[PATCH v2 07/29] x86: Restore "text" Program Header with dummy section

Kees Cook
2019-10-11T00:05:47Z

In a linker script, if once places a section in one or more segments using
":PHDR", then the linker will place all subsequent allocatable sections,
which do not specify ":PHDR", into the same segments. In order to have
the NOTES section in both PT_LOAD (":text") and PT_NOTE (":note"), both
segments are marked, and the only way to to undo this to keep subsequent
sections out of PT_NOTE is to mark the following section with just the
single desired PT_LOAD (":text").

In preparation for having a common NOTES macro, perform the segment
assignment use a dummy section (as done by other architectures).

Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/x86/kernel/vmlinux.lds.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e2feacf921a0..788e78978030 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -147,8 +147,9 @@ SECTIONS
} :text = 0x9090

NOTES :text :note
+ .dummy : { *(.dummy) } :text

- EXCEPTION_TABLE(16) :text = 0x9090
+ EXCEPTION_TABLE(16)

/* .text should occupy whole number of pages */
. = ALIGN(PAGE_SIZE);
--
2.17.1