std::rand::OsRng: Use getrandom syscall on Linux
#18664
Conversation
|
|
| : "{rax}"(GETRANDOM), "{rdi}"(buf.as_ptr()), "{rsi}"(buf.len()), "{rdx}"(flags) | ||
| : "rcx", "r11", "memory" | ||
| : "volatile"); | ||
| } |
There was a problem hiding this comment.
Instead of using inline assembly, could this use the extern_weak trick that __pthread_get_minstack uses?
There was a problem hiding this comment.
That may end up simplifying a large amount of what's going on here as well...
There was a problem hiding this comment.
There's no symbol for getrandom at all yet. Using syscall to call it would work.
There was a problem hiding this comment.
Ah ok, using syscall sounds like it would work just as well!
|
@klutzy: I think this should use |
|
Rust supports calls to variadic C functions so it should work fine. |
| ret | ||
| } | ||
|
|
||
| #[cfg(not(any(target_os = "linux", target_arch = "x86_64", target_arch = "x86")))] |
There was a problem hiding this comment.
What happens to ARM Linux?
I think this line should be
#[cfg(not(all(target_os = "linux", any(target_arch = "x86", target_arch = "x86_64"))))]
Ah, if you switch to the variadic syscall(2), it should take care of ENOSYS
`getrandom(2)` system call [1] has been added on Linux 3.17. This patch makes `OsRng` use `getrandom` if available, and use traditional `/dev/urandom` fallback if not. [1]: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c6e9d6f38894798696f23c8084ca7edbf16ee895
|
updated with @nodakai Added arm-eabi (syscall number 384), although I have no way to test it right now. |
getrandom(2)system call 1 has been added on Linux 3.17.This patch makes
OsRngusegetrandomif available, and usetraditional
/dev/urandomfallback if not.Fixes #17922.