diff options
| -rw-r--r-- | sysdeps/arm/arm-unwind-resume.S | 26 | ||||
| -rw-r--r-- | sysdeps/arm/pt-arm-unwind-resume.S | 48 | ||||
| -rw-r--r-- | sysdeps/arm/unwind-arch.h | 4 | ||||
| -rw-r--r-- | sysdeps/arm/unwind-resume.c | 25 | ||||
| -rw-r--r-- | sysdeps/generic/unwind-resume.c | 55 |
5 files changed, 97 insertions, 61 deletions
diff --git a/sysdeps/arm/arm-unwind-resume.S b/sysdeps/arm/arm-unwind-resume.S index 22525f4db0..92c171fe0f 100644 --- a/sysdeps/arm/arm-unwind-resume.S +++ b/sysdeps/arm/arm-unwind-resume.S @@ -18,29 +18,29 @@ #include <sysdep.h> -/* This is just implementing exactly what the C version does. +/* This is equivalent to the following C implementation: + + void + _Unwind_Resume (struct _Unwind_Exception *exc) + { + __unwind_link_get_resume () (exc); + } + We do it in assembly just to ensure that we get an unmolested tail call to the libgcc function, which is necessary for the ARM unwinder. */ ENTRY (_Unwind_Resume) - LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) - cmp ip, #0 - beq 1f -0: PTR_DEMANGLE (ip, ip, r2, r3) - bx ip - /* We need to save and restore LR (for our own return address) and R0 (for the argument to _Unwind_Resume) around the call. */ -1: push {r0, lr} + push {r0, lr} cfi_adjust_cfa_offset (8) cfi_rel_offset (r0, 0) cfi_rel_offset (lr, 4) - bl __libgcc_s_init + bl __unwind_link_get_resume + mov r3, r0 pop {r0, lr} cfi_adjust_cfa_offset (-8) - cfi_restore (r0) + cfi_restore (r4) cfi_restore (lr) - - LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) - b 0b + bx r3 END (_Unwind_Resume) diff --git a/sysdeps/arm/pt-arm-unwind-resume.S b/sysdeps/arm/pt-arm-unwind-resume.S index 7cb555c02b..d579848696 100644 --- a/sysdeps/arm/pt-arm-unwind-resume.S +++ b/sysdeps/arm/pt-arm-unwind-resume.S @@ -1,2 +1,46 @@ -#define __libgcc_s_init pthread_cancel_init -#include <arm-unwind-resume.S> +/* _Unwind_Resume wrapper for ARM EABI. + Copyright (C) 2015-2021 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 + <https://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +/* This is just implementing exactly what the C version does. + We do it in assembly just to ensure that we get an unmolested tail + call to the libgcc function, which is necessary for the ARM unwinder. */ + +ENTRY (_Unwind_Resume) + LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) + cmp ip, #0 + beq 1f +0: PTR_DEMANGLE (ip, ip, r2, r3) + bx ip + + /* We need to save and restore LR (for our own return address) + and R0 (for the argument to _Unwind_Resume) around the call. */ +1: push {r0, lr} + cfi_adjust_cfa_offset (8) + cfi_rel_offset (r0, 0) + cfi_rel_offset (lr, 4) + bl pthread_cancel_init + pop {r0, lr} + cfi_adjust_cfa_offset (-8) + cfi_restore (r0) + cfi_restore (lr) + + LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) + b 0b +END (_Unwind_Resume) diff --git a/sysdeps/arm/unwind-arch.h b/sysdeps/arm/unwind-arch.h index fcf889b3c7..62f643b221 100644 --- a/sysdeps/arm/unwind-arch.h +++ b/sysdeps/arm/unwind-arch.h @@ -32,4 +32,8 @@ assert (local.ptr__Unwind_VRS_Get != NULL); \ PTR_MANGLE (local.ptr__Unwind_VRS_Get); +/* This is used by the _Unwind_Resume assembler implementation to + obtain the address to jump to. */ +void *__unwind_link_get_resume (void) attribute_hidden; + #endif /* _ARCH_UNWIND_LINK_H */ diff --git a/sysdeps/arm/unwind-resume.c b/sysdeps/arm/unwind-resume.c new file mode 100644 index 0000000000..169d5c30e6 --- /dev/null +++ b/sysdeps/arm/unwind-resume.c @@ -0,0 +1,25 @@ +/* Unwinder function forwarders for libc. Arm version. + Copyright (C) 2021 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; see the file COPYING.LIB. If + not, see <https://www.gnu.org/licenses/>. */ + +#include <sysdeps/generic/unwind-resume.c> + +void * +__unwind_link_get_resume (void) +{ + return UNWIND_LINK_PTR (link (), _Unwind_Resume); +} diff --git a/sysdeps/generic/unwind-resume.c b/sysdeps/generic/unwind-resume.c index 09533d6992..9e63762bf1 100644 --- a/sysdeps/generic/unwind-resume.c +++ b/sysdeps/generic/unwind-resume.c @@ -16,68 +16,31 @@ License along with the GNU C Library; see the file COPYING.LIB. If not, see <https://www.gnu.org/licenses/>. */ -#include <dlfcn.h> #include <stdio.h> -#include <unwind.h> #include <gnu/lib-names.h> +#include <unwind-link.h> #include <sysdep.h> #include <unwind-resume.h> - -void (*__libgcc_s_resume) (struct _Unwind_Exception *exc) - attribute_hidden __attribute__ ((noreturn)); - -static _Unwind_Reason_Code (*libgcc_s_personality) PERSONALITY_PROTO; - -void attribute_hidden __attribute__ ((cold)) -__libgcc_s_init (void) +static struct unwind_link * +link (void) { - void *resume, *personality; - void *handle; - - /* See include/dlfcn.h. Use of __libc_dlopen requires RTLD_NOW. */ - handle = __libc_dlopen (LIBGCC_S_SO); - - if (handle == NULL - || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL - || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL) - __libc_fatal (LIBGCC_S_SO - " must be installed for unwinding to work\n"); - -#ifdef PTR_MANGLE - PTR_MANGLE (resume); -#endif - __libgcc_s_resume = resume; -#ifdef PTR_MANGLE - PTR_MANGLE (personality); -#endif - libgcc_s_personality = personality; + struct unwind_link *unwind_link = __libc_unwind_link_get (); + if (unwind_link == NULL) + __libc_fatal (LIBGCC_S_SO " must be installed for unwinding to work\n"); + return unwind_link; } #if !HAVE_ARCH_UNWIND_RESUME void _Unwind_Resume (struct _Unwind_Exception *exc) { - if (__glibc_unlikely (__libgcc_s_resume == NULL)) - __libgcc_s_init (); - - __typeof (__libgcc_s_resume) resume = __libgcc_s_resume; -#ifdef PTR_DEMANGLE - PTR_DEMANGLE (resume); -#endif - (*resume) (exc); + UNWIND_LINK_PTR (link (), _Unwind_Resume) (exc); } #endif _Unwind_Reason_Code __gcc_personality_v0 PERSONALITY_PROTO { - if (__glibc_unlikely (libgcc_s_personality == NULL)) - __libgcc_s_init (); - - __typeof (libgcc_s_personality) personality = libgcc_s_personality; -#ifdef PTR_DEMANGLE - PTR_DEMANGLE (personality); -#endif - return (*personality) PERSONALITY_ARGS; + return UNWIND_LINK_PTR (link (), personality) PERSONALITY_ARGS; } |