Re: [Crash-utility] getting values of local variable
----- Original Message -----
How can i get the value of a structure variable used in a kernel
module.The
structure is private to the module. Using struct command did not yield any
result as the structure type is unknown to crash. Thanks.
--
Vivek Anand T Kallampally
Have you loaded the debuginfo data of the kernel module into the crash session?
For example, in the "fs/nfs/mount_clnt.c" kernel module there is this
declaration:
static struct rpc_stat mnt_stats;
Without loading the debuginfo data of the "nfs" module, there is only minimal
information available about the data structure instance, namely just its virtual
address, its section, and the module that it's contained within:
crash> sym mnt_stats
ffffffffa086bca0 (b) mnt_stats [nfs]
crash> p mnt_stats
p: gdb request failed: p mnt_stats
crash> whatis mnt_stats
whatis: gdb request failed: whatis mnt_stats
crash>
Loading the debuginfo data of the module (usually) brings in the additional
information into the crash session:
crash> mod -s nfs
MODULE NAME SIZE OBJECT FILE
ffffffffa086b920 nfs 169344
/lib/modules/3.9.10-100.fc17.x86_64/kernel/fs/nfs/nfs.ko
crash> whatis mnt_stats
struct rpc_stat mnt_stats;
crash> p mnt_stats
mnt_stats = $2 = {
program = 0x0,
netcnt = 0,
netudpcnt = 0,
nettcpcnt = 0,
nettcpconn = 0,
netreconn = 3,
rpccnt = 6,
rpcretrans = 0,
rpcauthrefresh = 6,
rpcgarbage = 0
}
crash>
Dave