| Age | Commit message (Collapse) | Author |
|---|
|
commit 193383043f14a398393dc18bae8380f7fe665ec3 upstream.
Instead of open coding the generation of page table entries, use the
macros/functions that exist for this - pfn_p*d and p*d_populate. Most
code in the kernel already uses these macros, this patch tries to fix
up the few places that don't. This is useful for the next patch in this
series, which needs to change the page table entry logic, and it's
better to have that logic in one place.
The KVM extended ID map is special, since we're creating a level above
CONFIG_PGTABLE_LEVELS and the required function isn't available. Leave
it as is and add a comment to explain it. (The normal kernel ID map code
doesn't need this change because its page tables are created in assembly
(__create_page_tables)).
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit f7daa9c8fd191724b9ab9580a7be55cd1a67d799 upstream.
During resume hibernate restores all physical memory. Any memory
that is accessed with the MMU disabled needs to be cleaned to the
PoC.
KVMs __hyp_text was previously ommitted as it runs with the MMU
enabled, but now that the hyp-stub is located in this section,
we must clean __hyp_text too.
This ensures secondary CPUs that come online after hibernate
has finished resuming, and load KVM via the freshly written
hyp-stub see the correct instructions.
Signed-off-by: James Morse <james.morse@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 647d0519b53f440a55df163de21c52a8205431cc upstream.
On a system where firmware can dynamically change the state of the
mitigation, the CPU will always come up with the mitigation enabled,
including when coming back from suspend.
If the user has requested "no mitigation" via a command line option,
let's enforce it by calling into the firmware again to disable it.
Similarily, for a resume from hibernate, the mitigation could have
been disabled by the boot kernel. Let's ensure that it is set
back on in that case.
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Now that we use the MPIDR to resume on the same CPU that we hibernated on,
we no longer need to refuse to hibernate if the boot cpu is offline. (Which
we can't possibly know if kexec causes logical CPUs to be renumbered).
This reverts commit 1fe492ce6482b77807b25d29690a48c46456beee.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
disable_nonboot_cpus() assumes that the lowest numbered online CPU is
the boot CPU, and that this is the correct CPU to run any power
management code on.
On arm64 CPU0 can be taken offline. For hibernate/resume this means we
may hibernate on a CPU other than CPU0. If the system is rebooted with
kexec 'CPU0' will be assigned to a different CPU. This complicates
hibernate/resume as now we can't trust the CPU numbers.
We currently forbid hibernate if CPU0 has been hotplugged out to avoid
this situation without kexec.
Save the MPIDR of the CPU we hibernated on in the hibernate arch-header,
use hibernate_resume_nonboot_cpu_disable() to direct which CPU we should
resume on based on the MPIDR of the CPU we hibernated on. This allows us to
hibernate/resume on any CPU, even if the logical numbers have been
shuffled by kexec.
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
DEBUG_PAGEALLOC removes the valid bit of page table entries to prevent
any access to unallocated memory. Hibernate uses this as a hint that those
pages don't need to be saved/restored. This patch adds the
kernel_page_present() function it uses.
hibernate.c copies the resume kernel's linear map for use during restore.
Add _copy_pte() to fill-in the holes made by DEBUG_PAGEALLOC in the resume
kernel, so we can restore data the original kernel had at these addresses.
Finally, DEBUG_PAGEALLOC means the linear-map alias of KERNEL_START to
KERNEL_END may have holes in it, so we can't lazily clean this whole
area to the PoC. Only clean the new mmuoff region, and the kernel/kvm
idmaps.
This reverts commit da24eb1f3f9e2c7b75c5f8c40d8e48e2c4789596.
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
Each time new section markers are added, kernel/vmlinux.ld.S is updated,
and new extern char __start_foo[] definitions are scattered through the
tree.
Create asm/include/sections.h to collect these definitions (and include
the existing asm-generic version).
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
In create_safe_exec_page(), we create a copy of the hibernate exit text,
along with some page tables to map this via TTBR0. We then install the
new tables in TTBR0.
In swsusp_arch_resume() we call create_safe_exec_page() before trying a
number of operations which may fail (e.g. copying the linear map page
tables). If these fail, we bail out of swsusp_arch_resume() and return
an error code, but leave TTBR0 as-is. Subsequently, the core hibernate
code will call free_basic_memory_bitmaps(), which will free all of the
memory allocations we made, including the page tables installed in
TTBR0.
Thus, we may have TTBR0 pointing at dangling freed memory for some
period of time. If the hibernate attempt was triggered by a user
requesting a hibernate test via the reboot syscall, we may return to
userspace with the clobbered TTBR0 value.
Avoid these issues by reorganising swsusp_arch_resume() such that we
have no failure paths after create_safe_exec_page(). We also add a check
that the zero page allocation succeeded, matching what we have for other
allocations.
Fixes: 82869ac57b5d ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
In create_safe_exec_page we install a set of global mappings in TTBR0,
then subsequently invalidate TLBs. While TTBR0 points at the zero page,
and the TLBs should be free of stale global entries, we may have stale
ASID-tagged entries (e.g. from the EFI runtime services mappings) for
the same VAs. Per the ARM ARM these ASID-tagged entries may conflict
with newly-allocated global entries, and we must follow a
Break-Before-Make approach to avoid issues resulting from this.
This patch reworks create_safe_exec_page to invalidate TLBs while the
zero page is still in place, ensuring that there are no potential
conflicts when the new TTBR0 value is installed. As a single CPU is
online while this code executes, we do not need to perform broadcast TLB
maintenance, and can call local_flush_tlb_all(), which also subsumes
some barriers. The remaining assembly is converted to use write_sysreg()
and isb().
Other than this, we safely manipulate TTBRs in the hibernate dance. The
code we install as part of the new TTBR0 mapping (the hibernated
kernel's swsusp_arch_suspend_exit) installs a zero page into TTBR1,
invalidates TLBs, then installs its preferred value. Upon being restored
to the middle of swsusp_arch_suspend, the new image will call
__cpu_suspend_exit, which will call cpu_uninstall_idmap, installing the
zero page in TTBR0 and invalidating all TLB entries.
Fixes: 82869ac57b5d ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
Hibernate relies on cpu hotplug to prevent secondary cores executing
the kernel text while it is being restored.
Add a call to cpus_are_stuck_in_kernel() to determine if there are
CPUs not counted by 'num_online_cpus()', and prevent hibernate in this
case.
Fixes: 82869ac57b5 ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
Hibernation represents a system state save/restore through
a system reboot; this implies that the logical cpus carrying
out hibernation/thawing must be the same, so that the context
saved in the snapshot image on hibernation is consistent with
the state of the system on resume. If resume from hibernation
is driven through kernel command line parameter, the cpu responsible
for thawing the system will be whatever CPU firmware boots the system
on upon cold-boot (ie logical cpu 0); this means that in order to
keep system context consistent between the hibernate snapshot image
and system state on kernel resume from hibernate, logical cpu 0 must
be online on hibernation and must be the logical cpu that creates
the snapshot image.
This patch adds a PM notifier that enforces logical cpu 0 is online
when the hibernation is started (and prevents hibernation if it is
not), which is sufficient to guarantee it will be the one creating
the snapshot image therefore providing the resume cpu a consistent
snapshot of the system to resume to.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
Add support for hibernate/suspend-to-disk.
Suspend borrows code from cpu_suspend() to write cpu state onto the stack,
before calling swsusp_save() to save the memory image.
Restore creates a set of temporary page tables, covering only the
linear map, copies the restore code to a 'safe' page, then uses the copy to
restore the memory image. The copied code executes in the lower half of the
address space, and once complete, restores the original kernel's page
tables. It then calls into cpu_resume(), and follows the normal
cpu_suspend() path back into the suspend code.
To restore a kernel using KASLR, the address of the page tables, and
cpu_resume() are stored in the hibernate arch-header and the el2
vectors are pivotted via the 'safe' page in low memory.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Kevin Hilman <khilman@baylibre.com> # Tested on Juno R2
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
