[patch 24/38] swiotlb: add checks for the return value of memblock_alloc*()

[akpm@xxxxxxxxxxxxxxxxxxxx]

From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Subject: swiotlb: 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/1548057848-15136-19-git-send-email-rppt@xxxxxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Greentime Hu <green.hu@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Guan Xuetao <gxt@xxxxxxxxxx>
Cc: Guo Ren <guoren@xxxxxxxxxx>
Cc: Guo Ren <ren_guo@xxxxxxxxx>				[c-sky]
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>			[Xen]
Cc: Mark Salter <msalter@xxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Simek <monstr@xxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Stafford Horne <shorne@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---


--- a/kernel/dma/swiotlb.c~swiotlb-add-checks-for-the-return-value-of-memblock_alloc
+++ a/kernel/dma/swiotlb.c
@@ -199,6 +199,7 @@ void __init swiotlb_update_mem_attribute
 int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 {
 	unsigned long i, bytes;
+	size_t alloc_size;
 
 	bytes = nslabs << IO_TLB_SHIFT;
 
@@ -211,12 +212,18 @@ int __init swiotlb_init_with_tbl(char *t
 	 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
 	 * between io_tlb_start and io_tlb_end.
 	 */
-	io_tlb_list = memblock_alloc(
-				PAGE_ALIGN(io_tlb_nslabs * sizeof(int)),
-				PAGE_SIZE);
-	io_tlb_orig_addr = memblock_alloc(
-				PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)),
-				PAGE_SIZE);
+	alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int));
+	io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE);
+	if (!io_tlb_list)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, alloc_size, PAGE_SIZE);
+
+	alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t));
+	io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE);
+	if (!io_tlb_orig_addr)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, alloc_size, PAGE_SIZE);
+
 	for (i = 0; i < io_tlb_nslabs; i++) {
 		io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
 		io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
_