x86/vmlinux: Restore "text" Program Header with dummy section

In a linker script, if one 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 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 using a dummy section (as done by other architectures).

Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Rick Edgecombe <[email protected]>
Cc: Segher Boessenkool <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

1 files changed, 2 insertions, 1 deletions

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);