[PATCH -next v6 04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO

From: Tong Tiangen <tongtiangen@huawei.com>
To: Mark Rutland <mark.rutland@arm.com>,
	James Morse <james.morse@arm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Robin Murphy <robin.murphy@arm.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>, <x86@kernel.org>,
	"H . Peter Anvin" <hpa@zytor.com>
Cc: <linuxppc-dev@lists.ozlabs.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Xie XiuQi <xiexiuqi@huawei.com>, Guohanjun <guohanjun@huawei.com>,
	Tong Tiangen <tongtiangen@huawei.com>
Subject: [PATCH -next v6 04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO
Date: Tue, 21 Jun 2022 07:26:32 +0000	[thread overview]
Message-ID: <20220621072638.1273594-5-tongtiangen@huawei.com> (raw)
In-Reply-To: <20220621072638.1273594-1-tongtiangen@huawei.com>

Currnetly, the extable type used by __arch_copy_from/to_user() is
EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful
EX_TYPE_UACCESS_*.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  8 ++++++++
 arch/arm64/include/asm/asm-uaccess.h | 12 ++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 2e1e6bc33bcd..73266553f8a2 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -63,6 +63,14 @@
 	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
+/*
+ * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
+ * when an unhandled fault is taken.
+ */
+	.macro          _asm_extable_uaccess, insn, fixup
+	_ASM_EXTABLE_UACCESS(\insn, \fixup)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
index 0557af834e03..75b211c98dea 100644
--- a/arch/arm64/include/asm/asm-uaccess.h
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -61,7 +61,7 @@ alternative_else_nop_endif
 
 #define USER(l, x...)				\
 9999:	x;					\
-	_asm_extable	9999b, l
+	_asm_extable_uaccess	9999b, l
 
 /*
  * Generate the assembly for LDTR/STTR with exception table entries.
@@ -73,8 +73,8 @@ alternative_else_nop_endif
 8889:		ldtr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b, \l;
+		_asm_extable_uaccess	8889b, \l;
 	.endm
 
 	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -82,14 +82,14 @@ alternative_else_nop_endif
 8889:		sttr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b,\l;
+		_asm_extable_uaccess	8889b,\l;
 	.endm
 
 	.macro user_ldst l, inst, reg, addr, post_inc
 8888:		\inst		\reg, [\addr];
 		add		\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
+		_asm_extable_uaccess	8888b, \l;
 	.endm
 #endif
-- 
2.25.1

