diff options
Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/powerpc32/backtrace.c')
| -rw-r--r-- | REORG.TODO/sysdeps/powerpc/powerpc32/backtrace.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/powerpc32/backtrace.c b/REORG.TODO/sysdeps/powerpc/powerpc32/backtrace.c new file mode 100644 index 0000000000..394062136c --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/powerpc32/backtrace.c @@ -0,0 +1,131 @@ +/* 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 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 <execinfo.h> +#include <stddef.h> +#include <string.h> +#include <signal.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 + | | | | + | (unused) | | return address | + +----------------+ +-----------------+ +*/ +struct layout +{ + struct layout *next; + void *return_address; +}; + +#define SIGNAL_FRAMESIZE 64 + +/* 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_32 { + char dummy[SIGNAL_FRAMESIZE]; + struct sigcontext sctx; + mcontext_t mctx; + /* We don't care about the rest, since IP value is at 'mctx' field. */ +}; + +static inline int +is_sigtramp_address (void *nip) +{ +#ifdef SHARED + if (nip == VDSO_SYMBOL (sigtramp32)) + return 1; +#endif + return 0; +} + +struct rt_signal_frame_32 { + char dummy[SIGNAL_FRAMESIZE + 16]; + siginfo_t info; + struct ucontext uc; + /* We don't care about the rest, since IP value is at 'uc' field. */ +}; + +static inline int +is_sigtramp_address_rt (void * nip) +{ +#ifdef SHARED + if (nip == VDSO_SYMBOL (sigtramp_rt32)) + 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 ("lwz %0,0(1)" : "=r"(current)); + + for ( count = 0; + current != NULL && count < size; + current = current->next, count++) + { + gregset_t *gregset = NULL; + + 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_32 *sigframe = + (struct signal_frame_32*) current; + gregset = &sigframe->mctx.gregs; + } + else if (is_sigtramp_address_rt (current->return_address)) + { + struct rt_signal_frame_32 *sigframe = + (struct rt_signal_frame_32*) current; + gregset = &sigframe->uc.uc_mcontext.uc_regs->gregs; + } + if (gregset) + { + array[++count] = (void*)((*gregset)[PT_NIP]); + current = (void*)((*gregset)[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) |