• Daniel Thompson's avatar
    kdb: Avoid printing KERN_ levels to consoles · f7d4ca8b
    Daniel Thompson authored
    Currently when kdb traps printk messages then the raw log level prefix
    (consisting of '\001' followed by a numeral) does not get stripped off
    before the message is issued to the various I/O handlers supported by
    kdb. This causes annoying visual noise as well as causing problems
    grepping for ^. It is also a change of behaviour compared to normal usage
    of printk() usage. For example <SysRq>-h ends up with different output to
    that of kdb's "sr h".
    This patch addresses the problem by stripping log levels from messages
    before they are issued to the I/O handlers. printk() which can also
    act as an i/o handler in some cases is special cased; if the caller
    provided a log level then the prefix will be preserved when sent to
    The addition of non-printable characters to the output of kdb commands is a
    regression, albeit and extremely elderly one, introduced by commit
    04d2c8c8 ("printk: convert the format for KERN_<LEVEL> to a 2 byte
    pattern"). Note also that this patch does *not* restore the original
    behaviour from v3.5. Instead it makes printk() from within a kdb command
    display the message without any prefix (i.e. like printk() normally does).
    Signed-off-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
    Cc: Joe Perches <joe@perches.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
kdb.h 7.32 KB