uclibc: fix build, enable CI, add unstable support of 64-bit time_t

Jonah Petri · Jonah Petri · commit d234f7de419c · 2026-04-07T13:18:50.000-04:00
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -225,6 +225,9 @@ jobs:
           - target: x86_64-unknown-linux-musl
             env: { RUST_LIBC_UNSTABLE_MUSL_V1_2_3: 1 }
             artifact-tag: new-musl
+          - target: armv7-unknown-linux-uclibceabihf
+          - target: armv7-unknown-linux-uclibceabihf
+            env: { TEST_UCLIBC_TIIME64: 1 }
           # FIXME: It seems some items in `src/unix/mod.rs` aren't defined on redox actually.
           # - target: x86_64-unknown-redox
 
diff --git a/build.rs b/build.rs
@@ -123,6 +123,11 @@ fn main() {
         }
     }
 
+    let uclibc_use_time64 = env_flag("CARGO_CFG_LIBC_UNSTABLE_UCLIBC_TIME64");
+    if target_env == "uclibc" && uclibc_use_time64 {
+        set_cfg("linux_time_bits64");
+    }
+
     let linux_time_bits64 = env::var("RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64").is_ok();
     println!("cargo:rerun-if-env-changed=RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64");
     if linux_time_bits64 {
diff --git a/ci/docker/armv7-unknown-linux-uclibceabihf/Dockerfile b/ci/docker/armv7-unknown-linux-uclibceabihf/Dockerfile
@@ -14,11 +14,9 @@ RUN sed -i -E 's/(archive|security)\.ubuntu\.com/old-releases.ubuntu.com/g' \
         qemu-user \
         xz-utils
 
-RUN mkdir /toolchain
-
-RUN curl --retry 5 -L https://toolchains.bootlin.com/downloads/releases/toolchains/armv7-eabihf/tarballs/armv7-eabihf--uclibc--bleeding-edge-2021.11-1.tar.bz2 | \
-    tar xjf - -C /toolchain --strip-components=1
-RUN /toolchain/relocate-sdk.sh
+ARG TEST_UCLIBC_TIIME64
+COPY install-uclibc.sh /
+RUN /install-uclibc.sh "$TEST_UCLIBC_TIIME64"
 
 ENV PATH=$PATH:/rust/bin:/toolchain/bin \
     STAGING_DIR=/toolchain/armv7-buildroot-linux-uclibceabihf/sysroot \
diff --git a/ci/install-uclibc.sh b/ci/install-uclibc.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/bash
+#
+# Installs the appropriate uclibc toolchain into /toolchain
+
+set -eux
+
+time64="$1"
+
+if [ "${time64:-0}" != "0" ]; then
+    version='bleeding-edge-2025.08-1'
+else
+    version='bleeding-edge-2024.05-1'  # last version with 32-bit time_t
+fi
+
+mkdir /toolchain
+
+curl --retry 5 -L "https://toolchains.bootlin.com/downloads/releases/toolchains/armv7-eabihf/tarballs/armv7-eabihf--uclibc--${version}.tar.xz" | \
+tar xjf - -C /toolchain --strip-components=1
+
+/toolchain/relocate-sdk.sh
diff --git a/ci/run-docker.sh b/ci/run-docker.sh
@@ -44,6 +44,13 @@ run() {
         fi
     fi
 
+    if [[ "$run_target" = *"uclibc"* ]]; then
+        if [ -n "${TEST_UCLIBC_TIIME64:-}" ]; then 
+            build_args+=("--build-arg=TEST_UCLIBC_TIIME64=1")
+            export RUSTFLAGS="$RUSTFLAGS --cfg=libc_unstable_uclibc_time64"
+        fi
+    fi
+
     # use -f so we can use ci/ as build context
     docker build "${build_args[@]}"
 
diff --git a/libc-test/build.rs b/libc-test/build.rs
@@ -3731,6 +3731,12 @@ fn test_linux(target: &str) {
             cfg.cfg("linux_time_bits64", None);
         }
     }
+    let uclibc_use_time64 = env::var("CARGO_CFG_LIBC_UNSTABLE_UCLIBC_TIME64")
+        .map(|val| val != "0")
+        .unwrap_or(false);
+    if uclibc && uclibc_use_time64 {
+        cfg.cfg("linux_time_bits64", None);
+    }
     cfg.define("_GNU_SOURCE", None)
         // This macro re-defines fscanf,scanf,sscanf to link to the symbols that are
         // deprecated since glibc >= 2.29. This allows Rust binaries to link against
@@ -3934,8 +3940,7 @@ fn test_linux(target: &str) {
             "linux/wait.h",
             "linux/wireless.h",
             "sys/fanotify.h",
-            // <sys/auxv.h> is not present on uclibc
-            (!uclibc, "sys/auxv.h"),
+            "sys/auxv.h",
             (gnu || musl, "linux/close_range.h"),
         );
     }
@@ -4172,6 +4177,18 @@ fn test_linux(target: &str) {
             // On 64 bits the size did not change, skip only for 32 bits.
             "ptrace_syscall_info" if pointer_width == 32 => true,
 
+            "canxl_frame"
+            | "fanotify_event_info_header" // not in sys/fanotify.h in uclibc
+            | "fanotify_event_info_fid"  // not in sys/fanotify.h in uclibc
+            | "tls12_crypto_info_sm4_gcm"
+            | "tls12_crypto_info_sm4_ccm"
+            | "tls12_crypto_info_aria_gcm_128"
+            | "tls12_crypto_info_aria_gcm_256"
+                if uclibc =>
+            {
+                true
+            }
+
             _ => false,
         }
     });
@@ -4359,18 +4376,159 @@ fn test_linux(target: &str) {
             // Skip as this signal codes and trap reasons need newer headers
             "TRAP_PERF" => true,
 
-            // kernel constants not available in uclibc 1.0.34
-            "EXTPROC"
+            // constants not available in uclibc 1.0.45
+            // but defined outside the uclibc library,
+            // e.g. file format constants or kernel-defined
+            // constants.
+            "ALG_SET_KEY_BY_KEY_SERIAL"
+            | "AT_MINSIGSTKSZ"
+            | "BUS_MCEERR_AO"
+            | "BUS_MCEERR_AR"
+            | "CAN_BUS_OFF_THRESHOLD"
+            | "CAN_CTRLMODE_TDC_AUTO"
+            | "CAN_CTRLMODE_TDC_MANUAL"
+            | "CAN_ERR_CNT"
+            | "CAN_ERROR_PASSIVE_THRESHOLD"
+            | "CAN_ERROR_WARNING_THRESHOLD"
+            | "CAN_RAW_XL_FRAMES"
+            | "CANXL_HDR_SIZE"
+            | "CANXL_MAX_DLC_MASK"
+            | "CANXL_MAX_DLC"
+            | "CANXL_MAX_DLEN"
+            | "CANXL_MAX_MTU"
+            | "CANXL_MIN_DLC"
+            | "CANXL_MIN_DLEN"
+            | "CANXL_MIN_MTU"
+            | "CANXL_MTU"
+            | "CANXL_PRIO_BITS"
+            | "CANXL_PRIO_MASK"
+            | "CANXL_SEC"
+            | "CANXL_XLF"
+            | "CLOSE_RANGE_CLOEXEC"
+            | "CLOSE_RANGE_UNSHARE"
+            | "EM_ARC_A5"
+            | "EM_OPENRISC"
+            | "EM_TILEGX"
+            | "EM_TILEPRO"
+            | "EXTPROC"
+            | "FAN_ATTRIB"
+            | "FAN_AUDIT"
+            | "FAN_CREATE"
+            | "FAN_DELETE_SELF"
+            | "FAN_DELETE"
+            | "FAN_ENABLE_AUDIT"
+            | "FAN_EPIDFD"
+            | "FAN_EVENT_INFO_TYPE_DFID_NAME"
+            | "FAN_EVENT_INFO_TYPE_DFID"
+            | "FAN_EVENT_INFO_TYPE_ERROR"
+            | "FAN_EVENT_INFO_TYPE_FID"
+            | "FAN_EVENT_INFO_TYPE_NEW_DFID_NAME"
+            | "FAN_EVENT_INFO_TYPE_OLD_DFID_NAME"
+            | "FAN_EVENT_INFO_TYPE_PIDFD"
+            | "FAN_FS_ERROR"
+            | "FAN_INFO"
+            | "FAN_MARK_EVICTABLE"
+            | "FAN_MARK_FILESYSTEM"
+            | "FAN_MARK_IGNORE_SURV"
+            | "FAN_MARK_IGNORE"
+            | "FAN_MARK_INODE"
+            | "FAN_MOVE_SELF"
+            | "FAN_MOVE"
+            | "FAN_MOVED_FROM"
+            | "FAN_MOVED_TO"
+            | "FAN_NOPIDFD"
+            | "FAN_OPEN_EXEC_PERM"
+            | "FAN_OPEN_EXEC"
+            | "FAN_RENAME"
+            | "FAN_REPORT_DFID_NAME_TARGET"
+            | "FAN_REPORT_DFID_NAME"
+            | "FAN_REPORT_DIR_FID"
+            | "FAN_REPORT_FID"
+            | "FAN_REPORT_NAME"
+            | "FAN_REPORT_PIDFD"
+            | "FAN_REPORT_TARGET_FID"
+            | "FAN_REPORT_TID"
+            | "FAN_RESPONSE_INFO_AUDIT_RULE"
+            | "FAN_RESPONSE_INFO_NONE"
+            | "IFF_NO_CARRIER"
+            | "IN_MASK_CREATE"
             | "IPPROTO_BEETPH"
+            | "IPPROTO_ETHERNET"
             | "IPPROTO_MPLS"
+            | "IPPROTO_MPTCP"
             | "IPV6_HDRINCL"
             | "IPV6_MULTICAST_ALL"
             | "IPV6_PMTUDISC_INTERFACE"
             | "IPV6_PMTUDISC_OMIT"
             | "IPV6_ROUTER_ALERT_ISOLATE"
+            | "MADV_DONTNEED_LOCKED"
+            | "MFD_EXEC"
+            | "MFD_NOEXEC_SEAL"
+            | "NF_NETDEV_EGRESS"
+            | "NFQA_PRIORITY"
+            | "NLM_F_BULK"
+            | "NT_PRFPREG"
+            | "PACKET_FANOUT_FLAG_IGNORE_OUTGOING"
             | "PACKET_MR_UNICAST"
+            | "PACKET_VNET_HDR_SZ"
+            | "POSIX_SPAWN_SETSID"
+            | "PR_GET_MDWE"
+            | "PR_MDWE_NO_INHERIT"
+            | "PR_MDWE_REFUSE_EXEC_GAIN"
+            | "PR_SCHED_CORE_SCOPE_PROCESS_GROUP"
+            | "PR_SCHED_CORE_SCOPE_THREAD_GROUP"
+            | "PR_SCHED_CORE_SCOPE_THREAD"
+            | "PR_SET_MDWE"
+            | "PR_SET_VMA_ANON_NAME"
+            | "PR_SET_VMA"
+            | "RTNLGRP_MCTP_IFADDR"
+            | "RTNLGRP_STATS"
+            | "RTNLGRP_TUNNEL"
             | "RUSAGE_THREAD"
+            | "SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV"
+            | "SEM_STAT_ANY"
             | "SHM_EXEC"
+            | "SI_DETHREAD"
+            | "SO_PASSPIDFD"
+            | "SO_PEERPIDFD"
+            | "SO_RCVMARK"
+            | "SO_RESERVE_MEM"
+            | "SO_TXREHASH"
+            | "SOF_TIMESTAMPING_OPT_ID_TCP"
+            | "TFD_TIMER_CANCEL_ON_SET"
+            | "TLS_CIPHER_ARIA_GCM_128_IV_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_128_KEY_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_128_REC_SEQ_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_128_SALT_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_128_TAG_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_128"
+            | "TLS_CIPHER_ARIA_GCM_256_IV_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_256_KEY_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_256_REC_SEQ_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_256_SALT_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_256_TAG_SIZE"
+            | "TLS_CIPHER_ARIA_GCM_256"
+            | "TLS_CIPHER_SM4_CCM_IV_SIZE"
+            | "TLS_CIPHER_SM4_CCM_KEY_SIZE"
+            | "TLS_CIPHER_SM4_CCM_REC_SEQ_SIZE"
+            | "TLS_CIPHER_SM4_CCM_SALT_SIZE"
+            | "TLS_CIPHER_SM4_CCM_TAG_SIZE"
+            | "TLS_CIPHER_SM4_CCM"
+            | "TLS_CIPHER_SM4_GCM_IV_SIZE"
+            | "TLS_CIPHER_SM4_GCM_KEY_SIZE"
+            | "TLS_CIPHER_SM4_GCM_REC_SEQ_SIZE"
+            | "TLS_CIPHER_SM4_GCM_SALT_SIZE"
+            | "TLS_CIPHER_SM4_GCM_TAG_SIZE"
+            | "TLS_CIPHER_SM4_GCM"
+            | "TLS_INFO_RX_NO_PAD"
+            | "TLS_INFO_ZC_RO_TX"
+            | "TLS_RX_EXPECT_NO_PAD"
+            | "TLS_TX_ZEROCOPY_RO"
+            | "TRAP_BRANCH"
+            | "TRAP_HWBKPT"
+            | "TRAP_UNK"
+            | "TUN_F_USO4"
+            | "TUN_F_USO6"
             | "UDP_GRO"
             | "UDP_SEGMENT"
                 if uclibc =>
@@ -4418,6 +4576,10 @@ fn test_linux(target: &str) {
             // value changed
             "NF_NETDEV_NUMHOOKS" if sparc64 => true,
 
+            // Canonical uclibc latest from toolchains.bootlin.com is based on kernel 5.15,
+            // so opt out of tests for constants which are different in later kernels.
+            "NF_NETDEV_NUMHOOKS" | "RLIM_NLIMITS" | "NFT_MSG_MAX" if uclibc => true,
+
             // kernel 6.9 minimum
             "RWF_NOAPPEND" => true,
 
@@ -4627,8 +4789,9 @@ fn test_linux(target: &str) {
             // Needs glibc 2.33 or later.
             "mallinfo2" => true,
 
-            // Not defined in uclibc as of 1.0.34
+            // Not defined in uclibc as of 1.0.45
             "gettid" if uclibc => true,
+            "getauxval" if uclibc => true,
 
             // There are two versions of basename(3) on Linux with glibc, see
             //
@@ -4760,7 +4923,7 @@ fn test_linux(target: &str) {
             // FIXME(linux): `max_phase_adj` requires >= 5.19 kernel headers
             // the rsv field shrunk when those fields got added, so is omitted too
             ("ptp_clock_caps", "adjust_phase" | "max_phase_adj" | "rsv")
-                if loongarch64 || sparc64 =>
+                if loongarch64 || sparc64 || uclibc =>
             {
                 true
             }
@@ -4777,7 +4940,7 @@ fn test_linux(target: &str) {
             ("bcm_msg_head", "frames") => true,
             // FAM
             ("af_alg_iv", "iv") => true,
-            ("file_handle", "f_handle") if musl => true,
+            ("file_handle", "f_handle") if musl || uclibc => true,
             // FIXME(ctest): ctest does not translate the rust code which computes the padding size
             ("pthread_cond_t", "__padding") if l4re => true,
             _ => false,
diff --git a/src/unix/linux_like/linux/uclibc/arm/mod.rs b/src/unix/linux_like/linux/uclibc/arm/mod.rs
@@ -2,15 +2,24 @@ use crate::off64_t;
 use crate::prelude::*;
 
 pub type wchar_t = c_uint;
-pub type time_t = c_long;
+
+cfg_if! {
+    // Set cfg(libc_unstable_uclibc_time64) in rustflags if your uclibc has 64-bit time
+    if #[cfg(linux_time_bits64)] {
+        pub type time_t = c_longlong;
+        pub type suseconds_t = c_longlong;
+    } else {
+        pub type time_t = c_long;
+        pub type suseconds_t = c_long;
+    }
+}
 
 pub type clock_t = c_long;
 pub type fsblkcnt_t = c_ulong;
 pub type fsfilcnt_t = c_ulong;
 pub type ino_t = c_ulong;
 pub type off_t = c_long;
 pub type pthread_t = c_ulong;
-pub type suseconds_t = c_long;
 
 pub type nlink_t = c_uint;
 pub type blksize_t = c_long;
diff --git a/src/unix/linux_like/linux/uclibc/mod.rs b/src/unix/linux_like/linux/uclibc/mod.rs
diff --git a/src/unix/linux_like/linux_l4re_shared.rs b/src/unix/linux_like/linux_l4re_shared.rs
diff --git a/src/unix/linux_like/mod.rs b/src/unix/linux_like/mod.rs

Original file line number	Diff line number	Diff line change
`@@ -123,6 +123,11 @@ fn main() {`
`123`	`123`	`}`
`124`	`124`	`}`
`125`	`125`
	`126`	`+ let uclibc_use_time64 = env_flag("CARGO_CFG_LIBC_UNSTABLE_UCLIBC_TIME64");`
	`127`	`+ if target_env == "uclibc" && uclibc_use_time64 {`
	`128`	`+ set_cfg("linux_time_bits64");`
	`129`	`+ }`
	`130`	`+`
`126`	`131`	`let linux_time_bits64 = env::var("RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64").is_ok();`
`127`	`132`	`println!("cargo:rerun-if-env-changed=RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64");`
`128`	`133`	`if linux_time_bits64 {`