From 0aac205a814a8511e98d02b91a8dc908f1c53cde Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Mon, 26 Feb 2024 06:37:03 -0800 Subject: 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 --- sysdeps/x86/Makefile | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'sysdeps/x86/Makefile') diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile index 73b29cc78c..5311b594af 100644 --- a/sysdeps/x86/Makefile +++ b/sysdeps/x86/Makefile @@ -1,5 +1,5 @@ ifeq ($(subdir),csu) -gen-as-const-headers += cpu-features-offsets.sym +gen-as-const-headers += cpu-features-offsets.sym features-offsets.sym endif ifeq ($(subdir),elf) @@ -86,6 +86,11 @@ endif tst-ifunc-isa-2-ENV = GLIBC_TUNABLES=glibc.cpu.hwcaps=-SSE4_2,-AVX,-AVX2,-AVX512F tst-ifunc-isa-2-static-ENV = $(tst-ifunc-isa-2-ENV) tst-hwcap-tunables-ARGS = -- $(host-test-program-cmd) + +CFLAGS-tst-gnu2-tls2.c += -msse +CFLAGS-tst-gnu2-tls2mod0.c += -msse2 -mtune=haswell +CFLAGS-tst-gnu2-tls2mod1.c += -msse2 -mtune=haswell +CFLAGS-tst-gnu2-tls2mod2.c += -msse2 -mtune=haswell endif ifeq ($(subdir),math) -- cgit 1.4.1