================
@@ -247,26 +247,34 @@ bool
ProcessFreeBSDKernelCore::DoUpdateThreadList(ThreadList &old_thread_list,
// https://cgit.freebsd.org/src/tree/sys/sys/param.h
constexpr size_t fbsd_maxcomlen = 19;
- // Iterate through a linked list of all processes. New processes are added
- // to the head of this list. Which means that earlier PIDs are actually at
- // the end of the list, so we have to walk it backwards. First collect all
- // the processes in the list order.
- std::vector<lldb::addr_t> process_addrs;
+ // Iterate through a linked list of all processes then order incrementally
+ // by pid. Though new processes are added to the head of this list, process
+ // ids may be reused as well. So we cannot rely on it being in a particular
+ // order.
+ std::vector<std::pair<lldb::addr_t, int32_t>> process_addrs;
if (lldb::addr_t allproc_addr = FindSymbol("allproc");
allproc_addr != LLDB_INVALID_ADDRESS) {
for (lldb::addr_t proc = ReadPointerFromMemory(allproc_addr, error);
proc != 0 && proc != LLDB_INVALID_ADDRESS && error.Success();
- proc = ReadPointerFromMemory(proc + offset_p_list, error))
- process_addrs.push_back(proc);
+ proc = ReadPointerFromMemory(proc + offset_p_list, error)) {
+ int32_t pid =
+ ReadSignedIntegerFromMemory(proc + offset_p_pid, 4, -1, error);
+ if (error.Fail())
+ return false;
+ process_addrs.emplace_back(proc, pid);
+ }
}
- // Processes are in the linked list in descending PID order, so we must
walk
- // them in reverse to get ascending PID order.
- for (auto proc_it = process_addrs.rbegin(); proc_it !=
process_addrs.rend();
- ++proc_it) {
- lldb::addr_t proc = *proc_it;
- int32_t pid =
- ReadSignedIntegerFromMemory(proc + offset_p_pid, 4, -1, error);
+ if (error.Fail())
+ return false;
----------------
DavidSpickett wrote:
This looks redundant but on closer inspection, I think it's trying to catch
`proc = ReadPointerFromMemory(proc + offset_p_list, error)` failing.
We could move that call into the body of the loop. Which is more awkward from a
for loop point of view but clearer that we immediately return if it fails. It's
all a bit tangled because you also have to check that `lldb::addr_t proc =
ReadPointerFromMemory(allproc_addr, error);` did not fail, and having `&&
error.Success()` handles everything nicely, though it is a bit cryptic.
So I don't think we change the loop, but please do add a comment here to say it
catches any failure to read the address of the next process struct (whatever
the correct answer is there).
https://github.com/llvm/llvm-project/pull/187976
_______________________________________________
lldb-commits mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
