On Thu, Sep 01, 2016 at 05:30:13PM +0100, James Hogan wrote:
> Update arch_uprobe_copy_ixol() to use the kmap_atomic() based kernel
> address to flush the icache with flush_icache_range(), rather than the
> user mapping. We have the kernel mapping available anyway and this
> avoids having to switch to using the new __flush_icache_user_range() for
> the sake of Enhanced Virtual Addressing (EVA) where flush_icache_range()
> will become ineffective on user addresses.
>
> Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Cc: Leonid Yegoshin <leonid.yegoshin@xxxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxx
> ---
> arch/mips/kernel/uprobes.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/arch/mips/kernel/uprobes.c b/arch/mips/kernel/uprobes.c
> index 8452d933a645..9a507ab1ea38 100644
> --- a/arch/mips/kernel/uprobes.c
> +++ b/arch/mips/kernel/uprobes.c
> @@ -301,19 +301,14 @@ int set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
> void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
> void *src, unsigned long len)
> {
> - void *kaddr;
> + void *kaddr, kstart;
>
> /* Initialize the slot */
> kaddr = kmap_atomic(page);
> - memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);
> + kstart = kaddr + (vaddr & ~PAGE_MASK);
> + memcpy(kstart, src, len);
> + flush_icache_range(kstart, kstart + len);
> kunmap_atomic(kaddr);
> -
> - /*
> - * The MIPS version of flush_icache_range will operate safely on
> - * user space addresses and more importantly, it doesn't require a
> - * VMA argument.
> - */
> - flush_icache_range(vaddr, vaddr + len);
I can't convince myself this is right wrt. to cache aliases ...
Ralf
