[PATCH 3.14 084/130] scripts: recordmcount: break hardlinks

From: Greg Kroah-Hartman
Date: Tue Mar 01 2016 - 18:52:00 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>

commit dd39a26538e37f6c6131e829a4a510787e43c783 upstream.

recordmcount edits the file in-place, which can cause problems when
using ccache in hardlink mode. Arrange for recordmcount to break a
hardlinked object.

Link: http://lkml.kernel.org/r/E1a7MVT-0000et-62@xxxxxxxxxxxxxxxxxxxxxxx

Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
scripts/recordmcount.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -189,6 +189,20 @@ 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;
}