[regression,drm/noveau] suspend to ram -> BOOM: exception RIP: drm_calc_vbltimestamp_from_scanoutpos+335

Commit Message

Josh Poimboeuf July 14, 2017, 7:42 p.m. UTC

On Fri, Jul 14, 2017 at 06:33:01PM +0200, Mike Galbraith wrote:
> On Fri, 2017-07-14 at 18:10 +0200, Peter Zijlstra wrote:
> > On Fri, Jul 14, 2017 at 05:58:18PM +0200, Mike Galbraith wrote:
> > > On Fri, 2017-07-14 at 17:50 +0200, Peter Zijlstra wrote:
> > 
> > > > Urgh, is for some mysterious reason the __bug_table section of modules
> > > > ending up in RO memory?
> > > > 
> > > > I forever get lost in that link magic :/
> > > 
> > > +1
> > > 
> > > drm.ko
> > >  20 __bug_table   00000630  0000000000000000  0000000000000000  0004bff3  2**0
> > >                   CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA
> > > vmlinux
> > >  15 __bug_table   0000ba84  ffffffff81af26c0  0000000001af26c0  00cf26c0  2**0
> > >                   CONTENTS, ALLOC, LOAD, READONLY, DATA
> > > 
> > > Danged if I know... um um RELOC business mucks things up?
> > 
> > Argh, it shouldn't be READONLY for vmlinux either, but apparently that
> > is working for mysterious reasons.
> > 
> > Some architectures were in fact complaining that I broke that, and hence
> > patch:
> > 
> > b5effd3815cc ("debug: Fix __bug_table[] in arch linker scripts")
> > 
> > I think we need professional help with this linking stuff, but who to
> > ask?
> 
> Andy Lutomirski?

Does this fix it?

Comments

Mike Galbraith July 15, 2017, 2:45 a.m. UTC | #1

On Fri, 2017-07-14 at 14:42 -0500, Josh Poimboeuf wrote:
> 
> Does this fix it?

Yup, both READONLY __bug_table and "extra stern" warning are gone.

> diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
> index 39e702d..aa6b202 100644
> --- a/arch/x86/include/asm/bug.h
> +++ b/arch/x86/include/asm/bug.h
> @@ -35,7 +35,7 @@
>  #define _BUG_FLAGS(ins, flags)						\
>  do {									\
>  	asm volatile("1:\t" ins "\n"					\
> -		     ".pushsection __bug_table,\"a\"\n"			\
> +		     ".pushsection __bug_table,\"aw\"\n"		\
>  		     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"	\
>  		     "\t"  __BUG_REL(%c0) "\t# bug_entry::file\n"	\
>  		     "\t.word %c1"        "\t# bug_entry::line\n"	\
> @@ -52,7 +52,7 @@ do {									\
>  #define _BUG_FLAGS(ins, flags)						\
>  do {									\
>  	asm volatile("1:\t" ins "\n"					\
> -		     ".pushsection __bug_table,\"a\"\n"			\
> +		     ".pushsection __bug_table,\"aw\"\n"		\
>  		     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"	\
>  		     "\t.word %c0"        "\t# bug_entry::flags\n"	\
>  		     "\t.org 2b+%c1\n"					\

Patch

diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 39e702d..aa6b202 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -35,7 +35,7 @@ 
 #define _BUG_FLAGS(ins, flags)						\
 do {									\
 	asm volatile("1:\t" ins "\n"					\
-		     ".pushsection __bug_table,\"a\"\n"			\
+		     ".pushsection __bug_table,\"aw\"\n"		\
 		     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"	\
 		     "\t"  __BUG_REL(%c0) "\t# bug_entry::file\n"	\
 		     "\t.word %c1"        "\t# bug_entry::line\n"	\
@@ -52,7 +52,7 @@  do {									\
 #define _BUG_FLAGS(ins, flags)						\
 do {									\
 	asm volatile("1:\t" ins "\n"					\
-		     ".pushsection __bug_table,\"a\"\n"			\
+		     ".pushsection __bug_table,\"aw\"\n"		\
 		     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"	\
 		     "\t.word %c0"        "\t# bug_entry::flags\n"	\
 		     "\t.org 2b+%c1\n"					\