init/main: add checks for the return value of memblock_alloc*()

Add panic() calls if memblock_alloc() returns NULL.

The panic() format duplicates the one used by memblock itself and in
order to avoid explosion with long parameters list replace open coded
allocation size calculations with a local variable.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Mike Rapoport <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Christophe Leroy <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Dennis Zhou <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Cc: Greentime Hu <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Guan Xuetao <[e-mail]>
Cc: Guo Ren <[e-mail]>
Cc: Guo Ren <[e-mail]> [c-sky]
Cc: Heiko Carstens <[e-mail]>
Cc: Juergen Gross <[e-mail]> [Xen]
Cc: Mark Salter <[e-mail]>
Cc: Matt Turner <[e-mail]>
Cc: Max Filippov <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Michal Simek <[e-mail]>
Cc: Paul Burton <[e-mail]>
Cc: Petr Mladek <[e-mail]>
Cc: Richard Weinberger <[e-mail]>
Cc: Rich Felker <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Stafford Horne <[e-mail]>
Cc: Tony Luck <[e-mail]>
Cc: Vineet Gupta <[e-mail]>
Cc: Yoshinori Sato <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

init/main.c

···
  */
 static void __init setup_command_line(char *command_line)
 {
-	saved_command_line =
-		memblock_alloc(strlen(boot_command_line) + 1, SMP_CACHE_BYTES);
-	initcall_command_line =
-		memblock_alloc(strlen(boot_command_line) + 1, SMP_CACHE_BYTES);
-	static_command_line = memblock_alloc(strlen(command_line) + 1,
-					     SMP_CACHE_BYTES);
+	size_t len = strlen(boot_command_line) + 1;
+
+	saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!saved_command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	initcall_command_line =	memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!initcall_command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!static_command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
 	strcpy(saved_command_line, boot_command_line);
 	strcpy(static_command_line, command_line);
 }
···
 			pr_debug("blacklisting initcall %s\n", str_entry);
 			entry = memblock_alloc(sizeof(*entry),
 					       SMP_CACHE_BYTES);
+			if (!entry)
+				panic("%s: Failed to allocate %zu bytes\n",
+				      __func__, sizeof(*entry));
 			entry->buf = memblock_alloc(strlen(str_entry) + 1,
 						    SMP_CACHE_BYTES);
+			if (!entry->buf)
+				panic("%s: Failed to allocate %zu bytes\n",
+				      __func__, strlen(str_entry) + 1);
 			strcpy(entry->buf, str_entry);
 			list_add(&entry->next, &blacklisted_initcalls);
 		}