initramfs: poison freed initrd memory

Various architectures including x86 poison the freed initrd memory.  Do
the same in the generic free_initrd_mem implementation and switch a few
more architectures that are identical to the generic code over to it now.

Link: http://lkml.kernel.org/r/20190213174621.29297-9-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Steven Price <steven.price@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mips/mm/init.c

@@ -504,14 +504,6 @@ void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
-			   "initrd");
-}
-#endif
-
 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 
 void __ref free_initmem(void)

arch/s390/mm/init.c

@@ -157,14 +157,6 @@ void free_initmem(void)
 	free_initmem_default(POISON_FREE_INITMEM);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
-			   "initrd");
-}
-#endif
-
 unsigned long memory_block_size_bytes(void)
 {
 	/*

arch/sparc/mm/init_32.c

@@ -299,14 +299,6 @@ void free_initmem (void)
 	free_initmem_default(POISON_FREE_INITMEM);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
-			   "initrd");
-}
-#endif
-
 void sparc_flush_page_to_ram(struct page *page)
 {
 	unsigned long vaddr = (unsigned long)page_address(page);

arch/sparc/mm/init_64.c

@@ -2572,14 +2572,6 @@ void free_initmem(void)
 	}
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
-			   "initrd");
-}
-#endif
-
 pgprot_t PAGE_KERNEL __read_mostly;
 EXPORT_SYMBOL(PAGE_KERNEL);
 

init/initramfs.c

@@ -529,7 +529,8 @@ extern unsigned long __initramfs_size;
 
 void __weak free_initrd_mem(unsigned long start, unsigned long end)
 {
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
+			"initrd");
 }
 
 #ifdef CONFIG_KEXEC_CORE