[libc] Revert #73704 and subsequent fixes #73984, #74026

[SchrodingerZhu]

The test cases of mincore require getting correct page size from OS. As sysconf is not functioning correctly, these patches are implemented in a somewhat confusing way. We revert such patches and will reintroduce mincore after we correct sysconf.

This reverts 54878b8, 985c0d1 and 418a3a4.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Schrodinger ZHU Yifan (SchrodingerZhu)

Changes

The test cases of mincore requires getting corrent page size from OS. As sysconf is not functioning correctly, these patches are implemented in a somewhat confusing way. We revert such patches and will reintroduce mincore after we correct sysconf.

This reverts 54878b8, 985c0d1 and 418a3a4.

---

Full diff: https://github.com/llvm/llvm-project/pull/74355.diff

11 Files Affected:

• (modified) libc/config/linux/aarch64/entrypoints.txt (-1)
• (modified) libc/config/linux/riscv/entrypoints.txt (-1)
• (modified) libc/config/linux/x86_64/entrypoints.txt (-1)
• (modified) libc/spec/linux.td (+1-14)
• (modified) libc/spec/spec.td (-2)
• (modified) libc/src/sys/mman/CMakeLists.txt (-7)
• (modified) libc/src/sys/mman/linux/CMakeLists.txt (-13)
• (removed) libc/src/sys/mman/linux/mincore.cpp (-28)
• (removed) libc/src/sys/mman/mincore.h (-20)
• (modified) libc/test/src/sys/mman/linux/CMakeLists.txt (-17)
• (removed) libc/test/src/sys/mman/linux/mincore_test.cpp (-123)

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index ba3a7c5579648..7a60c44570c4e 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -136,7 +136,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.mprotect
     libc.src.sys.mman.munmap
     libc.src.sys.mman.posix_madvise
-    libc.src.sys.mman.mincore
 
     # sys/random.h entrypoints
     libc.src.sys.random.getrandom
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 63c1f9227f91c..28687ef8e234e 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -142,7 +142,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.mprotect
     libc.src.sys.mman.munmap
     libc.src.sys.mman.posix_madvise
-    libc.src.sys.mman.mincore
 
     # sys/random.h entrypoints
     libc.src.sys.random.getrandom
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index eb5457678e990..43266e0e5b66e 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -142,7 +142,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.mprotect
     libc.src.sys.mman.munmap
     libc.src.sys.mman.posix_madvise
-    libc.src.sys.mman.mincore
 
     # sys/random.h entrypoints
     libc.src.sys.random.getrandom
diff --git a/libc/spec/linux.td b/libc/spec/linux.td
index eab0a987b920c..ba5f99c12ecd1 100644
--- a/libc/spec/linux.td
+++ b/libc/spec/linux.td
@@ -76,20 +76,7 @@ def Linux : StandardSpec<"Linux"> {
 
   HeaderSpec SysMMan = HeaderSpec<
       "sys/mman.h",
-      [Macro<"MAP_ANONYMOUS">],
-      [], // Types
-      [], // Enumerations
-      [
-        FunctionSpec<
-            "mincore",
-            RetValSpec<IntType>,
-            [
-              ArgSpec<VoidPtr>,
-              ArgSpec<SizeTType>,
-              ArgSpec<UnsignedCharPtr>,
-            ]
-        >,
-      ]  // Functions
+      [Macro<"MAP_ANONYMOUS">]
   >;
 
 
diff --git a/libc/spec/spec.td b/libc/spec/spec.td
index 818cfaee6b61c..9b689b5eb502a 100644
--- a/libc/spec/spec.td
+++ b/libc/spec/spec.td
@@ -49,7 +49,6 @@ def FloatType : NamedType<"float">;
 def DoubleType : NamedType<"double">;
 def LongDoubleType : NamedType<"long double">;
 def CharType : NamedType<"char">;
-def UnsignedCharType : NamedType<"unsigned char">;
 
 // TODO: Add compatibility layer to use C23 type _Float128 if possible.
 def Float128Type : NamedType<"__float128">;
@@ -110,7 +109,6 @@ def IntPtr : PtrType<IntType>;
 def RestrictedIntPtr : RestrictedPtrType<IntType>;
 def FloatPtr : PtrType<FloatType>;
 def DoublePtr : PtrType<DoubleType>;
-def UnsignedCharPtr : PtrType<UnsignedCharType>;
 
 def SigHandlerT : NamedType<"__sighandler_t">;
 
diff --git a/libc/src/sys/mman/CMakeLists.txt b/libc/src/sys/mman/CMakeLists.txt
index 2d17429a26b45..e336bfd5d6dbc 100644
--- a/libc/src/sys/mman/CMakeLists.txt
+++ b/libc/src/sys/mman/CMakeLists.txt
@@ -36,10 +36,3 @@ add_entrypoint_object(
   DEPENDS
     .${LIBC_TARGET_OS}.posix_madvise
 )
-
-add_entrypoint_object(
-  mincore
-  ALIAS
-  DEPENDS
-    .${LIBC_TARGET_OS}.mincore
-)
diff --git a/libc/src/sys/mman/linux/CMakeLists.txt b/libc/src/sys/mman/linux/CMakeLists.txt
index ce0cda7f22277..163e7dead8887 100644
--- a/libc/src/sys/mman/linux/CMakeLists.txt
+++ b/libc/src/sys/mman/linux/CMakeLists.txt
@@ -61,16 +61,3 @@ add_entrypoint_object(
     libc.include.sys_syscall
     libc.src.__support.OSUtil.osutil
 )
-
-add_entrypoint_object(
-  mincore
-  SRCS
-    mincore.cpp
-  HDRS
-    ../mincore.h
-  DEPENDS
-    libc.include.sys_mman
-    libc.include.sys_syscall
-    libc.src.__support.OSUtil.osutil
-    libc.src.errno.errno
-)
diff --git a/libc/src/sys/mman/linux/mincore.cpp b/libc/src/sys/mman/linux/mincore.cpp
deleted file mode 100644
index 8220c69ef2cb7..0000000000000
--- a/libc/src/sys/mman/linux/mincore.cpp
+++ /dev/null
@@ -1,28 +0,0 @@
-//===---------- Linux implementation of the mincore 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/mman/mincore.h"
-
-#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
-
-#include "src/errno/libc_errno.h"
-#include <sys/syscall.h> // For syscall numbers.
-
-namespace LIBC_NAMESPACE {
-
-LLVM_LIBC_FUNCTION(int, mincore, (void *addr, size_t len, unsigned char *vec)) {
-  long ret = syscall_impl(SYS_mincore, reinterpret_cast<long>(addr), len,
-                          reinterpret_cast<long>(vec));
-  if (ret < 0) {
-    libc_errno = static_cast<int>(-ret);
-    return -1;
-  }
-  return 0;
-}
-
-} // namespace LIBC_NAMESPACE
diff --git a/libc/src/sys/mman/mincore.h b/libc/src/sys/mman/mincore.h
deleted file mode 100644
index 403afaeb6af97..0000000000000
--- a/libc/src/sys/mman/mincore.h
+++ /dev/null
@@ -1,20 +0,0 @@
-//===-- Implementation header for mincore function --------------*- 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_MMAN_MINCORE_H
-#define LLVM_LIBC_SRC_SYS_MMAN_MINCORE_H
-
-#include <sys/mman.h> // For size_t
-
-namespace LIBC_NAMESPACE {
-
-int mincore(void *addr, size_t len, unsigned char *vec);
-
-} // namespace LIBC_NAMESPACE
-
-#endif // LLVM_LIBC_SRC_SYS_MMAN_MINCORE_H
diff --git a/libc/test/src/sys/mman/linux/CMakeLists.txt b/libc/test/src/sys/mman/linux/CMakeLists.txt
index c60377eb2cc1f..66743be175fed 100644
--- a/libc/test/src/sys/mman/linux/CMakeLists.txt
+++ b/libc/test/src/sys/mman/linux/CMakeLists.txt
@@ -62,20 +62,3 @@ add_libc_unittest(
     libc.src.sys.mman.posix_madvise
     libc.test.UnitTest.ErrnoSetterMatcher
 )
-
-add_libc_unittest(
-  mincore_test
-  SUITE
-    libc_sys_mman_unittests
-  SRCS
-    mincore_test.cpp
-  DEPENDS
-    libc.include.sys_mman
-    libc.src.errno.errno
-    libc.src.sys.mman.mmap
-    libc.src.sys.mman.munmap
-    libc.src.sys.mman.madvise
-    libc.src.sys.mman.mincore
-    libc.src.unistd.sysconf
-    libc.test.UnitTest.ErrnoSetterMatcher
-)
diff --git a/libc/test/src/sys/mman/linux/mincore_test.cpp b/libc/test/src/sys/mman/linux/mincore_test.cpp
deleted file mode 100644
index 1b0ed157483eb..0000000000000
--- a/libc/test/src/sys/mman/linux/mincore_test.cpp
+++ /dev/null
@@ -1,123 +0,0 @@
-//===-- Unittests for mincore ---------------------------------------------===//
-//
-// 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/mman/madvise.h"
-#include "src/sys/mman/mincore.h"
-#include "src/sys/mman/mmap.h"
-#include "src/sys/mman/munmap.h"
-#include "src/unistd/sysconf.h"
-#include "test/UnitTest/ErrnoSetterMatcher.h"
-#include "test/UnitTest/LibcTest.h"
-#include "test/UnitTest/Test.h"
-
-#include <sys/mman.h>
-#include <unistd.h> // For sysconf.
-
-using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
-using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
-
-TEST(LlvmLibcMincoreTest, UnMappedMemory) {
-  libc_errno = 0;
-  unsigned char vec;
-  int res = LIBC_NAMESPACE::mincore(nullptr, 1, &vec);
-  EXPECT_THAT(res, Fails(ENOMEM, -1));
-}
-
-// It is always possible to find an aligned boundary if we allocate page sized
-// memory.
-static char *aligned_addr(void *addr, size_t alignment) {
-  char *byte_addr = static_cast<char *>(addr);
-  uintptr_t addr_val = reinterpret_cast<uintptr_t>(addr);
-  uintptr_t offset =
-      addr_val % alignment == 0 ? 0 : alignment - (addr_val % alignment);
-  return byte_addr + offset;
-}
-
-TEST(LlvmLibcMincoreTest, InvalidVec) {
-  size_t page_size = static_cast<size_t>(LIBC_NAMESPACE::sysconf(_SC_PAGESIZE));
-  void *addr = LIBC_NAMESPACE::mmap(nullptr, page_size, PROT_READ,
-                                    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  EXPECT_NE(addr, MAP_FAILED);
-  char *aligned = aligned_addr(addr, page_size);
-  int res = LIBC_NAMESPACE::mincore(aligned, 1, nullptr);
-  EXPECT_THAT(res, Fails(EFAULT, -1));
-  EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, page_size), Succeeds());
-}
-
-TEST(LlvmLibcMincoreTest, UnalignedAddr) {
-  size_t page_size = static_cast<size_t>(LIBC_NAMESPACE::sysconf(_SC_PAGESIZE));
-  void *addr = LIBC_NAMESPACE::mmap(nullptr, page_size, PROT_READ,
-                                    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  EXPECT_NE(addr, MAP_FAILED);
-  char *aligned = aligned_addr(addr, page_size);
-  libc_errno = 0;
-  int res = LIBC_NAMESPACE::mincore(aligned + 1, 1, nullptr);
-  EXPECT_THAT(res, Fails(EINVAL, -1));
-  EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, page_size), Succeeds());
-}
-
-TEST(LlvmLibcMincoreTest, NoError) {
-  size_t page_size = static_cast<size_t>(LIBC_NAMESPACE::sysconf(_SC_PAGESIZE));
-  void *addr = LIBC_NAMESPACE::mmap(nullptr, page_size, PROT_READ,
-                                    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  EXPECT_NE(addr, MAP_FAILED);
-  char *aligned = aligned_addr(addr, page_size);
-  unsigned char vec;
-  libc_errno = 0;
-  int res = LIBC_NAMESPACE::mincore(aligned, 1, &vec);
-  EXPECT_THAT(res, Succeeds());
-  EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, page_size), Succeeds());
-}
-
-TEST(LlvmLibcMincoreTest, NegativeLength) {
-  size_t page_size = static_cast<size_t>(LIBC_NAMESPACE::sysconf(_SC_PAGESIZE));
-  void *addr = LIBC_NAMESPACE::mmap(nullptr, page_size, PROT_READ,
-                                    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  EXPECT_NE(addr, MAP_FAILED);
-  char *aligned = aligned_addr(addr, page_size);
-  unsigned char vec;
-  libc_errno = 0;
-  int res = LIBC_NAMESPACE::mincore(aligned, -1, &vec);
-  EXPECT_THAT(res, Fails(ENOMEM, -1));
-  EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, page_size), Succeeds());
-}
-
-TEST(LlvmLibcMincoreTest, PageOut) {
-  unsigned char vec;
-  size_t page_size = static_cast<size_t>(LIBC_NAMESPACE::sysconf(_SC_PAGESIZE));
-  // allocate 2 pages since we need to page out page_size bytes
-  void *addr =
-      LIBC_NAMESPACE::mmap(nullptr, 2 * page_size, PROT_READ | PROT_WRITE,
-                           MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  EXPECT_NE(addr, MAP_FAILED);
-  char *aligned = aligned_addr(addr, page_size);
-
-  // touch the page
-  {
-    aligned[0] = 0;
-    libc_errno = 0;
-    int res = LIBC_NAMESPACE::mincore(aligned, 1, &vec);
-    EXPECT_EQ(vec & 1u, 1u);
-    EXPECT_THAT(res, Succeeds());
-  }
-
-  // page out the memory
-  {
-    libc_errno = 0;
-    EXPECT_THAT(LIBC_NAMESPACE::madvise(aligned, page_size, MADV_DONTNEED),
-                Succeeds());
-
-    libc_errno = 0;
-    int res = LIBC_NAMESPACE::mincore(aligned, 1, &vec);
-    EXPECT_EQ(vec & 1u, 0u);
-    EXPECT_THAT(res, Succeeds());
-  }
-
-  EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, 2 * page_size), Succeeds());
-}

[nickdesaulniers]

That's ok, I look forward to getting this relanded (with the proper infrastructure in place landed first). Please use distinct PRs for each added entrypoint.