On 7/26/19 9:38 AM, Sasha Levin wrote: > From: Prarit Bhargava <prarit@xxxxxxxxxx> > > [ Upstream commit 6e6de3dee51a439f76eb73c22ae2ffd2c9384712 ] > > Microsoft HyperV disables the X86_FEATURE_SMCA bit on AMD systems, and > linux guests boot with repeated errors: > Hey Sasha, I'd prefer to leave this out of stable branches for now. Linus is a bit nervous about it and I like to get see more soak time before the patch is backported to stable. https://lkml.org/lkml/2019/7/18/680 FWIW we've been running this in RHEL for some time now without any issues. P. > amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2) > amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2) > amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2) > amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2) > amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2) > amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2) > > The warnings occur because the module code erroneously returns -EEXIST > for modules that have failed to load and are in the process of being > removed from the module list. > > module amd64_edac_mod has a dependency on module edac_mce_amd. Using > modules.dep, systemd will load edac_mce_amd for every request of > amd64_edac_mod. When the edac_mce_amd module loads, the module has > state MODULE_STATE_UNFORMED and once the module load fails and the state > becomes MODULE_STATE_GOING. Another request for edac_mce_amd module > executes and add_unformed_module() will erroneously return -EEXIST even > though the previous instance of edac_mce_amd has MODULE_STATE_GOING. > Upon receiving -EEXIST, systemd attempts to load amd64_edac_mod, which > fails because of unknown symbols from edac_mce_amd. > > add_unformed_module() must wait to return for any case other than > MODULE_STATE_LIVE to prevent a race between multiple loads of > dependent modules. > > Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx> > Signed-off-by: Barret Rhoden <brho@xxxxxxxxxx> > Cc: David Arcari <darcari@xxxxxxxxxx> > Cc: Jessica Yu <jeyu@xxxxxxxxxx> > Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> > Signed-off-by: Jessica Yu <jeyu@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > kernel/module.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/kernel/module.c b/kernel/module.c > index 80c7c09584cf..8431c3d47c97 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -3385,8 +3385,7 @@ static bool finished_loading(const char *name) > sched_annotate_sleep(); > mutex_lock(&module_mutex); > mod = find_module_all(name, strlen(name), true); > - ret = !mod || mod->state == MODULE_STATE_LIVE > - || mod->state == MODULE_STATE_GOING; > + ret = !mod || mod->state == MODULE_STATE_LIVE; > mutex_unlock(&module_mutex); > > return ret; > @@ -3576,8 +3575,7 @@ static int add_unformed_module(struct module *mod) > mutex_lock(&module_mutex); > old = find_module_all(mod->name, strlen(mod->name), true); > if (old != NULL) { > - if (old->state == MODULE_STATE_COMING > - || old->state == MODULE_STATE_UNFORMED) { > + if (old->state != MODULE_STATE_LIVE) { > /* Wait in case it fails to load. */ > mutex_unlock(&module_mutex); > err = wait_event_interruptible(module_wq, >
