| Message ID | 1455638631-3326518-1-git-send-email-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16 February 2016 at 17:03, Arnd Bergmann <arnd@arndb.de> wrote: > When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error: > > arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned' > > However, this combination is useless, as XIP_KERNEL implies that all the > RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and > CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not > needed with XIP_KERNEL, and this patches enforces that using a Kconfig s/patches/patch/ > dependency. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA") > --- > arch/arm/mm/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig > index fbf2296388ce..8894045caba9 100644 > --- a/arch/arm/mm/Kconfig > +++ b/arch/arm/mm/Kconfig > @@ -1039,7 +1039,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN > > config DEBUG_RODATA > bool "Make kernel text and rodata read-only" > - depends on MMU > + depends on MMU && !XIP_KERNEL > default y if CPU_V7 > help > If this is set, kernel text and rodata memory will be made > -- > 2.7.0 >
On Tue, Feb 16, 2016 at 8:03 AM, Arnd Bergmann <arnd@arndb.de> wrote: > When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error: > > arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned' > > However, this combination is useless, as XIP_KERNEL implies that all the > RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and > CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not > needed with XIP_KERNEL, and this patches enforces that using a Kconfig > dependency. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA") Oh, hm, I didn't see this before sending my fix for the rodata start issue. > --- > arch/arm/mm/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig > index fbf2296388ce..8894045caba9 100644 > --- a/arch/arm/mm/Kconfig > +++ b/arch/arm/mm/Kconfig > @@ -1039,7 +1039,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN > > config DEBUG_RODATA > bool "Make kernel text and rodata read-only" > - depends on MMU > + depends on MMU && !XIP_KERNEL If we do this, we need to probably clean up the xip linker script to remove all the references to DEBUG_*RODATA too. -Kees > default y if CPU_V7 > help > If this is set, kernel text and rodata memory will be made > -- > 2.7.0 >
On Tue, Feb 16, 2016 at 8:03 AM, Arnd Bergmann <arnd@arndb.de> wrote: > When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error: > > arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned' > > However, this combination is useless, as XIP_KERNEL implies that all the > RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and > CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not > needed with XIP_KERNEL, and this patches enforces that using a Kconfig > dependency. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA") For this and the 2/2 patch: Acked-by: Kees Cook <keescook@chromium.org> I've sent follow-up to clean up the XIP linker script too, if you want to take that as the 3rd patch in this series of fixes. -Kees > --- > arch/arm/mm/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig > index fbf2296388ce..8894045caba9 100644 > --- a/arch/arm/mm/Kconfig > +++ b/arch/arm/mm/Kconfig > @@ -1039,7 +1039,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN > > config DEBUG_RODATA > bool "Make kernel text and rodata read-only" > - depends on MMU > + depends on MMU && !XIP_KERNEL > default y if CPU_V7 > help > If this is set, kernel text and rodata memory will be made > -- > 2.7.0 >
On Tue, Feb 16, 2016 at 12:31 PM, Kees Cook <keescook@chromium.org> wrote: > On Tue, Feb 16, 2016 at 8:03 AM, Arnd Bergmann <arnd@arndb.de> wrote: >> When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error: >> >> arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned' >> >> However, this combination is useless, as XIP_KERNEL implies that all the >> RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and >> CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not >> needed with XIP_KERNEL, and this patches enforces that using a Kconfig >> dependency. >> >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA") > > For this and the 2/2 patch: > > Acked-by: Kees Cook <keescook@chromium.org> > > I've sent follow-up to clean up the XIP linker script too, if you want > to take that as the 3rd patch in this series of fixes. Arnd, when you send your 2 patches to the tracker, can you also send mine (so the ordering is correct)? Thanks! -Kees
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index fbf2296388ce..8894045caba9 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -1039,7 +1039,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN config DEBUG_RODATA bool "Make kernel text and rodata read-only" - depends on MMU + depends on MMU && !XIP_KERNEL default y if CPU_V7 help If this is set, kernel text and rodata memory will be made
When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error: arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned' However, this combination is useless, as XIP_KERNEL implies that all the RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not needed with XIP_KERNEL, and this patches enforces that using a Kconfig dependency. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA") --- arch/arm/mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)