[libc-commits] [libc] [libc][SysMMan] implement mincore (PR #73704)
Schrodinger ZHU Yifan via libc-commits
libc-commits at lists.llvm.org
Tue Nov 28 16:28:53 PST 2023
https://github.com/SchrodingerZhu updated https://github.com/llvm/llvm-project/pull/73704
>From f853c24217c21bab4d04d80cb17cda525e6be7d4 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <yifanzhu at rochester.edu>
Date: Tue, 28 Nov 2023 16:57:01 -0500
Subject: [PATCH 1/2] [libc][SysMMan] implement mincore
---
libc/config/linux/aarch64/entrypoints.txt | 1 +
libc/config/linux/riscv/entrypoints.txt | 1 +
libc/config/linux/x86_64/entrypoints.txt | 1 +
libc/spec/linux.td | 15 ++-
libc/spec/spec.td | 2 +
libc/src/sys/mman/CMakeLists.txt | 7 ++
libc/src/sys/mman/linux/CMakeLists.txt | 13 +++
libc/src/sys/mman/linux/mincore.cpp | 28 ++++++
libc/src/sys/mman/mincore.h | 20 ++++
libc/test/src/sys/mman/linux/CMakeLists.txt | 16 ++++
libc/test/src/sys/mman/linux/mincore_test.cpp | 96 +++++++++++++++++++
11 files changed, 199 insertions(+), 1 deletion(-)
create mode 100644 libc/src/sys/mman/linux/mincore.cpp
create mode 100644 libc/src/sys/mman/mincore.h
create mode 100644 libc/test/src/sys/mman/linux/mincore_test.cpp
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 284feb7b99096ec..941c1e04ea20b6f 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -136,6 +136,7 @@ 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 a5f0c91e32d0810..5849dd68cc03263 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -142,6 +142,7 @@ 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 63aa7473115a08e..dbac381a64e87be 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -142,6 +142,7 @@ 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 ba5f99c12ecd116..eab0a987b920cd9 100644
--- a/libc/spec/linux.td
+++ b/libc/spec/linux.td
@@ -76,7 +76,20 @@ def Linux : StandardSpec<"Linux"> {
HeaderSpec SysMMan = HeaderSpec<
"sys/mman.h",
- [Macro<"MAP_ANONYMOUS">]
+ [Macro<"MAP_ANONYMOUS">],
+ [], // Types
+ [], // Enumerations
+ [
+ FunctionSpec<
+ "mincore",
+ RetValSpec<IntType>,
+ [
+ ArgSpec<VoidPtr>,
+ ArgSpec<SizeTType>,
+ ArgSpec<UnsignedCharPtr>,
+ ]
+ >,
+ ] // Functions
>;
diff --git a/libc/spec/spec.td b/libc/spec/spec.td
index b0d5511a4f087ee..3df3fc30f5e2b58 100644
--- a/libc/spec/spec.td
+++ b/libc/spec/spec.td
@@ -49,6 +49,7 @@ 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">;
@@ -109,6 +110,7 @@ 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 e336bfd5d6dbc6e..2d17429a26b457b 100644
--- a/libc/src/sys/mman/CMakeLists.txt
+++ b/libc/src/sys/mman/CMakeLists.txt
@@ -36,3 +36,10 @@ 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 163e7dead8887ab..ce0cda7f2227708 100644
--- a/libc/src/sys/mman/linux/CMakeLists.txt
+++ b/libc/src/sys/mman/linux/CMakeLists.txt
@@ -61,3 +61,16 @@ 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
new file mode 100644
index 000000000000000..8220c69ef2cb77c
--- /dev/null
+++ b/libc/src/sys/mman/linux/mincore.cpp
@@ -0,0 +1,28 @@
+//===---------- 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
new file mode 100644
index 000000000000000..403afaeb6af970c
--- /dev/null
+++ b/libc/src/sys/mman/mincore.h
@@ -0,0 +1,20 @@
+//===-- 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 66743be175fed1d..5402ae030b345c6 100644
--- a/libc/test/src/sys/mman/linux/CMakeLists.txt
+++ b/libc/test/src/sys/mman/linux/CMakeLists.txt
@@ -62,3 +62,19 @@ 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.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
new file mode 100644
index 000000000000000..0291b419f03c627
--- /dev/null
+++ b/libc/test/src/sys/mman/linux/mincore_test.cpp
@@ -0,0 +1,96 @@
+//===-- 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 "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/LibcTest.h"
+#include "test/UnitTest/Test.h"
+
+#include <linux/param.h> // For EXEC_PAGESIZE
+#include <sys/mman.h>
+
+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));
+}
+
+TEST(LlvmLibcMincoreTest, InvalidVec) {
+ void *addr = LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+ EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
+ libc_errno = 0;
+ int res = LIBC_NAMESPACE::mincore(addr, 1, nullptr);
+ EXPECT_THAT(res, Fails(EFAULT, -1));
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
+}
+
+TEST(LlvmLibcMincoreTest, UnalignedAddr) {
+ void *addr = LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+ EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
+ libc_errno = 0;
+ int res = LIBC_NAMESPACE::mincore(static_cast<char *>(addr) + 1, 1, nullptr);
+ EXPECT_THAT(res, Fails(EINVAL, -1));
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
+}
+
+TEST(LlvmLibcMincoreTest, NoError) {
+ void *addr = LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+ EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
+ unsigned char vec;
+ libc_errno = 0;
+ int res = LIBC_NAMESPACE::mincore(static_cast<char *>(addr), 1, &vec);
+ EXPECT_THAT(res, Succeeds());
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
+}
+
+TEST(LlvmLibcMincoreTest, PageOut) {
+ unsigned char vec;
+ void *addr =
+ LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+ EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
+
+ // touch the page
+ {
+ static_cast<char *>(addr)[0] = 0;
+ libc_errno = 0;
+ int res = LIBC_NAMESPACE::mincore(static_cast<char *>(addr), 1, &vec);
+ EXPECT_EQ(vec, static_cast<unsigned char>(1));
+ EXPECT_THAT(res, Succeeds());
+ }
+
+ // page out the memory
+ {
+ libc_errno = 0;
+ EXPECT_THAT(LIBC_NAMESPACE::madvise(addr, EXEC_PAGESIZE, MADV_DONTNEED),
+ Succeeds());
+
+ libc_errno = 0;
+ int res =
+ LIBC_NAMESPACE::mincore(static_cast<char *>(addr), EXEC_PAGESIZE, &vec);
+ EXPECT_EQ(vec, static_cast<unsigned char>(0));
+ EXPECT_THAT(res, Succeeds());
+ }
+
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
+}
>From 63e77fbf9bd2cfb09a7e0de7d85af6e5cfe95b4a Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <yifanzhu at rochester.edu>
Date: Tue, 28 Nov 2023 19:28:37 -0500
Subject: [PATCH 2/2] address code reviews
---
libc/test/src/sys/mman/linux/mincore_test.cpp | 33 +++++++++++++++----
1 file changed, 26 insertions(+), 7 deletions(-)
diff --git a/libc/test/src/sys/mman/linux/mincore_test.cpp b/libc/test/src/sys/mman/linux/mincore_test.cpp
index 0291b419f03c627..7c8ca3b4ffa4ccc 100644
--- a/libc/test/src/sys/mman/linux/mincore_test.cpp
+++ b/libc/test/src/sys/mman/linux/mincore_test.cpp
@@ -29,14 +29,22 @@ TEST(LlvmLibcMincoreTest, UnMappedMemory) {
}
TEST(LlvmLibcMincoreTest, InvalidVec) {
- void *addr = LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ,
+ void *addr = LIBC_NAMESPACE::mmap(nullptr, 4 * EXEC_PAGESIZE, PROT_READ,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
EXPECT_NE(addr, MAP_FAILED);
EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
libc_errno = 0;
int res = LIBC_NAMESPACE::mincore(addr, 1, nullptr);
EXPECT_THAT(res, Fails(EFAULT, -1));
+ void *area =
+ LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ EXPECT_NE(area, MAP_FAILED);
+ unsigned char *ptr = static_cast<unsigned char *>(area) + EXEC_PAGESIZE - 3;
+ res = LIBC_NAMESPACE::mincore(addr, 4 * EXEC_PAGESIZE, ptr);
+ EXPECT_THAT(res, Fails(EFAULT, -1));
EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(area, 2), Succeeds());
}
TEST(LlvmLibcMincoreTest, UnalignedAddr) {
@@ -57,11 +65,23 @@ TEST(LlvmLibcMincoreTest, NoError) {
EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
unsigned char vec;
libc_errno = 0;
- int res = LIBC_NAMESPACE::mincore(static_cast<char *>(addr), 1, &vec);
+ int res = LIBC_NAMESPACE::mincore(addr, 1, &vec);
EXPECT_THAT(res, Succeeds());
EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
}
+TEST(LlvmLibcMincoreTest, NegativeLength) {
+ void *addr = LIBC_NAMESPACE::mmap(nullptr, EXEC_PAGESIZE, PROT_READ,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+ EXPECT_EQ(reinterpret_cast<unsigned long>(addr) % EXEC_PAGESIZE, 0ul);
+ unsigned char vec;
+ libc_errno = 0;
+ int res = LIBC_NAMESPACE::mincore(addr, -1, &vec);
+ EXPECT_THAT(res, Fails(ENOMEM, -1));
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, EXEC_PAGESIZE), Succeeds());
+}
+
TEST(LlvmLibcMincoreTest, PageOut) {
unsigned char vec;
void *addr =
@@ -74,8 +94,8 @@ TEST(LlvmLibcMincoreTest, PageOut) {
{
static_cast<char *>(addr)[0] = 0;
libc_errno = 0;
- int res = LIBC_NAMESPACE::mincore(static_cast<char *>(addr), 1, &vec);
- EXPECT_EQ(vec, static_cast<unsigned char>(1));
+ int res = LIBC_NAMESPACE::mincore(addr, 1, &vec);
+ EXPECT_EQ(vec & 1u, 1u);
EXPECT_THAT(res, Succeeds());
}
@@ -86,9 +106,8 @@ TEST(LlvmLibcMincoreTest, PageOut) {
Succeeds());
libc_errno = 0;
- int res =
- LIBC_NAMESPACE::mincore(static_cast<char *>(addr), EXEC_PAGESIZE, &vec);
- EXPECT_EQ(vec, static_cast<unsigned char>(0));
+ int res = LIBC_NAMESPACE::mincore(addr, EXEC_PAGESIZE, &vec);
+ EXPECT_EQ(vec & 1u, 0u);
EXPECT_THAT(res, Succeeds());
}
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