Commit e0eb210e authored by Peter Maydell's avatar Peter Maydell Committed by Riku Voipio
Browse files

linux-user: Implement capget, capset 



Implement the capget and capset syscalls. This is useful because
simple programs like 'ls' try to use it in AArch64, and otherwise
we emit a lot of noise about it being unimplemented.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarRiku Voipio <riku.voipio@linaro.org>
parent a7ec0f98

linux-user/syscall.c

+73 −2
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <sys/resource.h>

#include <sys/mman.h>

#include <sys/swap.h>

#include <linux/capability.h>

#include <signal.h>

#include <sched.h>

#ifdef __ia64__
@@ -243,6 +244,10 @@ _syscall3(int, sys_sched_setaffinity, pid_t, pid, unsigned int, len, 
          unsigned long *, user_mask_ptr);

_syscall4(int, reboot, int, magic1, int, magic2, unsigned int, cmd,

          void *, arg);

_syscall2(int, capget, struct __user_cap_header_struct *, header,

          struct __user_cap_data_struct *, data);

_syscall2(int, capset, struct __user_cap_header_struct *, header,

          struct __user_cap_data_struct *, data);



static bitmask_transtbl fcntl_flags_tbl[] = {

  { TARGET_O_ACCMODE,   TARGET_O_WRONLY,    O_ACCMODE,   O_WRONLY,    },
@@ -7677,9 +7682,75 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, 
        unlock_user(p, arg1, ret);

        break;

    case TARGET_NR_capget:

        goto unimplemented;

    case TARGET_NR_capset:

        goto unimplemented;

    {

        struct target_user_cap_header *target_header;

        struct target_user_cap_data *target_data = NULL;

        struct __user_cap_header_struct header;

        struct __user_cap_data_struct data[2];

        struct __user_cap_data_struct *dataptr = NULL;

        int i, target_datalen;

        int data_items = 1;



        if (!lock_user_struct(VERIFY_WRITE, target_header, arg1, 1)) {

            goto efault;

        }

        header.version = tswap32(target_header->version);

        header.pid = tswap32(target_header->pid);



        if (header.version != _LINUX_CAPABILITY_VERSION_1) {

            /* Version 2 and up takes pointer to two user_data structs */

            data_items = 2;

        }



        target_datalen = sizeof(*target_data) * data_items;



        if (arg2) {

            if (num == TARGET_NR_capget) {

                target_data = lock_user(VERIFY_WRITE, arg2, target_datalen, 0);

            } else {

                target_data = lock_user(VERIFY_READ, arg2, target_datalen, 1);

            }

            if (!target_data) {

                unlock_user_struct(target_header, arg1, 0);

                goto efault;

            }



            if (num == TARGET_NR_capset) {

                for (i = 0; i < data_items; i++) {

                    data[i].effective = tswap32(target_data[i].effective);

                    data[i].permitted = tswap32(target_data[i].permitted);

                    data[i].inheritable = tswap32(target_data[i].inheritable);

                }

            }



            dataptr = data;

        }



        if (num == TARGET_NR_capget) {

            ret = get_errno(capget(&header, dataptr));

        } else {

            ret = get_errno(capset(&header, dataptr));

        }



        /* The kernel always updates version for both capget and capset */

        target_header->version = tswap32(header.version);

        unlock_user_struct(target_header, arg1, 1);



        if (arg2) {

            if (num == TARGET_NR_capget) {

                for (i = 0; i < data_items; i++) {

                    target_data[i].effective = tswap32(data[i].effective);

                    target_data[i].permitted = tswap32(data[i].permitted);

                    target_data[i].inheritable = tswap32(data[i].inheritable);

                }

                unlock_user(target_data, arg2, target_datalen);

            } else {

                unlock_user(target_data, arg2, 0);

            }

        }

        break;

    }

    case TARGET_NR_sigaltstack:

#if defined(TARGET_I386) || defined(TARGET_ARM) || defined(TARGET_MIPS) || \

    defined(TARGET_SPARC) || defined(TARGET_PPC) || defined(TARGET_ALPHA) || \

linux-user/syscall_defs.h

+11 −0
Original line number Diff line number Diff line
@@ -2566,3 +2566,14 @@ struct target_sigevent { 
        } _sigev_thread;

    } _sigev_un;

};



struct target_user_cap_header {

    uint32_t version;

    int pid;

};



struct target_user_cap_data {

    uint32_t effective;

    uint32_t permitted;

    uint32_t inheritable;

};