commit a8ba52bde58c69f2b31da62ad2311f119adf6cb9 Author: Adhemerval Zanella Date: Tue Mar 12 13:21:19 2024 -0300 arm: Update _dl_tlsdesc_dynamic to preserve caller-saved registers (BZ 31372) ARM _dl_tlsdesc_dynamic slow path has two issues: * The ip/r12 is defined by AAPCS as a scratch register, and gcc is used to save the stack pointer before on some function calls. So it should also be saved/restored as well. It fixes the tst-gnu2-tls2. * None of the possible VFP registers are saved/restored. ARM has the additional complexity to have different VFP bank sizes (depending of VFP support by the chip). The tst-gnu2-tls2 test is extended to check for VFP registers, although only for hardfp builds. Different than setcontext, _dl_tlsdesc_dynamic does not have HWCAP_ARM_IWMMXT (I don't have a way to properly test it and it is almost a decade since newer hardware was released). With this patch there is no need to mark tst-gnu2-tls2 as XFAIL. Checked on arm-linux-gnueabihf. Reviewed-by: H.J. Lu (cherry picked from commit 64c7e344289ed085517c2227d8e3b06388242c13) diff --git a/config.h.in b/config.h.in index 44a34072a47aa008..4d33c63a841d3d6d 100644 --- a/config.h.in +++ b/config.h.in @@ -141,6 +141,9 @@ /* LOONGARCH floating-point ABI for ld.so. */ #undef LOONGARCH_ABI_FRLEN +/* Define whether ARM used hard-float and support VFPvX-D32. */ +#undef HAVE_ARM_PCS_VFP_D32 + /* Linux specific: minimum supported kernel version. */ #undef __LINUX_KERNEL_VERSION diff --git a/elf/Makefile b/elf/Makefile index c5c37a9147e69d83..030db4d207d3491e 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -3056,10 +3056,6 @@ $(objpfx)tst-gnu2-tls2.out: \ $(objpfx)tst-gnu2-tls2mod2.so ifeq (yes,$(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 diff --git a/elf/tst-gnu2-tls2.h b/elf/tst-gnu2-tls2.h index 77964a57a352e6a4..1ade8151e200af68 100644 --- a/elf/tst-gnu2-tls2.h +++ b/elf/tst-gnu2-tls2.h @@ -27,6 +27,10 @@ extern struct tls *apply_tls (struct tls *); /* An architecture can define them to verify that clobber caller-saved registers aren't changed by the implicit TLSDESC call. */ +#ifndef INIT_TLSDESC_CALL +# define INIT_TLSDESC_CALL() +#endif + #ifndef BEFORE_TLSDESC_CALL # define BEFORE_TLSDESC_CALL() #endif diff --git a/elf/tst-gnu2-tls2mod0.c b/elf/tst-gnu2-tls2mod0.c index 45556a0e173922cc..3fe3c142777abe04 100644 --- a/elf/tst-gnu2-tls2mod0.c +++ b/elf/tst-gnu2-tls2mod0.c @@ -16,13 +16,14 @@ License along with the GNU C Library; if not, see . */ -#include "tst-gnu2-tls2.h" +#include __thread struct tls tls_var0 __attribute__ ((visibility ("hidden"))); struct tls * apply_tls (struct tls *p) { + INIT_TLSDESC_CALL (); BEFORE_TLSDESC_CALL (); tls_var0 = *p; struct tls *ret = &tls_var0; diff --git a/elf/tst-gnu2-tls2mod1.c b/elf/tst-gnu2-tls2mod1.c index e10b9dbc0a7573c7..e2105384689e2d2e 100644 --- a/elf/tst-gnu2-tls2mod1.c +++ b/elf/tst-gnu2-tls2mod1.c @@ -16,13 +16,14 @@ License along with the GNU C Library; if not, see . */ -#include "tst-gnu2-tls2.h" +#include __thread struct tls tls_var1[100] __attribute__ ((visibility ("hidden"))); struct tls * apply_tls (struct tls *p) { + INIT_TLSDESC_CALL (); BEFORE_TLSDESC_CALL (); tls_var1[1] = *p; struct tls *ret = &tls_var1[1]; diff --git a/elf/tst-gnu2-tls2mod2.c b/elf/tst-gnu2-tls2mod2.c index 141af51e55b8bf34..6d3031dc5fbc1041 100644 --- a/elf/tst-gnu2-tls2mod2.c +++ b/elf/tst-gnu2-tls2mod2.c @@ -16,13 +16,14 @@ License along with the GNU C Library; if not, see . */ -#include "tst-gnu2-tls2.h" +#include __thread struct tls tls_var2 __attribute__ ((visibility ("hidden"))); struct tls * apply_tls (struct tls *p) { + INIT_TLSDESC_CALL (); BEFORE_TLSDESC_CALL (); tls_var2 = *p; struct tls *ret = &tls_var2; diff --git a/sysdeps/arm/configure b/sysdeps/arm/configure index 35e2918922300956..4ef4d46cbd5384e9 100644 --- a/sysdeps/arm/configure +++ b/sysdeps/arm/configure @@ -187,6 +187,38 @@ else default-abi = soft" fi +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether VFP supports 32 registers" >&5 +printf %s "checking whether VFP supports 32 registers... " >&6; } +if test ${libc_cv_arm_pcs_vfp_d32+y} +then : + printf %s "(cached) " >&6 +else $as_nop + +cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + +void foo (void) +{ + asm volatile ("vldr d16,=17" : : : "d16"); +} + +_ACEOF +if ac_fn_c_try_compile "$LINENO" +then : + libc_cv_arm_pcs_vfp_d32=yes +else $as_nop + libc_cv_arm_pcs_vfp_d32=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext +fi +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_arm_pcs_vfp_d32" >&5 +printf "%s\n" "$libc_cv_arm_pcs_vfp_d32" >&6; } +if test "$libc_cv_arm_pcs_vfp_d32" = yes ; +then + printf "%s\n" "#define HAVE_ARM_PCS_VFP_D32 1" >>confdefs.h + +fi + { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether PC-relative relocs in movw/movt work properly" >&5 printf %s "checking whether PC-relative relocs in movw/movt work properly... " >&6; } if test ${libc_cv_arm_pcrel_movw+y} diff --git a/sysdeps/arm/configure.ac b/sysdeps/arm/configure.ac index 5172e30bbe79f995..cd00ddc9d9ade5d7 100644 --- a/sysdeps/arm/configure.ac +++ b/sysdeps/arm/configure.ac @@ -21,6 +21,21 @@ else LIBC_CONFIG_VAR([default-abi], [soft]) fi +AC_CACHE_CHECK([whether VFP supports 32 registers], + libc_cv_arm_pcs_vfp_d32, [ +AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +void foo (void) +{ + asm volatile ("vldr d16,=17" : : : "d16"); +} +]])], + [libc_cv_arm_pcs_vfp_d32=yes], + [libc_cv_arm_pcs_vfp_d32=no])]) +if test "$libc_cv_arm_pcs_vfp_d32" = yes ; +then + AC_DEFINE(HAVE_ARM_PCS_VFP_D32) +fi + AC_CACHE_CHECK([whether PC-relative relocs in movw/movt work properly], libc_cv_arm_pcrel_movw, [ cat > conftest.s <<\EOF diff --git a/sysdeps/arm/dl-tlsdesc.S b/sysdeps/arm/dl-tlsdesc.S index 764c56e70f046b03..ada106521da8971a 100644 --- a/sysdeps/arm/dl-tlsdesc.S +++ b/sysdeps/arm/dl-tlsdesc.S @@ -19,6 +19,7 @@ #include #include #include +#include #include "tlsdesc.h" .text @@ -83,14 +84,20 @@ _dl_tlsdesc_dynamic(struct tlsdesc *tdp) .align 2 _dl_tlsdesc_dynamic: /* Our calling convention is to clobber r0, r1 and the processor - flags. All others that are modified must be saved */ - eabi_save ({r2,r3,r4,lr}) - push {r2,r3,r4,lr} - cfi_adjust_cfa_offset (16) + flags. All others that are modified must be saved. r5 is + used as the hwcap value to avoid reload after __tls_get_addr + call. If required we will save the vector register on the slow + path. */ + eabi_save ({r2,r3,r4,r5,ip,lr}) + push {r2,r3,r4,r5,ip,lr} + cfi_adjust_cfa_offset (24) cfi_rel_offset (r2,0) cfi_rel_offset (r3,4) cfi_rel_offset (r4,8) - cfi_rel_offset (lr,12) + cfi_rel_offset (r5,12) + cfi_rel_offset (ip,16) + cfi_rel_offset (lr,20) + ldr r1, [r0] /* td */ GET_TLS (lr) mov r4, r0 /* r4 = tp */ @@ -113,22 +120,69 @@ _dl_tlsdesc_dynamic: rsbne r0, r4, r3 bne 2f 1: mov r0, r1 + + /* Load the hwcap to check for vector support. */ + ldr r2, 3f + ldr r1, .Lrtld_global_ro +0: add r2, pc, r2 + ldr r2, [r2, r1] + ldr r5, [r2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET] + +#ifdef __SOFTFP__ + tst r5, #HWCAP_ARM_VFP + beq .Lno_vfp +#endif + + /* Store the VFP registers. Don't use VFP instructions directly + because this code is used in non-VFP multilibs. */ +#define VFP_STACK_REQ (32*8 + 8) + sub sp, sp, VFP_STACK_REQ + cfi_adjust_cfa_offset (VFP_STACK_REQ) + mov r3, sp + .inst 0xeca30b20 /* vstmia r3!, {d0-d15} */ + tst r5, #HWCAP_ARM_VFPD32 + beq 4f + .inst 0xece30b20 /* vstmia r3!, {d16-d31} */ + /* Store the floating-point status register. */ +4: .inst 0xeef12a10 /* vmrs r2, fpscr */ + str r2, [r3] +.Lno_vfp: bl __tls_get_addr rsb r0, r4, r0 +#ifdef __SOFTFP__ + tst r5, #HWCAP_ARM_VFP + beq 2f +#endif + mov r3, sp + .inst 0xecb30b20 /* vldmia r3!, {d0-d15} */ + tst r5, #HWCAP_ARM_VFPD32 + beq 5f + .inst 0xecf30b20 /* vldmia r3!, {d16-d31} */ + ldr r4, [r3] +5: .inst 0xeee14a10 /* vmsr fpscr, r4 */ + add sp, sp, VFP_STACK_REQ + cfi_adjust_cfa_offset (-VFP_STACK_REQ) + 2: #if ((defined (__ARM_ARCH_4T__) && defined (__THUMB_INTERWORK__)) \ || defined (ARM_ALWAYS_BX)) - pop {r2,r3,r4, lr} - cfi_adjust_cfa_offset (-16) + pop {r2,r3,r4,r5,ip, lr} + cfi_adjust_cfa_offset (-20) cfi_restore (lr) + cfi_restore (ip) + cfi_restore (r5) cfi_restore (r4) cfi_restore (r3) cfi_restore (r2) bx lr #else - pop {r2,r3,r4, pc} + pop {r2,r3,r4,r5,ip, pc} #endif eabi_fnend cfi_endproc .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic + +3: .long _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS +.Lrtld_global_ro: + .long C_SYMBOL_NAME(_rtld_global_ro)(GOT) #endif /* SHARED */ diff --git a/sysdeps/arm/tst-gnu2-tls2.h b/sysdeps/arm/tst-gnu2-tls2.h new file mode 100644 index 0000000000000000..e413ac21fb9ed9bf --- /dev/null +++ b/sysdeps/arm/tst-gnu2-tls2.h @@ -0,0 +1,128 @@ +/* Test TLSDESC relocation. ARM version. + Copyright (C) 2024 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + +#ifndef __SOFTFP__ + +# ifdef HAVE_ARM_PCS_VFP_D32 +# define SAVE_VFP_D32 \ + asm volatile ("vldr d16,=17" : : : "d16"); \ + asm volatile ("vldr d17,=18" : : : "d17"); \ + asm volatile ("vldr d18,=19" : : : "d18"); \ + asm volatile ("vldr d19,=20" : : : "d19"); \ + asm volatile ("vldr d20,=21" : : : "d20"); \ + asm volatile ("vldr d21,=22" : : : "d21"); \ + asm volatile ("vldr d22,=23" : : : "d22"); \ + asm volatile ("vldr d23,=24" : : : "d23"); \ + asm volatile ("vldr d24,=25" : : : "d24"); \ + asm volatile ("vldr d25,=26" : : : "d25"); \ + asm volatile ("vldr d26,=27" : : : "d26"); \ + asm volatile ("vldr d27,=28" : : : "d27"); \ + asm volatile ("vldr d28,=29" : : : "d28"); \ + asm volatile ("vldr d29,=30" : : : "d29"); \ + asm volatile ("vldr d30,=31" : : : "d30"); \ + asm volatile ("vldr d31,=32" : : : "d31"); +# else +# define SAVE_VFP_D32 +# endif + +# define INIT_TLSDESC_CALL() \ + unsigned long hwcap = getauxval (AT_HWCAP) + +/* Set each vector register to a value from 1 to 32 before the TLS access, + dump to memory after TLS access, and compare with the expected values. */ + +# define BEFORE_TLSDESC_CALL() \ + if (hwcap & HWCAP_ARM_VFP) \ + { \ + asm volatile ("vldr d0,=1" : : : "d0"); \ + asm volatile ("vldr d1,=2" : : : "d1"); \ + asm volatile ("vldr d2,=3" : : : "d1"); \ + asm volatile ("vldr d3,=4" : : : "d3"); \ + asm volatile ("vldr d4,=5" : : : "d4"); \ + asm volatile ("vldr d5,=6" : : : "d5"); \ + asm volatile ("vldr d6,=7" : : : "d6"); \ + asm volatile ("vldr d7,=8" : : : "d7"); \ + asm volatile ("vldr d8,=9" : : : "d8"); \ + asm volatile ("vldr d9,=10" : : : "d9"); \ + asm volatile ("vldr d10,=11" : : : "d10"); \ + asm volatile ("vldr d11,=12" : : : "d11"); \ + asm volatile ("vldr d12,=13" : : : "d12"); \ + asm volatile ("vldr d13,=14" : : : "d13"); \ + asm volatile ("vldr d14,=15" : : : "d14"); \ + asm volatile ("vldr d15,=16" : : : "d15"); \ + } \ + if (hwcap & HWCAP_ARM_VFPD32) \ + { \ + SAVE_VFP_D32 \ + } + +# define VFP_STACK_REQ (16*8) +# if __BYTE_ORDER == __BIG_ENDIAN +# define DISP 7 +# else +# define DISP 0 +# endif + +# ifdef HAVE_ARM_PCS_VFP_D32 +# define CHECK_VFP_D32 \ + char vfp[VFP_STACK_REQ]; \ + asm volatile ("vstmia %0, {d16-d31}\n" \ + : \ + : "r" (vfp) \ + : "memory"); \ + \ + char expected[VFP_STACK_REQ] = { 0 }; \ + for (int i = 0; i < 16; ++i) \ + expected[i * 8 + DISP] = i + 17; \ + \ + if (memcmp (vfp, expected, VFP_STACK_REQ) != 0) \ + abort (); +# else +# define CHECK_VFP_D32 +# endif + +# define AFTER_TLSDESC_CALL() \ + if (hwcap & HWCAP_ARM_VFP) \ + { \ + char vfp[VFP_STACK_REQ]; \ + asm volatile ("vstmia %0, {d0-d15}\n" \ + : \ + : "r" (vfp) \ + : "memory"); \ + \ + char expected[VFP_STACK_REQ] = { 0 }; \ + for (int i = 0; i < 16; ++i) \ + expected[i * 8 + DISP] = i + 1; \ + \ + if (memcmp (vfp, expected, VFP_STACK_REQ) != 0) \ + abort (); \ + } \ + if (hwcap & HWCAP_ARM_VFPD32) \ + { \ + CHECK_VFP_D32 \ + } + +#endif /* __SOFTFP__ */ + +#include_next