Messages in this thread | | | Date | Tue, 30 Jun 2015 14:20:47 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v4 04/17] context_tracking: Add ct_state and CT_WARN_ON |
| |
On Mon, Jun 29, 2015 at 12:33:36PM -0700, Andy Lutomirski wrote: > This will let us sprinkle sanity checks around the kernel without > making too much of a mess. > > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > include/linux/context_tracking.h | 15 +++++++++++++++ > include/linux/context_tracking_state.h | 1 + > 2 files changed, 16 insertions(+) > > diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h > index b96bd299966f..008fc67d0d96 100644 > --- a/include/linux/context_tracking.h > +++ b/include/linux/context_tracking.h > @@ -49,13 +49,28 @@ static inline void exception_exit(enum ctx_state prev_ctx) > } > } > > + > +/** > + * ct_state() - return the current context tracking state if known > + * > + * Returns the current cpu's context tracking state if context tracking
CPU's
> + * is enabled. If context tracking is disabled, returns > + * CONTEXT_DISABLED. This should be used primarily for debugging. > + */ > +static inline enum ctx_state ct_state(void) > +{ > + return context_tracking_is_enabled() ? > + this_cpu_read(context_tracking.state) : CONTEXT_DISABLED; > +} > #else > static inline void user_enter(void) { } > static inline void user_exit(void) { } > static inline enum ctx_state exception_enter(void) { return 0; } > static inline void exception_exit(enum ctx_state prev_ctx) { } > +static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; } > #endif /* !CONFIG_CONTEXT_TRACKING */ > > +#define CT_WARN_ON(cond) WARN_ON(context_tracking_is_enabled() && (cond))
Btw, that "CT_" prefix makes this look like it is the software controlling this thing:
https://upload.wikimedia.org/wikipedia/commons/thumb/2/27/UPMCEast_CTscan.jpg/1280px-UPMCEast_CTscan.jpg
:-)
Other kernel code uses "cxt" or "ctxt" abbreviations. Maybe
CTXT_WARN_ON(cond)
...
> #ifdef CONFIG_CONTEXT_TRACKING_FORCE > extern void context_tracking_init(void); > diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h > index 678ecdf90cf6..ee956c528fab 100644 > --- a/include/linux/context_tracking_state.h > +++ b/include/linux/context_tracking_state.h > @@ -14,6 +14,7 @@ struct context_tracking { > bool active; > int recursion; > enum ctx_state { > + CONTEXT_DISABLED = -1, /* returned by ct_state() if unknown */ > CONTEXT_KERNEL = 0, > CONTEXT_USER, > CONTEXT_GUEST,
And those then CTXT_*
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
| |