Re: [PATCH v2 1/2] ARM: Fix some check warnings of tool sparse

From: Ard Biesheuvel
Date: Mon Oct 10 2022 - 06:20:56 EST


On Mon, 10 Oct 2022 at 11:56, Zhen Lei <thunder.leizhen@xxxxxxxxxx> wrote:
>
> Fix the following warnings:
> warning: incorrect type in initializer (different address spaces)
> expected unsigned short [noderef] __user *register __p
> got unsigned short [usertype] *
> warning: cast removes address space '__user' of expression
>
> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
> ---
> arch/arm/kernel/traps.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
> index 20b2db6dcd1ced7..34aa80c09c508c1 100644
> --- a/arch/arm/kernel/traps.c
> +++ b/arch/arm/kernel/traps.c
> @@ -188,9 +188,9 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
> }
> } else {
> if (thumb)
> - bad = get_user(val, &((u16 *)addr)[i]);
> + bad = get_user(val, &((u16 __user *)addr)[i]);
> else
> - bad = get_user(val, &((u32 *)addr)[i]);
> + bad = get_user(val, &((u32 __user *)addr)[i]);
> }
>
> if (!bad)
> @@ -455,15 +455,15 @@ asmlinkage void do_undefinstr(struct pt_regs *regs)
> if (processor_mode(regs) == SVC_MODE) {
> #ifdef CONFIG_THUMB2_KERNEL
> if (thumb_mode(regs)) {
> - instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
> + instr = __mem_to_opcode_thumb16(((__force u16 *)pc)[0]);

Shouldn't this be __user as well? (and below)

> if (is_wide_instruction(instr)) {
> u16 inst2;
> - inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]);
> + inst2 = __mem_to_opcode_thumb16(((__force u16 *)pc)[1]);
> instr = __opcode_thumb32_compose(instr, inst2);
> }
> } else
> #endif
> - instr = __mem_to_opcode_arm(*(u32 *) pc);
> + instr = __mem_to_opcode_arm(*(__force u32 *) pc);
> } else if (thumb_mode(regs)) {
> if (get_user(instr, (u16 __user *)pc))
> goto die_sig;
> --
> 2.25.1
>
>
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