* [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm
@ 2016-10-21 16:17 Steven Rostedt
2016-10-21 23:44 ` Nicholas Piggin
0 siblings, 1 reply; 5+ messages in thread
From: Steven Rostedt @ 2016-10-21 16:17 UTC (permalink / raw)
To: LKML, Al Viro
Cc: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Gabriel C, npiggin
Commit 784d5699eddc5 ("x86: move exports to actual definitions") removed the
EXPORT_SYMBOL(__fentry__) and EXPORT_SYMBOL(mcount) from x8664_ksyms_64.c,
and added EXPORT_SYMBOL(function_hook) in mcount_64.S instead. The problem
is that function_hook isn't a function at all, but a macro that is defined
as eithe mcount or __fentry__ depending on the support from gcc. But instead
of adding more #ifdefs like x8684_ksyms_64.c had, I suggest having another
export that can handle this similar to the way __string() works with
converting macros to strings. By having:
EXPORT_MACRO_SYMBOL(function_hook)
Where we have:
#define EXPORT_MACRO_SYMBOL(x) EXPORT_SYMBOL(x)
It will convert the macro into what it is defined as before calling
EXPORT_SYMBOL(), and this will just work properly again.
Cc: stable@vger.kernel.org
Fixes: Commit 784d5699eddc5 ("x86: move exports to actual definitions")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86/kernel/mcount_64.S | 2 +-
include/asm-generic/export.h | 5 +++++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index efe73aacf966..ccd9d912af27 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -295,7 +295,7 @@ trace:
jmp fgraph_trace
END(function_hook)
#endif /* CONFIG_DYNAMIC_FTRACE */
-EXPORT_SYMBOL(function_hook)
+EXPORT_MACRO_SYMBOL(function_hook)
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
index 43199a049da5..cb86e746865e 100644
--- a/include/asm-generic/export.h
+++ b/include/asm-generic/export.h
@@ -90,5 +90,10 @@
__EXPORT_SYMBOL(name, KSYM(name),)
#define EXPORT_DATA_SYMBOL_GPL(name) \
__EXPORT_SYMBOL(name, KSYM(name),_gpl)
+/*
+ * If "name" is a macro of a function and not a function itself,
+ * it needs a second pass.
+ */
+#define EXPORT_MACRO_SYMBOL(x) EXPORT_SYMBOL(x)
#endif
--
1.9.3
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm
2016-10-21 16:17 [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm Steven Rostedt
@ 2016-10-21 23:44 ` Nicholas Piggin
2016-10-22 19:08 ` Steven Rostedt
0 siblings, 1 reply; 5+ messages in thread
From: Nicholas Piggin @ 2016-10-21 23:44 UTC (permalink / raw)
To: Steven Rostedt
Cc: LKML, Al Viro, Borislav Petkov, Thomas Gleixner, Ingo Molnar, Gabriel C
On Fri, 21 Oct 2016 12:17:59 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> Commit 784d5699eddc5 ("x86: move exports to actual definitions") removed the
> EXPORT_SYMBOL(__fentry__) and EXPORT_SYMBOL(mcount) from x8664_ksyms_64.c,
> and added EXPORT_SYMBOL(function_hook) in mcount_64.S instead. The problem
> is that function_hook isn't a function at all, but a macro that is defined
> as eithe mcount or __fentry__ depending on the support from gcc. But instead
> of adding more #ifdefs like x8684_ksyms_64.c had, I suggest having another
> export that can handle this similar to the way __string() works with
> converting macros to strings. By having:
>
> EXPORT_MACRO_SYMBOL(function_hook)
>
> Where we have:
>
> #define EXPORT_MACRO_SYMBOL(x) EXPORT_SYMBOL(x)
>
> It will convert the macro into what it is defined as before calling
> EXPORT_SYMBOL(), and this will just work properly again.
>
> Cc: stable@vger.kernel.org
> Fixes: Commit 784d5699eddc5 ("x86: move exports to actual definitions")
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> ---
> arch/x86/kernel/mcount_64.S | 2 +-
> include/asm-generic/export.h | 5 +++++
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
> index efe73aacf966..ccd9d912af27 100644
> --- a/arch/x86/kernel/mcount_64.S
> +++ b/arch/x86/kernel/mcount_64.S
> @@ -295,7 +295,7 @@ trace:
> jmp fgraph_trace
> END(function_hook)
> #endif /* CONFIG_DYNAMIC_FTRACE */
> -EXPORT_SYMBOL(function_hook)
> +EXPORT_MACRO_SYMBOL(function_hook)
> #endif /* CONFIG_FUNCTION_TRACER */
>
> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
> index 43199a049da5..cb86e746865e 100644
> --- a/include/asm-generic/export.h
> +++ b/include/asm-generic/export.h
> @@ -90,5 +90,10 @@
> __EXPORT_SYMBOL(name, KSYM(name),)
> #define EXPORT_DATA_SYMBOL_GPL(name) \
> __EXPORT_SYMBOL(name, KSYM(name),_gpl)
> +/*
> + * If "name" is a macro of a function and not a function itself,
> + * it needs a second pass.
> + */
> +#define EXPORT_MACRO_SYMBOL(x) EXPORT_SYMBOL(x)
Seems okay, but what about just calling it EXPORT_SYMBOL?
Thanks,
Nick
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm
2016-10-21 23:44 ` Nicholas Piggin
@ 2016-10-22 19:08 ` Steven Rostedt
2016-10-24 1:25 ` Nicholas Piggin
0 siblings, 1 reply; 5+ messages in thread
From: Steven Rostedt @ 2016-10-22 19:08 UTC (permalink / raw)
To: Nicholas Piggin
Cc: LKML, Al Viro, Borislav Petkov, Thomas Gleixner, Ingo Molnar, Gabriel C
On Sat, 22 Oct 2016 10:44:41 +1100
Nicholas Piggin <npiggin@gmail.com> wrote:
> > #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> > diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
> > index 43199a049da5..cb86e746865e 100644
> > --- a/include/asm-generic/export.h
> > +++ b/include/asm-generic/export.h
> > @@ -90,5 +90,10 @@
> > __EXPORT_SYMBOL(name, KSYM(name),)
> > #define EXPORT_DATA_SYMBOL_GPL(name) \
> > __EXPORT_SYMBOL(name, KSYM(name),_gpl)
> > +/*
> > + * If "name" is a macro of a function and not a function itself,
> > + * it needs a second pass.
> > + */
> > +#define EXPORT_MACRO_SYMBOL(x) EXPORT_SYMBOL(x)
>
> Seems okay, but what about just calling it EXPORT_SYMBOL?
Actually, this doesn't work. There's some magic going on it
Makefile.build in the scripts directory that causes this to fail.
I have another patch I'll be sending on Monday that fixes this.
-- Steve
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm
2016-10-22 19:08 ` Steven Rostedt
@ 2016-10-24 1:25 ` Nicholas Piggin
2016-10-24 14:14 ` Steven Rostedt
0 siblings, 1 reply; 5+ messages in thread
From: Nicholas Piggin @ 2016-10-24 1:25 UTC (permalink / raw)
To: Steven Rostedt
Cc: LKML, Al Viro, Borislav Petkov, Thomas Gleixner, Ingo Molnar, Gabriel C
On Sat, 22 Oct 2016 15:08:52 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Sat, 22 Oct 2016 10:44:41 +1100
> Nicholas Piggin <npiggin@gmail.com> wrote:
>
> > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> > > diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
> > > index 43199a049da5..cb86e746865e 100644
> > > --- a/include/asm-generic/export.h
> > > +++ b/include/asm-generic/export.h
> > > @@ -90,5 +90,10 @@
> > > __EXPORT_SYMBOL(name, KSYM(name),)
> > > #define EXPORT_DATA_SYMBOL_GPL(name) \
> > > __EXPORT_SYMBOL(name, KSYM(name),_gpl)
> > > +/*
> > > + * If "name" is a macro of a function and not a function itself,
> > > + * it needs a second pass.
> > > + */
> > > +#define EXPORT_MACRO_SYMBOL(x) EXPORT_SYMBOL(x)
> >
> > Seems okay, but what about just calling it EXPORT_SYMBOL?
>
>
> Actually, this doesn't work. There's some magic going on it
> Makefile.build in the scripts directory that causes this to fail.
>
> I have another patch I'll be sending on Monday that fixes this.
Yes it's grepping for EXPORT_SYMBOL_* I think. If you need to
create a new name, EXPORT_SYMBOL prefix would be preferred. But
yeah if you make the standard macro do macro expansion, it
should just work, no?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm
2016-10-24 1:25 ` Nicholas Piggin
@ 2016-10-24 14:14 ` Steven Rostedt
0 siblings, 0 replies; 5+ messages in thread
From: Steven Rostedt @ 2016-10-24 14:14 UTC (permalink / raw)
To: Nicholas Piggin
Cc: LKML, Al Viro, Borislav Petkov, Thomas Gleixner, Ingo Molnar, Gabriel C
On Mon, 24 Oct 2016 12:25:45 +1100
Nicholas Piggin <npiggin@gmail.com> wrote:
> Yes it's grepping for EXPORT_SYMBOL_* I think. If you need to
> create a new name, EXPORT_SYMBOL prefix would be preferred. But
> yeah if you make the standard macro do macro expansion, it
> should just work, no?
Unfortunately, that's not enough. There's some magic in the Makefile
that seems to use the names found in EXPORT_SYMBOL*, which fails when
that name is just a macro to another name.
I'm just going to punt and include both names depending on the config.
-- Steve
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-10-24 14:14 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-10-21 16:17 [RFC][PATCH] Add EXPORT_MACRO_SYMBOL() for asm Steven Rostedt
2016-10-21 23:44 ` Nicholas Piggin
2016-10-22 19:08 ` Steven Rostedt
2016-10-24 1:25 ` Nicholas Piggin
2016-10-24 14:14 ` Steven Rostedt
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).