Hi, Jens,
Jens Axboe <axboe@xxxxxxxxx> writes:
> Add compat.h include to avoid a potential build issue:
>
> io_uring/register.c:281:6: error: call to undeclared function 'in_compat_syscall'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
>
> if (in_compat_syscall()) {
> ^
> 1 warning generated.
> io_uring/register.c:282:9: error: call to undeclared function 'compat_get_bitmap'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
> ret = compat_get_bitmap(cpumask_bits(new_mask),
> ^
>
> Fixes: c43203154d8a ("io_uring/register: move io_uring_register(2) related code to register.c")
> Reported-by: Manu Bretelle <chantra@xxxxxxxx>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>
> ---
>
> diff --git a/io_uring/register.c b/io_uring/register.c
> index 708dd1d89add..5e62c1208996 100644
> --- a/io_uring/register.c
> +++ b/io_uring/register.c
> @@ -14,6 +14,7 @@
> #include <linux/slab.h>
> #include <linux/uaccess.h>
> #include <linux/nospec.h>
> +#include <linux/compat.h>
> #include <linux/io_uring.h>
> #include <linux/io_uring_types.h>
This makes sense to me, but I wasn't able to reproduce that build error
after disabling CONFIG_COMPAT.
> @@ -278,13 +279,14 @@ static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx,
> if (len > cpumask_size())
> len = cpumask_size();
>
> - if (in_compat_syscall()) {
> +#ifdef CONFIG_COMPAT
> + if (in_compat_syscall())
I don't think this is needed.
linux/compat.h:
...
#else /* !CONFIG_COMPAT */
#define is_compat_task() (0)
/* Ensure no one redefines in_compat_syscall() under !CONFIG_COMPAT */
#define in_compat_syscall in_compat_syscall
static inline bool in_compat_syscall(void) { return false; }
Isn't the code fine as-is?
-Jeff
> ret = compat_get_bitmap(cpumask_bits(new_mask),
> (const compat_ulong_t __user *)arg,
> len * 8 /* CHAR_BIT */);
> - } else {
> + else
> +#endif
> ret = copy_from_user(new_mask, arg, len);
> - }
>
> if (ret) {
> free_cpumask_var(new_mask);
