[PATCH 2/2] linux: use __getrandom_nocancel in getentropy

[Adhemerval Zanella Netto]

On 08/02/25 14:05, Cristian Rodríguez wrote:
> It must use the VDSO implementation if available instead of a raw
> syscall.
> 
> Signed-off-by: Cristian Rodríguez <cristian@rodriguez.im>

I think it make sense now that we have an non-cancellable internal symbol,
and the vDSO should give us same guarantee as the kernel.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  sysdeps/unix/sysv/linux/getentropy.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/getentropy.c b/sysdeps/unix/sysv/linux/getentropy.c
> index a62c9fb099..2134a32ae4 100644
> --- a/sysdeps/unix/sysv/linux/getentropy.c
> +++ b/sysdeps/unix/sysv/linux/getentropy.c
> @@ -21,7 +21,7 @@
>  #include <errno.h>
>  #include <unistd.h>
>  #include <sysdep.h>
> -
> +#include <not-cancel.h>
>  /* Write LENGTH bytes of randomness starting at BUFFER.  Return 0 on
>     success and -1 on failure.  */
>  int
> @@ -42,7 +42,7 @@ getentropy (void *buffer, size_t length)
>    while (buffer < end)
>      {
>        /* NB: No cancellation point.  */
> -      ssize_t bytes = INLINE_SYSCALL_CALL (getrandom, buffer, end - buffer, 0);
> +      ssize_t bytes = __getrandom_nocancel (buffer, end - buffer, 0);
>        if (bytes < 0)
>          {
>            if (errno == EINTR)