diff options
Diffstat (limited to 'ports/sysdeps/unix/sysv/linux/arm/nptl/unwind-forcedunwind.c')
| -rw-r--r-- | ports/sysdeps/unix/sysv/linux/arm/nptl/unwind-forcedunwind.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/nptl/unwind-forcedunwind.c b/ports/sysdeps/unix/sysv/linux/arm/nptl/unwind-forcedunwind.c new file mode 100644 index 0000000000..29e2c2b00b --- /dev/null +++ b/ports/sysdeps/unix/sysv/linux/arm/nptl/unwind-forcedunwind.c @@ -0,0 +1,158 @@ +/* Copyright (C) 2003, 2005, 2007, 2009, 2010 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>. + + 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 + <http://www.gnu.org/licenses/>. */ + +#include <dlfcn.h> +#include <stdio.h> +#include <unwind.h> +#include <pthreadP.h> + +static void *libgcc_s_handle; +static void (*libgcc_s_resume) (struct _Unwind_Exception *exc); +static _Unwind_Reason_Code (*libgcc_s_personality) + (_Unwind_State, struct _Unwind_Exception *, struct _Unwind_Context *); +static _Unwind_Reason_Code (*libgcc_s_forcedunwind) + (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); +static _Unwind_Word (*libgcc_s_getcfa) (struct _Unwind_Context *); + +void +__attribute_noinline__ +pthread_cancel_init (void) +{ + void *resume, *personality, *forcedunwind, *getcfa; + void *handle; + + if (__builtin_expect (libgcc_s_handle != NULL, 1)) + { + /* Force gcc to reload all values. */ + asm volatile ("" ::: "memory"); + return; + } + + handle = __libc_dlopen ("libgcc_s.so.1"); + + if (handle == NULL + || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL + || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL + || (forcedunwind = __libc_dlsym (handle, "_Unwind_ForcedUnwind")) + == NULL + || (getcfa = __libc_dlsym (handle, "_Unwind_GetCFA")) == NULL +#ifdef ARCH_CANCEL_INIT + || ARCH_CANCEL_INIT (handle) +#endif + ) + __libc_fatal ("libgcc_s.so.1 must be installed for pthread_cancel to work\n"); + + libgcc_s_resume = resume; + libgcc_s_personality = personality; + libgcc_s_forcedunwind = forcedunwind; + libgcc_s_getcfa = getcfa; + /* Make sure libgcc_s_getcfa is written last. Otherwise, + pthread_cancel_init might return early even when the pointer the + caller is interested in is not initialized yet. */ + atomic_write_barrier (); + libgcc_s_handle = handle; +} + +void +__libc_freeres_fn_section +__unwind_freeres (void) +{ + void *handle = libgcc_s_handle; + if (handle != NULL) + { + libgcc_s_handle = NULL; + __libc_dlclose (handle); + } +} + +/* It's vitally important that _Unwind_Resume not have a stack frame; the + ARM unwinder relies on register state at entrance. So we write this in + assembly. */ + +asm ( +" .globl _Unwind_Resume\n" +" .type _Unwind_Resume, %function\n" +"_Unwind_Resume:\n" +" .cfi_sections .debug_frame\n" +" " CFI_STARTPROC "\n" +" stmfd sp!, {r4, r5, r6, lr}\n" +" " CFI_ADJUST_CFA_OFFSET (16)" \n" +" " CFI_REL_OFFSET (r4, 0) "\n" +" " CFI_REL_OFFSET (r5, 4) "\n" +" " CFI_REL_OFFSET (r6, 8) "\n" +" " CFI_REL_OFFSET (lr, 12) "\n" +" " CFI_REMEMBER_STATE "\n" +" ldr r4, 1f\n" +" ldr r5, 2f\n" +"3: add r4, pc, r4\n" +" ldr r3, [r4, r5]\n" +" mov r6, r0\n" +" cmp r3, #0\n" +" beq 4f\n" +"5: mov r0, r6\n" +" ldmfd sp!, {r4, r5, r6, lr}\n" +" " CFI_ADJUST_CFA_OFFSET (-16) "\n" +" " CFI_RESTORE (r4) "\n" +" " CFI_RESTORE (r5) "\n" +" " CFI_RESTORE (r6) "\n" +" " CFI_RESTORE (lr) "\n" +" bx r3\n" +" " CFI_RESTORE_STATE "\n" +"4: bl pthread_cancel_init\n" +" ldr r3, [r4, r5]\n" +" b 5b\n" +" " CFI_ENDPROC "\n" +" .align 2\n" +#ifdef __thumb2__ +"1: .word _GLOBAL_OFFSET_TABLE_ - 3b - 4\n" +#else +"1: .word _GLOBAL_OFFSET_TABLE_ - 3b - 8\n" +#endif +"2: .word libgcc_s_resume(GOTOFF)\n" +" .size _Unwind_Resume, .-_Unwind_Resume\n" +); + +_Unwind_Reason_Code +__gcc_personality_v0 (_Unwind_State state, + struct _Unwind_Exception *ue_header, + struct _Unwind_Context *context) +{ + if (__builtin_expect (libgcc_s_personality == NULL, 0)) + pthread_cancel_init (); + + return libgcc_s_personality (state, ue_header, context); +} + +_Unwind_Reason_Code +_Unwind_ForcedUnwind (struct _Unwind_Exception *exc, _Unwind_Stop_Fn stop, + void *stop_argument) +{ + if (__builtin_expect (libgcc_s_forcedunwind == NULL, 0)) + pthread_cancel_init (); + + return libgcc_s_forcedunwind (exc, stop, stop_argument); +} + +_Unwind_Word +_Unwind_GetCFA (struct _Unwind_Context *context) +{ + if (__builtin_expect (libgcc_s_getcfa == NULL, 0)) + pthread_cancel_init (); + + return libgcc_s_getcfa (context); +} |