The vdso_cfi build process copies source files (*.c, *.S) from the main
vdso directory to the build directory. Without a .gitignore file, these
copied files appear as untracked files in git status, cluttering the
working directory.
Add a .gitignore file to exclude:
- Copied source files (*.c, *.S)
- Temporary build files (vdso.lds, *.tmp, vdso-syms.S)
- While preserving vdso-cfi.S which is the original entry point
This follows the same pattern used in the main vdso directory
and keeps the working directory clean.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Link: https://patch.msgid.link/20260320021850.1877-3-cp0613@linux.alibaba.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
When building VDSO with CFI support, source files are copied from the main
VDSO directory to the CFI build directory as part of the build process.
However, these copied source files were not removed during 'make clean',
leaving temporary files in the build directory.
Add the clean-files variable to ensure that these copied .c and .S files
are properly cleaned up. The notdir() function is used to strip the path
prefix, as clean-files expects relative file names without directory
components.
This ensures the build directory is left in a clean state after make clean.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Link: https://patch.msgid.link/20260320021850.1877-2-cp0613@linux.alibaba.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Shadow stack instructions are taken from the Zimop ISA extension,
which is mandated on RVA23. Any userspace with shadow stack
instructions in it will fault on hardware that doesn't have support
for Zimop. Thus, a shadow stack-enabled userspace can't be run on
hardware that doesn't support Zimop.
It's not known how Linux userspace providers will respond to this kind
of binary fragmentation. In order to keep kernel portable across
different hardware, 'arch/riscv/kernel/vdso_cfi' is created which has
Makefile logic to compile 'arch/riscv/kernel/vdso' sources with CFI
flags, and 'arch/riscv/kernel/vdso.c' is modified to select the
appropriate vdso depending on whether the underlying CPU implements
the Zimop extension. Since the offset of vdso symbols will change due
to having two different vdso binaries, there is added logic to include
a new generated vdso offset header and dynamically select the offset
(like for rt_sigreturn).
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Acked-by: Charles Mirabile <cmirabil@redhat.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-24-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
