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

[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

arch/um/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/um/kernel/tt/Makefile

+0 −15
Original line number Diff line number Diff line
@@ -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

arch/um/kernel/uml.lds.S

+3 −12
Original line number Diff line number Diff line
@@ -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

arch/um/scripts/Makefile.rules

+6 −0
Original line number Diff line number Diff line
@@ -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 $@) $@

arch/um/scripts/Makefile.unmap

0 → 100644
+22 −0
Original line number Diff line number Diff line 
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

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