This is a note to let you know that I've just added the patch titled cifs: Ratelimit kernel log messages to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cifs-ratelimit-kernel-log-messages.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ec7147a99e33a9e4abad6fc6e1b40d15df045d53 Mon Sep 17 00:00:00 2001 From: Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx> Date: Sat, 7 Nov 2015 22:13:49 +1000 Subject: cifs: Ratelimit kernel log messages From: Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx> commit ec7147a99e33a9e4abad6fc6e1b40d15df045d53 upstream. Under some conditions, CIFS can repeatedly call the cifs_dbg() logging wrapper. If done rapidly enough, the console framebuffer can softlockup or "rcu_sched self-detected stall". Apply the built-in log ratelimiters to prevent such hangs. Signed-off-by: Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx> Signed-off-by: Steve French <smfrench@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/cifs/cifs_debug.c | 2 +- fs/cifs/cifs_debug.h | 9 ++++----- 2 files changed, 5 insertions(+), 6 deletions(-) --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -50,7 +50,7 @@ void cifs_vfs_err(const char *fmt, ...) vaf.fmt = fmt; vaf.va = &args; - pr_err("CIFS VFS: %pV", &vaf); + pr_err_ratelimited("CIFS VFS: %pV", &vaf); va_end(args); } --- a/fs/cifs/cifs_debug.h +++ b/fs/cifs/cifs_debug.h @@ -51,14 +51,13 @@ __printf(1, 2) void cifs_vfs_err(const c /* information message: e.g., configuration, major event */ #define cifs_dbg(type, fmt, ...) \ do { \ - if (type == FYI) { \ - if (cifsFYI & CIFS_INFO) { \ - pr_debug("%s: " fmt, __FILE__, ##__VA_ARGS__); \ - } \ + if (type == FYI && cifsFYI & CIFS_INFO) { \ + pr_debug_ratelimited("%s: " \ + fmt, __FILE__, ##__VA_ARGS__); \ } else if (type == VFS) { \ cifs_vfs_err(fmt, ##__VA_ARGS__); \ } else if (type == NOISY && type != 0) { \ - pr_debug(fmt, ##__VA_ARGS__); \ + pr_debug_ratelimited(fmt, ##__VA_ARGS__); \ } \ } while (0) Patches currently in stable-queue which might be from jamie.bainbridge@xxxxxxxxx are queue-4.4/cifs-ratelimit-kernel-log-messages.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html