notes_201409

valgrindrr
    - /tmp/logrr
    - /proc/9830/maps

open client
-----------
struct _IICreateImageInfo at pub_core_initimg.h;
    - toolname
    - sp_at_startup, clstack_top.
    - argv, envp

struct _IIFinalizeImageInfo at pub_core_initimg.h;

valgrind_main (argc=3, argv=0xbffff614, envp=0xbffff624) 
    - vgPlain_ii_create_image() called at m_main.c:1896
        - open client executable
        - setup client stack and data segment (max stack/data-seg size.)

full stack
++++++++++
valgrind_main (argc=3, argv=0xbffff614, envp=0xbffff624) 
    vgPlain_ii_create_image (iicii=...) called at m_main.c:1896
        load_client (info=0x392c0690, client_ip=0x392c0684, client_toc=0x392c0688) called at m_initimg/initimg-linux.c:890
            vgPlain_do_exec (exe_name=0x38c980c0 "rr_testcode/std_input", info=0x392c0690) called at m_initimg/initimg-linux.c:91
                vgPlain_do_exec_inner (exe=0x38c980c0 "rr_testcode/std_input", info=0x392c0690 ) called at m_ume/main.c:280
                    vgPlain_pre_exec_check (exe_name=0x38c980c0 "rr_testcode/std_input", out_fd=0x392c0600, allow_setuid=0 '\000') called at m_ume/main.c:143
                        vgPlain_open (pathname=0x38c980c0 "rr_testcode/std_input", flags=0, mode=0) called at m_ume/main.c:77

Misc
++++
- module umc means user-mode exec


main workflow of translation
----------------------------
objects
+++++++
enum threadStatus
    - thread 在 scheduler 的狀態. ex. runnable, waiting syscall, or temporary yielding ... etc.

struct threadState
    - tid, thread_name, threadStatus, exitCode
    - threadArchState (architecture-specific state), threadOSstate (OS-specific state)
    - sig_mask, tmp_sig_mask, sig_queue, altstack (alternate signal stack)
    - client_stack_szB (client stack size), client_highest_word
    - [RR] dispatch_ctr

global var
    - struct threadState[VG_N_THREADS] VG_(threads)

- tranlation table/cache (module transtab)
    - TTEntry
    - Sector

important functon
-----------------
VG_(scheduler)
    - while( !VG_(is_exiting)(tid) ) (m_scheduler.c:1261 ~ 1607)
        - run_thread_for_a_while( &trc, ... )
        - according to trc[0]: (if && switch)
            - handle_noredir_jump
            - handle_tt_miss
            - handle_chain_me
            - do_client_request
            - handle_syscall
            - trc[0] == VG_TRC_INNER_COUNTERZERO, dispatch_ctr == 0,
                - Timeslice is out. Let a new thread be scheduled

handle_tt_miss
    - if VG_(search_transtab)
    - [false] VG_(translate)
        - VG_(add_to_transtab) called at coregrind/m_translate.c:1651

run_thread_for_a_while
----------------------
- not TT_FAST_HASH & not VG_(search_transtab)
    - two_word = VG_TRC_INNER_FASTMISS
- VG_(disp_run_translations)
    - change two_word

Return Code of Translation
++++++++++++++++++++++++++
VG_TRC_* & VEX_TRC_*

the return value is from
    1. run_thread_for_a_while
    2. VG_(disp_run_translations)

- VG_TRC_BORING             
- VEX_TRC_JMP_BORING      
    - do nothing

- VG_TRC_INNER_FASTMISS     
    - handle_tt_miss

- VG_TRC_CHAIN_ME_TO_SLOW_EP
- VG_TRC_CHAIN_ME_TO_FAST_EP
    - handle_chain_me

- VEX_TRC_JMP_NOREDIR   
    - handle_noredir_jump

- VEX_TRC_JMP_SYS_SYSCALL 
- VEX_TRC_JMP_SYS_INT32   
- VEX_TRC_JMP_SYS_INT128  
- VEX_TRC_JMP_SYS_INT129  
- VEX_TRC_JMP_SYS_INT130  
- VEX_TRC_JMP_SYS_SYSENTER
    - handle_syscall

- VEX_TRC_JMP_CLIENTREQ  
    - do_client_request

- VG_TRC_INNER_COUNTERZERO  
    - dispatch_ctr == 0

- VEX_TRC_JMP_YIELD      
    - explicit yield
    - if dispatch_ctr > 1000: dispatch_ctr = 1000

- VG_TRC_FAULT_SIGNAL       
- VEX_TRC_JMP_SIGTRAP   
- VEX_TRC_JMP_SIGSEGV   
- VEX_TRC_JMP_SIGBUS    
- VEX_TRC_JMP_SIGFPE_INTDIV 
- VEX_TRC_JMP_SIGFPE_INTOVF 

- VEX_TRC_JMP_MAPFAIL    
    - VG_(synth_fault)

- VEX_TRC_JMP_NODECODE   
    - valgrind: Unrecognised instruction

- VG_TRC_INVARIANT_FAILED   
    - bug in VEX codegen

- VEX_TRC_JMP_TINVAL    
    - invalid translation

- VEX_TRC_JMP_EMWARN     
- VEX_TRC_JMP_EMFAIL     

SCHEDSETJMP
+++++++++++
SCHEDSETJMP(tid, jumped, stmt)
do {
    ThreadState * volatile _qq_tst = VG_(get_ThreadState)(tid);
    (jumped) = VG_MINIMAL_SETJMP(_qq_tst->sched_jmpbuf);              

    if ((jumped) == ((UWord)0)) {                                     
        vg_assert(!_qq_tst->sched_jmpbuf_valid);
        _qq_tst->sched_jmpbuf_valid = True;
        stmt;
    }
    else if (VG_(clo_trace_sched))
        VG_(printf)("SCHEDSETJMP(line %d) tid %d, jumped=%ldn", __LINE__, tid, jumped);                            

    vg_assert(_qq_tst->sched_jmpbuf_valid);
    _qq_tst->sched_jmpbuf_valid = False;
} while(0)

stmt = VG_(disp_run_translations)(two_words, (void*)&tst->arch.vex, host_code_addr)