[PATCH 3.2 16/70] scripts: recordmcount: break hardlinks

Ben Hutchings
2016-01-18T03:35:29Z

From: Russell King <rmk+kernel@arm.linux.org.uk>

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@rmk-PC.arm.linux.org.uk

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
scripts/recordmcount.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -182,6 +182,20 @@ 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;
}