From: Paolo 'Blaisorblade' Giarrusso , Al Viro 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: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton --- dev/null | 31 ------------------------------- arch/um/Makefile | 2 +- arch/um/kernel/tt/Makefile | 15 --------------- arch/um/kernel/uml.lds.S | 15 +++------------ arch/um/scripts/Makefile.rules | 6 ++++++ arch/um/scripts/Makefile.unmap | 22 ++++++++++++++++++++++ arch/um/sys-i386/Makefile | 2 ++ arch/um/sys-i386/unmap.c | 25 +++++++++++++++++++++++++ arch/um/sys-x86_64/Makefile | 2 ++ arch/um/sys-x86_64/unmap.c | 25 +++++++++++++++++++++++++ 10 files changed, 86 insertions(+), 59 deletions(-) diff -puN arch/um/kernel/tt/Makefile~uml-link-tt-mode-against-nptl arch/um/kernel/tt/Makefile --- 25/arch/um/kernel/tt/Makefile~uml-link-tt-mode-against-nptl 2005-06-06 21:25:16.000000000 -0700 +++ 25-akpm/arch/um/kernel/tt/Makefile 2005-06-06 21:25:16.000000000 -0700 @@ -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 - diff -L arch/um/kernel/tt/unmap.c -puN arch/um/kernel/tt/unmap.c~uml-link-tt-mode-against-nptl /dev/null --- 25/arch/um/kernel/tt/unmap.c +++ /dev/null 2003-09-15 06:40:47.000000000 -0700 @@ -1,31 +0,0 @@ -/* - * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) - * Licensed under the GPL - */ - -#include - -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: - */ diff -puN arch/um/kernel/uml.lds.S~uml-link-tt-mode-against-nptl arch/um/kernel/uml.lds.S --- 25/arch/um/kernel/uml.lds.S~uml-link-tt-mode-against-nptl 2005-06-06 21:25:16.000000000 -0700 +++ 25-akpm/arch/um/kernel/uml.lds.S 2005-06-06 21:25:16.000000000 -0700 @@ -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 diff -puN arch/um/Makefile~uml-link-tt-mode-against-nptl arch/um/Makefile --- 25/arch/um/Makefile~uml-link-tt-mode-against-nptl 2005-06-06 21:25:16.000000000 -0700 +++ 25-akpm/arch/um/Makefile 2005-06-06 21:25:16.000000000 -0700 @@ -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 diff -puN arch/um/scripts/Makefile.rules~uml-link-tt-mode-against-nptl arch/um/scripts/Makefile.rules --- 25/arch/um/scripts/Makefile.rules~uml-link-tt-mode-against-nptl 2005-06-06 21:25:16.000000000 -0700 +++ 25-akpm/arch/um/scripts/Makefile.rules 2005-06-06 21:25:16.000000000 -0700 @@ -10,6 +10,12 @@ 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 $@) $@ diff -puN /dev/null arch/um/scripts/Makefile.unmap --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ 25-akpm/arch/um/scripts/Makefile.unmap 2005-06-06 21:25:16.000000000 -0700 @@ -0,0 +1,22 @@ +clean-files += unmap_tmp.o unmap_fin.o unmap.o + +ifdef CONFIG_MODE_TT + +#Always build unmap_fin.o +extra-y += unmap_fin.o +#Do dependency tracking for unmap.o (it will be always built, but won't get the tracking unless we use this). +targets += unmap.o + +#XXX: partially copied from arch/um/scripts/Makefile.rules +$(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 diff -puN arch/um/sys-i386/Makefile~uml-link-tt-mode-against-nptl arch/um/sys-i386/Makefile --- 25/arch/um/sys-i386/Makefile~uml-link-tt-mode-against-nptl 2005-06-06 21:25:16.000000000 -0700 +++ 25-akpm/arch/um/sys-i386/Makefile 2005-06-06 21:25:16.000000000 -0700 @@ -17,3 +17,5 @@ highmem.c-dir = mm module.c-dir = kernel subdir- := util + +include arch/um/scripts/Makefile.unmap diff -puN /dev/null arch/um/sys-i386/unmap.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ 25-akpm/arch/um/sys-i386/unmap.c 2005-06-06 21:25:16.000000000 -0700 @@ -0,0 +1,25 @@ +/* + * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include +#include + +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); +} diff -puN arch/um/sys-x86_64/Makefile~uml-link-tt-mode-against-nptl arch/um/sys-x86_64/Makefile --- 25/arch/um/sys-x86_64/Makefile~uml-link-tt-mode-against-nptl 2005-06-06 21:25:16.000000000 -0700 +++ 25-akpm/arch/um/sys-x86_64/Makefile 2005-06-06 21:25:16.000000000 -0700 @@ -29,3 +29,5 @@ thunk.S-dir = lib module.c-dir = kernel subdir- := util + +include arch/um/scripts/Makefile.unmap diff -puN /dev/null arch/um/sys-x86_64/unmap.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ 25-akpm/arch/um/sys-x86_64/unmap.c 2005-06-06 21:25:16.000000000 -0700 @@ -0,0 +1,25 @@ +/* + * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include +#include + +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); +} _