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author | Florian Weimer <fweimer@redhat.com> | 2021-03-01 15:56:36 +0100 |
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committer | Florian Weimer <fweimer@redhat.com> | 2021-03-01 16:00:03 +0100 |
commit | 6b7efa3d8703cfd020281706f8110bc4a41b1525 (patch) | |
tree | 5729f22a50df964ba95c32e84279fe539133febf /sysdeps/arm | |
parent | d14624825a3eeb7712ffbe6e794cea1c5636de4d (diff) | |
download | glibc-6b7efa3d8703cfd020281706f8110bc4a41b1525.tar.gz glibc-6b7efa3d8703cfd020281706f8110bc4a41b1525.tar.xz glibc-6b7efa3d8703cfd020281706f8110bc4a41b1525.zip |
Implement _Unwind_Resume in libc on top of <unwind-link.h>
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. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps/arm')
-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 |
4 files changed, 88 insertions, 15 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); +} |