diff options
| -rw-r--r-- | linux-user/qemu.h | 3 | ||||
| -rw-r--r-- | linux-user/syscall.c | 54 |
2 files changed, 38 insertions, 19 deletions
diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 92f9f5a..a5830ec 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -165,6 +165,9 @@ typedef struct TaskState { } TaskState; abi_long do_brk(abi_ulong new_brk); +int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname, + int flags, mode_t mode); +ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz); /* user access */ diff --git a/linux-user/syscall.c b/linux-user/syscall.c index f2cb101..fa83737 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8448,7 +8448,8 @@ static int open_hardware(CPUArchState *cpu_env, int fd) } #endif -static int do_openat(CPUArchState *cpu_env, int dirfd, const char *pathname, int flags, mode_t mode) +int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname, + int flags, mode_t mode) { struct fake_open { const char *filename; @@ -8520,6 +8521,36 @@ static int do_openat(CPUArchState *cpu_env, int dirfd, const char *pathname, int return safe_openat(dirfd, path(pathname), flags, mode); } +ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz) +{ + ssize_t ret; + + if (!pathname || !buf) { + errno = EFAULT; + return -1; + } + + if (!bufsiz) { + /* Short circuit this for the magic exe check. */ + errno = EINVAL; + return -1; + } + + if (is_proc_myself((const char *)pathname, "exe")) { + /* + * Don't worry about sign mismatch as earlier mapping + * logic would have thrown a bad address error. + */ + ret = MIN(strlen(exec_path), bufsiz); + /* We cannot NUL terminate the string. */ + memcpy(buf, exec_path, ret); + } else { + ret = readlink(path(pathname), buf, bufsiz); + } + + return ret; +} + static int do_execveat(CPUArchState *cpu_env, int dirfd, abi_long pathname, abi_long guest_argp, abi_long guest_envp, int flags) @@ -8994,7 +9025,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, case TARGET_NR_open: if (!(p = lock_user_string(arg1))) return -TARGET_EFAULT; - ret = get_errno(do_openat(cpu_env, AT_FDCWD, p, + ret = get_errno(do_guest_openat(cpu_env, AT_FDCWD, p, target_to_host_bitmask(arg2, fcntl_flags_tbl), arg3)); fd_trans_unregister(ret); @@ -9004,7 +9035,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, case TARGET_NR_openat: if (!(p = lock_user_string(arg2))) return -TARGET_EFAULT; - ret = get_errno(do_openat(cpu_env, arg1, p, + ret = get_errno(do_guest_openat(cpu_env, arg1, p, target_to_host_bitmask(arg3, fcntl_flags_tbl), arg4)); fd_trans_unregister(ret); @@ -10229,22 +10260,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, void *p2; p = lock_user_string(arg1); p2 = lock_user(VERIFY_WRITE, arg2, arg3, 0); - if (!p || !p2) { - ret = -TARGET_EFAULT; - } else if (!arg3) { - /* Short circuit this for the magic exe check. */ - ret = -TARGET_EINVAL; - } else if (is_proc_myself((const char *)p, "exe")) { - /* - * Don't worry about sign mismatch as earlier mapping - * logic would have thrown a bad address error. - */ - ret = MIN(strlen(exec_path), arg3); - /* We cannot NUL terminate the string. */ - memcpy(p2, exec_path, ret); - } else { - ret = get_errno(readlink(path(p), p2, arg3)); - } + ret = get_errno(do_guest_readlink(p, p2, arg3)); unlock_user(p2, arg2, ret); unlock_user(p, arg1, 0); } |