glibc/sysdeps/powerpc
H.J. Lu 848f0e46f0 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>
2025-06-19 04:30:31 +08:00
..
bits
fpu math: Refactor how to use libm-test-ulps 2025-03-12 13:40:07 -03:00
nofpu math: Refactor how to use libm-test-ulps 2025-03-12 13:40:07 -03:00
nptl
power4
power6
powerpc32 powerpc: Remove POWER7 strncasecmp optimization 2025-05-06 13:31:01 -03:00
powerpc64 powerpc: Remove assembler workarounds 2025-06-18 09:29:10 +02:00
sys/platform
Makefile i386: Update ___tls_get_addr to preserve vector registers 2025-06-19 04:30:31 +08:00
Versions
abort-instr.h
atomic-machine.h
dl-diagnostics-cpu.c
dl-lookupcfg.h
dl-procinfo.c
dl-tls.c
dl-tls.h
dl-tunables.list
elf-initfini.h
fpu_control.h
gccframe.h
hwcapinfo.c
hwcapinfo.h
ifunc-sel.h
jmpbuf-offsets.h
jmpbuf-unwind.h
ldsodefs.h
libc-tls.c
locale-defines.sym
longjmp.c
machine-gmon.h
math-tests-snan-cast.h
math-use-builtins-ffs.h
mod-cache-ppc.c
mod-tlsopt-powerpc.c
mp_clz_tab.c
novmx-longjmp.c
novmx-sigjmp.c
novmxsetjmp.h
preconfigure
preconfigure.ac
rtld-global-offsets.sym
sigjmp.c
sotruss-lib.c
string-fza.h
sysdep.h
test-arith.c
test-arithf.c
test-get_hwcap-static.c
test-get_hwcap.c
test-gettimebase.c
thread_pointer.h
tst-cache-ppc-static-dlopen.c
tst-cache-ppc-static.c
tst-cache-ppc.c
tst-set_ppr.c
tst-stack-align.h
tst-tlsifunc-static.c
tst-tlsifunc.c
tst-tlsopt-powerpc.c
utmp-size.h