On 12/03/2014 10:52 AM, Michael Ellerman wrote:

On Tue, 2014-02-12 at 07:56:45 UTC, Anshuman Khandual wrote:

quoted

This patch adds four new ELF core note sections for powerpc
transactional memory and one new ELF core note section for
powerpc general miscellaneous debug registers. These addition
of new ELF core note sections extends the existing ELF ABI
without affecting it in any manner.

Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Anshuman Khandual <redacted>
---
 include/uapi/linux/elf.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index ea9bf25..2260fc0 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h

@@ -379,6 +379,11 @@ typedef struct elf64_shdr {
 #define NT_PPC_VMX	0x100		/* PowerPC Altivec/VMX registers */
 #define NT_PPC_SPE	0x101		/* PowerPC SPE/EVR registers */
 #define NT_PPC_VSX	0x102		/* PowerPC VSX registers */
+#define NT_PPC_TM_SPR	0x103		/* PowerPC TM special registers */
+#define NT_PPC_TM_CGPR	0x104		/* PowerpC TM checkpointed GPR */
+#define NT_PPC_TM_CFPR	0x105		/* PowerPC TM checkpointed FPR */
+#define NT_PPC_TM_CVMX	0x106		/* PowerPC TM checkpointed VMX */
+#define NT_PPC_MISC	0x107		/* PowerPC miscellaneous registers */

This is a really terrible name, "MISC".

Having said that, I guess it's accurate. We have a whole bunch of regs that
have accrued over recent years that aren't accessible via ptrace.

It seems to me if we're adding a misc regset we should be adding everything we
might want to it that is currenty architected.

But I believe they also need to be part of the thread_struct structure to be
accessible from ptrace.
 

But currently you only include the PPR, TAR & DSCR.

Yeah, thats what we started with.

Looking at Power ISA v2.07, I see the following that could be included:

  MMCR2
  MMCRA
  PMC1
  PMC2
  PMC3
  PMC4
  PMC5
  PMC6
  MMCR0
  EBBHR
  EBBRR
  BESCR
  SIAR
  SDAR
  CFAR?

MMCRA, PMC[1..6], EBBHR, BESCR, EBBRR, CFAR are not part of the thread struct.

Those are all new in 2.07 except for CFAR.

There might be more I missed, that was just a quick scan.

Some are only accessible when EBB is in use, maybe those could be a separate
regset.

Yeah we can have one more regset for EBB specific registers.