v4l2: v4l2_compat: Intercept open64, openat64, and mmap64

Some applications (eg. Firefox, Google Chrome, Skype) use open64,
openat64, and mmap64 instead of their non-64 versions that we currently
intercept. Intercept these calls as well. _LARGEFILE64_SOURCE needs to
be set so that the 64-bit symbols are available and not synonymous to
the non-64-bit versions on 64-bit systems.

Also, since we set _FILE_OFFSET_BITS to 32 to force the various open and
mmap symbols that we export to not be the 64-bit versions, our dlsym to
get the original open and mmap calls will not automatically be converted
to their 64-bit versions. Since we intercept both 32-bit and 64-bit
versions of open and mmap, we should be using the 64-bit version to
service both. Fetch the 64-bit versions of openat and mmap directly.

musl defines the 64-bit symbols as macros that are equivalent to the
non-64-bit symbols, so we put compile guards that check if the 64-bit
symbols are defined.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> # Compile with musl
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/v4l2/meson.build b/src/v4l2/meson.build
index 0fb941ea..f2e4aaf2 100644
--- a/src/v4l2/meson.build
+++ b/src/v4l2/meson.build
@@ -15,6 +15,7 @@ v4l2_compat_cpp_args = [
     # file operations, disable transparent large file support.
     '-U_FILE_OFFSET_BITS',
     '-D_FILE_OFFSET_BITS=32',
+    '-D_LARGEFILE64_SOURCE',
     '-fvisibility=hidden',
 ]