Re: [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
On Thu, Sep 26, 2019 at 10:55:47AM -0700, Kees Cook wrote: > Many architectures have an EXCEPTION_TABLE that needs only to be > read-only. As such, it should live in RO_DATA. This creates a macro to > identify this case for the architectures that can move EXCEPTION_TABLE > into RO_DATA. > > Signed-off-by: Kees Cook > --- > include/asm-generic/vmlinux.lds.h | 12 > 1 file changed, 12 insertions(+) > > diff --git a/include/asm-generic/vmlinux.lds.h > b/include/asm-generic/vmlinux.lds.h > index d57a28786bb8..35a6cba39d9f 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -69,6 +69,17 @@ > #define NOTES_HEADERS_RESTORE > #endif > > +/* > + * Some architectures have non-executable read-only exception tables. > + * They can be added to the RO_DATA segment by specifying their desired > + * alignment. > + */ > +#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN > +#define RO_DATA_EXCEPTION_TABLE > EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN) > +#else > +#define RO_DATA_EXCEPTION_TABLE > +#endif > + > /* Align . to a 8 byte boundary equals to maximum function alignment. */ > #define ALIGN_FUNCTION() . = ALIGN(8) > > @@ -508,6 +519,7 @@ > __stop___modver = .;\ > } \ > \ > + RO_DATA_EXCEPTION_TABLE \ > NOTES \ > \ > . = ALIGN((align)); \ > -- I think you can drop the "DATA" from the names as it is kinda clear where the exception table lands: RO_EXCEPTION_TABLE_ALIGN RO_EXCEPTION_TABLE The "read-only" part is the important one. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette
Re: [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
On Thu, Sep 26, 2019 at 10:55:47AM -0700, Kees Cook wrote: > Many architectures have an EXCEPTION_TABLE that needs only to be > read-only. As such, it should live in RO_DATA. This creates a macro to > identify this case for the architectures that can move EXCEPTION_TABLE > into RO_DATA. > > Signed-off-by: Kees Cook > --- > include/asm-generic/vmlinux.lds.h | 12 > 1 file changed, 12 insertions(+) > > diff --git a/include/asm-generic/vmlinux.lds.h > b/include/asm-generic/vmlinux.lds.h > index d57a28786bb8..35a6cba39d9f 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -69,6 +69,17 @@ > #define NOTES_HEADERS_RESTORE > #endif > > +/* > + * Some architectures have non-executable read-only exception tables. > + * They can be added to the RO_DATA segment by specifying their desired > + * alignment. > + */ > +#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN > +#define RO_DATA_EXCEPTION_TABLE > EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN) > +#else > +#define RO_DATA_EXCEPTION_TABLE > +#endif > + > /* Align . to a 8 byte boundary equals to maximum function alignment. */ > #define ALIGN_FUNCTION() . = ALIGN(8) > > @@ -508,6 +519,7 @@ > __stop___modver = .;\ > } \ > \ > + RO_DATA_EXCEPTION_TABLE \ > NOTES \ > \ > . = ALIGN((align)); \ I had to read this one to understand the later arm64 change. It looks fine to me, so: Acked-by: Will Deacon Will
[PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
Many architectures have an EXCEPTION_TABLE that needs only to be read-only. As such, it should live in RO_DATA. This creates a macro to identify this case for the architectures that can move EXCEPTION_TABLE into RO_DATA. Signed-off-by: Kees Cook --- include/asm-generic/vmlinux.lds.h | 12 1 file changed, 12 insertions(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index d57a28786bb8..35a6cba39d9f 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -69,6 +69,17 @@ #define NOTES_HEADERS_RESTORE #endif +/* + * Some architectures have non-executable read-only exception tables. + * They can be added to the RO_DATA segment by specifying their desired + * alignment. + */ +#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN +#define RO_DATA_EXCEPTION_TABLE EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN) +#else +#define RO_DATA_EXCEPTION_TABLE +#endif + /* Align . to a 8 byte boundary equals to maximum function alignment. */ #define ALIGN_FUNCTION() . = ALIGN(8) @@ -508,6 +519,7 @@ __stop___modver = .;\ } \ \ + RO_DATA_EXCEPTION_TABLE \ NOTES \ \ . = ALIGN((align)); \ -- 2.17.1
