linux.git/arch/arm64/kernel/pi/patch-scs.c, branch v6.12 Linux kernel source tree arm64: head: Move early kernel mapping routines into C code 2024-02-16T12:42:33+00:00 Ard Biesheuvel ardb@kernel.org 2024-02-14T12:29:04+00:00 97a6f43bb049e64b9913c50c7530e13d78e205d4 The asm version of the kernel mapping code works fine for creating a coarse grained identity map, but for mapping the kernel down to its exact boundaries with the right attributes, it is not suitable. This is why we create a preliminary RWX kernel mapping first, and then rebuild it from scratch later on. So let's reimplement this in C, in a way that will make it unnecessary to create the kernel page tables yet another time in paging_init(). Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-63-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
The asm version of the kernel mapping code works fine for creating a
coarse grained identity map, but for mapping the kernel down to its
exact boundaries with the right attributes, it is not suitable. This is
why we create a preliminary RWX kernel mapping first, and then rebuild
it from scratch later on.

So let's reimplement this in C, in a way that will make it unnecessary
to create the kernel page tables yet another time in paging_init().

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-63-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: head: move dynamic shadow call stack patching into early C runtime 2024-02-16T12:42:30+00:00 Ard Biesheuvel ardb@kernel.org 2024-02-14T12:28:55+00:00 8a6e40e1f68e9fc44497db88e0c0f21bb513c551 Once we update the early kernel mapping code to only map the kernel once with the right permissions, we can no longer perform code patching via this mapping. So move this code to an earlier stage of the boot, right after applying the relocations. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-54-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
Once we update the early kernel mapping code to only map the kernel once
with the right permissions, we can no longer perform code patching via
this mapping.

So move this code to an earlier stage of the boot, right after applying
the relocations.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-54-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>