* Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> wrote:
> This patchset implements Uprobes which enables you to
> dynamically probe any routine in a user space application and
> collect information non-disruptively.
Did all review feedback get addressed in your latest tree?
If yes then it would be nice to hear the opinion of Andrew about
this bit:
> mm/mmap.c | 33 +-
The relevant portion of the patch is:
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -30,6 +30,7 @@
> #include <linux/perf_event.h>
> #include <linux/audit.h>
> #include <linux/khugepaged.h>
> +#include <linux/uprobes.h>
>
> #include <asm/uaccess.h>
> #include <asm/cacheflush.h>
> @@ -616,6 +617,13 @@ again: remove_next = 1 + (end > next->vm_end);
> if (mapping)
> mutex_unlock(&mapping->i_mmap_mutex);
>
> + if (root) {
> + mmap_uprobe(vma);
> +
> + if (adjust_next)
> + mmap_uprobe(next);
> + }
> +
> if (remove_next) {
> if (file) {
> fput(file);
> @@ -637,6 +645,8 @@ again: remove_next = 1 + (end > next->vm_end);
> goto again;
> }
> }
> + if (insert && file)
> + mmap_uprobe(insert);
>
> validate_mm(mm);
>
> @@ -1329,6 +1339,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> mm->locked_vm += (len >> PAGE_SHIFT);
> } else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
> make_pages_present(addr, addr + len);
> +
> + if (file && mmap_uprobe(vma))
> + /* matching probes but cannot insert */
> + goto unmap_and_free_vma;
> +
> return addr;
>
> unmap_and_free_vma:
> @@ -2305,6 +2320,10 @@ int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma)
> if ((vma->vm_flags & VM_ACCOUNT) &&
> security_vm_enough_memory_mm(mm, vma_pages(vma)))
> return -ENOMEM;
> +
> + if (vma->vm_file && mmap_uprobe(vma))
> + return -EINVAL;
> +
> vma_link(mm, vma, prev, rb_link, rb_parent);
> return 0;
> }
> @@ -2356,6 +2375,10 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
> new_vma->vm_pgoff = pgoff;
> if (new_vma->vm_file) {
> get_file(new_vma->vm_file);
> +
> + if (mmap_uprobe(new_vma))
> + goto out_free_mempol;
> +
> if (vma->vm_flags & VM_EXECUTABLE)
> added_exe_file_vma(mm);
> }
it's named mmap_uprobe(), which makes it rather single-purpose.
The uprobes code wants to track vma life-time so that it can
manage uprobes breakpoints installed here, correct?
We already have some other vma tracking goodies in perf itself
(see perf_event_mmap() et al) - would it make sense to merge the
two vma instrumentation facilities and not burden mm/ with two
separate sets of callbacks?
If all such issues are resolved then i guess we could queue up
uprobes in -tip, conditional on it remaining sufficiently
regression-, problem- and NAK-free.
Also, it would be nice to hear Arnaldo's opinion about the
tools/perf/ bits.
Thanks,
Ingo
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>