* Namhyung Kim <namhy...@kernel.org> wrote: > Unwinding optimized binaries using frame pointer gives garbage. Check > callchain address and stop if it's under vm.mmap_min_addr sysctl value. > > Before: > $ perf report --stdio --no-children -g callee > ... > > 1.37% perf [kernel.vmlinux] [k] smp_call_function_single > | > ---smp_call_function_single > _perf_event_enable > perf_event_for_each_child > perf_ioctl > do_vfs_ioctl > sys_ioctl > entry_SYSCALL_64_fastpath > __GI___ioctl > 0 > 0 > 0x1c5aa70 > 0x1c5b910 > 0x1c5aa70 > 0x1c5b910 > 0x1c5aa70 > 0x1c5b910 > 0x1c5aa70 > 0x1c5b910 > 0x1c5aa70 > 0x1c5b910 > ... > > After: > $ perf report --stdio --no-children -g callee > ... > > 1.37% perf [kernel.vmlinux] [k] smp_call_function_single > | > ---smp_call_function_single > _perf_event_enable > perf_event_for_each_child > perf_ioctl > do_vfs_ioctl > sys_ioctl > entry_SYSCALL_64_fastpath > __GI___ioctl
In addition to that, would it make sense to terminate the callchain with an indicator that we found something anomalous? Such an extra line: ... would not be intrusive, but would tell the informed reader that it's not a normal ending of the call chain. This assumes that we can tell apart 'normal end of call chain' from 'seems to end with garbage poiner' cases - can do we that? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/