| Message ID | 0eb99b38cfa9be318413373f08da472caab51e52.1613577607.git.fweimer@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Unwinder interface consolidation | expand |
On 2/17/21 11:03 AM, Florian Weimer via Libc-alpha wrote: > Temporarily move the arm _Unwind_Resume implementation to the file > used by libpthread. It will be ported to <unwind-link.h> along with > the rest of nptl. LGTM. Reviewed-by: Carlos O'Donell <carlos@redhat.com> > --- > sysdeps/arm/arm-unwind-resume.S | 26 +++++++------- > sysdeps/arm/pt-arm-unwind-resume.S | 48 ++++++++++++++++++++++++-- > sysdeps/arm/unwind-arch.h | 4 +++ > sysdeps/arm/unwind-resume.c | 25 ++++++++++++++ > sysdeps/generic/unwind-resume.c | 55 +++++------------------------- > 5 files changed, 97 insertions(+), 61 deletions(-) > create mode 100644 sysdeps/arm/unwind-resume.c > > 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; > } >
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; }