Re: [LTP] [PATCH v1 1/2] fcntl{34, 36}: Only use fcntl64 with 32bit abi

[Richard Palethorpe <rpalethorpe@suse.de>]

Hello,

Edward Liaw via ltp <ltp@lists.linux.it> writes:

> Fixes: 7643115aaacb ("fcntl{34,36}: Always use 64-bit flock struct to avoid EINVAL")
>
> On Android arm64, tst_kernel_bits is disregarding the abi, so compiling
> with the 32bit abi is calling the fcntl syscall instead of fcntl64.
> The

IIRC that's the idea because fcntl64 doesn't exist on a 64bit
kernel.

So if you compile the test with -m32/32bit ABI on x86_64 64bit kernel
then you will get ENOSYS? If not then I suppose it is fine.

> fcntl syscall is not compatible with the flock64 struct being passed
> (this doesn't seem to be the case with x86_64, only with arm64).
>
> This changes it to only use the fcntl64 compat syscall with the 32bit
> abi.
>
> Signed-off-by: Edward Liaw <edliaw@google.com>
> ---
>  testcases/kernel/syscalls/fcntl/fcntl_common.h | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/fcntl/fcntl_common.h b/testcases/kernel/syscalls/fcntl/fcntl_common.h
> index 5c130a784..485a31367 100644
> --- a/testcases/kernel/syscalls/fcntl/fcntl_common.h
> +++ b/testcases/kernel/syscalls/fcntl/fcntl_common.h
> @@ -10,6 +10,11 @@
>  #include "lapi/abisize.h"
>  #include "lapi/fcntl.h"
>  
> +#if defined(TST_ABI64)
> +#define FCNTL_COMPAT(fd, cmd, flock) \
> +	SAFE_FCNTL(fd, cmd, flock)
> +
> +#else
>  struct my_flock64 {
>  	int16_t l_type;
>  	int16_t l_whence;
> @@ -43,8 +48,8 @@ static inline int fcntl_compat(const char *file, const int line, const char *cmd
>  		.l_len = lck->l_len,
>  		.l_pid = lck->l_pid,
>  	};
> -	const int sysno = tst_kernel_bits() > 32 ? __NR_fcntl : __NR_fcntl64;
> -	const int ret = tst_syscall(sysno, fd, cmd, &l64);
> +
> +	const int ret = tst_syscall(__NR_fcntl64, fd, cmd, &l64);
>  
>  	lck->l_type = l64.l_type;
>  	lck->l_whence = l64.l_whence;
> @@ -57,7 +62,7 @@ static inline int fcntl_compat(const char *file, const int line, const char *cmd
>  
>  	tst_brk_(file, line, TBROK | TERRNO,
>  		 "%s(%d, %s, { %d, %d, %"PRId64", %"PRId64", %d })",
> -		 tst_kernel_bits() > 32 ? "fcntl" : "fcntl64",
> +		 "fcntl64",
>  		 fd,
>  		 cmd_name,
>  		 l64.l_type, l64.l_whence, l64.l_start, l64.l_len, l64.l_pid);
> @@ -67,5 +72,6 @@ static inline int fcntl_compat(const char *file, const int line, const char *cmd
>  
>  #define FCNTL_COMPAT(fd, cmd, flock) \
>  	fcntl_compat(__FILE__, __LINE__, #cmd, fd, cmd, flock)
> +#endif
>  
>  #endif /* FCNTL_COMMON_H__ */
> -- 
> 2.40.1.495.gc816e09b53d-goog


-- 
Thank you,
Richard.

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