prctl.c

Go to the documentation of this file.

/*
 * trace/beauty/prctl.c
 *
 *  Copyright (C) 2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Released under the GPL v2. (and only v2, not any later version)
 */

#include "trace/beauty/beauty.h"
#include <linux/kernel.h>
#include <uapi/linux/prctl.h>

#include "trace/beauty/generated/prctl_option_array.c"

static size_t prctl__scnprintf_option(int option, char *bf, size_t size)
{
    static DEFINE_STRARRAY(prctl_options);
    return strarray__scnprintf(&strarray__prctl_options, bf, size, "%d", option);
}

static size_t prctl__scnprintf_set_mm(int option, char *bf, size_t size)
{
    static DEFINE_STRARRAY(prctl_set_mm_options);
    return strarray__scnprintf(&strarray__prctl_set_mm_options, bf, size, "%d", option);
}

size_t syscall_arg__scnprintf_prctl_arg2(char *bf, size_t size, struct syscall_arg *arg)
{
    int option = syscall_arg__val(arg, 0);

    if (option == PR_SET_MM)
        return prctl__scnprintf_set_mm(arg->val, bf, size);
    /*
     * We still don't grab the contents of pointers on entry or exit,
     * so just print them as hex numbers
     */
    if (option == PR_SET_NAME)
        return syscall_arg__scnprintf_hex(bf, size, arg);

    return syscall_arg__scnprintf_long(bf, size, arg);
}

size_t syscall_arg__scnprintf_prctl_arg3(char *bf, size_t size, struct syscall_arg *arg)
{
    int option = syscall_arg__val(arg, 0);

    if (option == PR_SET_MM)
        return syscall_arg__scnprintf_hex(bf, size, arg);

    return syscall_arg__scnprintf_long(bf, size, arg);
}

size_t syscall_arg__scnprintf_prctl_option(char *bf, size_t size, struct syscall_arg *arg)
{
    unsigned long option = arg->val;
    enum {
                SPO_ARG2 = (1 << 1),
                SPO_ARG3 = (1 << 2),
                SPO_ARG4 = (1 << 3),
                SPO_ARG5 = (1 << 4),
                SPO_ARG6 = (1 << 5),
        };
    const u8 all_but2 = SPO_ARG3 | SPO_ARG4 | SPO_ARG5 | SPO_ARG6;
    const u8 all = SPO_ARG2 | all_but2;
    const u8 masks[] = {
        [PR_GET_DUMPABLE]    = all,
        [PR_SET_DUMPABLE]    = all_but2,
        [PR_SET_NAME]        = all_but2,
        [PR_GET_CHILD_SUBREAPER] = all_but2,
        [PR_SET_CHILD_SUBREAPER] = all_but2,
        [PR_GET_SECUREBITS]  = all,
        [PR_SET_SECUREBITS]  = all_but2,
        [PR_SET_MM]      = SPO_ARG4 | SPO_ARG5 | SPO_ARG6,
        [PR_GET_PDEATHSIG]   = all,
        [PR_SET_PDEATHSIG]   = all_but2,
    };

    if (option < ARRAY_SIZE(masks))
        arg->mask |= masks[option];

    return prctl__scnprintf_option(option, bf, size);
}