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cpu-exec.c
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cpu-exec.c
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/*
* emulator main execution loop
*
* Copyright (c) 2003-2005 Fabrice Bellard
*
* This 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.
*
* This 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 this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/qemu-print.h"
#include "cpu.h"
#include "hw/core/tcg-cpu-ops.h"
#include "trace.h"
#include "disas/disas.h"
#include "exec/exec-all.h"
#include "tcg/tcg.h"
#include "qemu/atomic.h"
#include "qemu/compiler.h"
#include "sysemu/qtest.h"
#include "qemu/timer.h"
#include "qemu/rcu.h"
#include "exec/tb-hash.h"
#include "exec/tb-lookup.h"
#include "exec/log.h"
#include "qemu/main-loop.h"
#include "qemu/selfmap.h"
#if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
#include "hw/i386/apic.h"
#endif
#include "sysemu/cpus.h"
#include "exec/cpu-all.h"
#include "sysemu/cpu-timers.h"
#include "sysemu/replay.h"
#include "internal.h"
#include "qemuafl/common.h"
#include "qemuafl/imported/snapshot-inl.h"
#include <string.h>
#include <sys/shm.h>
#ifndef AFL_QEMU_STATIC_BUILD
#include <dlfcn.h>
#endif
/***************************
* VARIOUS AUXILIARY STUFF *
***************************/
/* This is equivalent to afl-as.h: */
static unsigned char
dummy[MAP_SIZE]; /* costs MAP_SIZE but saves a few instructions */
unsigned char *afl_area_ptr = dummy; /* Exported for afl_gen_trace */
/* Exported variables populated by the code patched into elfload.c: */
abi_ulong afl_entry_point, /* ELF entry point (_start) */
afl_start_code, /* .text start pointer */
afl_end_code; /* .text end pointer */
struct vmrange* afl_instr_code;
abi_ulong afl_persistent_addr, afl_persistent_ret_addr;
unsigned int afl_persistent_cnt;
u8 afl_compcov_level;
__thread abi_ulong afl_prev_loc;
struct cmp_map *__afl_cmp_map;
/* Set in the child process in forkserver mode: */
static int forkserver_installed = 0;
static int disable_caching = 0;
unsigned char afl_fork_child;
unsigned int afl_forksrv_pid;
unsigned char is_persistent;
target_long persistent_stack_offset;
unsigned char persistent_first_pass = 1;
unsigned char persistent_exits;
unsigned char persistent_save_gpr;
unsigned char persistent_memory;
int persisent_retaddr_offset;
struct api_regs saved_regs;
u8 * shared_buf;
u32 *shared_buf_len;
u8 sharedmem_fuzzing;
afl_persistent_hook_fn afl_persistent_hook_ptr;
/* Instrumentation ratio: */
unsigned int afl_inst_rms = MAP_SIZE; /* Exported for afl_gen_trace */
/* Function declarations. */
static void afl_wait_tsl(CPUState *, int);
static void afl_request_tsl(target_ulong, target_ulong, uint32_t, uint32_t,
TranslationBlock *, int);
/* Data structures passed around by the translate handlers: */
struct afl_tb {
target_ulong pc;
target_ulong cs_base;
uint32_t flags;
uint32_t cf_mask;
};
struct afl_chain {
struct afl_tb last_tb;
uint32_t cf_mask;
int tb_exit;
};
struct afl_tsl {
struct afl_tb tb;
struct afl_chain chain;
char is_chain;
};
/* Some forward decls: */
static inline TranslationBlock *tb_find(CPUState *, TranslationBlock *, int,
uint32_t);
static inline void tb_add_jump(TranslationBlock *tb, int n,
TranslationBlock *tb_next);
static void afl_map_shm_fuzz(void);
/*************************
* ACTUAL IMPLEMENTATION *
*************************/
/* Snapshot memory */
struct saved_region {
void* addr;
size_t size;
void* saved;
};
abi_ulong saved_brk;
int lkm_snapshot;
struct saved_region* memory_snapshot;
size_t memory_snapshot_len;
static void collect_memory_snapshot(void) {
saved_brk = afl_get_brk();
FILE *fp;
char *line = NULL;
size_t len = 0;
ssize_t read;
fp = fopen("/proc/self/maps", "r");
if (fp == NULL) {
fprintf(stderr, "[AFL] ERROR: cannot open /proc/self/maps\n");
exit(1);
}
size_t memory_snapshot_allocd = 32;
if (!lkm_snapshot)
memory_snapshot = malloc(memory_snapshot_allocd *
sizeof(struct saved_region));
while ((read = getline(&line, &len, fp)) != -1) {
int fields, dev_maj, dev_min, inode;
uint64_t min, max, offset;
char flag_r, flag_w, flag_x, flag_p;
char path[512] = "";
fields = sscanf(line, "%"PRIx64"-%"PRIx64" %c%c%c%c %"PRIx64" %x:%x %d"
" %512s", &min, &max, &flag_r, &flag_w, &flag_x,
&flag_p, &offset, &dev_maj, &dev_min, &inode, path);
if ((fields < 10) || (fields > 11) || !h2g_valid(min))
continue;
int flags = page_get_flags(h2g(min));
max = h2g_valid(max - 1) ? max : (uintptr_t)AFL_G2H(GUEST_ADDR_MAX) + 1;
if (page_check_range(h2g(min), max - min, flags) == -1)
continue;
if (lkm_snapshot) {
afl_snapshot_include_vmrange((void*)min, (void*)max);
} else {
if (!(flags & PROT_WRITE)) continue;
if (memory_snapshot_allocd == memory_snapshot_len) {
memory_snapshot_allocd *= 2;
memory_snapshot = realloc(memory_snapshot, memory_snapshot_allocd *
sizeof(struct saved_region));
}
void* saved = malloc(max - min);
memcpy(saved, (void*)min, max - min);
size_t i = memory_snapshot_len++;
memory_snapshot[i].addr = (void*)min;
memory_snapshot[i].size = max - min;
memory_snapshot[i].saved = saved;
}
}
if (lkm_snapshot)
afl_snapshot_take(AFL_SNAPSHOT_BLOCK | AFL_SNAPSHOT_FDS);
fclose(fp);
}
static void restore_memory_snapshot(void) {
afl_set_brk(saved_brk);
if (lkm_snapshot) {
afl_snapshot_restore();
} else {
size_t i;
for (i = 0; i < memory_snapshot_len; ++i) {
// TODO avoid munmap of snapshot pages
memcpy(memory_snapshot[i].addr, memory_snapshot[i].saved,
memory_snapshot[i].size);
}
}
afl_target_unmap_trackeds();
}
/* Set up SHM region and initialize other stuff. */
static void afl_map_shm_fuzz(void) {
char *id_str = getenv(SHM_FUZZ_ENV_VAR);
if (id_str) {
u32 shm_id = atoi(id_str);
u8 *map = (u8 *)shmat(shm_id, NULL, 0);
/* Whooooops. */
if (!map || map == (void *)-1) {
perror("[AFL] ERROR: could not access fuzzing shared memory");
exit(1);
}
shared_buf_len = (u32 *)map;
shared_buf = map + sizeof(u32);
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "[AFL] DEBUG: successfully got fuzzing shared memory\n");
}
} else {
fprintf(stderr,
"[AFL] ERROR: variable for fuzzing shared memory is not set\n");
exit(1);
}
}
void afl_setup(void) {
char *id_str = getenv(SHM_ENV_VAR), *inst_r = getenv("AFL_INST_RATIO");
int shm_id;
if (inst_r) {
unsigned int r;
r = atoi(inst_r);
if (r > 100) r = 100;
if (!r) r = 1;
afl_inst_rms = MAP_SIZE * r / 100;
}
if (id_str) {
shm_id = atoi(id_str);
afl_area_ptr = shmat(shm_id, NULL, 0);
if (afl_area_ptr == (void *)-1) exit(1);
/* With AFL_INST_RATIO set to a low value, we want to touch the bitmap
so that the parent doesn't give up on us. */
if (inst_r) afl_area_ptr[0] = 1;
}
disable_caching = getenv("AFL_QEMU_DISABLE_CACHE") != NULL;
if (getenv("___AFL_EINS_ZWEI_POLIZEI___")) { // CmpLog forkserver
id_str = getenv(CMPLOG_SHM_ENV_VAR);
if (id_str) {
u32 shm_id = atoi(id_str);
__afl_cmp_map = shmat(shm_id, NULL, 0);
if (__afl_cmp_map == (void *)-1) exit(1);
}
}
if (getenv("AFL_INST_LIBS")) {
afl_start_code = 0;
afl_end_code = (abi_ulong)-1;
}
if (getenv("AFL_CODE_START"))
afl_start_code = strtoll(getenv("AFL_CODE_START"), NULL, 16);
if (getenv("AFL_CODE_END"))
afl_end_code = strtoll(getenv("AFL_CODE_END"), NULL, 16);
int have_names = 0;
if (getenv("AFL_QEMU_INST_RANGES")) {
char *str = getenv("AFL_QEMU_INST_RANGES");
char *saveptr1, *saveptr2 = NULL;
char *pt1, *pt2, *pt3 = NULL;
while (1) {
pt1 = strtok_r(str, ",", &saveptr1);
if (pt1 == NULL) break;
str = NULL;
pt2 = strtok_r(pt1, "-", &saveptr2);
pt3 = strtok_r(NULL, "-", &saveptr2);
struct vmrange* n = calloc(1, sizeof(struct vmrange));
n->next = afl_instr_code;
if (pt3 == NULL) { // filename
have_names = 1;
n->start = (target_ulong)-1;
n->end = 0;
n->name = strdup(pt1);
} else {
n->start = strtoull(pt2, NULL, 16);
n->end = strtoull(pt3, NULL, 16);
n->name = NULL;
}
afl_instr_code = n;
}
}
if (getenv("AFL_QEMU_EXCLUDE_RANGES")) {
char *str = getenv("AFL_QEMU_EXCLUDE_RANGES");
char *saveptr1, *saveptr2 = NULL;
char *pt1, *pt2, *pt3 = NULL;
while (1) {
pt1 = strtok_r(str, ",", &saveptr1);
if (pt1 == NULL) break;
str = NULL;
pt2 = strtok_r(pt1, "-", &saveptr2);
pt3 = strtok_r(NULL, "-", &saveptr2);
struct vmrange* n = calloc(1, sizeof(struct vmrange));
n->exclude = true; // These are "exclusion" regions.
n->next = afl_instr_code;
if (pt3 == NULL) { // filename
have_names = 1;
n->start = (target_ulong)-1;
n->end = 0;
n->name = strdup(pt1);
} else {
n->start = strtoull(pt2, NULL, 16);
n->end = strtoull(pt3, NULL, 16);
n->name = NULL;
}
afl_instr_code = n;
}
}
if (have_names) {
GSList *map_info = read_self_maps();
for (GSList *s = map_info; s; s = g_slist_next(s)) {
MapInfo *e = (MapInfo *) s->data;
if (h2g_valid(e->start)) {
unsigned long min = e->start;
unsigned long max = e->end;
int flags = page_get_flags(h2g(min));
max = h2g_valid(max - 1) ? max : (uintptr_t) AFL_G2H(GUEST_ADDR_MAX) + 1;
if (page_check_range(h2g(min), max - min, flags) == -1) {
continue;
}
// Now that we have a valid guest address region, compare its
// name against the names we care about:
target_ulong gmin = h2g(min);
target_ulong gmax = h2g(max);
struct vmrange* n = afl_instr_code;
while (n) {
if (n->name && strstr(e->path, n->name)) {
if (gmin < n->start) n->start = gmin;
if (gmax > n->end) n->end = gmax;
break;
}
n = n->next;
}
}
}
free_self_maps(map_info);
}
if (getenv("AFL_DEBUG") && afl_instr_code) {
struct vmrange* n = afl_instr_code;
while (n) {
if (n->exclude) {
fprintf(stderr, "Exclude range: 0x%lx-0x%lx (%s)\n",
(unsigned long)n->start, (unsigned long)n->end,
n->name ? n->name : "<noname>");
} else {
fprintf(stderr, "Instrument range: 0x%lx-0x%lx (%s)\n",
(unsigned long)n->start, (unsigned long)n->end,
n->name ? n->name : "<noname>");
}
n = n->next;
}
}
/* Maintain for compatibility */
if (getenv("AFL_QEMU_COMPCOV")) { afl_compcov_level = 1; }
if (getenv("AFL_COMPCOV_LEVEL")) {
afl_compcov_level = atoi(getenv("AFL_COMPCOV_LEVEL"));
}
/* pthread_atfork() seems somewhat broken in util/rcu.c, and I'm
not entirely sure what is the cause. This disables that
behaviour, and seems to work alright? */
rcu_disable_atfork();
if (getenv("AFL_QEMU_PERSISTENT_HOOK")) {
#ifdef AFL_QEMU_STATIC_BUILD
fprintf(stderr,
"[AFL] ERROR: you cannot use AFL_QEMU_PERSISTENT_HOOK when "
"afl-qemu-trace is static\n");
exit(1);
#else
persistent_save_gpr = 1;
void *plib = dlopen(getenv("AFL_QEMU_PERSISTENT_HOOK"), RTLD_NOW);
if (!plib) {
fprintf(stderr, "[AFL] ERROR: invalid AFL_QEMU_PERSISTENT_HOOK=%s\n",
getenv("AFL_QEMU_PERSISTENT_HOOK"));
exit(1);
}
int (*afl_persistent_hook_init_ptr)(void) =
dlsym(plib, "afl_persistent_hook_init");
if (afl_persistent_hook_init_ptr)
sharedmem_fuzzing = afl_persistent_hook_init_ptr();
afl_persistent_hook_ptr = dlsym(plib, "afl_persistent_hook");
if (!afl_persistent_hook_ptr) {
fprintf(stderr,
"[AFL] ERROR: failed to find the function "
"\"afl_persistent_hook\" in %s\n",
getenv("AFL_QEMU_PERSISTENT_HOOK"));
exit(1);
}
#endif
}
if (__afl_cmp_map) return; // no persistent for cmplog
is_persistent = getenv("AFL_QEMU_PERSISTENT_ADDR") != NULL;
if (is_persistent)
afl_persistent_addr = strtoll(getenv("AFL_QEMU_PERSISTENT_ADDR"), NULL, 0);
if (getenv("AFL_QEMU_PERSISTENT_RET"))
afl_persistent_ret_addr =
strtoll(getenv("AFL_QEMU_PERSISTENT_RET"), NULL, 0);
/* If AFL_QEMU_PERSISTENT_RET is not specified patch the return addr */
if (getenv("AFL_QEMU_PERSISTENT_GPR")) persistent_save_gpr = 1;
if (getenv("AFL_QEMU_PERSISTENT_MEM"))
persistent_memory = 1;
if (getenv("AFL_QEMU_PERSISTENT_RETADDR_OFFSET"))
persisent_retaddr_offset =
strtoll(getenv("AFL_QEMU_PERSISTENT_RETADDR_OFFSET"), NULL, 0);
if (getenv("AFL_QEMU_PERSISTENT_CNT"))
afl_persistent_cnt = strtoll(getenv("AFL_QEMU_PERSISTENT_CNT"), NULL, 0);
else
afl_persistent_cnt = 0;
if (getenv("AFL_QEMU_PERSISTENT_EXITS")) persistent_exits = 1;
// TODO persistent exits for other archs not x86
// TODO persistent mode for other archs not x86
// TODO cmplog rtn for arm
if (getenv("AFL_QEMU_SNAPSHOT")) {
is_persistent = 1;
persistent_save_gpr = 1;
persistent_memory = 1;
persistent_exits = 1;
if (afl_persistent_addr == 0)
afl_persistent_addr = strtoll(getenv("AFL_QEMU_SNAPSHOT"), NULL, 0);
}
if (persistent_memory && afl_snapshot_init() >= 0)
lkm_snapshot = 1;
if (getenv("AFL_DEBUG")) {
if (is_persistent)
fprintf(stderr, "Persistent: 0x%lx [0x%lx] %s%s%s\n",
(unsigned long)afl_persistent_addr,
(unsigned long)afl_persistent_ret_addr,
(persistent_save_gpr ? "gpr ": ""),
(persistent_memory ? "mem ": ""),
(persistent_exits ? "exits ": ""));
}
}
/* Fork server logic, invoked once we hit _start. */
void afl_forkserver(CPUState *cpu) {
// u32 map_size = 0;
unsigned char tmp[4] = {0};
if (forkserver_installed == 1) return;
forkserver_installed = 1;
if (getenv("AFL_QEMU_DEBUG_MAPS")) open_self_maps(cpu->env_ptr, 1);
pid_t child_pid;
int t_fd[2];
u8 child_stopped = 0;
u32 was_killed;
int status = 0;
// with the max ID value
if (MAP_SIZE <= FS_OPT_MAX_MAPSIZE)
status |= (FS_OPT_SET_MAPSIZE(MAP_SIZE) | FS_OPT_MAPSIZE);
if (lkm_snapshot) status |= FS_OPT_SNAPSHOT;
if (sharedmem_fuzzing != 0) status |= FS_OPT_SHDMEM_FUZZ;
if (status) status |= (FS_OPT_ENABLED | FS_OPT_NEWCMPLOG);
if (getenv("AFL_DEBUG"))
fprintf(stderr, "Debug: Sending status %08x\n", status);
memcpy(tmp, &status, 4);
/* Tell the parent that we're alive. If the parent doesn't want
to talk, assume that we're not running in forkserver mode. */
if (write(FORKSRV_FD + 1, tmp, 4) != 4) return;
afl_forksrv_pid = getpid();
int first_run = 1;
if (sharedmem_fuzzing) {
if (read(FORKSRV_FD, &was_killed, 4) != 4) exit(2);
if ((was_killed & (0xffffffff & (FS_OPT_ENABLED | FS_OPT_SHDMEM_FUZZ))) ==
(FS_OPT_ENABLED | FS_OPT_SHDMEM_FUZZ))
afl_map_shm_fuzz();
else {
fprintf(stderr,
"[AFL] ERROR: afl-fuzz is old and does not support"
" shmem input");
exit(1);
}
}
/* All right, let's await orders... */
while (1) {
/* Whoops, parent dead? */
if (read(FORKSRV_FD, &was_killed, 4) != 4) exit(2);
/* If we stopped the child in persistent mode, but there was a race
condition and afl-fuzz already issued SIGKILL, write off the old
process. */
if (child_stopped && was_killed) {
child_stopped = 0;
if (waitpid(child_pid, &status, 0) < 0) exit(8);
}
if (!child_stopped) {
/* Establish a channel with child to grab translation commands. We'll
read from t_fd[0], child will write to TSL_FD. */
if (pipe(t_fd) || dup2(t_fd[1], TSL_FD) < 0) exit(3);
close(t_fd[1]);
child_pid = fork();
if (child_pid < 0) exit(4);
if (!child_pid) {
/* Child process. Close descriptors and run free. */
afl_fork_child = 1;
close(FORKSRV_FD);
close(FORKSRV_FD + 1);
close(t_fd[0]);
return;
}
/* Parent. */
close(TSL_FD);
} else {
/* Special handling for persistent mode: if the child is alive but
currently stopped, simply restart it with SIGCONT. */
kill(child_pid, SIGCONT);
child_stopped = 0;
}
/* Parent. */
if (write(FORKSRV_FD + 1, &child_pid, 4) != 4) exit(5);
/* Collect translation requests until child dies and closes the pipe. */
afl_wait_tsl(cpu, t_fd[0]);
/* Get and relay exit status to parent. */
if (waitpid(child_pid, &status, is_persistent ? WUNTRACED : 0) < 0) exit(6);
/* In persistent mode, the child stops itself with SIGSTOP to indicate
a successful run. In this case, we want to wake it up without forking
again. */
if (WIFSTOPPED(status))
child_stopped = 1;
else if (unlikely(first_run && is_persistent)) {
fprintf(stderr, "[AFL] ERROR: no persistent iteration executed\n");
exit(12); // Persistent is wrong
}
first_run = 0;
if (write(FORKSRV_FD + 1, &status, 4) != 4) exit(7);
}
}
/* A simplified persistent mode handler, used as explained in
* llvm_mode/README.md. */
static u32 cycle_cnt;
void afl_persistent_iter(CPUArchState *env) {
static struct afl_tsl exit_cmd_tsl;
if (!afl_persistent_cnt || --cycle_cnt) {
if (persistent_memory) restore_memory_snapshot();
if (persistent_save_gpr && !afl_persistent_hook_ptr) {
afl_restore_regs(&saved_regs, env);
}
if (!disable_caching) {
memset(&exit_cmd_tsl, 0, sizeof(struct afl_tsl));
exit_cmd_tsl.tb.pc = (target_ulong)(-1);
if (write(TSL_FD, &exit_cmd_tsl, sizeof(struct afl_tsl)) !=
sizeof(struct afl_tsl)) {
/* Exit the persistent loop on pipe error */
afl_area_ptr = dummy;
exit(0);
}
}
// TODO use only pipe
raise(SIGSTOP);
// now we have shared_buf updated and ready to use
if (persistent_save_gpr && afl_persistent_hook_ptr) {
struct api_regs hook_regs = saved_regs;
afl_persistent_hook_ptr(&hook_regs, guest_base, shared_buf,
*shared_buf_len);
afl_restore_regs(&hook_regs, env);
}
afl_area_ptr[0] = 1;
afl_prev_loc = 0;
} else {
afl_area_ptr = dummy;
exit(0);
}
}
void afl_persistent_loop(CPUArchState *env) {
if (!afl_fork_child) return;
if (persistent_first_pass) {
/* Make sure that every iteration of __AFL_LOOP() starts with a clean slate.
On subsequent calls, the parent will take care of that, but on the first
iteration, it's our job to erase any trace of whatever happened
before the loop. */
if (is_persistent) {
memset(afl_area_ptr, 0, MAP_SIZE);
afl_area_ptr[0] = 1;
afl_prev_loc = 0;
}
if (persistent_memory) collect_memory_snapshot();
if (persistent_save_gpr) {
afl_save_regs(&saved_regs, env);
if (afl_persistent_hook_ptr) {
struct api_regs hook_regs = saved_regs;
afl_persistent_hook_ptr(&hook_regs, guest_base, shared_buf,
*shared_buf_len);
afl_restore_regs(&hook_regs, env);
}
}
cycle_cnt = afl_persistent_cnt;
persistent_first_pass = 0;
persistent_stack_offset = TARGET_LONG_BITS / 8;
return;
}
if (is_persistent) {
afl_persistent_iter(env);
}
}
/* This code is invoked whenever QEMU decides that it doesn't have a
translation of a particular block and needs to compute it, or when it
decides to chain two TBs together. When this happens, we tell the parent to
mirror the operation, so that the next fork() has a cached copy. */
static void afl_request_tsl(target_ulong pc, target_ulong cb, uint32_t flags,
uint32_t cf_mask, TranslationBlock *last_tb,
int tb_exit) {
if (disable_caching) return;
struct afl_tsl t;
if (!afl_fork_child) return;
t.tb.pc = pc;
t.tb.cs_base = cb;
t.tb.flags = flags;
t.tb.cf_mask = cf_mask;
t.is_chain = (last_tb != NULL);
if (t.is_chain) {
t.chain.last_tb.pc = last_tb->pc;
t.chain.last_tb.cs_base = last_tb->cs_base;
t.chain.last_tb.flags = last_tb->flags;
t.chain.cf_mask = cf_mask;
t.chain.tb_exit = tb_exit;
}
if (write(TSL_FD, &t, sizeof(struct afl_tsl)) != sizeof(struct afl_tsl))
return;
}
static inline TranslationBlock *
afl_tb_lookup(CPUState *cpu, target_ulong pc, target_ulong cs_base,
uint32_t flags, uint32_t cf_mask)
{
TranslationBlock *tb;
uint32_t hash;
hash = tb_jmp_cache_hash_func(pc);
tb = qatomic_rcu_read(&cpu->tb_jmp_cache[hash]);
cf_mask &= ~CF_CLUSTER_MASK;
cf_mask |= cpu->cluster_index << CF_CLUSTER_SHIFT;
if (likely(tb &&
tb->pc == pc &&
tb->cs_base == cs_base &&
tb->flags == flags &&
tb->trace_vcpu_dstate == *cpu->trace_dstate &&
(tb_cflags(tb) & (CF_HASH_MASK | CF_INVALID)) == cf_mask)) {
return tb;
}
tb = tb_htable_lookup(cpu, pc, cs_base, flags, cf_mask);
if (tb == NULL) {
return NULL;
}
qatomic_set(&cpu->tb_jmp_cache[hash], tb);
return tb;
}
/* This is the other side of the same channel. Since timeouts are handled by
afl-fuzz simply killing the child, we can just wait until the pipe breaks. */
static void afl_wait_tsl(CPUState *cpu, int fd) {
struct afl_tsl t;
TranslationBlock *tb, *last_tb;
if (disable_caching) return;
while (1) {
u8 invalid_pc = 0;
/* Broken pipe means it's time to return to the fork server routine. */
if (read(fd, &t, sizeof(struct afl_tsl)) != sizeof(struct afl_tsl)) break;
/* Exit command for persistent */
if (t.tb.pc == (target_ulong)(-1)) return;
tb = afl_tb_lookup(cpu, t.tb.pc, t.tb.cs_base, t.tb.flags, t.tb.cf_mask);
if (!tb) {
/* The child may request to transate a block of memory that is not
mapped in the parent (e.g. jitted code or dlopened code).
This causes a SIGSEV in gen_intermediate_code() and associated
subroutines. We simply avoid caching of such blocks. */
if (is_valid_addr(t.tb.pc)) {
mmap_lock();
tb = tb_gen_code(cpu, t.tb.pc, t.tb.cs_base, t.tb.flags, t.tb.cf_mask);
mmap_unlock();
} else {
invalid_pc = 1;
}
}
if (t.is_chain && !invalid_pc) {
last_tb = afl_tb_lookup(cpu, t.chain.last_tb.pc,
t.chain.last_tb.cs_base,
t.chain.last_tb.flags,
t.chain.cf_mask);
#define TB_JMP_RESET_OFFSET_INVALID 0xffff
if (last_tb && (last_tb->jmp_reset_offset[t.chain.tb_exit] !=
TB_JMP_RESET_OFFSET_INVALID)) {
tb_add_jump(last_tb, t.chain.tb_exit, tb);
}
}
}
close(fd);
}
/* -icount align implementation. */
typedef struct SyncClocks {
int64_t diff_clk;
int64_t last_cpu_icount;
int64_t realtime_clock;
} SyncClocks;
#if !defined(CONFIG_USER_ONLY)
/* Allow the guest to have a max 3ms advance.