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| author |   Zhouyi Zhou <zhouzhouyi@gmail.com> | 2022-07-26 09:57:47 +0800 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-08-01 22:21:19 +1000 |
| commit | ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 (patch) | |
| tree | dfdf8b2d4ba602ee9d010b868cb3f4bae9e0f111 /arch/powerpc/kernel/prom.c | |
| parent | selftests/powerpc: Avoid GCC 12 uninitialised variable warning (diff) | |
| download | linux-dev-ca829e05d3d4f728810cc5e4b468d9ebc7745eb3.tar.xz linux-dev-ca829e05d3d4f728810cc5e4b468d9ebc7745eb3.zip | |
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
Diffstat (limited to 'arch/powerpc/kernel/prom.c')
| -rw-r--r-- | arch/powerpc/kernel/prom.c | 7 |
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 */ |