[RFC v7 17/21] um: host: add nommu build for ARCH=um

Hajime Tazaki thehajime at gmail.com
Tue Oct 6 05:44:26 EDT 2020


This patch adds the skeleton for the host library.

The host library is implementing the host operations needed by nommu
mode and is split into host dependent (depends on a specific host, e.g.
POSIX hosts) and host independent parts (will work on all supported
hosts).

Signed-off-by: Hajime Tazaki <thehajime at gmail.com>
Signed-off-by: Octavian Purdila <tavi.purdila at gmail.com>
---
 tools/um/.gitignore                |   1 +
 tools/um/Makefile                  |  32 +++---
 tools/um/Targets                   |   3 +-
 tools/um/include/lkl.h             | 151 +++++++++++++++++++++++++++++
 tools/um/include/lkl_host.h        |  26 +++++
 tools/um/uml/Build                 |  16 ++-
 tools/um/uml/nommu/Build           |   1 +
 tools/um/uml/nommu/registers.c     |  21 ++++
 tools/um/uml/nommu/unimplemented.c |  21 ++++
 9 files changed, 252 insertions(+), 20 deletions(-)
 create mode 100644 tools/um/.gitignore
 create mode 100644 tools/um/include/lkl.h
 create mode 100644 tools/um/include/lkl_host.h
 create mode 100644 tools/um/uml/nommu/Build
 create mode 100644 tools/um/uml/nommu/registers.c
 create mode 100644 tools/um/uml/nommu/unimplemented.c

diff --git a/tools/um/.gitignore b/tools/um/.gitignore
new file mode 100644
index 000000000000..0d20b6487c61
--- /dev/null
+++ b/tools/um/.gitignore
@@ -0,0 +1 @@
+*.pyc
diff --git a/tools/um/Makefile b/tools/um/Makefile
index 552ed5f1edae..bbd5e0dcadbc 100644
--- a/tools/um/Makefile
+++ b/tools/um/Makefile
@@ -5,6 +5,7 @@
 MAKEFLAGS += -r --no-print-directory
 
 KCONFIG?=defconfig
+UMMODE?=kernel
 
 ifneq ($(silent),1)
   ifneq ($(V),1)
@@ -15,10 +16,8 @@ endif
 
 PREFIX   := /usr
 
-ifeq (,$(srctree))
-  srctree := $(patsubst %/,%,$(dir $(shell pwd)))
-  srctree := $(patsubst %/,%,$(dir $(srctree)))
-endif
+srctree := $(patsubst %/,%,$(dir $(shell pwd)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
 export srctree
 
 -include ../scripts/Makefile.include
@@ -32,9 +31,6 @@ endif
 export OUTPUT
 export objtree := $(OUTPUT)/../..
 
-
-all:
-
 export CFLAGS += -I$(OUTPUT)/include -Iinclude -Wall -g -O2 -Wextra -fPIC \
 	 -Wno-unused-parameter \
 	 -Wno-missing-field-initializers -fno-strict-aliasing
@@ -45,28 +41,34 @@ TARGETS := $(progs-y:%=$(OUTPUT)%)
 TARGETS += $(libs-y:%=$(OUTPUT)%)
 all: $(TARGETS)
 
-# rule to build linux.o
-$(OUTPUT)lib/linux.o:
-	$(Q)CFLAGS= $(MAKE) -C ../.. ARCH=um $(KOPT) $(KCONFIG)
-	$(Q)CFLAGS= $(MAKE) -C ../.. ARCH=um $(KOPT) install INSTALL_PATH=$(OUTPUT)
+$(objtree)/linux.o:
+	$(Q)echo ""
+	$(Q)echo ""
+	$(Q)echo "==> $@ isn't found; please make ARCH=um"
+	$(Q)echo ""
+	$(Q)echo ""
+	$(Q)exit 1
 
-$(OUTPUT)liblinux.a: $(OUTPUT)lib/linux.o $(OUTPUT)uml/liblinux-in.o $(OUTPUT)lib/liblinux-in.o
+$(OUTPUT)lib/linux.o: $(objtree)/linux.o
+	$(Q)cp $(objtree)/linux.o $(OUTPUT)lib/linux.o
+
+# rule to build linux.o
+$(OUTPUT)liblinux.a: $(OUTPUT)uml/liblinux-in.o $(OUTPUT)lib/liblinux-in.o $(OUTPUT)lib/linux.o
 	$(QUIET_AR)$(AR) -rc $@ $^
 
 # rule to link programs
 $(OUTPUT)%: $(OUTPUT)%-in.o $(OUTPUT)liblinux.a
 	$(QUIET_LINK)$(CC) $(LDFLAGS) $(LDFLAGS_$(notdir $*)-y) -o $@ $^ $(LDLIBS) $(LDLIBS_$(notdir $*)-y)
 
-$(OUTPUT)%-in.o: FORCE
-	$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(patsubst %/,%,$(dir $*)) obj=$(notdir $*)
-
 # rule to build objects
 $(OUTPUT)%-in.o: $(OUTPUT)lib/linux.o FORCE
 	$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(patsubst %/,%,$(dir $*)) obj=$(notdir $*)
 
+RM := rm -f
 clean:
 	$(call QUIET_CLEAN, objects)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd'\
 	 -delete -o -name '\.*.d' -delete
+	$(call QUIET_CLEAN, headers)$(RM) -r $(OUTPUT)/include/lkl/
 	$(call QUIET_CLEAN, liblinux.a)$(RM) $(OUTPUT)/liblinux.a
 	$(call QUIET_CLEAN, $(TARGETS))$(RM) $(TARGETS)
 
diff --git a/tools/um/Targets b/tools/um/Targets
index a4711f1ef422..4e1f0f4d81a3 100644
--- a/tools/um/Targets
+++ b/tools/um/Targets
@@ -1,4 +1,5 @@
 progs-y += uml/linux
-LDLIBS_linux-y := -lrt -lpthread -lutil
+
+LDLIBS := -lrt -lpthread -lutil
 LDFLAGS_linux-y := -no-pie -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
 LDFLAGS_linux-$(UML_STATIC) += -static
diff --git a/tools/um/include/lkl.h b/tools/um/include/lkl.h
new file mode 100644
index 000000000000..707e01b64a70
--- /dev/null
+++ b/tools/um/include/lkl.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LKL_H
+#define _LKL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define _LKL_LIBC_COMPAT_H
+
+#ifdef __cplusplus
+#define class __lkl__class
+#endif
+
+/*
+ * Avoid collisions between Android which defines __unused and
+ * linux/icmp.h which uses __unused as a structure field.
+ */
+#pragma push_macro("__unused")
+#undef __unused
+
+#include <lkl/asm/syscalls.h>
+
+#pragma pop_macro("__unused")
+
+#ifdef __cplusplus
+#undef class
+#endif
+
+/**
+ * lkl_strerror - returns a string describing the given error code
+ *
+ * @err - error code
+ * @returns - string for the given error code
+ */
+const char *lkl_strerror(int err);
+
+/**
+ * lkl_perror - prints a string describing the given error code
+ *
+ * @msg - prefix for the error message
+ * @err - error code
+ */
+void lkl_perror(char *msg, int err);
+
+#if __LKL__BITS_PER_LONG == 64
+#define lkl_sys_fstatat lkl_sys_newfstatat
+#define lkl_sys_fstat lkl_sys_newfstat
+
+#else
+#define __lkl__NR_fcntl __lkl__NR_fcntl64
+
+#define lkl_stat lkl_stat64
+#define lkl_sys_stat lkl_sys_stat64
+#define lkl_sys_lstat lkl_sys_lstat64
+#define lkl_sys_truncate lkl_sys_truncate64
+#define lkl_sys_ftruncate lkl_sys_ftruncate64
+#define lkl_sys_sendfile lkl_sys_sendfile64
+#define lkl_sys_fstatat lkl_sys_fstatat64
+#define lkl_sys_fstat lkl_sys_fstat64
+#define lkl_sys_fcntl lkl_sys_fcntl64
+
+#define lkl_statfs lkl_statfs64
+
+static inline int lkl_sys_statfs(const char *path, struct lkl_statfs *buf)
+{
+	return lkl_sys_statfs64(path, sizeof(*buf), buf);
+}
+
+static inline int lkl_sys_fstatfs(unsigned int fd, struct lkl_statfs *buf)
+{
+	return lkl_sys_fstatfs64(fd, sizeof(*buf), buf);
+}
+
+#define lkl_sys_nanosleep lkl_sys_nanosleep_time32
+static inline int lkl_sys_nanosleep_time32(struct lkl_timespec *rqtp,
+					   struct lkl_timespec *rmtp)
+{
+	long p[6] = {(long)rqtp, (long)rmtp, 0, 0, 0, 0};
+
+	return lkl_syscall(__lkl__NR_nanosleep, p);
+}
+
+#endif
+
+static inline int lkl_sys_stat(const char *path, struct lkl_stat *buf)
+{
+	return lkl_sys_fstatat(LKL_AT_FDCWD, path, buf, 0);
+}
+
+static inline int lkl_sys_lstat(const char *path, struct lkl_stat *buf)
+{
+	return lkl_sys_fstatat(LKL_AT_FDCWD, path, buf,
+			       LKL_AT_SYMLINK_NOFOLLOW);
+}
+
+#ifdef __lkl__NR_openat
+/**
+ * lkl_sys_open - wrapper for lkl_sys_openat
+ */
+static inline long lkl_sys_open(const char *file, int flags, int mode)
+{
+	return lkl_sys_openat(LKL_AT_FDCWD, file, flags, mode);
+}
+
+/**
+ * lkl_sys_creat - wrapper for lkl_sys_openat
+ */
+static inline long lkl_sys_creat(const char *file, int mode)
+{
+	return lkl_sys_openat(LKL_AT_FDCWD, file,
+			      LKL_O_CREAT|LKL_O_WRONLY|LKL_O_TRUNC, mode);
+}
+#endif
+
+#ifdef __lkl__NR_mkdirat
+/**
+ * lkl_sys_mkdir - wrapper for lkl_sys_mkdirat
+ */
+static inline long lkl_sys_mkdir(const char *path, mode_t mode)
+{
+	return lkl_sys_mkdirat(LKL_AT_FDCWD, path, mode);
+}
+#endif
+
+#ifdef __lkl__NR_epoll_create1
+/**
+ * lkl_sys_epoll_create - wrapper for lkl_sys_epoll_create1
+ */
+static inline long lkl_sys_epoll_create(int size)
+{
+	return lkl_sys_epoll_create1(0);
+}
+#endif
+
+#ifdef __lkl__NR_epoll_pwait
+/**
+ * lkl_sys_epoll_wait - wrapper for lkl_sys_epoll_pwait
+ */
+static inline long lkl_sys_epoll_wait(int fd, struct lkl_epoll_event *ev,
+				      int cnt, int to)
+{
+	return lkl_sys_epoll_pwait(fd, ev, cnt, to, 0, _LKL_NSIG/8);
+}
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/um/include/lkl_host.h b/tools/um/include/lkl_host.h
new file mode 100644
index 000000000000..85e80eb4ad0d
--- /dev/null
+++ b/tools/um/include/lkl_host.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LKL_HOST_H
+#define _LKL_HOST_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <lkl/asm/host_ops.h>
+#include <lkl.h>
+
+extern struct lkl_host_operations lkl_host_ops;
+
+/**
+ * lkl_printf - print a message via the host print operation
+ *
+ * @fmt: printf like format string
+ */
+int lkl_printf(const char *fmt, ...);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/um/uml/Build b/tools/um/uml/Build
index 0d87d601bc06..a55c5cc3ebc0 100644
--- a/tools/um/uml/Build
+++ b/tools/um/uml/Build
@@ -8,11 +8,19 @@ KCOV_INSTRUMENT                := n
 
 include $(objtree)/include/config/auto.conf
 
-liblinux-y += execvp.o file.o helper.o irq.o main.o mem.o process.o \
-	registers.o sigio.o signal.o start_up.o time.o tty.o \
-	umid.o util.o drivers/ skas/
+liblinux-y += execvp.o file.o helper.o irq.o mem.o process.o \
+	registers.o sigio.o signal.o time.o tty.o \
+	umid.o util.o drivers/
 
+ifdef CONFIG_MMU
+liblinux-y += main.o start_up.o skas/
+HEADER_ARCH 	:= x86
 liblinux-y += x86/
+else
+HEADER_ARCH 	:= um/nommu
+liblinux-y += nommu/
+endif
+
 
 liblinux-$(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA) += elf_aux.o
 
@@ -23,7 +31,6 @@ CFLAGS := -g -O2
 
 # from arch/um/Makefile
 ARCH_DIR := arch/um
-HEADER_ARCH 	:= x86
 HOST_DIR := arch/$(HEADER_ARCH)
 ifdef CONFIG_64BIT
   KBUILD_CFLAGS += -mcmodel=large
@@ -33,6 +40,7 @@ KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \
 	-Dlongjmp=kernel_longjmp -Dsetjmp=kernel_setjmp \
 	-Din6addr_loopback=kernel_in6addr_loopback \
 	-Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr
+KBUILD_CFLAGS := $(filter-out -Dsigprocmask=kernel_sigprocmask,$(KBUILD_CFLAGS))
 SHARED_HEADERS	:= $(ARCH_DIR)/include/shared
 MODE_INCLUDE	+= -I$(srctree)/$(ARCH_DIR)/include/shared/skas
 ARCH_INCLUDE	:= -I$(srctree)/$(SHARED_HEADERS)
diff --git a/tools/um/uml/nommu/Build b/tools/um/uml/nommu/Build
new file mode 100644
index 000000000000..98fd6b86a085
--- /dev/null
+++ b/tools/um/uml/nommu/Build
@@ -0,0 +1 @@
+liblinux-y = registers.o unimplemented.o
diff --git a/tools/um/uml/nommu/registers.c b/tools/um/uml/nommu/registers.c
new file mode 100644
index 000000000000..11573a204720
--- /dev/null
+++ b/tools/um/uml/nommu/registers.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+struct uml_pt_regs;
+
+int get_fp_registers(int pid, unsigned long *regs)
+{
+	return 0;
+}
+
+int save_i387_registers(int pid, unsigned long *fp_regs)
+{
+	return 0;
+}
+
+void arch_init_registers(int pid)
+{
+}
+
+void get_regs_from_mc(struct uml_pt_regs *regs, void *mc)
+{
+}
diff --git a/tools/um/uml/nommu/unimplemented.c b/tools/um/uml/nommu/unimplemented.c
new file mode 100644
index 000000000000..9da3e5c8bafb
--- /dev/null
+++ b/tools/um/uml/nommu/unimplemented.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <generated/user_constants.h>
+
+struct uml_pt_regs;
+
+/* os-Linux/skas/process.c */
+int userspace_pid[UM_NR_CPUS];
+void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
+{}
+
+
+/* x86/os-Linux/task_size.c */
+unsigned long os_get_top_address(void)
+{
+	return 0;
+}
+
+/* start-up.c */
+void os_early_checks(void)
+{
+}
-- 
2.21.0 (Apple Git-122.2)




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