCC 11/12/13 branches have the bug fix.
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
2024-02-29 04:30:01 -08:00
H.J. Lu
0aac205a81 x86: Update _dl_tlsdesc_dynamic to preserve caller-saved registers
Compiler generates the following instruction sequence for GNU2 dynamic
TLS access:

	leaq	tls_var@TLSDESC(%rip), %rax
	call	*tls_var@TLSCALL(%rax)

or

	leal	tls_var@TLSDESC(%ebx), %eax
	call	*tls_var@TLSCALL(%eax)

CALL instruction is transparent to compiler which assumes all registers,
except for EFLAGS and RAX/EAX, are unchanged after CALL.  When
_dl_tlsdesc_dynamic is called, it calls __tls_get_addr on the slow
path.  __tls_get_addr is a normal function which doesn't preserve any
caller-saved registers.  _dl_tlsdesc_dynamic saved and restored integer
caller-saved registers, but didn't preserve any other caller-saved
registers.  Add _dl_tlsdesc_dynamic IFUNC functions for FNSAVE, FXSAVE,
XSAVE and XSAVEC to save and restore all caller-saved registers.  This
fixes BZ #31372.

Add GLRO(dl_x86_64_runtime_resolve) with GLRO(dl_x86_tlsdesc_dynamic)
to optimize elf_machine_runtime_setup.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-02-28 09:02:56 -08:00