Le 07/07/2023 à 03:31, Benjamin Gray a écrit : > The KCOV handler __sanitizer_cov_trace_pc() uses the PACA, so initialise > the PACA first. This fixes a hang during boot when KASAN and KCOV are > both enabled, where the coverage tracer in kasan_early_init() tries to > access a field of the (currently null) PACA.
mm/kasan/Makefile has KCOV_INSTRUMENT := n Should we add the same in arch/powerpc/mm/kasan/Makefile to be consistent ? > > Signed-off-by: Benjamin Gray <bg...@linux.ibm.com> > > --- > > I tried annotating kasan_early_init() with 'notrace', but it still > seemed to hang. It would also be less robust, because kasan_early_init() > may in future call generic code that should keep coverage. > --- > arch/powerpc/kernel/head_64.S | 3 --- > arch/powerpc/kernel/setup_64.c | 4 ++++ > 2 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S > index f132d8704263..21a78a849ca8 100644 > --- a/arch/powerpc/kernel/head_64.S > +++ b/arch/powerpc/kernel/head_64.S > @@ -1004,9 +1004,6 @@ start_here_multiplatform: > * and SLB setup before we turn on relocation. > */ > > -#ifdef CONFIG_KASAN > - bl CFUNC(kasan_early_init) > -#endif > /* Restore parameters passed from prom_init/kexec */ > mr r3,r31 > LOAD_REG_ADDR(r12, DOTSYM(early_setup)) > diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c > index 246201d0d879..a3f5decbc041 100644 > --- a/arch/powerpc/kernel/setup_64.c > +++ b/arch/powerpc/kernel/setup_64.c > @@ -369,6 +369,10 @@ void __init early_setup(unsigned long dt_ptr) > > /* -------- printk is now safe to use ------- */ > > +#ifdef CONFIG_KASAN > + kasan_early_init(); > +#endif Don't #ifdef In arch/powerpc/include/asm/kasan.h add a stub for kasan_early_init() just like already done for kasan_init(), kasan_mmu_init() and kasan_late_init(). > + > if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && (mfmsr() & MSR_HV)) > enable_machine_check(); >
