[PATCH] xmon command for symbol lookups

[Benjamin Herrenschmidt]

On Wed, 2004-02-25 at 07:35, Olof Johansson wrote:
> One of the most crippling drawbacks (for me) with xmon is that you need
> a System.map to lookup all addresses in when you're digging through
> disassembly.
>
> The attached patch adds a new command, "n <address>" that will show the
> corresponding symbol in the same way that the "t" command does.
>
> It also fixes another thing that's irritated me before: xmon doesn't
> take values in 0x<hex> form, only <hex>.

Hrm... well... I have this on ppc32 already, but used different
commmands: la and ls (lookup address and lookup symbol), also I
have added the ability to use a symbol (preceded by the $) every
time you can enter a number (like you can use % with a register
name). What about making xmon in sync ? :)

Another _real cool_ feature is a dmesg in xmon btw :)



> 3:mon> t
> c00000007e4978b0  c00000000004d894  .xmon+0x15c/0x358
> c00000007e497a90  c00000000004d2e0  .sysrq_handle_xmon+0x5c/0x64
> c00000007e497b20  c00000000024d7c4  .__handle_sysrq_nolock+0xe0/0x184
> c00000007e497bd0  c00000000024d6c0  .handle_sysrq+0x70/0x94
> c00000007e497c60  c000000000102dd0  .write_sysrq_trigger+0x88/0xac
> c00000007e497cf0  c0000000000b4464  .vfs_write+0x10c/0x164
> c00000007e497d90  c0000000000b45a0  .sys_write+0x50/0x94
> c00000007e497e30  c0000000000119bc  ret_from_syscall_1
> exception: c00 (System Call) regs c00000007e497ea0
>                    000000000ff27b2c
> <Stack drops into userspace 00000000ffffe780>
> 3:mon> di c00000000024d6c0
> c00000000024d6c0  60000000      nop
> c00000000024d6c4  38210090      addi    r1,r1,144
> c00000000024d6c8  e8010010      ld      r0,16(r1)
> c00000000024d6cc  ebe1fff8      ld      r31,-8(r1)
> c00000000024d6d0  eb81ffe0      ld      r28,-32(r1)
> c00000000024d6d4  eba1ffe8      ld      r29,-24(r1)
> c00000000024d6d8  ebc1fff0      ld      r30,-16(r1)
> c00000000024d6dc  7c0803a6      mtlr    r0
> c00000000024d6e0  4bfffeac      b       0xc00000000024d58c
> c00000000024d6e4  fbc1fff0      std     r30,-16(r1)
> c00000000024d6e8  ebc2c5d8      ld      r30,-14888(r2)
> c00000000024d6ec  7c0802a6      mflr    r0
> c00000000024d6f0  fb41ffd0      std     r26,-48(r1)
> c00000000024d6f4  fb61ffd8      std     r27,-40(r1)
> c00000000024d6f8  7cba2b78      mr      r26,r5
> c00000000024d6fc  7c9b2378      mr      r27,r4
> 3:mon> n 0xc00000000024d58c
> c00000000024d58c: .__sysrq_unlock_table+0x0/0x30
> 3:mon>
>
>
>
>
>
> Another enhancement would be to simply print the symbol as a comment
> behind the address when doing disasm, but that would make the output
> wider than 80 characters. Does anyone have problems with that or should
> I add that as well?
>
>
> Thanks,
>
> Olof
>
> --
> Olof Johansson                                        Office: 4F005/905
> pSeries Linux Development                             IBM Systems Group
> Email: olof at austin.ibm.com                          Phone: 512-838-9858
> All opinions are my own and not those of IBM
>
> ______________________________________________________________________
> ===== arch/ppc64/xmon/xmon.c 1.35 vs edited =====
> --- 1.35/arch/ppc64/xmon/xmon.c	Sun Feb 15 15:23:37 2004
> +++ edited/arch/ppc64/xmon/xmon.c	Tue Feb 24 14:25:34 2004
> @@ -83,6 +83,7 @@
>  static void dump(void);
>  static void prdump(unsigned long, long);
>  static int ppc_inst_dump(unsigned long, long);
> +static void lookupsymbol(void);
>  void print_address(unsigned long);
>  static int getsp(void);
>  static void backtrace(struct pt_regs *);
> @@ -167,6 +168,7 @@
>    ml	locate a block of memory\n\
>    mz	zero a block of memory\n\
>    mi	show information about memory allocation\n\
> +  n     lookup address -> symbol name\n\
>    p 	show the task list\n\
>    r	print registers\n\
>    s	single step\n\
> @@ -537,6 +539,9 @@
>  		case 'd':
>  			dump();
>  			break;
> +		case 'n':
> +			lookupsymbol();
> +			break;
>  		case 'r':
>  			if (excp != NULL)
>  				prregs(excp);	/* print regs */
> @@ -1644,6 +1649,23 @@
>  	printf("0x%lx", addr);
>  }
>
> +
> +void
> +lookupsymbol(void)
> +{
> +	int c;
> +
> +	c = inchar();
> +	if (c == '\n')
> +		termch = c;
> +	scanhex((void *)&adrs);
> +	if( termch != '\n')
> +		termch = 0;
> +	printf("%016lx: ", adrs);
> +	xmon_print_symbol("%s\n", adrs);
> +}
> +
> +
>  /*
>   * Memory operations - move, set, print differences
>   */
> @@ -1820,6 +1842,14 @@
>  		}
>  		printf("invalid register name '%%%s'\n", regname);
>  		return 0;
> +	}
> +
> +	/* skip leading "0x" if any */
> +
> +	if (c == '0') {
> +		c = inchar();
> +		if (c == 'x')
> +			c = inchar();
>  	}
>
>  	d = hexdigit(c);
--
Benjamin Herrenschmidt <benh at kernel.crashing.org>


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