The patch titled
Subject: prctl: remove non PR_SET_MM_MAP operations
has been removed from the -mm tree. Its filename was
prctl-deprecate-non-pr_set_mm_map-operations.patch
This patch was dropped because it was withdrawn
------------------------------------------------------
From: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
Subject: prctl: remove non PR_SET_MM_MAP operations
An ability to manipulate mm_struct fields was introduced fort he sake of
CRIU originally. Later we provided a more suitable and safe operation
PR_SET_MM_MAP where all fields to be modifed are passed in one structure
which allows us to make more detailed verification.
The old interface remains present for compatibility reasons though CRIU
itself switched to PR_SET_MM_MAP on its own long ago.
Googling didn't reveal other users of this operation so I think it should
be safe to remove this interface.
Taking into account how special this code is (and I spent significant
amount of time trying to find a real example of its usage outside of
criu) I think it should be safe to simply remove it.
[sergey.senozhatsky@xxxxxxxxx: don't compile some of prctl functions when CRUI disabled]
Link: http://lkml.kernel.org/r/20180420072903.GA594@jagdpanzerIV
Link: http://lkml.kernel.org/r/20180405182651.GM15783@xxxxxxxxxx
Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Cc: Andrey Vagin <avagin@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/sys.c | 277 +++++++++++--------------------------------------
1 file changed, 65 insertions(+), 212 deletions(-)
diff -puN kernel/sys.c~prctl-deprecate-non-pr_set_mm_map-operations kernel/sys.c
--- a/kernel/sys.c~prctl-deprecate-non-pr_set_mm_map-operations
+++ a/kernel/sys.c
@@ -1815,68 +1815,7 @@ SYSCALL_DEFINE1(umask, int, mask)
return mask;
}
-static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
-{
- struct fd exe;
- struct file *old_exe, *exe_file;
- struct inode *inode;
- int err;
-
- exe = fdget(fd);
- if (!exe.file)
- return -EBADF;
-
- inode = file_inode(exe.file);
-
- /*
- * Because the original mm->exe_file points to executable file, make
- * sure that this one is executable as well, to avoid breaking an
- * overall picture.
- */
- err = -EACCES;
- if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
- goto exit;
-
- err = inode_permission(inode, MAY_EXEC);
- if (err)
- goto exit;
-
- /*
- * Forbid mm->exe_file change if old file still mapped.
- */
- exe_file = get_mm_exe_file(mm);
- err = -EBUSY;
- if (exe_file) {
- struct vm_area_struct *vma;
-
- down_read(&mm->mmap_sem);
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- if (!vma->vm_file)
- continue;
- if (path_equal(&vma->vm_file->f_path,
- &exe_file->f_path))
- goto exit_err;
- }
-
- up_read(&mm->mmap_sem);
- fput(exe_file);
- }
-
- err = 0;
- /* set the new file, lockless */
- get_file(exe.file);
- old_exe = xchg(&mm->exe_file, exe.file);
- if (old_exe)
- fput(old_exe);
-exit:
- fdput(exe);
- return err;
-exit_err:
- up_read(&mm->mmap_sem);
- fput(exe_file);
- goto exit;
-}
-
+#ifdef CONFIG_CHECKPOINT_RESTORE
/*
* WARNING: we don't require any capability here so be very careful
* in what is allowed for modification from userspace.
@@ -1968,7 +1907,68 @@ out:
return error;
}
-#ifdef CONFIG_CHECKPOINT_RESTORE
+static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
+{
+ struct fd exe;
+ struct file *old_exe, *exe_file;
+ struct inode *inode;
+ int err;
+
+ exe = fdget(fd);
+ if (!exe.file)
+ return -EBADF;
+
+ inode = file_inode(exe.file);
+
+ /*
+ * Because the original mm->exe_file points to executable file, make
+ * sure that this one is executable as well, to avoid breaking an
+ * overall picture.
+ */
+ err = -EACCES;
+ if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
+ goto exit;
+
+ err = inode_permission(inode, MAY_EXEC);
+ if (err)
+ goto exit;
+
+ /*
+ * Forbid mm->exe_file change if old file still mapped.
+ */
+ exe_file = get_mm_exe_file(mm);
+ err = -EBUSY;
+ if (exe_file) {
+ struct vm_area_struct *vma;
+
+ down_read(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (!vma->vm_file)
+ continue;
+ if (path_equal(&vma->vm_file->f_path,
+ &exe_file->f_path))
+ goto exit_err;
+ }
+
+ up_read(&mm->mmap_sem);
+ fput(exe_file);
+ }
+
+ err = 0;
+ /* set the new file, lockless */
+ get_file(exe.file);
+ old_exe = xchg(&mm->exe_file, exe.file);
+ if (old_exe)
+ fput(old_exe);
+exit:
+ fdput(exe);
+ return err;
+exit_err:
+ up_read(&mm->mmap_sem);
+ fput(exe_file);
+ goto exit;
+}
+
static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
{
struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
@@ -2059,163 +2059,16 @@ static int prctl_set_mm_map(int opt, con
}
#endif /* CONFIG_CHECKPOINT_RESTORE */
-static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
- unsigned long len)
-{
- /*
- * This doesn't move the auxiliary vector itself since it's pinned to
- * mm_struct, but it permits filling the vector with new values. It's
- * up to the caller to provide sane values here, otherwise userspace
- * tools which use this vector might be unhappy.
- */
- unsigned long user_auxv[AT_VECTOR_SIZE];
-
- if (len > sizeof(user_auxv))
- return -EINVAL;
-
- if (copy_from_user(user_auxv, (const void __user *)addr, len))
- return -EFAULT;
-
- /* Make sure the last entry is always AT_NULL */
- user_auxv[AT_VECTOR_SIZE - 2] = 0;
- user_auxv[AT_VECTOR_SIZE - 1] = 0;
-
- BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
-
- task_lock(current);
- memcpy(mm->saved_auxv, user_auxv, len);
- task_unlock(current);
-
- return 0;
-}
-
static int prctl_set_mm(int opt, unsigned long addr,
unsigned long arg4, unsigned long arg5)
{
- struct mm_struct *mm = current->mm;
- struct prctl_mm_map prctl_map;
- struct vm_area_struct *vma;
- int error;
-
- if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
- opt != PR_SET_MM_MAP &&
- opt != PR_SET_MM_MAP_SIZE)))
- return -EINVAL;
-
#ifdef CONFIG_CHECKPOINT_RESTORE
if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
#endif
- if (!capable(CAP_SYS_RESOURCE))
- return -EPERM;
-
- if (opt == PR_SET_MM_EXE_FILE)
- return prctl_set_mm_exe_file(mm, (unsigned int)addr);
-
- if (opt == PR_SET_MM_AUXV)
- return prctl_set_auxv(mm, addr, arg4);
-
- if (addr >= TASK_SIZE || addr < mmap_min_addr)
- return -EINVAL;
-
- error = -EINVAL;
-
- down_write(&mm->mmap_sem);
- vma = find_vma(mm, addr);
-
- prctl_map.start_code = mm->start_code;
- prctl_map.end_code = mm->end_code;
- prctl_map.start_data = mm->start_data;
- prctl_map.end_data = mm->end_data;
- prctl_map.start_brk = mm->start_brk;
- prctl_map.brk = mm->brk;
- prctl_map.start_stack = mm->start_stack;
- prctl_map.arg_start = mm->arg_start;
- prctl_map.arg_end = mm->arg_end;
- prctl_map.env_start = mm->env_start;
- prctl_map.env_end = mm->env_end;
- prctl_map.auxv = NULL;
- prctl_map.auxv_size = 0;
- prctl_map.exe_fd = -1;
-
- switch (opt) {
- case PR_SET_MM_START_CODE:
- prctl_map.start_code = addr;
- break;
- case PR_SET_MM_END_CODE:
- prctl_map.end_code = addr;
- break;
- case PR_SET_MM_START_DATA:
- prctl_map.start_data = addr;
- break;
- case PR_SET_MM_END_DATA:
- prctl_map.end_data = addr;
- break;
- case PR_SET_MM_START_STACK:
- prctl_map.start_stack = addr;
- break;
- case PR_SET_MM_START_BRK:
- prctl_map.start_brk = addr;
- break;
- case PR_SET_MM_BRK:
- prctl_map.brk = addr;
- break;
- case PR_SET_MM_ARG_START:
- prctl_map.arg_start = addr;
- break;
- case PR_SET_MM_ARG_END:
- prctl_map.arg_end = addr;
- break;
- case PR_SET_MM_ENV_START:
- prctl_map.env_start = addr;
- break;
- case PR_SET_MM_ENV_END:
- prctl_map.env_end = addr;
- break;
- default:
- goto out;
- }
-
- error = validate_prctl_map(&prctl_map);
- if (error)
- goto out;
-
- switch (opt) {
- /*
- * If command line arguments and environment
- * are placed somewhere else on stack, we can
- * set them up here, ARG_START/END to setup
- * command line argumets and ENV_START/END
- * for environment.
- */
- case PR_SET_MM_START_STACK:
- case PR_SET_MM_ARG_START:
- case PR_SET_MM_ARG_END:
- case PR_SET_MM_ENV_START:
- case PR_SET_MM_ENV_END:
- if (!vma) {
- error = -EFAULT;
- goto out;
- }
- }
-
- mm->start_code = prctl_map.start_code;
- mm->end_code = prctl_map.end_code;
- mm->start_data = prctl_map.start_data;
- mm->end_data = prctl_map.end_data;
- mm->start_brk = prctl_map.start_brk;
- mm->brk = prctl_map.brk;
- mm->start_stack = prctl_map.start_stack;
- mm->arg_start = prctl_map.arg_start;
- mm->arg_end = prctl_map.arg_end;
- mm->env_start = prctl_map.env_start;
- mm->env_end = prctl_map.env_end;
-
- error = 0;
-out:
- up_write(&mm->mmap_sem);
- return error;
+ pr_warn_once("PR_SET_MM_* has been removed. Use PR_SET_MM_MAP instead\n");
+ return -EINVAL;
}
#ifdef CONFIG_CHECKPOINT_RESTORE
_
Patches currently in -mm which might be from gorcunov@xxxxxxxxx are
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
