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-rw-r--r--kernel/sys.c121
1 files changed, 64 insertions, 57 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index 9ff89cb9657..241507f23ec 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1786,27 +1786,12 @@ SYSCALL_DEFINE1(umask, int, mask)
}
#ifdef CONFIG_CHECKPOINT_RESTORE
-static bool vma_flags_mismatch(struct vm_area_struct *vma,
- unsigned long required,
- unsigned long banned)
-{
- return (vma->vm_flags & required) != required ||
- (vma->vm_flags & banned);
-}
-
static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
{
struct file *exe_file;
struct dentry *dentry;
int err;
- /*
- * Setting new mm::exe_file is only allowed when no VM_EXECUTABLE vma's
- * remain. So perform a quick test first.
- */
- if (mm->num_exe_file_vmas)
- return -EBUSY;
-
exe_file = fget(fd);
if (!exe_file)
return -EBADF;
@@ -1827,17 +1812,35 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
if (err)
goto exit;
+ down_write(&mm->mmap_sem);
+
+ /*
+ * Forbid mm->exe_file change if old file still mapped.
+ */
+ err = -EBUSY;
+ if (mm->exe_file) {
+ struct vm_area_struct *vma;
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next)
+ if (vma->vm_file &&
+ path_equal(&vma->vm_file->f_path,
+ &mm->exe_file->f_path))
+ goto exit_unlock;
+ }
+
/*
* The symlink can be changed only once, just to disallow arbitrary
* transitions malicious software might bring in. This means one
* could make a snapshot over all processes running and monitor
* /proc/pid/exe changes to notice unusual activity if needed.
*/
- down_write(&mm->mmap_sem);
- if (likely(!mm->exe_file))
- set_mm_exe_file(mm, exe_file);
- else
- err = -EBUSY;
+ err = -EPERM;
+ if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
+ goto exit_unlock;
+
+ err = 0;
+ set_mm_exe_file(mm, exe_file);
+exit_unlock:
up_write(&mm->mmap_sem);
exit:
@@ -1862,7 +1865,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
if (opt == PR_SET_MM_EXE_FILE)
return prctl_set_mm_exe_file(mm, (unsigned int)addr);
- if (addr >= TASK_SIZE)
+ if (addr >= TASK_SIZE || addr < mmap_min_addr)
return -EINVAL;
error = -EINVAL;
@@ -1924,12 +1927,6 @@ static int prctl_set_mm(int opt, unsigned long addr,
error = -EFAULT;
goto out;
}
-#ifdef CONFIG_STACK_GROWSUP
- if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSUP, 0))
-#else
- if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSDOWN, 0))
-#endif
- goto out;
if (opt == PR_SET_MM_START_STACK)
mm->start_stack = addr;
else if (opt == PR_SET_MM_ARG_START)
@@ -1981,12 +1978,22 @@ out:
up_read(&mm->mmap_sem);
return error;
}
+
+static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
+{
+ return put_user(me->clear_child_tid, tid_addr);
+}
+
#else /* CONFIG_CHECKPOINT_RESTORE */
static int prctl_set_mm(int opt, unsigned long addr,
unsigned long arg4, unsigned long arg5)
{
return -EINVAL;
}
+static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
+{
+ return -EINVAL;
+}
#endif
SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
@@ -2008,7 +2015,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
break;
}
me->pdeath_signal = arg2;
- error = 0;
break;
case PR_GET_PDEATHSIG:
error = put_user(me->pdeath_signal, (int __user *)arg2);
@@ -2022,7 +2028,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
break;
}
set_dumpable(me->mm, arg2);
- error = 0;
break;
case PR_SET_UNALIGN:
@@ -2049,10 +2054,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
case PR_SET_TIMING:
if (arg2 != PR_TIMING_STATISTICAL)
error = -EINVAL;
- else
- error = 0;
break;
-
case PR_SET_NAME:
comm[sizeof(me->comm)-1] = 0;
if (strncpy_from_user(comm, (char __user *)arg2,
@@ -2060,20 +2062,19 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
return -EFAULT;
set_task_comm(me, comm);
proc_comm_connector(me);
- return 0;
+ break;
case PR_GET_NAME:
get_task_comm(comm, me);
if (copy_to_user((char __user *)arg2, comm,
sizeof(comm)))
return -EFAULT;
- return 0;
+ break;
case PR_GET_ENDIAN:
error = GET_ENDIAN(me, arg2);
break;
case PR_SET_ENDIAN:
error = SET_ENDIAN(me, arg2);
break;
-
case PR_GET_SECCOMP:
error = prctl_get_seccomp();
break;
@@ -2101,7 +2102,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
current->default_timer_slack_ns;
else
current->timer_slack_ns = arg2;
- error = 0;
break;
case PR_MCE_KILL:
if (arg4 | arg5)
@@ -2127,7 +2127,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
default:
return -EINVAL;
}
- error = 0;
break;
case PR_MCE_KILL_GET:
if (arg2 | arg3 | arg4 | arg5)
@@ -2141,9 +2140,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
case PR_SET_MM:
error = prctl_set_mm(arg2, arg3, arg4, arg5);
break;
+ case PR_GET_TID_ADDRESS:
+ error = prctl_get_tid_address(me, (int __user **)arg2);
+ break;
case PR_SET_CHILD_SUBREAPER:
me->signal->is_child_subreaper = !!arg2;
- error = 0;
break;
case PR_GET_CHILD_SUBREAPER:
error = put_user(me->signal->is_child_subreaper,
@@ -2185,46 +2186,52 @@ static void argv_cleanup(struct subprocess_info *info)
argv_free(info->argv);
}
-/**
- * orderly_poweroff - Trigger an orderly system poweroff
- * @force: force poweroff if command execution fails
- *
- * This may be called from any context to trigger a system shutdown.
- * If the orderly shutdown fails, it will force an immediate shutdown.
- */
-int orderly_poweroff(bool force)
+static int __orderly_poweroff(void)
{
int argc;
- char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
+ char **argv;
static char *envp[] = {
"HOME=/",
"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
NULL
};
- int ret = -ENOMEM;
+ int ret;
+ argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
if (argv == NULL) {
printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
__func__, poweroff_cmd);
- goto out;
+ return -ENOMEM;
}
ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_NO_WAIT,
NULL, argv_cleanup, NULL);
-out:
- if (likely(!ret))
- return 0;
-
if (ret == -ENOMEM)
argv_free(argv);
- if (force) {
+ return ret;
+}
+
+/**
+ * orderly_poweroff - Trigger an orderly system poweroff
+ * @force: force poweroff if command execution fails
+ *
+ * This may be called from any context to trigger a system shutdown.
+ * If the orderly shutdown fails, it will force an immediate shutdown.
+ */
+int orderly_poweroff(bool force)
+{
+ int ret = __orderly_poweroff();
+
+ if (ret && force) {
printk(KERN_WARNING "Failed to start orderly shutdown: "
"forcing the issue\n");
- /* I guess this should try to kick off some daemon to
- sync and poweroff asap. Or not even bother syncing
- if we're doing an emergency shutdown? */
+ /*
+ * I guess this should try to kick off some daemon to sync and
+ * poweroff asap. Or not even bother syncing if we're doing an
+ * emergency shutdown?
+ */
emergency_sync();
kernel_power_off();
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-24 04:39:55 +0000