qemu/linux-user/s390x/target_syscall.h
Filip Bozuta 02e5d7d78e linux-user: Add strace support for printing arguments of syscalls used to lock and unlock memory
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>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200811164553.27713-4-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-08-27 12:29:50 +02:00

36 lines
824 B
C

#ifndef S390X_TARGET_SYSCALL_H
#define S390X_TARGET_SYSCALL_H
/* this typedef defines how a Program Status Word looks like */
typedef struct {
abi_ulong mask;
abi_ulong addr;
} __attribute__ ((aligned(8))) target_psw_t;
/*
* The pt_regs struct defines the way the registers are stored on
* the stack during a system call.
*/
#define TARGET_NUM_GPRS 16
struct target_pt_regs {
abi_ulong args[1];
target_psw_t psw;
abi_ulong gprs[TARGET_NUM_GPRS];
abi_ulong orig_gpr2;
unsigned short ilen;
unsigned short trap;
};
#define UNAME_MACHINE "s390x"
#define UNAME_MINIMUM_RELEASE "2.6.32"
#define TARGET_CLONE_BACKWARDS2
#define TARGET_MINSIGSTKSZ 2048
#define TARGET_MCL_CURRENT 1
#define TARGET_MCL_FUTURE 2
#define TARGET_MCL_ONFAULT 4
#endif /* S390X_TARGET_SYSCALL_H */