On Fri, Aug 14, 2020 at 07:27:14PM +0200, Andrey Konovalov wrote: > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index c62c8ba85c0e..cf00b3942564 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -14,6 +14,7 @@ > #include <linux/mm.h> > #include <linux/hardirq.h> > #include <linux/init.h> > +#include <linux/kasan.h> > #include <linux/kprobes.h> > #include <linux/uaccess.h> > #include <linux/page-flags.h> > @@ -314,11 +315,19 @@ static void report_tag_fault(unsigned long addr, > unsigned int esr, > { > bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0; > > +#ifdef CONFIG_KASAN_HW_TAGS > + /* > + * SAS bits aren't set for all faults reported in EL1, so we can't > + * find out access size. > + */ > + kasan_report(addr, 0, is_write, regs->pc); > +#else > pr_alert("Memory Tagging Extension Fault in %pS\n", (void *)regs->pc); > pr_alert(" %s at address %lx\n", is_write ? "Write" : "Read", addr); > pr_alert(" Pointer tag: [%02x], memory tag: [%02x]\n", > mte_get_ptr_tag(addr), > mte_get_mem_tag((void *)addr)); > +#endif > }
More dead code. So what's the point of keeping the pr_alert() introduced earlier? CONFIG_KASAN_HW_TAGS is always on for in-kernel MTE. If MTE is disabled, this function isn't called anyway. -- Catalin