On Mon, Oct 07, 2019 at 06:06:35PM +0800, Yunfeng Ye wrote:
> There are no return value checking when using kzalloc() and kcalloc() for
> memory allocation. so add it.
>
> Signed-off-by: Yunfeng Ye <yeyunf...@huawei.com>
> ---
> v1 -> v2:
> - return error code when memory allocation failure
>
> arch/arm64/kernel/armv8_deprecated.c | 57
> +++++++++++++++++++++++++++---------
> 1 file changed, 43 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm64/kernel/armv8_deprecated.c
> b/arch/arm64/kernel/armv8_deprecated.c
> index 2ec09de..2284fcb 100644
> --- a/arch/arm64/kernel/armv8_deprecated.c
> +++ b/arch/arm64/kernel/armv8_deprecated.c
> @@ -168,12 +168,15 @@ static int update_insn_emulation_mode(struct
> insn_emulation *insn,
> return ret;
> }
>
> -static void __init register_insn_emulation(struct insn_emulation_ops *ops)
> +static int __init register_insn_emulation(struct insn_emulation_ops *ops)
> {
> unsigned long flags;
> struct insn_emulation *insn;
>
> insn = kzalloc(sizeof(*insn), GFP_KERNEL);
> + if (!insn)
> + return -ENOMEM;
> +
> insn->ops = ops;
> insn->min = INSN_UNDEF;
>
> @@ -197,6 +200,7 @@ static void __init register_insn_emulation(struct
> insn_emulation_ops *ops)
>
> /* Register any handlers if required */
> update_insn_emulation_mode(insn, INSN_UNDEF);
> + return 0;
> }
>
> static int emulation_proc_handler(struct ctl_table *table, int write,
> @@ -224,7 +228,7 @@ static int emulation_proc_handler(struct ctl_table
> *table, int write,
> return ret;
> }
>
> -static void __init register_insn_emulation_sysctl(void)
> +static int __init register_insn_emulation_sysctl(void)
> {
> unsigned long flags;
> int i = 0;
> @@ -233,6 +237,8 @@ static void __init register_insn_emulation_sysctl(void)
>
> insns_sysctl = kcalloc(nr_insn_emulated + 1, sizeof(*sysctl),
> GFP_KERNEL);
> + if (!insns_sysctl)
> + return -ENOMEM;
>
> raw_spin_lock_irqsave(&insn_emulation_lock, flags);
> list_for_each_entry(insn, &insn_emulation, node) {
> @@ -251,6 +257,7 @@ static void __init register_insn_emulation_sysctl(void)
> raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
>
> register_sysctl("abi", insns_sysctl);
> + return 0;
> }
>
> /*
> @@ -617,25 +624,47 @@ static int t16_setend_handler(struct pt_regs *regs, u32
> instr)
> */
> static int __init armv8_deprecated_init(void)
> {
> - if (IS_ENABLED(CONFIG_SWP_EMULATION))
> - register_insn_emulation(&swp_ops);
> + int ret = 0;
> + int err = 0;
> +
> + if (IS_ENABLED(CONFIG_SWP_EMULATION)) {
> + ret = register_insn_emulation(&swp_ops);
> + if (ret) {
> + pr_err("register insn emulation swp: fail\n");
> + err = ret;
> + }
> + }
Is there much point in continuing here? May as well just return ret, I
think. I also don't think you need to print anything, since kmalloc
should already have shouted.
> - if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
> - register_insn_emulation(&cp15_barrier_ops);
> + if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION)) {
> + ret = register_insn_emulation(&cp15_barrier_ops);
> + if (ret) {
> + pr_err("register insn emulation cpu15_barrier: fail\n");
> + err = ret;
> + }
> + }
>
> if (IS_ENABLED(CONFIG_SETEND_EMULATION)) {
> - if(system_supports_mixed_endian_el0())
> - register_insn_emulation(&setend_ops);
> - else
> + if (system_supports_mixed_endian_el0()) {
> + ret = register_insn_emulation(&setend_ops);
> + if (ret) {
> + pr_err("register insn emulation setend:
> fail\n");
> + err = ret;
> + }
> + } else {
> pr_info("setend instruction emulation is not supported
> on this system\n");
> + }
> }
>
> - cpuhp_setup_state_nocalls(CPUHP_AP_ARM64_ISNDEP_STARTING,
> - "arm64/isndep:starting",
> - run_all_insn_set_hw_mode, NULL);
> - register_insn_emulation_sysctl();
> + if (nr_insn_emulated) {
> + cpuhp_setup_state_nocalls(CPUHP_AP_ARM64_ISNDEP_STARTING,
> + "arm64/isndep:starting",
> + run_all_insn_set_hw_mode, NULL);
> + ret = register_insn_emulation_sysctl();
> + if (ret)
> + err = ret;
> + }
I'm dubious about leaving the cpuhp notifier registered if we fail here.
Can we simply reorder the logic so that the notifier is registered after
successfully calling register_insn_emulation_sysctl()?
Will
