svn commit: r284153 - head/sys/kern
John Baldwin
jhb at freebsd.org
Mon Jun 8 18:30:09 UTC 2015
On Monday, June 08, 2015 03:46:29 PM Ruslan Bukin wrote:
> For some reason it hangs for me after 'random' lines on arm64
Are you using dtrace? It looks like sdt was using the public symbol before
but in a context where the caller held the lock. I will revert this for now.
I think I can perhaps make it 'automatic' by having it acquire a read lock
(possibly recursing) if it doesn't already hold a write lock.
> FreeBSD clang version 3.6.1 (tags/RELEASE_361/final 237755) 20150525
> CPU: ARM Cortex-A57 r1p0
> IMPLEMENT ME: dtrace_toxic_ranges
> random: entropy device infrastructure driver
> random: selecting highest priority adaptor <Dummy>
>
> On Mon, Jun 08, 2015 at 02:06:48PM +0000, John Baldwin wrote:
> > Author: jhb
> > Date: Mon Jun 8 14:06:47 2015
> > New Revision: 284153
> > URL: https://svnweb.freebsd.org/changeset/base/284153
> >
> > Log:
> > Add an internal "locked" variant of linker_file_lookup_set() and change
> > the public function to acquire the global linker lock directly. This
> > permits linker_file_lookup_set() to be safely used from other modules.
> >
> > Modified:
> > head/sys/kern/kern_linker.c
> >
> > Modified: head/sys/kern/kern_linker.c
> > ==============================================================================
> > --- head/sys/kern/kern_linker.c Mon Jun 8 13:23:56 2015 (r284152)
> > +++ head/sys/kern/kern_linker.c Mon Jun 8 14:06:47 2015 (r284153)
> > @@ -137,6 +137,8 @@ static int linker_file_add_dependency(li
> > linker_file_t dep);
> > static caddr_t linker_file_lookup_symbol_internal(linker_file_t file,
> > const char* name, int deps);
> > +static int linker_file_lookup_set_locked(linker_file_t file,
> > + const char *name, void *firstp, void *lastp, int *countp);
> > static int linker_load_module(const char *kldname,
> > const char *modname, struct linker_file *parent,
> > const struct mod_depend *verinfo, struct linker_file **lfpp);
> > @@ -189,7 +191,8 @@ linker_file_sysinit(linker_file_t lf)
> >
> > sx_assert(&kld_sx, SA_XLOCKED);
> >
> > - if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
> > + if (linker_file_lookup_set_locked(lf, "sysinit_set", &start, &stop,
> > + NULL) != 0)
> > return;
> > /*
> > * Perform a bubble sort of the system initialization objects by
> > @@ -237,7 +240,7 @@ linker_file_sysuninit(linker_file_t lf)
> >
> > sx_assert(&kld_sx, SA_XLOCKED);
> >
> > - if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
> > + if (linker_file_lookup_set_locked(lf, "sysuninit_set", &start, &stop,
> > NULL) != 0)
> > return;
> >
> > @@ -288,7 +291,8 @@ linker_file_register_sysctls(linker_file
> >
> > sx_assert(&kld_sx, SA_XLOCKED);
> >
> > - if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
> > + if (linker_file_lookup_set_locked(lf, "sysctl_set", &start, &stop,
> > + NULL) != 0)
> > return;
> >
> > sx_xunlock(&kld_sx);
> > @@ -309,7 +313,8 @@ linker_file_unregister_sysctls(linker_fi
> >
> > sx_assert(&kld_sx, SA_XLOCKED);
> >
> > - if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
> > + if (linker_file_lookup_set_locked(lf, "sysctl_set", &start, &stop,
> > + NULL) != 0)
> > return;
> >
> > sx_xunlock(&kld_sx);
> > @@ -332,7 +337,7 @@ linker_file_register_modules(linker_file
> >
> > sx_assert(&kld_sx, SA_XLOCKED);
> >
> > - if (linker_file_lookup_set(lf, "modmetadata_set", &start,
> > + if (linker_file_lookup_set_locked(lf, "modmetadata_set", &start,
> > &stop, NULL) != 0) {
> > /*
> > * This fallback should be unnecessary, but if we get booted
> > @@ -742,8 +747,8 @@ linker_file_add_dependency(linker_file_t
> > * This function is used in this file so we can avoid having lots of (void **)
> > * casts.
> > */
> > -int
> > -linker_file_lookup_set(linker_file_t file, const char *name,
> > +static int
> > +linker_file_lookup_set_locked(linker_file_t file, const char *name,
> > void *firstp, void *lastp, int *countp)
> > {
> >
> > @@ -751,6 +756,19 @@ linker_file_lookup_set(linker_file_t fil
> > return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
> > }
> >
> > +int
> > +linker_file_lookup_set(linker_file_t file, const char *name,
> > + void *firstp, void *lastp, int *countp)
> > +{
> > + int error;
> > +
> > + sx_slock(&kld_sx);
> > + error = linker_file_lookup_set_locked(file, name, firstp, lastp,
> > + countp);
> > + sx_sunlock(&kld_sx);
> > + return (error);
> > +}
> > +
> > /*
> > * List all functions in a file.
> > */
> > @@ -1469,8 +1487,8 @@ linker_preload(void *arg)
> > /*
> > * First get a list of stuff in the kernel.
> > */
> > - if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
> > - &stop, NULL) == 0)
> > + if (linker_file_lookup_set_locked(linker_kernel_file, MDT_SETNAME,
> > + &start, &stop, NULL) == 0)
> > linker_addmodules(linker_kernel_file, start, stop, 1);
> >
> > /*
> > @@ -1479,7 +1497,7 @@ linker_preload(void *arg)
> > */
> > restart:
> > TAILQ_FOREACH(lf, &loaded_files, loaded) {
> > - error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
> > + error = linker_file_lookup_set_locked(lf, MDT_SETNAME, &start,
> > &stop, NULL);
> > /*
> > * First, look to see if we would successfully link with this
> > @@ -1573,7 +1591,7 @@ restart:
> > panic("cannot add dependency");
> > }
> > lf->userrefs++; /* so we can (try to) kldunload it */
> > - error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
> > + error = linker_file_lookup_set_locked(lf, MDT_SETNAME, &start,
> > &stop, NULL);
> > if (!error) {
> > for (mdp = start; mdp < stop; mdp++) {
> > @@ -1610,7 +1628,7 @@ restart:
> > goto fail;
> > }
> > linker_file_register_modules(lf);
> > - if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
> > + if (linker_file_lookup_set_locked(lf, "sysinit_set", &si_start,
> > &si_stop, NULL) == 0)
> > sysinit_add(si_start, si_stop);
> > linker_file_register_sysctls(lf);
> > @@ -2042,7 +2060,7 @@ linker_load_dependencies(linker_file_t l
> > if (error)
> > return (error);
> > }
> > - if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
> > + if (linker_file_lookup_set_locked(lf, MDT_SETNAME, &start, &stop,
> > &count) != 0)
> > return (0);
> > for (mdp = start; mdp < stop; mdp++) {
> >
>
--
John Baldwin
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