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.
This commit is contained in:
Mark Johnston
parent
1f97b64cbb
commit
3a277424e6
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=254810
@ -71,17 +71,6 @@ SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW | CTLFLAG_TUN,
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TUNABLE_INT("debug.kld_debug", &kld_debug);
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#endif
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#define KLD_LOCK() sx_xlock(&kld_sx)
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#define KLD_UNLOCK() sx_xunlock(&kld_sx)
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#define KLD_DOWNGRADE() sx_downgrade(&kld_sx)
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#define KLD_LOCK_READ() sx_slock(&kld_sx)
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#define KLD_UNLOCK_READ() sx_sunlock(&kld_sx)
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#define KLD_LOCKED() sx_xlocked(&kld_sx)
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#define KLD_LOCK_ASSERT() do { \
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if (!cold) \
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sx_assert(&kld_sx, SX_XLOCKED); \
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} while (0)
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/*
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* static char *linker_search_path(const char *name, struct mod_depend
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* *verinfo);
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@ -121,7 +110,8 @@ static int linker_no_more_classes = 0;
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#define LINKER_GET_NEXT_FILE_ID(a) do { \
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linker_file_t lftmp; \
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\
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KLD_LOCK_ASSERT(); \
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if (!cold) \
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sx_assert(&kld_sx, SA_XLOCKED); \
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retry: \
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TAILQ_FOREACH(lftmp, &linker_files, link) { \
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if (next_file_id == lftmp->id) { \
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@ -360,7 +350,9 @@ static void
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linker_init_kernel_modules(void)
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{
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sx_xlock(&kld_sx);
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linker_file_register_modules(linker_kernel_file);
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sx_xunlock(&kld_sx);
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}
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SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
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@ -377,7 +369,7 @@ linker_load_file(const char *filename, linker_file_t *result)
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if (prison0.pr_securelevel > 0)
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return (EPERM);
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KLD_LOCK_ASSERT();
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sx_assert(&kld_sx, SA_XLOCKED);
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lf = linker_find_file_by_name(filename);
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if (lf) {
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KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
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@ -411,10 +403,10 @@ linker_load_file(const char *filename, linker_file_t *result)
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return (error);
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}
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modules = !TAILQ_EMPTY(&lf->modules);
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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linker_file_register_sysctls(lf);
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linker_file_sysinit(lf);
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KLD_LOCK();
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sx_xlock(&kld_sx);
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lf->flags |= LINKER_FILE_LINKED;
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/*
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@ -465,16 +457,16 @@ linker_reference_module(const char *modname, struct mod_depend *verinfo,
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modlist_t mod;
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int error;
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KLD_LOCK();
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sx_xlock(&kld_sx);
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if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
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*result = mod->container;
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(*result)->refs++;
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (0);
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}
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error = linker_load_module(NULL, modname, NULL, verinfo, result);
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (error);
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}
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@ -485,13 +477,13 @@ linker_release_module(const char *modname, struct mod_depend *verinfo,
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modlist_t mod;
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int error;
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KLD_LOCK();
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sx_xlock(&kld_sx);
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if (lf == NULL) {
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KASSERT(modname != NULL,
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("linker_release_module: no file or name"));
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mod = modlist_lookup2(modname, verinfo);
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if (mod == NULL) {
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (ESRCH);
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}
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lf = mod->container;
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@ -499,7 +491,7 @@ linker_release_module(const char *modname, struct mod_depend *verinfo,
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KASSERT(modname == NULL && verinfo == NULL,
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("linker_release_module: both file and name"));
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error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (error);
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}
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@ -512,7 +504,7 @@ linker_find_file_by_name(const char *filename)
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koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
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sprintf(koname, "%s.ko", filename);
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KLD_LOCK_ASSERT();
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sx_assert(&kld_sx, SA_XLOCKED);
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TAILQ_FOREACH(lf, &linker_files, link) {
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if (strcmp(lf->filename, koname) == 0)
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break;
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@ -528,7 +520,7 @@ linker_find_file_by_id(int fileid)
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{
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linker_file_t lf;
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KLD_LOCK_ASSERT();
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sx_assert(&kld_sx, SA_XLOCKED);
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TAILQ_FOREACH(lf, &linker_files, link)
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if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
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break;
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@ -541,13 +533,13 @@ linker_file_foreach(linker_predicate_t *predicate, void *context)
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linker_file_t lf;
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int retval = 0;
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KLD_LOCK();
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sx_xlock(&kld_sx);
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TAILQ_FOREACH(lf, &linker_files, link) {
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retval = predicate(lf, context);
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if (retval != 0)
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break;
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}
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (retval);
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}
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@ -557,7 +549,8 @@ linker_make_file(const char *pathname, linker_class_t lc)
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linker_file_t lf;
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const char *filename;
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KLD_LOCK_ASSERT();
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if (!cold)
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sx_assert(&kld_sx, SA_XLOCKED);
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filename = linker_basename(pathname);
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KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
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@ -591,7 +584,7 @@ linker_file_unload(linker_file_t file, int flags)
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if (prison0.pr_securelevel > 0)
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return (EPERM);
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KLD_LOCK_ASSERT();
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sx_assert(&kld_sx, SA_XLOCKED);
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KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
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/* Easy case of just dropping a reference. */
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@ -664,10 +657,10 @@ linker_file_unload(linker_file_t file, int flags)
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*/
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if (file->flags & LINKER_FILE_LINKED) {
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file->flags &= ~LINKER_FILE_LINKED;
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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linker_file_sysuninit(file);
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linker_file_unregister_sysctls(file);
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KLD_LOCK();
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sx_xlock(&kld_sx);
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}
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TAILQ_REMOVE(&linker_files, file, link);
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@ -706,7 +699,7 @@ linker_file_add_dependency(linker_file_t file, linker_file_t dep)
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{
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linker_file_t *newdeps;
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KLD_LOCK_ASSERT();
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sx_assert(&kld_sx, SA_XLOCKED);
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newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
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M_LINKER, M_WAITOK | M_ZERO);
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if (newdeps == NULL)
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@ -738,12 +731,12 @@ linker_file_lookup_set(linker_file_t file, const char *name,
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{
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int error, locked;
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locked = KLD_LOCKED();
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locked = sx_xlocked(&kld_sx);
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if (!locked)
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KLD_LOCK();
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sx_xlock(&kld_sx);
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error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
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if (!locked)
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (error);
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}
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@ -763,12 +756,12 @@ linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
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caddr_t sym;
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int locked;
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locked = KLD_LOCKED();
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locked = sx_xlocked(&kld_sx);
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if (!locked)
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KLD_LOCK();
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sx_xlock(&kld_sx);
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sym = linker_file_lookup_symbol_internal(file, name, deps);
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if (!locked)
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (sym);
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}
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@ -782,7 +775,7 @@ linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
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size_t common_size = 0;
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int i;
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KLD_LOCK_ASSERT();
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sx_assert(&kld_sx, SA_XLOCKED);
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KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
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file, name, deps));
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@ -982,9 +975,9 @@ linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
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{
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int error;
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KLD_LOCK();
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sx_xlock(&kld_sx);
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error = linker_debug_search_symbol_name(value, buf, buflen, offset);
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (error);
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}
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@ -1026,10 +1019,10 @@ kern_kldload(struct thread *td, const char *file, int *fileid)
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modname = file;
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}
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KLD_LOCK();
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sx_xlock(&kld_sx);
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error = linker_load_module(kldname, modname, NULL, NULL, &lf);
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if (error) {
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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goto done;
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}
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lf->userrefs++;
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@ -1039,13 +1032,13 @@ kern_kldload(struct thread *td, const char *file, int *fileid)
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EVENTHANDLER_INVOKE(kld_load, lf);
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#ifdef HWPMC_HOOKS
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KLD_DOWNGRADE();
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sx_downgrade(&kld_sx);
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pkm.pm_file = lf->filename;
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pkm.pm_address = (uintptr_t) lf->address;
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PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
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KLD_UNLOCK_READ();
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sx_sunlock(&kld_sx);
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#else
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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#endif
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done:
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@ -1088,7 +1081,7 @@ kern_kldunload(struct thread *td, int fileid, int flags)
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return (error);
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CURVNET_SET(TD_TO_VNET(td));
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KLD_LOCK();
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sx_xlock(&kld_sx);
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lf = linker_find_file_by_id(fileid);
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if (lf) {
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KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
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@ -1119,13 +1112,13 @@ kern_kldunload(struct thread *td, int fileid, int flags)
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#ifdef HWPMC_HOOKS
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if (error == 0) {
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KLD_DOWNGRADE();
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sx_downgrade(&kld_sx);
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PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
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KLD_UNLOCK_READ();
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sx_sunlock(&kld_sx);
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} else
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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#else
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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#endif
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CURVNET_RESTORE();
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return (error);
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@ -1169,13 +1162,13 @@ sys_kldfind(struct thread *td, struct kldfind_args *uap)
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goto out;
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filename = linker_basename(pathname);
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KLD_LOCK();
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sx_xlock(&kld_sx);
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lf = linker_find_file_by_name(filename);
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if (lf)
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td->td_retval[0] = lf->id;
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else
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error = ENOENT;
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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out:
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free(pathname, M_TEMP);
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return (error);
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@ -1193,7 +1186,7 @@ sys_kldnext(struct thread *td, struct kldnext_args *uap)
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return (error);
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#endif
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KLD_LOCK();
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sx_xlock(&kld_sx);
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if (uap->fileid == 0)
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lf = TAILQ_FIRST(&linker_files);
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else {
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@ -1214,7 +1207,7 @@ sys_kldnext(struct thread *td, struct kldnext_args *uap)
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else
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td->td_retval[0] = 0;
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out:
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (error);
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}
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@ -1253,10 +1246,10 @@ kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
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return (error);
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#endif
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KLD_LOCK();
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sx_xlock(&kld_sx);
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lf = linker_find_file_by_id(fileid);
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if (lf == NULL) {
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (ENOENT);
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}
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@ -1274,7 +1267,7 @@ kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
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if (namelen > MAXPATHLEN)
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namelen = MAXPATHLEN;
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bcopy(lf->pathname, &stat->pathname[0], namelen);
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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td->td_retval[0] = 0;
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return (0);
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@ -1293,7 +1286,7 @@ sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
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return (error);
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#endif
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KLD_LOCK();
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sx_xlock(&kld_sx);
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lf = linker_find_file_by_id(uap->fileid);
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if (lf) {
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MOD_SLOCK;
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@ -1305,7 +1298,7 @@ sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
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MOD_SUNLOCK;
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} else
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error = ENOENT;
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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return (error);
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}
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@ -1333,7 +1326,7 @@ sys_kldsym(struct thread *td, struct kldsym_args *uap)
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symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
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if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
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goto out;
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KLD_LOCK();
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sx_xlock(&kld_sx);
|
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if (uap->fileid != 0) {
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lf = linker_find_file_by_id(uap->fileid);
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if (lf == NULL)
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@ -1359,7 +1352,7 @@ sys_kldsym(struct thread *td, struct kldsym_args *uap)
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if (lf == NULL)
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error = ENOENT;
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}
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KLD_UNLOCK();
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sx_xunlock(&kld_sx);
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out:
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free(symstr, M_TEMP);
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return (error);
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@ -1468,6 +1461,7 @@ linker_preload(void *arg)
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error = 0;
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modptr = NULL;
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sx_xlock(&kld_sx);
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while ((modptr = preload_search_next_name(modptr)) != NULL) {
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modname = (char *)preload_search_info(modptr, MODINFO_NAME);
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modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
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@ -1649,6 +1643,7 @@ linker_preload(void *arg)
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TAILQ_REMOVE(&depended_files, lf, loaded);
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linker_file_unload(lf, LINKER_UNLOAD_FORCE);
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}
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sx_xunlock(&kld_sx);
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/* woohoo! we made it! */
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}
|
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@ -1948,7 +1943,7 @@ linker_hwpmc_list_objects(void)
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int i, nmappings;
|
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nmappings = 0;
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KLD_LOCK_READ();
|
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sx_slock(&kld_sx);
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TAILQ_FOREACH(lf, &linker_files, link)
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nmappings++;
|
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@ -1963,7 +1958,7 @@ linker_hwpmc_list_objects(void)
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kobase[i].pm_address = (uintptr_t)lf->address;
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i++;
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}
|
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KLD_UNLOCK_READ();
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sx_sunlock(&kld_sx);
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|
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KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
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|
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@ -1989,7 +1984,7 @@ linker_load_module(const char *kldname, const char *modname,
|
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char *pathname;
|
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int error;
|
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|
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KLD_LOCK_ASSERT();
|
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sx_assert(&kld_sx, SA_XLOCKED);
|
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if (modname == NULL) {
|
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/*
|
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* We have to load KLD
|
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@ -2063,7 +2058,7 @@ linker_load_dependencies(linker_file_t lf)
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/*
|
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* All files are dependant on /kernel.
|
||||
*/
|
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KLD_LOCK_ASSERT();
|
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sx_assert(&kld_sx, SA_XLOCKED);
|
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if (linker_kernel_file) {
|
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linker_kernel_file->refs++;
|
||||
error = linker_file_add_dependency(lf, linker_kernel_file);
|
||||
@ -2155,16 +2150,16 @@ sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
|
||||
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));
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user