[PATCH] riscv: fix incorrect use of __user pointer

Clément Léger cleger at rivosinc.com
Wed Nov 22 05:51:41 PST 2023


These warnings were reported by sparse and were due to lack of __user
annotation as well as dereferencing such pointer. Fix this by adding
__user cast were needed (load_u8()/store_u8()) and move the __user
annotation in __read_insn() into the if() branch that uses __get_user()
with this pointer.

Reported-by: kernel test robot <lkp at intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311160606.obGOOwB3-lkp@intel.com/
Signed-off-by: Clément Léger <cleger at rivosinc.com>
---
 arch/riscv/kernel/traps_misaligned.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
index 5eba37147caa..02abb6616873 100644
--- a/arch/riscv/kernel/traps_misaligned.c
+++ b/arch/riscv/kernel/traps_misaligned.c
@@ -319,7 +319,7 @@ static inline int get_insn(struct pt_regs *regs, ulong mepc, ulong *r_insn)
 static inline int load_u8(struct pt_regs *regs, const u8 *addr, u8 *r_val)
 {
 	if (user_mode(regs)) {
-		return __get_user(*r_val, addr);
+		return __get_user(*r_val, (u8 __user *)addr);
 	} else {
 		*r_val = *addr;
 		return 0;
@@ -329,7 +329,7 @@ static inline int load_u8(struct pt_regs *regs, const u8 *addr, u8 *r_val)
 static inline int store_u8(struct pt_regs *regs, u8 *addr, u8 val)
 {
 	if (user_mode(regs)) {
-		return __put_user(val, addr);
+		return __put_user(val, (u8 __user *)addr);
 	} else {
 		*addr = val;
 		return 0;
@@ -341,7 +341,7 @@ static inline int store_u8(struct pt_regs *regs, u8 *addr, u8 val)
 	int __ret;					\
 							\
 	if (user_mode(regs)) {				\
-		__ret = __get_user(insn, insn_addr);	\
+		__ret = __get_user(insn, (typeof(*insn_addr) __user *) insn_addr); \
 	} else {					\
 		insn = *insn_addr;			\
 		__ret = 0;				\
@@ -356,7 +356,7 @@ static inline int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn)
 
 	if (epc & 0x2) {
 		ulong tmp = 0;
-		u16 __user *insn_addr = (u16 __user *)epc;
+		u16 *insn_addr = (u16 *)epc;
 
 		if (__read_insn(regs, insn, insn_addr))
 			return -EFAULT;
@@ -376,7 +376,7 @@ static inline int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn)
 
 		return 0;
 	} else {
-		u32 __user *insn_addr = (u32 __user *)epc;
+		u32 *insn_addr = (u32 *)epc;
 
 		if (__read_insn(regs, insn, insn_addr))
 			return -EFAULT;
-- 
2.42.0




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