Author: markj
Date: Sat Aug 24 21:08:55 2013
New Revision: 254811
URL: http://svnweb.freebsd.org/changeset/base/254811
Log:
Set things up so that linker_file_lookup_set() is always called with the
linker lock held. This makes it possible to call it from a kld event handler
with the shared lock held.
Reviewed by: jhb
Modified:
head/sys/kern/kern_linker.c
Modified: head/sys/kern/kern_linker.c
==============================================================================
--- head/sys/kern/kern_linker.c Sat Aug 24 21:07:04 2013 (r254810)
+++ head/sys/kern/kern_linker.c Sat Aug 24 21:08:55 2013 (r254811)
@@ -188,6 +188,8 @@ linker_file_sysinit(linker_file_t lf)
KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
lf->filename));
+ sx_assert(&kld_sx, SA_XLOCKED);
+
if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
return;
/*
@@ -213,6 +215,7 @@ linker_file_sysinit(linker_file_t lf)
* Traverse the (now) ordered list of system initialization tasks.
* Perform each task, and continue on to the next task.
*/
+ sx_xunlock(&kld_sx);
mtx_lock(&Giant);
for (sipp = start; sipp < stop; sipp++) {
if ((*sipp)->subsystem == SI_SUB_DUMMY)
@@ -222,6 +225,7 @@ linker_file_sysinit(linker_file_t lf)
(*((*sipp)->func)) ((*sipp)->udata);
}
mtx_unlock(&Giant);
+ sx_xlock(&kld_sx);
}
static void
@@ -232,6 +236,8 @@ linker_file_sysuninit(linker_file_t lf)
KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
lf->filename));
+ sx_assert(&kld_sx, SA_XLOCKED);
+
if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
NULL) != 0)
return;
@@ -259,6 +265,7 @@ linker_file_sysuninit(linker_file_t lf)
* Traverse the (now) ordered list of system initialization tasks.
* Perform each task, and continue on to the next task.
*/
+ sx_xunlock(&kld_sx);
mtx_lock(&Giant);
for (sipp = start; sipp < stop; sipp++) {
if ((*sipp)->subsystem == SI_SUB_DUMMY)
@@ -268,6 +275,7 @@ linker_file_sysuninit(linker_file_t lf)
(*((*sipp)->func)) ((*sipp)->udata);
}
mtx_unlock(&Giant);
+ sx_xlock(&kld_sx);
}
static void
@@ -279,13 +287,17 @@ linker_file_register_sysctls(linker_file
("linker_file_register_sysctls: registering SYSCTLs for %s\n",
lf->filename));
+ sx_assert(&kld_sx, SA_XLOCKED);
+
if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
return;
+ sx_xunlock(&kld_sx);
sysctl_lock();
for (oidp = start; oidp < stop; oidp++)
sysctl_register_oid(*oidp);
sysctl_unlock();
+ sx_xlock(&kld_sx);
}
static void
@@ -296,13 +308,17 @@ linker_file_unregister_sysctls(linker_fi
KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
" for %s\n", lf->filename));
+ sx_assert(&kld_sx, SA_XLOCKED);
+
if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
return;
+ sx_xunlock(&kld_sx);
sysctl_lock();
for (oidp = start; oidp < stop; oidp++)
sysctl_unregister_oid(*oidp);
sysctl_unlock();
+ sx_xlock(&kld_sx);
}
static int
@@ -315,6 +331,8 @@ linker_file_register_modules(linker_file
KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
" in %s\n", lf->filename));
+ sx_assert(&kld_sx, SA_XLOCKED);
+
if (linker_file_lookup_set(lf, "modmetadata_set", &start,
&stop, NULL) != 0) {
/*
@@ -403,10 +421,8 @@ linker_load_file(const char *filename, l
return (error);
}
modules = !TAILQ_EMPTY(&lf->modules);
- sx_xunlock(&kld_sx);
linker_file_register_sysctls(lf);
linker_file_sysinit(lf);
- sx_xlock(&kld_sx);
lf->flags |= LINKER_FILE_LINKED;
/*
@@ -657,10 +673,8 @@ linker_file_unload(linker_file_t file, i
*/
if (file->flags & LINKER_FILE_LINKED) {
file->flags &= ~LINKER_FILE_LINKED;
- sx_xunlock(&kld_sx);
linker_file_sysuninit(file);
linker_file_unregister_sysctls(file);
- sx_xlock(&kld_sx);
}
TAILQ_REMOVE(&linker_files, file, link);
@@ -729,15 +743,9 @@ int
linker_file_lookup_set(linker_file_t file, const char *name,
void *firstp, void *lastp, int *countp)
{
- int error, locked;
- locked = sx_xlocked(&kld_sx);
- if (!locked)
- sx_xlock(&kld_sx);
- error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
- if (!locked)
- sx_xunlock(&kld_sx);
- return (error);
+ sx_assert(&kld_sx, SA_LOCKED);
+ return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
}
/*
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