Re: [PATCH v23 00/28] riscv control-flow integrity for usermode

On Thu, 27 Nov 2025, patchwork-bot+linux-riscv@kernel.org wrote:

This series was applied to riscv/linux.git (for-next) by Paul Walmsley pjw@kernel.org:

[ the RISC-V CFI patch series ]

Here is the summary with links:

• [v23,01/28] mm: VM_SHADOW_STACK definition for riscv https://git.kernel.org/riscv/c/ae8460ac9db2
• [v23,02/28] dt-bindings: riscv: zicfilp and zicfiss in dt-bindings (extensions.yaml) https://git.kernel.org/riscv/c/b32ccfc268db
• [v23,03/28] riscv: zicfiss / zicfilp enumeration https://git.kernel.org/riscv/c/55a811a7f304
• [v23,04/28] riscv: zicfiss / zicfilp extension csr and bit definitions https://git.kernel.org/riscv/c/92c96b16548e
• [v23,05/28] riscv: usercfi state for task and save/restore of CSR_SSP on trap entry/exit https://git.kernel.org/riscv/c/7720cdd21962
• [v23,06/28] riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE https://git.kernel.org/riscv/c/e60eb198b13d
• [v23,07/28] riscv/mm: manufacture shadow stack pte https://git.kernel.org/riscv/c/f8fcb7b5bf30
• [v23,08/28] riscv/mm: teach pte_mkwrite to manufacture shadow stack PTEs https://git.kernel.org/riscv/c/0276a5ea1105
• [v23,09/28] riscv/mm: write protect and shadow stack https://git.kernel.org/riscv/c/ae615676bc37
• [v23,10/28] riscv/mm: Implement map_shadow_stack() syscall https://git.kernel.org/riscv/c/d291fd38f841
• [v23,11/28] riscv/shstk: If needed allocate a new shadow stack on clone https://git.kernel.org/riscv/c/d209ea2fa4bb
• [v23,12/28] riscv: Implements arch agnostic shadow stack prctls https://git.kernel.org/riscv/c/8b49f512abc2
• [v23,13/28] prctl: arch-agnostic prctl for indirect branch tracking https://git.kernel.org/riscv/c/3363a8d1044e
• [v23,14/28] riscv: Implements arch agnostic indirect branch tracking prctls https://git.kernel.org/riscv/c/0177891ccdb7
• [v23,15/28] riscv/traps: Introduce software check exception and uprobe handling https://git.kernel.org/riscv/c/6f71171a7448
• [v23,16/28] riscv: signal: abstract header saving for setup_sigcontext (no matching commit)
• [v23,17/28] riscv/signal: save and restore of shadow stack for signal https://git.kernel.org/riscv/c/4f9da7ad3478
• [v23,18/28] riscv/kernel: update __show_regs to print shadow stack register https://git.kernel.org/riscv/c/320c96a55d73
• [v23,19/28] riscv/ptrace: riscv cfi status and state via ptrace and in core files https://git.kernel.org/riscv/c/7a39f89a817e
• [v23,20/28] riscv/hwprobe: zicfilp / zicfiss enumeration in hwprobe https://git.kernel.org/riscv/c/c09b490a9267
• [v23,21/28] riscv: kernel command line option to opt out of user cfi https://git.kernel.org/riscv/c/6e0dc40ceb45
• [v23,22/28] riscv: enable kernel access to shadow stack memory via FWFT sbi call https://git.kernel.org/riscv/c/dfd087078357
• [v23,23/28] arch/riscv: compile vdso with landing pad and shadow stack note https://git.kernel.org/riscv/c/2cfe57e3bd9b
• [v23,24/28] arch/riscv: dual vdso creation logic and select vdso based on hw https://git.kernel.org/riscv/c/418316aa61e8
• [v23,25/28] riscv: create a config for shadow stack and landing pad instr support https://git.kernel.org/riscv/c/c5f5ce714457
• [v23,26/28] riscv: Documentation for landing pad / indirect branch tracking https://git.kernel.org/riscv/c/73d0ccec35b8
• [v23,27/28] riscv: Documentation for shadow stack on riscv https://git.kernel.org/riscv/c/6b8214c8cbd6
• [v23,28/28] kselftest/riscv: kselftest for user mode cfi https://git.kernel.org/riscv/c/0f226cf6026f

As I noted with the SSE series (before we removed it from for-next), I may not ultimately send this in a PR this merge window, for several reasons. The series has been around for a while, and although I know some vendors have tested it privately, I'd really like to have more public testing of this code, particularly on hardware emulation platforms or unreleased silicon. It would be good to see some Tested-by:s.

Thanks to everyone who has helped test this so far over the past few weeks - particularly Joel Stanley of TensTorrent.

- Paul