diff options
Diffstat (limited to 'libunwind/src/libunwind.cpp')
| -rw-r--r-- | libunwind/src/libunwind.cpp | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/libunwind/src/libunwind.cpp b/libunwind/src/libunwind.cpp index cf39ec5..951d87d 100644 --- a/libunwind/src/libunwind.cpp +++ b/libunwind/src/libunwind.cpp @@ -118,14 +118,52 @@ _LIBUNWIND_HIDDEN int __unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum, typedef LocalAddressSpace::pint_t pint_t; AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; if (co->validReg(regNum)) { - co->setReg(regNum, (pint_t)value); // special case altering IP to re-find info (being called by personality // function) if (regNum == UNW_REG_IP) { unw_proc_info_t info; // First, get the FDE for the old location and then update it. co->getInfo(&info); - co->setInfoBasedOnIPRegister(false); + + pint_t sp = (pint_t)co->getReg(UNW_REG_SP); + +#if defined(_LIBUNWIND_TARGET_AARCH64_AUTHENTICATED_UNWINDING) + { + // It is only valid to set the IP within the current function. This is + // important for ptrauth, otherwise the IP cannot be correctly signed. + // The current signature of `value` is via the schema: + // __ptrauth(ptrauth_key_return_address, <<sp>>, 0) + // For this to be generally usable we manually re-sign it to the + // directly supported schema: + // __ptrauth(ptrauth_key_return_address, 1, 0) + unw_word_t + __unwind_ptrauth_restricted_intptr(ptrauth_key_return_address, 1, + 0) authenticated_value; + unw_word_t opaque_value = (uint64_t)ptrauth_auth_and_resign( + (void *)value, ptrauth_key_return_address, sp, + ptrauth_key_return_address, &authenticated_value); + memmove(reinterpret_cast<void *>(&authenticated_value), + reinterpret_cast<void *>(&opaque_value), + sizeof(authenticated_value)); + if (authenticated_value < info.start_ip || + authenticated_value > info.end_ip) + _LIBUNWIND_ABORT("PC vs frame info mismatch"); + + // PC should have been signed with the sp, so we verify that + // roundtripping does not fail. + pint_t pc = (pint_t)co->getReg(UNW_REG_IP); + if (ptrauth_auth_and_resign((void *)pc, ptrauth_key_return_address, sp, + ptrauth_key_return_address, + sp) != (void *)pc) { + _LIBUNWIND_LOG("Bad unwind through arm64e (0x%zX, 0x%zX)->0x%zX\n", + pc, sp, + (pint_t)ptrauth_auth_data( + (void *)pc, ptrauth_key_return_address, sp)); + _LIBUNWIND_ABORT("Bad unwind through arm64e"); + } + } +#endif + // If the original call expects stack adjustment, perform this now. // Normal frame unwinding would have included the offset already in the // CFA computation. @@ -133,7 +171,11 @@ _LIBUNWIND_HIDDEN int __unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum, // this should actually be - info.gp. LLVM doesn't currently support // any such platforms and Clang doesn't export a macro for them. if (info.gp) - co->setReg(UNW_REG_SP, co->getReg(UNW_REG_SP) + info.gp); + co->setReg(UNW_REG_SP, sp + info.gp); + co->setReg(UNW_REG_IP, value); + co->setInfoBasedOnIPRegister(false); + } else { + co->setReg(regNum, (pint_t)value); } return UNW_ESUCCESS; } |