futex_op.c

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// SPDX-License-Identifier: GPL-2.0
#include <linux/futex.h>

#ifndef FUTEX_WAIT_BITSET
#define FUTEX_WAIT_BITSET     9
#endif
#ifndef FUTEX_WAKE_BITSET
#define FUTEX_WAKE_BITSET    10
#endif
#ifndef FUTEX_WAIT_REQUEUE_PI
#define FUTEX_WAIT_REQUEUE_PI    11
#endif
#ifndef FUTEX_CMP_REQUEUE_PI
#define FUTEX_CMP_REQUEUE_PI     12
#endif
#ifndef FUTEX_CLOCK_REALTIME
#define FUTEX_CLOCK_REALTIME    256
#endif

static size_t syscall_arg__scnprintf_futex_op(char *bf, size_t size, struct syscall_arg *arg)
{
    enum syscall_futex_args {
        SCF_UADDR   = (1 << 0),
        SCF_OP      = (1 << 1),
        SCF_VAL     = (1 << 2),
        SCF_TIMEOUT = (1 << 3),
        SCF_UADDR2  = (1 << 4),
        SCF_VAL3    = (1 << 5),
    };
    int op = arg->val;
    int cmd = op & FUTEX_CMD_MASK;
    size_t printed = 0;

    switch (cmd) {
#define P_FUTEX_OP(n) case FUTEX_##n: printed = scnprintf(bf, size, #n);
    P_FUTEX_OP(WAIT);       arg->mask |= SCF_VAL3|SCF_UADDR2;         break;
    P_FUTEX_OP(WAKE);       arg->mask |= SCF_VAL3|SCF_UADDR2|SCF_TIMEOUT; break;
    P_FUTEX_OP(FD);         arg->mask |= SCF_VAL3|SCF_UADDR2|SCF_TIMEOUT; break;
    P_FUTEX_OP(REQUEUE);        arg->mask |= SCF_VAL3|SCF_TIMEOUT;            break;
    P_FUTEX_OP(CMP_REQUEUE);    arg->mask |= SCF_TIMEOUT;             break;
    P_FUTEX_OP(CMP_REQUEUE_PI); arg->mask |= SCF_TIMEOUT;             break;
    P_FUTEX_OP(WAKE_OP);                              break;
    P_FUTEX_OP(LOCK_PI);        arg->mask |= SCF_VAL3|SCF_UADDR2|SCF_TIMEOUT; break;
    P_FUTEX_OP(UNLOCK_PI);      arg->mask |= SCF_VAL3|SCF_UADDR2|SCF_TIMEOUT; break;
    P_FUTEX_OP(TRYLOCK_PI);     arg->mask |= SCF_VAL3|SCF_UADDR2;         break;
    P_FUTEX_OP(WAIT_BITSET);    arg->mask |= SCF_UADDR2;              break;
    P_FUTEX_OP(WAKE_BITSET);    arg->mask |= SCF_UADDR2;              break;
    P_FUTEX_OP(WAIT_REQUEUE_PI);                          break;
    default: printed = scnprintf(bf, size, "%#x", cmd);           break;
    }

    if (op & FUTEX_PRIVATE_FLAG)
        printed += scnprintf(bf + printed, size - printed, "|PRIV");

    if (op & FUTEX_CLOCK_REALTIME)
        printed += scnprintf(bf + printed, size - printed, "|CLKRT");

    return printed;
}

#define SCA_FUTEX_OP  syscall_arg__scnprintf_futex_op