diff options
Diffstat (limited to 'REORG.TODO/sysdeps/s390/s390-32/backtrace.c')
| -rw-r--r-- | REORG.TODO/sysdeps/s390/s390-32/backtrace.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/s390/s390-32/backtrace.c b/REORG.TODO/sysdeps/s390/s390-32/backtrace.c new file mode 100644 index 0000000000..705b05d139 --- /dev/null +++ b/REORG.TODO/sysdeps/s390/s390-32/backtrace.c @@ -0,0 +1,148 @@ +/* Return backtrace of current program state. + Copyright (C) 2000-2017 Free Software Foundation, Inc. + Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>. + 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 + <http://www.gnu.org/licenses/>. */ + +#include <libc-lock.h> +#include <dlfcn.h> +#include <execinfo.h> +#include <stddef.h> +#include <stdlib.h> +#include <unwind.h> + +/* This is a global variable set at program start time. It marks the + highest used stack address. */ +extern void *__libc_stack_end; + + +/* This is the stack layout we see for every non-leaf function. + size offset + %r15 -> +------------------+ + 4 | back chain | 0 + 4 | end of stack | 4 + 8 | glue | 8 + 8 | scratch | 16 + 40 | save area r6-r15 | 24 + 16 | save area f4,f6 | 64 + 16 | empty | 80 + +------------------+ + r14 in the save area holds the return address. +*/ + +struct layout +{ + int back_chain; + int end_of_stack; + int glue[2]; + int scratch[2]; + int save_grps[10]; + int save_fp[4]; + int empty[2]; +}; + +struct trace_arg +{ + void **array; + int cnt, size; +}; + +#ifdef SHARED +static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *); +static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *); + +static void +init (void) +{ + void *handle = __libc_dlopen ("libgcc_s.so.1"); + + if (handle == NULL) + return; + + unwind_backtrace = __libc_dlsym (handle, "_Unwind_Backtrace"); + unwind_getip = __libc_dlsym (handle, "_Unwind_GetIP"); + if (unwind_getip == NULL) + unwind_backtrace = NULL; +} + +static int +__backchain_backtrace (void **array, int size) +{ + /* We assume that all the code is generated with frame pointers set. */ + struct layout *stack; + int cnt = 0; + + __asm__ ("LR %0,%%r15" : "=d" (stack) ); + /* We skip the call to this function, it makes no sense to record it. */ + stack = (struct layout *) stack->back_chain; + while (cnt < size) + { + if (stack == NULL || (void *) stack > __libc_stack_end) + /* This means the address is out of range. Note that for the + toplevel we see a frame pointer with value NULL which clearly is + out of range. */ + break; + + array[cnt++] = (void *) (stack->save_grps[8] & 0x7fffffff); + + stack = (struct layout *) stack->back_chain; + } + + return cnt; +} +#else +# define unwind_backtrace _Unwind_Backtrace +# define unwind_getip _Unwind_GetIP +#endif + +static _Unwind_Reason_Code +backtrace_helper (struct _Unwind_Context *ctx, void *a) +{ + struct trace_arg *arg = a; + + /* We are first called with address in the __backtrace function. + Skip it. */ + if (arg->cnt != -1) + arg->array[arg->cnt] = (void *) unwind_getip (ctx); + if (++arg->cnt == arg->size) + return _URC_END_OF_STACK; + return _URC_NO_REASON; +} + +int +__backtrace (void **array, int size) +{ + struct trace_arg arg = { .array = array, .size = size, .cnt = -1 }; + + if (size <= 0) + return 0; + +#ifdef SHARED + __libc_once_define (static, once); + + __libc_once (once, init); + + if (unwind_backtrace == NULL) + return __backchain_backtrace (array, size); +#endif + + unwind_backtrace (backtrace_helper, &arg); + + return arg.cnt != -1 ? arg.cnt : 0; +} + +weak_alias (__backtrace, backtrace) +libc_hidden_def (__backtrace) |