On 11/5/22 01:02, Yu Chien Peter Lin wrote: > We should check the string until it hits underscore, in case it > searches for the letters in the custom extension. For example, > "rv64imac_xandes" will be treated as D extension support since > there is a "d" in "andes", resulting illegal instruction caused > by initializing FCSR. > > Signed-off-by: Yu Chien Peter Lin <peter...@andestech.com> > --- > arch/riscv/cpu/cpu.c | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c > index 52ab02519f..d34c8efce0 100644 > --- a/arch/riscv/cpu/cpu.c > +++ b/arch/riscv/cpu/cpu.c > @@ -36,6 +36,7 @@ static inline bool supports_extension(char ext) > #ifdef CONFIG_CPU > struct udevice *dev; > char desc[32]; > + int i; > > uclass_find_first_device(UCLASS_CPU, &dev); > if (!dev) { > @@ -43,9 +44,16 @@ static inline bool supports_extension(char ext) > return false; > } > if (!cpu_get_desc(dev, desc, sizeof(desc))) { > - /* skip the first 4 characters (rv32|rv64) */ > - if (strchr(desc + 4, ext)) > - return true; > + /* > + * skip the first 4 characters (rv32|rv64) and > + * check until underscore > + */
This probably works for the intended usage, but it is not guaranteed to work. Underscores are allowed even between single-letter extensions. See section 29.5 ("Underscores") of the unprivileged spec. Still, this is an improvement, so: Reviewed-by: Samuel Holland <sam...@sholland.org> > + for (i = 4; i < sizeof(desc); i++) { > + if (desc[i] == '_' || desc[i] == '\0') > + break; > + if (desc[i] == ext) > + return true; > + } > } > > return false;