[U-Boot] [PATCH 1/6] dlmalloc: ensure gd is set for early alloc

[Rabin Vincent <rabin@rab.in>]

On Sat, Nov 01, 2014 at 09:11:34AM -0600, Simon Glass wrote:
> On 29 October 2014 16:21, Rabin Vincent <rabin@rab.in> wrote:
> > Attempting to run the sandbox leads to a segfault, because some dynamic
> > libraries (outside of u-boot) attempt to use malloc() to allocate memory
> > before u-boot's gd variable is initialized.
> >
> > Check for gd not being NULL in the SYS_MALLOC_F_LEN handling, so that
> > malloc() doesn't crash when called at this point.
> >
> >  $ gdb -q --args ./u-boot
> >  (gdb) r
> >  Program received signal SIGSEGV, Segmentation fault.
> >  0x0000000000412b9b in malloc (bytes=bytes at entry=37) at common/dlmalloc.c:2184
> >  2184           if (!(gd->flags & GD_FLG_RELOC)) {
> >  (gdb) p gd
> >  $1 = (gd_t *) 0x0
> >  (gdb) bt
> >  #0  0x0000000000412b9b in malloc (bytes=bytes at entry=37) at common/dlmalloc.c:2184
> >  #1  0x00007ffff75bf8e1 in set_binding_values (domainname=0x7ffff11f4f12 "libgpg-error", dirnamep=0x7fffffffe168, codesetp=0x0)
> >      at bindtextdom.c:228
> >  #2  0x00007ffff75bfb4c in set_binding_values (codesetp=0x0, dirnamep=0x7fffffffe168, domainname=<optimized out>) at bindtextdom.c:350
> >  #3  __bindtextdomain (domainname=<optimized out>, dirname=0x7ffff11f4f00 "/usr/share/locale") at bindtextdom.c:348
> >  #4  0x00007ffff11eca17 in ?? () from /lib/x86_64-linux-gnu/libgpg-error.so.0
> >  #5  0x00007ffff7dea9fa in call_init (l=<optimized out>, argc=argc at entry=1, argv=argv at entry=0x7fffffffe208,
> >      env=env at entry=0x7fffffffe218) at dl-init.c:78
> >  #6  0x00007ffff7deaae3 in call_init (env=0x7fffffffe218, argv=0x7fffffffe208, argc=1, l=<optimized out>) at dl-init.c:36
> >  #7  _dl_init (main_map=0x7ffff7ffe1a8, argc=1, argv=0x7fffffffe208, env=0x7fffffffe218) at dl-init.c:126
> >  #8  0x00007ffff7ddd1ca in _dl_start_user () from /lib64/ld-linux-x86-64.so.2
> 
> How do you provoke this error? It doesn't seem to happen for me.

I just run the u-boot binary, which I built with sandbox_defconfig.
Perhaps you have different library versions on your system? (I see it's
libgpg-error.so which is triggering the malloc() here.)  I run Debian
unstable.