[PATCH 3.4 090/125] scripts: recordmcount: break hardlinks

From: lizf
Date: Wed Oct 12 2016 - 08:55:05 EST


From: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>

3.4.113-rc1 review patch. If anyone has any objections, please let me know.

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


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: Zefan Li <lizefan@xxxxxxxxxx>
---
scripts/recordmcount.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index ee52cb8..4eb047a 100644
--- 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;
}

--
1.9.1