Re: [PATCH 0/3] Add new ptrace request macros on PowerPC
From: Anshuman Khandual <hidden>
Date: 2014-04-02 09:34:10
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lkml
On 04/02/2014 12:32 PM, Anshuman Khandual wrote:
This patch series adds new ELF note sections which are used to create new ptrace request macros for various transactional memory and miscellaneous registers on PowerPC. Please find the test case exploiting the new ptrace request macros and it's results on a POWER8 system. RFC: https://lkml.org/lkml/2014/4/1/292 ============================== Results ============================== -------TM specific SPR------ TM TFHAR: 100009dc TM TEXASR: de000001ac000001 TM TFIAR: c00000000003f386 TM CH ORIG_MSR: 900000050000f032 TM CH TAR: 6 TM CH PPR: c000000000000 TM CH DSCR: 1 -------TM checkpointed GPR----- TM CH GPR[0]: 1000097c TM CH GPR[1]: 5 TM CH GPR[2]: 6 TM CH GPR[7]: 1 TM CH NIP: 100009dc TM CH LINK: 1000097c TM CH CCR: 22000422 -------TM running GPR----- TM RN GPR[0]: 1000097c TM RN GPR[1]: 7 TM RN GPR[2]: 8 TM RN GPR[7]: 5 TM RN NIP: 100009fc TM RN LINK: 1000097c TM RN CCR: 2000422 -------TM running FPR----- TM RN FPR[0]: 1002d3a3780 TM RN FPR[1]: 7 TM RN FPR[2]: 8 TM RN FPSCR: 0 -------TM checkpointed FPR----- TM CH FPR[0]: 1002d3a3780 TM CH FPR[1]: 5 TM CH FPR[2]: 6 TM CH FPSCR: 0 -------Running miscellaneous registers-------
TM RN DSCR: 0 There is a problem in here which I forgot to mention. The running DSCR value comes from thread->dscr component of the target process. While we are inside the transaction (which is the case here as we are stuck at "b ." instruction and have not reached TEND) thread->dscr should have the running value of the DSCR register at that point of time. Here we expect the DSCR value to be 5 instead of 0 as shown in the output above. During the tests when I moved the "b ." after TEND, the thread->dscr gets the value of 5 while all check pointed reg values are thrown away. I believe there is some problem in the way thread->dscr context is saved away inside the TM section. Will look into this problem further and keep informed.