[PATCH v11 09/39] arm64/gcs: Provide put_user_gcs()
From: Mark Brown <broonie@kernel.org>
Date: 2024-08-22 01:17:51
Also in:
kvmarm, linux-arch, linux-doc, linux-fsdevel, linux-kselftest, linux-mm, linux-riscv, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
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. Reviewed-by: Thiago Jung Bauermann <redacted> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/asm/uaccess.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 6aba10e38d1c..ecdd47cf1d01 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h@@ -522,6 +522,24 @@ 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 */
--
2.39.2