Hi Peter,
On 30/03/2023 17:06, Peter Seiderer wrote:
> Compiling for RPi4 (64-bit) using buildroot failes with the following
> error:
>
> .../host/bin/aarch64-buildroot-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I../.. -I../../utils/common -I.../aarch64-buildroot-linux-gnu/sysroot/usr/include/json-c -I../../lib/include -Wall -Wpointer-arith -D_GNU_SOURCE -I../../include -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -std=gnu++11 -c libv4l2tracer.cpp -fPIC -DPIC -o .libs/libv4l2tracer_la-libv4l2tracer.o
> /tmp/ccfbectY.s: Assembler messages:
> /tmp/ccfbectY.s:208: Error: symbol `open64' is already defined
> /tmp/ccfbectY.s:762: Error: symbol `mmap64' is already defined
>
> The preprocessor output shows:
>
> [...]
> extern "C" {
> # 61 ".../host/aarch64-buildroot-linux-gnu/sysroot/usr/include/sys/mman.h" 3 4
> extern void * mmap (void *__addr, size_t __len, int __prot, int __flags, int __fd, __off64_t __offset) noexcept (true) __asm__ ("" "mmap64");
> [...]
> extern void *mmap64 (void *__addr, size_t __len, int __prot,
> int __flags, int __fd, __off64_t __offset) noexcept (true);
>
> And host/aarch64-buildroot-linux-gnu/sysroot/usr/include/sys/mman.h:
>
> 56 #ifndef __USE_FILE_OFFSET64
> 57 extern void *mmap (void *__addr, size_t __len, int __prot,
> 58 int __flags, int __fd, __off_t __offset) __THROW;
> 59 #else
> 60 # ifdef __REDIRECT_NTH
> 61 extern void * __REDIRECT_NTH (mmap,
> 62 (void *__addr, size_t __len, int __prot,
> 63 int __flags, int __fd, __off64_t __offset),
> 64 mmap64);
> 65 # else
> 66 # define mmap mmap64
> 67 # endif
> 68 #endif
> 69 #ifdef __USE_LARGEFILE64
> 70 extern void *mmap64 (void *__addr, size_t __len, int __prot,
> 71 int __flags, int __fd, __off64_t __offset) __THROW;
> 72 #endif
>
> Fix it by applying the same undef _LARGEFILE_SOURCE/_FILE_OFFSET_BITS,
> define _LARGEFILE64_SOURCE as in as in lib/libv4l1/v4l1compat.c
If I look at 'man feature_test_macros', then that man page suggests that
_LARGEFILE64_SOURCE is out of date and instead you should use
'#define _FILE_OFFSET_BITS 64'.
Can you test that? If this works, then it should be applied to v4l1compat.c
as well.
>
> Signed-off-by: Peter Seiderer <ps.report@xxxxxxx>
> ---
> Notes:
>
> - maybe the 'defined(linux) && defined(__GLIBC__)' protection
> present in lib/libv4l1/v4l1compat.c for open64/mmap64 is needed
> for non glibc compiles of utils/v4l2-tracer/libv4l2tracer.cpp too?
I think we need this too. If nothing else, it is consistent.
Regards,
Hans
> ---
> utils/v4l2-tracer/libv4l2tracer.cpp | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/utils/v4l2-tracer/libv4l2tracer.cpp b/utils/v4l2-tracer/libv4l2tracer.cpp
> index a9f039c7..1e3900db 100644
> --- a/utils/v4l2-tracer/libv4l2tracer.cpp
> +++ b/utils/v4l2-tracer/libv4l2tracer.cpp
> @@ -3,6 +3,11 @@
> * Copyright 2022 Collabora Ltd.
> */
>
> +/* ensure we see *64 variants and they aren't transparently used */
> +#undef _LARGEFILE_SOURCE
> +#undef _FILE_OFFSET_BITS
> +#define _LARGEFILE64_SOURCE 1
> +
> #include "trace.h"
> #include <dlfcn.h>
> #include <stdarg.h>
