Re: [PATCH v2 3/4] linux-user: Add strace support for printing arguments of syscalls used to lock and unlock memory

[Laurent Vivier]

Le 13/07/2020 à 11:50, Filip Bozuta a écrit :
> This patch implements strace argument printing functionality for following 
> syscalls:
> 
>     * mlock, munlock, mlockall, munlockall - lock and unlock memory
> 
>        int mlock(const void *addr, size_t len)
>        int munlock(const void *addr, size_t len)
>        int mlockall(int flags)
>        int munlockall(void)
>        man page: https://man7.org/linux/man-pages/man2/mlock.2.html
> 
> Implementation notes:
> 
>     Syscall mlockall() takes an argument that is composed of predefined values
>     which represent flags that determine the type of locking operation that is
>     to be performed. For that reason, a printing function "print_mlockall" was
>     stated in file "strace.list". This printing function uses an already 
> existing
>     function "print_flags()" to print the "flags" argument.  These flags are 
> stated
>     inside an array "mlockall_flags" that contains values of type "struct 
> flags".
>     These values are instantiated using an existing macro "FLAG_TARGET()" that
>     crates aproppriate target flag values based on those defined in files
>     '/target_syscall.h'. These target flag values were changed from
>     "TARGET_MLOCKALL_MCL*" to "TARGET_MCL_*" so that they can be 
> aproppriately set
>     and recognised in "strace.c" with "FLAG_TARGET()". Value for "MCL_ONFAULT"
>     was added in this patch. This value was also added in "syscall.c" in 
> function
>     "target_to_host_mlockall_arg()". Because this flag value was added in 
> kernel
>     version 4.4, it is enwrapped in an #ifdef directive (both in "syscall.c" 
> and
>     in "strace.c") as to support older kernel versions.
>     The other syscalls have only primitive argument types, so the
>     rest of the implementation was handled by stating an appropriate
>     printing format in file "strace.list". Syscall mlock2() is not 
> implemented in
>     "syscall.c" and thus it's argument printing is not implemented in this 
> patch.
> 
> Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
> ---
>  linux-user/aarch64/target_syscall.h    |  5 +++--
>  linux-user/alpha/target_syscall.h      |  5 +++--
>  linux-user/arm/target_syscall.h        |  6 ++++--
>  linux-user/cris/target_syscall.h       |  5 +++--
>  linux-user/hppa/target_syscall.h       |  5 +++--
>  linux-user/i386/target_syscall.h       |  5 +++--
>  linux-user/m68k/target_syscall.h       |  6 +++---
>  linux-user/microblaze/target_syscall.h |  5 +++--
>  linux-user/mips/target_syscall.h       |  5 +++--
>  linux-user/mips64/target_syscall.h     |  5 +++--
>  linux-user/nios2/target_syscall.h      |  5 +++--
>  linux-user/openrisc/target_syscall.h   |  5 +++--
>  linux-user/ppc/target_syscall.h        |  5 +++--
>  linux-user/riscv/target_syscall.h      |  5 +++--
>  linux-user/s390x/target_syscall.h      |  5 +++--
>  linux-user/sh4/target_syscall.h        |  5 +++--
>  linux-user/sparc/target_syscall.h      |  5 +++--
>  linux-user/sparc64/target_syscall.h    |  5 +++--
>  linux-user/strace.c                    | 21 +++++++++++++++++++++
>  linux-user/strace.list                 |  8 ++++----
>  linux-user/syscall.c                   | 10 ++++++++--
>  linux-user/tilegx/target_syscall.h     |  5 +++--
>  linux-user/x86_64/target_syscall.h     |  5 +++--
>  linux-user/xtensa/target_syscall.h     |  5 +++--
>  24 files changed, 97 insertions(+), 49 deletions(-)
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>