On Tue 23-01-18 21:28:28, Anshuman Khandual wrote: > On 01/23/2018 06:15 PM, Michal Hocko wrote: > > On Tue 23-01-18 16:55:18, Anshuman Khandual wrote: > >> On 01/17/2018 01:37 PM, Michal Hocko wrote: > >>> On Thu 11-01-18 15:38:37, Anshuman Khandual wrote: > >>>> On 01/09/2018 09:43 PM, Michal Hocko wrote: > >>> [...] > >>>>> Did you manage to catch _who_ is requesting that anonymous mapping? Do > >>>>> you need a help with the debugging patch? > >>>> > >>>> Not yet, will get back on this. > >>> > >>> ping? > >> > >> Hey Michal, > >> > >> Missed this thread, my apologies. This problem is happening only with > >> certain binaries like 'sed', 'tmux', 'hostname', 'pkg-config' etc. As > >> you had mentioned before the map request collision is happening on > >> [10030000, 10040000] and [10030000, 10040000] ranges only which is > >> just a single PAGE_SIZE. You asked previously that who might have > >> requested the anon mapping which is already present in there ? Would > >> not that be the same process itself ? I am bit confused. > > > > We are early in the ELF loading. If we are mapping over an existing > > mapping then we are effectivelly corrupting it. In other words exactly > > what this patch tries to prevent. I fail to see what would be a relevant > > anon mapping this early and why it would be colliding with elf > > segements. > > > >> Would it be > >> helpful to trap all the mmap() requests from any of the binaries > >> and see where we might have created that anon mapping ? > > > > Yeah, that is exactly what I was suggesting. Sorry for not being clear > > about that. > > > > Tried to instrument just for the 'sed' binary and dont see any where > it actually requests the anon VMA which got hit when loading the ELF > section which is strange. All these requested flags here already has > MAP_FIXED_NOREPLACE (0x100000). Wondering from where the anon VMA > actually came from. Could you try to dump backtrace? -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
