Currently, multiple kprobe programs are suffering from symbol mismatch
due to compiler optimization. These optimizations might induce
additional suffix to the symbol name such as '.isra' or '.constprop'.
# egrep ' finish_task_switch| __netif_receive_skb_core' /proc/kallsyms
ffffffff81135e50 t finish_task_switch.isra.0
ffffffff81dd36d0 t __netif_receive_skb_core.constprop.0
ffffffff8205cc0e t finish_task_switch.isra.0.cold
ffffffff820b1aba t __netif_receive_skb_core.constprop.0.cold
To avoid this, this commit replaces the original kprobe section to
kprobe.multi in order to match symbol with wildcard characters. Here,
asterisk is used for avoiding symbol mismatch.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-5-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
/* record previous thread sleep time */
u32 pid = ctx->prev_pid;
#else
-SEC("kprobe/finish_task_switch")
+SEC("kprobe.multi/finish_task_switch*")
int oncpu(struct pt_regs *ctx)
{
struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
* Number of arguments and their positions can change, etc.
* In such case this bpf+kprobe example will no longer be meaningful
*/
-SEC("kprobe/__netif_receive_skb_core")
+SEC("kprobe.multi/__netif_receive_skb_core*")
int bpf_prog1(struct pt_regs *ctx)
{
/* attaches to kprobe __netif_receive_skb_core,
* looks for packets on loobpack device and prints them
+ * (wildcard is used for avoiding symbol mismatch due to optimization)
*/
char devname[IFNAMSIZ];
struct net_device *dev;