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 --- elf/Makefile | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'elf/Makefile') diff --git a/elf/Makefile b/elf/Makefile index 36c04baf02..02dc476e27 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -424,6 +424,7 @@ tests += \ tst-glibc-hwcaps-prepend \ tst-global1 \ tst-global2 \ + tst-gnu2-tls2 \ tst-initfinilazyfail \ tst-initorder \ tst-initorder2 \ @@ -846,6 +847,9 @@ modules-names += \ tst-filterobj-flt \ tst-finilazyfailmod \ tst-globalmod2 \ + tst-gnu2-tls2mod0 \ + tst-gnu2-tls2mod1 \ + tst-gnu2-tls2mod2 \ tst-initlazyfailmod \ tst-initorder2a \ tst-initorder2b \ @@ -3044,8 +3048,22 @@ $(objpfx)tst-tlsgap.out: \ $(objpfx)tst-tlsgap-mod0.so \ $(objpfx)tst-tlsgap-mod1.so \ $(objpfx)tst-tlsgap-mod2.so + +$(objpfx)tst-gnu2-tls2: $(shared-thread-library) +$(objpfx)tst-gnu2-tls2.out: \ + $(objpfx)tst-gnu2-tls2mod0.so \ + $(objpfx)tst-gnu2-tls2mod1.so \ + $(objpfx)tst-gnu2-tls2mod2.so + ifeq (yes,$(have-mtls-dialect-gnu2)) +# This test fails if dl_tlsdesc_dynamic doesn't preserve all caller-saved +# registers. See https://sourceware.org/bugzilla/show_bug.cgi?id=31372 +test-xfail-tst-gnu2-tls2 = yes + CFLAGS-tst-tlsgap-mod0.c += -mtls-dialect=gnu2 CFLAGS-tst-tlsgap-mod1.c += -mtls-dialect=gnu2 CFLAGS-tst-tlsgap-mod2.c += -mtls-dialect=gnu2 +CFLAGS-tst-gnu2-tls2mod0.c += -mtls-dialect=gnu2 +CFLAGS-tst-gnu2-tls2mod1.c += -mtls-dialect=gnu2 +CFLAGS-tst-gnu2-tls2mod2.c += -mtls-dialect=gnu2 endif -- cgit 1.4.1