linux.git/arch/powerpc/kernel/vmlinux.lds.S, branch v5.6

powerpc: Include .BTF section

2020-02-24T11:04:07+00:00

Selecting CONFIG_DEBUG_INFO_BTF results in the below warning from ld:
  ld: warning: orphan section `.BTF' from `.btf.vmlinux.bin.o' being placed in section `.BTF'

Include .BTF section in vmlinux explicitly to fix the same.

Signed-off-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200220113132.857132-1-naveen.n.rao@linux.vnet.ibm.com

powerpc: align stack to 2 * THREAD_SIZE with VMAP_STACK

2020-01-26T11:15:09+00:00

In order to ease stack overflow detection, align
stack to 2 * THREAD_SIZE when using VMAP_STACK.
This allows overflow detection using a single bit check.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/60e9ae86b7d2cdcf21468787076d345663648f46.1576916812.git.christophe.leroy@c-s.fr

powerpc: Move EXCEPTION_TABLE to RO_DATA segment

2019-11-04T17:30:13+00:00

Since the EXCEPTION_TABLE is read-only, collapse it into RO_DATA.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86-ml 
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-25-keescook@chromium.org

vmlinux.lds.h: Move NOTES into RO_DATA

2019-11-04T14:34:41+00:00

The .notes section should be non-executable read-only data. As such,
move it to the RO_DATA macro instead of being per-architecture defined.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Acked-by: Heiko Carstens  # s390
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86-ml 
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-11-keescook@chromium.org

vmlinux.lds.h: Move Program Header restoration into NOTES macro

2019-11-04T14:34:39+00:00

In preparation for moving NOTES into RO_DATA, make the Program Header
assignment restoration be part of the NOTES macro itself.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Acked-by: Heiko Carstens  # s390
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86-ml 
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-10-keescook@chromium.org

vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes

2019-11-04T14:34:38+00:00

In preparation for moving NOTES into RO_DATA, provide a mechanism for
architectures that want to emit a PT_NOTE Program Header to do so.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Acked-by: Heiko Carstens  # s390
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86-ml 
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-9-keescook@chromium.org

powerpc: Rename PT_LOAD identifier "kernel" to "text"

2019-11-04T14:34:11+00:00

In preparation for moving NOTES into RO_DATA, rename the linker script
internal identifier for the PT_LOAD Program Header from "kernel" to
"text" to match other architectures.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Acked-by: Michael Ellerman 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86@kernel.org
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-4-keescook@chromium.org

powerpc: Remove PT_NOTE workaround

2019-11-04T14:33:39+00:00

In preparation for moving NOTES into RO_DATA, remove the PT_NOTE
workaround since the kernel requires at least gcc 4.6 now.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Acked-by: Michael Ellerman 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86@kernel.org
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-3-keescook@chromium.org

powerpc: Rename "notes" PT_NOTE to "note"

2019-11-04T14:33:28+00:00

The Program Header identifiers are internal to the linker scripts. In
preparation for moving the NOTES segment declaration into RO_DATA,
standardize the identifier for the PT_NOTE entry to "note" as used by
all other architectures that emit PT_NOTE.

Note that there was discussion about changing all architectures to use
"notes" instead, but I prefer to avoid that at this time. Changing only
powerpc is the smallest change to standardize the entire kernel. And
while this standardization does use singular "note" for a section that
has more than one note in it, this is just an internal identifier. It
matches the ELF "PT_NOTE", and is 4 characters (like "text", and "data")
for pretty alignment. The more exposed macro, "NOTES", use the more
sensible plural wording.

Signed-off-by: Kees Cook 
Signed-off-by: Borislav Petkov 
Acked-by: Michael Ellerman 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Rick Edgecombe 
Cc: Segher Boessenkool 
Cc: Will Deacon 
Cc: x86-ml 
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20191029211351.13243-2-keescook@chromium.org

powerpc/kconfig: define CONFIG_DATA_SHIFT and CONFIG_ETEXT_SHIFT

2019-02-23T10:04:32+00:00

CONFIG_STRICT_KERNEL_RWX requires a special alignment
for DATA for some subarches. Today it is just defined
as an #ifdef in vmlinux.lds.S

In order to get more flexibility, this patch moves the
definition of this alignment in Kconfig

On some subarches, CONFIG_STRICT_KERNEL_RWX will
require a special alignment of _etext.

This patch also adds a configuration item for it in Kconfig

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman