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Message-Id: <0320e5b41a794fd456ab8c5993bbfadcf9e1d8b4.1621516826.git.christophe.leroy@csgroup.eu>
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From:   Christophe Leroy <christophe.leroy@csgroup.eu>
Subject: [PATCH v2 01/12] powerpc/inst: Fix sparse detection on
 get_user_instr()
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        naveen.n.rao@linux.vnet.ibm.com, jniethe5@gmail.com
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Date:   Thu, 20 May 2021 13:50:38 +0000 (UTC)
Precedence: bulk

get_user_instr() lacks sparse detection for the __user tag.

This is because __gui_ptr is assigned with a cast.

Fix that by adding a __chk_user_ptr()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/inst.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 268d3bd073c8..887ef150fdda 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -12,6 +12,8 @@
 	unsigned long __gui_ptr = (unsigned long)ptr;			\
 	struct ppc_inst __gui_inst;					\
 	unsigned int __prefix, __suffix;				\
+									\
+	__chk_user_ptr(ptr);						\
 	__gui_ret = gu_op(__prefix, (unsigned int __user *)__gui_ptr);	\
 	if (__gui_ret == 0) {						\
 		if ((__prefix >> 26) == OP_PREFIX) {			\
@@ -29,7 +31,10 @@
 })
 #else /* !CONFIG_PPC64 */
 #define ___get_user_instr(gu_op, dest, ptr)				\
-	gu_op((dest).val, (u32 __user *)(ptr))
+({									\
+	__chk_user_ptr(ptr);						\
+	gu_op((dest).val, (u32 __user *)(ptr));				\
+})
 #endif /* CONFIG_PPC64 */
 
 #define get_user_instr(x, ptr) \
-- 
2.25.0