set_memory_p() is available to use outside of its compilation unit since:
030ad7af94 ("x86/mm: Regularize set_memory_p() parameters and make non-static").
There is no use for __set_memory_prot() anymore so drop it too.
[ bp: Massage commit message. ]
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260106095100.656292-1-coxu@redhat.com
emulator in favor of int3_emulate_jcc() which is written in C
- Replace KVM fastops with C-based stubs which avoids problems with the
fastop infra related to latter not adhering to the C ABI due to their
special calling convention and, more importantly, bypassing compiler
control-flow integrity checking because they're written in asm
- Remove wrongly used static branches and other ugliness accumulated
over time in hyperv's hypercall implementation with a proper static
function call to the correct hypervisor call variant
- Add some fixes and modifications to allow running FRED-enabled kernels
in KVM even on non-FRED hardware
- Add kCFI improvements like validating indirect calls and prepare for
enabling kCFI with GCC. Add cmdline params documentation and other
code cleanups
- Use the single-byte 0xd6 insn as the official #UD single-byte
undefined opcode instruction as agreed upon by both x86 vendors
- Other smaller cleanups and touchups all over the place
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Merge tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more x86 updates from Borislav Petkov:
- Remove a bunch of asm implementing condition flags testing in KVM's
emulator in favor of int3_emulate_jcc() which is written in C
- Replace KVM fastops with C-based stubs which avoids problems with the
fastop infra related to latter not adhering to the C ABI due to their
special calling convention and, more importantly, bypassing compiler
control-flow integrity checking because they're written in asm
- Remove wrongly used static branches and other ugliness accumulated
over time in hyperv's hypercall implementation with a proper static
function call to the correct hypervisor call variant
- Add some fixes and modifications to allow running FRED-enabled
kernels in KVM even on non-FRED hardware
- Add kCFI improvements like validating indirect calls and prepare for
enabling kCFI with GCC. Add cmdline params documentation and other
code cleanups
- Use the single-byte 0xd6 insn as the official #UD single-byte
undefined opcode instruction as agreed upon by both x86 vendors
- Other smaller cleanups and touchups all over the place
* tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86,retpoline: Optimize patch_retpoline()
x86,ibt: Use UDB instead of 0xEA
x86/cfi: Remove __noinitretpoline and __noretpoline
x86/cfi: Add "debug" option to "cfi=" bootparam
x86/cfi: Standardize on common "CFI:" prefix for CFI reports
x86/cfi: Document the "cfi=" bootparam options
x86/traps: Clarify KCFI instruction layout
compiler_types.h: Move __nocfi out of compiler-specific header
objtool: Validate kCFI calls
x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y
x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware
x86/fred: Install system vector handlers even if FRED isn't fully enabled
x86/hyperv: Use direct call to hypercall-page
x86/hyperv: Clean up hv_do_hypercall()
KVM: x86: Remove fastops
KVM: x86: Convert em_salc() to C
KVM: x86: Introduce EM_ASM_3WCL
KVM: x86: Introduce EM_ASM_1SRC2
KVM: x86: Introduce EM_ASM_2CL
KVM: x86: Introduce EM_ASM_2W
...
Some early TDX-capable platforms have an erratum: A kernel partial
write (a write transaction of less than cacheline lands at memory
controller) to TDX private memory poisons that memory, and a subsequent
read triggers a machine check.
On those platforms, the old kernel must reset TDX private memory before
jumping to the new kernel, otherwise the new kernel may see unexpected
machine check. Currently the kernel doesn't track which page is a TDX
private page. For simplicity just fail kexec/kdump for those platforms.
Leverage the existing machine_kexec_prepare() to fail kexec/kdump by
adding the check of the presence of the TDX erratum (which is only
checked for if the kernel is built with TDX host support). This rejects
kexec/kdump when the kernel is loading the kexec/kdump kernel image.
The alternative is to reject kexec/kdump when the kernel is jumping to
the new kernel. But for kexec this requires adding a new check (e.g.,
arch_kexec_allowed()) in the common code to fail kernel_kexec() at early
stage. Kdump (crash_kexec()) needs similar check, but it's hard to
justify because crash_kexec() is not supposed to abort.
It's feasible to further relax this limitation, i.e., only fail kexec
when TDX is actually enabled by the kernel. But this is still a half
measure compared to resetting TDX private memory so just do the simplest
thing for now.
The impact to userspace is the users will get an error when loading the
kexec/kdump kernel image:
kexec_load failed: Operation not supported
This might be confusing to the users, thus also print the reason in the
dmesg:
[..] kexec: Not allowed on platform with tdx_pw_mce bug.
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Farrah Chen <farrah.chen@intel.com>
Link: https://lore.kernel.org/all/20250901160930.1785244-5-pbonzini%40redhat.com
TL;DR:
Prepare to unify how TDX and SME do cache flushing during kexec by
making a percpu boolean control whether to do the WBINVD.
-- Background --
On SME platforms, dirty cacheline aliases with and without encryption
bit can coexist, and the CPU can flush them back to memory in random
order. During kexec, the caches must be flushed before jumping to the
new kernel otherwise the dirty cachelines could silently corrupt the
memory used by the new kernel due to different encryption property.
TDX also needs a cache flush during kexec for the same reason. It would
be good to have a generic way to flush the cache instead of scattering
checks for each feature all around.
When SME is enabled, the kernel basically encrypts all memory including
the kernel itself and a simple memory write from the kernel could dirty
cachelines. Currently, the kernel uses WBINVD to flush the cache for
SME during kexec in two places:
1) the one in stop_this_cpu() for all remote CPUs when the kexec-ing CPU
stops them;
2) the one in the relocate_kernel() where the kexec-ing CPU jumps to the
new kernel.
-- Solution --
Unlike SME, TDX can only dirty cachelines when it is used (i.e., when
SEAMCALLs are performed). Since there are no more SEAMCALLs after the
aforementioned WBINVDs, leverage this for TDX.
To unify the approach for SME and TDX, use a percpu boolean to indicate
the cache may be in an incoherent state and needs flushing during kexec,
and set the boolean for SME. TDX can then leverage it.
While SME could use a global flag (since it's enabled at early boot and
enabled on all CPUs), the percpu flag fits TDX better:
The percpu flag can be set when a CPU makes a SEAMCALL, and cleared when
another WBINVD on the CPU obviates the need for a kexec-time WBINVD.
Saving kexec-time WBINVD is valuable, because there is an existing
race[*] where kexec could proceed while another CPU is active. WBINVD
could make this race worse, so it's worth skipping it when possible.
-- Side effect to SME --
Today the first WBINVD in the stop_this_cpu() is performed when SME is
*supported* by the platform, and the second WBINVD is done in
relocate_kernel() when SME is *activated* by the kernel. Make things
simple by changing to do the second WBINVD when the platform supports
SME. This allows the kernel to simply turn on this percpu boolean when
bringing up a CPU by checking whether the platform supports SME.
No other functional change intended.
[*] The aforementioned race:
During kexec native_stop_other_cpus() is called to stop all remote CPUs
before jumping to the new kernel. native_stop_other_cpus() firstly
sends normal REBOOT vector IPIs to stop remote CPUs and waits them to
stop. If that times out, it sends NMI to stop the CPUs that are still
alive. The race happens when native_stop_other_cpus() has to send NMIs
and could potentially result in the system hang (for more information
please see [1]).
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/kvm/b963fcd60abe26c7ec5dc20b42f1a2ebbcc72397.1750934177.git.kai.huang@intel.com/ [1]
Link: https://lore.kernel.org/all/20250901160930.1785244-3-pbonzini%40redhat.com
During kexec, the kernel jumps to the new kernel in relocate_kernel(),
which is implemented in assembly and both 32-bit and 64-bit have their
own version.
Currently, for both 32-bit and 64-bit, the last two parameters of the
relocate_kernel() are both 'unsigned int' but actually they only convey
a boolean, i.e., one bit information. The 'unsigned int' has enough
space to carry two bits information therefore there's no need to pass
the two booleans in two separate 'unsigned int'.
Consolidate the last two function parameters of relocate_kernel() into a
single 'unsigned int' and pass flags instead.
Only consolidate the 64-bit version albeit the similar optimization can
be done for the 32-bit version too. Don't bother changing the 32-bit
version while it is working (since assembly code change is required).
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/all/20250901160930.1785244-2-pbonzini%40redhat.com
Validate that all indirect calls adhere to kCFI rules. Notably doing
nocfi indirect call to a cfi function is broken.
Apparently some Rust 'core' code violates this and explodes when ran
with FineIBT.
All the ANNOTATE_NOCFI_SYM sites are prime targets for attackers.
- runtime EFI is especially henous because it also needs to disable
IBT. Basically calling unknown code without CFI protection at
runtime is a massice security issue.
- Kexec image handover; if you can exploit this, you get to keep it :-)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lkml.kernel.org/r/20250714103441.496787279@infradead.org
semaphore" from Lance Yang enhances the hung task detector. The
detector presently dumps the blocking tasks's stack when it is blocked
on a mutex. Lance's series extends this to semaphores.
- The 2 patch series "nilfs2: improve sanity checks in dirty state
propagation" from Wentao Liang addresses a couple of minor flaws in
nilfs2.
- The 2 patch series "scripts/gdb: Fixes related to lx_per_cpu()" from
Illia Ostapyshyn fixes a couple of issues in the gdb scripts.
- The 9 patch series "Support kdump with LUKS encryption by reusing LUKS
volume keys" from Coiby Xu addresses a usability problem with kdump.
When the dump device is LUKS-encrypted, the kdump kernel may not have
the keys to the encrypted filesystem. A full writeup of this is in the
series [0/N] cover letter.
- The 2 patch series "sysfs: add counters for lockups and stalls" from
Max Kellermann adds /sys/kernel/hardlockup_count and
/sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count.
- The 3 patch series "fork: Page operation cleanups in the fork code"
from Pasha Tatashin implements a number of code cleanups in fork.c.
- The 3 patch series "scripts/gdb/symbols: determine KASLR offset on
s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in
the gdb scripts.
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Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "hung_task: extend blocking task stacktrace dump to semaphore" from
Lance Yang enhances the hung task detector.
The detector presently dumps the blocking tasks's stack when it is
blocked on a mutex. Lance's series extends this to semaphores
- "nilfs2: improve sanity checks in dirty state propagation" from
Wentao Liang addresses a couple of minor flaws in nilfs2
- "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn
fixes a couple of issues in the gdb scripts
- "Support kdump with LUKS encryption by reusing LUKS volume keys" from
Coiby Xu addresses a usability problem with kdump.
When the dump device is LUKS-encrypted, the kdump kernel may not have
the keys to the encrypted filesystem. A full writeup of this is in
the series [0/N] cover letter
- "sysfs: add counters for lockups and stalls" from Max Kellermann adds
/sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and
/sys/kernel/rcu_stall_count
- "fork: Page operation cleanups in the fork code" from Pasha Tatashin
implements a number of code cleanups in fork.c
- "scripts/gdb/symbols: determine KASLR offset on s390 during early
boot" from Ilya Leoshkevich fixes some s390 issues in the gdb
scripts
* tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits)
llist: make llist_add_batch() a static inline
delayacct: remove redundant code and adjust indentation
squashfs: add optional full compressed block caching
crash_dump, nvme: select CONFIGFS_FS as built-in
scripts/gdb/symbols: determine KASLR offset on s390 during early boot
scripts/gdb/symbols: factor out pagination_off()
scripts/gdb/symbols: factor out get_vmlinux()
kernel/panic.c: format kernel-doc comments
mailmap: update and consolidate Casey Connolly's name and email
nilfs2: remove wbc->for_reclaim handling
fork: define a local GFP_VMAP_STACK
fork: check charging success before zeroing stack
fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
fork: clean-up ifdef logic around stack allocation
kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count
kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count
x86/crash: make the page that stores the dm crypt keys inaccessible
x86/crash: pass dm crypt keys to kdump kernel
Revert "x86/mm: Remove unused __set_memory_prot()"
crash_dump: retrieve dm crypt keys in kdump kernel
...
This adds an addition layer of protection for the saved copy of dm crypt
key. Trying to access the saved copy will cause page fault.
Link: https://lkml.kernel.org/r/20250502011246.99238-9-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Suggested-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reduce the window during which exceptions are unhandled, by leaving the
GDT/IDT in place all the way into the relocate_kernel() function, until
the moment that %cr3 gets replaced.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250326142404.256980-4-dwmw2@infradead.org
This supports the same 32-bit MMIO-mapped 8250 as the early_printk code.
It's not clear why the early_printk code supports this form and only this
form; the actual runtime 8250_pci doesn't seem to support it. But having
hacked up QEMU to expose such a device, early_printk does work with it,
and now so does the kexec debug code.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250326142404.256980-3-dwmw2@infradead.org
Both i386 and x86_64 now copy the relocate_kernel() function into the control
page and execute it from there, using an open-coded function pointer.
Use a typedef for it instead.
[ bp: Put relocate_kernel_ptr ptr arithmetic on a single line. ]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250109140757.2841269-10-dwmw2@infradead.org
A recent commit caused the relocate_kernel() function to be invoked through
a function pointer, but it does not have CFI information. The resulting trap
occurs after the IDT and GDT have been invalidated, leading to a triple-fault
if CONFIG_CFI_CLANG is enabled.
Using SYM_TYPED_FUNC_START() to provide the CFI information looks like it will
require a prolonged battle with objtool. And is fairly pointless anyway, as
the actual signature comes from a __kcfi_typeid_… symbol emitted from the
C code based on the function prototype it thinks that relocate_kernel has,
rendering the check somewhat tautological.
The simple fix is just to mark machine_kexec() with __nocfi.
Fixes: eeebbde571 ("x86/kexec: Invoke copy of relocate_kernel() instead of the original")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250109140757.2841269-7-dwmw2@infradead.org
All writes to the page now happen before it gets marked as executable
(or after it's already switched to the identmap page tables where it's
OK to be RWX).
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20241205153343.3275139-14-dwmw2@infradead.org
The kernel's virtual mapping of the relocate_kernel page currently needs
to be RWX because it is written to before the %cr3 switch.
Now that the relocate_kernel page has its own .data section and local
variables, it can also have *global* variables. So eliminate the separate
page_list argument, and write the same information directly to variables
in the relocate_kernel page instead. This way, the relocate_kernel code
itself doesn't need to copy it.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-11-dwmw2@infradead.org
Now that the relocate_kernel page is handled sanely by a linker script
we can have actual data, and just use %rip-relative addressing to access
it.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-10-dwmw2@infradead.org
Now that the copy is executed instead of the original, the relocate_kernel
page can live in the kernel's .text section. This will allow subsequent
commits to actually add real data to it and clean up the code somewhat as
well as making the control page ROX.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-9-dwmw2@infradead.org
This currently calls set_memory_x() from machine_kexec_prepare() just
like the 32-bit version does. That's actually a bit earlier than I'd
like, as it leaves the page RWX all the time the image is even *loaded*.
Subsequent commits will eliminate all the writes to the page between the
point it's marked executable in machine_kexec_prepare() the time that
relocate_kernel() is running and has switched to the identmap %cr3, so
that it can be ROX. But that can't happen until it's moved to the .data
section of the kernel, and *that* can't happen until we start executing
the copy instead of executing it in place in the kernel .text. So break
the circular dependency in those commits by letting it be RWX for now.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-8-dwmw2@infradead.org
There's no need for this to wait until the actual machine_kexec() invocation;
future changes will need to make the control page read-only and executable,
so all writes should be completed before machine_kexec_prepare() returns.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-7-dwmw2@infradead.org
Now that the following fix:
d0ceea662d ("x86/mm: Add _PAGE_NOPTISHADOW bit to avoid updating userspace page tables")
stops kernel_ident_mapping_init() from scribbling over the end of a
4KiB PGD by assuming the following 4KiB will be a userspace PGD,
there's no good reason for the kexec PGD to be part of a single
8KiB allocation with the control_code_page.
( It's not clear that that was the reason for x86_64 kexec doing it that
way in the first place either; there were no comments to that effect and
it seems to have been the case even before PTI came along. It looks like
it was just a happy accident which prevented memory corruption on kexec. )
Either way, it definitely isn't needed now. Just allocate the PGD
separately on x86_64, like i386 already does.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-6-dwmw2@infradead.org
A kexec kernel boot failure is sometimes observed on AMD CPUs due to an
unmapped EFI config table array. This can be seen when "nogbpages" is on
the kernel command line, and has been observed as a full BIOS reboot rather
than a successful kexec.
This was also the cause of reported regressions attributed to Commit
7143c5f4cf20 ("x86/mm/ident_map: Use gbpages only where full GB page should
be mapped.") which was subsequently reverted.
To avoid this page fault, explicitly include the EFI config table array in
the kexec identity map.
Further explanation:
The following 2 commits caused the EFI config table array to be
accessed when enabling sev at kernel startup.
commit ec1c66af3a ("x86/compressed/64: Detect/setup SEV/SME features
earlier during boot")
commit c01fce9cef ("x86/compressed: Add SEV-SNP feature
detection/setup")
This is in the code that examines whether SEV should be enabled or not, so
it can even affect systems that are not SEV capable.
This may result in a page fault if the EFI config table array's address is
unmapped. Since the page fault occurs before the new kernel establishes its
own identity map and page fault routines, it is unrecoverable and kexec
fails.
Most often, this problem is not seen because the EFI config table array
gets included in the map by the luck of being placed at a memory address
close enough to other memory areas that *are* included in the map created
by kexec.
Both the "nogbpages" command line option and the "use gpbages only where
full GB page should be mapped" change greatly reduce the chance of being
included in the map by luck, which is why the problem appears.
Signed-off-by: Tao Liu <ltao@redhat.com>
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Pavin Joseph <me@pavinjoseph.com>
Tested-by: Sarah Brofeldt <srhb@dbc.dk>
Tested-by: Eric Hagberg <ehagberg@gmail.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/all/20240717213121.3064030-2-steve.wahl@hpe.com
The call to cc_platform_has() triggers a fault and system crash if call depth
tracking is active because the GS segment has been reset by load_segments() and
GS_BASE is now 0 but call depth tracking uses per-CPU variables to operate.
Call cc_platform_has() earlier in the function when GS is still valid.
[ bp: Massage. ]
Fixes: 5d8213864a ("x86/retbleed: Add SKL return thunk")
Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20240603083036.637-1-bp@kernel.org
Now crash codes under kernel/ folder has been split out from kexec
code, crash dumping can be separated from kexec reboot in config
items on x86 with some adjustments.
Here, also change some ifdefs or IS_ENABLED() check to more appropriate
ones, e,g
- #ifdef CONFIG_KEXEC_CORE -> #ifdef CONFIG_CRASH_DUMP
- (!IS_ENABLED(CONFIG_KEXEC_CORE)) - > (!IS_ENABLED(CONFIG_CRASH_RESERVE))
[bhe@redhat.com: don't nest CONFIG_CRASH_DUMP ifdef inside CONFIG_KEXEC_CODE ifdef scope]
Link: https://lore.kernel.org/all/SN6PR02MB4157931105FA68D72E3D3DB8D47B2@SN6PR02MB4157.namprd02.prod.outlook.com/T/#u
Link: https://lkml.kernel.org/r/20240124051254.67105-7-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kernel_ident_mapping_init() takes an exclusive memory range [pstart, pend)
where pend is not included in the range, while res represents an inclusive
memory range [start, end] where end is considered part of the range.
Passing [start, end] rather than [start, end+1) to
kernel_ident_mapping_init() may result in the identity mapping for the
end address not being set up.
For example, when res->start is equal to res->end,
kernel_ident_mapping_init() will not establish any identity mapping.
Similarly, when the value of res->end is a multiple of 2M and the page
table maps 2M pages, kernel_ident_mapping_init() will also not set up
identity mapping for res->end.
Therefore, passing res->end directly to kernel_ident_mapping_init() is
incorrect, the correct end address should be `res->end + 1`.
Link: https://lkml.kernel.org/r/20231221101702.20956-1-ytcoode@gmail.com
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The expression `mstart + resource_size(res) - 1` is actually equivalent to
`res->end`, simplify the logic of this function to improve readability.
Link: https://lkml.kernel.org/r/20231212150506.31711-1-ytcoode@gmail.com
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kexec: Remove unnecessary arch hook", v2.
There are no arch-specific things in arch_kexec_kernel_image_load(), so
remove it and just use the generic version.
This patch (of 2):
The x86 implementation of arch_kexec_kernel_image_load() is functionally
identical to the generic arch_kexec_kernel_image_load():
arch_kexec_kernel_image_load # x86
if (!image->fops || !image->fops->load)
return ERR_PTR(-ENOEXEC);
return image->fops->load(image, image->kernel_buf, ...)
arch_kexec_kernel_image_load # generic
kexec_image_load_default
if (!image->fops || !image->fops->load)
return ERR_PTR(-ENOEXEC);
return image->fops->load(image, image->kernel_buf, ...)
Remove the x86-specific version and use the generic
arch_kexec_kernel_image_load(). No functional change intended.
Link: https://lkml.kernel.org/r/20230307224416.907040-1-helgaas@kernel.org
Link: https://lkml.kernel.org/r/20230307224416.907040-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This is reported by kmemleak detector:
unreferenced object 0xffffc900002a9000 (size 4096):
comm "kexec", pid 14950, jiffies 4295110793 (age 373.951s)
hex dump (first 32 bytes):
7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 .ELF............
04 00 3e 00 01 00 00 00 00 00 00 00 00 00 00 00 ..>.............
backtrace:
[<0000000016a8ef9f>] __vmalloc_node_range+0x101/0x170
[<000000002b66b6c0>] __vmalloc_node+0xb4/0x160
[<00000000ad40107d>] crash_prepare_elf64_headers+0x8e/0xcd0
[<0000000019afff23>] crash_load_segments+0x260/0x470
[<0000000019ebe95c>] bzImage64_load+0x814/0xad0
[<0000000093e16b05>] arch_kexec_kernel_image_load+0x1be/0x2a0
[<000000009ef2fc88>] kimage_file_alloc_init+0x2ec/0x5a0
[<0000000038f5a97a>] __do_sys_kexec_file_load+0x28d/0x530
[<0000000087c19992>] do_syscall_64+0x3b/0x90
[<0000000066e063a4>] entry_SYSCALL_64_after_hwframe+0x44/0xae
In crash_prepare_elf64_headers(), a buffer is allocated via vmalloc() to
store elf headers. While it's not freed back to system correctly when
kdump kernel is reloaded or unloaded. Then memory leak is caused. Fix it
by introducing x86 specific function arch_kimage_file_post_load_cleanup(),
and freeing the buffer there.
And also remove the incorrect elf header buffer freeing code. Before
calling arch specific kexec_file loading function, the image instance has
been initialized. So 'image->elf_headers' must be NULL. It doesn't make
sense to free the elf header buffer in the place.
Three different people have reported three bugs about the memory leak on
x86_64 inside Redhat.
Link: https://lkml.kernel.org/r/20220223113225.63106-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace uses of sev_active() with the more generic cc_platform_has()
using CC_ATTR_GUEST_MEM_ENCRYPT. If future support is added for other
memory encryption technologies, the use of CC_ATTR_GUEST_MEM_ENCRYPT
can be updated, as required.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210928191009.32551-7-bp@alien8.de
Replace uses of sme_active() with the more generic cc_platform_has()
using CC_ATTR_HOST_MEM_ENCRYPT. If future support is added for other
memory encryption technologies, the use of CC_ATTR_HOST_MEM_ENCRYPT
can be updated, as required.
This also replaces two usages of sev_active() that are really geared
towards detecting if SME is active.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210928191009.32551-6-bp@alien8.de
These files contain private set_gdt() functions which are only used to
invalid the gdt; machine_kexec_64.c also contains a set_idt()
function to invalidate the idt.
phys_to_virt(0) *really* doesn't make any sense for creating an
invalid GDT. A NULL pointer (virtual 0) makes a lot more sense;
although neither will allow any actual memory reference, a NULL
pointer stands out more.
Replace these calls with native_[gi]dt_invalidate().
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210519212154.511983-7-hpa@zytor.com
- Refactoring powerpc and arm64 kexec DT handling to common code. This
enables IMA on arm64.
- Add kbuild support for applying DT overlays at build time. The first
user are the DT unittests.
- Fix kerneldoc formatting and W=1 warnings in drivers/of/
- Fix handling 64-bit flag on PCI resources
- Bump dtschema version required to v2021.2.1
- Enable undocumented compatible checks for dtbs_check. This allows
tracking of missing binding schemas.
- DT docs improvements. Regroup the DT docs and add the example schema
and DT kernel ABI docs to the doc build.
- Convert Broadcom Bluetooth and video-mux bindings to schema
- Add QCom sm8250 Venus video codec binding schema
- Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile
Technologies Inc.
- Cleanup of DT schema type references on common properties and
standard unit properties
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Merge tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Refactor powerpc and arm64 kexec DT handling to common code. This
enables IMA on arm64.
- Add kbuild support for applying DT overlays at build time. The first
user are the DT unittests.
- Fix kerneldoc formatting and W=1 warnings in drivers/of/
- Fix handling 64-bit flag on PCI resources
- Bump dtschema version required to v2021.2.1
- Enable undocumented compatible checks for dtbs_check. This allows
tracking of missing binding schemas.
- DT docs improvements. Regroup the DT docs and add the example schema
and DT kernel ABI docs to the doc build.
- Convert Broadcom Bluetooth and video-mux bindings to schema
- Add QCom sm8250 Venus video codec binding schema
- Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile
Technologies Inc.
- Cleanup of DT schema type references on common properties and
standard unit properties
* tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits)
powerpc: If kexec_build_elf_info() fails return immediately from elf64_load()
powerpc: Free fdt on error in elf64_load()
of: overlay: Fix kerneldoc warning in of_overlay_remove()
of: linux/of.h: fix kernel-doc warnings
of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses
dt-bindings: bcm4329-fmac: add optional brcm,ccode-map
docs: dt: update writing-schema.rst references
dt-bindings: media: venus: Add sm8250 dt schema
of: base: Fix spelling issue with function param 'prop'
docs: dt: Add DT API documentation
of: Add missing 'Return' section in kerneldoc comments
of: Fix kerneldoc output formatting
docs: dt: Group DT docs into relevant sub-sections
docs: dt: Make 'Devicetree' wording more consistent
docs: dt: writing-schema: Include the example schema in the doc build
docs: dt: writing-schema: Remove spurious indentation
dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc
dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3
dt-bindings: media: video-interfaces: Drop the example
devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt
...
Fix ~144 single-word typos in arch/x86/ code comments.
Doing this in a single commit should reduce the churn.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-kernel@vger.kernel.org
ELF related fields elf_headers, elf_headers_sz, and elf_load_addr
have been moved from 'struct kimage_arch' to 'struct kimage'.
Use the ELF fields defined in 'struct kimage'.
Suggested-by: Rob Herring <robh@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-5-nramas@linux.microsoft.com
Patch series "mm: consolidate definitions of page table accessors", v2.
The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.
Most of these definitions are actually identical and typically it boils
down to, e.g.
static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}
These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.
For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.
These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.
This patch (of 12):
The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.
The include statements in such cases are remove with a simple loop:
for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On x86 kernels configured with CONFIG_PROC_KCORE=y and
CONFIG_KEXEC_CORE=n, the vmcoreinfo note in /proc/kcore is incomplete.
Specifically, it is missing arch-specific information like the KASLR
offset and whether 5-level page tables are enabled. This breaks
applications like drgn [1] and crash [2], which need this information
for live debugging via /proc/kcore.
This happens because:
1. CONFIG_PROC_KCORE selects CONFIG_CRASH_CORE.
2. kernel/crash_core.c (compiled if CONFIG_CRASH_CORE=y) calls
arch_crash_save_vmcoreinfo() to get the arch-specific parts of
vmcoreinfo. If it is not defined, then it uses a no-op fallback.
3. x86 defines arch_crash_save_vmcoreinfo() in
arch/x86/kernel/machine_kexec_*.c, which is only compiled if
CONFIG_KEXEC_CORE=y.
Therefore, an x86 kernel with CONFIG_CRASH_CORE=y and
CONFIG_KEXEC_CORE=n uses the no-op fallback and gets incomplete
vmcoreinfo data. This isn't relevant to kdump, which requires
CONFIG_KEXEC_CORE. It only affects applications which read vmcoreinfo at
runtime, like the ones mentioned above.
Fix it by moving arch_crash_save_vmcoreinfo() into two new
arch/x86/kernel/crash_core_*.c files, which are gated behind
CONFIG_CRASH_CORE.
1: 73dd7def12/libdrgn/program.c (L385)
2: 60a42d7092
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/0589961254102cca23e3618b96541b89f2b249e2.1576858905.git.osandov@fb.com
When the crashkernel kernel command line option is specified, the low
1M memory will always be reserved now. Therefore, it's not necessary to
create a backup region anymore and also no need to copy the contents of
the first 640k to it.
Remove all the code related to handling that backup region.
[ bp: Massage commit message. ]
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: bhe@redhat.com
Cc: Dave Young <dyoung@redhat.com>
Cc: d.hatayama@fujitsu.com
Cc: dhowells@redhat.com
Cc: ebiederm@xmission.com
Cc: horms@verge.net.au
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jürgen Gross <jgross@suse.com>
Cc: kexec@lists.infradead.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: vgoyal@redhat.com
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191108090027.11082-3-lijiang@redhat.com
Pull x865 kdump updates from Thomas Gleixner:
"Yet more kexec/kdump updates:
- Properly support kexec when AMD's memory encryption (SME) is
enabled
- Pass reserved e820 ranges to the kexec kernel so both PCI and SME
can work"
* 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
fs/proc/vmcore: Enable dumping of encrypted memory when SEV was active
x86/kexec: Set the C-bit in the identity map page table when SEV is active
x86/kexec: Do not map kexec area as decrypted when SEV is active
x86/crash: Add e820 reserved ranges to kdump kernel's e820 table
x86/mm: Rework ioremap resource mapping determination
x86/e820, ioport: Add a new I/O resource descriptor IORES_DESC_RESERVED
x86/mm: Create a workarea in the kernel for SME early encryption
x86/mm: Identify the end of the kernel area to be reserved
Pull x86 boot updates from Thomas Gleixner:
"Assorted updates to kexec/kdump:
- Proper kexec support for 4/5-level paging and jumping from a
5-level to a 4-level paging kernel.
- Make the EFI support for kexec/kdump more robust
- Enforce that the GDT is properly aligned instead of getting the
alignment by chance"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kdump/64: Restrict kdump kernel reservation to <64TB
x86/kexec/64: Prevent kexec from 5-level paging to a 4-level only kernel
x86/boot: Add xloadflags bits to check for 5-level paging support
x86/boot: Make the GDT 8-byte aligned
x86/kexec: Add the ACPI NVS region to the ident map
x86/boot: Call get_rsdp_addr() after console_init()
Revert "x86/boot: Disable RSDP parsing temporarily"
x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels
x86/kexec: Add the EFI system tables and ACPI tables to the ident map
When SEV is active, the second kernel image is loaded into encrypted
memory. For that, make sure that when kexec builds the identity mapping
page table, the memory is encrypted (i.e., _PAGE_ENC is set).
[ bp: Sort local args and OR in _PAGE_ENC for more clarity. ]
Co-developed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: bhe@redhat.com
Cc: dyoung@redhat.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kexec@lists.infradead.org
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190430074421.7852-3-lijiang@redhat.com
When a virtual machine panics, its memory needs to be dumped for
analysis. With memory encryption in the picture, special care must be
taken when loading a kexec/kdump kernel in a SEV guest.
A SEV guest starts and runs fully encrypted. In order to load a kexec
kernel and initrd, arch_kexec_post_{alloc,free}_pages() need to not map
areas as decrypted unconditionally but differentiate whether the kernel
is running as a SEV guest and if so, leave kexec area encrypted.
[ bp: Reduce commit message to the relevant information pertaining to
this commit only. ]
Co-developed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: bhe@redhat.com
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: dyoung@redhat.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kexec@lists.infradead.org
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190430074421.7852-2-lijiang@redhat.com
Based on 2 normalized pattern(s):
this source code is licensed under the gnu general public license
version 2 see the file copying for more details
this source code is licensed under general public license version 2
see
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 52 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.449021192@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the recent addition of RSDP parsing in the decompression stage,
a kexec-ed kernel now needs ACPI tables to be covered by the identity
mapping. And in commit
6bbeb276b7 ("x86/kexec: Add the EFI system tables and ACPI tables to the ident map")
the ACPI tables memory region was added to the ident map.
But some machines have only an ACPI NVS memory region and the ACPI
tables are located in that region. In such case, the kexec-ed kernel
will still fail when trying to access ACPI tables if they're not mapped.
So add the NVS memory region to the ident map as well.
[ bp: Massage. ]
Fixes: 6bbeb276b7 ("x86/kexec: Add the EFI system tables and ACPI tables to the ident map")
Suggested-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chao Fan <fanc.fnst@cn.fujitsu.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: kexec@lists.infradead.org
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190610073617.19767-1-kasong@redhat.com
Currently, only the whole physical memory is identity-mapped for the
kexec kernel and the regions reserved by firmware are ignored.
However, the recent addition of RSDP parsing in the decompression stage
and especially:
33f0df8d84 ("x86/boot: Search for RSDP in the EFI tables")
which tries to access EFI system tables and to dig out the RDSP address
from there, becomes a problem because in certain configurations, they
might not be mapped in the kexec'ed kernel's address space.
What is more, this problem doesn't appear on all systems because the
kexec kernel uses gigabyte pages to build the identity mapping. And
the EFI system tables and ACPI tables can, depending on the system
configuration, end up being mapped as part of all physical memory, if
they share the same 1 GB area with the physical memory.
Therefore, make sure they're always mapped.
[ bp: productize half-baked patch:
- rewrite commit message.
- correct the map_acpi_tables() function name in the !ACPI case. ]
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Cc: dyoung@redhat.com
Cc: fanc.fnst@cn.fujitsu.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: j-nomura@ce.jp.nec.com
Cc: kexec@lists.infradead.org
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190429002318.GA25400@MiWiFi-R3L-srv
On AMD SME machines, makedumpfile tools need to know whether the crashed
kernel was encrypted.
If SME is enabled in the first kernel, the crashed kernel's page table
entries (pgd/pud/pmd/pte) contain the memory encryption mask which
makedumpfile needs to remove in order to obtain the true physical
address.
Export that mask in a vmcoreinfo variable.
[ bp: Massage commit message and move define at the end of the
function. ]
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: anderson@redhat.com
Cc: k-hagio@ab.jp.nec.com
Cc: kexec@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190110121944.6050-3-lijiang@redhat.com
pgtable_l5_enabled is defined using cpu_feature_enabled() but we refer
to it as a variable. This is misleading.
Make pgtable_l5_enabled() a function.
We cannot literally define it as a function due to circular dependencies
between header files. Function-alike macros is close enough.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180518103528.59260-4-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
>From ff82bedd3e12f0d3353282054ae48c3bd8c72012 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Wed, 9 May 2018 12:12:39 +0900
Subject: [PATCH v3] x86/kexec: avoid double free_page() upon do_kexec_load() failure.
syzbot is reporting crashes after memory allocation failure inside
do_kexec_load() [1]. This is because free_transition_pgtable() is called
by both init_transition_pgtable() and machine_kexec_cleanup() when memory
allocation failed inside init_transition_pgtable().
Regarding 32bit code, machine_kexec_free_page_tables() is called by both
machine_kexec_alloc_page_tables() and machine_kexec_cleanup() when memory
allocation failed inside machine_kexec_alloc_page_tables().
Fix this by leaving the error handling to machine_kexec_cleanup()
(and optionally setting NULL after free_page()).
[1] https://syzkaller.appspot.com/bug?id=91e52396168cf2bdd572fe1e1bc0bc645c1c6b40
Fixes: f5deb79679 ("x86: kexec: Use one page table in x86_64 machine_kexec")
Fixes: 92be3d6bdf ("kexec/i386: allocate page table pages dynamically")
Reported-by: syzbot <syzbot+d96f60296ef613fe1d69@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: prudo@linux.vnet.ibm.com
Cc: Huang Ying <ying.huang@intel.com>
Cc: syzkaller-bugs@googlegroups.com
Cc: takahiro.akashi@linaro.org
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: akpm@linux-foundation.org
Cc: dyoung@redhat.com
Cc: kirill.shutemov@linux.intel.com
Link: https://lkml.kernel.org/r/201805091942.DGG12448.tMFVFSJFQOOLHO@I-love.SAKURA.ne.jp
The current code uses the sh_offset field in purgatory_info->sechdrs to
store a pointer to the current load address of the section. Depending
whether the section will be loaded or not this is either a pointer into
purgatory_info->purgatory_buf or kexec_purgatory. This is not only a
violation of the ELF standard but also makes the code very hard to
understand as you cannot tell if the memory you are using is read-only
or not.
Remove this misuse and store the offset of the section in
pugaroty_info->purgatory_buf in sh_offset.
Link: http://lkml.kernel.org/r/20180321112751.22196-10-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the relocations are applied to the purgatory only the section the
relocations are applied to is writable. The other sections, i.e. the
symtab and .rel/.rela, are in read-only kexec_purgatory. Highlight this
by marking the corresponding variables as 'const'.
While at it also change the signatures of arch_kexec_apply_relocations* to
take section pointers instead of just the index of the relocation section.
This removes the second lookup and sanity check of the sections in arch
code.
Link: http://lkml.kernel.org/r/20180321112751.22196-6-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As arch_kexec_kernel_image_{probe,load}(),
arch_kimage_file_post_load_cleanup() and arch_kexec_kernel_verify_sig()
are almost duplicated among architectures, they can be commonalized with
an architecture-defined kexec_file_ops array. So let's factor them out.
Link: http://lkml.kernel.org/r/20180306102303.9063-3-takahiro.akashi@linaro.org
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Dave Young <dyoung@redhat.com>
Tested-by: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
