[PATCH 3/5] UML - Clean up tt mode remapping of UML binary

From: Jeff Dike
Date: Mon Jun 06 2005 - 17:32:07 EST

>From Al Viro - this turns the tt mode remapping of the binary into arch
code.

Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxx>

Index: linux-2.6.12-rc/arch/um/Makefile
===================================================================
--- linux-2.6.12-rc.orig/arch/um/Makefile 2005-06-02 17:04:01.000000000 -0400
+++ linux-2.6.12-rc/arch/um/Makefile 2005-06-06 11:36:06.000000000 -0400
@@ -119,7 +119,7 @@ ifndef START
START = $$(($(TOP_ADDR) - $(SIZE)))
endif

-CPPFLAGS_vmlinux.lds = $(shell echo -U$(SUBARCH) \
+CPPFLAGS_vmlinux.lds = $(shell echo -U$(SUBARCH) -I$(SYS_DIR) \
-DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \
-DELF_FORMAT=\"$(ELF_FORMAT)\" $(CPP_MODE-y) \
-DKERNEL_STACK_SIZE=$(STACK_SIZE))
Index: linux-2.6.12-rc/arch/um/include/sysdep-i386/unmap.lds
===================================================================
--- linux-2.6.12-rc.orig/arch/um/include/sysdep-i386/unmap.lds 2005-06-06 05:54:35.815704808 -0400
+++ linux-2.6.12-rc/arch/um/include/sysdep-i386/unmap.lds 2005-06-02 17:04:44.000000000 -0400
@@ -0,0 +1,14 @@
+ .thread_private : {
+ __start_thread_private = .;
+ errno = .;
+ . += 4;
+ arch/um/sys-i386/unmap_fin.o (.bss)
+ __end_thread_private = .;
+ }
+ . = ALIGN(4096);
+ .remap : { arch/um/sys-i386/unmap_fin.o (.text) }
+
+ /* We want it only if we are in MODE_TT. In both cases, however, when MODE_TT
+ * is off the resulting binary segfaults.*/
+
+ . = ALIGN(4096); /* Init code and data */
Index: linux-2.6.12-rc/arch/um/include/sysdep-x86_64/unmap.lds
===================================================================
--- linux-2.6.12-rc.orig/arch/um/include/sysdep-x86_64/unmap.lds 2005-06-06 05:54:35.815704808 -0400
+++ linux-2.6.12-rc/arch/um/include/sysdep-x86_64/unmap.lds 2005-06-02 17:04:44.000000000 -0400
@@ -0,0 +1,6 @@
+ . = ALIGN(4096); /* Init code and data */
+ .remap : {
+ arch/um/sys-x86_64/unmap_fin.o (.bss)
+ arch/um/sys-x86_64/unmap_fin.o (.text)
+ }
+ . = ALIGN(4096); /* Init code and data */
Index: linux-2.6.12-rc/arch/um/kernel/tt/Makefile
===================================================================
--- linux-2.6.12-rc.orig/arch/um/kernel/tt/Makefile 2005-06-02 17:04:01.000000000 -0400
+++ linux-2.6.12-rc/arch/um/kernel/tt/Makefile 2005-06-06 11:52:11.000000000 -0400
@@ -3,10 +3,6 @@
# Licensed under the GPL
#

-extra-y := unmap_fin.o
-targets := unmap.o
-clean-files := unmap_tmp.o
-
obj-y = exec_kern.o exec_user.o gdb.o ksyms.o mem.o mem_user.o process_kern.o \
syscall_kern.o syscall_user.o time.o tlb.o tracer.o trap_user.o \
uaccess.o uaccess_user.o
@@ -16,14 +12,3 @@ obj-$(CONFIG_PT_PROXY) += gdb_kern.o ptp
USER_OBJS := gdb.o time.o tracer.o

include arch/um/scripts/Makefile.rules
-
-UNMAP_CFLAGS := $(patsubst -pg -DPROFILING,,$(USER_CFLAGS))
-UNMAP_CFLAGS := $(patsubst -fprofile-arcs -ftest-coverage,,$(UNMAP_CFLAGS))
-
-#XXX: partially copied from arch/um/scripts/Makefile.rules
-$(obj)/unmap.o: c_flags = -Wp,-MD,$(depfile) $(UNMAP_CFLAGS)
-
-$(obj)/unmap_fin.o : $(obj)/unmap.o
- $(LD) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) -print-file-name=libc.a)
- $(OBJCOPY) $(obj)/unmap_tmp.o $@ -G switcheroo
-
Index: linux-2.6.12-rc/arch/um/kernel/tt/unmap.c
===================================================================
--- linux-2.6.12-rc.orig/arch/um/kernel/tt/unmap.c 2005-06-02 17:04:01.000000000 -0400
+++ linux-2.6.12-rc/arch/um/kernel/tt/unmap.c 2005-06-06 05:54:35.815704808 -0400
@@ -1,31 +0,0 @@
-/*
- * Copyright (C) 2000 Jeff Dike (jdike@xxxxxxxxxx)
- * Licensed under the GPL
- */
-
-#include <sys/mman.h>
-
-int switcheroo(int fd, int prot, void *from, void *to, int size)
-{
- if(munmap(to, size) < 0){
- return(-1);
- }
- if(mmap(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
- return(-1);
- }
- if(munmap(from, size) < 0){
- return(-1);
- }
- return(0);
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
Index: linux-2.6.12-rc/arch/um/kernel/uml.lds.S
===================================================================
--- linux-2.6.12-rc.orig/arch/um/kernel/uml.lds.S 2005-06-02 17:04:01.000000000 -0400
+++ linux-2.6.12-rc/arch/um/kernel/uml.lds.S 2005-06-06 11:52:10.000000000 -0400
@@ -15,20 +15,7 @@ SECTIONS
* is remapped.*/
__binary_start = .;
#ifdef MODE_TT
- .thread_private : {
- __start_thread_private = .;
- errno = .;
- . += 4;
- arch/um/kernel/tt/unmap_fin.o (.data)
- __end_thread_private = .;
- }
- . = ALIGN(4096);
- .remap : { arch/um/kernel/tt/unmap_fin.o (.text) }
-
- /* We want it only if we are in MODE_TT. In both cases, however, when MODE_TT
- * is off the resulting binary segfaults.*/
-
- . = ALIGN(4096); /* Init code and data */
+#include <unmap.lds>
#endif

_stext = .;
Index: linux-2.6.12-rc/arch/um/scripts/Makefile.rules
===================================================================
--- linux-2.6.12-rc.orig/arch/um/scripts/Makefile.rules 2005-06-06 12:14:26.000000000 -0400
+++ linux-2.6.12-rc/arch/um/scripts/Makefile.rules 2005-06-06 12:15:45.000000000 -0400
@@ -10,6 +10,11 @@ USER_OBJS := $(foreach file,$(USER_OBJS)
$(USER_OBJS) : c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) \
$(CFLAGS_$(notdir $@))

+# The stubs and unmap.o can't try to call mcount or update basic block data
+define unprofile
+ $(patsubst -pg,,$(patsubst -fprofile-arcs -ftest-coverage,,$(1)))
+endef
+
quiet_cmd_make_link = SYMLINK $@
cmd_make_link = ln -sf $(srctree)/arch/$(SUBARCH)/$($(notdir $@)-dir)/$(notdir $@) $@

Index: linux-2.6.12-rc/arch/um/sys-i386/Makefile
===================================================================
--- linux-2.6.12-rc.orig/arch/um/sys-i386/Makefile 2005-06-02 17:04:01.000000000 -0400
+++ linux-2.6.12-rc/arch/um/sys-i386/Makefile 2005-06-06 11:52:10.000000000 -0400
@@ -2,6 +2,8 @@ obj-y = bitops.o bugs.o checksum.o delay
ptrace_user.o semaphore.o signal.o sigcontext.o syscalls.o sysrq.o \
sys_call_table.o

+extra-$(CONFIG_MODE_TT) := unmap_fin.o
+
obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_MODULES) += module.o

@@ -16,4 +18,6 @@ semaphore.c-dir = kernel
highmem.c-dir = mm
module.c-dir = kernel

+$(obj)/unmap_fin.o : _c_flags = $(call unprofile,$(CFLAGS))
+
subdir- := util
Index: linux-2.6.12-rc/arch/um/sys-i386/unmap_fin.c
===================================================================
--- linux-2.6.12-rc.orig/arch/um/sys-i386/unmap_fin.c 2005-06-06 05:54:35.815704808 -0400
+++ linux-2.6.12-rc/arch/um/sys-i386/unmap_fin.c 2005-06-03 15:36:17.000000000 -0400
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike (jdike@xxxxxxxxxx)
+ * Licensed under the GPL
+ */
+
+#include <linux/mman.h>
+#include <asm/unistd.h>
+
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap2,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
+int switcheroo(int fd, int prot, void *from, void *to, int size)
+{
+ if(munmap(to, size) < 0){
+ return(-1);
+ }
+ if(mmap2(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
+ return(-1);
+ }
+ if(munmap(from, size) < 0){
+ return(-1);
+ }
+ return(0);
+}
Index: linux-2.6.12-rc/arch/um/sys-x86_64/Makefile
===================================================================
--- linux-2.6.12-rc.orig/arch/um/sys-x86_64/Makefile 2005-06-02 17:04:01.000000000 -0400
+++ linux-2.6.12-rc/arch/um/sys-x86_64/Makefile 2005-06-06 11:52:10.000000000 -0400
@@ -4,6 +4,8 @@
# Licensed under the GPL
#

+extra-$(CONFIG_MODE_TT) := unmap_fin.o
+
#XXX: why into lib-y?
lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o mem.o memcpy.o \
ptrace.o ptrace_user.o semaphore.o sigcontext.o signal.o \
@@ -29,3 +31,5 @@ thunk.S-dir = lib
module.c-dir = kernel

subdir- := util
+
+$(obj)/unmap_fin.o: _c_flags = $(call unprofile,$(CFLAGS))
Index: linux-2.6.12-rc/arch/um/sys-x86_64/unmap_fin.c
===================================================================
--- linux-2.6.12-rc.orig/arch/um/sys-x86_64/unmap_fin.c 2005-06-06 05:54:35.815704808 -0400
+++ linux-2.6.12-rc/arch/um/sys-x86_64/unmap_fin.c 2005-06-02 17:04:44.000000000 -0400
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike (jdike@xxxxxxxxxx)
+ * Licensed under the GPL
+ */
+
+#include <linux/mman.h>
+#include <asm/unistd.h>
+
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
+int switcheroo(int fd, int prot, void *from, void *to, int size)
+{
+ if(munmap(to, size) < 0){
+ return(-1);
+ }
+ if(mmap(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
+ return(-1);
+ }
+ if(munmap(from, size) < 0){
+ return(-1);
+ }
+ return(0);
+}

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