[PATCH v3 08/16] Warn when attempting to log in a signal unsafe manner from signal context
Peter Hutterer
peter.hutterer at who-t.net
Thu May 10 23:23:46 PDT 2012
On Mon, Apr 16, 2012 at 11:30:22AM -0700, Chase Douglas wrote:
> On 04/16/2012 11:14 AM, Chase Douglas wrote:
> > Also, print out the offending message format. This will hopefully help
> > developers track down unsafe logging.
> >
> > Signed-off-by: Chase Douglas <chase.douglas at canonical.com>
> > ---
> > os/log.c | 26 ++++++++++++++++++++++++++
> > 1 files changed, 26 insertions(+), 0 deletions(-)
> >
> > diff --git a/os/log.c b/os/log.c
> > index 3747fe0..36e678e 100644
> > --- a/os/log.c
> > +++ b/os/log.c
> > @@ -352,6 +352,16 @@ LogVWrite(int verb, const char *f, va_list args)
> > int len = 0;
> > static Bool newline = TRUE;
> >
> > + if (inSignalContext) {
> > + BUG_WARN_MSG(inSignalContext,
> > + "Warning: attempting to log data in a signal unsafe "
> > + "manner while in signal context. Please update to check "
> > + "inSignalContext and/or use LogMessageVerbSigSafe() or "
> > + "ErrorSigSafe(). The offending log format message is: "
> > + "%s\n", f);
> > + return;
> > + }
> > +
> > if (newline) {
> > sprintf(tmpBuffer, "[%10.3f] ", GetTimeInMillis() / 1000.0);
> > len = strlen(tmpBuffer);
> > @@ -578,6 +588,22 @@ LogVHdrMessageVerb(MessageType type, int verb, const char *msg_format,
> > char *p;
> > int left;
> >
> > + if (inSignalContext) {
> > + static const char warning[] = "Warning: attempting to log data in a "
> > + "signal unsafe manner while in signal "
> > + "context. Please update to check "
> > + "inSignalContext and/or use "
> > + "LogMessageVerbSigSafe(). The offending "
> > + "header and log message formats are:\n";
> > +
> > + write(logFileFd, warning, sizeof(warning) - 1);
> > +
> > + write(logFileFd, hdr_format, strlen_sigsafe(hdr_format));
> > + write(logFileFd, msg_format, strlen_sigsafe(msg_format));
> > +
> > + return;
> > + }
> > +
>
> I forgot to fix up this second hunk. I have pushed a fixed version to my
> branch at fdo. It basically does the same thing as the first hunk.
how about a define for the message? I don't think the header is that
important, the log message alone should be enough to identify (or print a
backtrace here)
Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net> otherwise
Cheers,
Peter
More information about the xorg-devel
mailing list