[Kgdb-bugreport] CFI macros for PXA270

[Girish S. <gi...@li...>]

Hi,
I am facing a problem while printing backtrace for kgdb.
I am using:
GDB: gdb-6.4
Kernel: 2.6.15
Processor: PXA270

Even though cfi macros have been added just before call to asm_do_IRQ in
arch/arm/kernel/entry-armv.S.
The backtrace doesn't traverse beyond __irq_svc

gdb) bt
#0  0xc0052814 in $d () at kernel/kgdb.c:1880
#1  0xc005284c in kgdb_tasklet_bpt (ing=0) at kernel/kgdb.c:1752
#2  0xc003a5e8 in tasklet_action (a=0x0) at kernel/softirq.c:267
#3  0xc003a1c8 in __do_softirq () at kernel/softirq.c:95
#4  0xc003a350 in irq_exit () at kernel/softirq.c:169
#5  0xc0020d0c in asm_do_IRQ (irq=1, regs=0xc01e9f58)
    at arch/arm/kernel/irq.c:560
#6  0xc001f9a4 in __irq_svc () at proc_fs.h:188
(gdb)


CFI macro added to entry-armv.S
--------------------------------------------------------------------------
       .macro  irq_handler
1:      get_irqnr_and_base r0, r6, r5, lr
        movne   r1, sp
        @
        @ routine called with r0 = irq number, r1 = struct pt_regs *
        @
        adrne   lr, 1b
        .cfi_def_cfa r13, 72

        /* Debug information for the registers */
        .cfi_offset r0,    72
        .cfi_offset r1,    68
        .cfi_offset r2,    64
        .cfi_offset r3,    60
        .cfi_offset r4,    56
        .cfi_offset r5,    52
        .cfi_offset r6,    48
        .cfi_offset r7,    44
        .cfi_offset r8,    40
        .cfi_offset r9,    36
        .cfi_offset r10,   32
        .cfi_offset fp,    28
        .cfi_offset ip,    24
        .cfi_offset sp,    20
        .cfi_offset pc,    16
        bne     asm_do_IRQ
---------------------------------------------------------------------------


One more thing, from frame 5 one can see that the call is been made from
code at 0xc001f9a0 as saved pc is at 0xc001f9a4.
-----------------------------------------------------------------
(gdb) info fr 5
Stack frame at 0xc01e9f58:
pc = 0xc0020d0c in asm_do_IRQ (arch/arm/kernel/irq.c:560); saved pc
0xc001f9a4
called by frame at 0x0, caller of frame at 0xc01e9f28
source language c.
Arglist at 0xc01e9f54, args: irq=1, regs=0xc01e9f58
Locals at 0xc01e9f54, Previous frame's sp at 0xc01e9f4c
Saved registers:
  r4 at 0xc01e9f30, r5 at 0xc01e9f34, r6 at 0xc01e9f38, r7 at
0xc01e9f3c,
  r8 at 0xc01e9f40, r10 at 0xc01e9f44, r11 at 0xc01e9f48, lr at
0xc01e9f50,
  pc at 0xc01e9f50
(gdb) 
-------------------------------------------------------------


Shouldn't the call be made from 0xc001f9cc instead of 0xc001f9a0. Or am
I missing something.

0xc001f998 <__irq_svc+24>:      str     r1, [sp]
0xc001f99c <__irq_svc+28>:      mov     r1, lr
0xc001f9a0 <__irq_svc+32>:      stmia   r5, {r0, r1, r2, r3, r4}
0xc001f9a4 <__irq_svc+36>:      mrc     6, 0, r6, cr0, cr0, {0}
0xc001f9a8 <__irq_svc+40>:      mrc     6, 0, r0, cr1, cr0, {0}
0xc001f9ac <__irq_svc+44>:      ands    r0, r6, r0
0xc001f9b0 <__irq_svc+48>:      beq     0xc001f9c4 <__irq_svc+68>
0xc001f9b4 <__irq_svc+52>:      rsb     r6, r0, #0      ; 0x0
0xc001f9b8 <__irq_svc+56>:      and     r6, r6, r0
0xc001f9bc <__irq_svc+60>:      clz     r0, r6
0xc001f9c0 <__irq_svc+64>:      rsb     r0, r0, #31     ; 0x1f
0xc001f9c4 <__irq_svc+68>:      movne   r1, sp
0xc001f9c8 <__irq_svc+72>:      subne   lr, pc, #44     ; 0x2c
0xc001f9cc <__irq_svc+76>:      bne     0xc0020c04 <asm_do_IRQ>

Kindly let me know where I should look, for solving this problem.

Thanks in advance.

Regards,
-Girish.