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afl-tmin.c
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/*
american fuzzy lop - test case minimizer
----------------------------------------
Written and maintained by Michal Zalewski <[email protected]>
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
http://www.apache.org/licenses/LICENSE-2.0
A simple test case minimizer that takes an input file and tries to remove
as much data as possible while keeping the binary in a crashing state
*or* producing consistent instrumentation output (the mode is auto-selected
based on the initially observed behavior).
*/
#define AFL_MAIN
#include "config.h"
#include "types.h"
#include "debug.h"
#include "alloc-inl.h"
#include "hash.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <signal.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/resource.h>
static s32 forksrv_pid, /* PID of the fork server */
child_pid; /* PID of the tested program */
static s32 fsrv_ctl_fd, /* Fork server control pipe (write) */
fsrv_st_fd; /* Fork server status pipe (read) */
static u8 *trace_bits, /* SHM with instrumentation bitmap */
*mask_bitmap; /* Mask for trace bits (-B) */
static u8 *in_file, /* Minimizer input test case */
*out_file, /* Minimizer output file */
*prog_in, /* Targeted program input file */
*target_path, /* Path to target binary */
*doc_path; /* Path to docs */
static u8* in_data; /* Input data for trimming */
static u32 in_len, /* Input data length */
orig_cksum, /* Original checksum */
total_execs, /* Total number of execs */
missed_hangs, /* Misses due to hangs */
missed_crashes, /* Misses due to crashes */
missed_paths, /* Misses due to exec path diffs */
exec_tmout = EXEC_TIMEOUT; /* Exec timeout (ms) */
static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */
static s32 shm_id, /* ID of the SHM region */
dev_null_fd = -1, /* FD to /dev/null */
prog_in_fd; /* Persistent fd for out_file */
static u8 crash_mode, /* Crash-centric mode? */
exit_crash, /* Treat non-zero exit as crash? */
edges_only, /* Ignore hit counts? */
exact_mode, /* Require path match for crashes? */
use_stdin = 1; /* Use stdin for program input? */
static volatile u8
stop_soon, /* Ctrl-C pressed? */
child_timed_out; /* Child timed out? */
/* Classify tuple counts. This is a slow & naive version, but good enough here. */
static const u8 count_class_lookup[256] = {
[0] = 0,
[1] = 1,
[2] = 2,
[3] = 4,
[4 ... 7] = 8,
[8 ... 15] = 16,
[16 ... 31] = 32,
[32 ... 127] = 64,
[128 ... 255] = 128
};
static void classify_counts(u8* mem) {
u32 i = MAP_SIZE;
if (edges_only) {
while (i--) {
if (*mem) *mem = 1;
mem++;
}
} else {
while (i--) {
*mem = count_class_lookup[*mem];
mem++;
}
}
}
/* Apply mask to classified bitmap (if set). */
static void apply_mask(u32* mem, u32* mask) {
u32 i = (MAP_SIZE >> 2);
if (!mask) return;
while (i--) {
*mem &= ~*mask;
mem++;
mask++;
}
}
/* See if any bytes are set in the bitmap. */
static inline u8 anything_set(void) {
u32* ptr = (u32*)trace_bits;
u32 i = (MAP_SIZE >> 2);
while (i--) if (*(ptr++)) return 1;
return 0;
}
/* Describe integer. Uses 12 cyclic static buffers for return values. The value
returned should be five characters or less for all the integers we reasonably
expect to see. */
static u8* DI(u64 val) {
static u8 tmp[12][16];
static u8 cur;
cur = (cur + 1) % 12;
#define CHK_FORMAT(_divisor, _limit_mult, _fmt, _cast) do { \
if (val < (_divisor) * (_limit_mult)) { \
sprintf(tmp[cur], _fmt, ((_cast)val) / (_divisor)); \
return tmp[cur]; \
} \
} while (0)
/* 0-9999 */
CHK_FORMAT(1, 10000, "%llu", u64);
/* 10.0k - 99.9k */
CHK_FORMAT(1000, 99.95, "%0.01fk", double);
/* 100k - 999k */
CHK_FORMAT(1000, 1000, "%lluk", u64);
/* 1.00M - 9.99M */
CHK_FORMAT(1000 * 1000, 9.995, "%0.02fM", double);
/* 10.0M - 99.9M */
CHK_FORMAT(1000 * 1000, 99.95, "%0.01fM", double);
/* 100M - 999M */
CHK_FORMAT(1000 * 1000, 1000, "%lluM", u64);
/* 1.00G - 9.99G */
CHK_FORMAT(1000LL * 1000 * 1000, 9.995, "%0.02fG", double);
/* 10.0G - 99.9G */
CHK_FORMAT(1000LL * 1000 * 1000, 99.95, "%0.01fG", double);
/* 100G - 999G */
CHK_FORMAT(1000LL * 1000 * 1000, 1000, "%lluG", u64);
/* 1.00T - 9.99G */
CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 9.995, "%0.02fT", double);
/* 10.0T - 99.9T */
CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 99.95, "%0.01fT", double);
/* 100T+ */
strcpy(tmp[cur], "infty");
return tmp[cur];
}
/* Describe float. Similar to the above, except with a single
static buffer. */
static u8* DF(double val) {
static u8 tmp[16];
if (val < 99.995) {
sprintf(tmp, "%0.02f", val);
return tmp;
}
if (val < 999.95) {
sprintf(tmp, "%0.01f", val);
return tmp;
}
return DI((u64)val);
}
/* Describe integer as memory size. */
static u8* DMS(u64 val) {
static u8 tmp[12][16];
static u8 cur;
cur = (cur + 1) % 12;
/* 0-9999 */
CHK_FORMAT(1, 10000, "%llu B", u64);
/* 10.0k - 99.9k */
CHK_FORMAT(1024, 99.95, "%0.01f kB", double);
/* 100k - 999k */
CHK_FORMAT(1024, 1000, "%llu kB", u64);
/* 1.00M - 9.99M */
CHK_FORMAT(1024 * 1024, 9.995, "%0.02f MB", double);
/* 10.0M - 99.9M */
CHK_FORMAT(1024 * 1024, 99.95, "%0.01f MB", double);
/* 100M - 999M */
CHK_FORMAT(1024 * 1024, 1000, "%llu MB", u64);
/* 1.00G - 9.99G */
CHK_FORMAT(1024LL * 1024 * 1024, 9.995, "%0.02f GB", double);
/* 10.0G - 99.9G */
CHK_FORMAT(1024LL * 1024 * 1024, 99.95, "%0.01f GB", double);
/* 100G - 999G */
CHK_FORMAT(1024LL * 1024 * 1024, 1000, "%llu GB", u64);
/* 1.00T - 9.99G */
CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 9.995, "%0.02f TB", double);
/* 10.0T - 99.9T */
CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 99.95, "%0.01f TB", double);
#undef CHK_FORMAT
/* 100T+ */
strcpy(tmp[cur], "infty");
return tmp[cur];
}
/* Describe time delta. Returns one static buffer, 34 chars of less. */
static u8* DTD(u64 cur_ms, u64 event_ms) {
static u8 tmp[64];
u64 delta;
s32 t_d, t_h, t_m, t_s;
if (!event_ms) return "none seen yet";
delta = cur_ms - event_ms;
t_d = delta / 1000 / 60 / 60 / 24;
t_h = (delta / 1000 / 60 / 60) % 24;
t_m = (delta / 1000 / 60) % 60;
t_s = (delta / 1000) % 60;
sprintf(tmp, "%s days, %u hrs, %u min, %u sec", DI(t_d), t_h, t_m, t_s);
return tmp;
}
/* Get rid of shared memory and temp files (atexit handler). */
static void remove_shm(void) {
if (prog_in) unlink(prog_in); /* Ignore errors */
shmctl(shm_id, IPC_RMID, NULL);
}
/* Configure shared memory. */
static void setup_shm(void) {
u8* shm_str;
shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600);
if (shm_id < 0) PFATAL("shmget() failed");
atexit(remove_shm);
shm_str = alloc_printf("%d", shm_id);
setenv(SHM_ENV_VAR, shm_str, 1);
ck_free(shm_str);
trace_bits = shmat(shm_id, NULL, 0);
if (!trace_bits) PFATAL("shmat() failed");
}
/* Read initial file. */
static void read_initial_file(void) {
struct stat st;
s32 fd = open(in_file, O_RDONLY);
if (fd < 0) PFATAL("Unable to open '%s'", in_file);
if (fstat(fd, &st) || !st.st_size)
FATAL("Zero-sized input file.");
if (st.st_size >= TMIN_MAX_FILE)
FATAL("Input file is too large (%u MB max)", TMIN_MAX_FILE / 1024 / 1024);
in_len = st.st_size;
in_data = ck_alloc_nozero(in_len);
ck_read(fd, in_data, in_len, in_file);
close(fd);
OKF("Read %u byte%s from '%s'.", in_len, in_len == 1 ? "" : "s", in_file);
}
/* Write output file. */
static s32 write_to_file(u8* path, u8* mem, u32 len) {
s32 ret;
unlink(path); /* Ignore errors */
ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600);
if (ret < 0) PFATAL("Unable to create '%s'", path);
ck_write(ret, mem, len, path);
lseek(ret, 0, SEEK_SET);
return ret;
}
/* Write modified data to file for testing. If use_stdin is not set, the old file
is unlinked and a new one is created. Otherwise, prog_in_fd is rewound and
truncated. */
static void write_to_testcase(void* mem, u32 len) {
s32 fd = prog_in_fd;
if (!use_stdin) {
unlink(prog_in); /* Ignore errors. */
fd = open(prog_in, O_WRONLY | O_CREAT | O_EXCL, 0600);
if (fd < 0) PFATAL("Unable to create '%s'", prog_in);
} else lseek(fd, 0, SEEK_SET);
ck_write(fd, mem, len, prog_in);
if (use_stdin) {
if (ftruncate(fd, len)) PFATAL("ftruncate() failed");
lseek(fd, 0, SEEK_SET);
} else close(fd);
}
/* Handle timeout signal. */
static void handle_timeout(int sig) {
child_timed_out = 1;
if (child_pid > 0) kill(child_pid, SIGKILL);
}
/* Spin up fork server (instrumented mode only). The idea is explained here:
http://lcamtuf.blogspot.com/2014/10/fuzzing-binaries-without-execve.html
In essence, the instrumentation allows us to skip execve(), and just keep
cloning a stopped child. So, we just execute once, and then send commands
through a pipe. The other part of this logic is in afl-as.h. */
static void init_forkserver(char** argv) {
static struct itimerval it;
int st_pipe[2], ctl_pipe[2];
int status;
s32 rlen;
ACTF("Spinning up the fork server...");
if (pipe(st_pipe) || pipe(ctl_pipe)) PFATAL("pipe() failed");
forksrv_pid = fork();
if (forksrv_pid < 0) PFATAL("fork() failed");
if (!forksrv_pid) {
struct rlimit r;
/* Umpf. On OpenBSD, the default fd limit for root users is set to
soft 128. Let's try to fix that... */
if (!getrlimit(RLIMIT_NOFILE, &r) && r.rlim_cur < FORKSRV_FD + 2) {
r.rlim_cur = FORKSRV_FD + 2;
setrlimit(RLIMIT_NOFILE, &r); /* Ignore errors */
}
if (mem_limit) {
r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20;
#ifdef RLIMIT_AS
setrlimit(RLIMIT_AS, &r); /* Ignore errors */
#else
/* This takes care of OpenBSD, which doesn't have RLIMIT_AS, but
according to reliable sources, RLIMIT_DATA covers anonymous
maps - so we should be getting good protection against OOM bugs. */
setrlimit(RLIMIT_DATA, &r); /* Ignore errors */
#endif /* ^RLIMIT_AS */
}
/* Dumping cores is slow and can lead to anomalies if SIGKILL is delivered
before the dump is complete. */
r.rlim_max = r.rlim_cur = 0;
setrlimit(RLIMIT_CORE, &r); /* Ignore errors */
/* Isolate the process and configure standard descriptors. If out_file is
specified, stdin is /dev/null; otherwise, out_fd is cloned instead. */
setsid();
dup2(dev_null_fd, 1);
dup2(dev_null_fd, 2);
if (out_file) {
dup2(dev_null_fd, 0);
} else {
dup2(prog_in_fd, 0);
close(prog_in_fd);
}
/* Set up control and status pipes, close the unneeded original fds. */
if (dup2(ctl_pipe[0], FORKSRV_FD) < 0) PFATAL("dup2() failed");
if (dup2(st_pipe[1], FORKSRV_FD + 1) < 0) PFATAL("dup2() failed");
close(ctl_pipe[0]);
close(ctl_pipe[1]);
close(st_pipe[0]);
close(st_pipe[1]);
close(dev_null_fd);
/* This should improve performance a bit, since it stops the linker from
doing extra work post-fork(). */
if (!getenv("LD_BIND_LAZY")) setenv("LD_BIND_NOW", "1", 0);
/* Set sane defaults for ASAN if nothing else specified. */
setenv("ASAN_OPTIONS", "abort_on_error=1:"
"detect_leaks=0:"
"symbolize=0:"
"allocator_may_return_null=1", 0);
/* MSAN is tricky, because it doesn't support abort_on_error=1 at this
point. So, we do this in a very hacky way. */
setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":"
"symbolize=0:"
"abort_on_error=1:"
"allocator_may_return_null=1:"
"msan_track_origins=0", 0);
execv(target_path, argv);
/* Use a distinctive bitmap signature to tell the parent about execv()
falling through. */
*(u32*)trace_bits = EXEC_FAIL_SIG;
exit(0);
}
/* Close the unneeded endpoints. */
close(ctl_pipe[0]);
close(st_pipe[1]);
fsrv_ctl_fd = ctl_pipe[1];
fsrv_st_fd = st_pipe[0];
/* Wait for the fork server to come up, but don't wait too long. */
it.it_value.tv_sec = ((exec_tmout * FORK_WAIT_MULT) / 1000);
it.it_value.tv_usec = ((exec_tmout * FORK_WAIT_MULT) % 1000) * 1000;
setitimer(ITIMER_REAL, &it, NULL);
rlen = read(fsrv_st_fd, &status, 4);
it.it_value.tv_sec = 0;
it.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &it, NULL);
/* If we have a four-byte "hello" message from the server, we're all set.
Otherwise, try to figure out what went wrong. */
if (rlen == 4) {
OKF("All right - fork server is up.");
return;
}
if (child_timed_out)
FATAL("Timeout while initializing fork server (adjusting -t may help)");
if (waitpid(forksrv_pid, &status, 0) <= 0)
PFATAL("waitpid() failed");
if (WIFSIGNALED(status)) {
/*if (mem_limit && mem_limit < 500 && uses_asan) {
SAYF("\n" cLRD "[-] " cRST
"Whoops, the target binary crashed suddenly, before receiving any input\n"
" from the fuzzer! Since it seems to be built with ASAN and you have a\n"
" restrictive memory limit configured, this is expected; please read\n"
" %s/notes_for_asan.txt for help.\n", doc_path);
} else */if (!mem_limit) {
SAYF("\n" cLRD "[-] " cRST
"Whoops, the target binary crashed suddenly, before receiving any input\n"
" from the fuzzer! There are several probable explanations:\n\n"
" - The binary is just buggy and explodes entirely on its own. If so, you\n"
" need to fix the underlying problem or find a better replacement.\n\n"
#ifdef __APPLE__
" - On MacOS X, the semantics of fork() syscalls are non-standard and may\n"
" break afl-fuzz performance optimizations when running platform-specific\n"
" targets. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n"
#endif /* __APPLE__ */
" - Less likely, there is a horrible bug in the fuzzer. If other options\n"
" fail, poke <[email protected]> for troubleshooting tips.\n");
} else {
SAYF("\n" cLRD "[-] " cRST
"Whoops, the target binary crashed suddenly, before receiving any input\n"
" from the fuzzer! There are several probable explanations:\n\n"
" - The current memory limit (%s) is too restrictive, causing the\n"
" target to hit an OOM condition in the dynamic linker. Try bumping up\n"
" the limit with the -m setting in the command line. A simple way confirm\n"
" this diagnosis would be:\n\n"
#ifdef RLIMIT_AS
" ( ulimit -Sv $[%llu << 10]; /path/to/fuzzed_app )\n\n"
#else
" ( ulimit -Sd $[%llu << 10]; /path/to/fuzzed_app )\n\n"
#endif /* ^RLIMIT_AS */
" Tip: you can use http://jwilk.net/software/recidivm to quickly\n"
" estimate the required amount of virtual memory for the binary.\n\n"
" - The binary is just buggy and explodes entirely on its own. If so, you\n"
" need to fix the underlying problem or find a better replacement.\n\n"
#ifdef __APPLE__
" - On MacOS X, the semantics of fork() syscalls are non-standard and may\n"
" break afl-fuzz performance optimizations when running platform-specific\n"
" targets. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n"
#endif /* __APPLE__ */
" - Less likely, there is a horrible bug in the fuzzer. If other options\n"
" fail, poke <[email protected]> for troubleshooting tips.\n",
DMS(mem_limit << 20), mem_limit - 1);
}
FATAL("Fork server crashed with signal %d", WTERMSIG(status));
}
if (*(u32*)trace_bits == EXEC_FAIL_SIG)
FATAL("Unable to execute target application ('%s')", argv[0]);
/*if (mem_limit && mem_limit < 500 && uses_asan) {
SAYF("\n" cLRD "[-] " cRST
"Hmm, looks like the target binary terminated before we could complete a\n"
" handshake with the injected code. Since it seems to be built with ASAN and\n"
" you have a restrictive memory limit configured, this is expected; please\n"
" read %s/notes_for_asan.txt for help.\n", doc_path);
} else */if (!mem_limit) {
SAYF("\n" cLRD "[-] " cRST
"Hmm, looks like the target binary terminated before we could complete a\n"
" handshake with the injected code. Perhaps there is a horrible bug in the\n"
" fuzzer. Poke <[email protected]> for troubleshooting tips.\n");
} else {
SAYF("\n" cLRD "[-] " cRST
"Hmm, looks like the target binary terminated before we could complete a\n"
" handshake with the injected code. There are %s probable explanations:\n\n"
"%s"
" - The current memory limit (%s) is too restrictive, causing an OOM\n"
" fault in the dynamic linker. This can be fixed with the -m option. A\n"
" simple way to confirm the diagnosis may be:\n\n"
#ifdef RLIMIT_AS
" ( ulimit -Sv $[%llu << 10]; /path/to/fuzzed_app )\n\n"
#else
" ( ulimit -Sd $[%llu << 10]; /path/to/fuzzed_app )\n\n"
#endif /* ^RLIMIT_AS */
" Tip: you can use http://jwilk.net/software/recidivm to quickly\n"
" estimate the required amount of virtual memory for the binary.\n\n"
" - Less likely, there is a horrible bug in the fuzzer. If other options\n"
" fail, poke <[email protected]> for troubleshooting tips.\n",
getenv(DEFER_ENV_VAR) ? "three" : "two",
getenv(DEFER_ENV_VAR) ?
" - You are using deferred forkserver, but __AFL_INIT() is never\n"
" reached before the program terminates.\n\n" : "",
DMS(mem_limit << 20), mem_limit - 1);
}
FATAL("Fork server handshake failed");
}
/* Execute target application. Returns 0 if the changes are a dud, or
1 if they should be kept. */
static u8 run_target(char** argv, u8* mem, u32 len, u8 first_run) {
static struct itimerval it;
static u32 prev_timed_out = 0;
int status = 0;
u32 cksum;
memset(trace_bits, 0, MAP_SIZE);
MEM_BARRIER();
write_to_testcase(mem, len);
s32 res;
/* In non-dumb mode, we have the fork server up and running, so simply
tell it to have at it, and then read back PID. */
if ((res = write(fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
if (stop_soon) return 0;
RPFATAL(res, "Unable to request new process from fork server (OOM?)");
}
if ((res = read(fsrv_st_fd, &child_pid, 4)) != 4) {
if (stop_soon) return 0;
RPFATAL(res, "Unable to request new process from fork server (OOM?)");
}
if (child_pid <= 0) FATAL("Fork server is misbehaving (OOM?)");
/* Configure timeout, wait for child, cancel timeout. */
child_timed_out = 0;
it.it_value.tv_sec = (exec_tmout / 1000);
it.it_value.tv_usec = (exec_tmout % 1000) * 1000;
setitimer(ITIMER_REAL, &it, NULL);
if ((res = read(fsrv_st_fd, &status, 4)) != 4) {
if (stop_soon) return 0;
RPFATAL(res, "Unable to communicate with fork server (OOM?)");
}
child_pid = 0;
it.it_value.tv_sec = 0;
it.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &it, NULL);
MEM_BARRIER();
/* Clean up bitmap, analyze exit condition, etc. */
if (*(u32*)trace_bits == EXEC_FAIL_SIG)
FATAL("Unable to execute '%s'", argv[0]);
classify_counts(trace_bits);
apply_mask((u32*)trace_bits, (u32*)mask_bitmap);
total_execs++;
if (stop_soon) {
SAYF(cRST cLRD "\n+++ Minimization aborted by user +++\n" cRST);
close(write_to_file(out_file, in_data, in_len));
exit(1);
}
/* Always discard inputs that time out. */
if (child_timed_out) {
missed_hangs++;
return 0;
}
/* Handle crashing inputs depending on current mode. */
if (WIFSIGNALED(status) ||
(WIFEXITED(status) && WEXITSTATUS(status) == MSAN_ERROR) ||
(WIFEXITED(status) && WEXITSTATUS(status) && exit_crash)) {
if (first_run) crash_mode = 1;
if (crash_mode) {
if (!exact_mode) return 1;
} else {
missed_crashes++;
return 0;
}
}
/* Handle non-crashing inputs appropriately. */
if (crash_mode) {
missed_paths++;
return 0;
}
cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST);
if (first_run) orig_cksum = cksum;
if (orig_cksum == cksum) return 1;
missed_paths++;
return 0;
}
/* Find first power of two greater or equal to val. */
static u32 next_p2(u32 val) {
u32 ret = 1;
while (val > ret) ret <<= 1;
return ret;
}
/* Actually minimize! */
static void minimize(char** argv) {
static u32 alpha_map[256];
u8* tmp_buf = ck_alloc_nozero(in_len);
u32 orig_len = in_len, stage_o_len;
u32 del_len, set_len, del_pos, set_pos, i, alpha_size, cur_pass = 0;
u32 syms_removed, alpha_del0 = 0, alpha_del1, alpha_del2, alpha_d_total = 0, bits_zeroed, total_bits_zeroed = 0;
u8 changed_any, prev_del;
s32 j;
/***********************
* BLOCK NORMALIZATION *
***********************/
set_len = next_p2(in_len / TMIN_SET_STEPS);
set_pos = 0;
if (set_len < TMIN_SET_MIN_SIZE) set_len = TMIN_SET_MIN_SIZE;
ACTF(cBRI "Stage #0: " cRST "One-time block normalization...");
while (set_pos < in_len) {
u8 res;
u32 use_len = MIN(set_len, in_len - set_pos);
for (i = 0; i < use_len; i++)
if (in_data[set_pos + i] != '\x00') break;
if (i != use_len) {
memcpy(tmp_buf, in_data, in_len);
memset(tmp_buf + set_pos, '\x00', use_len);
res = run_target(argv, tmp_buf, in_len, 0);
if (res) {
memset(in_data + set_pos, '\x00', use_len);
changed_any = 1;
alpha_del0 += use_len;
}
}
set_pos += set_len;
}
alpha_d_total += alpha_del0;
OKF("Block normalization complete, %u byte%s replaced.", alpha_del0,
alpha_del0 == 1 ? "" : "s");
next_pass:
ACTF(cYEL "--- " cBRI "Pass #%u " cYEL "---", ++cur_pass);
changed_any = 0;
// Tobi: Could remove block deletion step if it does not work well with flat MMIO accesses
#if 1
/******************
* BLOCK DELETION *
******************/
del_len = next_p2(in_len / TRIM_START_STEPS);
stage_o_len = in_len;
ACTF(cBRI "Stage #1: " cRST "Removing blocks of data...");
next_del_blksize:
if (!del_len) del_len = 1;
del_pos = 0;
prev_del = 1;
SAYF(cGRA " Block length = %u, remaining size = %u\n" cRST,
del_len, in_len);
while (del_pos < in_len) {
u8 res;
s32 tail_len;
tail_len = in_len - del_pos - del_len;
if (tail_len < 0) tail_len = 0;
/* If we have processed at least one full block (initially, prev_del == 1),
and we did so without deleting the previous one, and we aren't at the
very end of the buffer (tail_len > 0), and the current block is the same
as the previous one... skip this step as a no-op. */
if (!prev_del && tail_len && !memcmp(in_data + del_pos - del_len,
in_data + del_pos, del_len)) {
del_pos += del_len;
continue;
}
prev_del = 0;
/* Head */
memcpy(tmp_buf, in_data, del_pos);
/* Tail */
memcpy(tmp_buf + del_pos, in_data + del_pos + del_len, tail_len);
res = run_target(argv, tmp_buf, del_pos + tail_len, 0);
if (res) {
memcpy(in_data, tmp_buf, del_pos + tail_len);
prev_del = 1;
in_len = del_pos + tail_len;
changed_any = 1;
} else del_pos += del_len;
}
if (del_len > 4 && in_len >= 1) {
del_len /= 2;
goto next_del_blksize;
}
OKF("Block removal complete, %u bytes deleted.", stage_o_len - in_len);
if (!in_len && changed_any)
WARNF(cLRD "Down to zero bytes - check the command line and mem limit!" cRST);
if (cur_pass > 1 && !changed_any) goto bit_minimization;