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authorH.J. Lu <hjl.tools@gmail.com>2024-02-26 06:37:03 -0800
committerH.J. Lu <hjl.tools@gmail.com>2024-02-28 09:02:56 -0800
commit0aac205a814a8511e98d02b91a8dc908f1c53cde (patch)
treee9ad8dfa06abd2f6d9b521bb95e9b7cfaa0d7de7 /sysdeps/x86/Makefile
parente6350be7e9cae8f71c96c1f06eab61b9acb227c8 (diff)
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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>
Diffstat (limited to 'sysdeps/x86/Makefile')
-rw-r--r--sysdeps/x86/Makefile7
1 files changed, 6 insertions, 1 deletions
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)