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/1548057848-15136-18-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>				[c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com>			[Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c

@@ -373,12 +373,20 @@ static inline void smp_prepare_cpus(unsigned int maxcpus) { }
  */
 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);
 }
@@ -770,8 +778,14 @@ static int __init initcall_blacklist(char *str)
 			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);
 		}