Replace sprintf() with sysfs_emit() in cpu_show_ghostwrite(), which is
preferred for formatting sysfs output because it provides safer bounds
checking.
While the current code only emits fixed strings that fit easily within
PAGE_SIZE, use sysfs_emit() to follow secure coding best practices.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20260510165420.109453-3-thorsten.blum@linux.dev
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Follow the patterns of the other architectures that use
GENERIC_CPU_VULNERABILITIES for riscv to introduce the ghostwrite
vulnerability and mitigation. The mitigation is to disable all vector
which is accomplished by clearing the bit from the cpufeature field.
Ghostwrite only affects thead c9xx CPUs that impelment xtheadvector, so
the vulerability will only be mitigated on these CPUs.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Yangyu Chen <cyy@cyyself.name>
Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-14-236c22791ef9@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
