[libc] add ioctl

libc/config/linux/aarch64/entrypoints.txt

@@ -245,6 +245,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     # https://github.com/llvm/llvm-project/issues/80060
     # libc.src.sys.epoll.epoll_pwait2
 
+    # sys/ioctl.h entrypoints
+    libc.src.sys.ioctl.ioctl
+
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
     libc.src.sys.mman.mincore

libc/config/linux/arm/entrypoints.txt

@@ -172,6 +172,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.free
     libc.src.stdlib.malloc
 
+    # sys/ioctl.h entrypoints
+    libc.src.sys.ioctl.ioctl
+
     # sys/mman.h entrypoints
     libc.src.sys.mman.mmap
     libc.src.sys.mman.munmap

libc/config/linux/riscv/entrypoints.txt

@@ -246,6 +246,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     # https://github.com/llvm/llvm-project/issues/80060
     # libc.src.sys.epoll.epoll_pwait2
 
+    # sys/ioctl.h entrypoints
+    libc.src.sys.ioctl.ioctl
+
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
     libc.src.sys.mman.mincore

libc/config/linux/x86_64/entrypoints.txt

@@ -246,6 +246,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     # https://github.com/llvm/llvm-project/issues/80060
     # libc.src.sys.epoll.epoll_pwait2
 
+    # sys/ioctl.h entrypoints
+    libc.src.sys.ioctl.ioctl
+
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
     libc.src.sys.mman.mincore

libc/src/sys/CMakeLists.txt

@@ -13,3 +13,4 @@ add_subdirectory(utsname)
 add_subdirectory(wait)
 add_subdirectory(prctl)
 add_subdirectory(uio)
+add_subdirectory(ioctl)

libc/src/sys/ioctl/CMakeLists.txt

@@ -0,0 +1,10 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+endif()
+
+add_entrypoint_object(
+  ioctl
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.ioctl
+)

libc/src/sys/ioctl/ioctl.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for ioctl ---------------------------*-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_SYS_IOCTL_IOCTL_H
+#define LLVM_LIBC_SRC_SYS_IOCTL_IOCTL_H
+
+#include "src/__support/macros/config.h"
+#include <sys/ioctl.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+int ioctl(int fd, unsigned long request, ...);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_IOCTL_IOCTL_H

libc/src/sys/ioctl/linux/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_entrypoint_object(
+  ioctl
+  SRCS
+    ioctl.cpp
+  HDRS
+    ../ioctl.h
+  DEPENDS
+    libc.include.sys_ioctl
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)

libc/src/sys/ioctl/linux/ioctl.cpp

@@ -0,0 +1,36 @@
+//===---------- Linux implementation of the ioctl function ----------------===//
+//
+// 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/sys/ioctl/ioctl.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+#include "src/errno/libc_errno.h"
+#include <stdarg.h>
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, ioctl, (int fd, unsigned long request, ...)) {
+  va_list vargs;
+  va_start(vargs, request);
+  void *data_pointer = va_arg(vargs, void *);
+  int ret =
+      LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, request, data_pointer);
+  va_end(vargs);
+
+  // Some ioctls can be expected to return positive values
+  if (ret >= 0)
+    return ret;
+
+  // If there is an error, errno is set and -1 is returned.
+  libc_errno = -ret;
+  return -1;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/termios/linux/tcdrain.cpp

@@ -13,19 +13,14 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(int, tcdrain, (int fd)) {
-  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TCSBRK, 1);
-  if (ret < 0) {
-    libc_errno = -ret;
-    return -1;
-  }
-  return 0;
+  return LIBC_NAMESPACE::ioctl(fd, TCSBRK, 1);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/termios/linux/tcflow.cpp

@@ -13,19 +13,14 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(int, tcflow, (int fd, int action)) {
-  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TCXONC, action);
-  if (ret < 0) {
-    libc_errno = -ret;
-    return -1;
-  }
-  return 0;
+  return LIBC_NAMESPACE::ioctl(fd, TCXONC, action);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/termios/linux/tcflush.cpp

@@ -13,20 +13,14 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(int, tcflush, (int fd, int queue_selector)) {
-  int ret =
-      LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TCFLSH, queue_selector);
-  if (ret < 0) {
-    libc_errno = -ret;
-    return -1;
-  }
-  return 0;
+  return LIBC_NAMESPACE::ioctl(fd, TCFLSH, queue_selector);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/termios/linux/tcgetattr.cpp

@@ -14,19 +14,18 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(int, tcgetattr, (int fd, struct termios *t)) {
   LIBC_NAMESPACE::kernel_termios kt;
-  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TCGETS, &kt);
-  if (ret < 0) {
-    libc_errno = -ret;
+  int ret = LIBC_NAMESPACE::ioctl(fd, TCGETS, &kt);
+  if (ret < 0)
     return -1;
-  }
+
   t->c_iflag = kt.c_iflag;
   t->c_oflag = kt.c_oflag;
   t->c_cflag = kt.c_cflag;

libc/src/termios/linux/tcgetsid.cpp

@@ -13,19 +13,18 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(pid_t, tcgetsid, (int fd)) {
   pid_t sid;
-  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TIOCGSID, &sid);
-  if (ret < 0) {
-    libc_errno = -ret;
+  int ret = LIBC_NAMESPACE::ioctl(fd, TIOCGSID, &sid);
+  if (ret < 0) 
     return -1;
-  }
+    
   return sid;
 }
 

libc/src/termios/linux/tcsendbreak.cpp

@@ -13,7 +13,7 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
@@ -23,12 +23,7 @@ LLVM_LIBC_FUNCTION(pid_t, tcsendbreak, (int fd, int /* unused duration */)) {
   // POSIX leaves the behavior for non-zero duration implementation dependent.
   // Which means that the behavior can be the same as it is when duration is
   // zero. So, we just pass zero to the syscall.
-  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TCSBRK, 0);
-  if (ret < 0) {
-    libc_errno = -ret;
-    return -1;
-  }
-  return 0;
+  return LIBC_NAMESPACE::ioctl(SYS_ioctl, fd, TCSBRK, 0);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/termios/linux/tcsetattr.cpp

@@ -14,7 +14,7 @@
 #include "src/__support/macros/config.h"
 #include "src/errno/libc_errno.h"
 
-#include <asm/ioctls.h> // Safe to include without the risk of name pollution.
+#include <asm/ioctls.h>  // Safe to include without the risk of name pollution.
 #include <sys/syscall.h> // For syscall numbers
 #include <termios.h>
 
@@ -52,12 +52,7 @@ LLVM_LIBC_FUNCTION(int, tcsetattr,
       kt.c_cc[i] = 0;
   }
 
-  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, cmd, &kt);
-  if (ret < 0) {
-    libc_errno = -ret;
-    return -1;
-  }
-  return 0;
+  return LIBC_NAMESPACE::ioctl(fd, cmd, &kt);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/unistd/linux/isatty.cpp

@@ -23,12 +23,10 @@ LLVM_LIBC_FUNCTION(int, isatty, (int fd)) {
   int line_d_val = INIT_VAL;
   // This gets the line dicipline of the terminal. When called on something that
   // isn't a terminal it doesn't change line_d_val and returns -1.
-  int result =
-      LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TIOCGETD, &line_d_val);
+  int result = LIBC_NAMESPACE::ioctl(fd, TIOCGETD, &line_d_val);
   if (result == 0)
     return 1;
 
-  libc_errno = -result;
   return 0;
 }
 

libc/test/src/sys/CMakeLists.txt

@@ -13,3 +13,4 @@ add_subdirectory(auxv)
 add_subdirectory(epoll)
 add_subdirectory(uio)
 add_subdirectory(time)
+add_subdirectory(ioctl)

libc/test/src/sys/ioctl/CMakeLists.txt

@@ -0,0 +1,3 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${LIBC_TARGET_OS})
+endif()

libc/test/src/sys/ioctl/linux/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_custom_target(libc_sys_ioctl_unittests)
+
+add_libc_unittest(
+  ioctl_test
+  SUITE
+    libc_sys_ioctl_unittests
+  SRCS
+    ioctl_test.cpp
+  DEPENDS
+    libc.include.sys_ioctl
+    libc.include.sys_filio
+    libc.src.sys.ioctl.ioctl
+    libc.src.errno.errno
+)

libc/test/src/sys/ioctl/linux/ioctl_test.cpp

@@ -0,0 +1,34 @@
+//===-- Unittests for ioctl -----------------------------------------------===//
+//
+// 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/sys/ioctl/ioctl.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include <sys/filio.h>
+#include <sys/ioctl.h>
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+
+TEST(LlvmLibcSysIoctlTest, StdinFIONREAD) {
+  LIBC_NAMESPACE::libc_errno = 0;
+
+  // FIONREAD reports the number of readable bytes for fd
+  int bytes;
+  int ret = LIBC_NAMESPACE::ioctl(0, FIONREAD, &bytes);
+  ASSERT_ERRNO_SUCCESS();
+}
+
+TEST(LlvmLibcSysIoctlTest, InvalidCommandENOTTY) {
+  LIBC_NAMESPACE::libc_errno = 0;
+
+  // 0xDEADBEEF is just a random nonexistent command;
+  // calling this should always fail with ENOTTY
+  int ret = LIBC_NAMESPACE::ioctl(3, 0xDEADBEEF, NULL);
+  ASSERT_TRUE(ret == -1 && errno == ENOTTY);
+}