diff options
Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/powerpc64/backtrace.c')
| -rw-r--r-- | REORG.TODO/sysdeps/powerpc/powerpc64/backtrace.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/powerpc64/backtrace.c b/REORG.TODO/sysdeps/powerpc/powerpc64/backtrace.c new file mode 100644 index 0000000000..723948d78f --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/powerpc64/backtrace.c @@ -0,0 +1,104 @@ +/* Return backtrace of current program state. + Copyright (C) 1998-2017 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#include <stddef.h> +#include <string.h> +#include <signal.h> +#include <stdint.h> + +#include <execinfo.h> +#include <libc-vdso.h> + +/* This is the stack layout we see with every stack frame. + Note that every routine is required by the ABI to lay out the stack + like this. + + +----------------+ +-----------------+ + %r1 -> | %r1 last frame--------> | %r1 last frame--->... --> NULL + | | | | + | cr save | | cr save | + | | | | + | (unused) | | return address | + +----------------+ +-----------------+ +*/ +struct layout +{ + struct layout *next; + long int condition_register; + void *return_address; +}; + +/* Since the signal handler is just like any other function it needs to + save/restore its LR and it will save it into callers stack frame. + Since a signal handler doesn't have a caller, the kernel creates a + dummy frame to make it look like it has a caller. */ +struct signal_frame_64 { +#define SIGNAL_FRAMESIZE 128 + char dummy[SIGNAL_FRAMESIZE]; + struct ucontext uc; + /* We don't care about the rest, since the IP value is at 'uc' field. */ +}; + +static inline int +is_sigtramp_address (void *nip) +{ +#ifdef SHARED + if (nip == VDSO_SYMBOL (sigtramp_rt64)) + return 1; +#endif + return 0; +} + +int +__backtrace (void **array, int size) +{ + struct layout *current; + int count; + + /* Force gcc to spill LR. */ + asm volatile ("" : "=l"(current)); + + /* Get the address on top-of-stack. */ + asm volatile ("ld %0,0(1)" : "=r"(current)); + + for ( count = 0; + current != NULL && count < size; + current = current->next, count++) + { + array[count] = current->return_address; + + /* Check if the symbol is the signal trampoline and get the interrupted + * symbol address from the trampoline saved area. */ + if (is_sigtramp_address (current->return_address)) + { + struct signal_frame_64 *sigframe = (struct signal_frame_64*) current; + array[++count] = (void*) sigframe->uc.uc_mcontext.gp_regs[PT_NIP]; + current = (void*) sigframe->uc.uc_mcontext.gp_regs[PT_R1]; + } + } + + /* It's possible the second-last stack frame can't return + (that is, it's __libc_start_main), in which case + the CRT startup code will have set its LR to 'NULL'. */ + if (count > 0 && array[count-1] == NULL) + count--; + + return count; +} +weak_alias (__backtrace, backtrace) +libc_hidden_def (__backtrace) |