On Wednesday 08 June 2005 19:38, Nix wrote:
> On Wed, 8 Jun 2005, [EMAIL PROTECTED] said:
> > On Tuesday 07 June 2005 21:47, Nix wrote:
> >> On Tue, 7 Jun 2005, [EMAIL PROTECTED] suggested tentatively:
> >> > On Tuesday 07 June 2005 18:21, Nix wrote:
> >> >> OK, so it's a -static TT build that's failing?
> >> >
> >> > Exactly.
> >>
> >> Built, with a randomly selected .config (that is, a .config I use for
> >> other things, not a .config with the values set at random!)
> >
> > Hmm, broken-out in the archives works perfectly (with patch-scripts). Go
> > until uml-link-tt-mode-against-nptl.patch and retry, and possibly even
> > with the previous one... please.
>
> OK, will do.
>
> >> With that applied, it builds...
> >>
> >> ... and segfaults almost at once on invocation:
> >>
> >> execve("./vmlinux", ["./vmlinux"], [/* 49 vars */]) = 0
> >> uname({sys="Linux", node="hades", ...}) = 0
> >> brk(0) = 0xa0343000
> >> brk(0xa0343834) = 0xa0343834
> >> set_thread_area({entry_number:-1 -> 6, base_addr:0xa034381c,
> >> limit:1048575, seg_32bit:1, contents:0, read_exec_only:0,
> >> limit_in_pages:1,
> >> seg_not_present:0, useable:1}) = 0 --- SIGSEGV (Segmentation fault) @ 0
> >> (0)
> >
> > Hmm, gdb would be more helpful... I was getting a SIGBUS somewhere on
> > x86_64 (with a native binary) here, and maybe it could be the same thing
> > (no, it can't, your error is different, so I'm talking to myself):
>
> Unlikely: this isn't an x86-64 box ;}
No, I thought it was a general error...
> > And here is the memory map... whoops! The code is trying to read from
> > 60c00000, which is mapped... but from an absurd address! And from a
> > different file from all the rest!
> [snip]
>
> > 60c00000-a2000000 rwxs ffffffffc0c00000 00:0e
> > 1383102 /tmp/vm_file-JmW1nY (deleted)
> Whaa?
Yes, strange offset... it's what I noted too.
> >> Looks like a thread initialization problem to *me*. And there be very
> >> serious and nasty snarling dragons with sharp pointy carborundum teeth
> > This kind of problems is normally caused from wrong alignments in the
> > linker script.
> I'm not surprised it dies: even ld can see that something's wrong. With
> V=1 we see this:
> gcc -static -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc -o
> vmlinux -Wl,-T,arch/um/kernel/vmlinux.lds init/built-in.o
> -Wl,--start-group usr/built-in.o arch/um/kernel/built-in.o
> arch/um/drivers/built-in.o arch/um/os-Linux/built-in.o
> arch/um/sys-i386/built-in.o arch/i386/crypto/built-in.o kernel/built-in.o
> mm/built-in.o fs/built-in.o ipc/built-in.o security/built-in.o
> crypto/built-in.o lib/lib.a lib/built-in.o drivers/built-in.o
> sound/built-in.o net/built-in.o -Wl,--end-group -lutil .tmp_kallsyms3.o ;
> rm -f linux /usr/bin/ld: BFD 2.16.90.0.3 20050510 assertion fail elf.c:3833
Only with V=1 the error is shown? Strange! Also, why the hell is this
assertion failing, in normal words? Is he complaining for the (now
missing) .thread_private section?
Also, would you be able to fix problems like "allocated 5 headers, needed 6"
or such? What are the criteria for choosing how many headers to allocate?
> which is the assertion here, inside
> bfd/elf.c:map_sections_to_segments():
>
> /* If there are any SHF_TLS output sections, add PT_TLS segment. */
> if (tls_count > 0)
> {
> int i;
>
> amt = sizeof (struct elf_segment_map);
> amt += (tls_count - 1) * sizeof (asection *);
> m = bfd_zalloc (abfd, amt);
> if (m == NULL)
> goto error_return;
> m->next = NULL;
> m->p_type = PT_TLS;
> m->count = tls_count;
> /* Mandated PF_R. */
> m->p_flags = PF_R;
> m->p_flags_valid = 1;
> for (i = 0; i < tls_count; ++i)
> {
> BFD_ASSERT (first_tls->flags & SEC_THREAD_LOCAL);
> m->sections[i] = first_tls;
> first_tls = first_tls->next;
> }
>
> *pm = m;
> pm = &m->next;
> }
> > Btw, I forgot that broken-out is in perfect state and would help more for
> > debug...
>
> I'll try that next.
Here I've attached the patch that today worked for me; it replaces the one
with the same name, and I applied until it.
Please, take care that there is no dependency yet from unmap_fin.o to vmlinux,
so modifying that file won't show up in the final result unless you either
tocuh arch/um/kernel/vmlinux.lds or (untested) rm .tmp_vmlinux1.
> > Global warming, isn't it? However don't worry, the Gulf Current is going
> > to stop so you'll get refreshed of -10 degrees...
> Excellent. Bring back the ice age!
> (Hm. My house wouldn't stand up well under a kilometre of ice...)
Everybody gets a free new house! Global warming is the next killer application
for house building!
--
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade
From: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]>, Al Viro <[EMAIL PROTECTED]>
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 <[EMAIL PROTECTED]>
---
linux-2.6.git-paolo/arch/um/Makefile | 2 -
linux-2.6.git-paolo/arch/um/kernel/tt/Makefile | 15 ----------
linux-2.6.git-paolo/arch/um/kernel/uml.lds.S | 15 ++--------
linux-2.6.git-paolo/arch/um/scripts/Makefile.rules | 6 ++++
linux-2.6.git-paolo/arch/um/scripts/Makefile.unmap | 22 ++++++++++++++
linux-2.6.git-paolo/arch/um/sys-i386/Makefile | 2 +
linux-2.6.git-paolo/arch/um/sys-i386/unmap.c | 25 ++++++++++++++++
linux-2.6.git-paolo/arch/um/sys-x86_64/Makefile | 2 +
linux-2.6.git-paolo/arch/um/sys-x86_64/unmap.c | 25 ++++++++++++++++
linux-2.6.git/arch/um/kernel/tt/unmap.c | 31 ---------------------
10 files changed, 86 insertions(+), 59 deletions(-)
diff -L arch/um/kernel/tt/unmap.c -puN arch/um/kernel/tt/unmap.c~uml-link-tt-mode-against-nptl /dev/null
--- linux-2.6.git/arch/um/kernel/tt/unmap.c
+++ /dev/null 2005-03-04 21:12:55.000000000 +0100
@@ -1,31 +0,0 @@
-/*
- * Copyright (C) 2000 Jeff Dike ([EMAIL PROTECTED])
- * 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:
- */
diff -puN arch/um/kernel/uml.lds.S~uml-link-tt-mode-against-nptl arch/um/kernel/uml.lds.S
--- linux-2.6.git/arch/um/kernel/uml.lds.S~uml-link-tt-mode-against-nptl 2005-06-07 19:10:51.000000000 +0200
+++ linux-2.6.git-paolo/arch/um/kernel/uml.lds.S 2005-06-07 19:10:51.000000000 +0200
@@ -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 /dev/null arch/um/sys-i386/unmap.c
--- /dev/null 2005-03-04 21:12:55.000000000 +0100
+++ linux-2.6.git-paolo/arch/um/sys-i386/unmap.c 2005-06-07 19:10:51.000000000 +0200
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike ([EMAIL PROTECTED])
+ * 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);
+}
diff -puN /dev/null arch/um/sys-x86_64/unmap.c
--- /dev/null 2005-03-04 21:12:55.000000000 +0100
+++ linux-2.6.git-paolo/arch/um/sys-x86_64/unmap.c 2005-06-07 19:10:51.000000000 +0200
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike ([EMAIL PROTECTED])
+ * 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);
+}
diff -puN arch/um/kernel/tt/Makefile~uml-link-tt-mode-against-nptl arch/um/kernel/tt/Makefile
--- linux-2.6.git/arch/um/kernel/tt/Makefile~uml-link-tt-mode-against-nptl 2005-06-07 19:10:51.000000000 +0200
+++ linux-2.6.git-paolo/arch/um/kernel/tt/Makefile 2005-06-07 19:10:51.000000000 +0200
@@ -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 $@ -G switcheroo
-
diff -puN arch/um/sys-i386/Makefile~uml-link-tt-mode-against-nptl arch/um/sys-i386/Makefile
--- linux-2.6.git/arch/um/sys-i386/Makefile~uml-link-tt-mode-against-nptl 2005-06-07 19:10:51.000000000 +0200
+++ linux-2.6.git-paolo/arch/um/sys-i386/Makefile 2005-06-07 19:10:51.000000000 +0200
@@ -15,3 +15,5 @@ bitops.c-dir = lib
semaphore.c-dir = kernel
highmem.c-dir = mm
module.c-dir = kernel
+
+include arch/um/scripts/Makefile.unmap
diff -puN arch/um/sys-x86_64/Makefile~uml-link-tt-mode-against-nptl arch/um/sys-x86_64/Makefile
--- linux-2.6.git/arch/um/sys-x86_64/Makefile~uml-link-tt-mode-against-nptl 2005-06-07 19:10:51.000000000 +0200
+++ linux-2.6.git-paolo/arch/um/sys-x86_64/Makefile 2005-06-07 19:10:51.000000000 +0200
@@ -29,3 +29,5 @@ thunk.S-dir = lib
module.c-dir = kernel
subdir- := util
+
+include arch/um/scripts/Makefile.unmap
diff -puN /dev/null arch/um/scripts/Makefile.unmap
--- /dev/null 2005-03-04 21:12:55.000000000 +0100
+++ linux-2.6.git-paolo/arch/um/scripts/Makefile.unmap 2005-06-07 19:10:51.000000000 +0200
@@ -0,0 +1,22 @@
+clean-files += unmap_tmp.o unmap_fin.o unmap.o
+
+ifdef CONFIG_MODE_TT
+
+#Always build unmap_fin.o
+extra-y += unmap_fin.o
+#Do dependency tracking for unmap.o (it will be always built, but won't get the tracking unless we use this).
+targets += unmap.o
+
+#XXX: partially copied from arch/um/scripts/Makefile.rules
+$(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/Makefile~uml-link-tt-mode-against-nptl arch/um/Makefile
--- linux-2.6.git/arch/um/Makefile~uml-link-tt-mode-against-nptl 2005-06-07 19:10:51.000000000 +0200
+++ linux-2.6.git-paolo/arch/um/Makefile 2005-06-07 19:10:51.000000000 +0200
@@ -118,7 +118,7 @@ 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
--- linux-2.6.git/arch/um/scripts/Makefile.rules~uml-link-tt-mode-against-nptl 2005-06-07 19:10:51.000000000 +0200
+++ linux-2.6.git-paolo/arch/um/scripts/Makefile.rules 2005-06-07 19:10:51.000000000 +0200
@@ -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 $@) $@
_
