This patch hails from Git for Windows (where the Cygwin runtime is used
in the form of a slightly modified MSYS2 runtime), where it is a
well-established technique to let the `$HOME` variable define where the
current user's home directory is, falling back to `$HOMEDRIVE$HOMEPATH`
and `$USERPROFILE`.
The idea is that we want to share user-specific settings between
programs, whether they be Cygwin, MSYS2 or not. Unfortunately, we
cannot blindly activate the "db_home: windows" setting because in some
setups, the user's home directory is set to a hidden directory via an
UNC path (\\share\some\hidden\folder$) -- something many programs
cannot handle correctly, e.g. `cmd.exe` and other native Windows
applications that users want to employ as Git helpers.
The established technique is to allow setting the user's home directory
via the environment variables mentioned above: `$HOMEDRIVE$HOMEPATH` or
`$USERPROFILE`. This has the additional advantage that it is much
faster than querying the Windows user database.
Of course this scheme needs to be opt-in. For that reason, it needs
to be activated explicitly via `db_home: env` in `/etc/nsswitch.conf`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
So far, the addresses printed for the shared regions of a process
were faked. The assumption was that the shared regions are always
in the same place in all processes, so we just printed the addresses
of the current process. This is no safe bet. The only safe bet is
the address of the cygheap. So keep track of the addresses in the
cygheap and read the addresses from the cygheap of the observed
processes. Add output for the shared console.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Originally the code was written to allow three ways of prefixing
accounts and to freely define a domain/account separator. This code
has been disabled even before being officially released, and it was
never re-enabled. Given there has been no complaints for eight years
now, drop this code eventually. Just add a macro to define the
domain/account separator statically.
Fixes: cc332c9e27 ("(cygheap_pwdgrp::nss_init_line): Disable db_prefix
and db_separator settings. Add comment")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Every time the cygheap is initialized, that is, on each fork
or exec, cygheap_init() *again* computes the bucket size values
and stores them in the cgyheap, albeit they are always the
same values anyway.
Make bucket_val a local const array, statically initialized
instead.
Fixes: 61522196c7 ("* Merge in cygwin-64bit-branch.)"
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
One reason that ASLR is tricky is the fact that the cygheap
is placed at the end of the DLL and especially that it's expected
to be growable. To support ASLR, this construct must go.
Define dedicated cygheap memory region and reserve entire region.
Commit 3 Megs, as was the default size of the cygheap before.
Fix linker script accordingly, drop a now useless version check
in get_cygwin_startup_info().
Johannes Schindelin
Corinna Vinschen