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From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, "H . J . Lu" <hjl.tools@gmail.com>,
	Andi Kleen <ak@linux.intel.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [RFC 5/9] x86/mm: Provide untagged_addr() helper
Date: Fri,  5 Feb 2021 18:16:26 +0300	[thread overview]
Message-ID: <20210205151631.43511-7-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20210205151631.43511-1-kirill.shutemov@linux.intel.com>

The helper used by the core-mm to strip tag bits and get the address to
the canonical shape. In only handles userspace addresses.

For LAM, the address gets sanitized according to the thread flags.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/include/asm/page_32.h |  3 +++
 arch/x86/include/asm/page_64.h | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/page_32.h b/arch/x86/include/asm/page_32.h
index 94dbd51df58f..a829c46ab977 100644
--- a/arch/x86/include/asm/page_32.h
+++ b/arch/x86/include/asm/page_32.h
@@ -15,6 +15,9 @@ extern unsigned long __phys_addr(unsigned long);
 #define __phys_addr_symbol(x)	__phys_addr(x)
 #define __phys_reloc_hide(x)	RELOC_HIDE((x), 0)
 
+#define untagged_addr(addr)	(addr)
+#define untagged_ptr(ptr)	(ptr)
+
 #ifdef CONFIG_FLATMEM
 #define pfn_valid(pfn)		((pfn) < max_mapnr)
 #endif /* CONFIG_FLATMEM */
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 939b1cff4a7b..67cb434efdf6 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -56,6 +56,25 @@ static inline void clear_page(void *page)
 
 void copy_page(void *to, void *from);
 
+#define __untagged_addr(addr, n)	\
+	((__force __typeof__(addr))sign_extend64((__force u64)(addr), n))
+
+#define untagged_addr(addr)	({					\
+	u64 __addr = (__force u64)(addr);				\
+	if (__addr >> 63 == 0) {					\
+		if (test_thread_flag(TIF_LAM_U57))			\
+			__addr &= __untagged_addr(__addr, 56);		\
+		else if (test_thread_flag(TIF_LAM_U48))			\
+			__addr &= __untagged_addr(__addr, 47);		\
+	}								\
+	(__force __typeof__(addr))__addr;				\
+})
+
+#define untagged_ptr(ptr)	({					\
+	u64 __ptrval = (__force u64)(ptr);				\
+	__ptrval = untagged_addr(__ptrval);				\
+	(__force __typeof__(*(ptr)) *)__ptrval;				\
+})
 #endif	/* !__ASSEMBLY__ */
 
 #ifdef CONFIG_X86_VSYSCALL_EMULATION
-- 
2.26.2



  parent reply	other threads:[~2021-02-05 15:17 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-05 15:16 [RFC 0/9] Linear Address Masking enabling Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 1/9] mm, arm64: Update PR_SET/GET_TAGGED_ADDR_CTRL interface Kirill A. Shutemov
2021-02-11 16:57   ` Catalin Marinas
2021-02-11 17:06     ` Dave Hansen
2021-02-11 18:26       ` Catalin Marinas
2021-02-05 15:16 ` [QEMU] x86: Implement Linear Address Masking support Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 2/9] x86/mm: Fix CR3_ADDR_MASK Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 3/9] x86: CPUID and CR3/CR4 flags for Linear Address Masking Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 4/9] x86/mm: Introduce TIF_LAM_U57 and TIF_LAM_U48 Kirill A. Shutemov
2021-02-05 15:16 ` Kirill A. Shutemov [this message]
2021-02-05 15:16 ` [RFC 6/9] x86/uaccess: Remove tags from the address before checking Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 7/9] x86/mm: Handle tagged memory accesses from kernel threads Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 8/9] x86/mm: Make LAM_U48 and mappings above 47-bits mutually exclusive Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 9/9] x86/mm: Implement PR_SET/GET_TAGGED_ADDR_CTRL with LAM Kirill A. Shutemov
2021-02-05 15:42   ` H.J. Lu
2021-02-07  8:07     ` Dmitry Vyukov
2021-02-07 14:09       ` Kirill A. Shutemov
2021-02-07 14:11         ` Dmitry Vyukov
2021-02-05 15:16 ` [QEMU] x86: Implement Linear Address Masking support Kirill A. Shutemov
2021-02-05 15:49 ` [RFC 0/9] Linear Address Masking enabling Peter Zijlstra
2021-02-05 16:01   ` Kirill A. Shutemov
2021-02-05 16:19     ` Peter Zijlstra
2021-02-07  8:24 ` Dmitry Vyukov
2021-02-07 14:11   ` Kirill A. Shutemov
2021-09-21 16:52     ` Dmitry Vyukov
2021-09-21 17:15       ` H.J. Lu
2021-09-22  1:15         ` Zhang, Xiang1
2021-09-22 12:54           ` Dmitry Vyukov
2021-09-22 20:03             ` Dmitry Vyukov
2021-09-22 21:33               ` Kirill A. Shutemov
2021-09-23  0:15               ` H.J. Lu
2021-09-23  5:35                 ` Dmitry Vyukov
2021-09-23  0:07             ` H.J. Lu

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