Re: [PATCH v2 2/2] arm64: uaccess: Implement unsafe accessors
flat view
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2018-12-06 18:25:58
Also in:
lkml
On Mon, Dec 03, 2018 at 01:55:18PM +0000, Julien Thierry wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 07c3408..cabfcae 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h@@ -233,6 +233,23 @@ static inline void uaccess_enable_not_uao(void) __uaccess_enable(ARM64_ALT_PAN_NOT_UAO); } +#define unsafe_user_region_active uaccess_region_active +static inline bool uaccess_region_active(void) +{ + if (system_uses_ttbr0_pan()) { + u64 ttbr; + + ttbr = read_sysreg(ttbr1_el1); + return ttbr & TTBR_ASID_MASK;
Nitpick: could write this in 1-2 lines.
quoted hunk ↗ jump to hunk
+ } else if (cpus_have_const_cap(ARM64_ALT_PAN_NOT_UAO)) { + return (read_sysreg(sctlr_el1) & SCTLR_EL1_SPAN) ? + false : + !read_sysreg_s(SYS_PSTATE_PAN); + }
ARM64_ALT_PAN_NOT_UAO implies ARM64_HAS_PAN which implies SCTLR_EL1.SPAN is 0 at run-time. Is this to cope with the case of being called prior to cpu_enable_pan()? -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel