| Message ID | 20231122-arm64-gcs-v7-9-201c483bd775@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v7,01/39] arm64/mm: Restructure arch_validate_flags() for extensibility | expand |
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 22e10e79f56a..e118c3d772c8 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -445,6 +445,24 @@ static inline int gcssttr(unsigned long __user *addr, unsigned long val) return err; } +static inline void put_user_gcs(unsigned long val, unsigned long __user *addr, + int *err) +{ + int ret; + + if (!access_ok((char __user *)addr, sizeof(u64))) { + *err = -EFAULT; + return; + } + + uaccess_ttbr0_enable(); + ret = gcssttr(addr, val); + if (ret != 0) + *err = ret; + uaccess_ttbr0_disable(); +} + + #endif /* CONFIG_ARM64_GCS */ #endif /* __ASM_UACCESS_H */
In order for EL1 to write to an EL0 GCS it must use the GCSSTTR instruction rather than a normal STTR. Provide a put_user_gcs() which does this. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/asm/uaccess.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)