Messages in this thread Patch in this message | | | Date | Tue, 4 Jun 2019 16:29:31 +0200 | From | Jessica Yu <> | Subject | Re: [PATCH v3] kernel/module.c: Only return -EEXIST for modules that have finished loading |
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+++ Prarit Bhargava [29/05/19 07:26 -0400]: >Microsoft HyperV disables the X86_FEATURE_SMCA bit on AMD systems, and >linux guests boot with repeated errors: > >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@redhat.com> >Signed-off-by: Barret Rhoden <brho@google.com> >Cc: David Arcari <darcari@redhat.com> >Cc: Jessica Yu <jeyu@kernel.org> >Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Applied. Thanks!
Jessica
>--- > kernel/module.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > >diff --git a/kernel/module.c b/kernel/module.c >index 6e6712b3aaf5..1e7dcbe527af 100644 >--- a/kernel/module.c >+++ b/kernel/module.c >@@ -3397,8 +3397,7 @@ 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; >@@ -3588,8 +3587,7 @@ 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, >-- >2.21.0 >
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