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authorZhouyi Zhou2022-07-26 09:57:47 +0800
committerMichael Ellerman2022-08-01 22:21:19 +1000
commitca829e05d3d4f728810cc5e4b468d9ebc7745eb3 (patch)
treedfdf8b2d4ba602ee9d010b868cb3f4bae9e0f111
parentff446cd76854d47f451a84c26bb70934ae2ec5a7 (diff)
powerpc/64: Init jump labels before parse_early_param()
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
-rw-r--r--arch/powerpc/kernel/prom.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 0a68c99da573..a730b951b64b 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -752,6 +752,13 @@ void __init early_init_devtree(void *params)
early_init_dt_scan_root();
early_init_dt_scan_memory_ppc();
+ /*
+ * 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 */