From: Hridya Valsaraju <hridya@google.com>
To: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Arve Hjønnevåg" <arve@android.com>,
"Todd Kjos" <tkjos@android.com>,
"Martijn Coenen" <maco@android.com>,
"Joel Fernandes" <joel@joelfernandes.org>,
"Christian Brauner" <christian@brauner.io>,
devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Cc: kernel-team@android.com, Hridya Valsaraju <hridya@google.com>
Subject: [PATCH 1/4] binder: add a mount option to show global stats
Date: Tue, 27 Aug 2019 13:41:49 -0700 [thread overview]
Message-ID: <20190827204152.114609-2-hridya@google.com> (raw)
In-Reply-To: <20190827204152.114609-1-hridya@google.com>
Currently, all binder state and statistics live in debugfs.
We need this information even when debugfs is not mounted.
This patch adds the mount option 'stats' to enable a binderfs
instance to have binder debug information present in the same.
'stats=global' will enable the global binder statistics. In
the future, 'stats=local' will enable binder statistics local
to the binderfs instance. The two modes 'global' and 'local'
will be mutually exclusive. 'stats=global' option is only available
for a binderfs instance mounted in the initial user namespace.
An attempt to use the option to mount a binderfs instance in
another user namespace will return an EPERM error.
Signed-off-by: Hridya Valsaraju <hridya@google.com>
---
drivers/android/binderfs.c | 47 ++++++++++++++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 2 deletions(-)
diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index cc2e71576396..d95d179aec58 100644
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -51,18 +51,27 @@ static DEFINE_IDA(binderfs_minors);
/**
* binderfs_mount_opts - mount options for binderfs
* @max: maximum number of allocatable binderfs binder devices
+ * @stats_mode: enable binder stats in binderfs.
*/
struct binderfs_mount_opts {
int max;
+ int stats_mode;
};
enum {
Opt_max,
+ Opt_stats_mode,
Opt_err
};
+enum binderfs_stats_mode {
+ STATS_NONE,
+ STATS_GLOBAL,
+};
+
static const match_table_t tokens = {
{ Opt_max, "max=%d" },
+ { Opt_stats_mode, "stats=%s" },
{ Opt_err, NULL }
};
@@ -290,8 +299,9 @@ static void binderfs_evict_inode(struct inode *inode)
static int binderfs_parse_mount_opts(char *data,
struct binderfs_mount_opts *opts)
{
- char *p;
+ char *p, *stats;
opts->max = BINDERFS_MAX_MINOR;
+ opts->stats_mode = STATS_NONE;
while ((p = strsep(&data, ",")) != NULL) {
substring_t args[MAX_OPT_ARGS];
@@ -311,6 +321,24 @@ static int binderfs_parse_mount_opts(char *data,
opts->max = max_devices;
break;
+ case Opt_stats_mode:
+ stats = match_strdup(&args[0]);
+ if (!stats)
+ return -ENOMEM;
+
+ if (strcmp(stats, "global") != 0) {
+ kfree(stats);
+ return -EINVAL;
+ }
+
+ if (!capable(CAP_SYS_ADMIN)) {
+ kfree(stats);
+ return -EINVAL;
+ }
+
+ opts->stats_mode = STATS_GLOBAL;
+ kfree(stats);
+ break;
default:
pr_err("Invalid mount options\n");
return -EINVAL;
@@ -322,8 +350,21 @@ static int binderfs_parse_mount_opts(char *data,
static int binderfs_remount(struct super_block *sb, int *flags, char *data)
{
+ int prev_stats_mode, ret;
struct binderfs_info *info = sb->s_fs_info;
- return binderfs_parse_mount_opts(data, &info->mount_opts);
+
+ prev_stats_mode = info->mount_opts.stats_mode;
+ ret = binderfs_parse_mount_opts(data, &info->mount_opts);
+ if (ret)
+ return ret;
+
+ if (prev_stats_mode != info->mount_opts.stats_mode) {
+ pr_info("Binderfs stats mode cannot be changed during a remount\n");
+ info->mount_opts.stats_mode = prev_stats_mode;
+ return -EINVAL;
+ }
+
+ return 0;
}
static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root)
@@ -333,6 +374,8 @@ static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root)
info = root->d_sb->s_fs_info;
if (info->mount_opts.max <= BINDERFS_MAX_MINOR)
seq_printf(seq, ",max=%d", info->mount_opts.max);
+ if (info->mount_opts.stats_mode == STATS_GLOBAL)
+ seq_printf(seq, ",stats=global");
return 0;
}
--
2.23.0.187.g17f5b7556c-goog
next prev parent reply other threads:[~2019-08-27 20:42 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-27 20:41 [PATCH 0/4] Add binder state and statistics to binderfs Hridya Valsaraju
2019-08-27 20:41 ` Hridya Valsaraju [this message]
2019-08-28 9:22 ` [PATCH 1/4] binder: add a mount option to show global stats Greg Kroah-Hartman
2019-08-28 12:39 ` Christian Brauner
2019-08-28 17:21 ` Hridya Valsaraju
2019-08-27 20:41 ` [PATCH 2/4] binder: Add stats, state and transactions files Hridya Valsaraju
2019-08-28 12:58 ` Christian Brauner
2019-08-28 20:19 ` Hridya Valsaraju
2019-08-27 20:41 ` [PATCH 3/4] binder: Make transaction_log available in binderfs Hridya Valsaraju
2019-08-28 12:59 ` Christian Brauner
2019-08-28 16:05 ` Todd Kjos
2019-08-27 20:41 ` [PATCH 4/4] binder: Add binder_proc logging to binderfs Hridya Valsaraju
2019-08-28 13:08 ` Christian Brauner
2019-08-28 16:21 ` Todd Kjos
2019-08-28 20:42 ` Hridya Valsaraju
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