Commit graph

8 commits

Author SHA1 Message Date
Ard Biesheuvel
01142791b0 arm64: mm: avoid writable executable mappings in kexec/hibernate code
The temporary mappings of the low-level kexec and hibernate helpers are
created with both writable and executable attributes, which is not
necessary here, and generally best avoided. So use read-only, executable
attributes instead.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220429131347.3621090-3-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-17 09:32:45 +01:00
Pasha Tatashin
6091dd9eaf arm64: trans_pgd: remove trans_pgd_map_page()
The intend of trans_pgd_map_page() was to map contiguous range of VA
memory to the memory that is getting relocated during kexec. However,
since we are now using linear map instead of contiguous range this
function is not needed

Suggested-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-16-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-01 13:31:01 +01:00
Pasha Tatashin
788bfdd974 arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors
Users of trans_pgd may also need a copy of vector table because it is
also may be overwritten if a linear map can be overwritten.

Move setup of EL2 vectors from hibernate to trans_pgd, so it can be
later shared with kexec as well.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-3-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-01 13:30:59 +01:00
James Morse
7018d467ff arm64: trans_pgd: hibernate: idmap the single page that holds the copy page routines
To resume from hibernate, the contents of memory are restored from
the swap image. This may overwrite any page, including the running
kernel and its page tables.

Hibernate copies the code it uses to do the restore into a single
page that it knows won't be overwritten, and maps it with page tables
built from pages that won't be overwritten.

Today the address it uses for this mapping is arbitrary, but to allow
kexec to reuse this code, it needs to be idmapped. To idmap the page
we must avoid the kernel helpers that have VA_BITS baked in.

Convert create_single_mapping() to take a single PA, and idmap it.
The page tables are built in the reverse order to normal using
pfn_pte() to stir in any bits between 52:48. T0SZ is always increased
to cover 48bits, or 52 if the copy code has bits 52:48 in its PA.

Signed-off-by: James Morse <james.morse@arm.com>

[Adopted the original patch from James to trans_pgd interface, so it can be
commonly used by both Kexec and Hibernate. Some minor clean-ups.]

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/linux-arm-kernel/20200115143322.214247-4-james.morse@arm.com/
Link: https://lore.kernel.org/r/20210125191923.1060122-9-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-01-27 15:41:12 +00:00
Pavel Tatashin
5de59884ac arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions
trans_pgd_* should be independent from mm context because the tables that
are created by this code are used when there are no mm context around, as
it is between kernels. Simply replace mm_init's with NULL.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20210125191923.1060122-7-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-01-27 15:41:12 +00:00
Pavel Tatashin
89d1410f4a arm64: trans_pgd: pass allocator trans_pgd_create_copy
Make trans_pgd_create_copy and its subroutines to use allocator that is
passed as an argument

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20210125191923.1060122-6-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-01-27 15:41:12 +00:00
Pavel Tatashin
50f53fb721 arm64: trans_pgd: make trans_pgd_map_page generic
kexec is going to use a different allocator, so make
trans_pgd_map_page to accept allocator as an argument, and also
kexec is going to use a different map protection, so also pass
it via argument.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Link: https://lore.kernel.org/r/20210125191923.1060122-5-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-01-27 15:41:12 +00:00
Pavel Tatashin
072e3d96a7 arm64: hibernate: move page handling function to new trans_pgd.c
Now, that we abstracted the required functions move them to a new home.
Later, we will generalize these function in order to be useful outside
of hibernation.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20210125191923.1060122-4-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-01-27 15:41:11 +00:00