Style comment below....
> From: Mike Frysinger <vapier....@gmail.com>
>
> When working with FDPIC, there are many shared mappings of read-only code
> regions between applications (the C library, applet packages like busybox,
> etc.), but the current do_mmap_pgoff() function will issue an icache flush
> whenever a VMA is added to an MM instead of only doing it when the map is
> initially created.
[...]
> Signed-off-by: David Howells <dhowe...@redhat.com>
> ---
[...]
> diff --git a/mm/nommu.c b/mm/nommu.c
> index 1544a65..bffbdfc 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -432,6 +432,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
> /*
> * Ok, looks good - let it rip.
> */
> + flush_icache_range(mm->brk, brk);
> return mm->brk = brk;
> }
>
> @@ -1354,10 +1355,14 @@ unsigned long do_mmap_pgoff(struct file *file,
> share:
> add_vma_to_mm(current->mm, vma);
>
> - up_write(&nommu_region_sem);
> + /* we flush the region from the icache only when the first executable
> + * mapping of it is made */
> + if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) {
As a "style pointer", would you please put parens around your
bit masking.... It would make me feel better. :)
if ((vma->vm_flags & VM_EXEC) && ...
Similar comment for part 4.
Thanks for all your work on this!!
all the best,
*brianW
> + flush_icache_range(region->vm_start, region->vm_end);
> + region->vm_icache_flushed = true;
> + }
>
> - if (prot & PROT_EXEC)
> - flush_icache_range(result, result + len);
> + up_write(&nommu_region_sem);
>
> kleave(" = %lx", result);
> return result;
>
> _______________________________________________
> uClinux-dev mailing list
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