This commit adds memory operations on UML under !MMU environment.
Some part of the original UML code relying on CONFIG_MMU are excluded
from compilation when !CONFIG_MMU. Additionally, generic functions such as
uaccess, futex, memcpy/strnlen/strncpy can be used as user- and
kernel-space share the address space in !CONFIG_MMU mode.
Signed-off-by: Hajime Tazaki <thehaj...@gmail.com>
Signed-off-by: Ricardo Koller <ricar...@google.com>
---
arch/um/include/asm/futex.h | 4 ++++
arch/um/include/asm/mmu.h | 3 +++
arch/um/include/asm/mmu_context.h | 13 +++++++++++--
arch/um/include/asm/tlbflush.h | 22 ++++++++++++++++++++++
arch/um/include/asm/uaccess.h | 7 ++++---
arch/um/include/shared/os.h | 6 ++++++
arch/um/kernel/Makefile | 3 ++-
arch/um/kernel/mem.c | 12 +++++++++++-
arch/um/kernel/physmem.c | 6 ++++++
arch/um/kernel/skas/Makefile | 4 ++--
arch/um/kernel/trap.c | 4 ++++
arch/um/os-Linux/process.c | 4 ++--
12 files changed, 77 insertions(+), 11 deletions(-)
diff --git a/arch/um/include/asm/futex.h b/arch/um/include/asm/futex.h
index 780aa6bfc050..89a8ac0b6963 100644
--- a/arch/um/include/asm/futex.h
+++ b/arch/um/include/asm/futex.h
@@ -8,7 +8,11 @@
int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user
*uaddr);
+#ifdef CONFIG_MMU
int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval);
+#else
+#include <asm-generic/futex.h>
+#endif
#endif
diff --git a/arch/um/include/asm/mmu.h b/arch/um/include/asm/mmu.h
index 01422b761aa0..d4087f9499e2 100644
--- a/arch/um/include/asm/mmu.h
+++ b/arch/um/include/asm/mmu.h
@@ -15,10 +15,13 @@ typedef struct mm_context {
unsigned long sync_tlb_range_from;
unsigned long sync_tlb_range_to;
+#ifndef CONFIG_MMU
+ unsigned long end_brk;
#ifdef CONFIG_BINFMT_ELF_FDPIC
unsigned long exec_fdpic_loadmap;
unsigned long interp_fdpic_loadmap;
#endif
+#endif /* !CONFIG_MMU */
} mm_context_t;
#endif
diff --git a/arch/um/include/asm/mmu_context.h
b/arch/um/include/asm/mmu_context.h
index 23dcc914d44e..da287e8c86b3 100644
--- a/arch/um/include/asm/mmu_context.h
+++ b/arch/um/include/asm/mmu_context.h
@@ -37,10 +37,19 @@ static inline void switch_mm(struct mm_struct *prev, struct
mm_struct *next,
}
#define init_new_context init_new_context
-extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
-
#define destroy_context destroy_context
+#ifdef CONFIG_MMU
+extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
extern void destroy_context(struct mm_struct *mm);
+#else
+static inline int init_new_context(struct task_struct *task, struct mm_struct
*mm)
+{
+ return 0;
+}
+static inline void destroy_context(struct mm_struct *mm)
+{
+}
+#endif
#include <asm-generic/mmu_context.h>
diff --git a/arch/um/include/asm/tlbflush.h b/arch/um/include/asm/tlbflush.h
index 13a3009942be..9157f71695c6 100644
--- a/arch/um/include/asm/tlbflush.h
+++ b/arch/um/include/asm/tlbflush.h
@@ -30,6 +30,7 @@
* - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
*/
+#ifdef CONFIG_MMU
extern int um_tlb_sync(struct mm_struct *mm);
extern void flush_tlb_all(void);
@@ -55,5 +56,26 @@ static inline void flush_tlb_kernel_range(unsigned long
start,
/* Kernel needs to be synced immediately */
um_tlb_sync(&init_mm);
}
+#else
+static inline int um_tlb_sync(struct mm_struct *mm)
+{
+ return 0;
+}
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+ unsigned long address)
+{
+}
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+ unsigned long end)
+{
+}
+#endif
#endif
diff --git a/arch/um/include/asm/uaccess.h b/arch/um/include/asm/uaccess.h
index 1d4b6bbc1b65..9bfee12cb6b7 100644
--- a/arch/um/include/asm/uaccess.h
+++ b/arch/um/include/asm/uaccess.h
@@ -22,6 +22,7 @@
#define __addr_range_nowrap(addr, size) \
((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
+#ifdef CONFIG_MMU
extern unsigned long raw_copy_from_user(void *to, const void __user *from,
unsigned long n);
extern unsigned long raw_copy_to_user(void __user *to, const void *from,
unsigned long n);
extern unsigned long __clear_user(void __user *mem, unsigned long len);
@@ -33,9 +34,6 @@ static inline int __access_ok(const void __user *ptr,
unsigned long size);
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
-
-#include <asm-generic/uaccess.h>
-
static inline int __access_ok(const void __user *ptr, unsigned long size)
{
unsigned long addr = (unsigned long)ptr;
@@ -43,6 +41,9 @@ static inline int __access_ok(const void __user *ptr,
unsigned long size)
(__under_task_size(addr, size) ||
__access_ok_vsyscall(addr, size));
}
+#endif
+
+#include <asm-generic/uaccess.h>
/* no pagefaults for kernel addresses in um */
#define __get_kernel_nofault(dst, src, type, err_label)
\
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index 5babad8c5f75..6874be0c38a8 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -195,7 +195,13 @@ extern void get_host_cpu_features(
extern int create_mem_file(unsigned long long len);
/* tlb.c */
+#ifdef CONFIG_MMU
extern void report_enomem(void);
+#else
+static inline void report_enomem(void)
+{
+}
+#endif
/* process.c */
extern void os_alarm_process(int pid);
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index f8567b933ffa..b41e9bcabbe3 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -16,9 +16,10 @@ extra-y := vmlinux.lds
obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \
physmem.o process.o ptrace.o reboot.o sigio.o \
- signal.o sysrq.o time.o tlb.o trap.o \
+ signal.o sysrq.o time.o trap.o \
um_arch.o umid.o maccess.o kmsg_dump.o capflags.o skas/
obj-y += load_file.o
+obj-$(CONFIG_MMU) += tlb.o
obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
obj-$(CONFIG_GPROF) += gprof_syms.o
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 53248ed04771..b674017d9871 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -64,7 +64,8 @@ void __init mem_init(void)
* to be turned on.
*/
brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
- map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
+ map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1,
+ !IS_ENABLED(CONFIG_MMU));
memblock_free((void *)brk_end, uml_reserved - brk_end);
uml_reserved = brk_end;
@@ -78,6 +79,7 @@ void __init mem_init(void)
* Create a page table and place a pointer to it in a middle page
* directory entry.
*/
+#ifdef CONFIG_MMU
static void __init one_page_table_init(pmd_t *pmd)
{
if (pmd_none(*pmd)) {
@@ -149,6 +151,12 @@ static void __init fixrange_init(unsigned long start,
unsigned long end,
j = 0;
}
}
+#else
+static void __init fixrange_init(unsigned long start, unsigned long end,
+ pgd_t *pgd_base)
+{
+}
+#endif
static void __init fixaddr_user_init( void)
{
@@ -230,6 +238,7 @@ void *uml_kmalloc(int size, int flags)
return kmalloc(size, flags);
}
+#ifdef CONFIG_MMU
static const pgprot_t protection_map[16] = {
[VM_NONE] = PAGE_NONE,
[VM_READ] = PAGE_READONLY,
@@ -249,3 +258,4 @@ static const pgprot_t protection_map[16] = {
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED
};
DECLARE_VM_GET_PAGE_PROT
+#endif
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index a74f17b033c4..f55d46dbe173 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -84,7 +84,11 @@ void __init setup_physmem(unsigned long start, unsigned long
reserve_end,
exit(1);
}
+#ifdef CONFIG_MMU
physmem_fd = create_mem_file(len);
+#else
+ physmem_fd = -1;
+#endif
err = os_map_memory((void *) reserve_end, physmem_fd, reserve,
map_size, 1, 1, 1);
@@ -95,12 +99,14 @@ void __init setup_physmem(unsigned long start, unsigned
long reserve_end,
exit(1);
}
+#ifdef CONFIG_MMU
/*
* Special kludge - This page will be mapped in to userspace processes
* from physmem_fd, so it needs to be written out there.
*/
os_seek_file(physmem_fd, __pa(__syscall_stub_start));
os_write_file(physmem_fd, __syscall_stub_start, PAGE_SIZE);
+#endif
memblock_add(__pa(start), len);
memblock_reserve(__pa(start), reserve);
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index 3384be42691f..64d7ba803b1a 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -3,8 +3,8 @@
# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
#
-obj-y := stub.o mmu.o process.o syscall.o uaccess.o \
- stub_exe_embed.o
+obj-y := stub.o process.o stub_exe_embed.o
+obj-$(CONFIG_MMU) += mmu.o syscall.o uaccess.o
# Stub executable
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index cdaee3e94273..a7519b3de4bf 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -24,6 +24,7 @@
int handle_page_fault(unsigned long address, unsigned long ip,
int is_write, int is_user, int *code_out)
{
+#ifdef CONFIG_MMU
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
pmd_t *pmd;
@@ -129,6 +130,9 @@ int handle_page_fault(unsigned long address, unsigned long
ip,
goto out_nosemaphore;
pagefault_out_of_memory();
return 0;
+#else
+ return -EFAULT;
+#endif
}
static void show_segv_info(struct uml_pt_regs *regs)
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 9f086f939420..ef1a2f0aa06a 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -63,8 +63,8 @@ int os_map_memory(void *virt, int fd, unsigned long long off,
unsigned long len,
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
- loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
- fd, off);
+ loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED |
+ (!IS_ENABLED(CONFIG_MMU) ? MAP_ANONYMOUS : 0), fd, off);
if (loc == MAP_FAILED)
return -errno;
return 0;
--
2.43.0
