Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes: > On Thu, 2012-12-27 at 13:44 +0200, Kalle Valo wrote: > >> + va_start(args, fmt); >> + vaf.va = &args; >> + ret = ath6kl_printk(KERN_WARNING, "%pV", &vaf); >> + va_end(args); > > Note that by inserting the tracing here later, you're relying on the > fact that "%pV" does va_copy(). This isn't true in all kernel versions, > I think there's on version or so where %pV is supported but didn't > va_copy(). That may lead to problems (I don't remember what kind) here. > > This is relevant for compat only, I think I carry a patch there to add > va_copy() into the tracing or something. Compat-drivers has 55-iwlwifi-msg-trace-fix.patch which says: "In recent kernels, %pV will copy the va_list before using it. This isn't true for all kernels, so copy the va_list for use by the dev_*() functions, otherwise the kernel will crash if the message is printed and traced." I take it that the problem happens when the message is both printed and traced at the same time. So ath6kl will need a similar patch as well. Thanks for the heads up. Kalle -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
