From: Zhouyi Zhou zhouzhouyi@gmail.com
[ Upstream commit ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 ]
On 64-bit, calling jump_label_init() in setup_feature_keys() is too late because static keys may be used in subroutines of parse_early_param() which is again subroutine of early_init_devtree().
For example booting with "threadirqs":
static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init() WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120 ... NIP static_key_enable_cpuslocked+0xfc/0x120 LR static_key_enable_cpuslocked+0xf8/0x120 Call Trace: static_key_enable_cpuslocked+0xf8/0x120 (unreliable) static_key_enable+0x30/0x50 setup_forced_irqthreads+0x28/0x40 do_early_param+0xa0/0x108 parse_args+0x290/0x4e0 parse_early_options+0x48/0x5c parse_early_param+0x58/0x84 early_init_devtree+0xd4/0x518 early_setup+0xb4/0x214
So call jump_label_init() just before parse_early_param() in early_init_devtree().
Suggested-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Zhouyi Zhou zhouzhouyi@gmail.com [mpe: Add call trace to change log and minor wording edits.] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/prom.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index f8c49e5d4bd3..c57aeb9f031c 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -737,6 +737,13 @@ void __init early_init_devtree(void *params) of_scan_flat_dt(early_init_dt_scan_root, NULL); of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
+ /* + * As generic code authors expect to be able to use static keys + * in early_param() handlers, we initialize the static keys just + * before parsing early params (it's fine to call jump_label_init() + * more than once). + */ + jump_label_init(); parse_early_param();
/* make sure we've parsed cmdline for mem= before this */