Commit 60b2737d authored by Paolo 'Blaisorblade' Giarrusso's avatar Paolo 'Blaisorblade' Giarrusso Committed by Linus Torvalds

[PATCH] uml: fix linkage of tt mode against NPTL

With Al Viro <viro@parcelfarce.linux.theplanet.co.uk>

To make sure switcheroo() can execute when we remap all the executable
image, we used a trick to make it use a local copy of errno...  this trick
does not work with NPTL glibc, only with LinuxThreads, so use another
(simpler) one to make it work anyway.

Hopefully, a lot improved thanks to merging with the version of Al Viro
(which had his part of problems, though, i.e.  removing a fix to another
bug and not fixing the problem on i386).
Signed-off-by: default avatarPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b77d6adc
......@@ -122,7 +122,7 @@ endif
CPPFLAGS_vmlinux.lds = $(shell echo -U$(SUBARCH) \
-DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \
-DELF_FORMAT=\"$(ELF_FORMAT)\" $(CPP_MODE-y) \
-DKERNEL_STACK_SIZE=$(STACK_SIZE))
-DKERNEL_STACK_SIZE=$(STACK_SIZE) -DSUBARCH=$(SUBARCH))
#The wrappers will select whether using "malloc" or the kernel allocator.
LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
......
......@@ -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 ptproxy/
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
......@@ -14,19 +14,10 @@ SECTIONS
/* Used in arch/um/kernel/mem.c. Any memory between START and __binary_start
* 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.*/
#ifdef MODE_TT
.remap_data : { arch/um/sys-SUBARCH/unmap_fin.o (.data .bss) }
.remap : { arch/um/sys-SUBARCH/unmap_fin.o (.text) }
. = ALIGN(4096); /* Init code and data */
#endif
......
......@@ -10,6 +10,12 @@ USER_OBJS := $(foreach file,$(USER_OBJS),$(obj)/$(file))
$(USER_OBJS) : c_flags = -Wp,-MD,$(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 $@) $@
......
clean-files += unmap_tmp.o unmap_fin.o unmap.o
ifdef CONFIG_MODE_TT
#Always build unmap_fin.o
extra-y += unmap_fin.o
#Do dependency tracking for unmap.o (it will be always built, but won't get the tracking unless we use this).
targets += unmap.o
#XXX: partially copied from arch/um/scripts/Makefile.rules
$(obj)/unmap.o: _c_flags = $(call unprofile,$(CFLAGS))
quiet_cmd_wrapld = LD $@
define cmd_wrapld
$(LD) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) -print-file-name=libc.a); \
$(OBJCOPY) $(obj)/unmap_tmp.o $@ -G switcheroo
endef
$(obj)/unmap_fin.o : $(obj)/unmap.o FORCE
$(call if_changed,wrapld)
endif
......@@ -17,3 +17,5 @@ highmem.c-dir = mm
module.c-dir = kernel
subdir- := util
include arch/um/scripts/Makefile.unmap
/*
/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <sys/mman.h>
#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(mmap(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
if(mmap2(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
return(-1);
}
if(munmap(from, size) < 0){
......@@ -18,14 +23,3 @@ int switcheroo(int fd, int prot, void *from, void *to, int size)
}
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:
*/
......@@ -29,3 +29,5 @@ thunk.S-dir = lib
module.c-dir = kernel
subdir- := util
include arch/um/scripts/Makefile.unmap
/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* 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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