powerpc/64: Init jump labels before parse_early_param()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: 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(). [mpe: Add call trace to change log and minor wording edits.]

References

• https://git.kernel.org/stable/c/e3c9e9452a8ea12d335b1e59b2c72e1b99c699b8
• https://git.kernel.org/stable/c/8f9357313cdcadb0a311b44c29d4eaccc7fa632f
• https://git.kernel.org/stable/c/ca829e05d3d4f728810cc5e4b468d9ebc7745eb3