savecore: decrease filename buffer sizes

All files are now created relative to savedirfd, e.g. with openat(2).
Therefore, we do not need character buffers to be PATH_MAX bytes long,
just long enough to hold the complete filename. 32 bytes is long enough
in all cases. These can be allocated on the stack.

While here, fix an error message that attempts to use an uninitialized
infoname.

Reviewed by:	markj
MFC after:	3 days
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D34821

1 files changed, 5 insertions, 6 deletions

diff --git a/sbin/savecore/savecore.c b/sbin/savecore/savecore.c
index 7f84f8805659..84676e1c79cb 100644
--- a/sbin/savecore/savecore.c
+++ b/sbin/savecore/savecore.c
@@ -318,7 +318,7 @@ file_size(int savedirfd, const char *path)
 static off_t
 saved_dump_size(int savedirfd, int bounds)
 {
-	static char path[PATH_MAX];
+	char path[32];
 	off_t dumpsize;
 
 	dumpsize = 0;
@@ -342,7 +342,7 @@ saved_dump_size(int savedirfd, int bounds)
 static void
 saved_dump_remove(int savedirfd, int bounds)
 {
-	static char path[PATH_MAX];
+	char path[32];
 
 	(void)snprintf(path, sizeof(path), "info.%d", bounds);
 	(void)unlinkat(savedirfd, path, 0);
@@ -697,10 +697,9 @@ DoTextdumpFile(int fd, off_t dumpsize, off_t lasthd, char *buf,
 static void
 DoFile(const char *savedir, int savedirfd, const char *device)
 {
-	xo_handle_t *xostdout, *xoinfo;
-	static char infoname[PATH_MAX], corename[PATH_MAX], linkname[PATH_MAX];
-	static char keyname[PATH_MAX];
 	static char *buf = NULL;
+	xo_handle_t *xostdout, *xoinfo;
+	char infoname[32], corename[32], linkname[32], keyname[32];
 	char *temp = NULL;
 	struct kerneldumpheader kdhf, kdhl;
 	uint8_t *dumpkey;
@@ -719,7 +718,7 @@ DoFile(const char *savedir, int savedirfd, const char *device)
 
 	xostdout = xo_create_to_file(stdout, XO_STYLE_TEXT, 0);
 	if (xostdout == NULL) {
-		logmsg(LOG_ERR, "%s: %m", infoname);
+		logmsg(LOG_ERR, "xo_create_to_file() failed: %m");
 		return;
 	}