----- On Feb 26, 2021, at 8:51 AM, Piotr Figiel fig...@google.com wrote:
[...]
> ---
> v2:
> Applied review comments:
> - changed return value from the ptrace request to the size of the
> configuration structure
> - expanded configuration structure with the flags field and
> the rseq abi structure size
>
[...]
> +#define PTRACE_GET_RSEQ_CONFIGURATION 0x420f
> +
> +struct ptrace_rseq_configuration {
> + __u64 rseq_abi_pointer;
> + __u32 rseq_abi_size;
> + __u32 signature;
> + __u32 flags;
> + __u32 pad;
> +};
> +
[...]
> +#ifdef CONFIG_RSEQ
> +static long ptrace_get_rseq_configuration(struct task_struct *task,
> + unsigned long size, void __user *data)
> +{
> + struct ptrace_rseq_configuration conf = {
> + .rseq_abi_pointer = (u64)(uintptr_t)task->rseq,
> + .rseq_abi_size = sizeof(*task->rseq),
> + .signature = task->rseq_sig,
> + .flags = 0,
> + };
> +
> + size = min_t(unsigned long, size, sizeof(conf));
> + if (copy_to_user(data, &conf, size))
> + return -EFAULT;
> + return sizeof(conf);
> +}
I think what Florian was after would be:
struct ptrace_rseq_configuration {
__u32 size; /* size of struct ptrace_rseq_configuration */
__u32 flags;
__u64 rseq_abi_pointer;
__u32 signature;
__u32 pad;
};
where:
.size = sizeof(struct ptrace_rseq_configuration),
This way, the configuration structure can be expanded in the future. The
rseq ABI structure is by definition fixed-size, so there is no point in
having its size here.
Florian, did I understand your request correctly, or am I missing your point ?
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
