From: SeongJae Park sj@kernel.org
mainline inclusion from mainline-5.16 commit c026291ab88f02247999959d01182cb8eb6e6a5b category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4GVMK CVE: NA
------------------------------------------------- This makes the 'damon-dbgfs' to support the physical memory monitoring, in addition to the virtual memory monitoring.
Users can do the physical memory monitoring by writing a special keyword, 'paddr' to the 'target_ids' debugfs file. Then, DAMON will check the special keyword and configure the monitoring context to run with the primitives for the physical address space.
Unlike the virtual memory monitoring, the monitoring target region will not be automatically set. Therefore, users should also set the monitoring target address region using the 'init_regions' debugfs file.
Also, note that the physical memory monitoring will not automatically terminated. The user should explicitly turn off the monitoring by writing 'off' to the 'monitor_on' debugfs file.
Link: https://lkml.kernel.org/r/20211012205711.29216-7-sj@kernel.org Signed-off-by: SeongJae Park sj@kernel.org Cc: Amit Shah amit@kernel.org Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Brendan Higgins brendanhiggins@google.com Cc: David Hildenbrand david@redhat.com Cc: David Rienjes rientjes@google.com Cc: David Woodhouse dwmw@amazon.com Cc: Greg Thelen gthelen@google.com Cc: Jonathan Cameron Jonathan.Cameron@huawei.com Cc: Jonathan Corbet corbet@lwn.net Cc: Leonard Foerster foersleo@amazon.de Cc: Marco Elver elver@google.com Cc: Markus Boehme markubo@amazon.de Cc: Shakeel Butt shakeelb@google.com Cc: Shuah Khan shuah@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org (cherry picked from commit c026291ab88f02247999959d01182cb8eb6e6a5b) Signed-off-by: Yue Zou zouyue3@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- mm/damon/Kconfig | 2 +- mm/damon/dbgfs.c | 21 ++++++++++++++++++--- 2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig index 2a5923be631e..ca33b289ebbe 100644 --- a/mm/damon/Kconfig +++ b/mm/damon/Kconfig @@ -54,7 +54,7 @@ config DAMON_VADDR_KUNIT_TEST
config DAMON_DBGFS bool "DAMON debugfs interface" - depends on DAMON_VADDR && DEBUG_FS + depends on DAMON_VADDR && DAMON_PADDR && DEBUG_FS help This builds the debugfs interface for DAMON. The user space admins can use the interface for arbitrary data access monitoring. diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index 1cce53cd241d..38188347d8ab 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -339,6 +339,7 @@ static ssize_t dbgfs_target_ids_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct damon_ctx *ctx = file->private_data; + bool id_is_pid = true; char *kbuf, *nrs; unsigned long *targets; ssize_t nr_targets; @@ -351,6 +352,11 @@ static ssize_t dbgfs_target_ids_write(struct file *file, return PTR_ERR(kbuf);
nrs = kbuf; + if (!strncmp(kbuf, "paddr\n", count)) { + id_is_pid = false; + /* target id is meaningless here, but we set it just for fun */ + scnprintf(kbuf, count, "42 "); + }
targets = str_to_target_ids(nrs, ret, &nr_targets); if (!targets) { @@ -358,7 +364,7 @@ static ssize_t dbgfs_target_ids_write(struct file *file, goto out; }
- if (targetid_is_pid(ctx)) { + if (id_is_pid) { for (i = 0; i < nr_targets; i++) { targets[i] = (unsigned long)find_get_pid( (int)targets[i]); @@ -372,15 +378,24 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
mutex_lock(&ctx->kdamond_lock); if (ctx->kdamond) { - if (targetid_is_pid(ctx)) + if (id_is_pid) dbgfs_put_pids(targets, nr_targets); ret = -EBUSY; goto unlock_out; }
+ /* remove targets with previously-set primitive */ + damon_set_targets(ctx, NULL, 0); + + /* Configure the context for the address space type */ + if (id_is_pid) + damon_va_set_primitives(ctx); + else + damon_pa_set_primitives(ctx); + err = damon_set_targets(ctx, targets, nr_targets); if (err) { - if (targetid_is_pid(ctx)) + if (id_is_pid) dbgfs_put_pids(targets, nr_targets); ret = err; }