[Crash-utility] crash doesn't decode regs with 7.1.5

[Sagar Borikar]

Hi,

I am facing issues with crash 7.1.5 for little endian mips CPU. Crash
is not able to decode the registers. But except registers all other
information is good. I tried to look at the notes section in the core
but doesn't seem anything wrong there. If I trace the vmcore with mips
gdb I can get the correct stack trace and register info.

crash> i r
The program has no registers now.
gdb: gdb request failed: i r

crash> bt
PID: 267    TASK: 808f66d0  CPU: 0   COMMAND: "sh"


For the same vmcore, on gdb:

(gdb) i r
          zero       at       v0       v1       a0       a1       a2       a3
 R0   00000000 004b376a 00000002 00000001 000024b0 0000000a ffffffff 00000002
            t0       t1       t2       t3       t4       t5       t6       t7
 R8   808f1180 00000000 00000001 77ab8000 7fd53050 004b4580 00000000 00000000
            s0       s1       s2       s3       s4       s5       s6       s7
 R16  00000002 808f0b80 808f1180 fffffff2 80d97f10 808f0b8c 00000030 00480000
            t8       t9       k0       k1       gp       sp       s8       ra
 R24  00000002 803b05bc 0000000a 81005890 80d94000 80d97e18 00000020 803b05e0
            sr       lo       hi      bad    cause       pc
      50808000 1100fc03 00000000 00000002 803b05e0 00000000


(gdb) bt
#0  0x00000000 in ?? ()
#1  0x803b05e0 in pcieport_sysfs_store (kobj=<optimized out>,
attr=<optimized out>, data=<optimized out>, len=<optimized out>) at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/drivers/cisco/pcieport/sysfs.c:59
#2  0x8021c6bc in kernfs_fop_write (file=<optimized out>,
user_buf=<optimized out>, count=<optimized out>, ppos=0x80d97f10) at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/fs/kernfs/file.c:312
#3  0x801c9020 in __vfs_write (file=0x24b0, p=<optimized out>,
count=<optimized out>, pos=<optimized out>) at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/fs/read_write.c:489
#4  0x801c9eac in vfs_write (file=0x83b187c0, buf=0xa <Address 0xa out
of bounds>, count=<optimized out>, pos=0x80d97f10) at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/fs/read_write.c:538
#5  0x801ca0dc in SYSC_write (count=<optimized out>, buf=<optimized
out>, fd=<optimized out>) at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/fs/read_write.c:585
#6  SyS_write (fd=<optimized out>, buf=<optimized out>,
count=<optimized out>) at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/fs/read_write.c:578
#7  0x8010e1dc in syscall_common () at
/build/sborikar/bodegadev/bodega-dev/mcpu/firmware/linux-4.4/arch/mips/kernel/scall32-o32.S:102

Any idea?

Thanks
Sagar