@@ -1,53 +1,36 @@
From 71c356a07fbbf1530cfc87960e975f93bc9007e8 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Tue, 22 Jul 2025 09:46:03 -0700
-Subject: [PATCH] Use libc::SYS_futex_time64 on riscv32
+Subject: [PATCH] Use getrandom syscall on riscv32/riscv64 linux
-On RISC-V 32-bit (riscv32), the SYS_futex system call is
-often handled indirectly due to the use of a 64-bit time_t
-type. Specifically, while SYS_futex is not directly defined,
-a related syscall like SYS_futex_time64 can be used,
+Minimum kernel needed on RISCV is fairly new (4.15+) so we are sure
+to have getrandom syscall, on glibc there is mimimal ABI kernel to denote
+it but musl does not have any other way to indicate it, so add it
+as a condition here to choose getrandom backend for rv32/rv64 on linux
+when using musl.
-Upstream-Status: Submitted [https://github.com/rust-random/getrandom/pull/698]
+Upstream-Status: Backport [https://github.com/rust-random/getrandom/pull/699]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
src/backends/use_file.rs | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
-diff --git a/src/backends/use_file.rs b/src/backends/use_file.rs
-index 7b48d43..baa0c66 100644
---- a/src/backends/use_file.rs
-+++ b/src/backends/use_file.rs
-@@ -158,7 +158,18 @@ mod sync {
- pub(super) fn wait() {
- let op = libc::FUTEX_WAIT | libc::FUTEX_PRIVATE_FLAG;
- let timeout_ptr = core::ptr::null::<libc::timespec>();
-+ #[cfg(not(target_arch = "riscv32"))]
- let ret = unsafe { libc::syscall(libc::SYS_futex, &FD, op, FD_ONGOING_INIT, timeout_ptr) };
-+ #[cfg(target_arch = "riscv32")]
-+ let ret = unsafe {
-+ libc::syscall(
-+ libc::SYS_futex_time64,
-+ &FD,
-+ op,
-+ FD_ONGOING_INIT,
-+ timeout_ptr,
-+ )
-+ };
- // FUTEX_WAIT should return either 0 or EAGAIN error
- debug_assert!({
- match ret {
-@@ -172,7 +183,13 @@ mod sync {
- /// Wake up all threads which wait for value of atomic `FD` to change.
- pub(super) fn wake() {
- let op = libc::FUTEX_WAKE | libc::FUTEX_PRIVATE_FLAG;
-+
-+ #[cfg(not(target_arch = "riscv32"))]
- let ret = unsafe { libc::syscall(libc::SYS_futex, &FD, op, libc::INT_MAX) };
-+
-+ #[cfg(target_arch = "riscv32")]
-+ let ret = unsafe { libc::syscall(libc::SYS_futex_time64, &FD, op, libc::INT_MAX) };
-+
- debug_assert!(ret >= 0);
- }
-
+--- a/src/backends.rs
++++ b/src/backends.rs
+@@ -93,7 +93,15 @@ cfg_if! {
+ // Minimum supported Linux kernel version for MUSL targets
+ // is not specified explicitly (as of Rust 1.77) and they
+ // are used in practice to target pre-3.17 kernels.
+- target_env = "musl",
++ all(
++ target_env = "musl",
++ not(
++ any(
++ target_arch = "riscv64",
++ target_arch = "riscv32",
++ ),
++ ),
++ ),
+ ),
+ )
+ ))] {
@@ -1,66 +1,51 @@
-From 78d4c37e9c5b60ea2368627c2fc297dfc46bec2a Mon Sep 17 00:00:00 2001
+From 7ebddca7070742bbb9cce471a93d699ad70ee371 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Tue, 22 Jul 2025 10:15:06 -0700
-Subject: [PATCH] Use libc::SYS_futex_time64 on riscv32
+Subject: [PATCH] Use libc::SYS_futex_time64 on riscv32/musl
On RISC-V 32-bit (riscv32), the SYS_futex system call is
often handled indirectly due to the use of a 64-bit time_t
type. Specifically, while SYS_futex is not directly defined,
-a related syscall like SYS_futex_time64 can be used,
+a related syscall like SYS_futex_time64 can be used on target
+e.g. riscv32
Upstream-Status: Submitted [https://github.com/Amanieu/parking_lot/pull/485]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
- src/thread_parker/linux.rs | 19 +++++++++++++++++++
- 1 file changed, 19 insertions(+)
+ src/thread_parker/linux.rs | 13 +++++++++++--
+ 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/src/thread_parker/linux.rs b/src/thread_parker/linux.rs
-index 92601f6..3695624 100644
+index 92601f6..0952db4 100644
--- a/src/thread_parker/linux.rs
+++ b/src/thread_parker/linux.rs
-@@ -108,6 +108,7 @@ impl ThreadParker {
+@@ -108,9 +108,13 @@ impl ThreadParker {
.as_ref()
.map(|ts_ref| ts_ref as *const _)
.unwrap_or(ptr::null());
-+ #[cfg(not(target_arch = "riscv32"))]
++ #[cfg(not(all(target_arch = "riscv32", target_env = "musl")))]
++ let futex_num = libc::SYS_futex;
++ #[cfg(all(target_arch = "riscv32", target_env = "musl",))]
++ let futex_num = libc::SYS_futex_time64;
let r = unsafe {
libc::syscall(
- libc::SYS_futex,
-@@ -117,6 +118,16 @@ impl ThreadParker {
- ts_ptr,
- )
- };
-+ #[cfg(target_arch = "riscv32")]
-+ let r = unsafe {
-+ libc::syscall(
-+ libc::SYS_futex_time64,
-+ &self.futex,
-+ libc::FUTEX_WAIT | libc::FUTEX_PRIVATE_FLAG,
-+ 1,
-+ ts_ptr,
-+ )
-+ };
- debug_assert!(r == 0 || r == -1);
- if r == -1 {
- debug_assert!(
-@@ -137,12 +148,20 @@ impl super::UnparkHandleT for UnparkHandle {
+- libc::SYS_futex,
++ futex_num,
+ &self.futex,
+ libc::FUTEX_WAIT | libc::FUTEX_PRIVATE_FLAG,
+ 1,
+@@ -137,8 +141,13 @@ impl super::UnparkHandleT for UnparkHandle {
unsafe fn unpark(self) {
// The thread data may have been freed at this point, but it doesn't
// matter since the syscall will just return EFAULT in that case.
-+ #[cfg(not(target_arch = "riscv32"))]
++ #[cfg(not(all(target_arch = "riscv32", target_env = "musl",)))]
++ let futex_num = libc::SYS_futex;
++ #[cfg(all(target_arch = "riscv32", target_env = "musl",))]
++ let futex_num = libc::SYS_futex_time64;
++
let r = libc::syscall(
- libc::SYS_futex,
+- libc::SYS_futex,
++ futex_num,
self.futex,
libc::FUTEX_WAKE | libc::FUTEX_PRIVATE_FLAG,
1,
- );
-+ #[cfg(target_arch = "riscv32")]
-+ let r = libc::syscall(
-+ libc::SYS_futex_time64,
-+ self.futex,
-+ libc::FUTEX_WAKE | libc::FUTEX_PRIVATE_FLAG,
-+ 1,
-+ );
- debug_assert!(r == 0 || r == 1 || r == -1);
- if r == -1 {
- debug_assert_eq!(errno(), libc::EFAULT);
getrandom patch is accepted upstream with minor changes parking_lot patch has addressed upstream feedback Signed-off-by: Khem Raj <raj.khem@gmail.com> --- ...Use-libc-SYS_futex_time64-on-riscv32.patch | 69 +++++++------------ ...Use-libc-SYS_futex_time64-on-riscv32.patch | 65 +++++++---------- 2 files changed, 51 insertions(+), 83 deletions(-)