[3/4] gdb.trace: Use g packet order in tfile_fetch_registers.
Commit Message
tfile_fetch_registers currently wrongly fetches registers using
gdb order instead of g packet order. On x86_64 with AVX, this causes
problems with ymm*h and orig_rax registers: gdb has ymm*h first, while
g packet has orig_rax first.
gdb/ChangeLog:
* tracefile-tfile.c (tfile_fetch_registers): Use g packet order
instead of gdb order.
---
gdb/ChangeLog | 5 +++++
gdb/tracefile-tfile.c | 11 ++++++-----
2 files changed, 11 insertions(+), 5 deletions(-)
Comments
On 02/06/2016 03:39 PM, Marcin Kościelnicki wrote:
> tfile_fetch_registers currently wrongly fetches registers using
> gdb order instead of g packet order. On x86_64 with AVX, this causes
> problems with ymm*h and orig_rax registers: gdb has ymm*h first, while
> g packet has orig_rax first.
>
> gdb/ChangeLog:
>
> * tracefile-tfile.c (tfile_fetch_registers): Use g packet order
> instead of gdb order.
OK.
The docs already explicitly say that we use g packet order, though the
bit about GDB register order seems odd:
@table @code
@item R @var{bytes}
Register block. The number and ordering of bytes matches that of a
^^^^^^^^ ^^^^^^^
@code{g} packet in the remote protocol. Note that these are the
^^^^^^^^^^^^^^^
actual bytes, in target order and @value{GDBN} register order, not a
^^^^^^^^^^^^^^^^^^^^^^^^^^^
????
hexadecimal encoding.
I can't make sense of that. I think we should
s/and @value{GDBN} register order,// .
WDYT?
Thanks,
Pedro Alves
On 10/02/16 14:20, Pedro Alves wrote:
> On 02/06/2016 03:39 PM, Marcin Kościelnicki wrote:
>> tfile_fetch_registers currently wrongly fetches registers using
>> gdb order instead of g packet order. On x86_64 with AVX, this causes
>> problems with ymm*h and orig_rax registers: gdb has ymm*h first, while
>> g packet has orig_rax first.
>>
>> gdb/ChangeLog:
>>
>> * tracefile-tfile.c (tfile_fetch_registers): Use g packet order
>> instead of gdb order.
>
> OK.
>
> The docs already explicitly say that we use g packet order, though the
> bit about GDB register order seems odd:
>
> @table @code
> @item R @var{bytes}
> Register block. The number and ordering of bytes matches that of a
> ^^^^^^^^ ^^^^^^^
>
> @code{g} packet in the remote protocol. Note that these are the
> ^^^^^^^^^^^^^^^
> actual bytes, in target order and @value{GDBN} register order, not a
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> ????
>
> hexadecimal encoding.
>
>
> I can't make sense of that. I think we should
> s/and @value{GDBN} register order,// .
>
> WDYT?
>
> Thanks,
> Pedro Alves
>
Yeah, I think so. Should I add it to the patch?
On 02/10/2016 01:21 PM, Marcin Kościelnicki wrote:
>> I can't make sense of that. I think we should
>> s/and @value{GDBN} register order,// .
>>
>> WDYT?
>>
> Yeah, I think so. Should I add it to the patch?
Yes please.
Thanks,
Pedro Alves
@@ -1,5 +1,10 @@
2016-02-06 Marcin Kościelnicki <koriakin@0x04.net>
+ * tracefile-tfile.c (tfile_fetch_registers): Use g packet order
+ instead of gdb order.
+
+2016-02-06 Marcin Kościelnicki <koriakin@0x04.net>
+
* tracefile-tfile.c (trace_tdesc): New static variable.
(trace_tdesc_alloc): New static variable.
(trace_tdesc_len): New static variable.
@@ -30,6 +30,7 @@
#include "filenames.h"
#include "xml-tdesc.h"
#include "target-descriptions.h"
+#include "remote.h"
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
@@ -857,7 +858,7 @@ tfile_fetch_registers (struct target_ops *ops,
struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
- int offset, regn, regsize;
+ int offset, regn, regsize, dummy;
/* An uninitialized reg size says we're not going to be
successful at getting register blocks. */
@@ -870,11 +871,12 @@ tfile_fetch_registers (struct target_ops *ops,
tfile_read (regs, trace_regblock_size);
- /* Assume the block is laid out in GDB register number order,
- each register with the size that it has in GDB. */
- offset = 0;
for (regn = 0; regn < gdbarch_num_regs (gdbarch); regn++)
{
+ if (!remote_register_number_and_offset (get_regcache_arch (regcache),
+ regn, &dummy, &offset))
+ continue;
+
regsize = register_size (gdbarch, regn);
/* Make sure we stay within block bounds. */
if (offset + regsize >= trace_regblock_size)
@@ -891,7 +893,6 @@ tfile_fetch_registers (struct target_ops *ops,
regcache_raw_supply (regcache, regn, regs + offset);
}
}
- offset += regsize;
}
}
else