On Feb 17 14:56, Ken Brown wrote:
> On 2/17/2019 4:13 AM, Corinna Vinschen wrote:
> > On Feb 17 10:08, Corinna Vinschen wrote:
> >> On Feb 17 00:11, Ken Brown wrote:
> >>> I'm getting a lot of errors like this when building emacs from its git
> >>> repo:
> >>>
> >> Weird. I built at least gawk and openssh with 3.0 already and I
> >> didn't notice this problem.
> >>
> >>> A bisection points to the following as the first bad commit:
> >>>[...]
> >>> I'll try to do some debugging and/or provide further information
> >>> tomorrow, but I thought I'd start with this preliminary report.
> >>
> >> That would be nice. It's not clear to me which permission is missing.
> >> The first part of the patch has been reverted in 3.0.0, so
> >> child_info_spawn::get_parent_handle opens the parent with
> >> PROCESS_VM_READ again. The second patch has been reworked as well,m
> >> the current perms are
> >>
> >> PROCESS_QUERY_LIMITED_INFORMATION | PROCESS_VM_READ | SYNCHRONIZE
> >>
> >> If I may place a bet, please try to replace
> >> PROCESS_QUERY_LIMITED_INFORMATION with PROCESS_QUERY_INFORMATION
>
> That didn't change anything. Just to make sure I understood correctly,
> here's
> what I tried:
>
> --- a/winsup/cygwin/sigproc.cc
> +++ b/winsup/cygwin/sigproc.cc
> @@ -814,7 +814,7 @@ child_info::child_info (unsigned in_cb, child_info_types
> chtype,
> allow the child to copy cygheap etc. from the parent to itself. If
> we're forking, we also need handle duplicate access. */
> parent = NULL;
> - DWORD perms = PROCESS_QUERY_LIMITED_INFORMATION | PROCESS_VM_READ
> + DWORD perms = PROCESS_QUERY_INFORMATION | PROCESS_VM_READ
> | SYNCHRONIZE;
> if (type == _CH_FORK)
> {
>
> > On second thought, an even better candidate may be PROCESS_VM_OPERATION.
>
> That's even worse. With that change, simply invoking 'make' leads to
> the same error.
PROCESS_VM_OPERATION has to be specified additionally, not replacing
PROCESS_QUERY_{LIMITED_}INFORMATION. Sorry if that wasn't clear.
Another idea is to specify all process-specific permissions from
https://docs.microsoft.com/en-us/windows/desktop/ProcThread/process-security-and-access-rights
and then eliminate backwards.
Corinna
--
Corinna Vinschen
Cygwin Maintainer
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