On Wed, 30 Apr 2025 12:45:56 -0700 (PDT)
Jeremy Drake wrote:
> The DL_info::dli_fname member is actually PATH_MAX bytes, so specify
> that (larger) size to cygwin_conv_path rather than MAX_PATH.
>
> Also, use a tmp_pathbuf for the GetModuleFileNameW buffer, so that any
> buffer size limitation will definitely be due to the size of dli_fname,
> and add a static_assert of the size of dli_fname so we can be sure we're
> using the right size constant here.
>
> Fixes: c8432a01c840 ("Implement dladdr() (partially)")
> Addresses:
> https://github.com/rust-lang/backtrace-rs/pull/704#issuecomment-2833782574
> Signed-off-by: Jeremy Drake <[email protected]>
> ---
> winsup/cygwin/dlfcn.cc | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/winsup/cygwin/dlfcn.cc b/winsup/cygwin/dlfcn.cc
> index 10bd0ac1f4..9b6bb55b34 100644
> --- a/winsup/cygwin/dlfcn.cc
> +++ b/winsup/cygwin/dlfcn.cc
> @@ -421,14 +421,16 @@ dladdr (const void *addr, Dl_info *info)
> /* Get the module filename. This pathname may be in short-, long- or //?/
> format, depending on how it was specified when loaded, but we assume
> this
> is always an absolute pathname. */
> - WCHAR fname[MAX_PATH];
> - DWORD length = GetModuleFileNameW (hModule, fname, MAX_PATH);
> - if ((length == 0) || (length == MAX_PATH))
> + tmp_pathbuf tp;
> + PWCHAR fname = tp.w_get ();
> + DWORD length = GetModuleFileNameW (hModule, fname, NT_MAX_PATH);
> + if ((length == 0) || (length == NT_MAX_PATH))
> return 0;
>
> /* Convert to a cygwin pathname */
> + static_assert (sizeof (info->dli_fname) == PATH_MAX);
> ssize_t conv = cygwin_conv_path (CCP_WIN_W_TO_POSIX | CCP_ABSOLUTE, fname,
> - info->dli_fname, MAX_PATH);
> + info->dli_fname, PATH_MAX);
> if (conv)
> return 0;
>
> --
> 2.49.0.windows.1
>
Thanks for the patch. LGTM. Pushed.
--
Takashi Yano <[email protected]>
