From: Martin Fuzzey <martin.fuzzey@flowbird.group> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "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 Subject: [PATCH] binder: fix log spam for existing debugfs file creation. Date: Fri, 10 Jan 2020 16:44:01 +0100 [thread overview] Message-ID: <1578671054-5982-1-git-send-email-martin.fuzzey@flowbird.group> (raw) Since commit 43e23b6c0b01 ("debugfs: log errors when something goes wrong") debugfs logs attempts to create existing files. However binder attempts to create multiple debugfs files with the same name when a single PID has multiple contexts, this leads to log spamming during an Android boot (17 such messages during boot on my system). Fix this by checking if we already know the PID and only create the debugfs entry for the first context per PID. Do the same thing for binderfs for symmetry. Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group> --- drivers/android/binder.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 976a694..254f87b 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5203,10 +5203,11 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma) static int binder_open(struct inode *nodp, struct file *filp) { - struct binder_proc *proc; + struct binder_proc *proc, *itr; struct binder_device *binder_dev; struct binderfs_info *info; struct dentry *binder_binderfs_dir_entry_proc = NULL; + bool existing_pid = false; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__, current->group_leader->pid, current->pid); @@ -5239,19 +5240,24 @@ static int binder_open(struct inode *nodp, struct file *filp) filp->private_data = proc; mutex_lock(&binder_procs_lock); + hlist_for_each_entry(itr, &binder_procs, proc_node) { + if (itr->pid == proc->pid) { + existing_pid = true; + break; + } + } hlist_add_head(&proc->proc_node, &binder_procs); mutex_unlock(&binder_procs_lock); - if (binder_debugfs_dir_entry_proc) { + if (binder_debugfs_dir_entry_proc && !existing_pid) { char strbuf[11]; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* - * proc debug entries are shared between contexts, so - * this will fail if the process tries to open the driver - * again with a different context. The priting code will - * anyway print all contexts that a given PID has, so this - * is not a problem. + * proc debug entries are shared between contexts. + * Only create for the first PID to avoid debugfs log spamming + * The printing code will anyway print all contexts for a given + * PID so this is not a problem. */ proc->debugfs_entry = debugfs_create_file(strbuf, 0444, binder_debugfs_dir_entry_proc, @@ -5259,19 +5265,16 @@ static int binder_open(struct inode *nodp, struct file *filp) &proc_fops); } - if (binder_binderfs_dir_entry_proc) { + if (binder_binderfs_dir_entry_proc && !existing_pid) { char strbuf[11]; struct dentry *binderfs_entry; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* * Similar to debugfs, the process specific log file is shared - * between contexts. If the file has already been created for a - * process, the following binderfs_create_file() call will - * fail with error code EEXIST if another context of the same - * process invoked binder_open(). This is ok since same as - * debugfs, the log file will contain information on all - * contexts of a given PID. + * between contexts. Only create for the first PID. + * This is ok since same as debugfs, the log file will contain + * information on all contexts of a given PID. */ binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc, strbuf, &proc_fops, (void *)(unsigned long)proc->pid); @@ -5281,10 +5284,8 @@ static int binder_open(struct inode *nodp, struct file *filp) int error; error = PTR_ERR(binderfs_entry); - if (error != -EEXIST) { - pr_warn("Unable to create file %s in binderfs (error %d)\n", - strbuf, error); - } + pr_warn("Unable to create file %s in binderfs (error %d)\n", + strbuf, error); } } -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Martin Fuzzey <martin.fuzzey@flowbird.group> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: devel@driverdev.osuosl.org, "Todd Kjos" <tkjos@android.com>, linux-kernel@vger.kernel.org, "Arve Hjønnevåg" <arve@android.com>, "Joel Fernandes" <joel@joelfernandes.org>, "Martijn Coenen" <maco@android.com>, "Christian Brauner" <christian@brauner.io> Subject: [PATCH] binder: fix log spam for existing debugfs file creation. Date: Fri, 10 Jan 2020 16:44:01 +0100 [thread overview] Message-ID: <1578671054-5982-1-git-send-email-martin.fuzzey@flowbird.group> (raw) Since commit 43e23b6c0b01 ("debugfs: log errors when something goes wrong") debugfs logs attempts to create existing files. However binder attempts to create multiple debugfs files with the same name when a single PID has multiple contexts, this leads to log spamming during an Android boot (17 such messages during boot on my system). Fix this by checking if we already know the PID and only create the debugfs entry for the first context per PID. Do the same thing for binderfs for symmetry. Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group> --- drivers/android/binder.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 976a694..254f87b 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5203,10 +5203,11 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma) static int binder_open(struct inode *nodp, struct file *filp) { - struct binder_proc *proc; + struct binder_proc *proc, *itr; struct binder_device *binder_dev; struct binderfs_info *info; struct dentry *binder_binderfs_dir_entry_proc = NULL; + bool existing_pid = false; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__, current->group_leader->pid, current->pid); @@ -5239,19 +5240,24 @@ static int binder_open(struct inode *nodp, struct file *filp) filp->private_data = proc; mutex_lock(&binder_procs_lock); + hlist_for_each_entry(itr, &binder_procs, proc_node) { + if (itr->pid == proc->pid) { + existing_pid = true; + break; + } + } hlist_add_head(&proc->proc_node, &binder_procs); mutex_unlock(&binder_procs_lock); - if (binder_debugfs_dir_entry_proc) { + if (binder_debugfs_dir_entry_proc && !existing_pid) { char strbuf[11]; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* - * proc debug entries are shared between contexts, so - * this will fail if the process tries to open the driver - * again with a different context. The priting code will - * anyway print all contexts that a given PID has, so this - * is not a problem. + * proc debug entries are shared between contexts. + * Only create for the first PID to avoid debugfs log spamming + * The printing code will anyway print all contexts for a given + * PID so this is not a problem. */ proc->debugfs_entry = debugfs_create_file(strbuf, 0444, binder_debugfs_dir_entry_proc, @@ -5259,19 +5265,16 @@ static int binder_open(struct inode *nodp, struct file *filp) &proc_fops); } - if (binder_binderfs_dir_entry_proc) { + if (binder_binderfs_dir_entry_proc && !existing_pid) { char strbuf[11]; struct dentry *binderfs_entry; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* * Similar to debugfs, the process specific log file is shared - * between contexts. If the file has already been created for a - * process, the following binderfs_create_file() call will - * fail with error code EEXIST if another context of the same - * process invoked binder_open(). This is ok since same as - * debugfs, the log file will contain information on all - * contexts of a given PID. + * between contexts. Only create for the first PID. + * This is ok since same as debugfs, the log file will contain + * information on all contexts of a given PID. */ binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc, strbuf, &proc_fops, (void *)(unsigned long)proc->pid); @@ -5281,10 +5284,8 @@ static int binder_open(struct inode *nodp, struct file *filp) int error; error = PTR_ERR(binderfs_entry); - if (error != -EEXIST) { - pr_warn("Unable to create file %s in binderfs (error %d)\n", - strbuf, error); - } + pr_warn("Unable to create file %s in binderfs (error %d)\n", + strbuf, error); } } -- 1.9.1 _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
next reply other threads:[~2020-01-10 15:44 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-10 15:44 Martin Fuzzey [this message] 2020-01-10 15:44 ` [PATCH] binder: fix log spam for existing debugfs file creation Martin Fuzzey 2020-01-14 15:22 ` Greg Kroah-Hartman 2020-01-14 15:22 ` Greg Kroah-Hartman 2020-01-17 22:30 ` Todd Kjos 2020-01-17 22:30 ` Todd Kjos
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1578671054-5982-1-git-send-email-martin.fuzzey@flowbird.group \ --to=martin.fuzzey@flowbird.group \ --cc=arve@android.com \ --cc=christian@brauner.io \ --cc=devel@driverdev.osuosl.org \ --cc=gregkh@linuxfoundation.org \ --cc=joel@joelfernandes.org \ --cc=linux-kernel@vger.kernel.org \ --cc=maco@android.com \ --cc=tkjos@android.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.