diff options
| -rw-r--r-- | debug/backtrace.c | 5 | ||||
| -rw-r--r-- | sysdeps/generic/unwind-arch.h | 30 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/mips/unwind-arch.h | 67 |
3 files changed, 102 insertions, 0 deletions
diff --git a/debug/backtrace.c b/debug/backtrace.c index cc4b9a5..69cf4c2 100644 --- a/debug/backtrace.c +++ b/debug/backtrace.c @@ -23,6 +23,7 @@ #include <gnu/lib-names.h> #include <stdlib.h> #include <unwind.h> +#include <unwind-arch.h> struct trace_arg { @@ -78,6 +79,10 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a) if (arg->cnt != -1) { arg->array[arg->cnt] = (void *) unwind_getip (ctx); + if (arg->cnt > 0) + arg->array[arg->cnt] + = unwind_arch_adjustment (arg->array[arg->cnt - 1], + arg->array[arg->cnt]); /* Check whether we make any progress. */ _Unwind_Word cfa = unwind_getcfa (ctx); diff --git a/sysdeps/generic/unwind-arch.h b/sysdeps/generic/unwind-arch.h new file mode 100644 index 0000000..d712e5e --- /dev/null +++ b/sysdeps/generic/unwind-arch.h @@ -0,0 +1,30 @@ +/* Return backtrace of current program state. Arch-specific bits. + Copyright (C) 2020 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 + <https://www.gnu.org/licenses/>. */ + +#ifndef _UNWIND_ARCH_H +#define _UNWIND_ARCH_H + +#include <unwind.h> + +static inline void * +unwind_arch_adjustment (void *prev, void *addr) +{ + return addr; +} + +#endif diff --git a/sysdeps/unix/sysv/linux/mips/unwind-arch.h b/sysdeps/unix/sysv/linux/mips/unwind-arch.h new file mode 100644 index 0000000..a009899 --- /dev/null +++ b/sysdeps/unix/sysv/linux/mips/unwind-arch.h @@ -0,0 +1,67 @@ +/* Return backtrace of current program state. Arch-specific bits. + Copyright (C) 2020 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 + <https://www.gnu.org/licenses/>. */ + +#ifndef _UNWIND_ARCH_H +#define _UNWIND_ARCH_H + +#include <stdint.h> + +/* MIPS fallback code handle a frame where its FDE can not be obtained + (for instance a signal frame) by reading the kernel allocated signal frame + and adding '2' to the value of 'sc_pc' [1]. The added value is used to + recognize an end of an EH region on mips16 [2]. + + The idea here is to adjust the obtained signal frame ADDR value and remove + the libgcc added value by checking if the previous frame is a signal frame + one. + + [1] libgcc/config/mips/linux-unwind.h from gcc code. + [2] gcc/config/mips/mips.h from gcc code. */ + +static inline void * +unwind_arch_adjustment (void *prev, void *addr) +{ + uint32_t *pc = (uint32_t *) prev; + + if (pc == NULL) + return addr; + + /* For MIPS16 or microMIPS frame libgcc makes no adjustment. */ + if ((uintptr_t) pc & 0x3) + return addr; + + /* The vDSO containes either + + 24021061 li v0, 0x1061 (rt_sigreturn) + 0000000c syscall + or + 24021017 li v0, 0x1017 (sigreturn) + 0000000c syscall */ + if (pc[1] != 0x0000000c) + return addr; +#if _MIPS_SIM == _ABIO32 + if (pc[0] == (0x24020000 | __NR_sigreturn)) + return (void *) ((uintptr_t) addr - 2); +#endif + if (pc[0] == (0x24020000 | __NR_rt_sigreturn)) + return (void *) ((uintptr_t) addr - 2); + + return addr; +} + +#endif |