[libc-commits] [libc] [libc] [unistd] implement pipe2 syscall wrapper (PR #114474)

via libc-commits libc-commits at lists.llvm.org
Thu Oct 31 16:52:37 PDT 2024


https://github.com/duncpro updated https://github.com/llvm/llvm-project/pull/114474

>From b1e2ea64182ddab6775ab6cfe5168c98c92c1a57 Mon Sep 17 00:00:00 2001
From: Duncan <duncpro at icloud.com>
Date: Thu, 31 Oct 2024 18:33:05 -0400
Subject: [PATCH 1/2] [libc] [unistd] implement pipe2 syscall wrapper

---
 libc/config/linux/aarch64/entrypoints.txt |  1 +
 libc/config/linux/riscv/entrypoints.txt   |  1 +
 libc/config/linux/x86_64/entrypoints.txt  |  1 +
 libc/newhdrgen/yaml/unistd.yaml           |  7 ++++++
 libc/spec/linux.td                        | 18 ++++++++++++++
 libc/src/unistd/CMakeLists.txt            |  7 ++++++
 libc/src/unistd/linux/CMakeLists.txt      | 13 ++++++++++
 libc/src/unistd/linux/pipe2.cpp           | 30 +++++++++++++++++++++++
 libc/src/unistd/pipe2.h                   | 20 +++++++++++++++
 libc/test/src/unistd/CMakeLists.txt       | 14 +++++++++++
 libc/test/src/unistd/pipe2_test.cpp       | 30 +++++++++++++++++++++++
 11 files changed, 142 insertions(+)
 create mode 100644 libc/src/unistd/linux/pipe2.cpp
 create mode 100644 libc/src/unistd/pipe2.h
 create mode 100644 libc/test/src/unistd/pipe2_test.cpp

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index b3f94a581c8ad9..69275f39355592 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -330,6 +330,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.lseek
     libc.src.unistd.pathconf
     libc.src.unistd.pipe
+    libc.src.unistd.pipe2
     libc.src.unistd.pread
     libc.src.unistd.pwrite
     libc.src.unistd.read
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 5c09edf7cfb266..6e098abe630827 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -329,6 +329,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.lseek
     libc.src.unistd.pathconf
     libc.src.unistd.pipe
+    libc.src.unistd.pipe2
     libc.src.unistd.pread
     libc.src.unistd.pwrite
     libc.src.unistd.read
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index a2fb97d04584d5..a20dd79c64b70a 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -329,6 +329,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.lseek
     libc.src.unistd.pathconf
     libc.src.unistd.pipe
+    libc.src.unistd.pipe2
     libc.src.unistd.pread
     libc.src.unistd.pwrite
     libc.src.unistd.read
diff --git a/libc/newhdrgen/yaml/unistd.yaml b/libc/newhdrgen/yaml/unistd.yaml
index 4d12abe96a2ec4..c6441c04ce3a3d 100644
--- a/libc/newhdrgen/yaml/unistd.yaml
+++ b/libc/newhdrgen/yaml/unistd.yaml
@@ -204,6 +204,13 @@ functions:
     return_type: int
     arguments:
       - type: int *
+  - name: pipe2
+    standards:
+      - Linux
+    return_type: int
+    arguments:
+      - type: int *
+      - type: int
   - name: pread
     standards:
       - POSIX
diff --git a/libc/spec/linux.td b/libc/spec/linux.td
index 4aaf18b0803f3d..7214f738f0ada8 100644
--- a/libc/spec/linux.td
+++ b/libc/spec/linux.td
@@ -287,6 +287,23 @@ def Linux : StandardSpec<"Linux"> {
       ]
   >;
 
+
+  HeaderSpec UniStd = HeaderSpec<
+    "unistd.h",
+    [], // Macros
+    [],
+    [], // Enumerations
+    [
+        FunctionSpec<
+          "pipe2",
+          RetValSpec<IntType>,
+          [ArgSpec<IntPtr>] //TODO: make this int[2]
+        >,
+    ],
+    []
+  >;
+  
+
   let Headers = [
     Errno,
     SysEpoll,
@@ -295,5 +312,6 @@ def Linux : StandardSpec<"Linux"> {
     SysRandom,
     SysTime,
     Signal,
+    UniStd,
   ];
 }
diff --git a/libc/src/unistd/CMakeLists.txt b/libc/src/unistd/CMakeLists.txt
index 64e07725010b31..1a0b2e3293d03c 100644
--- a/libc/src/unistd/CMakeLists.txt
+++ b/libc/src/unistd/CMakeLists.txt
@@ -182,6 +182,13 @@ add_entrypoint_object(
     .${LIBC_TARGET_OS}.pipe
 )
 
+add_entrypoint_object(
+  pipe2
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.pipe2
+)
+
 add_entrypoint_object(
   pread
   ALIAS
diff --git a/libc/src/unistd/linux/CMakeLists.txt b/libc/src/unistd/linux/CMakeLists.txt
index 472438ca72e49e..33fca036291dfb 100644
--- a/libc/src/unistd/linux/CMakeLists.txt
+++ b/libc/src/unistd/linux/CMakeLists.txt
@@ -330,6 +330,19 @@ add_entrypoint_object(
     libc.src.errno.errno
 )
 
+add_entrypoint_object(
+  pipe2
+  SRCS
+    pipe2.cpp
+  HDRS
+    ../pipe2.h
+  DEPENDS
+    libc.include.unistd
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)
+
 add_entrypoint_object(
   pread
   SRCS
diff --git a/libc/src/unistd/linux/pipe2.cpp b/libc/src/unistd/linux/pipe2.cpp
new file mode 100644
index 00000000000000..3820b0491cf279
--- /dev/null
+++ b/libc/src/unistd/linux/pipe2.cpp
@@ -0,0 +1,30 @@
+//===-- Linux implementation of pipe --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/unistd/pipe2.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/errno/libc_errno.h"
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, pipe2, (int pipefd[2], int flags)) {
+  int ret = LIBC_NAMESPACE::syscall_impl<int>(
+      SYS_pipe2, reinterpret_cast<long>(pipefd), flags);
+
+  if (ret < 0) {
+    libc_errno = -ret;
+    return -1;
+  }
+  return ret;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/unistd/pipe2.h b/libc/src/unistd/pipe2.h
new file mode 100644
index 00000000000000..7118f4aaf0171c
--- /dev/null
+++ b/libc/src/unistd/pipe2.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for pipe2 -------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_UNISTD_PIPE2_H
+#define LLVM_LIBC_SRC_UNISTD_PIPE2_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int pipe2(int pipefd[2], int flags);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_UNISTD_PIPE2_H
diff --git a/libc/test/src/unistd/CMakeLists.txt b/libc/test/src/unistd/CMakeLists.txt
index ce936cebad4260..e036e09cde702e 100644
--- a/libc/test/src/unistd/CMakeLists.txt
+++ b/libc/test/src/unistd/CMakeLists.txt
@@ -217,6 +217,20 @@ add_libc_unittest(
     libc.test.UnitTest.ErrnoSetterMatcher
 )
 
+add_libc_unittest(
+  pipe2_test
+  SUITE
+    libc_unistd_unittests
+  SRCS
+    pipe2_test.cpp
+  DEPENDS
+    libc.include.unistd
+    libc.src.errno.errno
+    libc.src.unistd.close
+    libc.src.unistd.pipe2
+    libc.test.UnitTest.ErrnoSetterMatcher
+)
+
 add_libc_unittest(
   rmdir_test
   SUITE
diff --git a/libc/test/src/unistd/pipe2_test.cpp b/libc/test/src/unistd/pipe2_test.cpp
new file mode 100644
index 00000000000000..110fbb8ed05d5d
--- /dev/null
+++ b/libc/test/src/unistd/pipe2_test.cpp
@@ -0,0 +1,30 @@
+//===-- Unittests for pipe2 -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "src/errno/libc_errno.h"
+#include "src/unistd/close.h"
+#include "src/unistd/pipe2.h"
+
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using namespace LIBC_NAMESPACE::testing::ErrnoSetterMatcher;
+
+TEST(LlvmLibcPipe2Test, SmokeTest) {
+  int pipefd[2];
+  ASSERT_THAT(LIBC_NAMESPACE::pipe2(pipefd, 0), Succeeds());
+  ASSERT_THAT(LIBC_NAMESPACE::close(pipefd[0]), Succeeds());
+  ASSERT_THAT(LIBC_NAMESPACE::close(pipefd[1]), Succeeds());
+}
+
+TEST(LlvmLibcPipe2ErrTest, SmokeTest) {
+  int pipefd[2];
+  ASSERT_THAT(LIBC_NAMESPACE::pipe2(pipefd, -1), Fails(EINVAL));
+  ASSERT_THAT(LIBC_NAMESPACE::pipe2(nullptr, 0), Fails(EFAULT));
+}
+
+// TODO: Functionality tests

>From f5b815a4c7d07bc7d62f20d34b787d40f001be66 Mon Sep 17 00:00:00 2001
From: Duncan <duncpro at icloud.com>
Date: Thu, 31 Oct 2024 19:52:29 -0400
Subject: [PATCH 2/2] unpoison file descriptor array

Co-authored-by: Michael Jones <michaelrj at google.com>
---
 libc/src/unistd/linux/pipe2.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libc/src/unistd/linux/pipe2.cpp b/libc/src/unistd/linux/pipe2.cpp
index 3820b0491cf279..15004838d86120 100644
--- a/libc/src/unistd/linux/pipe2.cpp
+++ b/libc/src/unistd/linux/pipe2.cpp
@@ -19,7 +19,7 @@ namespace LIBC_NAMESPACE_DECL {
 LLVM_LIBC_FUNCTION(int, pipe2, (int pipefd[2], int flags)) {
   int ret = LIBC_NAMESPACE::syscall_impl<int>(
       SYS_pipe2, reinterpret_cast<long>(pipefd), flags);
-
+  MSAN_UNPOISON(pipefd, sizeof(int) * 2);
   if (ret < 0) {
     libc_errno = -ret;
     return -1;



More information about the libc-commits mailing list