Re: [rfc] bi-arch for x86-64 corefile.

[Yao Qi <yao at codesourcery dot com>]

On 10/30/2012 08:21 AM, H.J. Lu wrote:
> > diff --git a/bfd/configure.in b/bfd/configure.in
> > >index 530bbcb..5ed3ac2 100644
> > >--- a/bfd/configure.in
> > >+++ b/bfd/configure.in
> > >@@ -331,6 +331,9 @@ changequote(,)dnl
> > >  changequote([,])dnl
> > >         COREFILE=trad-core.lo
> > >         TRAD_HEADER='"hosts/i386linux.h"'
> > >+       if test x${want64} = xtrue ; then
> > >+       CORE_HEADER='"hosts/x86-64linux.h"'
> > >+       fi
> > >         ;;
> Please use "else" for CORE_HEADER=.

H.J, thanks for the review.  A few questions below,

I don't see the point of using "else" here, am I missing something here?

> > >+    int pr_fpvalid;                    /* True if math copro being used.  */
> > >+#if __WORDSIZE == 32
> > >+    char pad[4];
> > >+#endif
> > >+  };
> This is wrong. There should be no pad.  Please properly copy the
> 64-bit elf_prstatus.

Without this pad, the size of 'struct elf_prstatus64' on 32-bit(332) is 
not equal to the size of 'struct elf_prstatus' on 64-bit(336).  IIUC, 
the goal of defining 'elf_prstatus64' is to emulate 64-bit 
'elf_prstatus' on 32-bit machine.  The field 'pad' is for tail padding, 
as the size of this struct should be multiple of 8.

> > >  struct elf_prpsinfo32
> > >    {
> > >      char pr_state;                     /* Numeric process state.  */
> > >@@ -179,6 +208,24 @@ struct elf_prpsinfo32
> > >      char pr_psargs[ELF_PRARGSZ];       /* Initial part of arg list.  */
> > >    };
> > >
> > >+struct elf_prpsinfo64
> > >+  {
> > >+    char pr_state;                     /* Numeric process state.  */
> > >+    char pr_sname;                     /* Char for pr_state.  */
> > >+    char pr_zomb;                      /* Zombie.  */
> > >+    char pr_nice;                      /* Nice val.  */
> > >+#if __WORDSIZE == 32
> > >+    char pad[4];
> > >+#endif
> > >+    uint64_t pr_flag;          /* Flags.  */
> > >+    unsigned int pr_uid;
> > >+    unsigned int pr_gid;
> > >+    int pr_pid, pr_ppid, pr_pgrp, pr_sid;
> > >+    /* Lots missing */
> > >+    char pr_fname[16];                 /* Filename of executable.  */
> > >+    char pr_psargs[ELF_PRARGSZ];       /* Initial part of arg list.  */
> > >+  };
> > >+
> This is wrong. There should be no pad.  Please properly copy the
> 64-bit elf_prpsinfo64.
Likewise, this field 'pad' is for internal padding, as field 'pr_flag' 
is 8-byte aligned.

--
Yao