[PATCH 1/1] lmb: do not panic in lmb_print_region_flags

[Heinrich Schuchardt]

Commit c3cf0dc64f1c ("lmb: add a check to prevent memory overrun")
addressed a possible buffer overrun using assert_noisy().

Resetting via panic() in lmb_print_region() while allowing invalid
lmb flags elsewhere is not reasonable.

Instead of panicking print a message indicating the problem.

fls() returns an int. Using a u64 for bitpos does not match.
Use int instead.

fls() takes an int as argument. Using 1ull << bitpos generates a u64.
Use 1u << bitpos instead.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
 lib/lmb.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/lmb.c b/lib/lmb.c
index 96a055f951e..00c8888936a 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -72,16 +72,22 @@ static int __maybe_unused lmb_map_update_notify(phys_addr_t addr,
 
 static void lmb_print_region_flags(enum lmb_flags flags)
 {
-	u64 bitpos;
 	const char *flag_str[] = { "none", "no-map", "no-overwrite", "no-notify" };
+	unsigned int pflags = flags &
+			      (LMB_NOMAP | LMB_NOOVERWRITE | LMB_NONOTIFY);
+
+	if (flags != pflags) {
+		printf("invalid %#x\n", flags);
+		return;
+	}

 	do {
-		bitpos = flags ? fls(flags) - 1 : 0;
-		assert_noisy(bitpos < ARRAY_SIZE(flag_str));
+		int bitpos = pflags ? fls(pflags) - 1 : 0;
+
 		printf("%s", flag_str[bitpos]);
-		flags &= ~(1ull << bitpos);
-		puts(flags ? ", " : "\n");
-	} while (flags);
+		pflags &= ~(1u << bitpos);
+		puts(pflags ? ", " : "\n");
+	} while (pflags);
 }
 
 static void lmb_dump_region(struct alist *lmb_rgn_lst, char *name)
-- 
2.45.2