When doing
echo 1 > /sys/devices/system/cpu/microcode/reload
in order to reload microcode, I get:
microcode: Total microcode saved: 1
BUG: using smp_processor_id() in preemptible [00000000] code: bash/2606
caller is debug_smp_processor_id+0x17/0x20
CPU: 1 PID: 2606 Comm: bash Not tainted 3.19.0-rc7+ #9
Hardware name: LENOVO 2320CTO/2320CTO, BIOS G2ET86WW (2.06 ) 11/13/2012
ffffffff81a4266d ffff8802131db808 ffffffff81666588 0000000000000007
0000000000000001 ffff8802131db838 ffffffff812e6eef ffff8802131db868
00000000000306a9 0000000000000010 0000000000000015 ffff8802131db848
Call Trace:
dump_stack
check_preemption_disabled
debug_smp_processor_id
show_saved_mc
? save_microcode.constprop.8
save_mc_for_early
? print_context_stack
? dump_trace
? __bfs
? mark_held_locks
? get_page_from_freelist
? trace_hardirqs_on_caller
? trace_hardirqs_on
? __alloc_pages_nodemask
? __get_vm_area_node
? map_vm_area
? __vmalloc_node_range
? generic_load_microcode
generic_load_microcode
? microcode_fini_cpu
request_microcode_fw
reload_store
dev_attr_store
sysfs_kf_write
kernfs_fop_write
vfs_write
? sysret_check
SyS_write
system_call_fastpath
microcode: CPU1: sig=0x306a9, pf=0x10, rev=0x15
microcode: mc_saved[0]: sig=0x306a9, pf=0x12, rev=0x1b, toal size=0x3000, date = 2014-05-29
because we're using smp_processor_id() in preemtible context. And we
don't really need to use it there because the microcode container we're
dumping is global and CPU-specific info is irrelevant.
While at it, make pr_* stuff use "microcode: " prefix for easier
grepping and document how to enable the DEBUG build.
Signed-off-by: Borislav Petkov <bp@suse.de>
a858b5e504