DavidSpickett marked 2 inline comments as done. DavidSpickett added inline comments.
================ Comment at: lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp:1357 + + if (error.Fail()) + return error; ---------------- DavidSpickett wrote: > DavidSpickett wrote: > > omjavaid wrote: > > > ptrace request is a success if number of tags requested is not equal to > > > no of tags read? If not then this and following condition may be > > > redundant. > > Well ptracewrapper doesn't check the iovec, but I'll check the kernel > > source to see if it's actually possible for it to fail that way. > In `linux/arch/arm64/kernel/mte.c` `__access_remote_tags` there is a comment: > ``` > +/* > + * Access MTE tags in another process' address space as given in mm. Update > + * the number of tags copied. Return 0 if any tags copied, error otherwise. > + * Inspired by __access_remote_vm(). > + */ > ``` > > *any tags* being the key words. > > So the scenario is: > * ask to read from addr X in page 0, with length of pagesize+some so the > range spills into page 1 > * kernel can access page 0, reads tags until the end of the page > * tries to access page 1 to read the rest, fails, returns 0 (success) since > *some* tags were read > * we see the ptrace call succeeded but with less tags than we expected > > I don't see it's worth dealing with this corner case here since lldb will > look before it leaps. It would have errored much earlier here because either > page 1 isn't in the tracee's memory regions or it wasn't MTE enabled. > > Added a comment in the code too. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D95601/new/ https://reviews.llvm.org/D95601 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
