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authorKees Cook <keescook@chromium.org>2018-11-30 14:36:58 -0800
committerKees Cook <keescook@chromium.org>2018-12-03 17:11:02 -0800
commitea84b580b95521644429cc6748b6c2bf27c8b0f3 (patch)
tree85cffd2d9d61cd2ee0fe379384f9f2fe12292598 /drivers/firmware
parent69596433bc28a4642bdc84676f44cfa3b16d0588 (diff)
pstore: Convert buf_lock to semaphore
Instead of running with interrupts disabled, use a semaphore. This should make it easier for backends that may need to sleep (e.g. EFI) when performing a write: |BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 |in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum |Preemption disabled at: |[<ffffffff99d60512>] pstore_dump+0x72/0x330 |CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G D 4.20.0-rc3 #45 |Call Trace: | dump_stack+0x4f/0x6a | ___might_sleep.cold.91+0xd3/0xe4 | __might_sleep+0x50/0x90 | wait_for_completion+0x32/0x130 | virt_efi_query_variable_info+0x14e/0x160 | efi_query_variable_store+0x51/0x1a0 | efivar_entry_set_safe+0xa3/0x1b0 | efi_pstore_write+0x109/0x140 | pstore_dump+0x11c/0x330 | kmsg_dump+0xa4/0xd0 | oops_exit+0x22/0x30 ... Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Fixes: 21b3ddd39fee ("efi: Don't use spinlocks for efi vars") Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/efi-pstore.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index cfe87b465819..0f7d97917197 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -259,8 +259,7 @@ static int efi_pstore_write(struct pstore_record *record)
efi_name[i] = name[i];
ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
- !pstore_cannot_block_path(record->reason),
- record->size, record->psi->buf);
+ preemptible(), record->size, record->psi->buf);
if (record->reason == KMSG_DUMP_OOPS)
efivar_run_worker();
@@ -369,7 +368,6 @@ static __init int efivars_pstore_init(void)
return -ENOMEM;
efi_pstore_info.bufsize = 1024;
- spin_lock_init(&efi_pstore_info.buf_lock);
if (pstore_register(&efi_pstore_info)) {
kfree(efi_pstore_info.buf);