The ::findleaks dcmd provides powerful and efficient detection of memory leaks in kernel crash dumps where the full set of kmem debug features has been enabled. The first execution of ::findleaks processes the dump for memory leaks (this can take a few minutes), and then coalesces the leaks by the allocation stack trace. The findleaks report shows a bufctl address and the topmost stack frame for each memory leak that was identified:
> ::findleaks CACHE LEAKED BUFCTL CALLER 70039ba8 1 703746c0 pm_autoconfig+0x708 70039ba8 1 703748a0 pm_autoconfig+0x708 7003a028 1 70d3b1a0 sigaddq+0x108 7003c7a8 1 70515200 pm_ioctl+0x187c ------------------------------------------------------ Total 4 buffers, 376 bytes
Using the bufctl pointers, you can obtain the complete stack backtrace of the allocation by applying the bufctl_audit macro:
> 70d3b1a0$<bufctl_audit 0x70d3b1a0: next addr slab 70a049c0 70d03b28 70bb7480 0x70d3b1ac: cache timestamp thread 7003a028 13f7cf63b3 70b38380 0x70d3b1bc: lastlog contents stackdepth 700d6e60 0 5 0x70d3b1c8: kmem_alloc+0x30 sigaddq+0x108 sigsendproc+0x210 sigqkill+0x90 kill+0x28
The programmer can usually use the bufctl_audit information and the allocation stack trace to quickly track down the code path that leaks the given buffer.