Re: [PATCH v2] linux-user: Fix strace output for s390x mmap()

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 20/11/24 22:26, Ilya Leoshkevich wrote:
> print_mmap() assumes that mmap() receives arguments via memory if
> mmap2() is present. s390x (as opposed to s390) does not fit this
> pattern: it does not have mmap2(), but mmap() still receives arguments
> via memory.
> 
> Fix by sharing the detection logic between syscall.c and strace.c.
> 
> Cc: qemu-stable@nongnu.org
> Fixes: d971040c2d16 ("linux-user: Fix strace output for old_mmap")
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
> 
> v1: https://lore.kernel.org/qemu-devel/20241119211138.148806-1-iii@linux.ibm.com/
> v1 -> v2: Share the detection logic between syscall.c and strace.c
>            (Richard).
> 
>   linux-user/strace.c       | 2 +-
>   linux-user/syscall.c      | 5 +----
>   linux-user/syscall_defs.h | 7 +++++++
>   3 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index b70eadc19ef..9c55f39b095 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -3971,7 +3971,7 @@ print_mmap(CPUArchState *cpu_env, const struct syscallname *name,
>   {
>       return print_mmap_both(cpu_env, name, arg0, arg1, arg2, arg3,
>                              arg4, arg5,
> -#if defined(TARGET_NR_mmap2)
> +#ifdef TARGET_ARCH_WANT_SYS_OLD_MMAP

We still want to print for mmap2, so:

   #if defined(TARGET_NR_mmap2) || defined(TARGET_ARCH_WANT_SYS_OLD_MMAP)

>                               true
>   #else
>                               false
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 0279f235768..1ce4c79784f 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -10588,10 +10588,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
>           return ret;
>   #ifdef TARGET_NR_mmap
>       case TARGET_NR_mmap:
> -#if (defined(TARGET_I386) && defined(TARGET_ABI32)) || \
> -    (defined(TARGET_ARM) && defined(TARGET_ABI32)) || \
> -    defined(TARGET_M68K) || defined(TARGET_MICROBLAZE) \
> -    || defined(TARGET_S390X)
> +#ifdef TARGET_ARCH_WANT_SYS_OLD_MMAP
>           {
>               abi_ulong *v;
>               abi_ulong v1, v2, v3, v4, v5, v6;
> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
> index 0e08dfae3e4..faad9147c91 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -2766,4 +2766,11 @@ struct target_open_how_ver0 {
>   #define RESOLVE_NO_SYMLINKS     0x04
>   #endif
>   
> +#if (defined(TARGET_I386) && defined(TARGET_ABI32)) || \
> +    (defined(TARGET_ARM) && defined(TARGET_ABI32)) || \
> +    defined(TARGET_M68K) || defined(TARGET_MICROBLAZE) || \
> +    defined(TARGET_S390X)
> +#define TARGET_ARCH_WANT_SYS_OLD_MMAP
> +#endif
> +
>   #endif