diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/backtrace.c | 117 |
1 files changed, 0 insertions, 117 deletions
diff --git a/sysdeps/powerpc/powerpc64/backtrace.c b/sysdeps/powerpc/powerpc64/backtrace.c deleted file mode 100644 index 37de9b5bdd..0000000000 --- a/sysdeps/powerpc/powerpc64/backtrace.c +++ /dev/null @@ -1,117 +0,0 @@ -/* Return backtrace of current program state. - Copyright (C) 1998-2021 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 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 <https://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]; - ucontext_t uc; - /* We don't care about the rest, since the IP value is at 'uc' field. */ -}; - -/* Test if the address match to the inside the trampoline code. - Up to and including kernel 5.8, returning from an interrupt or syscall to a - signal handler starts execution directly at the handler's entry point, with - LR set to address of the sigreturn trampoline (the vDSO symbol). - Newer kernels will branch to signal handler from the trampoline instead, so - checking the stacktrace against the vDSO entrypoint does not work in such - case. - The vDSO branches with a 'bctrl' instruction, so checking either the - vDSO address itself and the next instruction should cover all kernel - versions. */ -static inline bool -is_sigtramp_address (void *nip) -{ -#ifdef HAVE_SIGTRAMP_RT64 - if (nip == GLRO (dl_vdso_sigtramp_rt64) || - nip == GLRO (dl_vdso_sigtramp_rt64) + 4) - return true; -#endif - return false; -} - -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; - if (count + 1 == size) - break; - 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) |