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
