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| author | Prarit Bhargava <prarit@redhat.com> | 2019-05-29 13:26:25 +0200 |
|---|---|---|
| committer | Jessica Yu <jeyu@kernel.org> | 2019-06-05 09:53:24 +0200 |
| commit | 6e6de3dee51a439f76eb73c22ae2ffd2c9384712 (patch) | |
| tree | 8ab6a8fa8c082d4e981cb7f9572ec7d0f6462640 /kernel | |
| parent | Linux 5.2-rc2 (diff) | |
| download | linux-6e6de3dee51a439f76eb73c22ae2ffd2c9384712.tar.xz linux-6e6de3dee51a439f76eb73c22ae2ffd2c9384712.zip | |
kernel/module.c: Only return -EEXIST for modules that have finished loading
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>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/module.c | 6 |
1 files 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 @@ again: 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, |