core: add a lightweight spinlock to protect the list of file descriptors.

This commit is contained in:
Sam Hocevar 2014-10-31 10:48:46 +00:00 committed by sam
parent 01297f5a6e
commit fd7e90d858

View File

@ -69,6 +69,21 @@ static struct files
static int *fds, static_fds[STATIC_FILES];
static int maxfd, nfiles;
/* Spinlock. This variable protects the fds variable. */
static volatile int fd_spinlock = 0;
static void fd_lock()
{
while (__sync_lock_test_and_set(&fd_spinlock, 1))
;
}
static void fd_unlock()
{
__sync_synchronize();
fd_spinlock = 0;
}
/* Create lock. This lock variable is used to disable file descriptor
* creation wrappers. For instance on Mac OS X, fopen() calls open()
* and we dont want open() to do any zzuf-related stuff: fopen() takes
@ -83,7 +98,7 @@ static int autoinc = 0;
void _zz_include(char const *regex)
{
#if defined HAVE_REGEX_H
if(regcomp(&re_include, regex, REG_EXTENDED) == 0)
if (regcomp(&re_include, regex, REG_EXTENDED) == 0)
has_include = 1;
#else
(void)regex;
@ -93,7 +108,7 @@ void _zz_include(char const *regex)
void _zz_exclude(char const *regex)
{
#if defined HAVE_REGEX_H
if(regcomp(&re_exclude, regex, REG_EXTENDED) == 0)
if (regcomp(&re_exclude, regex, REG_EXTENDED) == 0)
has_exclude = 1;
#else
(void)regex;
@ -112,7 +127,7 @@ void _zz_setseed(int32_t s)
void _zz_setratio(double r0, double r1)
{
if(r0 == 0.0 && r1 == 0.0)
if (r0 == 0.0 && r1 == 0.0)
{
maxratio = minratio = 0.0;
return;
@ -120,7 +135,7 @@ void _zz_setratio(double r0, double r1)
minratio = r0 < MIN_RATIO ? MIN_RATIO : r0 > MAX_RATIO ? MAX_RATIO : r0;
maxratio = r1 < MIN_RATIO ? MIN_RATIO : r1 > MAX_RATIO ? MAX_RATIO : r1;
if(maxratio < minratio)
if (maxratio < minratio)
maxratio = minratio;
}
@ -134,7 +149,7 @@ double _zz_getratio(void)
uint16_t rate;
double min, max, cur;
if(minratio == maxratio)
if (minratio == maxratio)
return minratio; /* this also takes care of 0.0 */
rate = shuffle[seed & 0xf] << 12;
@ -161,11 +176,11 @@ void _zz_fd_init(void)
* calls to malloc() that we do, so we get better chances that memory
* corruption errors are reproducible */
files = static_files;
for(nfiles = 0; nfiles < 32; nfiles++)
for (nfiles = 0; nfiles < 32; nfiles++)
files[nfiles].managed = 0;
fds = static_fds;
for(maxfd = 0; maxfd < 32; maxfd++)
for (maxfd = 0; maxfd < 32; maxfd++)
fds[maxfd] = -1;
}
@ -173,9 +188,9 @@ void _zz_fd_fini(void)
{
int i;
for(i = 0; i < maxfd; i++)
for (i = 0; i < maxfd; i++)
{
if(!files[fds[i]].managed)
if (!files[fds[i]].managed)
continue;
/* XXX: What are we supposed to do? If filedescriptors weren't
@ -183,27 +198,27 @@ void _zz_fd_fini(void)
}
#if defined HAVE_REGEX_H
if(has_include)
if (has_include)
regfree(&re_include);
if(has_exclude)
if (has_exclude)
regfree(&re_exclude);
#endif
if(files != static_files)
if (files != static_files)
free(files);
if(fds != static_fds)
if (fds != static_fds)
free(fds);
if(list != static_list)
if (list != static_list)
free(list);
}
int _zz_mustwatch(char const *file)
{
#if defined HAVE_REGEXEC
if(has_include && regexec(&re_include, file, 0, NULL, 0) == REG_NOMATCH)
if (has_include && regexec(&re_include, file, 0, NULL, 0) == REG_NOMATCH)
return 0; /* not included: ignore */
if(has_exclude && regexec(&re_exclude, file, 0, NULL, 0) != REG_NOMATCH)
if (has_exclude && regexec(&re_exclude, file, 0, NULL, 0) != REG_NOMATCH)
return 0; /* excluded: ignore */
#else
(void)file;
@ -215,10 +230,10 @@ int _zz_mustwatch(char const *file)
int _zz_mustwatchw(wchar_t const *file)
{
#if defined HAVE_REGWEXEC
if(has_include && regwexec(&re_include, file, 0, NULL, 0) == REG_NOMATCH)
if (has_include && regwexec(&re_include, file, 0, NULL, 0) == REG_NOMATCH)
return 0; /* not included: ignore */
if(has_exclude && regwexec(&re_exclude, file, 0, NULL, 0) != REG_NOMATCH)
if (has_exclude && regwexec(&re_exclude, file, 0, NULL, 0) != REG_NOMATCH)
return 0; /* excluded: ignore */
#else
(void)file;
@ -229,49 +244,58 @@ int _zz_mustwatchw(wchar_t const *file)
int _zz_iswatched(int fd)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return 0;
int ret = 0;
fd_lock();
return 1;
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
ret = 1;
early_exit:
fd_unlock();
return ret;
}
void _zz_register(int fd)
{
int i;
if(fd < 0 || fd > 65535 || (fd < maxfd && fds[fd] != -1))
return;
fd_lock();
if (fd < 0 || fd > 65535 || (fd < maxfd && fds[fd] != -1))
goto early_exit;
#if defined LIBZZUF
if(autoinc)
if (autoinc)
debug2("using seed %li", (long int)seed);
#endif
/* If filedescriptor is outside our bounds */
while(fd >= maxfd)
while (fd >= maxfd)
{
if(fds == static_fds)
if (fds == static_fds)
{
fds = malloc(2 * maxfd * sizeof(*fds));
memcpy(fds, static_fds, maxfd * sizeof(*fds));
}
else
fds = realloc(fds, 2 * maxfd * sizeof(*fds));
for(i = maxfd; i < maxfd * 2; i++)
for (i = maxfd; i < maxfd * 2; i++)
fds[i] = -1;
maxfd *= 2;
}
/* Find an empty slot */
for(i = 0; i < nfiles; i++)
if(files[i].managed == 0)
for (i = 0; i < nfiles; i++)
if (files[i].managed == 0)
break;
/* No slot found, allocate memory */
if(i == nfiles)
if (i == nfiles)
{
nfiles++;
if(files == static_files)
if (files == static_files)
{
files = malloc(nfiles * sizeof(*files));
memcpy(files, static_files, nfiles * sizeof(*files));
@ -292,7 +316,7 @@ void _zz_register(int fd)
files[i].fuzz.uflag = 0;
/* Check whether we should ignore the fd */
if(list)
if (list)
{
static int idx = 0;
@ -301,100 +325,151 @@ void _zz_register(int fd)
else
files[i].active = 1;
if(autoinc)
if (autoinc)
seed++;
fds[fd] = i;
early_exit:
fd_unlock();
}
void _zz_unregister(int fd)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return;
fd_lock();
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
files[fds[fd]].managed = 0;
#if defined HAVE_FGETLN
if(files[fds[fd]].fuzz.tmp)
if (files[fds[fd]].fuzz.tmp)
free(files[fds[fd]].fuzz.tmp);
#endif
fds[fd] = -1;
early_exit:
fd_unlock();
}
void _zz_lock(int fd)
{
if(fd < -1 || fd >= maxfd || fds[fd] == -1)
return;
fd_lock();
if(fd == -1)
if (fd < -1 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
if (fd == -1)
create_lock++;
else
files[fds[fd]].locked++;
early_exit:
fd_unlock();
}
void _zz_unlock(int fd)
{
if(fd < -1 || fd >= maxfd || fds[fd] == -1)
return;
fd_lock();
if(fd == -1)
if (fd < -1 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
if (fd == -1)
create_lock--;
else
files[fds[fd]].locked--;
early_exit:
fd_unlock();
}
int _zz_islocked(int fd)
{
if(fd < -1 || fd >= maxfd || fds[fd] == -1)
return 0;
int ret = 0;
fd_lock();
if(fd == -1)
return create_lock;
if (fd < -1 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
if (fd == -1)
ret = create_lock;
else
return files[fds[fd]].locked;
ret = files[fds[fd]].locked;
early_exit:
fd_unlock();
return ret;
}
int _zz_isactive(int fd)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return 1;
int ret = 1;
fd_lock();
return files[fds[fd]].active;
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
ret = files[fds[fd]].active;
early_exit:
fd_unlock();
return ret;
}
int64_t _zz_getpos(int fd)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return 0;
int ret = 0;
fd_lock();
return files[fds[fd]].pos;
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
ret = files[fds[fd]].pos;
early_exit:
fd_unlock();
return ret;
}
void _zz_setpos(int fd, int64_t pos)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return;
fd_lock();
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
files[fds[fd]].pos = pos;
early_exit:
fd_unlock();
}
void _zz_addpos(int fd, int64_t off)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return;
fd_lock();
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
files[fds[fd]].pos += off;
early_exit:
fd_unlock();
}
void _zz_setfuzzed(int fd, int count)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return;
fd_lock();
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
/* FIXME: what if we just slightly advanced? */
if(files[fds[fd]].pos == files[fds[fd]].already_pos
if (files[fds[fd]].pos == files[fds[fd]].already_pos
&& count <= files[fds[fd]].already_fuzzed)
return;
goto early_exit;
#if defined LIBZZUF
debug2("setfuzzed(%i, %i)", fd, count);
@ -402,29 +477,46 @@ void _zz_setfuzzed(int fd, int count)
files[fds[fd]].already_pos = files[fds[fd]].pos;
files[fds[fd]].already_fuzzed = count;
early_exit:
fd_unlock();
}
int _zz_getfuzzed(int fd)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return 0;
int ret = 0;
fd_lock();
if(files[fds[fd]].pos < files[fds[fd]].already_pos)
return 0;
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
if(files[fds[fd]].pos >= files[fds[fd]].already_pos
if (files[fds[fd]].pos < files[fds[fd]].already_pos)
goto early_exit;
if (files[fds[fd]].pos >= files[fds[fd]].already_pos
+ files[fds[fd]].already_fuzzed)
return 0;
goto early_exit;
return (int)(files[fds[fd]].already_fuzzed + files[fds[fd]].already_pos
- files[fds[fd]].pos);
ret = (int)(files[fds[fd]].already_fuzzed + files[fds[fd]].already_pos
- files[fds[fd]].pos);
early_exit:
fd_unlock();
return ret;
}
struct fuzz *_zz_getfuzz(int fd)
{
if(fd < 0 || fd >= maxfd || fds[fd] == -1)
return NULL;
struct fuzz *ret = NULL;
fd_lock();
return &files[fds[fd]].fuzz;
if (fd < 0 || fd >= maxfd || fds[fd] == -1)
goto early_exit;
ret = &files[fds[fd]].fuzz;
early_exit:
fd_unlock();
return ret;
}