Re: [RFA 3/5] Prec: x86 segment register support: target

[Hui Zhu <teawater at gmail dot com>]

Prec i386 code is not OS special.  So the base will not be OS special too.

Thanks,
Hui

On Mon, Mar 22, 2010 at 22:35, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Mon, Mar 22, 2010 at 7:02 AM, Hui Zhu <teawater@gmail.com> wrote:
>> Thanks Michael and Daniel.
>>
>> I make a patch to add base of segments registers to x86-32:
>> (gdb) info reg
>> eax ? ? ? ? ? ?0xffffd514 ? ? ? -10988
>> ecx ? ? ? ? ? ?0x1eda96c5 ? ? ? 517641925
>> edx ? ? ? ? ? ?0x1 ? ? ?1
>> ebx ? ? ? ? ? ?0xf7fb1ff4 ? ? ? -134537228
>> esp ? ? ? ? ? ?0xffffd488 ? ? ? 0xffffd488
>> ebp ? ? ? ? ? ?0xffffd488 ? ? ? 0xffffd488
>> esi ? ? ? ? ? ?0x8048510 ? ? ? ?134513936
>> edi ? ? ? ? ? ?0x80483d0 ? ? ? ?134513616
>> eip ? ? ? ? ? ?0x8048487 ? ? ? ?0x8048487 <main+3>
>> eflags ? ? ? ? 0x246 ? ?[ PF ZF IF ]
>> cs ? ? ? ? ? ? 0x23 ? ? 35
>> ss ? ? ? ? ? ? 0x2b ? ? 43
>> ds ? ? ? ? ? ? 0x2b ? ? 43
>> es ? ? ? ? ? ? 0x2b ? ? 43
>> fs ? ? ? ? ? ? 0x0 ? ? ?0
>> gs ? ? ? ? ? ? 0x63 ? ? 99
>> cs_base ? ? ? ?0x0 ? ? ?0
>> ss_base ? ? ? ?0x0 ? ? ?0
>> ds_base ? ? ? ?0x0 ? ? ?0
>> es_base ? ? ? ?0x0 ? ? ?0
>> fs_base ? ? ? ?0x0 ? ? ?0
>> gs_base ? ? ? ?0xf7e528d0 ? ? ? -135976752
>>
>> I try it in x86-32 pc and 32bit code in x86-64. ?It works OK.
>>
>> Please help me review it.
>>
>> Best regards,
>> Hui
>>
>> 2010-03-22 ?Hui Zhu ?<teawater@gmail.com>
>>
>> ? ? ? ?* features/i386/32bit-linux.xml (org.gnu.gdb.i386.linux): Add
>> ? ? ? ?cs_base, ss_base, ds_base, es_base, fs_base and gs_base.
>> ? ? ? ?* i386-tdep.h (i386_segment_base_regnum): New enum.
>> ? ? ? ?* amd64-linux-nat.c (GDT_ENTRY_TLS_MIN,
>> ? ? ? ?GDT_ENTRY_TLS_MAX): New marco.
>> ? ? ? ?(ps_get_thread_area): New extern.
>> ? ? ? ?(amd64_linux_fetch_inferior_registers): Add
>> ? ? ? ?code to get 32 bits segment registers base.
>> ? ? ? ?* i386-linux-nat.c (GDT_ENTRY_TLS_ENTRIES,
>> ? ? ? ?GDT_ENTRY_TLS_MIN,
>> ? ? ? ?GDT_ENTRY_TLS_MAX): New marco.
>> ? ? ? ?(ps_get_thread_area): New extern.
>> ? ? ? ?(i386_linux_fetch_inferior_registers): Add
>> ? ? ? ?code to get segment registers base.
>
> Are we going to support them on other OSes? If not,
> the contents of i386_segment_base_regnum should be
> moved to i386-linux-tdep.h and those values should
> be after
>
> /* Register number for the "orig_eax" pseudo-register. ?If this
> ? pseudo-register contains a value >= 0 it is interpreted as the
> ? system call number that the kernel is supposed to restart. ?*/
> #define I386_LINUX_ORIG_EAX_REGNUM I386_SSE_NUM_REGS
>
> In any cases, they shouldn't be hard-coded to any values.
> Otherwise, it won't work with AVX, which will add more registers.
>
>
> --
> H.J.
>