* Oleg Nesterov <o...@redhat.com> [2014-05-19 20:40:54]: > Sorry for double-posting, but it seems that this patch didn't reach > lkml. Let me resend it just on case. Plus another patch in reply, on > top of this change. > > ------------------------------------------------------------------------------- > Subject: [PATCH] uprobes: Shift ->readpage check from __copy_insn() to > uprobe_register() > > copy_insn() fails with -EIO if ->readpage == NULL, but this error > is not propagated unless uprobe_register() path finds ->mm which > already mmaps this file. In this case (say) "perf record" does not > actually install the probe, but the user can't know about this. > > Move this check into uprobe_register() so that this problem can be > detected earlier and reported to user. > > Note: this is still not perfect, > > - copy_insn() and arch_uprobe_analyze_insn() should be called > by uprobe_register() but this is not simple, we need vm_file > for read_mapping_page() (although perhaps we can pass NULL), > and we need ->mm for is_64bit_mm() (although this logic is > broken anyway). > > - uprobe_register() should be called by create_trace_uprobe(), > not by probe_event_enable(), so that an error can be detected > at "perf probe -x" time. This also needs more changes in the > core uprobe code, uprobe register/unregister interface was > poorly designed from the very beginning. > > Reported-by: Denys Vlasenko <dvlas...@redhat.com> > Signed-off-by: Oleg Nesterov <o...@redhat.com>
Acked-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com> -- Thanks and Regards Srikar Dronamraju -- 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/
