Commit 0b631ed3ce92 ("kselftest: cpufreq: Add RTC wakeup alarm") added
support for automatic wakeup in the suspend routine of the cpufreq
kselftest by using rtcwake, however it left the manual power state
change in the common path. The end result is that when running the
cpufreq kselftest with '-t suspend_rtc' or '-t hibernate_rtc', the
system will go to sleep and be woken up by the RTC, but then immediately
go to sleep again with no wakeup programmed, so it will sleep forever in
an automated testing setup.
Fix this by moving the manual power state change so that it only happens
when not using rtcwake.
Fixes: 0b631ed3ce92 ("kselftest: cpufreq: Add RTC wakeup alarm")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com>
---
tools/testing/selftests/cpufreq/cpufreq.sh | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/cpufreq/cpufreq.sh b/tools/testing/selftests/cpufreq/cpufreq.sh
index e350c521b4675080943d2c74dc31533979410316..3aad9db921b5339585da5711a08775ebd965aaf3 100755
--- a/tools/testing/selftests/cpufreq/cpufreq.sh
+++ b/tools/testing/selftests/cpufreq/cpufreq.sh
@@ -244,9 +244,10 @@ do_suspend()
printf "Failed to suspend using RTC wake alarm\n"
return 1
fi
+ else
+ echo $filename > $SYSFS/power/state
fi
- echo $filename > $SYSFS/power/state
printf "Came out of $1\n"
printf "Do basic tests after finishing $1 to verify cpufreq state\n\n"
---
base-commit: 8a2d53ce3c5f82683ad3df9a9a55822816fe64e7
change-id: 20250429-ksft-cpufreq-suspend-rtc-double-fix-75c560e1a30f
Best regards,
--
Nícolas F. R. A. Prado <nfraprado(a)collabora.com>
Misbehaving guests can cause bus locks to degrade the performance of
a system. Non-WB (write-back) and misaligned locked RMW (read-modify-write)
instructions are referred to as "bus locks" and require system wide
synchronization among all processors to guarantee the atomicity. The bus
locks can impose notable performance penalties for all processors within
the system.
Support for the Bus Lock Threshold is indicated by CPUID
Fn8000_000A_EDX[29] BusLockThreshold=1, the VMCB provides a Bus Lock
Threshold enable bit and an unsigned 16-bit Bus Lock Threshold count.
VMCB intercept bit
VMCB Offset Bits Function
14h 5 Intercept bus lock operations
Bus lock threshold count
VMCB Offset Bits Function
120h 15:0 Bus lock counter
During VMRUN, the bus lock threshold count is fetched and stored in an
internal count register. Prior to executing a bus lock within the guest,
the processor verifies the count in the bus lock register. If the count is
greater than zero, the processor executes the bus lock, reducing the count.
However, if the count is zero, the bus lock operation is not performed, and
instead, a Bus Lock Threshold #VMEXIT is triggered to transfer control to
the Virtual Machine Monitor (VMM).
A Bus Lock Threshold #VMEXIT is reported to the VMM with VMEXIT code 0xA5h,
VMEXIT_BUSLOCK. EXITINFO1 and EXITINFO2 are set to 0 on a VMEXIT_BUSLOCK.
On a #VMEXIT, the processor writes the current value of the Bus Lock
Threshold Counter to the VMCB.
Note: Currently, virtualizing the Bus Lock Threshold feature for L1 guest is
not supported.
More details about the Bus Lock Threshold feature can be found in AMD APM
[1].
v3 -> v4
- Incorporated Sean's review comments
- Added a preparatory patch to move linear_rip out of kvm_pio_request, so
that it can be used by the bus lock threshold patches.
- Added complete_userspace_buslock() function to reload bus_lock_counter
to '1' only if the usespace has not changed the RIP.
- Added changes to continue running bus_lock_counter accross the nested
transitions.
v2 -> v3
- Drop parch to add virt tag in /proc/cpuinfo.
- Incorporated Tom's review comments.
v1 -> v2
- Incorporated misc review comments from Sean.
- Removed bus_lock_counter module parameter.
- Set the value of bus_lock_counter to zero by default and reload the value by 1
in bus lock exit handler.
- Add documentation for the behavioral difference for KVM_EXIT_BUS_LOCK.
- Improved selftest for buslock to work on SVM and VMX.
- Rewrite the commit messages.
Patches are prepared on kvm-next/next (c9ea48bb6ee6).
Testing done:
- Tested the Bus Lock Threshold functionality on normal, SEV, SEV-ES and SEV-SNP guests.
- Tested the Bus Lock Threshold functionality on nested guests.
v1: https://lore.kernel.org/kvm/20240709175145.9986-4-manali.shukla@amd.com/T/
v2: https://lore.kernel.org/kvm/20241001063413.687787-4-manali.shukla@amd.com/T/
v3: https://lore.kernel.org/kvm/20241004053341.5726-1-manali.shukla@amd.com/T/
[1]: AMD64 Architecture Programmer's Manual Pub. 24593, April 2024,
Vol 2, 15.14.5 Bus Lock Threshold.
https://bugzilla.kernel.org/attachment.cgi?id=306250
Manali Shukla (3):
KVM: x86: Preparatory patch to move linear_rip out of kvm_pio_request
x86/cpufeatures: Add CPUID feature bit for the Bus Lock Threshold
KVM: SVM: Add support for KVM_CAP_X86_BUS_LOCK_EXIT on SVM CPUs
Nikunj A Dadhania (2):
KVM: SVM: Enable Bus lock threshold exit
KVM: selftests: Add bus lock exit test
Documentation/virt/kvm/api.rst | 19 +++
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/include/asm/svm.h | 5 +-
arch/x86/include/uapi/asm/svm.h | 2 +
arch/x86/kvm/svm/nested.c | 42 ++++++
arch/x86/kvm/svm/svm.c | 38 +++++
arch/x86/kvm/svm/svm.h | 2 +
arch/x86/kvm/x86.c | 8 +-
tools/testing/selftests/kvm/Makefile.kvm | 1 +
.../selftests/kvm/x86/kvm_buslock_test.c | 135 ++++++++++++++++++
11 files changed, 249 insertions(+), 6 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86/kvm_buslock_test.c
base-commit: c9ea48bb6ee6b28bbc956c1e8af98044618fed5e
--
2.34.1
This is the initial import of a CAN selftest from can-tests[1] into the
tree. For now, it is just a single test but when agreed on the
structure, we intend to import more tests from can-tests and add
additional test cases.
The goal of moving the CAN selftests into the tree is to align the tests
more closely with the kernel, improve testing of CAN in general, and to
simplify running the tests automatically in the various kernel CI
systems.
I have cc'ed netdev and its reviewers and maintainers to make sure they
are okay with the location of the tests and the changes to the paths in
MAINTAINERS. The changes should be merged through linux-can-next and
subsequent changes will not go to netdev anymore.
[1]: https://github.com/linux-can/can-tests
Felix Maurer (4):
selftests: can: Import tst-filter from can-tests
selftests: can: use kselftest harness in test_raw_filter
selftests: can: Use fixtures in test_raw_filter
selftests: can: Document test_raw_filter test cases
MAINTAINERS | 2 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/net/can/.gitignore | 2 +
tools/testing/selftests/net/can/Makefile | 11 +
.../selftests/net/can/test_raw_filter.c | 338 ++++++++++++++++++
.../selftests/net/can/test_raw_filter.sh | 37 ++
6 files changed, 391 insertions(+)
create mode 100644 tools/testing/selftests/net/can/.gitignore
create mode 100644 tools/testing/selftests/net/can/Makefile
create mode 100644 tools/testing/selftests/net/can/test_raw_filter.c
create mode 100755 tools/testing/selftests/net/can/test_raw_filter.sh
--
2.49.0
This series improves the following tests.
1. Get-reg-list : Adds vector support
2. SBI PMU test : Distinguish between different types of illegal exception
The first patch is just helper patch that adds stval support during
exception handling.
Signed-off-by: Atish Patra <atishp(a)rivosinc.com>
---
Changes in v2:
- Rebased on top of Linux 6.15-rc4
- Changed from ex_regs to pt_regs based on Drew's suggestion.
- Dropped Anup's review on PATCH1 as it is significantly changed from last review.
- Moved the instruction decoding macros to a common header file.
- Improved the vector reg list test as per the feedback.
- Link to v1: https://lore.kernel.org/r/20250324-kvm_selftest_improve-v1-0-583620219d4f@r…
---
Atish Patra (3):
KVM: riscv: selftests: Align the trap information wiht pt_regs
KVM: riscv: selftests: Decode stval to identify exact exception type
KVM: riscv: selftests: Add vector extension tests
.../selftests/kvm/include/riscv/processor.h | 23 ++-
tools/testing/selftests/kvm/lib/riscv/handlers.S | 164 ++++++++++++---------
tools/testing/selftests/kvm/lib/riscv/processor.c | 2 +-
tools/testing/selftests/kvm/riscv/arch_timer.c | 2 +-
tools/testing/selftests/kvm/riscv/ebreak_test.c | 2 +-
tools/testing/selftests/kvm/riscv/get-reg-list.c | 133 +++++++++++++++++
tools/testing/selftests/kvm/riscv/sbi_pmu_test.c | 24 ++-
7 files changed, 270 insertions(+), 80 deletions(-)
---
base-commit: f15d97df5afae16f40ecef942031235d1c6ba14f
change-id: 20250324-kvm_selftest_improve-9bedb9f0a6d3
--
Regards,
Atish patra
Basics and overview
===================
Software with larger attack surfaces (e.g. network facing apps like databases,
browsers or apps relying on browser runtimes) suffer from memory corruption
issues which can be utilized by attackers to bend control flow of the program
to eventually gain control (by making their payload executable). Attackers are
able to perform such attacks by leveraging call-sites which rely on indirect
calls or return sites which rely on obtaining return address from stack memory.
To mitigate such attacks, risc-v extension zicfilp enforces that all indirect
calls must land on a landing pad instruction `lpad` else cpu will raise software
check exception (a new cpu exception cause code on riscv).
Similarly for return flow, risc-v extension zicfiss extends architecture with
- `sspush` instruction to push return address on a shadow stack
- `sspopchk` instruction to pop return address from shadow stack
and compare with input operand (i.e. return address on stack)
- `sspopchk` to raise software check exception if comparision above
was a mismatch
- Protection mechanism using which shadow stack is not writeable via
regular store instructions
More information an details can be found at extensions github repo [1].
Equivalent to landing pad (zicfilp) on x86 is `ENDBRANCH` instruction in Intel
CET [3] and branch target identification (BTI) [4] on arm.
Similarly x86's Intel CET has shadow stack [5] and arm64 has guarded control
stack (GCS) [6] which are very similar to risc-v's zicfiss shadow stack.
x86 and arm64 support for user mode shadow stack is already in mainline.
Kernel awareness for user control flow integrity
================================================
This series picks up Samuel Holland's envcfg changes [2] as well. So if those are
being applied independently, they should be removed from this series.
Enabling:
In order to maintain compatibility and not break anything in user mode, kernel
doesn't enable control flow integrity cpu extensions on binary by default.
Instead exposes a prctl interface to enable, disable and lock the shadow stack
or landing pad feature for a task. This allows userspace (loader) to enumerate
if all objects in its address space are compiled with shadow stack and landing
pad support and accordingly enable the feature. Additionally if a subsequent
`dlopen` happens on a library, user mode can take a decision again to disable
the feature (if incoming library is not compiled with support) OR terminate the
task (if user mode policy is strict to have all objects in address space to be
compiled with control flow integirty cpu feature). prctl to enable shadow stack
results in allocating shadow stack from virtual memory and activating for user
address space. x86 and arm64 are also following same direction due to similar
reason(s).
clone/fork:
On clone and fork, cfi state for task is inherited by child. Shadow stack is
part of virtual memory and is a writeable memory from kernel perspective
(writeable via a restricted set of instructions aka shadow stack instructions)
Thus kernel changes ensure that this memory is converted into read-only when
fork/clone happens and COWed when fault is taken due to sspush, sspopchk or
ssamoswap. In case `CLONE_VM` is specified and shadow stack is to be enabled,
kernel will automatically allocate a shadow stack for that clone call.
map_shadow_stack:
x86 introduced `map_shadow_stack` system call to allow user space to explicitly
map shadow stack memory in its address space. It is useful to allocate shadow
for different contexts managed by a single thread (green threads or contexts)
risc-v implements this system call as well.
signal management:
If shadow stack is enabled for a task, kernel performs an asynchronous control
flow diversion to deliver the signal and eventually expects userspace to issue
sigreturn so that original execution can be resumed. Even though resume context
is prepared by kernel, it is in user space memory and is subject to memory
corruption and corruption bugs can be utilized by attacker in this race window
to perform arbitrary sigreturn and eventually bypass cfi mechanism.
Another issue is how to ensure that cfi related state on sigcontext area is not
trampled by legacy apps or apps compiled with old kernel headers.
In order to mitigate control-flow hijacting, kernel prepares a token and place
it on shadow stack before signal delivery and places address of token in
sigcontext structure. During sigreturn, kernel obtains address of token from
sigcontext struture, reads token from shadow stack and validates it and only
then allow sigreturn to succeed. Compatiblity issue is solved by adopting
dynamic sigcontext management introduced for vector extension. This series
re-factor the code little bit to allow future sigcontext management easy (as
proposed by Andy Chiu from SiFive)
config and compilation:
Introduce a new risc-v config option `CONFIG_RISCV_USER_CFI`. Selecting this
config option picks the kernel support for user control flow integrity. This
optin is presented only if toolchain has shadow stack and landing pad support.
And is on purpose guarded by toolchain support. Reason being that eventually
vDSO also needs to be compiled in with shadow stack and landing pad support.
vDSO compile patches are not included as of now because landing pad labeling
scheme is yet to settle for usermode runtime.
To get more information on kernel interactions with respect to
zicfilp and zicfiss, patch series adds documentation for
`zicfilp` and `zicfiss` in following:
Documentation/arch/riscv/zicfiss.rst
Documentation/arch/riscv/zicfilp.rst
How to test this series
=======================
Toolchain
---------
$ git clone git@github.com:sifive/riscv-gnu-toolchain.git -b cfi-dev
$ riscv-gnu-toolchain/configure --prefix=<path-to-where-to-build> --with-arch=rv64gc_zicfilp_zicfiss --enable-linux --disable-gdb --with-extra-multilib-test="rv64gc_zicfilp_zicfiss-lp64d:-static"
$ make -j$(nproc)
Qemu
----
Get the lastest qemu
$ cd qemu
$ mkdir build
$ cd build
$ ../configure --target-list=riscv64-softmmu
$ make -j$(nproc)
Opensbi
-------
$ git clone git@github.com:deepak0414/opensbi.git -b v6_cfi_spec_split_opensbi
$ make CROSS_COMPILE=<your riscv toolchain> -j$(nproc) PLATFORM=generic
Linux
-----
Running defconfig is fine. CFI is enabled by default if the toolchain
supports it.
$ make ARCH=riscv CROSS_COMPILE=<path-to-cfi-riscv-gnu-toolchain>/build/bin/riscv64-unknown-linux-gnu- -j$(nproc) defconfig
$ make ARCH=riscv CROSS_COMPILE=<path-to-cfi-riscv-gnu-toolchain>/build/bin/riscv64-unknown-linux-gnu- -j$(nproc)
In case you're building your own rootfs using toolchain, please make sure you
pick following patch to ensure that vDSO compiled with lpad and shadow stack.
"arch/riscv: compile vdso with landing pad"
Branch where above patch can be picked
https://github.com/deepak0414/linux-riscv-cfi/tree/vdso_user_cfi_v6.12-rc1
Running
-------
Modify your qemu command to have:
-bios <path-to-cfi-opensbi>/build/platform/generic/firmware/fw_dynamic.bin
-cpu rv64,zicfilp=true,zicfiss=true,zimop=true,zcmop=true
vDSO related Opens (in the flux)
=================================
I am listing these opens for laying out plan and what to expect in future
patch sets. And of course for the sake of discussion.
Shadow stack and landing pad enabling in vDSO
----------------------------------------------
vDSO must have shadow stack and landing pad support compiled in for task
to have shadow stack and landing pad support. This patch series doesn't
enable that (yet). Enabling shadow stack support in vDSO should be
straight forward (intend to do that in next versions of patch set). Enabling
landing pad support in vDSO requires some collaboration with toolchain folks
to follow a single label scheme for all object binaries. This is necessary to
ensure that all indirect call-sites are setting correct label and target landing
pads are decorated with same label scheme.
How many vDSOs
---------------
Shadow stack instructions are carved out of zimop (may be operations) and if CPU
doesn't implement zimop, they're illegal instructions. Kernel could be running on
a CPU which may or may not implement zimop. And thus kernel will have to carry 2
different vDSOs and expose the appropriate one depending on whether CPU implements
zimop or not.
References
==========
[1] - https://github.com/riscv/riscv-cfi
[2] - https://lore.kernel.org/all/20240814081126.956287-1-samuel.holland@sifive.c…
[3] - https://lwn.net/Articles/889475/
[4] - https://developer.arm.com/documentation/109576/0100/Branch-Target-Identific…
[5] - https://www.intel.com/content/dam/develop/external/us/en/documents/catc17-i…
[6] - https://lwn.net/Articles/940403/
To: Thomas Gleixner <tglx(a)linutronix.de>
To: Ingo Molnar <mingo(a)redhat.com>
To: Borislav Petkov <bp(a)alien8.de>
To: Dave Hansen <dave.hansen(a)linux.intel.com>
To: x86(a)kernel.org
To: H. Peter Anvin <hpa(a)zytor.com>
To: Andrew Morton <akpm(a)linux-foundation.org>
To: Liam R. Howlett <Liam.Howlett(a)oracle.com>
To: Vlastimil Babka <vbabka(a)suse.cz>
To: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
To: Paul Walmsley <paul.walmsley(a)sifive.com>
To: Palmer Dabbelt <palmer(a)dabbelt.com>
To: Albert Ou <aou(a)eecs.berkeley.edu>
To: Conor Dooley <conor(a)kernel.org>
To: Rob Herring <robh(a)kernel.org>
To: Krzysztof Kozlowski <krzk+dt(a)kernel.org>
To: Arnd Bergmann <arnd(a)arndb.de>
To: Christian Brauner <brauner(a)kernel.org>
To: Peter Zijlstra <peterz(a)infradead.org>
To: Oleg Nesterov <oleg(a)redhat.com>
To: Eric Biederman <ebiederm(a)xmission.com>
To: Kees Cook <kees(a)kernel.org>
To: Jonathan Corbet <corbet(a)lwn.net>
To: Shuah Khan <shuah(a)kernel.org>
To: Jann Horn <jannh(a)google.com>
To: Conor Dooley <conor+dt(a)kernel.org>
To: Miguel Ojeda <ojeda(a)kernel.org>
To: Alex Gaynor <alex.gaynor(a)gmail.com>
To: Boqun Feng <boqun.feng(a)gmail.com>
To: Gary Guo <gary(a)garyguo.net>
To: Björn Roy Baron <bjorn3_gh(a)protonmail.com>
To: Benno Lossin <benno.lossin(a)proton.me>
To: Andreas Hindborg <a.hindborg(a)kernel.org>
To: Alice Ryhl <aliceryhl(a)google.com>
To: Trevor Gross <tmgross(a)umich.edu>
Cc: linux-kernel(a)vger.kernel.org
Cc: linux-fsdevel(a)vger.kernel.org
Cc: linux-mm(a)kvack.org
Cc: linux-riscv(a)lists.infradead.org
Cc: devicetree(a)vger.kernel.org
Cc: linux-arch(a)vger.kernel.org
Cc: linux-doc(a)vger.kernel.org
Cc: linux-kselftest(a)vger.kernel.org
Cc: alistair.francis(a)wdc.com
Cc: richard.henderson(a)linaro.org
Cc: jim.shu(a)sifive.com
Cc: andybnac(a)gmail.com
Cc: kito.cheng(a)sifive.com
Cc: charlie(a)rivosinc.com
Cc: atishp(a)rivosinc.com
Cc: evan(a)rivosinc.com
Cc: cleger(a)rivosinc.com
Cc: alexghiti(a)rivosinc.com
Cc: samitolvanen(a)google.com
Cc: broonie(a)kernel.org
Cc: rick.p.edgecombe(a)intel.com
Cc: rust-for-linux(a)vger.kernel.org
changelog
---------
v14:
- rebased on top of palmer/sbi-v3. Thus dropped clement's FWFT patches
Updated RISCV_ISA_EXT_XXXX in hwcap and hwprobe constants.
- Took Radim's suggestions on bitfields.
- Placed cfi_state at the end of thread_info block so that current situation
is not disturbed with respect to member fields of thread_info in single
cacheline.
v13:
- cpu_supports_shadow_stack/cpu_supports_indirect_br_lp_instr uses
riscv_has_extension_unlikely()
- uses nops(count) to create nop slide
- RISCV_ACQUIRE_BARRIER is not needed in `amo_user_shstk`. Removed it
- changed ternaries to simply use implicit casting to convert to bool.
- kernel command line allows to disable zicfilp and zicfiss independently.
updated kernel-parameters.txt.
- ptrace user abi for cfi uses bitmasks instead of bitfields. Added ptrace
kselftest.
- cosmetic and grammatical changes to documentation.
v12:
- It seems like I had accidently squashed arch agnostic indirect branch
tracking prctl and riscv implementation of those prctls. Split them again.
- set_shstk_status/set_indir_lp_status perform CSR writes only when CPU
support is available. As suggested by Zong Li.
- Some minor clean up in kselftests as suggested by Zong Li.
v11:
- patch "arch/riscv: compile vdso with landing pad" was unconditionally
selecting `_zicfilp` for vDSO compile. fixed that. Changed `lpad 1` to
to `lpad 0`.
v10:
- dropped "mm: helper `is_shadow_stack_vma` to check shadow stack vma". This patch
is not that interesting to this patch series for risc-v. There are instances in
arch directories where VM_SHADOW_STACK flag is anyways used. Dropping this patch
to expedite merging in riscv tree.
- Took suggestions from `Clement` on "riscv: zicfiss / zicfilp enumeration" to
validate presence of cfi based on config.
- Added a patch for vDSO to have `lpad 0`. I had omitted this earlier to make sure
we add single vdso object with cfi enabled. But a vdso object with scheme of
zero labeled landing pad is least common denominator and should work with all
objects of zero labeled as well as function-signature labeled objects.
v9:
- rebased on master (39a803b754d5 fix braino in "9p: fix ->rename_sem exclusion")
- dropped "mm: Introduce ARCH_HAS_USER_SHADOW_STACK" (master has it from arm64/gcs)
- dropped "prctl: arch-agnostic prctl for shadow stack" (master has it from arm64/gcs)
v8:
- rebased on palmer/for-next
- dropped samuel holland's `envcfg` context switch patches.
they are in parlmer/for-next
v7:
- Removed "riscv/Kconfig: enable HAVE_EXIT_THREAD for riscv"
Instead using `deactivate_mm` flow to clean up.
see here for more context
https://lore.kernel.org/all/20230908203655.543765-1-rick.p.edgecombe@intel.…
- Changed the header include in `kselftest`. Hopefully this fixes compile
issue faced by Zong Li at SiFive.
- Cleaned up an orphaned change to `mm/mmap.c` in below patch
"riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE"
- Lock interfaces for shadow stack and indirect branch tracking expect arg == 0
Any future evolution of this interface should accordingly define how arg should
be setup.
- `mm/map.c` has an instance of using `VM_SHADOW_STACK`. Fixed it to use helper
`is_shadow_stack_vma`.
- Link to v6: https://lore.kernel.org/r/20241008-v5_user_cfi_series-v6-0-60d9fe073f37@riv…
v6:
- Picked up Samuel Holland's changes as is with `envcfg` placed in
`thread` instead of `thread_info`
- fixed unaligned newline escapes in kselftest
- cleaned up messages in kselftest and included test output in commit message
- fixed a bug in clone path reported by Zong Li
- fixed a build issue if CONFIG_RISCV_ISA_V is not selected
(this was introduced due to re-factoring signal context
management code)
v5:
- rebased on v6.12-rc1
- Fixed schema related issues in device tree file
- Fixed some of the documentation related issues in zicfilp/ss.rst
(style issues and added index)
- added `SHADOW_STACK_SET_MARKER` so that implementation can define base
of shadow stack.
- Fixed warnings on definitions added in usercfi.h when
CONFIG_RISCV_USER_CFI is not selected.
- Adopted context header based signal handling as proposed by Andy Chiu
- Added support for enabling kernel mode access to shadow stack using
FWFT
(https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-firmware…)
- Link to v5: https://lore.kernel.org/r/20241001-v5_user_cfi_series-v1-0-3ba65b6e550f@riv…
(Note: I had an issue in my workflow due to which version number wasn't
picked up correctly while sending out patches)
v4:
- rebased on 6.11-rc6
- envcfg: Converged with Samuel Holland's patches for envcfg management on per-
thread basis.
- vma_is_shadow_stack is renamed to is_vma_shadow_stack
- picked up Mark Brown's `ARCH_HAS_USER_SHADOW_STACK` patch
- signal context: using extended context management to maintain compatibility.
- fixed `-Wmissing-prototypes` compiler warnings for prctl functions
- Documentation fixes and amending typos.
- Link to v4: https://lore.kernel.org/all/20240912231650.3740732-1-debug@rivosinc.com/
v3:
- envcfg
logic to pick up base envcfg had a bug where `ENVCFG_CBZE` could have been
picked on per task basis, even though CPU didn't implement it. Fixed in
this series.
- dt-bindings
As suggested, split into separate commit. fixed the messaging that spec is
in public review
- arch_is_shadow_stack change
arch_is_shadow_stack changed to vma_is_shadow_stack
- hwprobe
zicfiss / zicfilp if present will get enumerated in hwprobe
- selftests
As suggested, added object and binary filenames to .gitignore
Selftest binary anyways need to be compiled with cfi enabled compiler which
will make sure that landing pad and shadow stack are enabled. Thus removed
separate enable/disable tests. Cleaned up tests a bit.
- Link to v3: https://lore.kernel.org/lkml/20240403234054.2020347-1-debug@rivosinc.com/
v2:
- Using config `CONFIG_RISCV_USER_CFI`, kernel support for riscv control flow
integrity for user mode programs can be compiled in the kernel.
- Enabling of control flow integrity for user programs is left to user runtime
- This patch series introduces arch agnostic `prctls` to enable shadow stack
and indirect branch tracking. And implements them on riscv.
---
Changes in v14:
- changelog posted just below cover letter
- Link to v13: https://lore.kernel.org/r/20250424-v5_user_cfi_series-v13-0-971437de586a@ri…
Changes in v13:
- changelog posted just below cover letter
- Link to v12: https://lore.kernel.org/r/20250314-v5_user_cfi_series-v12-0-e51202b53138@ri…
Changes in v12:
- changelog posted just below cover letter
- Link to v11: https://lore.kernel.org/r/20250310-v5_user_cfi_series-v11-0-86b36cbfb910@ri…
Changes in v11:
- changelog posted just below cover letter
- Link to v10: https://lore.kernel.org/r/20250210-v5_user_cfi_series-v10-0-163dcfa31c60@ri…
---
Andy Chiu (1):
riscv: signal: abstract header saving for setup_sigcontext
Deepak Gupta (25):
mm: VM_SHADOW_STACK definition for riscv
dt-bindings: riscv: zicfilp and zicfiss in dt-bindings (extensions.yaml)
riscv: zicfiss / zicfilp enumeration
riscv: zicfiss / zicfilp extension csr and bit definitions
riscv: usercfi state for task and save/restore of CSR_SSP on trap entry/exit
riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE
riscv mm: manufacture shadow stack pte
riscv mmu: teach pte_mkwrite to manufacture shadow stack PTEs
riscv mmu: write protect and shadow stack
riscv/mm: Implement map_shadow_stack() syscall
riscv/shstk: If needed allocate a new shadow stack on clone
riscv: Implements arch agnostic shadow stack prctls
prctl: arch-agnostic prctl for indirect branch tracking
riscv: Implements arch agnostic indirect branch tracking prctls
riscv/traps: Introduce software check exception
riscv/signal: save and restore of shadow stack for signal
riscv/kernel: update __show_regs to print shadow stack register
riscv/ptrace: riscv cfi status and state via ptrace and in core files
riscv/hwprobe: zicfilp / zicfiss enumeration in hwprobe
riscv: kernel command line option to opt out of user cfi
riscv: enable kernel access to shadow stack memory via FWFT sbi call
riscv: create a config for shadow stack and landing pad instr support
riscv: Documentation for landing pad / indirect branch tracking
riscv: Documentation for shadow stack on riscv
kselftest/riscv: kselftest for user mode cfi
Jim Shu (1):
arch/riscv: compile vdso with landing pad
Documentation/admin-guide/kernel-parameters.txt | 8 +
Documentation/arch/riscv/index.rst | 2 +
Documentation/arch/riscv/zicfilp.rst | 115 +++++
Documentation/arch/riscv/zicfiss.rst | 179 +++++++
.../devicetree/bindings/riscv/extensions.yaml | 14 +
arch/riscv/Kconfig | 20 +
arch/riscv/Makefile | 5 +-
arch/riscv/include/asm/asm-prototypes.h | 1 +
arch/riscv/include/asm/assembler.h | 44 ++
arch/riscv/include/asm/cpufeature.h | 12 +
arch/riscv/include/asm/csr.h | 16 +
arch/riscv/include/asm/entry-common.h | 2 +
arch/riscv/include/asm/hwcap.h | 2 +
arch/riscv/include/asm/mman.h | 25 +
arch/riscv/include/asm/mmu_context.h | 7 +
arch/riscv/include/asm/pgtable.h | 30 +-
arch/riscv/include/asm/processor.h | 2 +
arch/riscv/include/asm/thread_info.h | 3 +
arch/riscv/include/asm/usercfi.h | 95 ++++
arch/riscv/include/asm/vector.h | 3 +
arch/riscv/include/uapi/asm/hwprobe.h | 2 +
arch/riscv/include/uapi/asm/ptrace.h | 34 ++
arch/riscv/include/uapi/asm/sigcontext.h | 1 +
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/asm-offsets.c | 8 +
arch/riscv/kernel/cpufeature.c | 13 +
arch/riscv/kernel/entry.S | 33 +-
arch/riscv/kernel/head.S | 23 +
arch/riscv/kernel/process.c | 26 +-
arch/riscv/kernel/ptrace.c | 95 ++++
arch/riscv/kernel/signal.c | 148 +++++-
arch/riscv/kernel/sys_hwprobe.c | 2 +
arch/riscv/kernel/sys_riscv.c | 10 +
arch/riscv/kernel/traps.c | 43 ++
arch/riscv/kernel/usercfi.c | 545 +++++++++++++++++++++
arch/riscv/kernel/vdso/Makefile | 6 +
arch/riscv/kernel/vdso/flush_icache.S | 4 +
arch/riscv/kernel/vdso/getcpu.S | 4 +
arch/riscv/kernel/vdso/rt_sigreturn.S | 4 +
arch/riscv/kernel/vdso/sys_hwprobe.S | 4 +
arch/riscv/mm/init.c | 2 +-
arch/riscv/mm/pgtable.c | 17 +
include/linux/cpu.h | 4 +
include/linux/mm.h | 7 +
include/uapi/linux/elf.h | 2 +
include/uapi/linux/prctl.h | 27 +
kernel/sys.c | 30 ++
tools/testing/selftests/riscv/Makefile | 2 +-
tools/testing/selftests/riscv/cfi/.gitignore | 3 +
tools/testing/selftests/riscv/cfi/Makefile | 10 +
tools/testing/selftests/riscv/cfi/cfi_rv_test.h | 82 ++++
tools/testing/selftests/riscv/cfi/riscv_cfi_test.c | 171 +++++++
tools/testing/selftests/riscv/cfi/shadowstack.c | 385 +++++++++++++++
tools/testing/selftests/riscv/cfi/shadowstack.h | 27 +
54 files changed, 2331 insertions(+), 29 deletions(-)
---
base-commit: 4181f8ad7a1061efed0219951d608d4988302af7
change-id: 20240930-v5_user_cfi_series-3dc332f8f5b2
--
- debug
From: Ihor Solodrai <ihor.solodrai(a)linux.dev>
[ Upstream commit f2858f308131a09e33afb766cd70119b5b900569 ]
"sockmap_ktls disconnect_after_delete" test has been failing on BPF CI
after recent merges from netdev:
* https://github.com/kernel-patches/bpf/actions/runs/14458537639
* https://github.com/kernel-patches/bpf/actions/runs/14457178732
It happens because disconnect has been disabled for TLS [1], and it
renders the test case invalid.
Removing all the test code creates a conflict between bpf and
bpf-next, so for now only remove the offending assert [2].
The test will be removed later on bpf-next.
[1] https://lore.kernel.org/netdev/20250404180334.3224206-1-kuba@kernel.org/
[2] https://lore.kernel.org/bpf/cfc371285323e1a3f3b006bfcf74e6cf7ad65258@linux.…
Signed-off-by: Ihor Solodrai <ihor.solodrai(a)linux.dev>
Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen(a)linux.dev>
Link: https://lore.kernel.org/bpf/20250416170246.2438524-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
index 2d0796314862a..0a99fd404f6dc 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
@@ -68,7 +68,6 @@ static void test_sockmap_ktls_disconnect_after_delete(int family, int map)
goto close_cli;
err = disconnect(cli);
- ASSERT_OK(err, "disconnect");
close_cli:
close(cli);
--
2.39.5
Abstract
===
This patchset improves the performance of sockmap by providing CPU affinity,
resulting in a 1-10x increase in throughput.
Motivation
===
Traditional user-space reverse proxy:
Reserve Proxy
_________________
client -> | fd1 <-> fd2 | -> server
|_________________|
Using sockmap for reverse proxy:
Reserve Proxy
_________________
client -> | fd1 <-> fd2 | -> server
| |_________________| |
| | | |
| _________ |
| | sockmap | |
--> |_________| -->
By adding fds to sockmap and using a BPF program, we can quickly forward
data and avoid data copying between user space and kernel space.
Mainstream multi-process reverse proxy applications, such as Nginx and
HAProxy, support CPU affinity settings, which allow each process to be
pinned to a specific CPU, avoiding conflicts between data plane processes
and other processes, especially in multi-tenant environments.
Current Issues
===
The current design of sockmap uses a workqueue to forward ingress_skb and
wakes up the workqueue without specifying a CPU
(by calling schedule_delayed_work()). In the current implementation of
schedule_delayed_work, it tends to run the workqueue on the current CPU.
This approach has a high probability of running on the current CPU, which
is the same CPU that handles the net rx soft interrupt, especially for
programs that access each other using local interfaces.
The loopback driver's transmit interface, loopback_xmit(), directly calls
__netif_rx() on the current CPU, which means that the CPU handling
sockmap's workqueue and the client's sending CPU are the same, resulting
in contention.
For a TCP flow, if the request or response is very large, the
psock->ingress_skb queue can become very long. When the workqueue
traverses this queue to forward the data, it can consume a significant
amount of CPU time.
Solution
===
Configuring RPS on a loopback interface can be useful, but it will trigger
additional softirq, and furthermore, it fails to achieve our expected
effect of CPU isolation from other processes.
Instead, we provide a kfunc that allow users to specify the CPU on which
the workqueue runs through a BPF program.
We can use the existing benchmark to test the performance, which allows
us to evaluate the effectiveness of this optimization.
Because we use local interfaces for communication and the client consumes
a significant amount of CPU when sending data, this prevents the workqueue
from processing ingress_skb in a timely manner, ultimately causing the
server to fail to read data quickly.
Without cpu-affinity:
./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --no-verify
Setting up benchmark 'sockmap'...
create socket fd c1:14 p1:15 c2:16 p2:17
Benchmark 'sockmap' started.
Iter 0 ( 36.031us): Send Speed 1143.693 MB/s ... Rcv Speed 109.572 MB/s
Iter 1 ( 0.608us): Send Speed 1320.550 MB/s ... Rcv Speed 48.103 MB/s
Iter 2 ( -5.448us): Send Speed 1314.790 MB/s ... Rcv Speed 47.842 MB/s
Iter 3 ( -0.613us): Send Speed 1320.158 MB/s ... Rcv Speed 46.531 MB/s
Iter 4 ( -3.441us): Send Speed 1319.375 MB/s ... Rcv Speed 46.662 MB/s
Iter 5 ( 3.764us): Send Speed 1166.667 MB/s ... Rcv Speed 42.467 MB/s
Iter 6 ( -4.404us): Send Speed 1319.508 MB/s ... Rcv Speed 47.973 MB/s
Summary: total trans 7758 MB ± 1293.506 MB/s
Without cpu-affinity(RPS enabled):
./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --no-verify
Setting up benchmark 'sockmap'...
create socket fd c1:14 p1:15 c2:16 p2:17
Benchmark 'sockmap' started.
Iter 0 ( 28.925us): Send Speed 1630.357 MB/s ... Rcv Speed 850.960 MB/s
Iter 1 ( -2.042us): Send Speed 1644.564 MB/s ... Rcv Speed 822.478 MB/s
Iter 2 ( 0.754us): Send Speed 1644.297 MB/s ... Rcv Speed 850.787 MB/s
Iter 3 ( 0.159us): Send Speed 1644.429 MB/s ... Rcv Speed 850.198 MB/s
Iter 4 ( -2.898us): Send Speed 1646.924 MB/s ... Rcv Speed 830.867 MB/s
Iter 5 ( -0.210us): Send Speed 1649.410 MB/s ... Rcv Speed 824.246 MB/s
Iter 6 ( -1.448us): Send Speed 1650.723 MB/s ... Rcv Speed 808.256 MB/s
With cpu-affinity(RPS disabled):
./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --no-verify --cpu-affinity
Setting up benchmark 'sockmap'...
create socket fd c1:14 p1:15 c2:16 p2:17
Benchmark 'sockmap' started.
Iter 0 ( 36.051us): Send Speed 1883.437 MB/s ... Rcv Speed 1865.087 MB/s
Iter 1 ( 1.246us): Send Speed 1900.542 MB/s ... Rcv Speed 1761.737 MB/s
Iter 2 ( -8.595us): Send Speed 1883.128 MB/s ... Rcv Speed 1860.714 MB/s
Iter 3 ( 7.033us): Send Speed 1890.831 MB/s ... Rcv Speed 1806.684 MB/s
Iter 4 ( -8.397us): Send Speed 1884.700 MB/s ... Rcv Speed 1973.568 MB/s
Iter 5 ( -1.822us): Send Speed 1894.125 MB/s ... Rcv Speed 1775.046 MB/s
Iter 6 ( 4.936us): Send Speed 1877.597 MB/s ... Rcv Speed 1959.320 MB/s
Summary: total trans 11328 MB ± 1888.507 MB/s
Appendix
===
Through this optimization, we discovered that sk_mem_charge()
and sk_mem_uncharge() have concurrency issues. The performance improvement
brought by this optimization has made these concurrency issues more
evident.
This concurrency issue can cause the WARN_ON_ONCE(sk->sk_forward_alloc)
check to be triggered when the socket is released. Since this patch is a
feature-type patch and does not intend to fix this bug, I will provide
additional patches to fix this issue later.
Jiayuan Chen (3):
bpf, sockmap: Introduce a new kfunc for sockmap
bpf, sockmap: Affinitize workqueue to a specific CPU
selftest/bpf/benchs: Add cpu-affinity for sockmap bench
Documentation/bpf/map_sockmap.rst | 14 +++++++
include/linux/skmsg.h | 15 +++++++
kernel/bpf/btf.c | 3 ++
net/core/skmsg.c | 10 +++--
net/core/sock_map.c | 39 +++++++++++++++++++
.../selftests/bpf/benchs/bench_sockmap.c | 35 +++++++++++++++--
tools/testing/selftests/bpf/bpf_kfuncs.h | 6 +++
.../selftests/bpf/progs/bench_sockmap_prog.c | 7 ++++
8 files changed, 122 insertions(+), 7 deletions(-)
--
2.47.1
From: Ihor Solodrai <ihor.solodrai(a)linux.dev>
[ Upstream commit f2858f308131a09e33afb766cd70119b5b900569 ]
"sockmap_ktls disconnect_after_delete" test has been failing on BPF CI
after recent merges from netdev:
* https://github.com/kernel-patches/bpf/actions/runs/14458537639
* https://github.com/kernel-patches/bpf/actions/runs/14457178732
It happens because disconnect has been disabled for TLS [1], and it
renders the test case invalid.
Removing all the test code creates a conflict between bpf and
bpf-next, so for now only remove the offending assert [2].
The test will be removed later on bpf-next.
[1] https://lore.kernel.org/netdev/20250404180334.3224206-1-kuba@kernel.org/
[2] https://lore.kernel.org/bpf/cfc371285323e1a3f3b006bfcf74e6cf7ad65258@linux.…
Signed-off-by: Ihor Solodrai <ihor.solodrai(a)linux.dev>
Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen(a)linux.dev>
Link: https://lore.kernel.org/bpf/20250416170246.2438524-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
index 2d0796314862a..0a99fd404f6dc 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
@@ -68,7 +68,6 @@ static void test_sockmap_ktls_disconnect_after_delete(int family, int map)
goto close_cli;
err = disconnect(cli);
- ASSERT_OK(err, "disconnect");
close_cli:
close(cli);
--
2.39.5
From: Ihor Solodrai <ihor.solodrai(a)linux.dev>
[ Upstream commit f2858f308131a09e33afb766cd70119b5b900569 ]
"sockmap_ktls disconnect_after_delete" test has been failing on BPF CI
after recent merges from netdev:
* https://github.com/kernel-patches/bpf/actions/runs/14458537639
* https://github.com/kernel-patches/bpf/actions/runs/14457178732
It happens because disconnect has been disabled for TLS [1], and it
renders the test case invalid.
Removing all the test code creates a conflict between bpf and
bpf-next, so for now only remove the offending assert [2].
The test will be removed later on bpf-next.
[1] https://lore.kernel.org/netdev/20250404180334.3224206-1-kuba@kernel.org/
[2] https://lore.kernel.org/bpf/cfc371285323e1a3f3b006bfcf74e6cf7ad65258@linux.…
Signed-off-by: Ihor Solodrai <ihor.solodrai(a)linux.dev>
Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen(a)linux.dev>
Link: https://lore.kernel.org/bpf/20250416170246.2438524-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
index 2d0796314862a..0a99fd404f6dc 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
@@ -68,7 +68,6 @@ static void test_sockmap_ktls_disconnect_after_delete(int family, int map)
goto close_cli;
err = disconnect(cli);
- ASSERT_OK(err, "disconnect");
close_cli:
close(cli);
--
2.39.5
From: Ihor Solodrai <ihor.solodrai(a)linux.dev>
[ Upstream commit f2858f308131a09e33afb766cd70119b5b900569 ]
"sockmap_ktls disconnect_after_delete" test has been failing on BPF CI
after recent merges from netdev:
* https://github.com/kernel-patches/bpf/actions/runs/14458537639
* https://github.com/kernel-patches/bpf/actions/runs/14457178732
It happens because disconnect has been disabled for TLS [1], and it
renders the test case invalid.
Removing all the test code creates a conflict between bpf and
bpf-next, so for now only remove the offending assert [2].
The test will be removed later on bpf-next.
[1] https://lore.kernel.org/netdev/20250404180334.3224206-1-kuba@kernel.org/
[2] https://lore.kernel.org/bpf/cfc371285323e1a3f3b006bfcf74e6cf7ad65258@linux.…
Signed-off-by: Ihor Solodrai <ihor.solodrai(a)linux.dev>
Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen(a)linux.dev>
Link: https://lore.kernel.org/bpf/20250416170246.2438524-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
index 2d0796314862a..0a99fd404f6dc 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_ktls.c
@@ -68,7 +68,6 @@ static void test_sockmap_ktls_disconnect_after_delete(int family, int map)
goto close_cli;
err = disconnect(cli);
- ASSERT_OK(err, "disconnect");
close_cli:
close(cli);
--
2.39.5