[#4557] hardware breakpoint doesn't always work in kgdb

Submitted By: Mingquan Pan

Open Date

2008-10-21 04:26:51 Close Date

2008-12-03 03:52:08

Priority:

Medium Assignee:

Sonic Zhang

Status:

Closed Fixed In Release:

N/A

Found In Release:

N/A Release:

Category:

N/A Board:

N/A

Processor:

N/A Silicon Revision:

Is this bug repeatable?:

Yes Resolution:

Fixed

Uboot version or rev.:

Toolchain version or rev.:

Oct 10

App binary format:

N/A

Summary: hardware breakpoint doesn't always work in kgdb

Details:

hardware breakpoint doesn't always work in kgdb on trunk. It works at the first two times, but if you repeatedly trigger that hardware breakpoint, it would slip over that point once in two times.

(gdb) target remote udp:10.100.4.50:6443

A program is being debugged already. Kill it? (y or n) y

Remote debugging using udp:10.100.4.50:6443

kgdb_breakpoint () at kernel/kgdb.c:1675

1675 atomic_set(&kgdb_setting_breakpoint, 0);

(gdb) hb kgdb_test

Hardware assisted breakpoint 1 at 0x92ae: file arch/blackfin/kernel/kgdb_test.c, line 70.

(gdb) info b

Num Type Disp Enb Address What

1 hw breakpoint keep y 0x000092ae in kgdb_test at arch/blackfin/kernel/kgdb_test.c:70

(gdb) c

Continuing.

[New Thread 152]

[Switching to Thread 152]

Breakpoint 1, kgdb_test (name=<value optimized out>, len=<value optimized out>, count=<value optimized out>, z=16) at arch/blackfin/kernel/kgdb_test.c:70

warning: Source file is more recent than executable.

70 {

(gdb) c

Continuing.

On target:

## Starting application at 0x001982c0 ...

Linux version 2.6.26.5-ADI-2009R1-pre-svn5460-dirty (test@my-local-machine) (gcc version 4.1.2 (ADI svn)) #39 Tue Oct 21 15:31:02 CST 2008

Warning: limiting memory to 56MB due to hardware anomaly 05000263

Board Memory: 64MB

Kernel Managed Memory: 64MB

Memory map:

fixedcode = 0x00000400-0x00000490

text = 0x00001000-0x001110d0

rodata = 0x001110e0-0x00165394

bss = 0x001653a0-0x00179384

data = 0x00179384-0x0018a000

stack = 0x00188000-0x0018a000

init = 0x0018a000-0x005aa000

available = 0x005aa000-0x037ff000

DMA Zone = 0x03f00000-0x04000000

Hardware Trace Active and Enabled

Reset caused by Software reset

Compiled for ADSP-BF537 Rev 0.2

Blackfin Linux support by blackfin.uclinux.org/

Processor Speed: 500 MHz core clock and 100 MHz System Clock

NOMPU: setting up cplb tables for global access

Instruction Cache Enabled

Data Cache Enabled (write-through)

Built 1 zonelists in Zone order, mobility grouping off. Total pages: 14223

Kernel command line: console=ttyBF0,57600 kgdboe=@10.100.4.50/,@10.100.4.174/

kgdboe: local port 6443

kgdboe: local IP 10.100.4.50

kgdboe: interface eth0

kgdboe: remote port 6442

kgdboe: remote IP 10.100.4.174

kgdboe: remote ethernet address ff:ff:ff:ff:ff:ff

Configuring Blackfin Priority Driven Interrupts

PID hash table entries: 256 (order: 8, 1024 bytes)

console [ttyBF0] enabled

...

root:/> cat /proc/kgdbtest

kgdb name(12): hello world!, 85, 16

L1 : code function addr = 0xffa0039c

, data variable addr = 0xff800010, data value is 0

root:/> cat /proc/kgdbtest

Follow-ups

--- Sonic Zhang 2008-11-10 03:36:31

Fixed.

--- Mingquan Pan 2008-12-03 03:52:08

Yes,close.

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