diff options
Diffstat (limited to 'arch/powerpc/kernel/setup_64.c')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index e05e6dd67ae6..438a9befce41 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -279,24 +279,42 @@ void __init record_spr_defaults(void) * device-tree is not accessible via normal means at this point. */ -void __init early_setup(unsigned long dt_ptr) +void __init __nostackprotector early_setup(unsigned long dt_ptr) { static __initdata struct paca_struct boot_paca; /* -------- printk is _NOT_ safe to use here ! ------- */ - /* Try new device tree based feature discovery ... */ - if (!dt_cpu_ftrs_init(__va(dt_ptr))) - /* Otherwise use the old style CPU table */ - identify_cpu(0, mfspr(SPRN_PVR)); - - /* Assume we're on cpu 0 for now. Don't write to the paca yet! */ + /* + * Assume we're on cpu 0 for now. + * + * We need to load a PACA very early for a few reasons. + * + * The stack protector canary is stored in the paca, so as soon as we + * call any stack protected code we need r13 pointing somewhere valid. + * + * If we are using kcov it will call in_task() in its instrumentation, + * which relies on the current task from the PACA. + * + * dt_cpu_ftrs_init() calls into generic OF/fdt code, as well as + * printk(), which can trigger both stack protector and kcov. + * + * percpu variables and spin locks also use the paca. + * + * So set up a temporary paca. It will be replaced below once we know + * what CPU we are on. + */ initialise_paca(&boot_paca, 0); setup_paca(&boot_paca); fixup_boot_paca(); /* -------- printk is now safe to use ------- */ + /* Try new device tree based feature discovery ... */ + if (!dt_cpu_ftrs_init(__va(dt_ptr))) + /* Otherwise use the old style CPU table */ + identify_cpu(0, mfspr(SPRN_PVR)); + /* Enable early debugging if any specified (see udbg.h) */ udbg_early_init(); |