diff options
Diffstat (limited to 'gcc_plugin/afl-gcc-pass.so.cc')
| -rw-r--r-- | gcc_plugin/afl-gcc-pass.so.cc | 601 |
1 files changed, 0 insertions, 601 deletions
diff --git a/gcc_plugin/afl-gcc-pass.so.cc b/gcc_plugin/afl-gcc-pass.so.cc deleted file mode 100644 index c5614aca..00000000 --- a/gcc_plugin/afl-gcc-pass.so.cc +++ /dev/null @@ -1,601 +0,0 @@ -// -// There are some TODOs in this file: -// - fix instrumentation via external call -// - fix inline instrumentation -// - implement instrument list feature -// - dont instrument blocks that are uninteresting -// - implement neverZero -// - -/* - american fuzzy lop++ - GCC instrumentation pass - --------------------------------------------- - - Written by Austin Seipp <aseipp@pobox.com> with bits from - Emese Revfy <re.emese@gmail.com> - - Fixed by Heiko Eißfeldt 2019-2020 for AFL++ - - GCC integration design is based on the LLVM design, which comes - from Laszlo Szekeres. Some of the boilerplate code below for - afl_pass to adapt to different GCC versions was taken from Emese - Revfy's Size Overflow plugin for GCC, licensed under the GPLv2/v3. - - (NOTE: this plugin code is under GPLv3, in order to comply with the - GCC runtime library exception, which states that you may distribute - "Target Code" from the compiler under a license of your choice, as - long as the "Compilation Process" is "Eligible", and contains no - GPL-incompatible software in GCC "during the process of - transforming high level code to target code". In this case, the - plugin will be used to generate "Target Code" during the - "Compilation Process", and thus it must be GPLv3 to be "eligible".) - - Copyright (C) 2015 Austin Seipp - - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation, either version 3 of the License, or - (at your option) any later version. - - This program 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 General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. - - */ - -#define BUILD_INLINE_INST - -#include "../include/config.h" -#include "../include/debug.h" - -/* clear helper macros AFL types pull in, which intervene with gcc-plugin - * headers from GCC-8 */ -#ifdef likely - #undef likely -#endif -#ifdef unlikely - #undef unlikely -#endif - -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> - -#include <list> -#include <string> -#include <fstream> - -#include <gcc-plugin.h> -#include <plugin-version.h> -#include <diagnostic.h> -#include <tree.h> -#include <tree-ssa.h> -#include <tree-pass.h> -#include <tree-ssa-alias.h> -#include <basic-block.h> -#include <gimple-expr.h> -#include <gimple.h> -#include <gimple-iterator.h> -#include <gimple-ssa.h> -#include <version.h> -#include <toplev.h> -#include <intl.h> -#include <context.h> -#include <stringpool.h> -#include <cgraph.h> -#include <cfgloop.h> - -/* -------------------------------------------------------------------------- */ -/* -- AFL instrumentation pass ---------------------------------------------- */ - -static int be_quiet = 0; -static unsigned int inst_ratio = 100; -static bool inst_ext = true; -static std::list<std::string> myInstrumentList; - -static unsigned int ext_call_instrument(function *fun) { - - /* Instrument all the things! */ - basic_block bb; - unsigned finst_blocks = 0; - unsigned fcnt_blocks = 0; - - tree fntype = build_function_type_list(void_type_node, /* return */ - uint32_type_node, /* args */ - NULL_TREE); /* done */ - tree fndecl = build_fn_decl("__afl_trace", fntype); - TREE_STATIC(fndecl) = 1; /* Defined elsewhere */ - TREE_PUBLIC(fndecl) = 1; /* Public */ - DECL_EXTERNAL(fndecl) = 1; /* External linkage */ - DECL_ARTIFICIAL(fndecl) = 1; /* Injected by compiler */ - - FOR_EACH_BB_FN(bb, fun) { - - gimple_seq fcall; - gimple_seq seq = NULL; - gimple_stmt_iterator bentry; - ++fcnt_blocks; - - // only instrument if this basic block is the destination of a previous - // basic block that has multiple successors - // this gets rid of ~5-10% of instrumentations that are unnecessary - // result: a little more speed and less map pollution - - int more_than_one = -1; - edge ep; - edge_iterator eip; - - FOR_EACH_EDGE(ep, eip, bb->preds) { - - int count = 0; - if (more_than_one == -1) more_than_one = 0; - - basic_block Pred = ep->src; - edge es; - edge_iterator eis; - FOR_EACH_EDGE(es, eis, Pred->succs) { - - basic_block Succ = es->dest; - if (Succ != NULL) count++; - - } - - if (count > 1) more_than_one = 1; - - } - - if (more_than_one != 1) continue; - - /* Bail on this block if we trip the specified ratio */ - if (R(100) >= inst_ratio) continue; - - /* Make up cur_loc */ - unsigned int rand_loc = R(MAP_SIZE); - tree cur_loc = build_int_cst(uint32_type_node, rand_loc); - - /* Update bitmap via external call */ - /* to quote: - * /+ Trace a basic block with some ID +/ - * void __afl_trace(u32 x); - */ - - fcall = gimple_build_call( - fndecl, 1, - cur_loc); /* generate the function _call_ to above built reference, with - *1* parameter -> the random const for the location */ - gimple_seq_add_stmt(&seq, fcall); /* and insert into a sequence */ - - /* Done - grab the entry to the block and insert sequence */ - bentry = gsi_after_labels(bb); - gsi_insert_seq_before(&bentry, seq, GSI_SAME_STMT); - - ++finst_blocks; - - } - - /* Say something nice. */ - if (!be_quiet) { - - if (!finst_blocks) - WARNF(G_("No instrumentation targets found in " cBRI "%s" cRST), - function_name(fun)); - else if (finst_blocks < fcnt_blocks) - OKF(G_("Instrumented %2u /%2u locations in " cBRI "%s" cRST), - finst_blocks, fcnt_blocks, function_name(fun)); - else - OKF(G_("Instrumented %2u locations in " cBRI "%s" cRST), finst_blocks, - function_name(fun)); - - } - - return 0; - -} - -static unsigned int inline_instrument(function *fun) { - - /* Instrument all the things! */ - basic_block bb; - unsigned finst_blocks = 0; - unsigned fcnt_blocks = 0; - tree one = build_int_cst(unsigned_char_type_node, 1); - // tree zero = build_int_cst(unsigned_char_type_node, 0); - - /* Set up global type declarations */ - tree map_type = build_pointer_type(unsigned_char_type_node); - tree map_ptr_g = - build_decl(UNKNOWN_LOCATION, VAR_DECL, - get_identifier_with_length("__afl_area_ptr", 14), map_type); - TREE_USED(map_ptr_g) = 1; - TREE_STATIC(map_ptr_g) = 1; /* Defined elsewhere */ - DECL_EXTERNAL(map_ptr_g) = 1; /* External linkage */ - DECL_PRESERVE_P(map_ptr_g) = 1; - DECL_ARTIFICIAL(map_ptr_g) = 1; /* Injected by compiler */ - rest_of_decl_compilation(map_ptr_g, 1, 0); - - tree prev_loc_g = build_decl(UNKNOWN_LOCATION, VAR_DECL, - get_identifier_with_length("__afl_prev_loc", 14), - uint32_type_node); - TREE_USED(prev_loc_g) = 1; - TREE_STATIC(prev_loc_g) = 1; /* Defined elsewhere */ - DECL_EXTERNAL(prev_loc_g) = 1; /* External linkage */ - DECL_PRESERVE_P(prev_loc_g) = 1; - DECL_ARTIFICIAL(prev_loc_g) = 1; /* Injected by compiler */ - set_decl_tls_model(prev_loc_g, TLS_MODEL_REAL); /* TLS attribute */ - rest_of_decl_compilation(prev_loc_g, 1, 0); - - FOR_EACH_BB_FN(bb, fun) { - - gimple_seq seq = NULL; - gimple_stmt_iterator bentry; - ++fcnt_blocks; - - // only instrument if this basic block is the destination of a previous - // basic block that has multiple successors - // this gets rid of ~5-10% of instrumentations that are unnecessary - // result: a little more speed and less map pollution - - int more_than_one = -1; - edge ep; - edge_iterator eip; - FOR_EACH_EDGE(ep, eip, bb->preds) { - - int count = 0; - if (more_than_one == -1) more_than_one = 0; - - basic_block Pred = ep->src; - edge es; - edge_iterator eis; - FOR_EACH_EDGE(es, eis, Pred->succs) { - - basic_block Succ = es->dest; - if (Succ != NULL) count++; - - } - - if (count > 1) more_than_one = 1; - - } - - if (more_than_one != 1) continue; - - /* Bail on this block if we trip the specified ratio */ - if (R(100) >= inst_ratio) continue; - - /* Make up cur_loc */ - - unsigned int rand_loc = R(MAP_SIZE); - tree cur_loc = build_int_cst(uint32_type_node, rand_loc); - - /* Load prev_loc, xor with cur_loc */ - // gimple_assign <var_decl, prev_loc.0_1, prev_loc, NULL, NULL> - tree prev_loc = create_tmp_var_raw(uint32_type_node, "prev_loc"); - gassign *g = gimple_build_assign(prev_loc, VAR_DECL, prev_loc_g); - gimple_seq_add_stmt(&seq, g); // load prev_loc - update_stmt(g); - - // gimple_assign <bit_xor_expr, _2, prev_loc.0_1, 47231, NULL> - tree area_off = create_tmp_var_raw(uint32_type_node, "area_off"); - g = gimple_build_assign(area_off, BIT_XOR_EXPR, prev_loc, cur_loc); - gimple_seq_add_stmt(&seq, g); // area_off = prev_loc ^ cur_loc - update_stmt(g); - - /* Update bitmap */ - - // gimple_assign <addr_expr, p_6, &map[_2], NULL, NULL> - tree map_ptr = create_tmp_var(map_type, "map_ptr"); - tree map_ptr2 = create_tmp_var(map_type, "map_ptr2"); - - g = gimple_build_assign(map_ptr, map_ptr_g); - gimple_seq_add_stmt(&seq, g); // map_ptr = __afl_area_ptr - update_stmt(g); - -#if 1 - #if 0 - tree addr = build2(ADDR_EXPR, map_type, map_ptr, area_off); - g = gimple_build_assign(map_ptr2, MODIFY_EXPR, addr); - gimple_seq_add_stmt(&seq, g); // map_ptr2 = map_ptr + area_off - update_stmt(g); - #else - g = gimple_build_assign(map_ptr2, PLUS_EXPR, map_ptr, area_off); - gimple_seq_add_stmt(&seq, g); // map_ptr2 = map_ptr + area_off - update_stmt(g); - #endif - - // gimple_assign <mem_ref, _3, *p_6, NULL, NULL> - tree tmp1 = create_tmp_var_raw(unsigned_char_type_node, "tmp1"); - g = gimple_build_assign(tmp1, MEM_REF, map_ptr2); - gimple_seq_add_stmt(&seq, g); // tmp1 = *map_ptr2 - update_stmt(g); -#else - tree atIndex = build2(PLUS_EXPR, uint32_type_node, map_ptr, area_off); - tree array_address = build1(ADDR_EXPR, map_type, atIndex); - tree array_access = build1(INDIRECT_REF, map_type, array_address); - tree tmp1 = create_tmp_var(unsigned_char_type_node, "tmp1"); - g = gimple_build_assign(tmp1, array_access); - gimple_seq_add_stmt(&seq, g); // tmp1 = *(map_ptr + area_off) - update_stmt(g); -#endif - // gimple_assign <plus_expr, _4, _3, 1, NULL> - tree tmp2 = create_tmp_var_raw(unsigned_char_type_node, "tmp2"); - g = gimple_build_assign(tmp2, PLUS_EXPR, tmp1, one); - gimple_seq_add_stmt(&seq, g); // tmp2 = tmp1 + 1 - update_stmt(g); - - // TODO: neverZero: here we have to check if tmp3 == 0 - // and add 1 if so - - // gimple_assign <ssa_name, *p_6, _4, NULL, NULL> - // tree map_ptr3 = create_tmp_var_raw(map_type, "map_ptr3"); - g = gimple_build_assign(map_ptr2, INDIRECT_REF, tmp2); - gimple_seq_add_stmt(&seq, g); // *map_ptr2 = tmp2 - update_stmt(g); - - /* Set prev_loc to cur_loc >> 1 */ - - // gimple_assign <integer_cst, prev_loc, 23615, NULL, NULL> - tree shifted_loc = build_int_cst(TREE_TYPE(prev_loc_g), rand_loc >> 1); - tree prev_loc2 = create_tmp_var_raw(uint32_type_node, "prev_loc2"); - g = gimple_build_assign(prev_loc2, shifted_loc); - gimple_seq_add_stmt(&seq, g); // __afl_prev_loc = cur_loc >> 1 - update_stmt(g); - g = gimple_build_assign(prev_loc_g, prev_loc2); - gimple_seq_add_stmt(&seq, g); // __afl_prev_loc = cur_loc >> 1 - update_stmt(g); - - /* Done - grab the entry to the block and insert sequence */ - - bentry = gsi_after_labels(bb); - gsi_insert_seq_before(&bentry, seq, GSI_NEW_STMT); - - ++finst_blocks; - - } - - /* Say something nice. */ - if (!be_quiet) { - - if (!finst_blocks) - WARNF(G_("No instrumentation targets found in " cBRI "%s" cRST), - function_name(fun)); - else if (finst_blocks < fcnt_blocks) - OKF(G_("Instrumented %2u /%2u locations in " cBRI "%s" cRST), - finst_blocks, fcnt_blocks, function_name(fun)); - else - OKF(G_("Instrumented %2u locations in " cBRI "%s" cRST), finst_blocks, - function_name(fun)); - - } - - return 0; - -} - -/* -------------------------------------------------------------------------- */ -/* -- Boilerplate and initialization ---------------------------------------- */ - -static const struct pass_data afl_pass_data = { - - .type = GIMPLE_PASS, - .name = "afl-inst", - .optinfo_flags = OPTGROUP_NONE, - - .tv_id = TV_NONE, - .properties_required = 0, - .properties_provided = 0, - .properties_destroyed = 0, - .todo_flags_start = 0, - // NOTE(aseipp): it's very, very important to include - // at least 'TODO_update_ssa' here so that GCC will - // properly update the resulting SSA form, e.g., to - // include new PHI nodes for newly added symbols or - // names. Do not remove this. Do not taunt Happy Fun - // Ball. - .todo_flags_finish = TODO_update_ssa | TODO_verify_il | TODO_cleanup_cfg, - -}; - -namespace { - -class afl_pass : public gimple_opt_pass { - - private: - bool do_ext_call; - - public: - afl_pass(bool ext_call, gcc::context *g) - : gimple_opt_pass(afl_pass_data, g), do_ext_call(ext_call) { - - } - - unsigned int execute(function *fun) override { - - if (!myInstrumentList.empty()) { - - bool instrumentBlock = false; - std::string instFilename; - unsigned int instLine = 0; - - /* EXPR_FILENAME - This macro returns the name of the file in which the entity was declared, - as a char*. For an entity declared implicitly by the compiler (like - __builtin_ memcpy), this will be the string "<internal>". - */ - const char *fname = DECL_SOURCE_FILE(fun->decl); - - if (0 != strncmp("<internal>", fname, 10) && - 0 != strncmp("<built-in>", fname, 10)) { - - instFilename = fname; - instLine = DECL_SOURCE_LINE(fun->decl); - - /* Continue only if we know where we actually are */ - if (!instFilename.empty()) { - - for (std::list<std::string>::iterator it = myInstrumentList.begin(); - it != myInstrumentList.end(); ++it) { - - /* We don't check for filename equality here because - * filenames might actually be full paths. Instead we - * check that the actual filename ends in the filename - * specified in the list. */ - if (instFilename.length() >= it->length()) { - - if (instFilename.compare(instFilename.length() - it->length(), - it->length(), *it) == 0) { - - instrumentBlock = true; - break; - - } - - } - - } - - } - - } - - /* Either we couldn't figure out our location or the location is - * not in the instrument list, so we skip instrumentation. */ - if (!instrumentBlock) { - - if (!be_quiet) { - - if (!instFilename.empty()) - SAYF(cYEL "[!] " cBRI - "Not in instrument list, skipping %s line %u...\n", - instFilename.c_str(), instLine); - else - SAYF(cYEL "[!] " cBRI "No filename information found, skipping it"); - - } - - return 0; - - } - - } - - return do_ext_call ? ext_call_instrument(fun) : inline_instrument(fun); - - } - -}; /* class afl_pass */ - -} // namespace - -static struct opt_pass *make_afl_pass(bool ext_call, gcc::context *ctxt) { - - return new afl_pass(ext_call, ctxt); - -} - -/* -------------------------------------------------------------------------- */ -/* -- Initialization -------------------------------------------------------- */ - -int plugin_is_GPL_compatible = 1; - -static struct plugin_info afl_plugin_info = { - - .version = "20200519", - .help = "AFL++ gcc plugin\n", - -}; - -int plugin_init(struct plugin_name_args * plugin_info, - struct plugin_gcc_version *version) { - - struct register_pass_info afl_pass_info; - struct timeval tv; - struct timezone tz; - u32 rand_seed; - - /* Setup random() so we get Actually Random(TM) outputs from R() */ - gettimeofday(&tv, &tz); - rand_seed = tv.tv_sec ^ tv.tv_usec ^ getpid(); - SR(rand_seed); - - /* Pass information */ - afl_pass_info.pass = make_afl_pass(inst_ext, g); - afl_pass_info.reference_pass_name = "ssa"; - afl_pass_info.ref_pass_instance_number = 1; - afl_pass_info.pos_op = PASS_POS_INSERT_AFTER; - - if (!plugin_default_version_check(version, &gcc_version)) { - - FATAL(G_("Incompatible gcc/plugin versions! Expected GCC %d.%d"), - GCCPLUGIN_VERSION_MAJOR, GCCPLUGIN_VERSION_MINOR); - - } - - /* Show a banner */ - if ((isatty(2) && !getenv("AFL_QUIET")) || getenv("AFL_DEBUG") != NULL) { - - SAYF(G_(cCYA "afl-gcc-pass" VERSION cRST - " initially by <aseipp@pobox.com>, maintainer: hexcoder-\n")); - - } else - - be_quiet = 1; - - /* Decide instrumentation ratio */ - char *inst_ratio_str = getenv("AFL_INST_RATIO"); - - if (inst_ratio_str) { - - if (sscanf(inst_ratio_str, "%u", &inst_ratio) != 1 || !inst_ratio || - inst_ratio > 100) - FATAL(G_("Bad value of AFL_INST_RATIO (must be between 1 and 100)")); - else { - - if (!be_quiet) - ACTF(G_("%s instrumentation at ratio of %u%% in %s mode."), - inst_ext ? G_("Call-based") : G_("Inline"), inst_ratio, - getenv("AFL_HARDEN") ? G_("hardened") : G_("non-hardened")); - - } - - } - - char *instInstrumentListFilename = getenv("AFL_GCC_INSTRUMENT_FILE"); - if (!instInstrumentListFilename) - instInstrumentListFilename = getenv("AFL_GCC_WHITELIST"); - if (instInstrumentListFilename) { - - std::string line; - std::ifstream fileStream; - fileStream.open(instInstrumentListFilename); - if (!fileStream) PFATAL("Unable to open AFL_GCC_INSTRUMENT_FILE"); - getline(fileStream, line); - while (fileStream) { - - myInstrumentList.push_back(line); - getline(fileStream, line); - - } - - } else if (!be_quiet && (getenv("AFL_LLVM_WHITELIST") || - - getenv("AFL_LLVM_INSTRUMENT_FILE"))) { - - SAYF(cYEL "[-] " cRST - "AFL_LLVM_INSTRUMENT_FILE environment variable detected - did " - "you mean AFL_GCC_INSTRUMENT_FILE?\n"); - - } - - /* Go go gadget */ - register_callback(plugin_info->base_name, PLUGIN_INFO, NULL, - &afl_plugin_info); - register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, - &afl_pass_info); - return 0; - -} - |