Re: [PATCH] scripts: recordmcount: break hardlinks

Steven Rostedt
2015-12-11T14:31:31Z

On Fri, 11 Dec 2015 12:09:03 +0000
Russell King <rmk+kernel@arm.linux.org.uk> wrote:

> recordmcount edits the file in-place, which can cause problems when
> using ccache in hardlink mode. Arrange for recordmcount to break a
> hardlinked object.
>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
> Steven, sorry it took a while to get this out...

Should this be for stable, or is it fine to just add this to my 4.5
queue?

-- Steve

>
> scripts/recordmcount.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
> index 698768bdc581..91705ef30402 100644
> --- a/scripts/recordmcount.c
> +++ b/scripts/recordmcount.c
> @@ -211,6 +211,20 @@ static void *mmap_file(char const *fname)
> addr = umalloc(sb.st_size);
> uread(fd_map, addr, sb.st_size);
> }
> + if (sb.st_nlink != 1) {
> + /* file is hard-linked, break the hard link */
> + close(fd_map);
> + if (unlink(fname) < 0) {
> + perror(fname);
> + fail_file();
> + }
> + fd_map = open(fname, O_RDWR | O_CREAT, sb.st_mode);
> + if (fd_map < 0) {
> + perror(fname);
> + fail_file();
> + }
> + uwrite(fd_map, addr, sb.st_size);
> + }
> return addr;
> }
>