On 03/13, Sergio Durigan Junior wrote: > > On Thursday, March 12 2015, Oleg Nesterov wrote: > > > And it seems that we all agree that the kernel should not dump this vma > > too. Could you confirm that this is fine from gdb pov just in case? > > Yes, this is what we expect from the GDB side. This mapping is marked > as "dd", so it does not make sense to dump it.
OK. > While I have you guys, would it be possible for the Linux kernel to > include a new flag on VmFlags to uniquely identify an anonymous mapping? Note that "anonymous" is not the right term here... I mean it is a bit confusing. Lets discuss this again on debug-list, then we will see if gdb needs more info from kernel. > Currently, there is no easy way to do that from userspace. My patch > implements the following heuristic on GDB: > > if (pathname == "/dev/zero (deleted)" > || pathname == "/SYSV%08x (deleted)" > || pathname == "<file> (deleted)" And for example, this is not anonymous mapping. But, > mapping is anonymous; I agree, gdb should treat it as anonymous. > However, this can be fragile. The Linux kernel checks for i_nlink == 0, Yes, as we already disccussed, I think the kernel should be changed. It should do something like shmem_mapping() || d_unlinked(), I think. But this needs another discussion on lkml, and in another thread. Oleg. -- 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/
