search for: __bug_table

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...

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 > >                   ...

...ike 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  000...

+++ Peter Zijlstra [14/07/17 18:10 +0200]: >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, AL...

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) \...

...16bb3819da73f0a8b28a8 is the first bad commit > commit 19d436268dde95389c616bb3819da73f0a8b28a8 > Author: Peter Zijlstra <peterz at infradead.org> > Date: Sat Feb 25 08:56:53 2017 +0100 > > debug: Add _ONCE() logic to report_bug() 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 :/

...bad commit > > commit 19d436268dde95389c616bb3819da73f0a8b28a8 > > Author: Peter Zijlstra <peterz at infradead.org> > > Date: Sat Feb 25 08:56:53 2017 +0100 > > > > debug: Add _ONCE() logic to report_bug() > > 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 ffffffff8...

On Wed, 2017-07-12 at 07:37 -0400, Ilia Mirkin wrote: > On Wed, Jul 12, 2017 at 7:25 AM, Mike Galbraith <efault at gmx.de> wrote: > > On Wed, 2017-07-12 at 11:55 +0200, Mike Galbraith wrote: > >> On Tue, 2017-07-11 at 14:22 -0400, Ilia Mirkin wrote: > >> > > >> > Some display stuff did change for 4.13 for GM20x+ boards. If it's not > >>

...;.long " __stringify(val) +#else +# define __BUG_REL(val) ".long " __stringify(val) " - 2b" +#endif + +#ifdef CONFIG_DEBUG_BUGVERBOSE + +#define _BUG_FLAGS(ins, flags) \ +do { \ + asm volatile("1:\t" ins "\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" \ + "\t.word %c2" &qu...

...;.long " __stringify(val) +#else +# define __BUG_REL(val) ".long " __stringify(val) " - 2b" +#endif + +#ifdef CONFIG_DEBUG_BUGVERBOSE + +#define _BUG_FLAGS(ins, flags) \ +do { \ + asm volatile("1:\t" ins "\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" \ + "\t.word %c2" &qu...

...;.long " __stringify(val) +#else +# define __BUG_REL(val) ".long " __stringify(val) " - 2b" +#endif + +#ifdef CONFIG_DEBUG_BUGVERBOSE + +#define _BUG_FLAGS(ins, flags) \ +do { \ + asm volatile("1:\t" ins "\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" \ + "\t.word %c2" &qu...

...0x8) Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> --- scripts/mod/modpost.c | 1 + 1 file changed, 1 insertion(+) --- linux-2.6.19-git17.orig/scripts/mod/modpost.c +++ linux-2.6.19-git17/scripts/mod/modpost.c @@ -997,6 +997,7 @@ static int exit_section_ref_ok(const cha "__bug_table", /* used by powerpc for BUG() */ ".exitcall.exit", ".eh_frame", + ".parainstructions", ".stab", "__ex_table", ".fixup",

...0x8) Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> --- scripts/mod/modpost.c | 1 + 1 file changed, 1 insertion(+) --- linux-2.6.19-git17.orig/scripts/mod/modpost.c +++ linux-2.6.19-git17/scripts/mod/modpost.c @@ -997,6 +997,7 @@ static int exit_section_ref_ok(const cha "__bug_table", /* used by powerpc for BUG() */ ".exitcall.exit", ".eh_frame", + ".parainstructions", ".stab", "__ex_table", ".fixup",

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

Changes: - patch v3: - Update on message to describe longer term PIE goal. - Minor change on ftrace if condition. - Changed code using xchgq. - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace

Changes: - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce dynamic relocation space on mapped memory. It also simplifies the relocation process. - Move the start the module section next to the kernel. Remove the need for -mcmodel=large on modules. Extends

Changes: - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce dynamic relocation space on mapped memory. It also simplifies the relocation process. - Move the start the module section next to the kernel. Remove the need for -mcmodel=large on modules. Extends