From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com>
Hello,
Please find the v12 AccECN protocol patch series, which covers the core
functionality of Accurate ECN, AccECN negotiation, AccECN TCP options,
and AccECN failure handling. The Accurate ECN draft can be found in
https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-accurate-ecn-28
This patch series is part of the full AccECN patch series, which is available at
https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/
Best Regards,
Chia-Yu
---
v12 (04-Jul-2025)
- Fix compilation issues with some intermediate patches in v11
- Add more comments for AccECN helpers of tcp_ecn.h
v11 (03-Jul-2025)
- Fix compilation issues with some intermediate patches in v10
v10 (02-Jul-2025)
- Add new patch of separated header file include/net/tcp_ecn.h to include ECN and AccECN functions (Eric Dumazet <edumazet(a)google.com>)
- Add comments on the AccECN helper functions in tcp_ecn.h (Eric Dumazet <edumazet(a)google.com>)
- Add documentation of tcp_ecn, tcp_ecn_option, tcp_ecn_beacon in ip-sysctl.rst to the corresponding patch (Eric Dumazet <edumazet(a)google.com>)
- Split wait third ACK functionality into a separated patch from AccECN negotiation patch (Eric Dumazet <edumazet(a)google.com>)
- Add READ_ONCE() over every reads of sysctl for all patches in the series (Eric Dumazet <edumazet(a)google.com>)
- Merge heuristics of AccECN option ceb/cep and ACE field multi-wrap into a single patch
- Add a table of SACK block reduction and required AccECN field in patch #15 commit message (Eric Dumazet <edumazet(a)google.com>)
v9 (21-Jun-2025)
- Use tcp_data_ecn_check() to set TCP_ECN_SEE flag only for RFC3168 ECN (Paolo Abeni <pabeni(a)redhat.com>)
- Add comments about setting TCP_ECN_SEEN flag for RFC3168 and Accruate ECN (Paolo Abeni <pabeni(a)redhat.com>)
- Restruct the code in the for loop of tcp_accecn_process_option() (Paolo Abeni <pabeni(a)redhat.com>)
- Remove ecn_bytes and add use_synack_ecn_bytes flag to identify whether syn_ack_bytes or received_ecn_bytes is used (Paolo Abeni <pabeni(a)redhat.com>)
- Replace leftover_bytes and leftover_size with leftover_highbyte and leftover_lowbyte and add comments in tcp_options_write() (Paolo Abeni <pabeni(a)redhat.com>)
- Add comments and commit message about the 1st retx SYN still attempt AccECN negotiation (Paolo Abeni <pabeni(a)redhat.com>)
v8 (10-Jun-2025)
- Add new helper function tcp_ecn_received_counters_payload() in #6 (Paolo Abeni <pabeni(a)redhat.com>)
- Set opts->num_sack_blocks=0 to avoid potential undefined value in #8 (Paolo Abeni <pabeni(a)redhat.com>)
- Reset leftover_size to 2 once leftover_bytes is used in #9 (Paolo Abeni <pabeni(a)redhat.com>)
- Add new helper function tcp_accecn_opt_demand_min() in #10 (Paolo Abeni <pabeni(a)redhat.com>)
- Add new helper function tcp_accecn_saw_opt_fail_recv() in #11 (Paolo Abeni <pabeni(a)redhat.com>)
- Update tcp_options_fit_accecn() to avoid using recursion in #14 (Paolo Abeni <pabeni(a)redhat.com>)
v7 (14-May-2025)
- Modify group sizes of tcp_sock_write_txrx and tcp_sock_write_rx in #3 based on pahole results (Paolo Abeni <pabeni(a)redhat.com>)
- Fix the issue in #4 and #5 where the RFC3168 ECN behavior in tcp_ecn_send() is changed (Paolo Abeni <pabeni(a)redhat.com>)
- Modify group size of tcp_sock_write_txrx in #4 and #6 based on pahole results (Paolo Abeni <pabeni(a)redhat.com>)
- Update commit message for #9 to explain the increase in tcp_sock_write_rx group size
- Modify group size of tcp_sock_write_tx in #10 based on pahole results
v6 (09-May-2025)
- Add #3 to utilize exisintg holes of tcp_sock_write_txrx group for later patches (#4, #9, #10) with new u8 members (Paolo Abeni <pabeni(a)redhat.com>)
- Add pahole outcomes before and after commit in #4, #5, #6, #9, #10, #15 (Paolo Abeni <pabeni(a)redhat.com>)
- Define new helper function tcp_send_ack_reflect_ect() for sending ACK with reflected ECT in #5 (Paolo Abeni <pabeni(a)redhat.com>)
- Add comments for function tcp_ecn_rcv_synack() in #5 (Paolo Abeni <pabeni(a)redhat.com>)
- Add enum/define to be used by sysctl_tcp_ecn in #5, sysctl_tcp_ecn_option in #9, and sysctl_tcp_ecn_option_beacon in #10 (Paolo Abeni <pabeni(a)redhat.com>)
- Move accecn_fail_mode and saw_accecn_opt in #5 and #11 to use exisintg holes of tcp_sock (Paolo Abeni <pabeni(a)redhat.com>)
- Change data type of new members of tcp_request_sock and move them to the end of struct in #5 and #11 (Paolo Abeni <pabeni(a)redhat.com>)
- Move new members of tcp_info to the end of struct in #6 (Paolo Abeni <pabeni(a)redhat.com>)
- Merge previous #7 into #9 (Paolo Abeni <pabeni(a)redhat.com>)
- Mask ecnfield with INET_ECN_MASK to remove WARN_ONCE in #9 (Paolo Abeni <pabeni(a)redhat.com>)
- Reduce the indentation levels for reabability in #9 and #10 (Paolo Abeni <pabeni(a)redhat.com>)
- Move delivered_ecn_bytes to the RX group in #9, accecn_opt_tstamp to the TX group in #10, pkts_acked_ewma to the RX group in #15 (Paolo Abeni <pabeni(a)redhat.com>)
- Add changes in Documentation/networking/net_cachelines/tcp_sock.rst for new tcp_sock members in #3, #5, #6, #9, #10, #15
v5 (22-Apr-2025)
- Further fix for 32-bit ARM alignment in tcp.c (Simon Horman <horms(a)kernel.org>)
v4 (18-Apr-2025)
- Fix 32-bit ARM assertion for alignment requirement (Simon Horman <horms(a)kernel.org>)
v3 (14-Apr-2025)
- Fix patch apply issue in v2 (Jakub Kicinski <kuba(a)kernel.org>)
v2 (18-Mar-2025)
- Add one missing patch from the previous AccECN protocol preparation patch series to this patch series.
---
Chia-Yu Chang (6):
tcp: reorganize tcp_sock_write_txrx group for variables later
tcp: ecn functions in separated include file
tcp: Add wait_third_ack for ECN negotiation in simultaneous connect
tcp: accecn: AccECN option send control
tcp: accecn: AccECN option failure handling
tcp: accecn: try to fit AccECN option with SACK
Ilpo Järvinen (9):
tcp: reorganize SYN ECN code
tcp: fast path functions later
tcp: AccECN core
tcp: accecn: AccECN negotiation
tcp: accecn: add AccECN rx byte counters
tcp: accecn: AccECN needs to know delivered bytes
tcp: sack option handling improvements
tcp: accecn: AccECN option
tcp: accecn: AccECN option ceb/cep and ACE field multi-wrap heuristics
Documentation/networking/ip-sysctl.rst | 55 +-
.../networking/net_cachelines/tcp_sock.rst | 13 +
include/linux/tcp.h | 33 +-
include/net/netns/ipv4.h | 2 +
include/net/tcp.h | 87 ++-
include/net/tcp_ecn.h | 663 ++++++++++++++++++
include/uapi/linux/tcp.h | 7 +
net/ipv4/syncookies.c | 4 +
net/ipv4/sysctl_net_ipv4.c | 19 +
net/ipv4/tcp.c | 29 +-
net/ipv4/tcp_input.c | 371 ++++++++--
net/ipv4/tcp_ipv4.c | 8 +-
net/ipv4/tcp_minisocks.c | 40 +-
net/ipv4/tcp_output.c | 297 ++++++--
net/ipv6/syncookies.c | 2 +
net/ipv6/tcp_ipv6.c | 1 +
16 files changed, 1444 insertions(+), 187 deletions(-)
create mode 100644 include/net/tcp_ecn.h
--
2.34.1
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
---------
v17:
- fixed warnings due to empty macros in usercfi.h (reported by alexg)
- fixed prefixes in commit titles reported by alexg
- took below uprobe with fcfi v2 patch from Zong Li and squashed it with
"riscv/traps: Introduce software check exception and uprobe handling"
https://lore.kernel.org/all/20250604093403.10916-1-zong.li@sifive.com/
v16:
- If FWFT is not implemented or returns error for shadow stack activation, then
no_usercfi is set to disable shadow stack. Although this should be picked up
by extension validation and activation. Fixed this bug for zicfilp and zicfiss
both. Thanks to Charlie Jenkins for reporting this.
- If toolchain doesn't support cfi, cfi kselftest shouldn't build. Suggested by
Charlie Jenkins.
- Default for CONFIG_RISCV_USER_CFI is set to no. Charlie/Atish suggested to
keep it off till we have more hardware availibility with RVA23 profile and
zimop/zcmop implemented. Else this will start breaking people's workflow
- Includes the fix if "!RV64 and !SBI" then definitions for FWFT in
asm-offsets.c error.
v15:
- Toolchain has been updated to include `-fcf-protection` flag. This
exists for x86 as well. Updated kernel patches to compile vDSO and
selftest to compile with `fcf-protection=full` flag.
- selecting CONFIG_RISCV_USERCFI selects CONFIG_RISCV_SBI.
- Patch to enable shadow stack for kernel wasn't hidden behind
CONFIG_RISCV_USERCFI and CONFIG_RISCV_SBI. fixed that.
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 v17:
- Link to v16: https://lore.kernel.org/r/20250522-v5_user_cfi_series-v16-0-64f61a35eee7@ri…
Changes in v16:
- Link to v15: https://lore.kernel.org/r/20250502-v5_user_cfi_series-v15-0-914966471885@ri…
Changes in v15:
- changelog posted just below cover letter
- Link to v14: https://lore.kernel.org/r/20250429-v5_user_cfi_series-v14-0-5239410d012a@ri…
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/mm: teach pte_mkwrite to manufacture shadow stack PTEs
riscv/mm: 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 and uprobe handling
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 | 21 +
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 | 26 +
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 | 10 +
arch/riscv/kernel/cpufeature.c | 27 +
arch/riscv/kernel/entry.S | 33 +-
arch/riscv/kernel/head.S | 27 +
arch/riscv/kernel/process.c | 27 +-
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 | 51 ++
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 | 16 +
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 | 16 +
tools/testing/selftests/riscv/cfi/cfi_rv_test.h | 82 ++++
tools/testing/selftests/riscv/cfi/riscv_cfi_test.c | 173 +++++++
tools/testing/selftests/riscv/cfi/shadowstack.c | 385 +++++++++++++++
tools/testing/selftests/riscv/cfi/shadowstack.h | 27 +
54 files changed, 2369 insertions(+), 29 deletions(-)
---
base-commit: 4181f8ad7a1061efed0219951d608d4988302af7
change-id: 20240930-v5_user_cfi_series-3dc332f8f5b2
--
- debug
This patch series add tests to validate XDP native support for PASS,
DROP, ABORT, and TX actions, as well as headroom and tailroom adjustment.
For adjustment tests, validate support for both the extension and
shrinking cases across various packet sizes and offset values.
The pass criteria for head/tail adjustment tests require that at-least
one adjustment value works for at-least one packet size. This ensure
that the variability in maximum supported head/tail adjustment offset
across different drivers is being incorporated.
The results reported in this series are based on fbnic. However, the
series is tested against multiple other drivers including netdevism.
Note: The XDP support for fbnic will be added later.
---
Change-log:
V4:
- Support XDP handling for netdevsim
- Fix pylint warning with P4
- Update commit message for P2,P3 to show pass/fail summary
V3: https://lore.kernel.org/netdev/20250712002648.2385849-1-mohsin.bashr@gmail.…
V2: https://lore.kernel.org/netdev/20250710184351.63797-1-mohsin.bashr@gmail.com
V1: https://lore.kernel.org/netdev/20250709173707.3177206-1-mohsin.bashr@gmail.…
Jakub Kicinski (1):
net: netdevsim: hook in XDP handling
Mohsin Bashir (4):
selftests: drv-net: Test XDP_PASS/DROP support
selftests: drv-net: Test XDP_TX support
selftests: drv-net: Test tail-adjustment support
selftests: drv-net: Test head-adjustment support
drivers/net/netdevsim/netdev.c | 19 +-
tools/testing/selftests/drivers/net/Makefile | 1 +
tools/testing/selftests/drivers/net/xdp.py | 656 ++++++++++++++++++
.../selftests/net/lib/xdp_native.bpf.c | 538 ++++++++++++++
4 files changed, 1213 insertions(+), 1 deletion(-)
create mode 100755 tools/testing/selftests/drivers/net/xdp.py
create mode 100644 tools/testing/selftests/net/lib/xdp_native.bpf.c
--
2.47.1
Hi everyone,
Here's a V3 for the netdevsim PHY support. This V3 includes :
- A fix for a compiling issue with PHYLIB=n
- An updated KConfig to only allow PHYLIB=y|n
- Converted the link setting file to a bool debugfs file, relying on
link state polling
The idea of this series is to allow attaching virtual PHY devices to
netdevsim, so that we can test PHY-related ethtool commands. This can be
extended in the future for phylib testing as well.
V2: https://lore.kernel.org/netdev/20250708115531.111326-1-maxime.chevallier@bo…
- Fix building with PHYLIB=m
- Use shellcheck on the shell scripts
V1: https://lore.kernel.org/netdev/20250702082806.706973-1-maxime.chevallier@bo…
Maxime Chevallier (3):
net: netdevsim: Add PHY support in netdevsim
selftests: ethtool: Drop the unused old_netdevs variable
selftests: ethtool: Introduce ethernet PHY selftests on netdevsim
drivers/net/Kconfig | 1 +
drivers/net/netdevsim/Makefile | 4 +
drivers/net/netdevsim/dev.c | 2 +
drivers/net/netdevsim/netdev.c | 8 +
drivers/net/netdevsim/netdevsim.h | 25 ++
drivers/net/netdevsim/phy.c | 375 ++++++++++++++++++
.../selftests/drivers/net/netdevsim/config | 1 +
.../drivers/net/netdevsim/ethtool-common.sh | 19 +-
.../drivers/net/netdevsim/ethtool-phy.sh | 64 +++
9 files changed, 496 insertions(+), 3 deletions(-)
create mode 100644 drivers/net/netdevsim/phy.c
create mode 100755 tools/testing/selftests/drivers/net/netdevsim/ethtool-phy.sh
--
2.49.0
There is a spelling mistake in a ksft_exit_fail_msg message. Fix it.
Signed-off-by: Colin Ian King <colin.i.king(a)gmail.com>
---
tools/testing/selftests/futex/functional/futex_priv_hash.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/futex/functional/futex_priv_hash.c b/tools/testing/selftests/futex/functional/futex_priv_hash.c
index a9cedc365102..aea001ac4946 100644
--- a/tools/testing/selftests/futex/functional/futex_priv_hash.c
+++ b/tools/testing/selftests/futex/functional/futex_priv_hash.c
@@ -122,7 +122,7 @@ static void futex_dummy_op(void)
}
ret = pthread_mutex_timedlock(&lock, &timeout);
if (ret == 0)
- ksft_exit_fail_msg("Succeffuly locked an already locked mutex.\n");
+ ksft_exit_fail_msg("Successfully locked an already locked mutex.\n");
if (ret != ETIMEDOUT)
ksft_exit_fail_msg("pthread_mutex_timedlock() did not timeout: %d.\n", ret);
--
2.50.0
Move the generic `FORCE_READ` macro from `guard-regions.c` to the shared
`vm_util.h` header to promote code reuse.
In `guard-regions.c`, replace `ksft_exit_skip()` with the `SKIP()` macro
to ensure only the current test is skipped on permission failure, instead
of terminating the entire test binary.
Signed-off-by: wang lian <lianux.mm(a)gmail.com>
---
tools/testing/selftests/mm/guard-regions.c | 9 +--------
tools/testing/selftests/mm/vm_util.h | 7 +++++++
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/mm/guard-regions.c b/tools/testing/selftests/mm/guard-regions.c
index 93af3d3760f9..b0d42eb04e3a 100644
--- a/tools/testing/selftests/mm/guard-regions.c
+++ b/tools/testing/selftests/mm/guard-regions.c
@@ -35,13 +35,6 @@
static volatile sig_atomic_t signal_jump_set;
static sigjmp_buf signal_jmp_buf;
-/*
- * Ignore the checkpatch warning, we must read from x but don't want to do
- * anything with it in order to trigger a read page fault. We therefore must use
- * volatile to stop the compiler from optimising this away.
- */
-#define FORCE_READ(x) (*(volatile typeof(x) *)x)
-
/*
* How is the test backing the mapping being tested?
*/
@@ -582,7 +575,7 @@ TEST_F(guard_regions, process_madvise)
/* OK we don't have permission to do this, skip. */
if (count == -1 && errno == EPERM)
- ksft_exit_skip("No process_madvise() permissions, try running as root.\n");
+ SKIP(return, "No process_madvise() permissions, try running as root.\n");
/* Returns the number of bytes advised. */
ASSERT_EQ(count, 6 * page_size);
diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index 2b154c287591..c20298ae98ea 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -18,6 +18,13 @@
#define PM_SWAP BIT_ULL(62)
#define PM_PRESENT BIT_ULL(63)
+/*
+ * Ignore the checkpatch warning, we must read from x but don't want to do
+ * anything with it in order to trigger a read page fault. We therefore must use
+ * volatile to stop the compiler from optimising this away.
+ */
+#define FORCE_READ(x) (*(volatile typeof(x) *)x)
+
extern unsigned int __page_size;
extern unsigned int __page_shift;
--
2.43.0
mptcp_connect.sh can be executed manually with "-m <MODE>" and "-C" to
make sure everything works as expected when using "mmap" and "sendfile"
modes instead of "poll", and with the MPTCP checksum support.
These modes should be validated, but they are not when the selftests are
executed via the kselftest helpers. It means that most CIs validating
these selftests, like NIPA for the net development trees and LKFT for
the stable ones, are not covering these modes.
To fix that, new test programs have been added, simply calling
mptcp_connect.sh with the right parameters.
The first patch can be backported up to v5.6, and the second one up to
v5.14.
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
---
Matthieu Baerts (NGI0) (2):
selftests: mptcp: connect: also cover alt modes
selftests: mptcp: connect: also cover checksum
tools/testing/selftests/net/mptcp/Makefile | 3 ++-
tools/testing/selftests/net/mptcp/mptcp_connect_checksum.sh | 4 ++++
tools/testing/selftests/net/mptcp/mptcp_connect_mmap.sh | 4 ++++
tools/testing/selftests/net/mptcp/mptcp_connect_sendfile.sh | 4 ++++
4 files changed, 14 insertions(+), 1 deletion(-)
---
base-commit: b640daa2822a39ff76e70200cb2b7b892b896dce
change-id: 20250714-net-mptcp-sft-connect-alt-c1aaf073ef4e
Best regards,
--
Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
From: Yicong Yang <yangyicong(a)hisilicon.com>
Armv8.7 introduces single-copy atomic 64-byte loads and stores
instructions and its variants named under FEAT_{LS64, LS64_V}.
Add support for Armv8.7 FEAT_{LS64, LS64_V}:
- Add identifying and enabling in the cpufeature list
- Expose the support of these features to userspace through HWCAP3
and cpuinfo
- Add related hwcap test
- Handle the trap of unsupported memory (normal/uncacheable) access in a VM
A real scenario for this feature is that the userspace driver can make use of
this to implement direct WQE (workqueue entry) - a mechanism to fill WQE
directly into the hardware.
Picked Marc's 2 patches form [1] for handling the LS64 trap in a VM on emulated
MMIO and the introduce of KVM_EXIT_ARM_LDST64B.
[1] https://lore.kernel.org/linux-arm-kernel/20240815125959.2097734-1-maz@kerne…
Tested with updated hwcap test:
[root@localhost tmp]# dmesg | grep "All CPU(s) started"
[ 14.789859] CPU: All CPU(s) started at EL2
[root@localhost tmp]# ./hwcap
# LS64 present
ok 217 cpuinfo_match_LS64
ok 218 sigill_LS64
ok 219 # SKIP sigbus_LS64_V
# LS64_V present
ok 220 cpuinfo_match_LS64_V
ok 221 sigill_LS64_V
ok 222 # SKIP sigbus_LS64_V
# 115 skipped test(s) detected. Consider enabling relevant config options to improve coverage.
# Totals: pass:107 fail:0 xfail:0 xpass:0 skip:115 error:0
root@localhost:/mnt# dmesg | grep "All CPU(s) started"
[ 0.281152] CPU: All CPU(s) started at EL1
root@localhost:/mnt# ./hwcap
# LS64 present
ok 217 cpuinfo_match_LS64
ok 218 sigill_LS64
ok 219 # SKIP sigbus_LS64
# LS64_V present
ok 220 cpuinfo_match_LS64_V
ok 221 sigill_LS64_V
ok 222 # SKIP sigbus_LS64_V
# 115 skipped test(s) detected. Consider enabling relevant config options to improve coverage.
# Totals: pass:107 fail:0 xfail:0 xpass:0 skip:115 error:0
Change since v3:
- Inject DABT fault for LS64 fault on unsupported memory but with valid memslot
Link: https://lore.kernel.org/linux-arm-kernel/20250626080906.64230-1-yangyicong@…
Change since v2:
- Handle the LS64 fault to userspace and allow userspace to inject LS64 fault
- Reorder the patches to make KVM handling prior to feature support
Link: https://lore.kernel.org/linux-arm-kernel/20250331094320.35226-1-yangyicong@…
Change since v1:
- Drop the support for LS64_ACCDATA
- handle the DABT of unsupported memory type after checking the memory attributes
Link: https://lore.kernel.org/linux-arm-kernel/20241202135504.14252-1-yangyicong@…
Marc Zyngier (2):
KVM: arm64: Add exit to userspace on {LD,ST}64B* outside of memslots
KVM: arm64: Add documentation for KVM_EXIT_ARM_LDST64B
Yicong Yang (5):
KVM: arm64: Handle DABT caused by LS64* instructions on unsupported
memory
arm64: Provide basic EL2 setup for FEAT_{LS64, LS64_V} usage at EL0/1
arm64: Add support for FEAT_{LS64, LS64_V}
KVM: arm64: Enable FEAT_{LS64, LS64_V} in the supported guest
kselftest/arm64: Add HWCAP test for FEAT_{LS64, LS64_V}
Documentation/arch/arm64/booting.rst | 12 +++
Documentation/arch/arm64/elf_hwcaps.rst | 6 ++
Documentation/virt/kvm/api.rst | 43 +++++++++--
arch/arm64/include/asm/el2_setup.h | 12 ++-
arch/arm64/include/asm/esr.h | 8 ++
arch/arm64/include/asm/hwcap.h | 2 +
arch/arm64/include/asm/kvm_emulate.h | 7 ++
arch/arm64/include/uapi/asm/hwcap.h | 2 +
arch/arm64/kernel/cpufeature.c | 51 +++++++++++++
arch/arm64/kernel/cpuinfo.c | 2 +
arch/arm64/kvm/inject_fault.c | 29 ++++++++
arch/arm64/kvm/mmio.c | 27 ++++++-
arch/arm64/kvm/mmu.c | 14 +++-
arch/arm64/tools/cpucaps | 2 +
include/uapi/linux/kvm.h | 3 +-
tools/testing/selftests/arm64/abi/hwcap.c | 90 +++++++++++++++++++++++
16 files changed, 299 insertions(+), 11 deletions(-)
--
2.24.0