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| author | Ard Biesheuvel <ardb@kernel.org> | 2022-06-24 18:06:42 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-06-24 19:18:10 +0300 |
| commit | c3cee924bd855184d15bc4aa6088dcf8e2c1394c (patch) | |
| tree | afe531afe391eadbcdf03355a5c2e5b97df39a64 /arch/arm64/kernel/vmlinux.lds.S | |
| parent | b013c1e1c659b0742f81cc4a95fe61faf6929ae5 (diff) | |
| download | linux-c3cee924bd855184d15bc4aa6088dcf8e2c1394c.tar.xz | |
arm64: head: cover entire kernel image in initial ID map
As a first step towards avoiding the need to create, tear down and
recreate the kernel virtual mapping with MMU and caches disabled, start
by expanding the ID map so it covers the page tables as well as all
executable code. This will allow us to populate the page tables with the
MMU and caches on, and call KASLR init code before setting up the
virtual mapping.
Since this ID map is only needed at boot, create it as a temporary set
of page tables, and populate the permanent ID map after enabling the MMU
and caches. While at it, switch to read-only attributes for the where
possible, as writable permissions are only needed for the initial kernel
page tables. Note that on 4k granule configurations, the permanent ID
map will now be reduced to a single page rather than a 2M block mapping.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-13-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/vmlinux.lds.S')
| -rw-r--r-- | arch/arm64/kernel/vmlinux.lds.S | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 2d4a8f995175..533673793bc0 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -198,8 +198,7 @@ SECTIONS } idmap_pg_dir = .; - . += IDMAP_DIR_SIZE; - idmap_pg_end = .; + . += PAGE_SIZE; #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 tramp_pg_dir = .; @@ -235,6 +234,10 @@ SECTIONS __inittext_end = .; __initdata_begin = .; + init_idmap_pg_dir = .; + . += INIT_IDMAP_DIR_SIZE; + init_idmap_pg_end = .; + .init.data : { INIT_DATA INIT_SETUP(16) |