diff options
Diffstat (limited to 'src/ppc32/Gstep.c')
| -rw-r--r-- | src/ppc32/Gstep.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/src/ppc32/Gstep.c b/src/ppc32/Gstep.c new file mode 100644 index 00000000..a5afe0ab --- /dev/null +++ b/src/ppc32/Gstep.c @@ -0,0 +1,317 @@ +/* libunwind - a platform-independent unwind library + Copyright (C) 2006-2007 IBM + Contributed by + Corey Ashford <cjashfor@us.ibm.com> + Jose Flavio Aguilar Paulino <jflavio@br.ibm.com> <joseflavio@gmail.com> + +This file is part of libunwind. + +Permission is hereby granted, free of charge, to any person obtaining +a copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be +included in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ + +#include "unwind_i.h" +#include "ucontext_i.h" +#include <signal.h> + +/* This definition originates in /usr/include/asm-ppc64/ptrace.h, but is + defined there only when __KERNEL__ is defined. We reproduce it here for + our use at the user level in order to locate the ucontext record, which + appears to be at this offset relative to the stack pointer when in the + context of the signal handler return trampoline code - + __kernel_sigtramp_rt64. */ +#define __SIGNAL_FRAMESIZE 128 + +/* This definition comes from the document "64-bit PowerPC ELF Application + Binary Interface Supplement 1.9", section 3.2.2. + http://www.linux-foundation.org/spec/ELF/ppc64/PPC-elf64abi-1.9.html#STACK */ + +typedef struct +{ + long unsigned back_chain; + long unsigned cr_save; + long unsigned lr_save; + /* many more fields here, but they are unused by this code */ +} stack_frame_t; + + +PROTECTED int +unw_step (unw_cursor_t * cursor) +{ + struct cursor *c = (struct cursor *) cursor; + stack_frame_t dummy; + unw_word_t back_chain_offset, lr_save_offset, v_regs_ptr; + struct dwarf_loc back_chain_loc, lr_save_loc, sp_loc, ip_loc, v_regs_loc; + int ret; + + Debug (1, "(cursor=%p, ip=0x%016lx)\n", c, (unsigned long) c->dwarf.ip); + + if (c->dwarf.ip == 0) + { + /* Unless the cursor or stack is corrupt or uninitialized, + we've most likely hit the top of the stack */ + return 0; + } + + /* Try DWARF-based unwinding... */ + + ret = dwarf_step (&c->dwarf); + + if (ret < 0 && ret != -UNW_ENOINFO) + { + Debug (2, "returning %d\n", ret); + return ret; + } + + if (unlikely (ret < 0)) + { + if (likely (!unw_is_signal_frame (cursor))) + { + /* DWARF unwinding failed. As of 09/26/2006, gcc in 64-bit mode + produces the mandatory level of traceback record in the code, but + I get the impression that this is transitory, that eventually gcc + will not produce any traceback records at all. So, for now, we + won't bother to try to find and use these records. + + We can, however, attempt to unwind the frame by using the callback + chain. This is very crude, however, and won't be able to unwind + any registers besides the IP, SP, and LR . */ + + back_chain_offset = ((void *) &dummy.back_chain - (void *) &dummy); + lr_save_offset = ((void *) &dummy.lr_save - (void *) &dummy); + + back_chain_loc = DWARF_LOC (c->dwarf.cfa + back_chain_offset, 0); + + if ((ret = + dwarf_get (&c->dwarf, back_chain_loc, &c->dwarf.cfa)) < 0) + { + Debug + ("Unable to retrieve CFA from back chain in stack frame - %d\n", + ret); + return ret; + } + if (c->dwarf.cfa == 0) + /* Unless the cursor or stack is corrupt or uninitialized we've most + likely hit the top of the stack */ + return 0; + + lr_save_loc = DWARF_LOC (c->dwarf.cfa + lr_save_offset, 0); + + if ((ret = dwarf_get (&c->dwarf, lr_save_loc, &c->dwarf.ip)) < 0) + { + Debug + ("Unable to retrieve IP from lr save in stack frame - %d\n", + ret); + return ret; + } + ret = 1; + } + else + { + /* Find the sigcontext record by taking the CFA and adjusting by + the dummy signal frame size. + + Note that there isn't any way to determined if SA_SIGINFO was + set in the sa_flags parameter to sigaction when the signal + handler was established. If it was not set, the ucontext + record is not required to be on the stack, in which case the + following code will likely cause a seg fault or other crash + condition. */ + + unw_word_t ucontext = c->dwarf.cfa + __SIGNAL_FRAMESIZE; + + Debug (1, "signal frame, skip over trampoline\n"); + + c->sigcontext_format = PPC_SCF_LINUX_RT_SIGFRAME; + c->sigcontext_addr = ucontext; + + sp_loc = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R1, 0); + ip_loc = DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_NIP, 0); + + ret = dwarf_get (&c->dwarf, sp_loc, &c->dwarf.cfa); + if (ret < 0) + { + Debug (2, "returning %d\n", ret); + return ret; + } + ret = dwarf_get (&c->dwarf, ip_loc, &c->dwarf.ip); + if (ret < 0) + { + Debug (2, "returning %d\n", ret); + return ret; + } + + /* Instead of just restoring the non-volatile registers, do all + of the registers for now. This will incur a performance hit, + but it's rare enough not to cause too much of a problem, and + might be useful in some cases. */ + c->dwarf.loc[UNW_PPC32_R0] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R0, 0); + c->dwarf.loc[UNW_PPC32_R1] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R1, 0); + c->dwarf.loc[UNW_PPC32_R2] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R2, 0); + c->dwarf.loc[UNW_PPC32_R3] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R3, 0); + c->dwarf.loc[UNW_PPC32_R4] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R4, 0); + c->dwarf.loc[UNW_PPC32_R5] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R5, 0); + c->dwarf.loc[UNW_PPC32_R6] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R6, 0); + c->dwarf.loc[UNW_PPC32_R7] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R7, 0); + c->dwarf.loc[UNW_PPC32_R8] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R8, 0); + c->dwarf.loc[UNW_PPC32_R9] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R9, 0); + c->dwarf.loc[UNW_PPC32_R10] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R10, 0); + c->dwarf.loc[UNW_PPC32_R11] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R11, 0); + c->dwarf.loc[UNW_PPC32_R12] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R12, 0); + c->dwarf.loc[UNW_PPC32_R13] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R13, 0); + c->dwarf.loc[UNW_PPC32_R14] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R14, 0); + c->dwarf.loc[UNW_PPC32_R15] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R15, 0); + c->dwarf.loc[UNW_PPC32_R16] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R16, 0); + c->dwarf.loc[UNW_PPC32_R17] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R17, 0); + c->dwarf.loc[UNW_PPC32_R18] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R18, 0); + c->dwarf.loc[UNW_PPC32_R19] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R19, 0); + c->dwarf.loc[UNW_PPC32_R20] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R20, 0); + c->dwarf.loc[UNW_PPC32_R21] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R21, 0); + c->dwarf.loc[UNW_PPC32_R22] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R22, 0); + c->dwarf.loc[UNW_PPC32_R23] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R23, 0); + c->dwarf.loc[UNW_PPC32_R24] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R24, 0); + c->dwarf.loc[UNW_PPC32_R25] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R25, 0); + c->dwarf.loc[UNW_PPC32_R26] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R26, 0); + c->dwarf.loc[UNW_PPC32_R27] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R27, 0); + c->dwarf.loc[UNW_PPC32_R28] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R28, 0); + c->dwarf.loc[UNW_PPC32_R29] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R29, 0); + c->dwarf.loc[UNW_PPC32_R30] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R30, 0); + c->dwarf.loc[UNW_PPC32_R31] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_R31, 0); + + c->dwarf.loc[UNW_PPC32_LR] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_LINK, 0); + c->dwarf.loc[UNW_PPC32_CTR] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_CTR, 0); + /* This CR0 assignment is probably wrong. There are 8 dwarf columns + assigned to the CR registers, but only one CR register in the + mcontext structure */ + c->dwarf.loc[UNW_PPC32_CR0] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_CCR, 0); + c->dwarf.loc[UNW_PPC32_XER] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_XER, 0); + c->dwarf.loc[UNW_PPC32_NIP] = + DWARF_LOC (ucontext + UC_MCONTEXT_GREGS_NIP, 0); + + /* TODO: Is there a way of obtaining the value of the + pseudo frame pointer (which is sp + some fixed offset, I + assume), based on the contents of the ucontext record + structure? For now, set this loc to null. */ + c->dwarf.loc[UNW_PPC32_FRAME_POINTER] = DWARF_NULL_LOC; + + c->dwarf.loc[UNW_PPC32_F0] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R0, 0); + c->dwarf.loc[UNW_PPC32_F1] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R1, 0); + c->dwarf.loc[UNW_PPC32_F2] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R2, 0); + c->dwarf.loc[UNW_PPC32_F3] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R3, 0); + c->dwarf.loc[UNW_PPC32_F4] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R4, 0); + c->dwarf.loc[UNW_PPC32_F5] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R5, 0); + c->dwarf.loc[UNW_PPC32_F6] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R6, 0); + c->dwarf.loc[UNW_PPC32_F7] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R7, 0); + c->dwarf.loc[UNW_PPC32_F8] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R8, 0); + c->dwarf.loc[UNW_PPC32_F9] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R9, 0); + c->dwarf.loc[UNW_PPC32_F10] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R10, 0); + c->dwarf.loc[UNW_PPC32_F11] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R11, 0); + c->dwarf.loc[UNW_PPC32_F12] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R12, 0); + c->dwarf.loc[UNW_PPC32_F13] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R13, 0); + c->dwarf.loc[UNW_PPC32_F14] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R14, 0); + c->dwarf.loc[UNW_PPC32_F15] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R15, 0); + c->dwarf.loc[UNW_PPC32_F16] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R16, 0); + c->dwarf.loc[UNW_PPC32_F17] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R17, 0); + c->dwarf.loc[UNW_PPC32_F18] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R18, 0); + c->dwarf.loc[UNW_PPC32_F19] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R19, 0); + c->dwarf.loc[UNW_PPC32_F20] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R20, 0); + c->dwarf.loc[UNW_PPC32_F21] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R21, 0); + c->dwarf.loc[UNW_PPC32_F22] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R22, 0); + c->dwarf.loc[UNW_PPC32_F23] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R23, 0); + c->dwarf.loc[UNW_PPC32_F24] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R24, 0); + c->dwarf.loc[UNW_PPC32_F25] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R25, 0); + c->dwarf.loc[UNW_PPC32_F26] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R26, 0); + c->dwarf.loc[UNW_PPC32_F27] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R27, 0); + c->dwarf.loc[UNW_PPC32_F28] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R28, 0); + c->dwarf.loc[UNW_PPC32_F29] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R29, 0); + c->dwarf.loc[UNW_PPC32_F30] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R30, 0); + c->dwarf.loc[UNW_PPC32_F31] = + DWARF_LOC (ucontext + UC_MCONTEXT_FREGS_R31, 0); + + ret = 1; + } + } + return ret; +} |