On Sun, Nov 13, 2022 at 03:47:38PM -0600, Samuel Holland wrote: > 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>
Aah, I missed that case. I supposed the strings always match the pattern stated in riscv cpus binding [1], the detection logic here needs to be updated once the case is also allowed. [1] https://github.com/torvalds/linux/blob/v6.1-rc5/Documentation/devicetree/bindings/riscv/cpus.yaml#L83 Thanks for your review! Best regards, Peter Lin > > > + for (i = 4; i < sizeof(desc); i++) { > > + if (desc[i] == '_' || desc[i] == '\0') > > + break; > > + if (desc[i] == ext) > > + return true; > > + } > > } > > > > return false; >