[libc-commits] [libc] ec62bf2 - [libc] Move the implementation of mmap and munmap into a linux specific area.
Siva Chandra Reddy via libc-commits
libc-commits at lists.llvm.org
Fri Jan 24 15:43:06 PST 2020
Author: Siva Chandra Reddy
Date: 2020-01-24T15:42:28-08:00
New Revision: ec62bf2fd3284c9a525011b191c4960fce01dca7
URL: https://github.com/llvm/llvm-project/commit/ec62bf2fd3284c9a525011b191c4960fce01dca7
DIFF: https://github.com/llvm/llvm-project/commit/ec62bf2fd3284c9a525011b191c4960fce01dca7.diff
LOG: [libc] Move the implementation of mmap and munmap into a linux specific area.
This allows us to get rid of the PAGE_SIZE macro and use EXEC_PAGESIZE
from linux/param.h.
Few other points about this change:
1. The linux syscall functions have been moved into a linux specific area
instead of src/unistd/syscall.h. The Linux syscall function from unistd.h
is a public vararg function. What we have currently are linux speciif internal
overloaded C++ functions. So, moving them to a Linux only area is more
meaningful.
2. The implementations of mmap and munmap are now in a 'linux' directory
within src/sys/mman. The idea here is that platform specific
implementations will live in a platform specific subdirectories like these.
Infrastructure common to a platform will live in the platform's config
directory. For example, the linux syscall implementations live in
config/linux.
Reviewers: abrachet
Tags: #libc-project
Differential Revision: https://reviews.llvm.org/D73302
Added:
libc/config/linux/syscall.h.def
libc/src/sys/mman/linux/CMakeLists.txt
libc/src/sys/mman/linux/mmap.cpp
libc/src/sys/mman/linux/munmap.cpp
libc/test/src/sys/mman/linux/CMakeLists.txt
libc/test/src/sys/mman/linux/mmap_test.cpp
Modified:
libc/config/linux/CMakeLists.txt
libc/config/linux/platfrom_defs.h.inc
libc/include/CMakeLists.txt
libc/src/CMakeLists.txt
libc/src/sys/mman/CMakeLists.txt
libc/test/config/linux/x86_64/CMakeLists.txt
libc/test/config/linux/x86_64/syscall_test.cpp
libc/test/src/sys/mman/CMakeLists.txt
Removed:
libc/src/sys/mman/mmap.cpp
libc/src/sys/mman/munmap.cpp
libc/src/unistd/CMakeLists.txt
libc/src/unistd/syscall.h.def
libc/test/src/sys/mman/mmap_test.cpp
################################################################################
diff --git a/libc/config/linux/CMakeLists.txt b/libc/config/linux/CMakeLists.txt
index 7e2608e595f5..86b178abb0de 100644
--- a/libc/config/linux/CMakeLists.txt
+++ b/libc/config/linux/CMakeLists.txt
@@ -1 +1,11 @@
+add_gen_header(
+ linux_syscall_h
+ DEF_FILE syscall.h.def
+ GEN_HDR syscall.h
+ PARAMS
+ inline_syscalls=${LIBC_TARGET_MACHINE}/syscall.h.inc
+ DATA_FILES
+ ${LIBC_TARGET_MACHINE}/syscall.h.inc
+)
+
add_subdirectory(x86_64)
diff --git a/libc/config/linux/platfrom_defs.h.inc b/libc/config/linux/platfrom_defs.h.inc
index 19bf3f7593c1..495d07c80cf2 100644
--- a/libc/config/linux/platfrom_defs.h.inc
+++ b/libc/config/linux/platfrom_defs.h.inc
@@ -11,9 +11,3 @@
#define ENTRYPOINT_SECTION_ATTRIBUTE(name) \
__attribute__((section(".llvm.libc.entrypoint."#name)))
#define LLVM_LIBC_ENTRYPOINT(name) ENTRYPOINT_SECTION_ATTRIBUTE(name) name
-
-// TODO: Get rid of the PAGE_SIZE macro. It is present only as an interim
-// measure until we can move the implementations of mmap and munmap to under
-// the config/linux directory. After that, the implementations can use
-// EXEC_PAGESIZE until page size can be read from the aux vector.
-#define PAGE_SIZE 4096
diff --git a/libc/src/unistd/syscall.h.def b/libc/config/linux/syscall.h.def
similarity index 100%
rename from libc/src/unistd/syscall.h.def
rename to libc/config/linux/syscall.h.def
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index 7773be6227a3..8558d7586b57 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -56,6 +56,7 @@ add_gen_header(
GEN_HDR sys/mman.h
DEPENDS
libc_posix_types_h
+ llvm_libc_common_h
)
add_gen_header(
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
index 28084cd9a9be..b416e83934d6 100644
--- a/libc/src/CMakeLists.txt
+++ b/libc/src/CMakeLists.txt
@@ -3,6 +3,5 @@ add_subdirectory(math)
add_subdirectory(string)
# TODO: Add this target conditional to the target OS.
add_subdirectory(sys)
-add_subdirectory(unistd)
add_subdirectory(__support)
diff --git a/libc/src/sys/mman/CMakeLists.txt b/libc/src/sys/mman/CMakeLists.txt
index 9b8cc66299a6..b4bbe81c92ff 100644
--- a/libc/src/sys/mman/CMakeLists.txt
+++ b/libc/src/sys/mman/CMakeLists.txt
@@ -1,27 +1,3 @@
-#TODO: The sources and target listed here should ideally live in config/linux.
-
-add_entrypoint_object(
- mmap
- SRCS
- mmap.cpp
- HDRS
- mmap.h
- DEPENDS
- sys_mman_h
- sys_syscall_h
- syscall_impl_h
- __errno_location
-)
-
-add_entrypoint_object(
- munmap
- SRCS
- munmap.cpp
- HDRS
- munmap.h
- DEPENDS
- sys_mman_h
- sys_syscall_h
- syscall_impl_h
- __errno_location
-)
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+ add_subdirectory(${LIBC_TARGET_OS})
+endif()
diff --git a/libc/src/sys/mman/linux/CMakeLists.txt b/libc/src/sys/mman/linux/CMakeLists.txt
new file mode 100644
index 000000000000..527da6471900
--- /dev/null
+++ b/libc/src/sys/mman/linux/CMakeLists.txt
@@ -0,0 +1,25 @@
+add_entrypoint_object(
+ mmap
+ SRCS
+ mmap.cpp
+ HDRS
+ ../mmap.h
+ DEPENDS
+ sys_mman_h
+ sys_syscall_h
+ linux_syscall_h
+ __errno_location
+)
+
+add_entrypoint_object(
+ munmap
+ SRCS
+ munmap.cpp
+ HDRS
+ ../munmap.h
+ DEPENDS
+ sys_mman_h
+ sys_syscall_h
+ linux_syscall_h
+ __errno_location
+)
diff --git a/libc/src/sys/mman/mmap.cpp b/libc/src/sys/mman/linux/mmap.cpp
similarity index 79%
rename from libc/src/sys/mman/mmap.cpp
rename to libc/src/sys/mman/linux/mmap.cpp
index 10ae0c70c98c..616cd98561a5 100644
--- a/libc/src/sys/mman/mmap.cpp
+++ b/libc/src/sys/mman/linux/mmap.cpp
@@ -1,4 +1,4 @@
-//===-------------- Implementation of the POSIX mmap function -------------===//
+//===---------- Linux implementation of the POSIX mmap function -----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -7,10 +7,13 @@
//===----------------------------------------------------------------------===//
#include "src/sys/mman/mmap.h"
-#include "include/sys/syscall.h" // For syscall numbers.
+
+#include "config/linux/syscall.h" // For internal syscall function.
+#include "include/sys/syscall.h" // For syscall numbers.
#include "src/__support/common.h"
#include "src/errno/llvmlibc_errno.h"
-#include "src/unistd/syscall.h" // For internal syscall function.
+
+#include <linux/param.h> // For EXEC_PAGESIZE.
namespace __llvm_libc {
@@ -22,8 +25,12 @@ void *LLVM_LIBC_ENTRYPOINT(mmap)(void *addr, size_t size, int prot, int flags,
// done in this function as modern linux versions do it in the syscall.
// TODO: Perform argument validation not done by the linux syscall.
+ // EXEC_PAGESIZE is used for the page size. While this is OK for x86_64, it
+ // might not be correct in general.
+ // TODO: Use pagesize read from the ELF aux vector instead of EXEC_PAGESIZE.
+
#ifdef SYS_mmap2
- offset /= PAGE_SIZE;
+ offset /= EXEC_PAGESIZE;
long syscall_number = SYS_mmap2;
#elif SYS_mmap
long syscall_number = SYS_mmap;
@@ -44,7 +51,7 @@ void *LLVM_LIBC_ENTRYPOINT(mmap)(void *addr, size_t size, int prot, int flags,
// However, since a valid return address cannot be within the last page, a
// return value corresponding to a location in the last page is an error
// value.
- if (ret_val < 0 && ret_val > -PAGE_SIZE) {
+ if (ret_val < 0 && ret_val > -EXEC_PAGESIZE) {
llvmlibc_errno = -ret_val;
return MAP_FAILED;
}
diff --git a/libc/src/sys/mman/munmap.cpp b/libc/src/sys/mman/linux/munmap.cpp
similarity index 81%
rename from libc/src/sys/mman/munmap.cpp
rename to libc/src/sys/mman/linux/munmap.cpp
index d11f53a418c0..1f112f8f1281 100644
--- a/libc/src/sys/mman/munmap.cpp
+++ b/libc/src/sys/mman/linux/munmap.cpp
@@ -1,4 +1,4 @@
-//===------------- Implementation of the POSIX munmap function ------------===//
+//===---------- Linux implementation of the POSIX munmap function ---------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -7,10 +7,11 @@
//===----------------------------------------------------------------------===//
#include "src/sys/mman/munmap.h"
-#include "include/sys/syscall.h" // For syscall numbers.
+
+#include "config/linux/syscall.h" // For internal syscall function.
+#include "include/sys/syscall.h" // For syscall numbers.
#include "src/__support/common.h"
#include "src/errno/llvmlibc_errno.h"
-#include "src/unistd/syscall.h" // For internal syscall function.
namespace __llvm_libc {
diff --git a/libc/src/unistd/CMakeLists.txt b/libc/src/unistd/CMakeLists.txt
deleted file mode 100644
index ed23b704dfe7..000000000000
--- a/libc/src/unistd/CMakeLists.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-add_gen_header(
- syscall_impl_h
- DEF_FILE syscall.h.def
- GEN_HDR syscall.h
- PARAMS
- inline_syscalls=../../config/${LIBC_TARGET_OS}/${LIBC_TARGET_MACHINE}/syscall.h.inc
- DATA_FILES
- ../../config/${LIBC_TARGET_OS}/${LIBC_TARGET_MACHINE}/syscall.h.inc
-)
diff --git a/libc/test/config/linux/x86_64/CMakeLists.txt b/libc/test/config/linux/x86_64/CMakeLists.txt
index 9f9d21251c6f..23f82b27c9bd 100644
--- a/libc/test/config/linux/x86_64/CMakeLists.txt
+++ b/libc/test/config/linux/x86_64/CMakeLists.txt
@@ -3,6 +3,6 @@ add_libc_unittest(
SUITE libc_linux_tests
SRCS syscall_test.cpp
DEPENDS
- syscall_impl_h
+ linux_syscall_h
support_common_h
)
diff --git a/libc/test/config/linux/x86_64/syscall_test.cpp b/libc/test/config/linux/x86_64/syscall_test.cpp
index 27628be6a4cd..efab1444d35c 100644
--- a/libc/test/config/linux/x86_64/syscall_test.cpp
+++ b/libc/test/config/linux/x86_64/syscall_test.cpp
@@ -6,7 +6,7 @@
//
//===----------------------------------------------------------------------===//
-#include "src/unistd/syscall.h"
+#include "config/linux/syscall.h"
#include "utils/UnitTest/Test.h"
#include <functional>
diff --git a/libc/test/src/sys/mman/CMakeLists.txt b/libc/test/src/sys/mman/CMakeLists.txt
index 3fcc8fff3c29..b4bbe81c92ff 100644
--- a/libc/test/src/sys/mman/CMakeLists.txt
+++ b/libc/test/src/sys/mman/CMakeLists.txt
@@ -1,15 +1,3 @@
-add_libc_testsuite(libc_sys_mman_unittests)
-
-add_libc_unittest(
- mmap_test
- SUITE
- libc_sys_mman_unittests
- SRCS
- mmap_test.cpp
- DEPENDS
- errno_h
- sys_mman_h
- mmap
- munmap
- __errno_location
-)
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+ add_subdirectory(${LIBC_TARGET_OS})
+endif()
diff --git a/libc/test/src/sys/mman/linux/CMakeLists.txt b/libc/test/src/sys/mman/linux/CMakeLists.txt
new file mode 100644
index 000000000000..3fcc8fff3c29
--- /dev/null
+++ b/libc/test/src/sys/mman/linux/CMakeLists.txt
@@ -0,0 +1,15 @@
+add_libc_testsuite(libc_sys_mman_unittests)
+
+add_libc_unittest(
+ mmap_test
+ SUITE
+ libc_sys_mman_unittests
+ SRCS
+ mmap_test.cpp
+ DEPENDS
+ errno_h
+ sys_mman_h
+ mmap
+ munmap
+ __errno_location
+)
diff --git a/libc/test/src/sys/mman/mmap_test.cpp b/libc/test/src/sys/mman/linux/mmap_test.cpp
similarity index 100%
rename from libc/test/src/sys/mman/mmap_test.cpp
rename to libc/test/src/sys/mman/linux/mmap_test.cpp
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