On Wed, 16 Dec 2020 10:42:09 +0100 SeongJae Park <[email protected]> wrote:
> From: SeongJae Park <[email protected]> > > Some 'damon-dbgfs' users would want to monitor only a part of the entire > virtual memory address space. The framework users in the kernel space > could use '->init_target_regions' callback or even set the regions > inside the context struct as they want, but 'damon-dbgfs' users cannot. > > For the reason, this commit introduces a new debugfs file, > 'init_region'. 'damon-dbgfs' users can specify which initial monitoring > target address regions they want by writing special input to the file. > The input should describe each region in each line in below form: > > <pid> <start address> <end address> > > Note that the regions will be updated to cover entire memory mapped > regions after 'regions update interval'. If you want the regions to not > be updated after the initial setting, you could set the interval as a > very long time, say, a few decades. > > Signed-off-by: SeongJae Park <[email protected]> > --- > mm/damon/dbgfs.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 151 insertions(+), 3 deletions(-) > > diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c > index 06295c986dc3..2f1ec6ebd9f0 100644 > --- a/mm/damon/dbgfs.c > +++ b/mm/damon/dbgfs.c [...] > + > +static ssize_t dbgfs_init_regions_read(struct file *file, char __user *buf, > + size_t count, loff_t *ppos) > +{ > + struct damon_ctx *ctx = file->private_data; > + char *kbuf; > + ssize_t len; > + > + kbuf = kmalloc(count, GFP_KERNEL); > + if (!kbuf) > + return -ENOMEM; > + > + mutex_lock(&ctx->kdamond_lock); > + if (ctx->kdamond) { > + mutex_unlock(&ctx->kdamond_lock); > + return -EBUSY; Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc. found that above return is missing deallocation of 'kbuf'. I will fix this in the next version. > + } > + > + len = sprint_init_regions(ctx, kbuf, count); > + mutex_unlock(&ctx->kdamond_lock); > + if (len < 0) > + goto out; > + len = simple_read_from_buffer(buf, count, ppos, kbuf, len); > + > +out: > + kfree(kbuf); > + return len; > +} Thanks, SeongJae Park [...]
