Re: [PATCH] Use ptid from regcache instead of inferior_ptid.

[John Baldwin <jhb@freebsd.org>]

On Tuesday, April 04, 2017 03:29:29 PM Simon Marchi wrote:
> On 2017-04-04 15:04, John Baldwin wrote:
> > gdb/ChangeLog:
> > 
> > 	* amd64-bsd-nat.c (amd64bsd_fetch_inferior_registers,
> > 	amd64bsd_store_inferior_registers): Use ptid from regcache.
> > ---
> >  gdb/ChangeLog       |  5 +++++
> >  gdb/amd64-bsd-nat.c | 32 ++++++++++++++------------------
> >  2 files changed, 19 insertions(+), 18 deletions(-)
> > 
> > diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> > index fc8dbe18da..259acca1ce 100644
> > --- a/gdb/ChangeLog
> > +++ b/gdb/ChangeLog
> > @@ -1,3 +1,8 @@
> > +2017-04-04  John Baldwin  <jhb@FreeBSD.org>
> > +
> > +	* amd64-bsd-nat.c (amd64bsd_fetch_inferior_registers,
> > +	amd64bsd_store_inferior_registers): Use ptid from regcache.
> > +
> >  2017-04-04  Simon Marchi  <simon.marchi@polymtl.ca>
> > 
> >  	* remote.c (set_general_thread, set_continue_thread): Use ptid_t
> > diff --git a/gdb/amd64-bsd-nat.c b/gdb/amd64-bsd-nat.c
> > index 5678e94d11..ca61a3551b 100644
> > --- a/gdb/amd64-bsd-nat.c
> > +++ b/gdb/amd64-bsd-nat.c
> > @@ -43,13 +43,13 @@ amd64bsd_fetch_inferior_registers (struct 
> > target_ops *ops,
> >  				   struct regcache *regcache, int regnum)
> >  {
> >    struct gdbarch *gdbarch = get_regcache_arch (regcache);
> > +  pid_t pid = get_ptrace_pid (regcache_get_ptid (regcache));
> > 
> >    if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, 
> > regnum))
> >      {
> >        struct reg regs;
> > 
> > -      if (ptrace (PT_GETREGS, get_ptrace_pid (inferior_ptid),
> > -		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
> > +      if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
> >  	perror_with_name (_("Couldn't get registers"));
> > 
> >        amd64_supply_native_gregset (regcache, &regs, -1);
> > @@ -66,8 +66,8 @@ amd64bsd_fetch_inferior_registers (struct target_ops 
> > *ops,
> >        if (x86bsd_xsave_len != 0)
> >  	{
> >  	  xstateregs = alloca (x86bsd_xsave_len);
> > -	  if (ptrace (PT_GETXSTATE, get_ptrace_pid (inferior_ptid),
> > -		      (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
> > +	  if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0)
> > +	      == -1)
> >  	    perror_with_name (_("Couldn't get extended state status"));
> > 
> >  	  amd64_supply_xsave (regcache, -1, xstateregs);
> > @@ -75,8 +75,7 @@ amd64bsd_fetch_inferior_registers (struct target_ops 
> > *ops,
> >  	}
> >  #endif
> > 
> > -      if (ptrace (PT_GETFPREGS, get_ptrace_pid (inferior_ptid),
> > -		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
> > +      if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == 
> > -1)
> >  	perror_with_name (_("Couldn't get floating point status"));
> > 
> >        amd64_supply_fxsave (regcache, -1, &fpregs);
> > @@ -91,19 +90,18 @@ amd64bsd_store_inferior_registers (struct 
> > target_ops *ops,
> >  				   struct regcache *regcache, int regnum)
> >  {
> >    struct gdbarch *gdbarch = get_regcache_arch (regcache);
> > +  pid_t pid = get_ptrace_pid (regcache_get_ptid (regcache));
> > 
> >    if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, 
> > regnum))
> >      {
> >        struct reg regs;
> > 
> > -      if (ptrace (PT_GETREGS, get_ptrace_pid (inferior_ptid),
> > -                  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
> > +      if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
> >          perror_with_name (_("Couldn't get registers"));
> > 
> >        amd64_collect_native_gregset (regcache, &regs, regnum);
> > 
> > -      if (ptrace (PT_SETREGS, get_ptrace_pid (inferior_ptid),
> > -	          (PTRACE_TYPE_ARG3) &regs, 0) == -1)
> > +      if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
> >          perror_with_name (_("Couldn't write registers"));
> > 
> >        if (regnum != -1)
> > @@ -119,27 +117,25 @@ amd64bsd_store_inferior_registers (struct 
> > target_ops *ops,
> >        if (x86bsd_xsave_len != 0)
> >  	{
> >  	  xstateregs = alloca (x86bsd_xsave_len);
> > -	  if (ptrace (PT_GETXSTATE, get_ptrace_pid (inferior_ptid),
> > -		      (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
> > +	  if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0)
> > +	      == -1)
> >  	    perror_with_name (_("Couldn't get extended state status"));
> > 
> >  	  amd64_collect_xsave (regcache, regnum, xstateregs, 0);
> > 
> > -	  if (ptrace (PT_SETXSTATE, get_ptrace_pid (inferior_ptid),
> > -		      (PTRACE_TYPE_ARG3) xstateregs, x86bsd_xsave_len) == -1)
> > +	  if (ptrace (PT_SETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs,
> > +		      x86bsd_xsave_len) == -1)
> >  	    perror_with_name (_("Couldn't write extended state status"));
> >  	  return;
> >  	}
> >  #endif
> > 
> > -      if (ptrace (PT_GETFPREGS, get_ptrace_pid (inferior_ptid),
> > -		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
> > +      if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == 
> > -1)
> >  	perror_with_name (_("Couldn't get floating point status"));
> > 
> >        amd64_collect_fxsave (regcache, regnum, &fpregs);
> > 
> > -      if (ptrace (PT_SETFPREGS, get_ptrace_pid (inferior_ptid),
> > -		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
> > +      if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == 
> > -1)
> >  	perror_with_name (_("Couldn't write floating point status"));
> >      }
> > 
> 
> Whoops, looks like an oversight on my part.
> 
> Thanks!

No problem.  I checked the rest of the inferior_ptid's in the *bsd*
files and they all seem sane?  The debug register stuff uses inferior_ptid,
but it also uses that on other platforms.  (And I think we don't store
debug registers in the register cache.)

-- 
John Baldwin