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 <cyg...@jdrake.com>
---
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
