arm64: mm: fold alternatives into .init

Currently we treat the alternatives separately from other data that's
only used during initialisation, using separate .altinstructions and
.altinstr_replacement linker sections. These are freed for general
allocation separately from .init*. This is problematic as:

* We do not remove execute permissions, as we do for .init, leaving the
  memory executable.

* We pad between them, making the kernel Image bianry up to PAGE_SIZE
  bytes larger than necessary.

This patch moves the two sections into the contiguous region used for
.init*. This saves some memory, ensures that we remove execute
permissions, and allows us to remove some code made redundant by this
reorganisation.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index ab9db0e..d2ee1b2 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -158,9 +158,3 @@ void apply_alternatives(void *start, size_t length)
 
 	__apply_alternatives(&region);
 }
-
-void free_alternatives_memory(void)
-{
-	free_reserved_area(__alt_instructions, __alt_instructions_end,
-			   0, "alternatives");
-}