Author: markj
Date: Sat Aug 24 21:07:04 2013
New Revision: 254810
URL: http://svnweb.freebsd.org/changeset/base/254810
Log:
Remove the kld lock macros and just use the sx(9) API. Add locking in
linker_init_kernel_modules() and linker_preload() in order to remove most
of the checks for !cold before asserting that the kld lock is held. These
routines are invoked by SYSINIT(9), so there's no harm in them taking the
kld lock.
Modified:
head/sys/kern/kern_linker.c
Modified: head/sys/kern/kern_linker.c
==============================================================================
--- head/sys/kern/kern_linker.c Sat Aug 24 21:04:54 2013 (r254809)
+++ head/sys/kern/kern_linker.c Sat Aug 24 21:07:04 2013 (r254810)
@@ -71,17 +71,6 @@ SYSCTL_INT(_debug, OID_AUTO, kld_debug,
TUNABLE_INT("debug.kld_debug", &kld_debug);
#endif
-#define KLD_LOCK() sx_xlock(&kld_sx)
-#define KLD_UNLOCK() sx_xunlock(&kld_sx)
-#define KLD_DOWNGRADE() sx_downgrade(&kld_sx)
-#define KLD_LOCK_READ() sx_slock(&kld_sx)
-#define KLD_UNLOCK_READ() sx_sunlock(&kld_sx)
-#define KLD_LOCKED() sx_xlocked(&kld_sx)
-#define KLD_LOCK_ASSERT() do {
\
- if (!cold) \
- sx_assert(&kld_sx, SX_XLOCKED); \
-} while (0)
-
/*
* static char *linker_search_path(const char *name, struct mod_depend
* *verinfo);
@@ -121,7 +110,8 @@ static int linker_no_more_classes = 0;
#define LINKER_GET_NEXT_FILE_ID(a) do {
\
linker_file_t lftmp; \
\
- KLD_LOCK_ASSERT(); \
+ if (!cold) \
+ sx_assert(&kld_sx, SA_XLOCKED); \
retry: \
TAILQ_FOREACH(lftmp, &linker_files, link) { \
if (next_file_id == lftmp->id) { \
@@ -360,7 +350,9 @@ static void
linker_init_kernel_modules(void)
{
+ sx_xlock(&kld_sx);
linker_file_register_modules(linker_kernel_file);
+ sx_xunlock(&kld_sx);
}
SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
@@ -377,7 +369,7 @@ linker_load_file(const char *filename, l
if (prison0.pr_securelevel > 0)
return (EPERM);
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
lf = linker_find_file_by_name(filename);
if (lf) {
KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
@@ -411,10 +403,10 @@ linker_load_file(const char *filename, l
return (error);
}
modules = !TAILQ_EMPTY(&lf->modules);
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
linker_file_register_sysctls(lf);
linker_file_sysinit(lf);
- KLD_LOCK();
+ sx_xlock(&kld_sx);
lf->flags |= LINKER_FILE_LINKED;
/*
@@ -465,16 +457,16 @@ linker_reference_module(const char *modn
modlist_t mod;
int error;
- KLD_LOCK();
+ sx_xlock(&kld_sx);
if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
*result = mod->container;
(*result)->refs++;
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (0);
}
error = linker_load_module(NULL, modname, NULL, verinfo, result);
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
@@ -485,13 +477,13 @@ linker_release_module(const char *modnam
modlist_t mod;
int error;
- KLD_LOCK();
+ sx_xlock(&kld_sx);
if (lf == NULL) {
KASSERT(modname != NULL,
("linker_release_module: no file or name"));
mod = modlist_lookup2(modname, verinfo);
if (mod == NULL) {
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (ESRCH);
}
lf = mod->container;
@@ -499,7 +491,7 @@ linker_release_module(const char *modnam
KASSERT(modname == NULL && verinfo == NULL,
("linker_release_module: both file and name"));
error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
@@ -512,7 +504,7 @@ linker_find_file_by_name(const char *fil
koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
sprintf(koname, "%s.ko", filename);
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
TAILQ_FOREACH(lf, &linker_files, link) {
if (strcmp(lf->filename, koname) == 0)
break;
@@ -528,7 +520,7 @@ linker_find_file_by_id(int fileid)
{
linker_file_t lf;
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
TAILQ_FOREACH(lf, &linker_files, link)
if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
break;
@@ -541,13 +533,13 @@ linker_file_foreach(linker_predicate_t *
linker_file_t lf;
int retval = 0;
- KLD_LOCK();
+ sx_xlock(&kld_sx);
TAILQ_FOREACH(lf, &linker_files, link) {
retval = predicate(lf, context);
if (retval != 0)
break;
}
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (retval);
}
@@ -557,7 +549,8 @@ linker_make_file(const char *pathname, l
linker_file_t lf;
const char *filename;
- KLD_LOCK_ASSERT();
+ if (!cold)
+ sx_assert(&kld_sx, SA_XLOCKED);
filename = linker_basename(pathname);
KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for
pathname='%s'\n", filename, pathname));
@@ -591,7 +584,7 @@ linker_file_unload(linker_file_t file, i
if (prison0.pr_securelevel > 0)
return (EPERM);
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
/* Easy case of just dropping a reference. */
@@ -664,10 +657,10 @@ linker_file_unload(linker_file_t file, i
*/
if (file->flags & LINKER_FILE_LINKED) {
file->flags &= ~LINKER_FILE_LINKED;
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
linker_file_sysuninit(file);
linker_file_unregister_sysctls(file);
- KLD_LOCK();
+ sx_xlock(&kld_sx);
}
TAILQ_REMOVE(&linker_files, file, link);
@@ -706,7 +699,7 @@ linker_file_add_dependency(linker_file_t
{
linker_file_t *newdeps;
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
M_LINKER, M_WAITOK | M_ZERO);
if (newdeps == NULL)
@@ -738,12 +731,12 @@ linker_file_lookup_set(linker_file_t fil
{
int error, locked;
- locked = KLD_LOCKED();
+ locked = sx_xlocked(&kld_sx);
if (!locked)
- KLD_LOCK();
+ sx_xlock(&kld_sx);
error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
if (!locked)
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
@@ -763,12 +756,12 @@ linker_file_lookup_symbol(linker_file_t
caddr_t sym;
int locked;
- locked = KLD_LOCKED();
+ locked = sx_xlocked(&kld_sx);
if (!locked)
- KLD_LOCK();
+ sx_xlock(&kld_sx);
sym = linker_file_lookup_symbol_internal(file, name, deps);
if (!locked)
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (sym);
}
@@ -782,7 +775,7 @@ linker_file_lookup_symbol_internal(linke
size_t common_size = 0;
int i;
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
file, name, deps));
@@ -982,9 +975,9 @@ linker_search_symbol_name(caddr_t value,
{
int error;
- KLD_LOCK();
+ sx_xlock(&kld_sx);
error = linker_debug_search_symbol_name(value, buf, buflen, offset);
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
@@ -1026,10 +1019,10 @@ kern_kldload(struct thread *td, const ch
modname = file;
}
- KLD_LOCK();
+ sx_xlock(&kld_sx);
error = linker_load_module(kldname, modname, NULL, NULL, &lf);
if (error) {
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
goto done;
}
lf->userrefs++;
@@ -1039,13 +1032,13 @@ kern_kldload(struct thread *td, const ch
EVENTHANDLER_INVOKE(kld_load, lf);
#ifdef HWPMC_HOOKS
- KLD_DOWNGRADE();
+ sx_downgrade(&kld_sx);
pkm.pm_file = lf->filename;
pkm.pm_address = (uintptr_t) lf->address;
PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
- KLD_UNLOCK_READ();
+ sx_sunlock(&kld_sx);
#else
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
#endif
done:
@@ -1088,7 +1081,7 @@ kern_kldunload(struct thread *td, int fi
return (error);
CURVNET_SET(TD_TO_VNET(td));
- KLD_LOCK();
+ sx_xlock(&kld_sx);
lf = linker_find_file_by_id(fileid);
if (lf) {
KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
@@ -1119,13 +1112,13 @@ kern_kldunload(struct thread *td, int fi
#ifdef HWPMC_HOOKS
if (error == 0) {
- KLD_DOWNGRADE();
+ sx_downgrade(&kld_sx);
PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
- KLD_UNLOCK_READ();
+ sx_sunlock(&kld_sx);
} else
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
#else
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
#endif
CURVNET_RESTORE();
return (error);
@@ -1169,13 +1162,13 @@ sys_kldfind(struct thread *td, struct kl
goto out;
filename = linker_basename(pathname);
- KLD_LOCK();
+ sx_xlock(&kld_sx);
lf = linker_find_file_by_name(filename);
if (lf)
td->td_retval[0] = lf->id;
else
error = ENOENT;
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
out:
free(pathname, M_TEMP);
return (error);
@@ -1193,7 +1186,7 @@ sys_kldnext(struct thread *td, struct kl
return (error);
#endif
- KLD_LOCK();
+ sx_xlock(&kld_sx);
if (uap->fileid == 0)
lf = TAILQ_FIRST(&linker_files);
else {
@@ -1214,7 +1207,7 @@ sys_kldnext(struct thread *td, struct kl
else
td->td_retval[0] = 0;
out:
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
@@ -1253,10 +1246,10 @@ kern_kldstat(struct thread *td, int file
return (error);
#endif
- KLD_LOCK();
+ sx_xlock(&kld_sx);
lf = linker_find_file_by_id(fileid);
if (lf == NULL) {
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (ENOENT);
}
@@ -1274,7 +1267,7 @@ kern_kldstat(struct thread *td, int file
if (namelen > MAXPATHLEN)
namelen = MAXPATHLEN;
bcopy(lf->pathname, &stat->pathname[0], namelen);
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
td->td_retval[0] = 0;
return (0);
@@ -1293,7 +1286,7 @@ sys_kldfirstmod(struct thread *td, struc
return (error);
#endif
- KLD_LOCK();
+ sx_xlock(&kld_sx);
lf = linker_find_file_by_id(uap->fileid);
if (lf) {
MOD_SLOCK;
@@ -1305,7 +1298,7 @@ sys_kldfirstmod(struct thread *td, struc
MOD_SUNLOCK;
} else
error = ENOENT;
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
@@ -1333,7 +1326,7 @@ sys_kldsym(struct thread *td, struct kld
symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
goto out;
- KLD_LOCK();
+ sx_xlock(&kld_sx);
if (uap->fileid != 0) {
lf = linker_find_file_by_id(uap->fileid);
if (lf == NULL)
@@ -1359,7 +1352,7 @@ sys_kldsym(struct thread *td, struct kld
if (lf == NULL)
error = ENOENT;
}
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
out:
free(symstr, M_TEMP);
return (error);
@@ -1468,6 +1461,7 @@ linker_preload(void *arg)
error = 0;
modptr = NULL;
+ sx_xlock(&kld_sx);
while ((modptr = preload_search_next_name(modptr)) != NULL) {
modname = (char *)preload_search_info(modptr, MODINFO_NAME);
modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
@@ -1649,6 +1643,7 @@ fail:
TAILQ_REMOVE(&depended_files, lf, loaded);
linker_file_unload(lf, LINKER_UNLOAD_FORCE);
}
+ sx_xunlock(&kld_sx);
/* woohoo! we made it! */
}
@@ -1948,7 +1943,7 @@ linker_hwpmc_list_objects(void)
int i, nmappings;
nmappings = 0;
- KLD_LOCK_READ();
+ sx_slock(&kld_sx);
TAILQ_FOREACH(lf, &linker_files, link)
nmappings++;
@@ -1963,7 +1958,7 @@ linker_hwpmc_list_objects(void)
kobase[i].pm_address = (uintptr_t)lf->address;
i++;
}
- KLD_UNLOCK_READ();
+ sx_sunlock(&kld_sx);
KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
@@ -1989,7 +1984,7 @@ linker_load_module(const char *kldname,
char *pathname;
int error;
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
if (modname == NULL) {
/*
* We have to load KLD
@@ -2063,7 +2058,7 @@ linker_load_dependencies(linker_file_t l
/*
* All files are dependant on /kernel.
*/
- KLD_LOCK_ASSERT();
+ sx_assert(&kld_sx, SA_XLOCKED);
if (linker_kernel_file) {
linker_kernel_file->refs++;
error = linker_file_add_dependency(lf, linker_kernel_file);
@@ -2155,16 +2150,16 @@ sysctl_kern_function_list(SYSCTL_HANDLER
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
- KLD_LOCK();
+ sx_xlock(&kld_sx);
TAILQ_FOREACH(lf, &linker_files, link) {
error = LINKER_EACH_FUNCTION_NAME(lf,
sysctl_kern_function_list_iterate, req);
if (error) {
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (error);
}
}
- KLD_UNLOCK();
+ sx_xunlock(&kld_sx);
return (SYSCTL_OUT(req, "", 1));
}
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