Subject: [PATCH AUTOSEL 5.13 073/114] powerpc/inst: Fix sparse detection on get_user_instr()

From: Sasha Levin <[email-masked]>
Date: Fri, 9 Jul 2021 22:17:07 -0400

From: Christophe Leroy <[email-masked]>

[ Upstream commit b3a9e523237013477bea914b7fbfbe420428b988 ]

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 <[email-masked]>
Signed-off-by: Michael Ellerman <[email-masked]>
Link: https://lore.kernel.org/r/0320e5b4[email-masked]
Signed-off-by: Sasha Levin <[email-masked]>
---
 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) \
-- 
2.30.2