glibc/sysdeps/loongarch
H.J. Lu 1ea16a207c i386: Update ___tls_get_addr to preserve vector registers
Compiler generates the following instruction sequence for dynamic TLS
access:

	leal	tls_var@tlsgd(,%ebx,1), %eax
	call	___tls_get_addr@PLT

CALL instruction is transparent to compiler which assumes all registers,
except for EFLAGS, AX, CX, and DX, are unchanged after CALL.  But
___tls_get_addr is a normal function which doesn't preserve any vector
registers.

1. Rename the generic __tls_get_addr function to ___tls_get_addr_internal.
2. Change ___tls_get_addr to a wrapper function with implementations for
FNSAVE, FXSAVE, XSAVE and XSAVEC to save and restore all vector registers.
3. dl-tlsdesc-dynamic.h has:

_dl_tlsdesc_dynamic:
	/* Like all TLS resolvers, preserve call-clobbered registers.
	   We need two scratch regs anyway.  */
	subl	$32, %esp
	cfi_adjust_cfa_offset (32)

It is wrong to use

	movl	%ebx, -28(%esp)
	movl	%esp, %ebx
	cfi_def_cfa_register(%ebx)
	...
	mov	%ebx, %esp
	cfi_def_cfa_register(%esp)
	movl	-28(%esp), %ebx

to preserve EBX on stack.  Fix it with:

	movl	%ebx, 28(%esp)
	movl	%esp, %ebx
	cfi_def_cfa_register(%ebx)
	...
	mov	%ebx, %esp
	cfi_def_cfa_register(%esp)
	movl	28(%esp), %ebx

4. Update _dl_tlsdesc_dynamic to call ___tls_get_addr_internal directly.
5. Add have-test-mtls-traditional to compile tst-tls23-mod.c with
traditional TLS variant to verify the fix.
6. Define DL_RUNTIME_RESOLVE_REALIGN_STACK in sysdeps/x86/sysdep.h.

This fixes BZ #32996.

Co-Authored-By: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit 848f0e46f0)
2025-08-20 11:09:07 -07:00
..
bits
fpu LoongArch: Correct {__ieee754, _}_scalb -> {__ieee754, _}_scalbf 2024-03-22 09:25:39 +08:00
lp64
nofpu
nptl
sys LoongArch: Add vector implementation for _dl_runtime_resolve. 2023-07-11 10:56:01 +08:00
Implies
Makefile
__longjmp.S
abort-instr.h
bsd-_setjmp.c
bsd-setjmp.c
configure configure: Use autoconf 2.71 2023-07-17 10:08:10 -04:00
configure.ac
dl-irel.h
dl-link.sym
dl-machine.h LoongArch: Fix soft-float bug about _dl_runtime_resolve{,lsx,lasx} 2023-07-11 11:57:12 +08:00
dl-tls.h
dl-trampoline.S LoongArch: Fix soft-float bug about _dl_runtime_resolve{,lsx,lasx} 2023-07-11 11:57:12 +08:00
dl-trampoline.h LoongArch: Delete excessively allocated memory. 2023-12-10 15:09:59 +08:00
e_sqrtl.c
fpu_control.h
hp-timing.h
jmpbuf-offsets.h
jmpbuf-unwind.h
ldsodefs.h LoongArch: Add vector implementation for _dl_runtime_resolve. 2023-07-11 10:56:01 +08:00
libc-tls.c
linkmap.h
machine-gmon.h
math_private.h
preconfigure i386: Update ___tls_get_addr to preserve vector registers 2025-08-20 11:09:07 -07:00
preconfigure.ac i386: Update ___tls_get_addr to preserve vector registers 2025-08-20 11:09:07 -07:00
setjmp.S
sfp-machine.h
sotruss-lib.c
stackinfo.h
start.S
tininess.h
tst-audit.h