Date: Fri, 7 Jul 2023 16:56:23 GMT From: Dmitry Chagin <dchagin@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: bae6bb0698ee - main - csu: Implement _start using as to satisfy unwinders on aarch64 Message-ID: <202307071656.367GuNr7013899@gitrepo.freebsd.org>
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The branch main has been updated by dchagin: URL: https://cgit.FreeBSD.org/src/commit/?id=bae6bb0698ee727df601e4418153787b5b4b0c9d commit bae6bb0698ee727df601e4418153787b5b4b0c9d Author: Dmitry Chagin <dchagin@FreeBSD.org> AuthorDate: 2023-07-07 16:56:02 +0000 Commit: Dmitry Chagin <dchagin@FreeBSD.org> CommitDate: 2023-07-07 16:56:02 +0000 csu: Implement _start using as to satisfy unwinders on aarch64 The right unwinding stop indicator should be CFI-undefined PC. https://dwarfstd.org/doc/Dwarf3.pdf - page 118: If a Return Address register is defined in the virtual unwind table, and its rule is undefined (for example, by DW_CFA_undefined), then there is no return address and no call address, and the virtual unwind of stack activations is complete. Reviewed by: Differential Revision: https://reviews.freebsd.org/D40623 --- lib/csu/aarch64/Makefile | 3 ++- lib/csu/aarch64/crt1_c.c | 15 --------------- lib/csu/aarch64/crt1_s.S | 24 +++++++++++++++++++++++- 3 files changed, 25 insertions(+), 17 deletions(-) diff --git a/lib/csu/aarch64/Makefile b/lib/csu/aarch64/Makefile index d8d0d3fd8f99..72be8b70ef19 100644 --- a/lib/csu/aarch64/Makefile +++ b/lib/csu/aarch64/Makefile @@ -4,6 +4,7 @@ CFLAGS+= -I${.CURDIR} -CRT1OBJS+= crt1_s.o +CRT1SRC= crt1_s.S +CRT1OBJ= crt1_c.o .include <bsd.lib.mk> diff --git a/lib/csu/aarch64/crt1_c.c b/lib/csu/aarch64/crt1_c.c index 7f4fea37ba1a..095c798046b4 100644 --- a/lib/csu/aarch64/crt1_c.c +++ b/lib/csu/aarch64/crt1_c.c @@ -32,19 +32,4 @@ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); -#include "libc_private.h" #include "csu_common.h" - -void __start(int, char **, char **, void (*)(void)) __dead2; - -/* The entry function. */ -void -__start(int argc, char *argv[], char *env[], void (*cleanup)(void)) -{ -#ifdef GCRT - __libc_start1_gcrt(argc, argv, env, cleanup, main, &eprol, &etext); -__asm__("eprol:"); -#else - __libc_start1(argc, argv, env, cleanup, main); -#endif -} diff --git a/lib/csu/aarch64/crt1_s.S b/lib/csu/aarch64/crt1_s.S index 65803c8246ae..17ed74531675 100644 --- a/lib/csu/aarch64/crt1_s.S +++ b/lib/csu/aarch64/crt1_s.S @@ -32,13 +32,35 @@ #include <machine/asm.h> __FBSDID("$FreeBSD$"); + /* + * The program entry point + * void _start(char **ap, void (*cleanup)(void)) __dead2 + */ ENTRY(_start) + .cfi_undefined x30 mov x3, x2 /* cleanup */ add x1, x0, #8 /* load argv */ ldr x0, [x0] /* load argc */ add x2, x1, x0, lsl #3 /* env is after argv */ add x2, x2, #8 /* argv is null terminated */ - b __start +#ifdef PIC + adrp x4, main + add x4, x4, :lo12:main +#else + ldr x4, =main +#endif +#ifdef GCRT + ldr x5, =eprol + ldr x6, =etext + /* + * __libc_start1_gcrt(argc, argv, env, cleanup, main, &eprol, &etext) + */ + bl __libc_start1_gcrt +eprol: +#else + /* __libc_start1(argc, argv, env, cleanup, main) */ + bl __libc_start1 +#endif END(_start) .section .note.GNU-stack,"",@progbits
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